264 files changed, 4018 insertions, 1973 deletions
diff --git a/.travis.yml b/.travis.yml
index c198cc5f7..d4cf71ab5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -58,7 +58,7 @@ deploy:
    provider: pages
    skip-cleanup: true
    github-token: $DOCS_TOKEN  # Set in the settings page of your repository, as a secure variable
-    keep-history: true
+    keep-history: false
    local-dir: target/website/
    on:
        branch: master
diff --git a/Cargo.lock b/Cargo.lock
index dad9b1df1..e9383a89a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -32,11 +32,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "backtrace"
-version = "0.3.37"
+version = "0.3.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)",
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -46,7 +46,7 @@ name = "backtrace-sys"
 version = "0.1.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cc 1.0.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -73,7 +73,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "bitflags"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -104,19 +104,19 @@ version = "0.8.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "cc"
-version = "1.0.42"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "cfg-if"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -200,7 +200,7 @@ name = "cloudabi"
 version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -223,7 +223,7 @@ name = "crossbeam"
 version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam-channel 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam-epoch 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -254,7 +254,7 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "memoffset 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -274,7 +274,7 @@ name = "crossbeam-utils"
 version = "0.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -283,7 +283,7 @@ name = "derive-new"
 version = "0.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -305,7 +305,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "either"
-version = "1.5.2"
+version = "1.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -326,7 +326,7 @@ name = "filetime"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -339,7 +339,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "flexi_logger"
-version = "0.14.3"
+version = "0.14.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "chrono 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -369,7 +369,7 @@ name = "fsevent"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "fsevent-sys 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -399,7 +399,7 @@ name = "fuchsia-zircon"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -410,12 +410,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "getrandom"
-version = "0.1.11"
+version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
- "wasi 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -455,7 +455,7 @@ dependencies = [
 [[package]]
 name = "indexmap"
-version = "1.1.0"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -475,7 +475,7 @@ name = "inotify"
 version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "inotify-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -496,7 +496,7 @@ dependencies = [
 "console 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_yaml 0.8.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "uuid 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -516,7 +516,7 @@ name = "itertools"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "either 1.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "either 1.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -539,7 +539,7 @@ name = "jemalloc-sys"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cc 1.0.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.45 (registry+https://github.com/rust-lang/crates.io-index)",
 "fs_extra 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -610,7 +610,7 @@ name = "log"
 version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -620,7 +620,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "crossbeam-channel 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -629,8 +629,8 @@ name = "lsp-types"
 version = "0.61.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_repr 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "url 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -698,7 +698,7 @@ name = "net2"
 version = "0.2.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -713,7 +713,7 @@ name = "notify"
 version = "4.0.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "filetime 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
 "fsevent 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "fsevent-sys 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -761,7 +761,7 @@ dependencies = [
 [[package]]
 name = "once_cell"
-version = "1.0.2"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -784,7 +784,7 @@ name = "parking_lot_core"
 version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
 "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -808,7 +808,7 @@ version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro-hack 0.5.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -829,7 +829,7 @@ dependencies = [
 [[package]]
 name = "pico-args"
-version = "0.2.0"
+version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -842,14 +842,14 @@ name = "proc-macro-hack"
 version = "0.5.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "proc-macro2"
-version = "1.0.2"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -861,7 +861,7 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -882,7 +882,7 @@ name = "quote"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro2 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -897,7 +897,7 @@ dependencies = [
 "format-buf 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "once_cell 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "once_cell 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_db 0.1.0",
 "ra_fmt 0.1.0",
 "ra_hir 0.1.0",
@@ -924,12 +924,22 @@ dependencies = [
 ]
 [[package]]
+name = "ra_cfg"
+version = "0.1.0"
+dependencies = [
+ "ra_mbe 0.1.0",
+ "ra_syntax 0.1.0",
+ "ra_tt 0.1.0",
+ "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "ra_cli"
 version = "0.1.0"
 dependencies = [
- "flexi_logger 0.14.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "flexi_logger 0.14.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "indicatif 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "pico-args 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pico-args 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_batch 0.1.0",
 "ra_db 0.1.0",
 "ra_hir 0.1.0",
@@ -942,11 +952,12 @@ dependencies = [
 name = "ra_db"
 version = "0.1.0"
 dependencies = [
+ "ra_cfg 0.1.0",
 "ra_prof 0.1.0",
 "ra_syntax 0.1.0",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "salsa 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -969,9 +980,10 @@ dependencies = [
 "insta 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lalrpop-intern 0.15.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "once_cell 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "once_cell 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_arena 0.1.0",
+ "ra_cfg 0.1.0",
 "ra_db 0.1.0",
 "ra_mbe 0.1.0",
 "ra_prof 0.1.0",
@@ -994,13 +1006,14 @@ dependencies = [
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_assists 0.1.0",
+ "ra_cfg 0.1.0",
 "ra_db 0.1.0",
 "ra_fmt 0.1.0",
 "ra_hir 0.1.0",
 "ra_prof 0.1.0",
 "ra_syntax 0.1.0",
 "ra_text_edit 0.1.0",
- "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "rayon 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1014,12 +1027,13 @@ name = "ra_lsp_server"
 version = "0.1.0"
 dependencies = [
 "crossbeam-channel 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "flexi_logger 0.14.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "flexi_logger 0.14.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "jod-thread 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "lsp-server 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lsp-types 0.61.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ra_cfg 0.1.0",
 "ra_db 0.1.0",
 "ra_ide_api 0.1.0",
 "ra_prof 0.1.0",
@@ -1030,7 +1044,7 @@ dependencies = [
 "ra_vfs_glob 0.1.0",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.99 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
 "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
@@ -1062,11 +1076,11 @@ dependencies = [
 name = "ra_prof"
 version = "0.1.0"
 dependencies = [
- "backtrace 0.3.37 (registry+https://github.com/rust-lang/crates.io-index)",
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@@ -1855,7 +1872,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "6ba9a427cfca2be13aa6f6403b0b7e7368fe982bfa16fccc450ce74c46cd9b32"
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@@ -1863,16 +1880,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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@@ -1901,20 +1918,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rustc_lexer 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c86aae0c77166108c01305ee1a36a1e77289d7dc6ca0a3cd91ff4992de2d16a5"
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@@ -1934,7 +1951,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum uuid 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)" = "90dbc611eb48397705a6b0f6e917da23ae517e4d127123d2cf7674206627d32a"
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diff --git a/crates/ra_assists/src/assist_ctx.rs b/crates/ra_assists/src/assist_ctx.rs
index c45262efa..189cad7d0 100644
--- a/crates/ra_assists/src/assist_ctx.rs
+++ b/crates/ra_assists/src/assist_ctx.rs
@@ -1,8 +1,10 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_db::FileRange;
 use ra_fmt::{leading_indent, reindent};
 use ra_syntax::{
-    algo::{find_covering_element, find_node_at_offset},
+    algo::{self, find_covering_element, find_node_at_offset},
    AstNode, SourceFile, SyntaxElement, SyntaxNode, SyntaxToken, TextRange, TextUnit,
    TokenAtOffset,
 };
@@ -177,6 +179,10 @@ impl AssistBuilder {
        &mut self.edit
    }
+    pub(crate) fn replace_ast<N: AstNode>(&mut self, old: N, new: N) {
+        algo::diff(old.syntax(), new.syntax()).into_text_edit(&mut self.edit)
+    }
    fn build(self) -> AssistAction {
        AssistAction {
            edit: self.edit.finish(),
diff --git a/crates/ra_assists/src/assists/add_derive.rs b/crates/ra_assists/src/assists/add_derive.rs
index 9c88644df..77ecc33c9 100644
--- a/crates/ra_assists/src/assists/add_derive.rs
+++ b/crates/ra_assists/src/assists/add_derive.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{
    ast::{self, AstNode, AttrsOwner},
@@ -13,7 +15,7 @@ pub(crate) fn add_derive(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist>
    ctx.add_action(AssistId("add_derive"), "add `#[derive]`", |edit| {
        let derive_attr = nominal
            .attrs()
-            .filter_map(|x| x.as_call())
+            .filter_map(|x| x.as_simple_call())
            .filter(|(name, _arg)| name == "derive")
            .map(|(_name, arg)| arg)
            .next();
diff --git a/crates/ra_assists/src/assists/add_explicit_type.rs b/crates/ra_assists/src/assists/add_explicit_type.rs
index 78f0f7f28..8c83dc987 100644
--- a/crates/ra_assists/src/assists/add_explicit_type.rs
+++ b/crates/ra_assists/src/assists/add_explicit_type.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{db::HirDatabase, HirDisplay, Ty};
 use ra_syntax::{
    ast::{self, AstNode, LetStmt, NameOwner},
diff --git a/crates/ra_assists/src/assists/add_impl.rs b/crates/ra_assists/src/assists/add_impl.rs
index 4b61f4031..94801fbc9 100644
--- a/crates/ra_assists/src/assists/add_impl.rs
+++ b/crates/ra_assists/src/assists/add_impl.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use format_buf::format;
 use hir::db::HirDatabase;
 use join_to_string::join;
diff --git a/crates/ra_assists/src/assists/add_missing_impl_members.rs b/crates/ra_assists/src/assists/add_missing_impl_members.rs
index 23da1e65f..565b96fb5 100644
--- a/crates/ra_assists/src/assists/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/assists/add_missing_impl_members.rs
@@ -1,10 +1,12 @@
+//! FIXME: write short doc here
 use hir::{db::HirDatabase, HasSource};
 use ra_syntax::{
-    ast::{self, make, AstNode, NameOwner},
+    ast::{self, edit, make, AstNode, NameOwner},
    SmolStr,
 };
-use crate::{ast_editor::AstEditor, Assist, AssistCtx, AssistId};
+use crate::{Assist, AssistCtx, AssistId};
 #[derive(PartialEq)]
 enum AddMissingImplMembersMode {
@@ -75,37 +77,32 @@ fn add_missing_impl_members_inner(
    ctx.add_action(AssistId(assist_id), label, |edit| {
        let n_existing_items = impl_item_list.impl_items().count();
-        let items = missing_items.into_iter().map(|it| match it {
+        let items = missing_items
-            ast::ImplItem::FnDef(def) => strip_docstring(add_body(def).into()),
+            .into_iter()
-            _ => strip_docstring(it),
+            .map(|it| match it {
-        });
+                ast::ImplItem::FnDef(def) => ast::ImplItem::FnDef(add_body(def)),
-        let mut ast_editor = AstEditor::new(impl_item_list);
+                _ => it,
+            })
-        ast_editor.append_items(items);
+            .map(|it| edit::strip_attrs_and_docs(&it));
+        let new_impl_item_list = impl_item_list.append_items(items);
-        let first_new_item = ast_editor.ast().impl_items().nth(n_existing_items).unwrap();
+        let cursor_position = {
-        let cursor_position = first_new_item.syntax().text_range().start();
+            let first_new_item = new_impl_item_list.impl_items().nth(n_existing_items).unwrap();
-        ast_editor.into_text_edit(edit.text_edit_builder());
+            first_new_item.syntax().text_range().start()
+        };
+        edit.replace_ast(impl_item_list, new_impl_item_list);
        edit.set_cursor(cursor_position);
    });
    ctx.build()
 }
-fn strip_docstring(item: ast::ImplItem) -> ast::ImplItem {
-    let mut ast_editor = AstEditor::new(item);
-    ast_editor.strip_attrs_and_docs();
-    ast_editor.ast().to_owned()
-}
 fn add_body(fn_def: ast::FnDef) -> ast::FnDef {
-    let mut ast_editor = AstEditor::new(fn_def.clone());
    if fn_def.body().is_none() {
-        let body = make::block_from_expr(make::expr_unimplemented());
+        fn_def.with_body(make::block_from_expr(make::expr_unimplemented()))
-        ast_editor.set_body(&body);
+    } else {
+        fn_def
    }
-    ast_editor.ast().to_owned()
 }
 /// Given an `ast::ImplBlock`, resolves the target trait (the one being
@@ -332,5 +329,4 @@ impl Foo for S {
 }",
        )
    }
 }
diff --git a/crates/ra_assists/src/assists/apply_demorgan.rs b/crates/ra_assists/src/assists/apply_demorgan.rs
new file mode 100644
index 000000000..5f2b0dd18
--- /dev/null
+++ b/crates/ra_assists/src/assists/apply_demorgan.rs
@@ -0,0 +1,102 @@
+//! This contains the functions associated with the demorgan assist.
+//! This assist transforms boolean expressions of the form `!a || !b` into
+//! `!(a && b)`.
+use hir::db::HirDatabase;
+use ra_syntax::ast::{self, AstNode};
+use ra_syntax::SyntaxNode;
+use crate::{Assist, AssistCtx, AssistId};
+/// Assist for applying demorgan's law
+///
+/// This transforms expressions of the form `!l || !r` into `!(l && r)`.
+/// This also works with `&&`. This assist can only be applied with the cursor
+/// on either `||` or `&&`, with both operands being a negation of some kind.
+/// This means something of the form `!x` or `x != y`.
+pub(crate) fn apply_demorgan(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let expr = ctx.node_at_offset::<ast::BinExpr>()?;
+    let op = expr.op_kind()?;
+    let op_range = expr.op_token()?.text_range();
+    let opposite_op = opposite_logic_op(op)?;
+    let cursor_in_range = ctx.frange.range.is_subrange(&op_range);
+    if !cursor_in_range {
+        return None;
+    }
+    let lhs = expr.lhs()?.syntax().clone();
+    let lhs_range = lhs.text_range();
+    let rhs = expr.rhs()?.syntax().clone();
+    let rhs_range = rhs.text_range();
+    let not_lhs = undo_negation(lhs)?;
+    let not_rhs = undo_negation(rhs)?;
+    ctx.add_action(AssistId("apply_demorgan"), "apply demorgan's law", |edit| {
+        edit.target(op_range);
+        edit.replace(op_range, opposite_op);
+        edit.replace(lhs_range, format!("!({}", not_lhs));
+        edit.replace(rhs_range, format!("{})", not_rhs));
+    });
+    ctx.build()
+}
+// Return the opposite text for a given logical operator, if it makes sense
+fn opposite_logic_op(kind: ast::BinOp) -> Option<&'static str> {
+    match kind {
+        ast::BinOp::BooleanOr => Some("&&"),
+        ast::BinOp::BooleanAnd => Some("||"),
+        _ => None,
+    }
+}
+// This function tries to undo unary negation, or inequality
+fn undo_negation(node: SyntaxNode) -> Option<String> {
+    match ast::Expr::cast(node)? {
+        ast::Expr::BinExpr(bin) => match bin.op_kind()? {
+            ast::BinOp::NegatedEqualityTest => {
+                let lhs = bin.lhs()?.syntax().text();
+                let rhs = bin.rhs()?.syntax().text();
+                Some(format!("{} == {}", lhs, rhs))
+            }
+            _ => None,
+        },
+        ast::Expr::PrefixExpr(pe) => match pe.op_kind()? {
+            ast::PrefixOp::Not => {
+                let child = pe.expr()?.syntax().text();
+                Some(String::from(child))
+            }
+            _ => None,
+        },
+        _ => None,
+    }
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+    #[test]
+    fn demorgan_turns_and_into_or() {
+        check_assist(apply_demorgan, "fn f() { !x &&<|> !x }", "fn f() { !(x ||<|> x) }")
+    }
+    #[test]
+    fn demorgan_turns_or_into_and() {
+        check_assist(apply_demorgan, "fn f() { !x ||<|> !x }", "fn f() { !(x &&<|> x) }")
+    }
+    #[test]
+    fn demorgan_removes_inequality() {
+        check_assist(apply_demorgan, "fn f() { x != x ||<|> !x }", "fn f() { !(x == x &&<|> x) }")
+    }
+    #[test]
+    fn demorgan_doesnt_apply_with_cursor_not_on_op() {
+        check_assist_not_applicable(apply_demorgan, "fn f() { <|> !x || !x }")
+    }
+    #[test]
+    fn demorgan_doesnt_apply_when_operands_arent_negated_already() {
+        check_assist_not_applicable(apply_demorgan, "fn f() { x ||<|> x }")
+    }
+}
diff --git a/crates/ra_assists/src/assists/auto_import.rs b/crates/ra_assists/src/assists/auto_import.rs
index 5aae98546..02c58e7c6 100644
--- a/crates/ra_assists/src/assists/auto_import.rs
+++ b/crates/ra_assists/src/assists/auto_import.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{self, db::HirDatabase};
 use ra_text_edit::TextEditBuilder;
@@ -448,7 +450,6 @@ fn make_assist_add_in_tree_list(
        fmt_segments_raw(target, &mut buf);
        edit.insert(offset, buf);
    } else {
    }
 }
@@ -512,7 +513,7 @@ pub fn collect_hir_path_segments(path: &hir::Path) -> Option<Vec<SmolStr>> {
        hir::PathKind::Plain => {}
        hir::PathKind::Self_ => ps.push("self".into()),
        hir::PathKind::Super => ps.push("super".into()),
-        hir::PathKind::Type(_) => return None,
+        hir::PathKind::Type(_) | hir::PathKind::DollarCrate(_) => return None,
    }
    for s in path.segments.iter() {
        ps.push(s.name.to_string().into());
diff --git a/crates/ra_assists/src/assists/change_visibility.rs b/crates/ra_assists/src/assists/change_visibility.rs
index 60c74debc..df92c6b67 100644
--- a/crates/ra_assists/src/assists/change_visibility.rs
+++ b/crates/ra_assists/src/assists/change_visibility.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{
    ast::{self, NameOwner, VisibilityOwner},
diff --git a/crates/ra_assists/src/assists/fill_match_arms.rs b/crates/ra_assists/src/assists/fill_match_arms.rs
index db82db89a..7335cce09 100644
--- a/crates/ra_assists/src/assists/fill_match_arms.rs
+++ b/crates/ra_assists/src/assists/fill_match_arms.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::iter;
 use hir::{db::HirDatabase, Adt, HasSource};
diff --git a/crates/ra_assists/src/assists/flip_binexpr.rs b/crates/ra_assists/src/assists/flip_binexpr.rs
index b55b36a8e..c51035282 100644
--- a/crates/ra_assists/src/assists/flip_binexpr.rs
+++ b/crates/ra_assists/src/assists/flip_binexpr.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::ast::{AstNode, BinExpr, BinOp};
diff --git a/crates/ra_assists/src/assists/flip_comma.rs b/crates/ra_assists/src/assists/flip_comma.rs
index 5ee7561bc..e31cc5e7d 100644
--- a/crates/ra_assists/src/assists/flip_comma.rs
+++ b/crates/ra_assists/src/assists/flip_comma.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{algo::non_trivia_sibling, Direction, T};
diff --git a/crates/ra_assists/src/assists/inline_local_variable.rs b/crates/ra_assists/src/assists/inline_local_variable.rs
index eedb29199..9bd64decc 100644
--- a/crates/ra_assists/src/assists/inline_local_variable.rs
+++ b/crates/ra_assists/src/assists/inline_local_variable.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{
    ast::{self, AstNode, AstToken},
diff --git a/crates/ra_assists/src/assists/introduce_variable.rs b/crates/ra_assists/src/assists/introduce_variable.rs
index 470ffe120..43378c4b0 100644
--- a/crates/ra_assists/src/assists/introduce_variable.rs
+++ b/crates/ra_assists/src/assists/introduce_variable.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use format_buf::format;
 use hir::db::HirDatabase;
 use ra_syntax::{
diff --git a/crates/ra_assists/src/assists/merge_match_arms.rs b/crates/ra_assists/src/assists/merge_match_arms.rs
index 3b6a99895..17baa98f9 100644
--- a/crates/ra_assists/src/assists/merge_match_arms.rs
+++ b/crates/ra_assists/src/assists/merge_match_arms.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{Assist, AssistCtx, AssistId, TextRange, TextUnit};
 use hir::db::HirDatabase;
 use ra_syntax::ast::{AstNode, MatchArm};
diff --git a/crates/ra_assists/src/assists/move_bounds.rs b/crates/ra_assists/src/assists/move_bounds.rs
index fd4bdc55c..f791d22b0 100644
--- a/crates/ra_assists/src/assists/move_bounds.rs
+++ b/crates/ra_assists/src/assists/move_bounds.rs
@@ -1,11 +1,13 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{
-    ast::{self, make, AstNode, NameOwner, TypeBoundsOwner},
+    ast::{self, edit, make, AstNode, NameOwner, TypeBoundsOwner},
    SyntaxElement,
    SyntaxKind::*,
 };
-use crate::{ast_editor::AstEditor, Assist, AssistCtx, AssistId};
+use crate::{Assist, AssistCtx, AssistId};
 pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
    let type_param_list = ctx.node_at_offset::<ast::TypeParamList>()?;
@@ -39,14 +41,12 @@ pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>)
                .type_params()
                .filter(|it| it.type_bound_list().is_some())
                .map(|type_param| {
-                    let without_bounds =
+                    let without_bounds = type_param.remove_bounds();
-                        AstEditor::new(type_param.clone()).remove_bounds().ast().clone();
                    (type_param, without_bounds)
                });
-            let mut ast_editor = AstEditor::new(type_param_list.clone());
+            let new_type_param_list = edit::replace_descendants(&type_param_list, new_params);
-            ast_editor.replace_descendants(new_params);
+            edit.replace_ast(type_param_list.clone(), new_type_param_list);
-            ast_editor.into_text_edit(edit.text_edit_builder());
            let where_clause = {
                let predicates = type_param_list.type_params().filter_map(build_predicate);
diff --git a/crates/ra_assists/src/assists/move_guard.rs b/crates/ra_assists/src/assists/move_guard.rs
index 699221e33..51aea6334 100644
--- a/crates/ra_assists/src/assists/move_guard.rs
+++ b/crates/ra_assists/src/assists/move_guard.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{
    ast,
diff --git a/crates/ra_assists/src/assists/raw_string.rs b/crates/ra_assists/src/assists/raw_string.rs
index 200aaa59a..2d2e31e51 100644
--- a/crates/ra_assists/src/assists/raw_string.rs
+++ b/crates/ra_assists/src/assists/raw_string.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::db::HirDatabase;
 use ra_syntax::{ast::AstNode, ast::Literal, TextRange, TextUnit};
 use rustc_lexer;
diff --git a/crates/ra_assists/src/assists/remove_dbg.rs b/crates/ra_assists/src/assists/remove_dbg.rs
index 870133fda..1a7e2b305 100644
--- a/crates/ra_assists/src/assists/remove_dbg.rs
+++ b/crates/ra_assists/src/assists/remove_dbg.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{Assist, AssistCtx, AssistId};
 use hir::db::HirDatabase;
 use ra_syntax::{
diff --git a/crates/ra_assists/src/assists/replace_if_let_with_match.rs b/crates/ra_assists/src/assists/replace_if_let_with_match.rs
index 401835c57..749ff338a 100644
--- a/crates/ra_assists/src/assists/replace_if_let_with_match.rs
+++ b/crates/ra_assists/src/assists/replace_if_let_with_match.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use format_buf::format;
 use hir::db::HirDatabase;
 use ra_fmt::extract_trivial_expression;
diff --git a/crates/ra_assists/src/assists/split_import.rs b/crates/ra_assists/src/assists/split_import.rs
index 2c1edddb9..fe3e64af5 100644
--- a/crates/ra_assists/src/assists/split_import.rs
+++ b/crates/ra_assists/src/assists/split_import.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::iter::successors;
 use hir::db::HirDatabase;
@@ -49,13 +51,13 @@ mod tests {
    fn split_import_works_with_trees() {
        check_assist(
            split_import,
-            "use algo:<|>:visitor::{Visitor, visit}",
+            "use crate:<|>:db::{RootDatabase, FileSymbol}",
-            "use algo::{<|>visitor::{Visitor, visit}}",
+            "use crate::{<|>db::{RootDatabase, FileSymbol}}",
        )
    }
    #[test]
    fn split_import_target() {
-        check_assist_target(split_import, "use algo::<|>visitor::{Visitor, visit}", "::");
+        check_assist_target(split_import, "use crate::<|>db::{RootDatabase, FileSymbol}", "::");
    }
 }
diff --git a/crates/ra_assists/src/ast_editor.rs b/crates/ra_assists/src/ast_editor.rs
deleted file mode 100644
index 2a685f26e..000000000
--- a/crates/ra_assists/src/ast_editor.rs
+++ /dev/null
@@ -1,315 +0,0 @@
-use std::{iter, ops::RangeInclusive};
-use arrayvec::ArrayVec;
-use rustc_hash::FxHashMap;
-use ra_fmt::leading_indent;
-use ra_syntax::{
-    algo,
-    ast::{self, TypeBoundsOwner},
-    AstNode, Direction, InsertPosition, SyntaxElement,
-    SyntaxKind::*,
-    T,
-};
-use ra_text_edit::TextEditBuilder;
-pub struct AstEditor<N: AstNode> {
-    original_ast: N,
-    ast: N,
-}
-impl<N: AstNode> AstEditor<N> {
-    pub fn new(node: N) -> AstEditor<N>
-    where
-        N: Clone,
-    {
-        AstEditor { original_ast: node.clone(), ast: node }
-    }
-    pub fn into_text_edit(self, builder: &mut TextEditBuilder) {
-        for (from, to) in algo::diff(&self.original_ast.syntax(), self.ast().syntax()) {
-            builder.replace(from.text_range(), to.to_string())
-        }
-    }
-    pub fn ast(&self) -> &N {
-        &self.ast
-    }
-    pub fn replace_descendants<T: AstNode>(
-        &mut self,
-        replacement_map: impl Iterator<Item = (T, T)>,
-    ) -> &mut Self {
-        let map = replacement_map
-            .map(|(from, to)| (from.syntax().clone().into(), to.syntax().clone().into()))
-            .collect::<FxHashMap<_, _>>();
-        let new_syntax = algo::replace_descendants(self.ast.syntax(), &map);
-        self.ast = N::cast(new_syntax).unwrap();
-        self
-    }
-    #[must_use]
-    fn insert_children(
-        &self,
-        position: InsertPosition<SyntaxElement>,
-        mut to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> N {
-        let new_syntax = algo::insert_children(self.ast().syntax(), position, &mut to_insert);
-        N::cast(new_syntax).unwrap()
-    }
-    #[must_use]
-    fn replace_children(
-        &self,
-        to_delete: RangeInclusive<SyntaxElement>,
-        mut to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> N {
-        let new_syntax = algo::replace_children(self.ast().syntax(), to_delete, &mut to_insert);
-        N::cast(new_syntax).unwrap()
-    }
-    fn do_make_multiline(&mut self) {
-        let l_curly =
-            match self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{']) {
-                Some(it) => it,
-                None => return,
-            };
-        let sibling = match l_curly.next_sibling_or_token() {
-            Some(it) => it,
-            None => return,
-        };
-        let existing_ws = match sibling.as_token() {
-            None => None,
-            Some(tok) if tok.kind() != WHITESPACE => None,
-            Some(ws) => {
-                if ws.text().contains('\n') {
-                    return;
-                }
-                Some(ws.clone())
-            }
-        };
-        let indent = leading_indent(self.ast().syntax()).unwrap_or("".into());
-        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
-        let to_insert = iter::once(ws.ws().into());
-        self.ast = match existing_ws {
-            None => self.insert_children(InsertPosition::After(l_curly), to_insert),
-            Some(ws) => {
-                self.replace_children(RangeInclusive::new(ws.clone().into(), ws.into()), to_insert)
-            }
-        };
-    }
-}
-impl AstEditor<ast::RecordFieldList> {
-    pub fn append_field(&mut self, field: &ast::RecordField) {
-        self.insert_field(InsertPosition::Last, field)
-    }
-    pub fn insert_field(
-        &mut self,
-        position: InsertPosition<&'_ ast::RecordField>,
-        field: &ast::RecordField,
-    ) {
-        let is_multiline = self.ast().syntax().text().contains_char('\n');
-        let ws;
-        let space = if is_multiline {
-            ws = tokens::WsBuilder::new(&format!(
-                "\n{}    ",
-                leading_indent(self.ast().syntax()).unwrap_or("".into())
-            ));
-            ws.ws()
-        } else {
-            tokens::single_space()
-        };
-        let mut to_insert: ArrayVec<[SyntaxElement; 4]> = ArrayVec::new();
-        to_insert.push(space.into());
-        to_insert.push(field.syntax().clone().into());
-        to_insert.push(tokens::comma().into());
-        macro_rules! after_l_curly {
-            () => {{
-                let anchor = match self.l_curly() {
-                    Some(it) => it,
-                    None => return,
-                };
-                InsertPosition::After(anchor)
-            }};
-        }
-        macro_rules! after_field {
-            ($anchor:expr) => {
-                if let Some(comma) = $anchor
-                    .syntax()
-                    .siblings_with_tokens(Direction::Next)
-                    .find(|it| it.kind() == T![,])
-                {
-                    InsertPosition::After(comma)
-                } else {
-                    to_insert.insert(0, tokens::comma().into());
-                    InsertPosition::After($anchor.syntax().clone().into())
-                }
-            };
-        };
-        let position = match position {
-            InsertPosition::First => after_l_curly!(),
-            InsertPosition::Last => {
-                if !is_multiline {
-                    // don't insert comma before curly
-                    to_insert.pop();
-                }
-                match self.ast().fields().last() {
-                    Some(it) => after_field!(it),
-                    None => after_l_curly!(),
-                }
-            }
-            InsertPosition::Before(anchor) => {
-                InsertPosition::Before(anchor.syntax().clone().into())
-            }
-            InsertPosition::After(anchor) => after_field!(anchor),
-        };
-        self.ast = self.insert_children(position, to_insert.iter().cloned());
-    }
-    fn l_curly(&self) -> Option<SyntaxElement> {
-        self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
-    }
-}
-impl AstEditor<ast::ItemList> {
-    pub fn append_items(&mut self, items: impl Iterator<Item = ast::ImplItem>) {
-        if !self.ast().syntax().text().contains_char('\n') {
-            self.do_make_multiline();
-        }
-        items.for_each(|it| self.append_item(it));
-    }
-    pub fn append_item(&mut self, item: ast::ImplItem) {
-        let (indent, position) = match self.ast().impl_items().last() {
-            Some(it) => (
-                leading_indent(it.syntax()).unwrap_or_default().to_string(),
-                InsertPosition::After(it.syntax().clone().into()),
-            ),
-            None => match self.l_curly() {
-                Some(it) => (
-                    "    ".to_string() + &leading_indent(self.ast().syntax()).unwrap_or_default(),
-                    InsertPosition::After(it),
-                ),
-                None => return,
-            },
-        };
-        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
-        let to_insert: ArrayVec<[SyntaxElement; 2]> =
-            [ws.ws().into(), item.syntax().clone().into()].into();
-        self.ast = self.insert_children(position, to_insert.into_iter());
-    }
-    fn l_curly(&self) -> Option<SyntaxElement> {
-        self.ast().syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
-    }
-}
-impl AstEditor<ast::ImplItem> {
-    pub fn strip_attrs_and_docs(&mut self) {
-        while let Some(start) = self
-            .ast()
-            .syntax()
-            .children_with_tokens()
-            .find(|it| it.kind() == ATTR || it.kind() == COMMENT)
-        {
-            let end = match &start.next_sibling_or_token() {
-                Some(el) if el.kind() == WHITESPACE => el.clone(),
-                Some(_) | None => start.clone(),
-            };
-            self.ast = self.replace_children(RangeInclusive::new(start, end), iter::empty());
-        }
-    }
-}
-impl AstEditor<ast::FnDef> {
-    pub fn set_body(&mut self, body: &ast::Block) {
-        let mut to_insert: ArrayVec<[SyntaxElement; 2]> = ArrayVec::new();
-        let old_body_or_semi: SyntaxElement = if let Some(old_body) = self.ast().body() {
-            old_body.syntax().clone().into()
-        } else if let Some(semi) = self.ast().semicolon_token() {
-            to_insert.push(tokens::single_space().into());
-            semi.into()
-        } else {
-            to_insert.push(tokens::single_space().into());
-            to_insert.push(body.syntax().clone().into());
-            self.ast = self.insert_children(InsertPosition::Last, to_insert.into_iter());
-            return;
-        };
-        to_insert.push(body.syntax().clone().into());
-        let replace_range = RangeInclusive::new(old_body_or_semi.clone(), old_body_or_semi);
-        self.ast = self.replace_children(replace_range, to_insert.into_iter())
-    }
-}
-impl AstEditor<ast::TypeParam> {
-    pub fn remove_bounds(&mut self) -> &mut Self {
-        let colon = match self.ast.colon_token() {
-            Some(it) => it,
-            None => return self,
-        };
-        let end = match self.ast.type_bound_list() {
-            Some(it) => it.syntax().clone().into(),
-            None => colon.clone().into(),
-        };
-        self.ast = self.replace_children(RangeInclusive::new(colon.into(), end), iter::empty());
-        self
-    }
-}
-mod tokens {
-    use once_cell::sync::Lazy;
-    use ra_syntax::{AstNode, Parse, SourceFile, SyntaxKind::*, SyntaxToken, T};
-    static SOURCE_FILE: Lazy<Parse<SourceFile>> = Lazy::new(|| SourceFile::parse(",\n; ;"));
-    pub(crate) fn comma() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == T![,])
-            .unwrap()
-    }
-    pub(crate) fn single_space() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == " ")
-            .unwrap()
-    }
-    #[allow(unused)]
-    pub(crate) fn single_newline() -> SyntaxToken {
-        SOURCE_FILE
-            .tree()
-            .syntax()
-            .descendants_with_tokens()
-            .filter_map(|it| it.into_token())
-            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == "\n")
-            .unwrap()
-    }
-    pub(crate) struct WsBuilder(SourceFile);
-    impl WsBuilder {
-        pub(crate) fn new(text: &str) -> WsBuilder {
-            WsBuilder(SourceFile::parse(text).ok().unwrap())
-        }
-        pub(crate) fn ws(&self) -> SyntaxToken {
-            self.0.syntax().first_child_or_token().unwrap().into_token().unwrap()
-        }
-    }
-}
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 3ca3320f7..d2376c475 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -7,7 +7,6 @@
 mod assist_ctx;
 mod marks;
-pub mod ast_editor;
 use hir::db::HirDatabase;
 use itertools::Itertools;
@@ -93,6 +92,7 @@ mod assists {
    mod add_derive;
    mod add_explicit_type;
    mod add_impl;
+    mod apply_demorgan;
    mod flip_comma;
    mod flip_binexpr;
    mod change_visibility;
@@ -114,6 +114,7 @@ mod assists {
            add_derive::add_derive,
            add_explicit_type::add_explicit_type,
            add_impl::add_impl,
+            apply_demorgan::apply_demorgan,
            change_visibility::change_visibility,
            fill_match_arms::fill_match_arms,
            merge_match_arms::merge_match_arms,
diff --git a/crates/ra_assists/src/marks.rs b/crates/ra_assists/src/marks.rs
index a29f9f658..c20e4db9e 100644
--- a/crates/ra_assists/src/marks.rs
+++ b/crates/ra_assists/src/marks.rs
@@ -1,3 +1,5 @@
+//! See test_utils/src/marks.rs
 test_utils::marks!(
    introduce_var_in_comment_is_not_applicable
    test_introduce_var_expr_stmt
diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index ffc9e16bb..a5fc2a23e 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{collections::HashSet, error::Error, path::Path};
 use rustc_hash::FxHashMap;
@@ -5,7 +7,7 @@ use rustc_hash::FxHashMap;
 use crossbeam_channel::{unbounded, Receiver};
 use ra_db::{CrateGraph, FileId, SourceRootId};
 use ra_ide_api::{AnalysisChange, AnalysisHost, FeatureFlags};
-use ra_project_model::{PackageRoot, ProjectWorkspace};
+use ra_project_model::{get_rustc_cfg_options, PackageRoot, ProjectWorkspace};
 use ra_vfs::{RootEntry, Vfs, VfsChange, VfsTask, Watch};
 use ra_vfs_glob::RustPackageFilterBuilder;
@@ -39,11 +41,17 @@ pub fn load_cargo(root: &Path) -> Result<(AnalysisHost, FxHashMap<SourceRootId,
        sender,
        Watch(false),
    );
-    let (crate_graph, _crate_names) = ws.to_crate_graph(&mut |path: &Path| {
-        let vfs_file = vfs.load(path);
+    // FIXME: cfg options?
-        log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
+    let default_cfg_options =
-        vfs_file.map(vfs_file_to_id)
+        get_rustc_cfg_options().atom("test".into()).atom("debug_assertion".into());
-    });
+    let (crate_graph, _crate_names) =
+        ws.to_crate_graph(&default_cfg_options, &mut |path: &Path| {
+            let vfs_file = vfs.load(path);
+            log::debug!("vfs file {:?} -> {:?}", path, vfs_file);
+            vfs_file.map(vfs_file_to_id)
+        });
    log::debug!("crate graph: {:?}", crate_graph);
    let source_roots = roots
diff --git a/crates/ra_cfg/Cargo.toml b/crates/ra_cfg/Cargo.toml
new file mode 100644
index 000000000..b28affc3a
--- /dev/null
+++ b/crates/ra_cfg/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+edition = "2018"
+name = "ra_cfg"
+version = "0.1.0"
+authors = ["rust-analyzer developers"]
+[dependencies]
+rustc-hash = "1.0.1"
+ra_syntax = { path = "../ra_syntax" }
+tt = { path = "../ra_tt", package = "ra_tt" }
+[dev-dependencies]
+mbe = { path = "../ra_mbe", package = "ra_mbe" }
diff --git a/crates/ra_cfg/src/cfg_expr.rs b/crates/ra_cfg/src/cfg_expr.rs
new file mode 100644
index 000000000..39d71851c
--- /dev/null
+++ b/crates/ra_cfg/src/cfg_expr.rs
@@ -0,0 +1,132 @@
+//! The condition expression used in `#[cfg(..)]` attributes.
+//!
+//! See: https://doc.rust-lang.org/reference/conditional-compilation.html#conditional-compilation
+use std::slice::Iter as SliceIter;
+use ra_syntax::SmolStr;
+use tt::{Leaf, Subtree, TokenTree};
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum CfgExpr {
+    Invalid,
+    Atom(SmolStr),
+    KeyValue { key: SmolStr, value: SmolStr },
+    All(Vec<CfgExpr>),
+    Any(Vec<CfgExpr>),
+    Not(Box<CfgExpr>),
+}
+impl CfgExpr {
+    /// Fold the cfg by querying all basic `Atom` and `KeyValue` predicates.
+    pub fn fold(&self, query: &dyn Fn(&SmolStr, Option<&SmolStr>) -> bool) -> Option<bool> {
+        match self {
+            CfgExpr::Invalid => None,
+            CfgExpr::Atom(name) => Some(query(name, None)),
+            CfgExpr::KeyValue { key, value } => Some(query(key, Some(value))),
+            CfgExpr::All(preds) => {
+                preds.iter().try_fold(true, |s, pred| Some(s && pred.fold(query)?))
+            }
+            CfgExpr::Any(preds) => {
+                preds.iter().try_fold(false, |s, pred| Some(s || pred.fold(query)?))
+            }
+            CfgExpr::Not(pred) => pred.fold(query).map(|s| !s),
+        }
+    }
+}
+pub fn parse_cfg(tt: &Subtree) -> CfgExpr {
+    next_cfg_expr(&mut tt.token_trees.iter()).unwrap_or(CfgExpr::Invalid)
+}
+fn next_cfg_expr(it: &mut SliceIter<tt::TokenTree>) -> Option<CfgExpr> {
+    let name = match it.next() {
+        None => return None,
+        Some(TokenTree::Leaf(Leaf::Ident(ident))) => ident.text.clone(),
+        Some(_) => return Some(CfgExpr::Invalid),
+    };
+    // Peek
+    let ret = match it.as_slice().first() {
+        Some(TokenTree::Leaf(Leaf::Punct(punct))) if punct.char == '=' => {
+            match it.as_slice().get(1) {
+                Some(TokenTree::Leaf(Leaf::Literal(literal))) => {
+                    it.next();
+                    it.next();
+                    // FIXME: escape? raw string?
+                    let value =
+                        SmolStr::new(literal.text.trim_start_matches('"').trim_end_matches('"'));
+                    CfgExpr::KeyValue { key: name, value }
+                }
+                _ => return Some(CfgExpr::Invalid),
+            }
+        }
+        Some(TokenTree::Subtree(subtree)) => {
+            it.next();
+            let mut sub_it = subtree.token_trees.iter();
+            let mut subs = std::iter::from_fn(|| next_cfg_expr(&mut sub_it)).collect();
+            match name.as_str() {
+                "all" => CfgExpr::All(subs),
+                "any" => CfgExpr::Any(subs),
+                "not" => CfgExpr::Not(Box::new(subs.pop().unwrap_or(CfgExpr::Invalid))),
+                _ => CfgExpr::Invalid,
+            }
+        }
+        _ => CfgExpr::Atom(name),
+    };
+    // Eat comma separator
+    if let Some(TokenTree::Leaf(Leaf::Punct(punct))) = it.as_slice().first() {
+        if punct.char == ',' {
+            it.next();
+        }
+    }
+    Some(ret)
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use mbe::ast_to_token_tree;
+    use ra_syntax::ast::{self, AstNode};
+    fn assert_parse_result(input: &str, expected: CfgExpr) {
+        let source_file = ast::SourceFile::parse(input).ok().unwrap();
+        let tt = source_file.syntax().descendants().find_map(ast::TokenTree::cast).unwrap();
+        let (tt, _) = ast_to_token_tree(&tt).unwrap();
+        assert_eq!(parse_cfg(&tt), expected);
+    }
+    #[test]
+    fn test_cfg_expr_parser() {
+        assert_parse_result("#![cfg(foo)]", CfgExpr::Atom("foo".into()));
+        assert_parse_result("#![cfg(foo,)]", CfgExpr::Atom("foo".into()));
+        assert_parse_result(
+            "#![cfg(not(foo))]",
+            CfgExpr::Not(Box::new(CfgExpr::Atom("foo".into()))),
+        );
+        assert_parse_result("#![cfg(foo(bar))]", CfgExpr::Invalid);
+        // Only take the first
+        assert_parse_result(r#"#![cfg(foo, bar = "baz")]"#, CfgExpr::Atom("foo".into()));
+        assert_parse_result(
+            r#"#![cfg(all(foo, bar = "baz"))]"#,
+            CfgExpr::All(vec![
+                CfgExpr::Atom("foo".into()),
+                CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
+            ]),
+        );
+        assert_parse_result(
+            r#"#![cfg(any(not(), all(), , bar = "baz",))]"#,
+            CfgExpr::Any(vec![
+                CfgExpr::Not(Box::new(CfgExpr::Invalid)),
+                CfgExpr::All(vec![]),
+                CfgExpr::Invalid,
+                CfgExpr::KeyValue { key: "bar".into(), value: "baz".into() },
+            ]),
+        );
+    }
+}
diff --git a/crates/ra_cfg/src/lib.rs b/crates/ra_cfg/src/lib.rs
new file mode 100644
index 000000000..e1c92fbba
--- /dev/null
+++ b/crates/ra_cfg/src/lib.rs
@@ -0,0 +1,61 @@
+//! ra_cfg defines conditional compiling options, `cfg` attibute parser and evaluator
+use std::iter::IntoIterator;
+use ra_syntax::SmolStr;
+use rustc_hash::FxHashSet;
+mod cfg_expr;
+pub use cfg_expr::{parse_cfg, CfgExpr};
+/// Configuration options used for conditional compilition on items with `cfg` attributes.
+/// We have two kind of options in different namespaces: atomic options like `unix`, and
+/// key-value options like `target_arch="x86"`.
+///
+/// Note that for key-value options, one key can have multiple values (but not none).
+/// `feature` is an example. We have both `feature="foo"` and `feature="bar"` if features
+/// `foo` and `bar` are both enabled. And here, we store key-value options as a set of tuple
+/// of key and value in `key_values`.
+///
+/// See: https://doc.rust-lang.org/reference/conditional-compilation.html#set-configuration-options
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct CfgOptions {
+    atoms: FxHashSet<SmolStr>,
+    key_values: FxHashSet<(SmolStr, SmolStr)>,
+}
+impl CfgOptions {
+    pub fn check(&self, cfg: &CfgExpr) -> Option<bool> {
+        cfg.fold(&|key, value| match value {
+            None => self.atoms.contains(key),
+            Some(value) => self.key_values.contains(&(key.clone(), value.clone())),
+        })
+    }
+    pub fn is_cfg_enabled(&self, attr: &tt::Subtree) -> Option<bool> {
+        self.check(&parse_cfg(attr))
+    }
+    pub fn atom(mut self, name: SmolStr) -> CfgOptions {
+        self.atoms.insert(name);
+        self
+    }
+    pub fn key_value(mut self, key: SmolStr, value: SmolStr) -> CfgOptions {
+        self.key_values.insert((key, value));
+        self
+    }
+    /// Shortcut to set features
+    pub fn features(mut self, iter: impl IntoIterator<Item = SmolStr>) -> CfgOptions {
+        for feat in iter {
+            self = self.key_value("feature".into(), feat);
+        }
+        self
+    }
+    pub fn remove_atom(mut self, name: &SmolStr) -> CfgOptions {
+        self.atoms.remove(name);
+        self
+    }
+}
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index d42ac3ad4..67e727a88 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -6,7 +6,7 @@ authors = ["rust-analyzer developers"]
 publish = false
 [dependencies]
-pico-args = "0.2.0"
+pico-args = "0.3.0"
 flexi_logger = "0.14.0"
 indicatif = "0.11.0"
diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 01b96ec58..727f1e62b 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    path::{Path, PathBuf},
    sync::Arc,
diff --git a/crates/ra_cli/src/analysis_stats.rs b/crates/ra_cli/src/analysis_stats.rs
index 6b1e44a2c..a8a110bd9 100644
--- a/crates/ra_cli/src/analysis_stats.rs
+++ b/crates/ra_cli/src/analysis_stats.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{collections::HashSet, fmt::Write, path::Path, time::Instant};
 use ra_db::SourceDatabase;
diff --git a/crates/ra_cli/src/help.rs b/crates/ra_cli/src/help.rs
index 2a74b8733..d3c4c7d0b 100644
--- a/crates/ra_cli/src/help.rs
+++ b/crates/ra_cli/src/help.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 pub const GLOBAL_HELP: &str = "ra-cli
 USAGE:
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index 8b91ba3e9..2405eb4f4 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod analysis_stats;
 mod analysis_bench;
 mod help;
@@ -93,7 +95,7 @@ fn main() -> Result<()> {
                (true, true) => Err("Invalid flags: -q conflicts with -v")?,
            };
            let memory_usage = matches.contains("--memory-usage");
-            let only: Option<String> = matches.value_from_str(["-o", "--only"])?;
+            let only: Option<String> = matches.opt_value_from_str(["-o", "--only"])?;
            let path = {
                let mut trailing = matches.free()?;
                if trailing.len() != 1 {
@@ -115,9 +117,9 @@ fn main() -> Result<()> {
                return Ok(());
            }
            let verbose = matches.contains(["-v", "--verbose"]);
-            let path: String = matches.value_from_str("--path")?.unwrap_or_default();
+            let path: String = matches.opt_value_from_str("--path")?.unwrap_or_default();
-            let highlight_path = matches.value_from_str("--highlight")?;
+            let highlight_path = matches.opt_value_from_str("--highlight")?;
-            let complete_path = matches.value_from_str("--complete")?;
+            let complete_path = matches.opt_value_from_str("--complete")?;
            if highlight_path.is_some() && complete_path.is_some() {
                panic!("either --highlight or --complete must be set, not both")
            }
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 2fac07bc5..c141f1a88 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -10,4 +10,5 @@ relative-path = "0.4.0"
 rustc-hash = "1.0"
 ra_syntax = { path = "../ra_syntax" }
+ra_cfg = { path = "../ra_cfg" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index a1ace61b6..23148096c 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -1,13 +1,15 @@
-/// This module specifies the input to rust-analyzer. In some sense, this is
+//! This module specifies the input to rust-analyzer. In some sense, this is
-/// **the** most important module, because all other fancy stuff is strictly
+//! **the** most important module, because all other fancy stuff is strictly
-/// derived from this input.
+//! derived from this input.
-///
+//!
-/// Note that neither this module, nor any other part of the analyzer's core do
+//! Note that neither this module, nor any other part of the analyzer's core do
-/// actual IO. See `vfs` and `project_model` in the `ra_lsp_server` crate for how
+//! actual IO. See `vfs` and `project_model` in the `ra_lsp_server` crate for how
-/// actual IO is done and lowered to input.
+//! actual IO is done and lowered to input.
 use relative_path::{RelativePath, RelativePathBuf};
 use rustc_hash::FxHashMap;
+use ra_cfg::CfgOptions;
 use ra_syntax::SmolStr;
 use rustc_hash::FxHashSet;
@@ -108,11 +110,12 @@ struct CrateData {
    file_id: FileId,
    edition: Edition,
    dependencies: Vec<Dependency>,
+    cfg_options: CfgOptions,
 }
 impl CrateData {
-    fn new(file_id: FileId, edition: Edition) -> CrateData {
+    fn new(file_id: FileId, edition: Edition, cfg_options: CfgOptions) -> CrateData {
-        CrateData { file_id, edition, dependencies: Vec::new() }
+        CrateData { file_id, edition, dependencies: Vec::new(), cfg_options }
    }
    fn add_dep(&mut self, name: SmolStr, crate_id: CrateId) {
@@ -133,13 +136,22 @@ impl Dependency {
 }
 impl CrateGraph {
-    pub fn add_crate_root(&mut self, file_id: FileId, edition: Edition) -> CrateId {
+    pub fn add_crate_root(
+        &mut self,
+        file_id: FileId,
+        edition: Edition,
+        cfg_options: CfgOptions,
+    ) -> CrateId {
        let crate_id = CrateId(self.arena.len() as u32);
-        let prev = self.arena.insert(crate_id, CrateData::new(file_id, edition));
+        let prev = self.arena.insert(crate_id, CrateData::new(file_id, edition, cfg_options));
        assert!(prev.is_none());
        crate_id
    }
+    pub fn cfg_options(&self, crate_id: CrateId) -> &CfgOptions {
+        &self.arena[&crate_id].cfg_options
+    }
    pub fn add_dep(
        &mut self,
        from: CrateId,
@@ -220,14 +232,14 @@ impl CrateGraph {
 #[cfg(test)]
 mod tests {
-    use super::{CrateGraph, Edition::Edition2018, FileId, SmolStr};
+    use super::{CfgOptions, CrateGraph, Edition::Edition2018, FileId, SmolStr};
    #[test]
    fn it_should_panic_because_of_cycle_dependencies() {
        let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default());
-        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default());
-        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default());
        assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
        assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
        assert!(graph.add_dep(crate3, SmolStr::new("crate1"), crate1).is_err());
@@ -236,9 +248,9 @@ mod tests {
    #[test]
    fn it_works() {
        let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018, CfgOptions::default());
-        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018, CfgOptions::default());
-        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018, CfgOptions::default());
        assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
        assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
    }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index c54791b7a..603daed37 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -32,11 +32,10 @@ pub trait CheckCanceled {
    fn catch_canceled<F, T>(&self, f: F) -> Result<T, Canceled>
    where
-        Self: Sized,
+        Self: Sized + panic::RefUnwindSafe,
        F: FnOnce(&Self) -> T + panic::UnwindSafe,
    {
-        let this = panic::AssertUnwindSafe(self);
+        panic::catch_unwind(|| f(self)).map_err(|err| match err.downcast::<Canceled>() {
-        panic::catch_unwind(|| f(*this)).map_err(|err| match err.downcast::<Canceled>() {
            Ok(canceled) => *canceled,
            Err(payload) => panic::resume_unwind(payload),
        })
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index d9bed4dda..cc117f84d 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -15,6 +15,7 @@ once_cell = "1.0.1"
 ra_syntax = { path = "../ra_syntax" }
 ra_arena = { path = "../ra_arena" }
+ra_cfg = { path = "../ra_cfg" }
 ra_db = { path = "../ra_db" }
 mbe = { path = "../ra_mbe", package = "ra_mbe" }
 tt = { path = "../ra_tt", package = "ra_tt" }
diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index fbb4ff4d8..99d286215 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -133,7 +133,7 @@ impl VariantData {
                    .fields()
                    .enumerate()
                    .map(|(i, fd)| StructFieldData {
-                        name: Name::tuple_field_name(i),
+                        name: Name::new_tuple_field(i),
                        type_ref: TypeRef::from_ast_opt(fd.type_ref()),
                    })
                    .collect();
diff --git a/crates/ra_hir/src/attr.rs b/crates/ra_hir/src/attr.rs
new file mode 100644
index 000000000..f67e80bfd
--- /dev/null
+++ b/crates/ra_hir/src/attr.rs
@@ -0,0 +1,80 @@
+//! A higher level attributes based on TokenTree, with also some shortcuts.
+use std::sync::Arc;
+use mbe::ast_to_token_tree;
+use ra_cfg::CfgOptions;
+use ra_syntax::{
+    ast::{self, AstNode, AttrsOwner},
+    SmolStr,
+};
+use tt::Subtree;
+use crate::{db::AstDatabase, path::Path, HirFileId, Source};
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct Attr {
+    pub(crate) path: Path,
+    pub(crate) input: Option<AttrInput>,
+}
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AttrInput {
+    Literal(SmolStr),
+    TokenTree(Subtree),
+}
+impl Attr {
+    pub(crate) fn from_src(
+        Source { file_id, ast }: Source<ast::Attr>,
+        db: &impl AstDatabase,
+    ) -> Option<Attr> {
+        let path = Path::from_src(Source { file_id, ast: ast.path()? }, db)?;
+        let input = match ast.input() {
+            None => None,
+            Some(ast::AttrInput::Literal(lit)) => {
+                // FIXME: escape? raw string?
+                let value = lit.syntax().first_token()?.text().trim_matches('"').into();
+                Some(AttrInput::Literal(value))
+            }
+            Some(ast::AttrInput::TokenTree(tt)) => {
+                Some(AttrInput::TokenTree(ast_to_token_tree(&tt)?.0))
+            }
+        };
+        Some(Attr { path, input })
+    }
+    pub(crate) fn from_attrs_owner(
+        file_id: HirFileId,
+        owner: &dyn AttrsOwner,
+        db: &impl AstDatabase,
+    ) -> Option<Arc<[Attr]>> {
+        let mut attrs = owner.attrs().peekable();
+        if attrs.peek().is_none() {
+            // Avoid heap allocation
+            return None;
+        }
+        Some(attrs.flat_map(|ast| Attr::from_src(Source { file_id, ast }, db)).collect())
+    }
+    pub(crate) fn is_simple_atom(&self, name: &str) -> bool {
+        // FIXME: Avoid cloning
+        self.path.as_ident().map_or(false, |s| s.to_string() == name)
+    }
+    pub(crate) fn as_cfg(&self) -> Option<&Subtree> {
+        if self.is_simple_atom("cfg") {
+            match &self.input {
+                Some(AttrInput::TokenTree(subtree)) => Some(subtree),
+                _ => None,
+            }
+        } else {
+            None
+        }
+    }
+    pub(crate) fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> Option<bool> {
+        cfg_options.is_cfg_enabled(self.as_cfg()?)
+    }
+}
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 20413cb3d..e3a7e8e3c 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 pub(crate) mod src;
 pub(crate) mod docs;
@@ -339,10 +341,14 @@ pub struct Struct {
 }
 impl Struct {
-    pub fn module(self, db: &impl HirDatabase) -> Module {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
        self.id.module(db)
    }
+    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
+        self.module(db).krate(db)
+    }
    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
        db.struct_data(self).name.clone()
    }
@@ -423,10 +429,14 @@ pub struct Enum {
 }
 impl Enum {
-    pub fn module(self, db: &impl HirDatabase) -> Module {
+    pub fn module(self, db: &impl DefDatabase) -> Module {
        self.id.module(db)
    }
+    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
+        self.module(db).krate(db)
+    }
    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
        db.enum_data(self).name.clone()
    }
@@ -514,7 +524,7 @@ impl Adt {
        }
    }
-    pub(crate) fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
+    pub fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
        match self {
            Adt::Struct(s) => s.module(db),
            Adt::Union(s) => s.module(db),
diff --git a/crates/ra_hir/src/code_model/docs.rs b/crates/ra_hir/src/code_model/docs.rs
index 99edc5814..9675e397f 100644
--- a/crates/ra_hir/src/code_model/docs.rs
+++ b/crates/ra_hir/src/code_model/docs.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
 use ra_syntax::ast;
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index c0cb27b47..fdae26906 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_syntax::{
    ast::{self, AstNode},
    SyntaxNode,
@@ -119,7 +121,7 @@ impl HasSource for TypeAlias {
 impl HasSource for MacroDef {
    type Ast = ast::MacroCall;
    fn source(self, db: &(impl DefDatabase + AstDatabase)) -> Source<ast::MacroCall> {
-        Source { file_id: self.id.0.file_id(), ast: self.id.0.to_node(db) }
+        Source { file_id: self.id.ast_id.file_id(), ast: self.id.ast_id.to_node(db) }
    }
 }
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index deed1c62f..73d7d6fb6 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
 use ra_db::{salsa, SourceDatabase};
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index 60da33695..9acdaf8ed 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{any::Any, fmt};
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr, TextRange};
diff --git a/crates/ra_hir/src/either.rs b/crates/ra_hir/src/either.rs
index 439e6ec87..83583ef8b 100644
--- a/crates/ra_hir/src/either.rs
+++ b/crates/ra_hir/src/either.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum Either<A, B> {
    A(A),
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index b1bec2a68..d238741ba 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 pub(crate) mod lower;
 pub(crate) mod scope;
 pub(crate) mod validation;
diff --git a/crates/ra_hir/src/expr/lower.rs b/crates/ra_hir/src/expr/lower.rs
index 61535d24f..50ea429ea 100644
--- a/crates/ra_hir/src/expr/lower.rs
+++ b/crates/ra_hir/src/expr/lower.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_arena::Arena;
 use ra_syntax::{
    ast::{
@@ -272,8 +274,11 @@ where
                self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
            }
            ast::Expr::PathExpr(e) => {
-                let path =
+                let path = e
-                    e.path().and_then(Path::from_ast).map(Expr::Path).unwrap_or(Expr::Missing);
+                    .path()
+                    .and_then(|path| self.parse_path(path))
+                    .map(Expr::Path)
+                    .unwrap_or(Expr::Missing);
                self.alloc_expr(path, syntax_ptr)
            }
            ast::Expr::ContinueExpr(_e) => {
@@ -295,7 +300,7 @@ where
                self.alloc_expr(Expr::Return { expr }, syntax_ptr)
            }
            ast::Expr::RecordLit(e) => {
-                let path = e.path().and_then(Path::from_ast);
+                let path = e.path().and_then(|path| self.parse_path(path));
                let mut field_ptrs = Vec::new();
                let record_lit = if let Some(nfl) = e.record_field_list() {
                    let fields = nfl
@@ -459,7 +464,7 @@ where
                    .ast_id(&e)
                    .with_file_id(self.current_file_id);
-                if let Some(path) = e.path().and_then(Path::from_ast) {
+                if let Some(path) = e.path().and_then(|path| self.parse_path(path)) {
                    if let Some(def) = self.resolver.resolve_path_as_macro(self.db, &path) {
                        let call_id = MacroCallLoc { def: def.id, ast_id }.id(self.db);
                        let file_id = call_id.as_file(MacroFileKind::Expr);
@@ -529,7 +534,7 @@ where
                Pat::Bind { name, mode: annotation, subpat }
            }
            ast::Pat::TupleStructPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                let args = p.args().map(|p| self.collect_pat(p)).collect();
                Pat::TupleStruct { path, args }
            }
@@ -539,7 +544,7 @@ where
                Pat::Ref { pat, mutability }
            }
            ast::Pat::PathPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                path.map(Pat::Path).unwrap_or(Pat::Missing)
            }
            ast::Pat::TuplePat(p) => {
@@ -548,7 +553,7 @@ where
            }
            ast::Pat::PlaceholderPat(_) => Pat::Wild,
            ast::Pat::RecordPat(p) => {
-                let path = p.path().and_then(Path::from_ast);
+                let path = p.path().and_then(|path| self.parse_path(path));
                let record_field_pat_list =
                    p.record_field_pat_list().expect("every struct should have a field list");
                let mut fields: Vec<_> = record_field_pat_list
@@ -589,6 +594,10 @@ where
            self.missing_pat()
        }
    }
+    fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
+        Path::from_src(Source { ast: path, file_id: self.current_file_id }, self.db)
+    }
 }
 impl From<ast::BinOp> for BinaryOp {
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index de0983a7e..5496822e7 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
 use ra_arena::{impl_arena_id, Arena, RawId};
diff --git a/crates/ra_hir/src/expr/validation.rs b/crates/ra_hir/src/expr/validation.rs
index f06e5ec07..1aa853c3e 100644
--- a/crates/ra_hir/src/expr/validation.rs
+++ b/crates/ra_hir/src/expr/validation.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
 use ra_syntax::ast;
diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index 7b6d9b240..a012f33f7 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::{FileId, FilePosition};
 use ra_syntax::{
    algo::find_node_at_offset,
diff --git a/crates/ra_hir/src/generics.rs b/crates/ra_hir/src/generics.rs
index 6865d34ba..4ce7551c3 100644
--- a/crates/ra_hir/src/generics.rs
+++ b/crates/ra_hir/src/generics.rs
@@ -132,6 +132,7 @@ impl GenericParams {
    fn fill_params(&mut self, params: ast::TypeParamList, start: u32) {
        for (idx, type_param) in params.type_params().enumerate() {
            let name = type_param.name().map_or_else(Name::missing, |it| it.as_name());
+            // FIXME: Use `Path::from_src`
            let default = type_param.default_type().and_then(|t| t.path()).and_then(Path::from_ast);
            let param = GenericParam { idx: idx as u32 + start, name: name.clone(), default };
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 9ea4e695d..a3b65cc79 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    hash::{Hash, Hasher},
    sync::Arc,
@@ -10,7 +12,7 @@ use ra_syntax::{ast, AstNode, Parse, SyntaxNode};
 use crate::{
    db::{AstDatabase, DefDatabase, InternDatabase},
-    AstId, FileAstId, Module, Source,
+    AstId, Crate, FileAstId, Module, Source,
 };
 /// hir makes heavy use of ids: integer (u32) handlers to various things. You
@@ -58,6 +60,17 @@ impl HirFileId {
        }
    }
+    /// Get the crate which the macro lives in, if it is a macro file.
+    pub(crate) fn macro_crate(self, db: &impl AstDatabase) -> Option<Crate> {
+        match self.0 {
+            HirFileIdRepr::File(_) => None,
+            HirFileIdRepr::Macro(macro_file) => {
+                let loc = macro_file.macro_call_id.loc(db);
+                Some(loc.def.krate)
+            }
+        }
+    }
    pub(crate) fn parse_or_expand_query(
        db: &impl AstDatabase,
        file_id: HirFileId,
@@ -121,10 +134,13 @@ impl From<FileId> for HirFileId {
 }
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct MacroDefId(pub(crate) AstId<ast::MacroCall>);
+pub struct MacroDefId {
+    pub(crate) ast_id: AstId<ast::MacroCall>,
+    pub(crate) krate: Crate,
+}
 pub(crate) fn macro_def_query(db: &impl AstDatabase, id: MacroDefId) -> Option<Arc<MacroRules>> {
-    let macro_call = id.0.to_node(db);
+    let macro_call = id.ast_id.to_node(db);
    let arg = macro_call.token_tree()?;
    let (tt, _) = mbe::ast_to_token_tree(&arg).or_else(|| {
        log::warn!("fail on macro_def to token tree: {:#?}", arg);
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index d830202bd..55dfc393b 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -1,13 +1,17 @@
+//! FIXME: write short doc here
 use rustc_hash::FxHashMap;
 use std::sync::Arc;
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
+use ra_cfg::CfgOptions;
 use ra_syntax::{
    ast::{self, AstNode},
    AstPtr,
 };
 use crate::{
+    attr::Attr,
    code_model::{Module, ModuleSource},
    db::{AstDatabase, DefDatabase, HirDatabase},
    generics::HasGenericParams,
@@ -174,6 +178,7 @@ pub struct ModuleImplBlocks {
 impl ModuleImplBlocks {
    fn collect(
        db: &(impl DefDatabase + AstDatabase),
+        cfg_options: &CfgOptions,
        module: Module,
        source_map: &mut ImplSourceMap,
    ) -> Self {
@@ -186,11 +191,11 @@ impl ModuleImplBlocks {
        let src = m.module.definition_source(db);
        match &src.ast {
            ModuleSource::SourceFile(node) => {
-                m.collect_from_item_owner(db, source_map, node, src.file_id)
+                m.collect_from_item_owner(db, cfg_options, source_map, node, src.file_id)
            }
            ModuleSource::Module(node) => {
                let item_list = node.item_list().expect("inline module should have item list");
-                m.collect_from_item_owner(db, source_map, &item_list, src.file_id)
+                m.collect_from_item_owner(db, cfg_options, source_map, &item_list, src.file_id)
            }
        };
        m
@@ -199,6 +204,7 @@ impl ModuleImplBlocks {
    fn collect_from_item_owner(
        &mut self,
        db: &(impl DefDatabase + AstDatabase),
+        cfg_options: &CfgOptions,
        source_map: &mut ImplSourceMap,
        owner: &dyn ast::ModuleItemOwner,
        file_id: HirFileId,
@@ -206,6 +212,13 @@ impl ModuleImplBlocks {
        for item in owner.items_with_macros() {
            match item {
                ast::ItemOrMacro::Item(ast::ModuleItem::ImplBlock(impl_block_ast)) => {
+                    let attrs = Attr::from_attrs_owner(file_id, &impl_block_ast, db);
+                    if attrs.map_or(false, |attrs| {
+                        attrs.iter().any(|attr| attr.is_cfg_enabled(cfg_options) == Some(false))
+                    }) {
+                        continue;
+                    }
                    let impl_block = ImplData::from_ast(db, file_id, self.module, &impl_block_ast);
                    let id = self.impls.alloc(impl_block);
                    for &impl_item in &self.impls[id].items {
@@ -216,9 +229,19 @@ impl ModuleImplBlocks {
                }
                ast::ItemOrMacro::Item(_) => (),
                ast::ItemOrMacro::Macro(macro_call) => {
+                    let attrs = Attr::from_attrs_owner(file_id, &macro_call, db);
+                    if attrs.map_or(false, |attrs| {
+                        attrs.iter().any(|attr| attr.is_cfg_enabled(cfg_options) == Some(false))
+                    }) {
+                        continue;
+                    }
                    //FIXME: we should really cut down on the boilerplate required to process a macro
                    let ast_id = db.ast_id_map(file_id).ast_id(&macro_call).with_file_id(file_id);
-                    if let Some(path) = macro_call.path().and_then(Path::from_ast) {
+                    if let Some(path) = macro_call
+                        .path()
+                        .and_then(|path| Path::from_src(Source { ast: path, file_id }, db))
+                    {
                        if let Some(def) = self.module.resolver(db).resolve_path_as_macro(db, &path)
                        {
                            let call_id = MacroCallLoc { def: def.id, ast_id }.id(db);
@@ -226,7 +249,13 @@ impl ModuleImplBlocks {
                            if let Some(item_list) =
                                db.parse_or_expand(file_id).and_then(ast::MacroItems::cast)
                            {
-                                self.collect_from_item_owner(db, source_map, &item_list, file_id)
+                                self.collect_from_item_owner(
+                                    db,
+                                    cfg_options,
+                                    source_map,
+                                    &item_list,
+                                    file_id,
+                                )
                            }
                        }
                    }
@@ -241,8 +270,10 @@ pub(crate) fn impls_in_module_with_source_map_query(
    module: Module,
 ) -> (Arc<ModuleImplBlocks>, Arc<ImplSourceMap>) {
    let mut source_map = ImplSourceMap::default();
+    let crate_graph = db.crate_graph();
+    let cfg_options = crate_graph.cfg_options(module.krate.crate_id());
-    let result = ModuleImplBlocks::collect(db, module, &mut source_map);
+    let result = ModuleImplBlocks::collect(db, cfg_options, module, &mut source_map);
    (Arc::new(result), Arc::new(source_map))
 }
diff --git a/crates/ra_hir/src/lang_item.rs b/crates/ra_hir/src/lang_item.rs
index bcce314d8..6c4e8ffbd 100644
--- a/crates/ra_hir/src/lang_item.rs
+++ b/crates/ra_hir/src/lang_item.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use rustc_hash::FxHashMap;
 use std::sync::Arc;
@@ -151,7 +153,7 @@ impl LangItems {
 fn lang_item_name<T: AttrsOwner>(node: &T) -> Option<SmolStr> {
    node.attrs()
-        .filter_map(|a| a.as_key_value())
+        .filter_map(|a| a.as_simple_key_value())
        .filter(|(key, _)| key == "lang")
        .map(|(_, val)| val)
        .nth(0)
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index a9de9fb6b..4340e9d34 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -1,5 +1,3 @@
-#![recursion_limit = "512"]
 //! HIR (previously known as descriptors) provides a high-level object oriented
 //! access to Rust code.
 //!
@@ -7,6 +5,8 @@
 //! to a particular crate instance. That is, it has cfg flags and features
 //! applied. So, the relation between syntax and HIR is many-to-one.
+#![recursion_limit = "512"]
 macro_rules! impl_froms {
    ($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
        $(
@@ -44,6 +44,7 @@ mod traits;
 mod type_alias;
 mod type_ref;
 mod ty;
+mod attr;
 mod impl_block;
 mod expr;
 mod lang_item;
diff --git a/crates/ra_hir/src/marks.rs b/crates/ra_hir/src/marks.rs
index b2111be05..79af24b20 100644
--- a/crates/ra_hir/src/marks.rs
+++ b/crates/ra_hir/src/marks.rs
@@ -1,3 +1,5 @@
+//! See test_utils/src/marks.rs
 test_utils::marks!(
    bogus_paths
    name_res_works_for_broken_modules
@@ -9,9 +11,10 @@ test_utils::marks!(
    glob_across_crates
    std_prelude
    match_ergonomics_ref
-    trait_resolution_on_fn_type
    infer_while_let
    macro_rules_from_other_crates_are_visible_with_macro_use
    prelude_is_macro_use
    coerce_merge_fail_fallback
+    macro_dollar_crate_self
+    macro_dollar_crate_other
 );
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index cb405091e..f750986b8 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -1,6 +1,9 @@
+//! FIXME: write short doc here
 use std::{panic, sync::Arc};
 use parking_lot::Mutex;
+use ra_cfg::CfgOptions;
 use ra_db::{
    salsa, CrateGraph, CrateId, Edition, FileId, FilePosition, SourceDatabase, SourceRoot,
    SourceRootId,
@@ -72,13 +75,13 @@ impl MockDatabase {
    pub fn set_crate_graph_from_fixture(&mut self, graph: CrateGraphFixture) {
        let mut ids = FxHashMap::default();
        let mut crate_graph = CrateGraph::default();
-        for (crate_name, (crate_root, edition, _)) in graph.0.iter() {
+        for (crate_name, (crate_root, edition, cfg_options, _)) in graph.0.iter() {
            let crate_root = self.file_id_of(&crate_root);
-            let crate_id = crate_graph.add_crate_root(crate_root, *edition);
+            let crate_id = crate_graph.add_crate_root(crate_root, *edition, cfg_options.clone());
            Arc::make_mut(&mut self.crate_names).insert(crate_id, crate_name.clone());
            ids.insert(crate_name, crate_id);
        }
-        for (crate_name, (_, _, deps)) in graph.0.iter() {
+        for (crate_name, (_, _, _, deps)) in graph.0.iter() {
            let from = ids[crate_name];
            for dep in deps {
                let to = ids[dep];
@@ -182,7 +185,7 @@ impl MockDatabase {
        if is_crate_root {
            let mut crate_graph = CrateGraph::default();
-            crate_graph.add_crate_root(file_id, Edition::Edition2018);
+            crate_graph.add_crate_root(file_id, Edition::Edition2018, CfgOptions::default());
            self.set_crate_graph(Arc::new(crate_graph));
        }
        file_id
@@ -266,19 +269,27 @@ impl MockDatabase {
 }
 #[derive(Default)]
-pub struct CrateGraphFixture(pub Vec<(String, (String, Edition, Vec<String>))>);
+pub struct CrateGraphFixture(pub Vec<(String, (String, Edition, CfgOptions, Vec<String>))>);
 #[macro_export]
 macro_rules! crate_graph {
-    ($($crate_name:literal: ($crate_path:literal, $($edition:literal,)? [$($dep:literal),*]),)*) => {{
+    ($(
+        $crate_name:literal: (
+            $crate_path:literal,
+            $($edition:literal,)?
+            [$($dep:literal),*]
+            $(,$cfg:expr)?
+        ),
+    )*) => {{
        let mut res = $crate::mock::CrateGraphFixture::default();
        $(
            #[allow(unused_mut, unused_assignments)]
            let mut edition = ra_db::Edition::Edition2018;
            $(edition = ra_db::Edition::from_string($edition);)?
+            let cfg_options = { ::ra_cfg::CfgOptions::default() $(; $cfg)? };
            res.0.push((
                $crate_name.to_string(),
-                ($crate_path.to_string(), edition, vec![$($dep.to_string()),*])
+                ($crate_path.to_string(), edition, cfg_options, vec![$($dep.to_string()),*])
            ));
        )*
        res
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 1bf993ffb..1e0b8c350 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 use ra_syntax::{ast, SmolStr};
@@ -5,20 +7,21 @@ use ra_syntax::{ast, SmolStr};
 /// `Name` is a wrapper around string, which is used in hir for both references
 /// and declarations. In theory, names should also carry hygiene info, but we are
 /// not there yet!
-#[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-pub struct Name {
+pub struct Name(Repr);
-    text: SmolStr,
-}
-impl fmt::Display for Name {
+#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+enum Repr {
-        fmt::Display::fmt(&self.text, f)
+    Text(SmolStr),
-    }
+    TupleField(usize),
 }
-impl fmt::Debug for Name {
+impl fmt::Display for Name {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Debug::fmt(&self.text, f)
+        match &self.0 {
+            Repr::Text(text) => fmt::Display::fmt(&text, f),
+            Repr::TupleField(idx) => fmt::Display::fmt(&idx, f),
+        }
    }
 }
@@ -26,29 +29,38 @@ impl Name {
    /// Note: this is private to make creating name from random string hard.
    /// Hopefully, this should allow us to integrate hygiene cleaner in the
    /// future, and to switch to interned representation of names.
-    const fn new(text: SmolStr) -> Name {
+    const fn new_text(text: SmolStr) -> Name {
-        Name { text }
+        Name(Repr::Text(text))
    }
-    pub(crate) fn missing() -> Name {
+    pub(crate) fn new_tuple_field(idx: usize) -> Name {
-        Name::new("[missing name]".into())
+        Name(Repr::TupleField(idx))
+    }
+    /// Shortcut to create inline plain text name
+    const fn new_inline_ascii(len: usize, text: &[u8]) -> Name {
+        Name::new_text(SmolStr::new_inline_from_ascii(len, text))
    }
-    pub(crate) fn tuple_field_name(idx: usize) -> Name {
+    /// Resolve a name from the text of token.
-        Name::new(idx.to_string().into())
+    fn resolve(raw_text: &SmolStr) -> Name {
+        let raw_start = "r#";
+        if raw_text.as_str().starts_with(raw_start) {
+            Name::new_text(SmolStr::new(&raw_text[raw_start.len()..]))
+        } else {
+            Name::new_text(raw_text.clone())
+        }
    }
-    // There's should be no way to extract a string out of `Name`: `Name` in the
+    pub(crate) fn missing() -> Name {
-    // future, `Name` will include hygiene information, and you can't encode
+        Name::new_text("[missing name]".into())
-    // hygiene into a String.
+    }
-    //
-    // If you need to compare something with `Name`, compare `Name`s directly.
+    pub(crate) fn as_tuple_index(&self) -> Option<usize> {
-    //
+        match self.0 {
-    // If you need to render `Name` for the user, use the `Display` impl, but be
+            Repr::TupleField(idx) => Some(idx),
-    // aware that it strips hygiene info.
+            _ => None,
-    #[deprecated(note = "use to_string instead")]
+        }
-    pub fn as_smolstr(&self) -> &SmolStr {
-        &self.text
    }
 }
@@ -58,15 +70,16 @@ pub(crate) trait AsName {
 impl AsName for ast::NameRef {
    fn as_name(&self) -> Name {
-        let name = resolve_name(self.text());
+        match self.as_tuple_field() {
-        Name::new(name)
+            Some(idx) => Name::new_tuple_field(idx),
+            None => Name::resolve(self.text()),
+        }
    }
 }
 impl AsName for ast::Name {
    fn as_name(&self) -> Name {
-        let name = resolve_name(self.text());
+        Name::resolve(self.text())
-        Name::new(name)
    }
 }
@@ -74,66 +87,56 @@ impl AsName for ast::FieldKind {
    fn as_name(&self) -> Name {
        match self {
            ast::FieldKind::Name(nr) => nr.as_name(),
-            ast::FieldKind::Index(idx) => Name::new(idx.text().clone()),
+            ast::FieldKind::Index(idx) => Name::new_tuple_field(idx.text().parse().unwrap()),
        }
    }
 }
 impl AsName for ra_db::Dependency {
    fn as_name(&self) -> Name {
-        Name::new(self.name.clone())
+        Name::new_text(self.name.clone())
    }
 }
 // Primitives
-pub(crate) const ISIZE: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"isize"));
+pub(crate) const ISIZE: Name = Name::new_inline_ascii(5, b"isize");
-pub(crate) const I8: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"i8"));
+pub(crate) const I8: Name = Name::new_inline_ascii(2, b"i8");
-pub(crate) const I16: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i16"));
+pub(crate) const I16: Name = Name::new_inline_ascii(3, b"i16");
-pub(crate) const I32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i32"));
+pub(crate) const I32: Name = Name::new_inline_ascii(3, b"i32");
-pub(crate) const I64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"i64"));
+pub(crate) const I64: Name = Name::new_inline_ascii(3, b"i64");
-pub(crate) const I128: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"i128"));
+pub(crate) const I128: Name = Name::new_inline_ascii(4, b"i128");
-pub(crate) const USIZE: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"usize"));
+pub(crate) const USIZE: Name = Name::new_inline_ascii(5, b"usize");
-pub(crate) const U8: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"u8"));
+pub(crate) const U8: Name = Name::new_inline_ascii(2, b"u8");
-pub(crate) const U16: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u16"));
+pub(crate) const U16: Name = Name::new_inline_ascii(3, b"u16");
-pub(crate) const U32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u32"));
+pub(crate) const U32: Name = Name::new_inline_ascii(3, b"u32");
-pub(crate) const U64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"u64"));
+pub(crate) const U64: Name = Name::new_inline_ascii(3, b"u64");
-pub(crate) const U128: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"u128"));
+pub(crate) const U128: Name = Name::new_inline_ascii(4, b"u128");
-pub(crate) const F32: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"f32"));
+pub(crate) const F32: Name = Name::new_inline_ascii(3, b"f32");
-pub(crate) const F64: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"f64"));
+pub(crate) const F64: Name = Name::new_inline_ascii(3, b"f64");
-pub(crate) const BOOL: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"bool"));
+pub(crate) const BOOL: Name = Name::new_inline_ascii(4, b"bool");
-pub(crate) const CHAR: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"char"));
+pub(crate) const CHAR: Name = Name::new_inline_ascii(4, b"char");
-pub(crate) const STR: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"str"));
+pub(crate) const STR: Name = Name::new_inline_ascii(3, b"str");
 // Special names
-pub(crate) const SELF_PARAM: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"self"));
+pub(crate) const SELF_PARAM: Name = Name::new_inline_ascii(4, b"self");
-pub(crate) const SELF_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"Self"));
+pub(crate) const SELF_TYPE: Name = Name::new_inline_ascii(4, b"Self");
-pub(crate) const MACRO_RULES: Name = Name::new(SmolStr::new_inline_from_ascii(11, b"macro_rules"));
+pub(crate) const MACRO_RULES: Name = Name::new_inline_ascii(11, b"macro_rules");
 // Components of known path (value or mod name)
-pub(crate) const STD: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"std"));
+pub(crate) const STD: Name = Name::new_inline_ascii(3, b"std");
-pub(crate) const ITER: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"iter"));
+pub(crate) const ITER: Name = Name::new_inline_ascii(4, b"iter");
-pub(crate) const OPS: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"ops"));
+pub(crate) const OPS: Name = Name::new_inline_ascii(3, b"ops");
-pub(crate) const FUTURE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"future"));
+pub(crate) const FUTURE: Name = Name::new_inline_ascii(6, b"future");
-pub(crate) const RESULT: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"result"));
+pub(crate) const RESULT: Name = Name::new_inline_ascii(6, b"result");
-pub(crate) const BOXED: Name = Name::new(SmolStr::new_inline_from_ascii(5, b"boxed"));
+pub(crate) const BOXED: Name = Name::new_inline_ascii(5, b"boxed");
 // Components of known path (type name)
-pub(crate) const INTO_ITERATOR_TYPE: Name =
+pub(crate) const INTO_ITERATOR_TYPE: Name = Name::new_inline_ascii(12, b"IntoIterator");
-    Name::new(SmolStr::new_inline_from_ascii(12, b"IntoIterator"));
+pub(crate) const ITEM_TYPE: Name = Name::new_inline_ascii(4, b"Item");
-pub(crate) const ITEM_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(4, b"Item"));
+pub(crate) const TRY_TYPE: Name = Name::new_inline_ascii(3, b"Try");
-pub(crate) const TRY_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"Try"));
+pub(crate) const OK_TYPE: Name = Name::new_inline_ascii(2, b"Ok");
-pub(crate) const OK_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(2, b"Ok"));
+pub(crate) const FUTURE_TYPE: Name = Name::new_inline_ascii(6, b"Future");
-pub(crate) const FUTURE_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Future"));
+pub(crate) const RESULT_TYPE: Name = Name::new_inline_ascii(6, b"Result");
-pub(crate) const RESULT_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Result"));
+pub(crate) const OUTPUT_TYPE: Name = Name::new_inline_ascii(6, b"Output");
-pub(crate) const OUTPUT_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Output"));
+pub(crate) const TARGET_TYPE: Name = Name::new_inline_ascii(6, b"Target");
-pub(crate) const TARGET_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(6, b"Target"));
+pub(crate) const BOX_TYPE: Name = Name::new_inline_ascii(3, b"Box");
-pub(crate) const BOX_TYPE: Name = Name::new(SmolStr::new_inline_from_ascii(3, b"Box"));
-fn resolve_name(text: &SmolStr) -> SmolStr {
-    let raw_start = "r#";
-    if text.as_str().starts_with(raw_start) {
-        SmolStr::new(&text[raw_start.len()..])
-    } else {
-        text.clone()
-    }
-}
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index b808a0c36..67adcfa28 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -332,6 +332,20 @@ impl CrateDefMap {
    ) -> ResolvePathResult {
        let mut segments = path.segments.iter().enumerate();
        let mut curr_per_ns: PerNs = match path.kind {
+            PathKind::DollarCrate(krate) => {
+                if krate == self.krate {
+                    tested_by!(macro_dollar_crate_self);
+                    PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
+                } else {
+                    match krate.root_module(db) {
+                        Some(module) => {
+                            tested_by!(macro_dollar_crate_other);
+                            PerNs::types(module.into())
+                        }
+                        None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
+                    }
+                }
+            }
            PathKind::Crate => {
                PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
            }
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index ef7dc6ebe..cef2dc9d2 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -1,3 +1,6 @@
+//! FIXME: write short doc here
+use ra_cfg::CfgOptions;
 use ra_db::FileId;
 use ra_syntax::{ast, SmolStr};
 use rustc_hash::FxHashMap;
@@ -33,6 +36,9 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
        }
    }
+    let crate_graph = db.crate_graph();
+    let cfg_options = crate_graph.cfg_options(def_map.krate().crate_id());
    let mut collector = DefCollector {
        db,
        def_map,
@@ -40,6 +46,7 @@ pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> C
        unresolved_imports: Vec::new(),
        unexpanded_macros: Vec::new(),
        macro_stack_monitor: MacroStackMonitor::default(),
+        cfg_options,
    };
    collector.collect();
    collector.finish()
@@ -74,8 +81,8 @@ impl MacroStackMonitor {
 }
 /// Walks the tree of module recursively
-struct DefCollector<DB> {
+struct DefCollector<'a, DB> {
-    db: DB,
+    db: &'a DB,
    def_map: CrateDefMap,
    glob_imports: FxHashMap<CrateModuleId, Vec<(CrateModuleId, raw::ImportId)>>,
    unresolved_imports: Vec<(CrateModuleId, raw::ImportId, raw::ImportData)>,
@@ -84,9 +91,11 @@ struct DefCollector<DB> {
    /// Some macro use `$tt:tt which mean we have to handle the macro perfectly
    /// To prevent stack overflow, we add a deep counter here for prevent that.
    macro_stack_monitor: MacroStackMonitor,
+    cfg_options: &'a CfgOptions,
 }
-impl<'a, DB> DefCollector<&'a DB>
+impl<DB> DefCollector<'_, DB>
 where
    DB: DefDatabase,
 {
@@ -504,7 +513,7 @@ struct ModCollector<'a, D> {
    parent_module: Option<ParentModule<'a>>,
 }
-impl<DB> ModCollector<'_, &'_ mut DefCollector<&'_ DB>>
+impl<DB> ModCollector<'_, &'_ mut DefCollector<'_, DB>>
 where
    DB: DefDatabase,
 {
@@ -521,24 +530,27 @@ where
        // `#[macro_use] extern crate` is hoisted to imports macros before collecting
        // any other items.
        for item in items {
-            if let raw::RawItem::Import(import_id) = *item {
+            if self.is_cfg_enabled(&item.attrs) {
-                let import = self.raw_items[import_id].clone();
+                if let raw::RawItemKind::Import(import_id) = item.kind {
-                if import.is_extern_crate && import.is_macro_use {
+                    let import = self.raw_items[import_id].clone();
-                    self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
+                    if import.is_extern_crate && import.is_macro_use {
+                        self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
+                    }
                }
            }
        }
        for item in items {
-            match *item {
+            if self.is_cfg_enabled(&item.attrs) {
-                raw::RawItem::Module(m) => self.collect_module(&self.raw_items[m]),
+                match item.kind {
-                raw::RawItem::Import(import_id) => self.def_collector.unresolved_imports.push((
+                    raw::RawItemKind::Module(m) => self.collect_module(&self.raw_items[m]),
-                    self.module_id,
+                    raw::RawItemKind::Import(import_id) => self
-                    import_id,
+                        .def_collector
-                    self.raw_items[import_id].clone(),
+                        .unresolved_imports
-                )),
+                        .push((self.module_id, import_id, self.raw_items[import_id].clone())),
-                raw::RawItem::Def(def) => self.define_def(&self.raw_items[def]),
+                    raw::RawItemKind::Def(def) => self.define_def(&self.raw_items[def]),
-                raw::RawItem::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
+                    raw::RawItemKind::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
+                }
            }
        }
    }
@@ -662,7 +674,10 @@ where
        // Case 1: macro rules, define a macro in crate-global mutable scope
        if is_macro_rules(&mac.path) {
            if let Some(name) = &mac.name {
-                let macro_id = MacroDefId(mac.ast_id.with_file_id(self.file_id));
+                let macro_id = MacroDefId {
+                    ast_id: mac.ast_id.with_file_id(self.file_id),
+                    krate: self.def_collector.def_map.krate,
+                };
                let macro_ = MacroDef { id: macro_id };
                self.def_collector.define_macro(self.module_id, name.clone(), macro_, mac.export);
            }
@@ -698,6 +713,14 @@ where
            self.def_collector.define_legacy_macro(self.module_id, name.clone(), macro_);
        }
    }
+    fn is_cfg_enabled(&self, attrs: &raw::Attrs) -> bool {
+        attrs.as_ref().map_or(true, |attrs| {
+            attrs
+                .iter()
+                .all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
+        })
+    }
 }
 fn is_macro_rules(path: &Path) -> bool {
@@ -725,6 +748,7 @@ mod tests {
            unresolved_imports: Vec::new(),
            unexpanded_macros: Vec::new(),
            macro_stack_monitor: monitor,
+            cfg_options: &CfgOptions::default(),
        };
        collector.collect();
        collector.finish()
diff --git a/crates/ra_hir/src/nameres/per_ns.rs b/crates/ra_hir/src/nameres/per_ns.rs
index 964da2794..0da6789de 100644
--- a/crates/ra_hir/src/nameres/per_ns.rs
+++ b/crates/ra_hir/src/nameres/per_ns.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{MacroDef, ModuleDef};
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 29aaddbf1..623b343c4 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{ops::Index, sync::Arc};
 use ra_arena::{impl_arena_id, map::ArenaMap, Arena, RawId};
@@ -8,8 +10,9 @@ use ra_syntax::{
 use test_utils::tested_by;
 use crate::{
+    attr::Attr,
    db::{AstDatabase, DefDatabase},
-    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path,
+    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path, Source,
 };
 /// `RawItems` is a set of top-level items in a file (except for impls).
@@ -71,6 +74,8 @@ impl RawItems {
            raw_items: RawItems::default(),
            source_ast_id_map: db.ast_id_map(file_id),
            source_map: ImportSourceMap::default(),
+            file_id,
+            db,
        };
        if let Some(node) = db.parse_or_expand(file_id) {
            if let Some(source_file) = ast::SourceFile::cast(node.clone()) {
@@ -115,8 +120,17 @@ impl Index<Macro> for RawItems {
    }
 }
+// Avoid heap allocation on items without attributes.
+pub(super) type Attrs = Option<Arc<[Attr]>>;
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub(super) struct RawItem {
+    pub(super) attrs: Attrs,
+    pub(super) kind: RawItemKind,
+}
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub(super) enum RawItem {
+pub(super) enum RawItemKind {
    Module(Module),
    Import(ImportId),
    Def(Def),
@@ -192,13 +206,15 @@ pub(super) struct MacroData {
    pub(super) export: bool,
 }
-struct RawItemsCollector {
+struct RawItemsCollector<DB> {
    raw_items: RawItems,
    source_ast_id_map: Arc<AstIdMap>,
    source_map: ImportSourceMap,
+    file_id: HirFileId,
+    db: DB,
 }
-impl RawItemsCollector {
+impl<DB: AstDatabase> RawItemsCollector<&DB> {
    fn process_module(&mut self, current_module: Option<Module>, body: impl ast::ModuleItemOwner) {
        for item_or_macro in body.items_with_macros() {
            match item_or_macro {
@@ -209,6 +225,7 @@ impl RawItemsCollector {
    }
    fn add_item(&mut self, current_module: Option<Module>, item: ast::ModuleItem) {
+        let attrs = self.parse_attrs(&item);
        let (kind, name) = match item {
            ast::ModuleItem::Module(module) => {
                self.add_module(current_module, module);
@@ -257,7 +274,7 @@ impl RawItemsCollector {
        if let Some(name) = name {
            let name = name.as_name();
            let def = self.raw_items.defs.alloc(DefData { name, kind });
-            self.push_item(current_module, RawItem::Def(def))
+            self.push_item(current_module, attrs, RawItemKind::Def(def));
        }
    }
@@ -266,8 +283,10 @@ impl RawItemsCollector {
            Some(it) => it.as_name(),
            None => return,
        };
+        let attrs = self.parse_attrs(&module);
        let ast_id = self.source_ast_id_map.ast_id(&module);
+        // FIXME: cfg_attr
        let is_macro_use = module.has_atom_attr("macro_use");
        if module.has_semi() {
            let attr_path = extract_mod_path_attribute(&module);
@@ -277,7 +296,7 @@ impl RawItemsCollector {
                attr_path,
                is_macro_use,
            });
-            self.push_item(current_module, RawItem::Module(item));
+            self.push_item(current_module, attrs, RawItemKind::Module(item));
            return;
        }
@@ -291,26 +310,37 @@ impl RawItemsCollector {
                is_macro_use,
            });
            self.process_module(Some(item), item_list);
-            self.push_item(current_module, RawItem::Module(item));
+            self.push_item(current_module, attrs, RawItemKind::Module(item));
            return;
        }
        tested_by!(name_res_works_for_broken_modules);
    }
    fn add_use_item(&mut self, current_module: Option<Module>, use_item: ast::UseItem) {
+        // FIXME: cfg_attr
        let is_prelude = use_item.has_atom_attr("prelude_import");
+        let attrs = self.parse_attrs(&use_item);
-        Path::expand_use_item(&use_item, |path, use_tree, is_glob, alias| {
-            let import_data = ImportData {
+        Path::expand_use_item(
-                path,
+            Source { ast: use_item, file_id: self.file_id },
-                alias,
+            self.db,
-                is_glob,
+            |path, use_tree, is_glob, alias| {
-                is_prelude,
+                let import_data = ImportData {
-                is_extern_crate: false,
+                    path,
-                is_macro_use: false,
+                    alias,
-            };
+                    is_glob,
-            self.push_import(current_module, import_data, Either::A(AstPtr::new(use_tree)));
+                    is_prelude,
-        })
+                    is_extern_crate: false,
+                    is_macro_use: false,
+                };
+                self.push_import(
+                    current_module,
+                    attrs.clone(),
+                    import_data,
+                    Either::A(AstPtr::new(use_tree)),
+                );
+            },
+        )
    }
    fn add_extern_crate_item(
@@ -321,6 +351,8 @@ impl RawItemsCollector {
        if let Some(name_ref) = extern_crate.name_ref() {
            let path = Path::from_name_ref(&name_ref);
            let alias = extern_crate.alias().and_then(|a| a.name()).map(|it| it.as_name());
+            let attrs = self.parse_attrs(&extern_crate);
+            // FIXME: cfg_attr
            let is_macro_use = extern_crate.has_atom_attr("macro_use");
            let import_data = ImportData {
                path,
@@ -330,37 +362,47 @@ impl RawItemsCollector {
                is_extern_crate: true,
                is_macro_use,
            };
-            self.push_import(current_module, import_data, Either::B(AstPtr::new(&extern_crate)));
+            self.push_import(
+                current_module,
+                attrs,
+                import_data,
+                Either::B(AstPtr::new(&extern_crate)),
+            );
        }
    }
    fn add_macro(&mut self, current_module: Option<Module>, m: ast::MacroCall) {
-        let path = match m.path().and_then(Path::from_ast) {
+        let attrs = self.parse_attrs(&m);
+        let path = match m
+            .path()
+            .and_then(|path| Path::from_src(Source { ast: path, file_id: self.file_id }, self.db))
+        {
            Some(it) => it,
            _ => return,
        };
        let name = m.name().map(|it| it.as_name());
        let ast_id = self.source_ast_id_map.ast_id(&m);
-        let export = m.has_atom_attr("macro_export")
+        // FIXME: cfg_attr
-            || m.attrs().filter_map(|x| x.as_call()).any(|(name, _)| name == "macro_export");
+        let export = m.attrs().filter_map(|x| x.simple_name()).any(|name| name == "macro_export");
        let m = self.raw_items.macros.alloc(MacroData { ast_id, path, name, export });
-        self.push_item(current_module, RawItem::Macro(m));
+        self.push_item(current_module, attrs, RawItemKind::Macro(m));
    }
    fn push_import(
        &mut self,
        current_module: Option<Module>,
+        attrs: Attrs,
        data: ImportData,
        source: ImportSourcePtr,
    ) {
        let import = self.raw_items.imports.alloc(data);
        self.source_map.insert(import, source);
-        self.push_item(current_module, RawItem::Import(import))
+        self.push_item(current_module, attrs, RawItemKind::Import(import))
    }
-    fn push_item(&mut self, current_module: Option<Module>, item: RawItem) {
+    fn push_item(&mut self, current_module: Option<Module>, attrs: Attrs, kind: RawItemKind) {
        match current_module {
            Some(module) => match &mut self.raw_items.modules[module] {
                ModuleData::Definition { items, .. } => items,
@@ -368,13 +410,17 @@ impl RawItemsCollector {
            },
            None => &mut self.raw_items.items,
        }
-        .push(item)
+        .push(RawItem { attrs, kind })
+    }
+    fn parse_attrs(&self, item: &impl ast::AttrsOwner) -> Attrs {
+        Attr::from_attrs_owner(self.file_id, item, self.db)
    }
 }
 fn extract_mod_path_attribute(module: &ast::Module) -> Option<SmolStr> {
    module.attrs().into_iter().find_map(|attr| {
-        attr.as_key_value().and_then(|(name, value)| {
+        attr.as_simple_key_value().and_then(|(name, value)| {
            let is_path = name == "path";
            if is_path {
                Some(value)
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index bc4b47b70..34dd79574 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -7,6 +7,7 @@ mod mod_resolution;
 use std::sync::Arc;
 use insta::assert_snapshot;
+use ra_cfg::CfgOptions;
 use ra_db::SourceDatabase;
 use test_utils::covers;
@@ -507,3 +508,72 @@ fn values_dont_shadow_extern_crates() {
        ⋮foo: v
    "###);
 }
+#[test]
+fn cfg_not_test() {
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        use {Foo, Bar, Baz};
+        //- /lib.rs
+        #[prelude_import]
+        pub use self::prelude::*;
+        mod prelude {
+            #[cfg(test)]
+            pub struct Foo;
+            #[cfg(not(test))]
+            pub struct Bar;
+            #[cfg(all(not(any()), feature = "foo", feature = "bar", opt = "42"))]
+            pub struct Baz;
+        }
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/lib.rs", []),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮Baz: _
+        ⋮Foo: _
+    "###);
+}
+#[test]
+fn cfg_test() {
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        use {Foo, Bar, Baz};
+        //- /lib.rs
+        #[prelude_import]
+        pub use self::prelude::*;
+        mod prelude {
+            #[cfg(test)]
+            pub struct Foo;
+            #[cfg(not(test))]
+            pub struct Bar;
+            #[cfg(all(not(any()), feature = "foo", feature = "bar", opt = "42"))]
+            pub struct Baz;
+        }
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/lib.rs", [], CfgOptions::default()
+                .atom("test".into())
+                .key_value("feature".into(), "foo".into())
+                .key_value("feature".into(), "bar".into())
+                .key_value("opt".into(), "42".into())
+            ),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: _
+        ⋮Baz: t v
+        ⋮Foo: t v
+    "###);
+}
diff --git a/crates/ra_hir/src/nameres/tests/macros.rs b/crates/ra_hir/src/nameres/tests/macros.rs
index bd60f4258..e4b408394 100644
--- a/crates/ra_hir/src/nameres/tests/macros.rs
+++ b/crates/ra_hir/src/nameres/tests/macros.rs
@@ -515,3 +515,108 @@ fn path_qualified_macros() {
        ⋮not_found: _
    "###);
 }
+#[test]
+fn macro_dollar_crate_is_correct_in_item() {
+    covers!(macro_dollar_crate_self);
+    covers!(macro_dollar_crate_other);
+    let map = def_map_with_crate_graph(
+        "
+        //- /main.rs
+        #[macro_use]
+        extern crate foo;
+        #[macro_use]
+        mod m {
+            macro_rules! current {
+                () => {
+                    use $crate::Foo as FooSelf;
+                }
+            }
+        }
+        struct Foo;
+        current!();
+        not_current1!();
+        foo::not_current2!();
+        //- /lib.rs
+        mod m {
+            #[macro_export]
+            macro_rules! not_current1 {
+                () => {
+                    use $crate::Bar;
+                }
+            }
+        }
+        #[macro_export]
+        macro_rules! not_current2 {
+            () => {
+                use $crate::Baz;
+            }
+        }
+        struct Bar;
+        struct Baz;
+        ",
+        crate_graph! {
+            "main": ("/main.rs", ["foo"]),
+            "foo": ("/lib.rs", []),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮Bar: t v
+        ⋮Baz: t v
+        ⋮Foo: t v
+        ⋮FooSelf: t v
+        ⋮foo: t
+        ⋮m: t
+        ⋮
+        ⋮crate::m
+    "###);
+}
+#[test]
+fn macro_dollar_crate_is_correct_in_indirect_deps() {
+    covers!(macro_dollar_crate_other);
+    // From std
+    let map = def_map_with_crate_graph(
+        r#"
+        //- /main.rs
+        foo!();
+        //- /std.rs
+        #[prelude_import]
+        use self::prelude::*;
+        pub use core::foo;
+        mod prelude {}
+        #[macro_use]
+        mod std_macros;
+        //- /core.rs
+        #[macro_export]
+        macro_rules! foo {
+            () => {
+                use $crate::bar;
+            }
+        }
+        pub struct bar;
+        "#,
+        crate_graph! {
+            "main": ("/main.rs", ["std"]),
+            "std": ("/std.rs", ["core"]),
+            "core": ("/core.rs", []),
+        },
+    );
+    assert_snapshot!(map, @r###"
+        ⋮crate
+        ⋮bar: t v
+    "###);
+}
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index 39d1b7e46..394617e1a 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{iter, sync::Arc};
 use ra_syntax::{
@@ -5,7 +7,7 @@ use ra_syntax::{
    AstNode,
 };
-use crate::{name, type_ref::TypeRef, AsName, Name};
+use crate::{db::AstDatabase, name, type_ref::TypeRef, AsName, Crate, Name, Source};
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Path {
@@ -52,16 +54,19 @@ pub enum PathKind {
    Abs,
    // Type based path like `<T>::foo`
    Type(Box<TypeRef>),
+    // `$crate` from macro expansion
+    DollarCrate(Crate),
 }
 impl Path {
    /// Calls `cb` with all paths, represented by this use item.
    pub fn expand_use_item(
-        item: &ast::UseItem,
+        item_src: Source<ast::UseItem>,
+        db: &impl AstDatabase,
        mut cb: impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
    ) {
-        if let Some(tree) = item.use_tree() {
+        if let Some(tree) = item_src.ast.use_tree() {
-            expand_use_tree(None, tree, &mut cb);
+            expand_use_tree(None, tree, &|| item_src.file_id.macro_crate(db), &mut cb);
        }
    }
@@ -76,7 +81,19 @@ impl Path {
    }
    /// Converts an `ast::Path` to `Path`. Works with use trees.
-    pub fn from_ast(mut path: ast::Path) -> Option<Path> {
+    /// DEPRECATED: It does not handle `$crate` from macro call.
+    pub fn from_ast(path: ast::Path) -> Option<Path> {
+        Path::parse(path, &|| None)
+    }
+    /// Converts an `ast::Path` to `Path`. Works with use trees.
+    /// It correctly handles `$crate` based path from macro call.
+    pub fn from_src(source: Source<ast::Path>, db: &impl AstDatabase) -> Option<Path> {
+        let file_id = source.file_id;
+        Path::parse(source.ast, &|| file_id.macro_crate(db))
+    }
+    fn parse(mut path: ast::Path, macro_crate: &impl Fn() -> Option<Crate>) -> Option<Path> {
        let mut kind = PathKind::Plain;
        let mut segments = Vec::new();
        loop {
@@ -88,6 +105,13 @@ impl Path {
            match segment.kind()? {
                ast::PathSegmentKind::Name(name) => {
+                    if name.text() == "$crate" {
+                        if let Some(macro_crate) = macro_crate() {
+                            kind = PathKind::DollarCrate(macro_crate);
+                            break;
+                        }
+                    }
                    let args = segment
                        .type_arg_list()
                        .and_then(GenericArgs::from_ast)
@@ -113,7 +137,7 @@ impl Path {
                        }
                        // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
                        Some(trait_ref) => {
-                            let path = Path::from_ast(trait_ref.path()?)?;
+                            let path = Path::parse(trait_ref.path()?, macro_crate)?;
                            kind = path.kind;
                            let mut prefix_segments = path.segments;
                            prefix_segments.reverse();
@@ -264,6 +288,7 @@ impl From<Name> for Path {
 fn expand_use_tree(
    prefix: Option<Path>,
    tree: ast::UseTree,
+    macro_crate: &impl Fn() -> Option<Crate>,
    cb: &mut impl FnMut(Path, &ast::UseTree, bool, Option<Name>),
 ) {
    if let Some(use_tree_list) = tree.use_tree_list() {
@@ -272,13 +297,13 @@ fn expand_use_tree(
            None => prefix,
            // E.g. `use something::{inner}` (prefix is `None`, path is `something`)
            // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`)
-            Some(path) => match convert_path(prefix, path) {
+            Some(path) => match convert_path(prefix, path, macro_crate) {
                Some(it) => Some(it),
                None => return, // FIXME: report errors somewhere
            },
        };
        for child_tree in use_tree_list.use_trees() {
-            expand_use_tree(prefix.clone(), child_tree, cb);
+            expand_use_tree(prefix.clone(), child_tree, macro_crate, cb);
        }
    } else {
        let alias = tree.alias().and_then(|a| a.name()).map(|a| a.as_name());
@@ -295,7 +320,7 @@ fn expand_use_tree(
                    }
                }
            }
-            if let Some(path) = convert_path(prefix, ast_path) {
+            if let Some(path) = convert_path(prefix, ast_path, macro_crate) {
                let is_glob = tree.has_star();
                cb(path, &tree, is_glob, alias)
            }
@@ -305,12 +330,29 @@ fn expand_use_tree(
    }
 }
-fn convert_path(prefix: Option<Path>, path: ast::Path) -> Option<Path> {
+fn convert_path(
-    let prefix =
+    prefix: Option<Path>,
-        if let Some(qual) = path.qualifier() { Some(convert_path(prefix, qual)?) } else { prefix };
+    path: ast::Path,
+    macro_crate: &impl Fn() -> Option<Crate>,
+) -> Option<Path> {
+    let prefix = if let Some(qual) = path.qualifier() {
+        Some(convert_path(prefix, qual, macro_crate)?)
+    } else {
+        prefix
+    };
    let segment = path.segment()?;
    let res = match segment.kind()? {
        ast::PathSegmentKind::Name(name) => {
+            if name.text() == "$crate" {
+                if let Some(krate) = macro_crate() {
+                    return Some(Path::from_simple_segments(
+                        PathKind::DollarCrate(krate),
+                        iter::empty(),
+                    ));
+                }
+            }
            // no type args in use
            let mut res = prefix
                .unwrap_or_else(|| Path { kind: PathKind::Plain, segments: Vec::with_capacity(1) });
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index bd4be8430..088335e66 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -1,10 +1,10 @@
-/// Lookup hir elements using positions in the source code. This is a lossy
+//! Lookup hir elements using positions in the source code. This is a lossy
-/// transformation: in general, a single source might correspond to several
+//! transformation: in general, a single source might correspond to several
-/// modules, functions, etc, due to macros, cfgs and `#[path=]` attributes on
+//! modules, functions, etc, due to macros, cfgs and `#[path=]` attributes on
-/// modules.
+//! modules.
-///
+//!
-/// So, this modules should not be used during hir construction, it exists
+//! So, this modules should not be used during hir construction, it exists
-/// purely for "IDE needs".
+//! purely for "IDE needs".
 use std::sync::Arc;
 use ra_db::FileId;
@@ -203,6 +203,7 @@ impl SourceAnalyzer {
        db: &impl HirDatabase,
        macro_call: &ast::MacroCall,
    ) -> Option<MacroDef> {
+        // This must be a normal source file rather than macro file.
        let path = macro_call.path().and_then(Path::from_ast)?;
        self.resolver.resolve_path_as_macro(db, &path)
    }
@@ -261,6 +262,7 @@ impl SourceAnalyzer {
                return Some(PathResolution::AssocItem(assoc));
            }
        }
+        // This must be a normal source file rather than macro file.
        let hir_path = crate::Path::from_ast(path.clone())?;
        self.resolve_hir_path(db, &hir_path)
    }
diff --git a/crates/ra_hir/src/source_id.rs b/crates/ra_hir/src/source_id.rs
index 04574876d..a4dd99598 100644
--- a/crates/ra_hir/src/source_id.rs
+++ b/crates/ra_hir/src/source_id.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    hash::{Hash, Hasher},
    marker::PhantomData,
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index fae9c1e22..d161735e8 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -14,11 +14,11 @@ pub(crate) mod display;
 use std::ops::Deref;
 use std::sync::Arc;
-use std::{fmt, mem};
+use std::{fmt, iter, mem};
 use crate::{
-    db::HirDatabase, expr::ExprId, type_ref::Mutability, Adt, DefWithBody, GenericParams, Name,
+    db::HirDatabase, expr::ExprId, type_ref::Mutability, Adt, Crate, DefWithBody, GenericParams,
-    Trait, TypeAlias,
+    HasGenericParams, Name, Trait, TypeAlias,
 };
 use display::{HirDisplay, HirFormatter};
@@ -111,6 +111,81 @@ pub enum TypeCtor {
    Closure { def: DefWithBody, expr: ExprId },
 }
+impl TypeCtor {
+    pub fn num_ty_params(self, db: &impl HirDatabase) -> usize {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never => 0,
+            TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::Closure { .. } // 1 param representing the signature of the closure
+            => 1,
+            TypeCtor::Adt(adt) => {
+                let generic_params = adt.generic_params(db);
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::FnDef(callable) => {
+                let generic_params = callable.generic_params(db);
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::AssociatedType(type_alias) => {
+                let generic_params = type_alias.generic_params(db);
+                generic_params.count_params_including_parent()
+            }
+            TypeCtor::FnPtr { num_args } => num_args as usize + 1,
+            TypeCtor::Tuple { cardinality } => cardinality as usize,
+        }
+    }
+    pub fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never
+            | TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::FnPtr { .. }
+            | TypeCtor::Tuple { .. } => None,
+            TypeCtor::Closure { def, .. } => def.krate(db),
+            TypeCtor::Adt(adt) => adt.krate(db),
+            TypeCtor::FnDef(callable) => callable.krate(db),
+            TypeCtor::AssociatedType(type_alias) => type_alias.krate(db),
+        }
+    }
+    pub fn as_generic_def(self) -> Option<crate::generics::GenericDef> {
+        match self {
+            TypeCtor::Bool
+            | TypeCtor::Char
+            | TypeCtor::Int(_)
+            | TypeCtor::Float(_)
+            | TypeCtor::Str
+            | TypeCtor::Never
+            | TypeCtor::Slice
+            | TypeCtor::Array
+            | TypeCtor::RawPtr(_)
+            | TypeCtor::Ref(_)
+            | TypeCtor::FnPtr { .. }
+            | TypeCtor::Tuple { .. }
+            | TypeCtor::Closure { .. } => None,
+            TypeCtor::Adt(adt) => Some(adt.into()),
+            TypeCtor::FnDef(callable) => Some(callable.into()),
+            TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
+        }
+    }
+}
 /// A nominal type with (maybe 0) type parameters. This might be a primitive
 /// type like `bool`, a struct, tuple, function pointer, reference or
 /// several other things.
@@ -271,11 +346,65 @@ impl Substs {
                .into(),
        )
    }
+    pub fn build_for_def(
+        db: &impl HirDatabase,
+        def: impl crate::HasGenericParams,
+    ) -> SubstsBuilder {
+        let params = def.generic_params(db);
+        let param_count = params.count_params_including_parent();
+        Substs::builder(param_count)
+    }
+    pub fn build_for_generics(generic_params: &GenericParams) -> SubstsBuilder {
+        Substs::builder(generic_params.count_params_including_parent())
+    }
+    pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
+        Substs::builder(type_ctor.num_ty_params(db))
+    }
+    fn builder(param_count: usize) -> SubstsBuilder {
+        SubstsBuilder { vec: Vec::with_capacity(param_count), param_count }
+    }
+}
+#[derive(Debug, Clone)]
+pub struct SubstsBuilder {
+    vec: Vec<Ty>,
+    param_count: usize,
 }
-impl From<Vec<Ty>> for Substs {
+impl SubstsBuilder {
-    fn from(v: Vec<Ty>) -> Self {
+    pub fn build(self) -> Substs {
-        Substs(v.into())
+        assert_eq!(self.vec.len(), self.param_count);
+        Substs(self.vec.into())
+    }
+    pub fn push(mut self, ty: Ty) -> Self {
+        self.vec.push(ty);
+        self
+    }
+    fn remaining(&self) -> usize {
+        self.param_count - self.vec.len()
+    }
+    pub fn fill_with_bound_vars(mut self, starting_from: u32) -> Self {
+        self.vec.extend((starting_from..starting_from + self.remaining() as u32).map(Ty::Bound));
+        self
+    }
+    pub fn fill_with_unknown(mut self) -> Self {
+        self.vec.extend(iter::repeat(Ty::Unknown).take(self.remaining()));
+        self
+    }
+    pub fn use_parent_substs(mut self, parent_substs: &Substs) -> Self {
+        assert!(self.vec.is_empty());
+        assert!(parent_substs.len() <= self.param_count);
+        self.vec.extend(parent_substs.iter().cloned());
+        self
    }
 }
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 94f8ecdc9..02492ca14 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -7,7 +7,7 @@ use std::iter::successors;
 use log::{info, warn};
-use super::{traits::Solution, Canonical, Ty, TypeWalk};
+use super::{traits::Solution, Canonical, Substs, Ty, TypeWalk};
 use crate::{db::HirDatabase, name, HasGenericParams, Resolver};
 const AUTODEREF_RECURSION_LIMIT: usize = 10;
@@ -44,7 +44,8 @@ fn deref_by_trait(
    };
    let target = deref_trait.associated_type_by_name(db, &name::TARGET_TYPE)?;
-    if target.generic_params(db).count_params_including_parent() != 1 {
+    let generic_params = target.generic_params(db);
+    if generic_params.count_params_including_parent() != 1 {
        // the Target type + Deref trait should only have one generic parameter,
        // namely Deref's Self type
        return None;
@@ -54,12 +55,13 @@ fn deref_by_trait(
    let env = super::lower::trait_env(db, resolver);
+    let parameters = Substs::build_for_generics(&generic_params)
+        .push(ty.value.clone().shift_bound_vars(1))
+        .build();
    let projection = super::traits::ProjectionPredicate {
        ty: Ty::Bound(0),
-        projection_ty: super::ProjectionTy {
+        projection_ty: super::ProjectionTy { associated_ty: target, parameters },
-            associated_ty: target,
-            parameters: vec![ty.value.clone().shift_bound_vars(1)].into(),
-        },
    };
    let obligation = super::Obligation::Projection(projection);
diff --git a/crates/ra_hir/src/ty/display.rs b/crates/ra_hir/src/ty/display.rs
index 63ec9d7e1..7910429d7 100644
--- a/crates/ra_hir/src/ty/display.rs
+++ b/crates/ra_hir/src/ty/display.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 use crate::db::HirDatabase;
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index db3377357..ca9aefc42 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -609,7 +609,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
        for (i, &subpat) in subpats.iter().enumerate() {
            let expected_ty = def
-                .and_then(|d| d.field(self.db, &Name::tuple_field_name(i)))
+                .and_then(|d| d.field(self.db, &Name::new_tuple_field(i)))
                .map_or(Ty::Unknown, |field| field.ty(self.db))
                .subst(&substs);
            let expected_ty = self.normalize_associated_types_in(expected_ty);
@@ -688,14 +688,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                };
                let expectations_iter = expectations.iter().chain(repeat(&Ty::Unknown));
-                let inner_tys: Substs = args
+                let inner_tys = args
                    .iter()
                    .zip(expectations_iter)
                    .map(|(&pat, ty)| self.infer_pat(pat, ty, default_bm))
-                    .collect::<Vec<_>>()
+                    .collect();
-                    .into();
-                Ty::apply(TypeCtor::Tuple { cardinality: inner_tys.len() as u16 }, inner_tys)
+                Ty::apply(TypeCtor::Tuple { cardinality: args.len() as u16 }, Substs(inner_tys))
            }
            Pat::Ref { pat, mutability } => {
                let expectation = match expected.as_reference() {
@@ -1229,7 +1228,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                            ty: pat_ty.clone(),
                            projection_ty: ProjectionTy {
                                associated_ty: into_iter_item_alias,
-                                parameters: vec![iterable_ty].into(),
+                                parameters: Substs::single(iterable_ty),
                            },
                        };
                        self.obligations.push(Obligation::Projection(projection));
@@ -1262,7 +1261,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                sig_tys.push(ret_ty.clone());
                let sig_ty = Ty::apply(
                    TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
-                    sig_tys.into(),
+                    Substs(sig_tys.into()),
                );
                let closure_ty = Ty::apply_one(
                    TypeCtor::Closure { def: self.body.owner(), expr: tgt_expr },
@@ -1375,10 +1374,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                )
                .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) {
                    Ty::Apply(a_ty) => match a_ty.ctor {
-                        TypeCtor::Tuple { .. } => {
+                        TypeCtor::Tuple { .. } => name
-                            let i = name.to_string().parse::<usize>().ok();
+                            .as_tuple_index()
-                            i.and_then(|i| a_ty.parameters.0.get(i).cloned())
+                            .and_then(|idx| a_ty.parameters.0.get(idx).cloned()),
-                        }
                        TypeCtor::Adt(Adt::Struct(s)) => s.field(self.db, name).map(|field| {
                            self.write_field_resolution(tgt_expr, field);
                            field.ty(self.db).subst(&a_ty.parameters)
@@ -1400,7 +1398,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                            ty: ty.clone(),
                            projection_ty: ProjectionTy {
                                associated_ty: future_future_output_alias,
-                                parameters: vec![inner_ty].into(),
+                                parameters: Substs::single(inner_ty),
                            },
                        };
                        self.obligations.push(Obligation::Projection(projection));
@@ -1419,7 +1417,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                            ty: ty.clone(),
                            projection_ty: ProjectionTy {
                                associated_ty: ops_try_ok_alias,
-                                parameters: vec![inner_ty].into(),
+                                parameters: Substs::single(inner_ty),
                            },
                        };
                        self.obligations.push(Obligation::Projection(projection));
@@ -1604,6 +1602,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
        tail: Option<ExprId>,
        expected: &Expectation,
    ) -> Ty {
+        let mut diverges = false;
        for stmt in statements {
            match stmt {
                Statement::Let { pat, type_ref, initializer } => {
@@ -1625,16 +1624,23 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                    self.infer_pat(*pat, &ty, BindingMode::default());
                }
                Statement::Expr(expr) => {
-                    self.infer_expr(*expr, &Expectation::none());
+                    if let ty_app!(TypeCtor::Never) = self.infer_expr(*expr, &Expectation::none()) {
+                        diverges = true;
+                    }
                }
            }
        }
-        if let Some(expr) = tail {
+        let ty = if let Some(expr) = tail {
            self.infer_expr_coerce(expr, expected)
        } else {
            self.coerce(&Ty::unit(), &expected.ty);
            Ty::unit()
+        };
+        if diverges {
+            Ty::simple(TypeCtor::Never)
+        } else {
+            ty
        }
    }
diff --git a/crates/ra_hir/src/ty/infer/path.rs b/crates/ra_hir/src/ty/infer/path.rs
index feb7481b2..db979353a 100644
--- a/crates/ra_hir/src/ty/infer/path.rs
+++ b/crates/ra_hir/src/ty/infer/path.rs
@@ -158,13 +158,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
            AssocItem::Const(c) => ValueNs::Const(c),
            AssocItem::TypeAlias(_) => unreachable!(),
        };
-        let generics = item.generic_params(self.db);
+        let substs = Substs::build_for_def(self.db, item)
-        let mut substs = Vec::with_capacity(generics.count_params_including_parent());
+            .use_parent_substs(&trait_ref.substs)
-        substs.extend(trait_ref.substs.iter().cloned());
+            .fill_with_unknown()
-        substs.extend(std::iter::repeat(Ty::Unknown).take(generics.params.len()));
+            .build();
        self.write_assoc_resolution(id, item);
-        Some((def, Some(substs.into())))
+        Some((def, Some(substs)))
    }
    fn resolve_ty_assoc_item(
diff --git a/crates/ra_hir/src/ty/infer/unify.rs b/crates/ra_hir/src/ty/infer/unify.rs
index b6ebee3b1..d161aa6b3 100644
--- a/crates/ra_hir/src/ty/infer/unify.rs
+++ b/crates/ra_hir/src/ty/infer/unify.rs
@@ -3,7 +3,8 @@
 use super::{InferenceContext, Obligation};
 use crate::db::HirDatabase;
 use crate::ty::{
-    Canonical, InEnvironment, InferTy, ProjectionPredicate, ProjectionTy, TraitRef, Ty, TypeWalk,
+    Canonical, InEnvironment, InferTy, ProjectionPredicate, ProjectionTy, Substs, TraitRef, Ty,
+    TypeWalk,
 };
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
@@ -74,12 +75,9 @@ where
    }
    fn do_canonicalize_trait_ref(&mut self, trait_ref: TraitRef) -> TraitRef {
-        let substs = trait_ref
+        let substs =
-            .substs
+            trait_ref.substs.iter().map(|ty| self.do_canonicalize_ty(ty.clone())).collect();
-            .iter()
+        TraitRef { trait_: trait_ref.trait_, substs: Substs(substs) }
-            .map(|ty| self.do_canonicalize_ty(ty.clone()))
-            .collect::<Vec<_>>();
-        TraitRef { trait_: trait_ref.trait_, substs: substs.into() }
    }
    fn into_canonicalized<T>(self, result: T) -> Canonicalized<T> {
@@ -90,12 +88,9 @@ where
    }
    fn do_canonicalize_projection_ty(&mut self, projection_ty: ProjectionTy) -> ProjectionTy {
-        let params = projection_ty
+        let params =
-            .parameters
+            projection_ty.parameters.iter().map(|ty| self.do_canonicalize_ty(ty.clone())).collect();
-            .iter()
+        ProjectionTy { associated_ty: projection_ty.associated_ty, parameters: Substs(params) }
-            .map(|ty| self.do_canonicalize_ty(ty.clone()))
-            .collect::<Vec<_>>();
-        ProjectionTy { associated_ty: projection_ty.associated_ty, parameters: params.into() }
    }
    fn do_canonicalize_projection_predicate(
@@ -153,8 +148,7 @@ impl<T> Canonicalized<T> {
        solution: Canonical<Vec<Ty>>,
    ) {
        // the solution may contain new variables, which we need to convert to new inference vars
-        let new_vars =
+        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.new_type_var()).collect());
-            (0..solution.num_vars).map(|_| ctx.new_type_var()).collect::<Vec<_>>().into();
        for (i, ty) in solution.value.into_iter().enumerate() {
            let var = self.free_vars[i];
            ctx.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index dd503d771..4b67c82e7 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -239,14 +239,10 @@ impl Ty {
        let traits = traits_from_env.flat_map(|t| t.all_super_traits(db));
        for t in traits {
            if let Some(associated_ty) = t.associated_type_by_name(db, &segment.name) {
-                let generics = t.generic_params(db);
+                let substs =
-                let mut substs = Vec::new();
+                    Substs::build_for_def(db, t).push(self_ty.clone()).fill_with_unknown().build();
-                substs.push(self_ty.clone());
-                substs.extend(
-                    iter::repeat(Ty::Unknown).take(generics.count_params_including_parent() - 1),
-                );
                // FIXME handle type parameters on the segment
-                return Ty::Projection(ProjectionTy { associated_ty, parameters: substs.into() });
+                return Ty::Projection(ProjectionTy { associated_ty, parameters: substs });
            }
        }
        Ty::Unknown
@@ -766,6 +762,16 @@ pub enum CallableDef {
 }
 impl_froms!(CallableDef: Function, Struct, EnumVariant);
+impl CallableDef {
+    pub fn krate(self, db: &impl HirDatabase) -> Option<crate::Crate> {
+        match self {
+            CallableDef::Function(f) => f.krate(db),
+            CallableDef::Struct(s) => s.krate(db),
+            CallableDef::EnumVariant(e) => e.parent_enum(db).krate(db),
+        }
+    }
+}
 impl From<CallableDef> for GenericDef {
    fn from(def: CallableDef) -> GenericDef {
        match def {
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index 4b71b376f..ad2ab560d 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -10,7 +10,6 @@ use rustc_hash::FxHashMap;
 use super::{autoderef, lower, Canonical, InEnvironment, TraitEnvironment, TraitRef};
 use crate::{
    db::HirDatabase,
-    generics::HasGenericParams,
    impl_block::{ImplBlock, ImplId},
    nameres::CrateModuleId,
    resolve::Resolver,
@@ -331,20 +330,13 @@ fn generic_implements_goal(
    trait_: Trait,
    self_ty: Canonical<Ty>,
 ) -> Canonical<InEnvironment<super::Obligation>> {
-    let mut substs = Vec::new();
-    let generics = trait_.generic_params(db);
    let num_vars = self_ty.num_vars;
-    substs.push(self_ty.value);
+    let substs = super::Substs::build_for_def(db, trait_)
-    substs.extend(
+        .push(self_ty.value)
-        generics
+        .fill_with_bound_vars(num_vars as u32)
-            .params_including_parent()
+        .build();
-            .into_iter()
-            .skip(1)
-            .enumerate()
-            .map(|(i, _p)| Ty::Bound((i + num_vars) as u32)),
-    );
    let num_vars = substs.len() - 1 + self_ty.num_vars;
-    let trait_ref = TraitRef { trait_, substs: substs.into() };
+    let trait_ref = TraitRef { trait_, substs };
    let obligation = super::Obligation::Trait(trait_ref);
    Canonical { num_vars, value: InEnvironment::new(env, obligation) }
 }
diff --git a/crates/ra_hir/src/ty/op.rs b/crates/ra_hir/src/ty/op.rs
index 1b30a5b9b..bcfa3a6a2 100644
--- a/crates/ra_hir/src/ty/op.rs
+++ b/crates/ra_hir/src/ty/op.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::{InferTy, Ty, TypeCtor};
 use crate::{
    expr::{BinaryOp, CmpOp},
diff --git a/crates/ra_hir/src/ty/primitive.rs b/crates/ra_hir/src/ty/primitive.rs
index 2c60fefd6..8966f9d1d 100644
--- a/crates/ra_hir/src/ty/primitive.rs
+++ b/crates/ra_hir/src/ty/primitive.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 4362bb27a..25dad81eb 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -3,6 +3,7 @@ use std::sync::Arc;
 use insta::assert_snapshot;
+use ra_cfg::CfgOptions;
 use ra_db::{salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
    algo,
@@ -24,6 +25,50 @@ mod never_type;
 mod coercion;
 #[test]
+fn cfg_impl_block() {
+    let (mut db, pos) = MockDatabase::with_position(
+        r#"
+//- /main.rs
+use foo::S as T;
+struct S;
+#[cfg(test)]
+impl S {
+    fn foo1(&self) -> i32 { 0 }
+}
+#[cfg(not(test))]
+impl S {
+    fn foo2(&self) -> i32 { 0 }
+}
+fn test() {
+    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
+    t<|>;
+}
+//- /foo.rs
+struct S;
+#[cfg(not(test))]
+impl S {
+    fn foo3(&self) -> i32 { 0 }
+}
+#[cfg(test)]
+impl S {
+    fn foo4(&self) -> i32 { 0 }
+}
+"#,
+    );
+    db.set_crate_graph_from_fixture(crate_graph! {
+        "main": ("/main.rs", ["foo"], CfgOptions::default().atom("test".into())),
+        "foo": ("/foo.rs", []),
+    });
+    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
+}
+#[test]
 fn infer_await() {
    let (mut db, pos) = MockDatabase::with_position(
        r#"
@@ -218,7 +263,7 @@ fn test(a: u32, b: isize, c: !, d: &str) {
    [17; 18) 'b': isize
    [27; 28) 'c': !
    [33; 34) 'd': &str
-    [42; 121) '{     ...f32; }': ()
+    [42; 121) '{     ...f32; }': !
    [48; 49) 'a': u32
    [55; 56) 'b': isize
    [62; 63) 'c': !
@@ -981,6 +1026,67 @@ fn main(foo: Foo) {
 }
 #[test]
+fn infer_if_match_with_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() {
+    let _x1 = if true {
+        1
+    } else {
+        return;
+    };
+    let _x2 = if true {
+        2
+    } else {
+        return
+    };
+    let _x3 = match true {
+        true => 3,
+        _ => {
+            return;
+        }
+    };
+    let _x4 = match true {
+        true => 4,
+        _ => return
+    };
+}"#),
+        @r###"
+    [10; 323) '{     ...  }; }': ()
+    [20; 23) '_x1': i32
+    [26; 80) 'if tru...     }': i32
+    [29; 33) 'true': bool
+    [34; 51) '{     ...     }': i32
+    [44; 45) '1': i32
+    [57; 80) '{     ...     }': !
+    [67; 73) 'return': !
+    [90; 93) '_x2': i32
+    [96; 149) 'if tru...     }': i32
+    [99; 103) 'true': bool
+    [104; 121) '{     ...     }': i32
+    [114; 115) '2': i32
+    [127; 149) '{     ...     }': !
+    [137; 143) 'return': !
+    [159; 162) '_x3': i32
+    [165; 247) 'match ...     }': i32
+    [171; 175) 'true': bool
+    [186; 190) 'true': bool
+    [194; 195) '3': i32
+    [205; 206) '_': bool
+    [210; 241) '{     ...     }': !
+    [224; 230) 'return': !
+    [257; 260) '_x4': i32
+    [263; 320) 'match ...     }': i32
+    [269; 273) 'true': bool
+    [284; 288) 'true': bool
+    [292; 293) '4': i32
+    [303; 304) '_': bool
+    [308; 314) 'return': !
+    "###
+    )
+}
+#[test]
 fn infer_inherent_method() {
    assert_snapshot!(
        infer(r#"
@@ -3130,6 +3236,39 @@ fn test() { S.foo()<|>; }
    assert_eq!(t, "u128");
 }
+#[test]
+fn infer_macro_with_dollar_crate_is_correct_in_expr() {
+    covers!(macro_dollar_crate_other);
+    let (mut db, pos) = MockDatabase::with_position(
+        r#"
+//- /main.rs
+fn test() {
+    let x = (foo::foo!(1), foo::foo!(2));
+    x<|>;
+}
+//- /lib.rs
+#[macro_export]
+macro_rules! foo {
+    (1) => { $crate::bar!() };
+    (2) => { 1 + $crate::baz() };
+}
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+pub fn baz() -> usize { 31usize }
+"#,
+    );
+    db.set_crate_graph_from_fixture(crate_graph! {
+        "main": ("/main.rs", ["foo"]),
+        "foo": ("/lib.rs", []),
+    });
+    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
+}
 #[ignore]
 #[test]
 fn method_resolution_trait_before_autoref() {
@@ -3321,7 +3460,6 @@ fn test() { S2.into()<|>; }
 #[test]
 fn method_resolution_encountering_fn_type() {
-    covers!(trait_resolution_on_fn_type);
    type_at(
        r#"
 //- /main.rs
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index d11dab294..b0f67ae50 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -1,9 +1,8 @@
 //! Trait solving using Chalk.
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 use chalk_ir::cast::Cast;
 use log::debug;
-use parking_lot::Mutex;
 use ra_db::salsa;
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
@@ -38,7 +37,14 @@ impl TraitSolver {
    ) -> Option<chalk_solve::Solution> {
        let context = ChalkContext { db, krate: self.krate };
        debug!("solve goal: {:?}", goal);
-        let solution = self.inner.lock().solve(&context, goal);
+        let mut solver = match self.inner.lock() {
+            Ok(it) => it,
+            // Our cancellation works via unwinding, but, as chalk is not
+            // panic-safe, we need to make sure to propagate the cancellation.
+            // Ideally, we should also make chalk panic-safe.
+            Err(_) => ra_db::Canceled::throw(),
+        };
+        let solution = solver.solve(&context, goal);
        debug!("solve({:?}) => {:?}", goal, solution);
        solution
    }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 538b4d3ec..2642a54bf 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -10,17 +10,13 @@ use chalk_ir::{
 use chalk_rust_ir::{AssociatedTyDatum, ImplDatum, StructDatum, TraitDatum};
 use ra_db::salsa::{InternId, InternKey};
-use test_utils::tested_by;
 use super::{Canonical, ChalkContext, Impl, Obligation};
 use crate::{
    db::HirDatabase,
    generics::GenericDef,
    ty::display::HirDisplay,
-    ty::{
+    ty::{ApplicationTy, GenericPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk},
-        ApplicationTy, CallableDef, GenericPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor,
-        TypeWalk,
-    },
    AssocItem, Crate, HasGenericParams, ImplBlock, Trait, TypeAlias,
 };
@@ -124,14 +120,15 @@ impl ToChalk for Substs {
    }
    fn from_chalk(db: &impl HirDatabase, parameters: Vec<chalk_ir::Parameter>) -> Substs {
-        parameters
+        let tys = parameters
            .into_iter()
            .map(|p| match p {
                chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
                chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
            })
            .collect::<Vec<_>>()
-            .into()
+            .into();
+        Substs(tys)
    }
 }
@@ -539,60 +536,18 @@ pub(crate) fn struct_datum_query(
    struct_id: chalk_ir::StructId,
 ) -> Arc<StructDatum> {
    debug!("struct_datum {:?}", struct_id);
-    let type_ctor = from_chalk(db, struct_id);
+    let type_ctor: TypeCtor = from_chalk(db, struct_id);
    debug!("struct {:?} = {:?}", struct_id, type_ctor);
-    // FIXME might be nicer if we can create a fake GenericParams for the TypeCtor
+    let num_params = type_ctor.num_ty_params(db);
-    // FIXME extract this to a method on Ty
+    let upstream = type_ctor.krate(db) != Some(krate);
-    let (num_params, where_clauses, upstream) = match type_ctor {
+    let where_clauses = type_ctor
-        TypeCtor::Bool
+        .as_generic_def()
-        | TypeCtor::Char
+        .map(|generic_def| {
-        | TypeCtor::Int(_)
-        | TypeCtor::Float(_)
-        | TypeCtor::Never
-        | TypeCtor::Str => (0, vec![], true),
-        TypeCtor::Slice | TypeCtor::Array | TypeCtor::RawPtr(_) | TypeCtor::Ref(_) => {
-            (1, vec![], true)
-        }
-        TypeCtor::FnPtr { num_args } => (num_args as usize + 1, vec![], true),
-        TypeCtor::Tuple { cardinality } => (cardinality as usize, vec![], true),
-        TypeCtor::FnDef(callable) => {
-            tested_by!(trait_resolution_on_fn_type);
-            let upstream = match callable {
-                CallableDef::Function(f) => f.module(db).krate(db),
-                CallableDef::Struct(s) => s.module(db).krate(db),
-                CallableDef::EnumVariant(v) => v.parent_enum(db).module(db).krate(db),
-            } != Some(krate);
-            let generic_def: GenericDef = callable.into();
            let generic_params = generic_def.generic_params(db);
            let bound_vars = Substs::bound_vars(&generic_params);
-            let where_clauses = convert_where_clauses(db, generic_def, &bound_vars);
+            convert_where_clauses(db, generic_def, &bound_vars)
-            (generic_params.count_params_including_parent(), where_clauses, upstream)
+        })
-        }
+        .unwrap_or_else(Vec::new);
-        TypeCtor::Adt(adt) => {
-            let generic_params = adt.generic_params(db);
-            let bound_vars = Substs::bound_vars(&generic_params);
-            let where_clauses = convert_where_clauses(db, adt.into(), &bound_vars);
-            (
-                generic_params.count_params_including_parent(),
-                where_clauses,
-                adt.krate(db) != Some(krate),
-            )
-        }
-        TypeCtor::AssociatedType(type_alias) => {
-            let generic_params = type_alias.generic_params(db);
-            let bound_vars = Substs::bound_vars(&generic_params);
-            let where_clauses = convert_where_clauses(db, type_alias.into(), &bound_vars);
-            (
-                generic_params.count_params_including_parent(),
-                where_clauses,
-                type_alias.krate(db) != Some(krate),
-            )
-        }
-        TypeCtor::Closure { def, .. } => {
-            let upstream = def.krate(db) != Some(krate);
-            (1, vec![], upstream)
-        }
-    };
    let flags = chalk_rust_ir::StructFlags {
        upstream,
        // FIXME set fundamental flag correctly
@@ -729,17 +684,20 @@ fn closure_fn_trait_impl_datum(
    let arg_ty = Ty::apply(
        TypeCtor::Tuple { cardinality: num_args },
-        (0..num_args).map(|i| Ty::Bound(i.into())).collect::<Vec<_>>().into(),
+        Substs::builder(num_args as usize).fill_with_bound_vars(0).build(),
    );
    let output_ty = Ty::Bound(num_args.into());
    let sig_ty = Ty::apply(
        TypeCtor::FnPtr { num_args },
-        (0..num_args + 1).map(|i| Ty::Bound(i.into())).collect::<Vec<_>>().into(),
+        Substs::builder(num_args as usize + 1).fill_with_bound_vars(0).build(),
    );
    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
-    let trait_ref = TraitRef { trait_, substs: vec![self_ty, arg_ty].into() };
+    let trait_ref = TraitRef {
+        trait_,
+        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
+    };
    let output_ty_id = fn_once_trait.associated_type_by_name(db, &crate::name::OUTPUT_TYPE)?;
diff --git a/crates/ra_hir/src/type_ref.rs b/crates/ra_hir/src/type_ref.rs
index bc8acc7ee..2cf06b250 100644
--- a/crates/ra_hir/src/type_ref.rs
+++ b/crates/ra_hir/src/type_ref.rs
@@ -72,6 +72,7 @@ impl TypeRef {
            }
            ast::TypeRef::NeverType(..) => TypeRef::Never,
            ast::TypeRef::PathType(inner) => {
+                // FIXME: Use `Path::from_src`
                inner.path().and_then(Path::from_ast).map(TypeRef::Path).unwrap_or(TypeRef::Error)
            }
            ast::TypeRef::PointerType(inner) => {
@@ -141,6 +142,7 @@ impl TypeBound {
                    Some(p) => p,
                    None => return TypeBound::Error,
                };
+                // FIXME: Use `Path::from_src`
                let path = match Path::from_ast(path) {
                    Some(p) => p,
                    None => return TypeBound::Error,
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide_api/Cargo.toml
index 6bbf9d5dd..f919a2d61 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide_api/Cargo.toml
@@ -23,6 +23,7 @@ rand = { version = "0.7.0", features = ["small_rng"] }
 ra_syntax = { path = "../ra_syntax" }
 ra_text_edit = { path = "../ra_text_edit" }
 ra_db = { path = "../ra_db" }
+ra_cfg = { path = "../ra_cfg" }
 ra_fmt = { path = "../ra_fmt" }
 ra_prof = { path = "../ra_prof" }
 hir = { path = "../ra_hir", package = "ra_hir" }
diff --git a/crates/ra_ide_api/src/assists.rs b/crates/ra_ide_api/src/assists.rs
index e3d1ac529..e00589733 100644
--- a/crates/ra_ide_api/src/assists.rs
+++ b/crates/ra_ide_api/src/assists.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::{FilePosition, FileRange};
 use crate::{db::RootDatabase, SourceChange, SourceFileEdit};
diff --git a/crates/ra_ide_api/src/call_info.rs b/crates/ra_ide_api/src/call_info.rs
index d5e116526..7d18be483 100644
--- a/crates/ra_ide_api/src/call_info.rs
+++ b/crates/ra_ide_api/src/call_info.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::SourceDatabase;
 use ra_syntax::{
    algo::find_node_at_offset,
diff --git a/crates/ra_ide_api/src/change.rs b/crates/ra_ide_api/src/change.rs
index 981851829..09913787b 100644
--- a/crates/ra_ide_api/src/change.rs
+++ b/crates/ra_ide_api/src/change.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{fmt, sync::Arc, time};
 use ra_db::{
diff --git a/crates/ra_ide_api/src/completion.rs b/crates/ra_ide_api/src/completion.rs
index 0ad414831..abe1f36ce 100644
--- a/crates/ra_ide_api/src/completion.rs
+++ b/crates/ra_ide_api/src/completion.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod completion_item;
 mod completion_context;
 mod presentation;
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index 9e64c8659..28c8324d0 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{Adt, Ty, TypeCtor};
 use crate::completion::completion_item::CompletionKind;
diff --git a/crates/ra_ide_api/src/completion/complete_fn_param.rs b/crates/ra_ide_api/src/completion/complete_fn_param.rs
index 6639b6fff..3e936e3ec 100644
--- a/crates/ra_ide_api/src/completion/complete_fn_param.rs
+++ b/crates/ra_ide_api/src/completion/complete_fn_param.rs
@@ -1,7 +1,6 @@
-use ra_syntax::{
+//! FIXME: write short doc here
-    algo::visit::{visitor_ctx, VisitorCtx},
-    ast, AstNode,
+use ra_syntax::{ast, match_ast, AstNode};
-};
 use rustc_hash::FxHashMap;
 use crate::completion::{CompletionContext, CompletionItem, CompletionKind, Completions};
@@ -17,10 +16,13 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
    let mut params = FxHashMap::default();
    for node in ctx.token.parent().ancestors() {
-        let _ = visitor_ctx(&mut params)
+        match_ast! {
-            .visit::<ast::SourceFile, _>(process)
+            match node {
-            .visit::<ast::ItemList, _>(process)
+                ast::SourceFile(it) => { process(it, &mut params) },
-            .accept(&node);
+                ast::ItemList(it) => { process(it, &mut params) },
+                _ => (),
+            }
+        }
    }
    params
        .into_iter()
diff --git a/crates/ra_ide_api/src/completion/complete_keyword.rs b/crates/ra_ide_api/src/completion/complete_keyword.rs
index c527a9f63..48c688a08 100644
--- a/crates/ra_ide_api/src/completion/complete_keyword.rs
+++ b/crates/ra_ide_api/src/completion/complete_keyword.rs
@@ -1,7 +1,8 @@
+//! FIXME: write short doc here
 use ra_syntax::{
-    algo::visit::{visitor, Visitor},
    ast::{self, LoopBodyOwner},
-    AstNode,
+    match_ast, AstNode,
    SyntaxKind::*,
    SyntaxToken,
 };
@@ -82,12 +83,15 @@ fn is_in_loop_body(leaf: &SyntaxToken) -> bool {
        if node.kind() == FN_DEF || node.kind() == LAMBDA_EXPR {
            break;
        }
-        let loop_body = visitor()
+        let loop_body = match_ast! {
-            .visit::<ast::ForExpr, _>(|it| it.loop_body())
+            match node {
-            .visit::<ast::WhileExpr, _>(|it| it.loop_body())
+                ast::ForExpr(it) => { it.loop_body() },
-            .visit::<ast::LoopExpr, _>(|it| it.loop_body())
+                ast::WhileExpr(it) => { it.loop_body() },
-            .accept(&node);
+                ast::LoopExpr(it) => { it.loop_body() },
-        if let Some(Some(body)) = loop_body {
+                _ => None,
+            }
+        };
+        if let Some(body) = loop_body {
            if leaf.text_range().is_subrange(&body.syntax().text_range()) {
                return true;
            }
diff --git a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs b/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
index 0cbe4abf7..d808b2357 100644
--- a/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
+++ b/crates/ra_ide_api/src/completion/complete_macro_in_item_position.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::completion::{CompletionContext, Completions};
 pub(super) fn complete_macro_in_item_position(acc: &mut Completions, ctx: &CompletionContext) {
diff --git a/crates/ra_ide_api/src/completion/complete_path.rs b/crates/ra_ide_api/src/completion/complete_path.rs
index e9fec54d8..e01197fe4 100644
--- a/crates/ra_ide_api/src/completion/complete_path.rs
+++ b/crates/ra_ide_api/src/completion/complete_path.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{Adt, Either, PathResolution};
 use ra_syntax::AstNode;
 use test_utils::tested_by;
diff --git a/crates/ra_ide_api/src/completion/complete_pattern.rs b/crates/ra_ide_api/src/completion/complete_pattern.rs
index c17b5b7ee..513ad6e5f 100644
--- a/crates/ra_ide_api/src/completion/complete_pattern.rs
+++ b/crates/ra_ide_api/src/completion/complete_pattern.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::completion::{CompletionContext, Completions};
 /// Completes constats and paths in patterns.
diff --git a/crates/ra_ide_api/src/completion/complete_postfix.rs b/crates/ra_ide_api/src/completion/complete_postfix.rs
index 3970d1af3..445a02676 100644
--- a/crates/ra_ide_api/src/completion/complete_postfix.rs
+++ b/crates/ra_ide_api/src/completion/complete_postfix.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{
    completion::{
        completion_context::CompletionContext,
diff --git a/crates/ra_ide_api/src/completion/complete_record_literal.rs b/crates/ra_ide_api/src/completion/complete_record_literal.rs
index ed4029964..4406695d5 100644
--- a/crates/ra_ide_api/src/completion/complete_record_literal.rs
+++ b/crates/ra_ide_api/src/completion/complete_record_literal.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::Substs;
 use crate::completion::{CompletionContext, Completions};
diff --git a/crates/ra_ide_api/src/completion/complete_record_pattern.rs b/crates/ra_ide_api/src/completion/complete_record_pattern.rs
index 70716b3d6..d20fa796c 100644
--- a/crates/ra_ide_api/src/completion/complete_record_pattern.rs
+++ b/crates/ra_ide_api/src/completion/complete_record_pattern.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::Substs;
 use crate::completion::{CompletionContext, Completions};
diff --git a/crates/ra_ide_api/src/completion/complete_scope.rs b/crates/ra_ide_api/src/completion/complete_scope.rs
index cb70a1f21..515a6285c 100644
--- a/crates/ra_ide_api/src/completion/complete_scope.rs
+++ b/crates/ra_ide_api/src/completion/complete_scope.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_assists::auto_import_text_edit;
 use ra_syntax::{ast, AstNode, SmolStr};
 use ra_text_edit::TextEditBuilder;
diff --git a/crates/ra_ide_api/src/completion/complete_snippet.rs b/crates/ra_ide_api/src/completion/complete_snippet.rs
index b06221c2a..2df79b6c3 100644
--- a/crates/ra_ide_api/src/completion/complete_snippet.rs
+++ b/crates/ra_ide_api/src/completion/complete_snippet.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::completion::{
    completion_item::Builder, CompletionContext, CompletionItem, CompletionItemKind,
    CompletionKind, Completions,
diff --git a/crates/ra_ide_api/src/completion/completion_context.rs b/crates/ra_ide_api/src/completion/completion_context.rs
index 57542152f..e9ad06965 100644
--- a/crates/ra_ide_api/src/completion/completion_context.rs
+++ b/crates/ra_ide_api/src/completion/completion_context.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_syntax::{
    algo::{find_covering_element, find_node_at_offset},
    ast, AstNode, Parse, SourceFile,
diff --git a/crates/ra_ide_api/src/completion/completion_item.rs b/crates/ra_ide_api/src/completion/completion_item.rs
index d787bb69e..b1f0390ec 100644
--- a/crates/ra_ide_api/src/completion/completion_item.rs
+++ b/crates/ra_ide_api/src/completion/completion_item.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 use hir::Documentation;
diff --git a/crates/ra_ide_api/src/completion/presentation.rs b/crates/ra_ide_api/src/completion/presentation.rs
index b8aa433c1..48028a2f9 100644
--- a/crates/ra_ide_api/src/completion/presentation.rs
+++ b/crates/ra_ide_api/src/completion/presentation.rs
@@ -1,4 +1,5 @@
 //! This modules takes care of rendering various definitions as completion items.
 use hir::{Docs, HasSource, HirDisplay, ScopeDef, Ty, TypeWalk};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index afd9022ce..ea0714add 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
 use ra_db::{
diff --git a/crates/ra_ide_api/src/diagnostics.rs b/crates/ra_ide_api/src/diagnostics.rs
index 144bc0a70..0435188c8 100644
--- a/crates/ra_ide_api/src/diagnostics.rs
+++ b/crates/ra_ide_api/src/diagnostics.rs
@@ -1,11 +1,13 @@
+//! FIXME: write short doc here
 use std::cell::RefCell;
 use hir::diagnostics::{AstDiagnostic, Diagnostic as _, DiagnosticSink};
 use itertools::Itertools;
-use ra_assists::ast_editor::AstEditor;
 use ra_db::SourceDatabase;
 use ra_prof::profile;
 use ra_syntax::{
+    algo,
    ast::{self, make, AstNode},
    Location, SyntaxNode, TextRange, T,
 };
@@ -56,15 +58,15 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
        })
    })
    .on::<hir::diagnostics::MissingFields, _>(|d| {
-        let node = d.ast(db);
+        let mut field_list = d.ast(db);
-        let mut ast_editor = AstEditor::new(node);
        for f in d.missed_fields.iter() {
            let field = make::record_field(make::name_ref(&f.to_string()), Some(make::expr_unit()));
-            ast_editor.append_field(&field);
+            field_list = field_list.append_field(&field);
        }
        let mut builder = TextEditBuilder::default();
-        ast_editor.into_text_edit(&mut builder);
+        algo::diff(&d.ast(db).syntax(), &field_list.syntax()).into_text_edit(&mut builder);
        let fix =
            SourceChange::source_file_edit_from("fill struct fields", file_id, builder.finish());
        res.borrow_mut().push(Diagnostic {
diff --git a/crates/ra_ide_api/src/display/function_signature.rs b/crates/ra_ide_api/src/display/function_signature.rs
index 644a4532b..43f022ccd 100644
--- a/crates/ra_ide_api/src/display/function_signature.rs
+++ b/crates/ra_ide_api/src/display/function_signature.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt::{self, Display};
 use hir::{Docs, Documentation, HasSource};
diff --git a/crates/ra_ide_api/src/display/navigation_target.rs b/crates/ra_ide_api/src/display/navigation_target.rs
index d3e774bd0..d0b1a8a2a 100644
--- a/crates/ra_ide_api/src/display/navigation_target.rs
+++ b/crates/ra_ide_api/src/display/navigation_target.rs
@@ -1,9 +1,10 @@
+//! FIXME: write short doc here
 use hir::{AssocItem, FieldSource, HasSource, ModuleSource};
 use ra_db::{FileId, SourceDatabase};
 use ra_syntax::{
-    algo::visit::{visitor, Visitor},
    ast::{self, DocCommentsOwner},
-    AstNode, AstPtr, SmolStr,
+    match_ast, AstNode, AstPtr, SmolStr,
    SyntaxKind::{self, NAME},
    SyntaxNode, TextRange,
 };
@@ -306,19 +307,22 @@ pub(crate) fn docs_from_symbol(db: &RootDatabase, symbol: &FileSymbol) -> Option
    let parse = db.parse(symbol.file_id);
    let node = symbol.ptr.to_node(parse.tree().syntax());
-    visitor()
+    match_ast! {
-        .visit(|it: ast::FnDef| it.doc_comment_text())
+        match node {
-        .visit(|it: ast::StructDef| it.doc_comment_text())
+            ast::FnDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::EnumDef| it.doc_comment_text())
+            ast::StructDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::TraitDef| it.doc_comment_text())
+            ast::EnumDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::Module| it.doc_comment_text())
+            ast::TraitDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::TypeAliasDef| it.doc_comment_text())
+            ast::Module(it) => { it.doc_comment_text() },
-        .visit(|it: ast::ConstDef| it.doc_comment_text())
+            ast::TypeAliasDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::StaticDef| it.doc_comment_text())
+            ast::ConstDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::RecordFieldDef| it.doc_comment_text())
+            ast::StaticDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::EnumVariant| it.doc_comment_text())
+            ast::RecordFieldDef(it) => { it.doc_comment_text() },
-        .visit(|it: ast::MacroCall| it.doc_comment_text())
+            ast::EnumVariant(it) => { it.doc_comment_text() },
-        .accept(&node)?
+            ast::MacroCall(it) => { it.doc_comment_text() },
+            _ => None,
+        }
+    }
 }
 /// Get a description of a symbol.
@@ -328,16 +332,19 @@ pub(crate) fn description_from_symbol(db: &RootDatabase, symbol: &FileSymbol) ->
    let parse = db.parse(symbol.file_id);
    let node = symbol.ptr.to_node(parse.tree().syntax());
-    visitor()
+    match_ast! {
-        .visit(|node: ast::FnDef| node.short_label())
+        match node {
-        .visit(|node: ast::StructDef| node.short_label())
+            ast::FnDef(it) => { it.short_label() },
-        .visit(|node: ast::EnumDef| node.short_label())
+            ast::StructDef(it) => { it.short_label() },
-        .visit(|node: ast::TraitDef| node.short_label())
+            ast::EnumDef(it) => { it.short_label() },
-        .visit(|node: ast::Module| node.short_label())
+            ast::TraitDef(it) => { it.short_label() },
-        .visit(|node: ast::TypeAliasDef| node.short_label())
+            ast::Module(it) => { it.short_label() },
-        .visit(|node: ast::ConstDef| node.short_label())
+            ast::TypeAliasDef(it) => { it.short_label() },
-        .visit(|node: ast::StaticDef| node.short_label())
+            ast::ConstDef(it) => { it.short_label() },
-        .visit(|node: ast::RecordFieldDef| node.short_label())
+            ast::StaticDef(it) => { it.short_label() },
-        .visit(|node: ast::EnumVariant| node.short_label())
+            ast::RecordFieldDef(it) => { it.short_label() },
-        .accept(&node)?
+            ast::EnumVariant(it) => { it.short_label() },
+            _ => None,
+        }
+    }
 }
diff --git a/crates/ra_ide_api/src/display/short_label.rs b/crates/ra_ide_api/src/display/short_label.rs
index b16d504e1..5d2bce3d2 100644
--- a/crates/ra_ide_api/src/display/short_label.rs
+++ b/crates/ra_ide_api/src/display/short_label.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use format_buf::format;
 use ra_syntax::ast::{self, AstNode, NameOwner, TypeAscriptionOwner, VisibilityOwner};
diff --git a/crates/ra_ide_api/src/display/structure.rs b/crates/ra_ide_api/src/display/structure.rs
index be042ed17..ddd8b7b20 100644
--- a/crates/ra_ide_api/src/display/structure.rs
+++ b/crates/ra_ide_api/src/display/structure.rs
@@ -1,9 +1,10 @@
+//! FIXME: write short doc here
 use crate::TextRange;
 use ra_syntax::{
-    algo::visit::{visitor, Visitor},
    ast::{self, AttrsOwner, NameOwner, TypeAscriptionOwner, TypeParamsOwner},
-    AstNode, SourceFile, SyntaxKind, SyntaxNode, WalkEvent,
+    match_ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, WalkEvent,
 };
 #[derive(Debug, Clone)]
@@ -77,7 +78,7 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
            node_range: node.syntax().text_range(),
            kind: node.syntax().kind(),
            detail,
-            deprecated: node.attrs().filter_map(|x| x.as_named()).any(|x| x == "deprecated"),
+            deprecated: node.attrs().filter_map(|x| x.simple_name()).any(|x| x == "deprecated"),
        })
    }
@@ -99,63 +100,66 @@ fn structure_node(node: &SyntaxNode) -> Option<StructureNode> {
        })
    }
-    visitor()
+    match_ast! {
-        .visit(|fn_def: ast::FnDef| {
+        match node {
-            let mut detail = String::from("fn");
+            ast::FnDef(it) => {
-            if let Some(type_param_list) = fn_def.type_param_list() {
+                let mut detail = String::from("fn");
-                collapse_ws(type_param_list.syntax(), &mut detail);
+                if let Some(type_param_list) = it.type_param_list() {
-            }
+                    collapse_ws(type_param_list.syntax(), &mut detail);
-            if let Some(param_list) = fn_def.param_list() {
+                }
-                collapse_ws(param_list.syntax(), &mut detail);
+                if let Some(param_list) = it.param_list() {
-            }
+                    collapse_ws(param_list.syntax(), &mut detail);
-            if let Some(ret_type) = fn_def.ret_type() {
+                }
-                detail.push_str(" ");
+                if let Some(ret_type) = it.ret_type() {
-                collapse_ws(ret_type.syntax(), &mut detail);
+                    detail.push_str(" ");
-            }
+                    collapse_ws(ret_type.syntax(), &mut detail);
-            decl_with_detail(fn_def, Some(detail))
-        })
-        .visit(decl::<ast::StructDef>)
-        .visit(decl::<ast::EnumDef>)
-        .visit(decl::<ast::EnumVariant>)
-        .visit(decl::<ast::TraitDef>)
-        .visit(decl::<ast::Module>)
-        .visit(|td: ast::TypeAliasDef| {
-            let ty = td.type_ref();
-            decl_with_type_ref(td, ty)
-        })
-        .visit(decl_with_ascription::<ast::RecordFieldDef>)
-        .visit(decl_with_ascription::<ast::ConstDef>)
-        .visit(decl_with_ascription::<ast::StaticDef>)
-        .visit(|im: ast::ImplBlock| {
-            let target_type = im.target_type()?;
-            let target_trait = im.target_trait();
-            let label = match target_trait {
-                None => format!("impl {}", target_type.syntax().text()),
-                Some(t) => {
-                    format!("impl {} for {}", t.syntax().text(), target_type.syntax().text(),)
                }
-            };
-            let node = StructureNode {
+                decl_with_detail(it, Some(detail))
-                parent: None,
+            },
-                label,
+            ast::StructDef(it) => { decl(it) },
-                navigation_range: target_type.syntax().text_range(),
+            ast::EnumDef(it) => { decl(it) },
-                node_range: im.syntax().text_range(),
+            ast::EnumVariant(it) => { decl(it) },
-                kind: im.syntax().kind(),
+            ast::TraitDef(it) => { decl(it) },
-                detail: None,
+            ast::Module(it) => { decl(it) },
-                deprecated: false,
+            ast::TypeAliasDef(it) => {
-            };
+                let ty = it.type_ref();
-            Some(node)
+                decl_with_type_ref(it, ty)
-        })
+            },
-        .visit(|mc: ast::MacroCall| {
+            ast::RecordFieldDef(it) => { decl_with_ascription(it) },
-            let first_token = mc.syntax().first_token().unwrap();
+            ast::ConstDef(it) => { decl_with_ascription(it) },
-            if first_token.text().as_str() != "macro_rules" {
+            ast::StaticDef(it) => { decl_with_ascription(it) },
-                return None;
+            ast::ImplBlock(it) => {
-            }
+                let target_type = it.target_type()?;
-            decl(mc)
+                let target_trait = it.target_trait();
-        })
+                let label = match target_trait {
-        .accept(&node)?
+                    None => format!("impl {}", target_type.syntax().text()),
+                    Some(t) => {
+                        format!("impl {} for {}", t.syntax().text(), target_type.syntax().text(),)
+                    }
+                };
+                let node = StructureNode {
+                    parent: None,
+                    label,
+                    navigation_range: target_type.syntax().text_range(),
+                    node_range: it.syntax().text_range(),
+                    kind: it.syntax().kind(),
+                    detail: None,
+                    deprecated: false,
+                };
+                Some(node)
+            },
+            ast::MacroCall(it) => {
+                let first_token = it.syntax().first_token().unwrap();
+                if first_token.text().as_str() != "macro_rules" {
+                    return None;
+                }
+                decl(it)
+            },
+            _ => None,
+        }
+    }
 }
 #[cfg(test)]
diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide_api/src/extend_selection.rs
index e990eb0d1..33fefb541 100644
--- a/crates/ra_ide_api/src/extend_selection.rs
+++ b/crates/ra_ide_api/src/extend_selection.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::SourceDatabase;
 use ra_syntax::{
    algo::find_covering_element,
diff --git a/crates/ra_ide_api/src/feature_flags.rs b/crates/ra_ide_api/src/feature_flags.rs
index 9f82ac71c..d3ca7be03 100644
--- a/crates/ra_ide_api/src/feature_flags.rs
+++ b/crates/ra_ide_api/src/feature_flags.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use rustc_hash::FxHashMap;
 /// Feature flags hold fine-grained toggles for all *user-visible* features of
diff --git a/crates/ra_ide_api/src/folding_ranges.rs b/crates/ra_ide_api/src/folding_ranges.rs
index 79fadcc5d..4eeb76d14 100644
--- a/crates/ra_ide_api/src/folding_ranges.rs
+++ b/crates/ra_ide_api/src/folding_ranges.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use rustc_hash::FxHashSet;
 use ra_syntax::{
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index bc8863dad..41a88314f 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -1,11 +1,10 @@
+//! FIXME: write short doc here
 use ra_db::{FileId, SourceDatabase};
 use ra_syntax::{
-    algo::{
+    algo::find_node_at_offset,
-        find_node_at_offset,
-        visit::{visitor, Visitor},
-    },
    ast::{self, DocCommentsOwner},
-    AstNode, SyntaxNode,
+    match_ast, AstNode, SyntaxNode,
 };
 use crate::{
@@ -112,91 +111,99 @@ pub(crate) fn name_definition(
 }
 fn named_target(file_id: FileId, node: &SyntaxNode) -> Option<NavigationTarget> {
-    visitor()
+    match_ast! {
-        .visit(|node: ast::StructDef| {
+        match node {
-            NavigationTarget::from_named(
+            ast::StructDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::EnumDef| {
+            },
-            NavigationTarget::from_named(
+            ast::EnumDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::EnumVariant| {
+            },
-            NavigationTarget::from_named(
+            ast::EnumVariant(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::FnDef| {
+            },
-            NavigationTarget::from_named(
+            ast::FnDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::TypeAliasDef| {
+            },
-            NavigationTarget::from_named(
+            ast::TypeAliasDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::ConstDef| {
+            },
-            NavigationTarget::from_named(
+            ast::ConstDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::StaticDef| {
+            },
-            NavigationTarget::from_named(
+            ast::StaticDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::TraitDef| {
+            },
-            NavigationTarget::from_named(
+            ast::TraitDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::RecordFieldDef| {
+            },
-            NavigationTarget::from_named(
+            ast::RecordFieldDef(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::Module| {
+            },
-            NavigationTarget::from_named(
+            ast::Module(it) => {
-                file_id,
+                Some(NavigationTarget::from_named(
-                &node,
+                    file_id,
-                node.doc_comment_text(),
+                    &it,
-                node.short_label(),
+                    it.doc_comment_text(),
-            )
+                    it.short_label(),
-        })
+                ))
-        .visit(|node: ast::MacroCall| {
+            },
-            NavigationTarget::from_named(file_id, &node, node.doc_comment_text(), None)
+            ast::MacroCall(it) => {
-        })
+                Some(NavigationTarget::from_named(
-        .accept(node)
+                    file_id,
+                    &it,
+                    it.doc_comment_text(),
+                    None,
+                ))
+            },
+            _ => None,
+        }
+    }
 }
 #[cfg(test)]
diff --git a/crates/ra_ide_api/src/goto_type_definition.rs b/crates/ra_ide_api/src/goto_type_definition.rs
index 72884e5ca..059d80524 100644
--- a/crates/ra_ide_api/src/goto_type_definition.rs
+++ b/crates/ra_ide_api/src/goto_type_definition.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::SourceDatabase;
 use ra_syntax::{ast, AstNode};
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 655bcdb16..24b161c5c 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -1,12 +1,11 @@
+//! FIXME: write short doc here
 use hir::{Adt, HasSource, HirDisplay};
 use ra_db::SourceDatabase;
 use ra_syntax::{
-    algo::{
+    algo::{ancestors_at_offset, find_covering_element, find_node_at_offset},
-        ancestors_at_offset, find_covering_element, find_node_at_offset,
-        visit::{visitor, Visitor},
-    },
    ast::{self, DocCommentsOwner},
-    AstNode,
+    match_ast, AstNode,
 };
 use crate::{
@@ -176,37 +175,45 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
        }
    } else if let Some(name) = find_node_at_offset::<ast::Name>(file.syntax(), position.offset) {
        if let Some(parent) = name.syntax().parent() {
-            let text = visitor()
+            let text = match_ast! {
-                .visit(|node: ast::StructDef| {
+                match parent {
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    ast::StructDef(it) => {
-                })
+                        hover_text(it.doc_comment_text(), it.short_label())
-                .visit(|node: ast::EnumDef| hover_text(node.doc_comment_text(), node.short_label()))
+                    },
-                .visit(|node: ast::EnumVariant| {
+                    ast::EnumDef(it) => {
-                    hover_text(node.doc_comment_text(), node.short_label())
+                        hover_text(it.doc_comment_text(), it.short_label())
-                })
+                    },
-                .visit(|node: ast::FnDef| hover_text(node.doc_comment_text(), node.short_label()))
+                    ast::EnumVariant(it) => {
-                .visit(|node: ast::TypeAliasDef| {
+                        hover_text(it.doc_comment_text(), it.short_label())
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    },
-                })
+                    ast::FnDef(it) => {
-                .visit(|node: ast::ConstDef| {
+                        hover_text(it.doc_comment_text(), it.short_label())
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    },
-                })
+                    ast::TypeAliasDef(it) => {
-                .visit(|node: ast::StaticDef| {
+                        hover_text(it.doc_comment_text(), it.short_label())
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    },
-                })
+                    ast::ConstDef(it) => {
-                .visit(|node: ast::TraitDef| {
+                        hover_text(it.doc_comment_text(), it.short_label())
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    },
-                })
+                    ast::StaticDef(it) => {
-                .visit(|node: ast::RecordFieldDef| {
+                        hover_text(it.doc_comment_text(), it.short_label())
-                    hover_text(node.doc_comment_text(), node.short_label())
+                    },
-                })
+                    ast::TraitDef(it) => {
-                .visit(|node: ast::Module| hover_text(node.doc_comment_text(), node.short_label()))
+                        hover_text(it.doc_comment_text(), it.short_label())
-                .visit(|node: ast::MacroCall| hover_text(node.doc_comment_text(), None))
+                    },
-                .accept(&parent);
+                    ast::RecordFieldDef(it) => {
+                        hover_text(it.doc_comment_text(), it.short_label())
-            if let Some(text) = text {
+                    },
-                res.extend(text);
+                    ast::Module(it) => {
-            }
+                        hover_text(it.doc_comment_text(), it.short_label())
+                    },
+                    ast::MacroCall(it) => {
+                        hover_text(it.doc_comment_text(), None)
+                    },
+                    _ => None,
+                }
+            };
+            res.extend(text);
        }
        if !res.is_empty() && range.is_none() {
diff --git a/crates/ra_ide_api/src/impls.rs b/crates/ra_ide_api/src/impls.rs
index f57f9a21b..7fc1b1efa 100644
--- a/crates/ra_ide_api/src/impls.rs
+++ b/crates/ra_ide_api/src/impls.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{db::HirDatabase, ApplicationTy, FromSource, Ty, TypeCtor};
 use ra_db::SourceDatabase;
 use ra_syntax::{algo::find_node_at_offset, ast, AstNode};
diff --git a/crates/ra_ide_api/src/inlay_hints.rs b/crates/ra_ide_api/src/inlay_hints.rs
index 16bdcf9d1..f1c0dc164 100644
--- a/crates/ra_ide_api/src/inlay_hints.rs
+++ b/crates/ra_ide_api/src/inlay_hints.rs
@@ -1,9 +1,10 @@
+//! FIXME: write short doc here
 use crate::{db::RootDatabase, FileId};
 use hir::{HirDisplay, SourceAnalyzer, Ty};
 use ra_syntax::{
-    algo::visit::{visitor, Visitor},
    ast::{self, AstNode, TypeAscriptionOwner},
-    SmolStr, SourceFile, SyntaxKind, SyntaxNode, TextRange,
+    match_ast, SmolStr, SourceFile, SyntaxKind, SyntaxNode, TextRange,
 };
 #[derive(Debug, PartialEq, Eq)]
@@ -31,55 +32,58 @@ fn get_inlay_hints(
    file_id: FileId,
    node: &SyntaxNode,
 ) -> Option<Vec<InlayHint>> {
-    visitor()
+    match_ast! {
-        .visit(|let_statement: ast::LetStmt| {
+        match node {
-            if let_statement.ascribed_type().is_some() {
+            ast::LetStmt(it) => {
-                return None;
+                if it.ascribed_type().is_some() {
-            }
+                    return None;
-            let pat = let_statement.pat()?;
+                }
-            let analyzer = SourceAnalyzer::new(db, file_id, let_statement.syntax(), None);
+                let pat = it.pat()?;
-            Some(get_pat_type_hints(db, &analyzer, pat, false))
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-        })
+                Some(get_pat_type_hints(db, &analyzer, pat, false))
-        .visit(|closure_parameter: ast::LambdaExpr| {
+            },
-            let analyzer = SourceAnalyzer::new(db, file_id, closure_parameter.syntax(), None);
+            ast::LambdaExpr(it) => {
-            closure_parameter.param_list().map(|param_list| {
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-                param_list
+                it.param_list().map(|param_list| {
-                    .params()
+                    param_list
-                    .filter(|closure_param| closure_param.ascribed_type().is_none())
+                        .params()
-                    .filter_map(|closure_param| closure_param.pat())
+                        .filter(|closure_param| closure_param.ascribed_type().is_none())
-                    .map(|root_pat| get_pat_type_hints(db, &analyzer, root_pat, false))
+                        .filter_map(|closure_param| closure_param.pat())
-                    .flatten()
+                        .map(|root_pat| get_pat_type_hints(db, &analyzer, root_pat, false))
-                    .collect()
+                        .flatten()
-            })
+                        .collect()
-        })
+                })
-        .visit(|for_expression: ast::ForExpr| {
+            },
-            let pat = for_expression.pat()?;
+            ast::ForExpr(it) => {
-            let analyzer = SourceAnalyzer::new(db, file_id, for_expression.syntax(), None);
+                let pat = it.pat()?;
-            Some(get_pat_type_hints(db, &analyzer, pat, false))
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-        })
+                Some(get_pat_type_hints(db, &analyzer, pat, false))
-        .visit(|if_expr: ast::IfExpr| {
+            },
-            let pat = if_expr.condition()?.pat()?;
+            ast::IfExpr(it) => {
-            let analyzer = SourceAnalyzer::new(db, file_id, if_expr.syntax(), None);
+                let pat = it.condition()?.pat()?;
-            Some(get_pat_type_hints(db, &analyzer, pat, true))
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-        })
+                Some(get_pat_type_hints(db, &analyzer, pat, true))
-        .visit(|while_expr: ast::WhileExpr| {
+            },
-            let pat = while_expr.condition()?.pat()?;
+            ast::WhileExpr(it) => {
-            let analyzer = SourceAnalyzer::new(db, file_id, while_expr.syntax(), None);
+                let pat = it.condition()?.pat()?;
-            Some(get_pat_type_hints(db, &analyzer, pat, true))
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-        })
+                Some(get_pat_type_hints(db, &analyzer, pat, true))
-        .visit(|match_arm_list: ast::MatchArmList| {
+            },
-            let analyzer = SourceAnalyzer::new(db, file_id, match_arm_list.syntax(), None);
+            ast::MatchArmList(it) => {
-            Some(
+                let analyzer = SourceAnalyzer::new(db, file_id, it.syntax(), None);
-                match_arm_list
+                Some(
-                    .arms()
+                    it
-                    .map(|match_arm| match_arm.pats())
+                        .arms()
-                    .flatten()
+                        .map(|match_arm| match_arm.pats())
-                    .map(|root_pat| get_pat_type_hints(db, &analyzer, root_pat, true))
+                        .flatten()
-                    .flatten()
+                        .map(|root_pat| get_pat_type_hints(db, &analyzer, root_pat, true))
-                    .collect(),
+                        .flatten()
-            )
+                        .collect(),
-        })
+                )
-        .accept(&node)?
+            },
+            _ => None,
+        }
+    }
 }
 fn get_pat_type_hints(
diff --git a/crates/ra_ide_api/src/join_lines.rs b/crates/ra_ide_api/src/join_lines.rs
index a71e4ed7d..6f71b27db 100644
--- a/crates/ra_ide_api/src/join_lines.rs
+++ b/crates/ra_ide_api/src/join_lines.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use itertools::Itertools;
 use ra_fmt::{compute_ws, extract_trivial_expression};
 use ra_syntax::{
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 44d1ec77b..24f1b91f6 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -49,6 +49,7 @@ mod test_utils;
 use std::sync::Arc;
+use ra_cfg::CfgOptions;
 use ra_db::{
    salsa::{self, ParallelDatabase},
    CheckCanceled, SourceDatabase,
@@ -322,7 +323,10 @@ impl Analysis {
        change.add_root(source_root, true);
        let mut crate_graph = CrateGraph::default();
        let file_id = FileId(0);
-        crate_graph.add_crate_root(file_id, Edition::Edition2018);
+        // FIXME: cfg options
+        // Default to enable test for single file.
+        let cfg_options = CfgOptions::default().atom("test".into());
+        crate_graph.add_crate_root(file_id, Edition::Edition2018, cfg_options);
        change.add_file(source_root, file_id, "main.rs".into(), Arc::new(text));
        change.set_crate_graph(crate_graph);
        host.apply_change(change);
diff --git a/crates/ra_ide_api/src/line_index.rs b/crates/ra_ide_api/src/line_index.rs
index 71de8a928..710890d27 100644
--- a/crates/ra_ide_api/src/line_index.rs
+++ b/crates/ra_ide_api/src/line_index.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::TextUnit;
 use rustc_hash::FxHashMap;
 use superslice::Ext;
@@ -278,5 +280,4 @@ const C: char = \"メ メ\";
        assert_eq!(col_index.utf16_to_utf8_col(2, 15), TextUnit::from_usize(15));
    }
 }
diff --git a/crates/ra_ide_api/src/line_index_utils.rs b/crates/ra_ide_api/src/line_index_utils.rs
index 534009b98..bd1e08feb 100644
--- a/crates/ra_ide_api/src/line_index_utils.rs
+++ b/crates/ra_ide_api/src/line_index_utils.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{line_index::Utf16Char, LineCol, LineIndex};
 use ra_syntax::{TextRange, TextUnit};
 use ra_text_edit::{AtomTextEdit, TextEdit};
diff --git a/crates/ra_ide_api/src/marks.rs b/crates/ra_ide_api/src/marks.rs
index c3752cc54..3f4ba248b 100644
--- a/crates/ra_ide_api/src/marks.rs
+++ b/crates/ra_ide_api/src/marks.rs
@@ -1,3 +1,5 @@
+//! See test_utils/src/marks.rs
 test_utils::marks!(
    inserts_parens_for_function_calls
    goto_definition_works_for_macros
diff --git a/crates/ra_ide_api/src/matching_brace.rs b/crates/ra_ide_api/src/matching_brace.rs
index e802d01e4..d1204fac0 100644
--- a/crates/ra_ide_api/src/matching_brace.rs
+++ b/crates/ra_ide_api/src/matching_brace.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_syntax::{ast::AstNode, SourceFile, SyntaxKind, TextUnit, T};
 pub fn matching_brace(file: &SourceFile, offset: TextUnit) -> Option<TextUnit> {
diff --git a/crates/ra_ide_api/src/mock_analysis.rs b/crates/ra_ide_api/src/mock_analysis.rs
index 132f6f875..80b71894c 100644
--- a/crates/ra_ide_api/src/mock_analysis.rs
+++ b/crates/ra_ide_api/src/mock_analysis.rs
@@ -1,5 +1,8 @@
+//! FIXME: write short doc here
 use std::sync::Arc;
+use ra_cfg::CfgOptions;
 use relative_path::RelativePathBuf;
 use test_utils::{extract_offset, extract_range, parse_fixture, CURSOR_MARKER};
@@ -91,10 +94,11 @@ impl MockAnalysis {
            assert!(path.starts_with('/'));
            let path = RelativePathBuf::from_path(&path[1..]).unwrap();
            let file_id = FileId(i as u32 + 1);
+            let cfg_options = CfgOptions::default();
            if path == "/lib.rs" || path == "/main.rs" {
-                root_crate = Some(crate_graph.add_crate_root(file_id, Edition2018));
+                root_crate = Some(crate_graph.add_crate_root(file_id, Edition2018, cfg_options));
            } else if path.ends_with("/lib.rs") {
-                let other_crate = crate_graph.add_crate_root(file_id, Edition2018);
+                let other_crate = crate_graph.add_crate_root(file_id, Edition2018, cfg_options);
                let crate_name = path.parent().unwrap().file_name().unwrap();
                if let Some(root_crate) = root_crate {
                    crate_graph.add_dep(root_crate, crate_name.into(), other_crate).unwrap();
diff --git a/crates/ra_ide_api/src/name_ref_kind.rs b/crates/ra_ide_api/src/name_ref_kind.rs
index aff03464a..149585971 100644
--- a/crates/ra_ide_api/src/name_ref_kind.rs
+++ b/crates/ra_ide_api/src/name_ref_kind.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::Either;
 use ra_syntax::{ast, AstNode, AstPtr};
 use test_utils::tested_by;
diff --git a/crates/ra_ide_api/src/parent_module.rs b/crates/ra_ide_api/src/parent_module.rs
index 3668da8d7..566509849 100644
--- a/crates/ra_ide_api/src/parent_module.rs
+++ b/crates/ra_ide_api/src/parent_module.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::{CrateId, FileId, FilePosition};
 use crate::{db::RootDatabase, NavigationTarget};
@@ -39,6 +41,7 @@ mod tests {
        AnalysisChange, CrateGraph,
        Edition::Edition2018,
    };
+    use ra_cfg::CfgOptions;
    #[test]
    fn test_resolve_parent_module() {
@@ -86,7 +89,7 @@ mod tests {
        assert!(host.analysis().crate_for(mod_file).unwrap().is_empty());
        let mut crate_graph = CrateGraph::default();
-        let crate_id = crate_graph.add_crate_root(root_file, Edition2018);
+        let crate_id = crate_graph.add_crate_root(root_file, Edition2018, CfgOptions::default());
        let mut change = AnalysisChange::new();
        change.set_crate_graph(crate_graph);
        host.apply_change(change);
diff --git a/crates/ra_ide_api/src/references.rs b/crates/ra_ide_api/src/references.rs
index acca71f2a..84c2eb793 100644
--- a/crates/ra_ide_api/src/references.rs
+++ b/crates/ra_ide_api/src/references.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use hir::{Either, ModuleSource};
 use ra_db::SourceDatabase;
 use ra_syntax::{algo::find_node_at_offset, ast, AstNode, SourceFile, SyntaxNode};
diff --git a/crates/ra_ide_api/src/runnables.rs b/crates/ra_ide_api/src/runnables.rs
index 095ca56c4..910883da7 100644
--- a/crates/ra_ide_api/src/runnables.rs
+++ b/crates/ra_ide_api/src/runnables.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use itertools::Itertools;
 use ra_db::SourceDatabase;
 use ra_syntax::{
@@ -229,5 +231,4 @@ mod tests {
        let runnables = analysis.runnables(pos.file_id).unwrap();
        assert!(runnables.is_empty())
    }
 }
diff --git a/crates/ra_ide_api/src/snapshots/highlighting.html b/crates/ra_ide_api/src/snapshots/highlighting.html
index b39c4d371..ae30ebba3 100644
--- a/crates/ra_ide_api/src/snapshots/highlighting.html
+++ b/crates/ra_ide_api/src/snapshots/highlighting.html
@@ -19,7 +19,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .keyword\.unsafe   { color: #DFAF8F; }
 .keyword\.control  { color: #F0DFAF; font-weight: bold; }
 </style>
-<pre><code><span class="attribute">#</span><span class="attribute">[</span><span class="attribute">derive</span><span class="attribute">(</span><span class="attribute">Clone</span><span class="attribute">,</span><span class="attribute"> </span><span class="attribute">Debug</span><span class="attribute">)</span><span class="attribute">]</span>
+<pre><code><span class="attribute">#</span><span class="attribute">[</span><span class="attribute text">derive</span><span class="attribute">(</span><span class="attribute">Clone</span><span class="attribute">,</span><span class="attribute"> </span><span class="attribute">Debug</span><span class="attribute">)</span><span class="attribute">]</span>
 <span class="keyword">struct</span> <span class="type">Foo</span> {
    <span class="keyword">pub</span> <span class="field">x</span>: <span class="type">i32</span>,
    <span class="keyword">pub</span> <span class="field">y</span>: <span class="type">i32</span>,
diff --git a/crates/ra_ide_api/src/status.rs b/crates/ra_ide_api/src/status.rs
index dee2ea46a..f91f16c8e 100644
--- a/crates/ra_ide_api/src/status.rs
+++ b/crates/ra_ide_api/src/status.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{fmt, iter::FromIterator, sync::Arc};
 use hir::MacroFile;
diff --git a/crates/ra_ide_api/src/symbol_index.rs b/crates/ra_ide_api/src/symbol_index.rs
index 02cdfbc60..797e9926f 100644
--- a/crates/ra_ide_api/src/symbol_index.rs
+++ b/crates/ra_ide_api/src/symbol_index.rs
@@ -32,9 +32,8 @@ use ra_db::{
    SourceDatabase, SourceRootId,
 };
 use ra_syntax::{
-    algo::visit::{visitor, Visitor},
    ast::{self, NameOwner},
-    AstNode, Parse, SmolStr, SourceFile,
+    match_ast, AstNode, Parse, SmolStr, SourceFile,
    SyntaxKind::{self, *},
    SyntaxNode, SyntaxNodePtr, TextRange, WalkEvent,
 };
@@ -306,16 +305,19 @@ fn to_symbol(node: &SyntaxNode) -> Option<(SmolStr, SyntaxNodePtr, TextRange)> {
        Some((name, ptr, name_range))
    }
-    visitor()
+    match_ast! {
-        .visit(decl::<ast::FnDef>)
+        match node {
-        .visit(decl::<ast::StructDef>)
+            ast::FnDef(it) => { decl(it) },
-        .visit(decl::<ast::EnumDef>)
+            ast::StructDef(it) => { decl(it) },
-        .visit(decl::<ast::TraitDef>)
+            ast::EnumDef(it) => { decl(it) },
-        .visit(decl::<ast::Module>)
+            ast::TraitDef(it) => { decl(it) },
-        .visit(decl::<ast::TypeAliasDef>)
+            ast::Module(it) => { decl(it) },
-        .visit(decl::<ast::ConstDef>)
+            ast::TypeAliasDef(it) => { decl(it) },
-        .visit(decl::<ast::StaticDef>)
+            ast::ConstDef(it) => { decl(it) },
-        .accept(node)?
+            ast::StaticDef(it) => { decl(it) },
+            _ => None,
+        }
+    }
 }
 fn to_file_symbol(node: &SyntaxNode, file_id: FileId) -> Option<FileSymbol> {
diff --git a/crates/ra_ide_api/src/syntax_highlighting.rs b/crates/ra_ide_api/src/syntax_highlighting.rs
index 3d7f91c1d..9ae2dc061 100644
--- a/crates/ra_ide_api/src/syntax_highlighting.rs
+++ b/crates/ra_ide_api/src/syntax_highlighting.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use rustc_hash::{FxHashMap, FxHashSet};
 use hir::{Mutability, Ty};
diff --git a/crates/ra_ide_api/src/syntax_tree.rs b/crates/ra_ide_api/src/syntax_tree.rs
index e2bb120b4..4d0f0fc47 100644
--- a/crates/ra_ide_api/src/syntax_tree.rs
+++ b/crates/ra_ide_api/src/syntax_tree.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::db::RootDatabase;
 use ra_db::SourceDatabase;
 use ra_syntax::{
diff --git a/crates/ra_ide_api/src/test_utils.rs b/crates/ra_ide_api/src/test_utils.rs
index 6e0d883b4..8adb214d4 100644
--- a/crates/ra_ide_api/src/test_utils.rs
+++ b/crates/ra_ide_api/src/test_utils.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_syntax::{SourceFile, TextUnit};
 use ra_text_edit::TextEdit;
diff --git a/crates/ra_ide_api/src/typing.rs b/crates/ra_ide_api/src/typing.rs
index 2d4491442..2f5782012 100644
--- a/crates/ra_ide_api/src/typing.rs
+++ b/crates/ra_ide_api/src/typing.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_db::{FilePosition, SourceDatabase};
 use ra_fmt::leading_indent;
 use ra_syntax::{
diff --git a/crates/ra_ide_api/src/wasm_shims.rs b/crates/ra_ide_api/src/wasm_shims.rs
index 592dddf44..088cc9be4 100644
--- a/crates/ra_ide_api/src/wasm_shims.rs
+++ b/crates/ra_ide_api/src/wasm_shims.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #[cfg(not(feature = "wasm"))]
 pub use std::time::Instant;
diff --git a/crates/ra_lsp_server/Cargo.toml b/crates/ra_lsp_server/Cargo.toml
index 677d81835..aedc55a95 100644
--- a/crates/ra_lsp_server/Cargo.toml
+++ b/crates/ra_lsp_server/Cargo.toml
@@ -19,6 +19,7 @@ jod-thread = "0.1.0"
 ra_vfs = "0.4.0"
 ra_syntax = { path = "../ra_syntax" }
 ra_db = { path = "../ra_db" }
+ra_cfg = { path = "../ra_cfg" }
 ra_text_edit = { path = "../ra_text_edit" }
 ra_ide_api = { path = "../ra_ide_api" }
 lsp-server = "0.2.0"
diff --git a/crates/ra_lsp_server/src/caps.rs b/crates/ra_lsp_server/src/caps.rs
index 22fc97a97..30bcbd7a8 100644
--- a/crates/ra_lsp_server/src/caps.rs
+++ b/crates/ra_lsp_server/src/caps.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use lsp_types::{
    CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
    DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability, GenericCapability,
diff --git a/crates/ra_lsp_server/src/cargo_target_spec.rs b/crates/ra_lsp_server/src/cargo_target_spec.rs
index a083bb311..d996b53de 100644
--- a/crates/ra_lsp_server/src/cargo_target_spec.rs
+++ b/crates/ra_lsp_server/src/cargo_target_spec.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_ide_api::{FileId, RunnableKind};
 use ra_project_model::{self, ProjectWorkspace, TargetKind};
diff --git a/crates/ra_lsp_server/src/config.rs b/crates/ra_lsp_server/src/config.rs
index cf53e7c4c..579d4c692 100644
--- a/crates/ra_lsp_server/src/config.rs
+++ b/crates/ra_lsp_server/src/config.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Deserializer};
diff --git a/crates/ra_lsp_server/src/conv.rs b/crates/ra_lsp_server/src/conv.rs
index d78f77925..1318a1738 100644
--- a/crates/ra_lsp_server/src/conv.rs
+++ b/crates/ra_lsp_server/src/conv.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use lsp_types::{
    self, CreateFile, DiagnosticSeverity, DocumentChangeOperation, DocumentChanges, Documentation,
    Location, LocationLink, MarkupContent, MarkupKind, Position, Range, RenameFile, ResourceOp,
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index fa3d88abd..7a71a90fb 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #![recursion_limit = "512"]
 mod caps;
 mod cargo_target_spec;
diff --git a/crates/ra_lsp_server/src/main.rs b/crates/ra_lsp_server/src/main.rs
index 852fae027..7d9a1d054 100644
--- a/crates/ra_lsp_server/src/main.rs
+++ b/crates/ra_lsp_server/src/main.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use flexi_logger::{Duplicate, Logger};
 use lsp_server::Connection;
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 2059f9800..35c35d32b 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod handlers;
 mod subscriptions;
 pub(crate) mod pending_requests;
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index ae57e57e9..10e271376 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{fmt::Write as _, io::Write as _};
 use lsp_server::ErrorCode;
diff --git a/crates/ra_lsp_server/src/main_loop/pending_requests.rs b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
index 7a99fc679..e7ea7aa5b 100644
--- a/crates/ra_lsp_server/src/main_loop/pending_requests.rs
+++ b/crates/ra_lsp_server/src/main_loop/pending_requests.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::time::{Duration, Instant};
 use lsp_server::RequestId;
diff --git a/crates/ra_lsp_server/src/main_loop/subscriptions.rs b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
index bbeda723c..3856263b0 100644
--- a/crates/ra_lsp_server/src/main_loop/subscriptions.rs
+++ b/crates/ra_lsp_server/src/main_loop/subscriptions.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_ide_api::FileId;
 use rustc_hash::FxHashSet;
diff --git a/crates/ra_lsp_server/src/markdown.rs b/crates/ra_lsp_server/src/markdown.rs
index c1eb0236a..f51fc4ade 100644
--- a/crates/ra_lsp_server/src/markdown.rs
+++ b/crates/ra_lsp_server/src/markdown.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 pub(crate) fn format_docs(src: &str) -> String {
    let mut processed_lines = Vec::new();
    let mut in_code_block = false;
@@ -70,5 +72,4 @@ let a = 1;
            "```rust\nfn main(){}\n```\nSome comment.\n```rust\nlet a = 1;\n```"
        );
    }
 }
diff --git a/crates/ra_lsp_server/src/req.rs b/crates/ra_lsp_server/src/req.rs
index 0540f166e..d25fc5726 100644
--- a/crates/ra_lsp_server/src/req.rs
+++ b/crates/ra_lsp_server/src/req.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use lsp_types::{Location, Position, Range, TextDocumentIdentifier, Url};
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 232409c3b..27da751ab 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    path::{Path, PathBuf},
    sync::Arc,
@@ -11,7 +13,7 @@ use ra_ide_api::{
    Analysis, AnalysisChange, AnalysisHost, CrateGraph, FeatureFlags, FileId, LibraryData,
    SourceRootId,
 };
-use ra_project_model::ProjectWorkspace;
+use ra_project_model::{get_rustc_cfg_options, ProjectWorkspace};
 use ra_vfs::{LineEndings, RootEntry, Vfs, VfsChange, VfsFile, VfsRoot, VfsTask, Watch};
 use ra_vfs_glob::{Glob, RustPackageFilterBuilder};
 use relative_path::RelativePathBuf;
@@ -95,6 +97,10 @@ impl WorldState {
            change.set_debug_root_path(SourceRootId(r.0), vfs_root_path.display().to_string());
        }
+        // FIXME: Read default cfgs from config
+        let default_cfg_options =
+            get_rustc_cfg_options().atom("test".into()).atom("debug_assertion".into());
        // Create crate graph from all the workspaces
        let mut crate_graph = CrateGraph::default();
        let mut load = |path: &std::path::Path| {
@@ -102,7 +108,7 @@ impl WorldState {
            vfs_file.map(|f| FileId(f.0))
        };
        for ws in workspaces.iter() {
-            let (graph, crate_names) = ws.to_crate_graph(&mut load);
+            let (graph, crate_names) = ws.to_crate_graph(&default_cfg_options, &mut load);
            let shift = crate_graph.extend(graph);
            for (crate_id, name) in crate_names {
                change.set_debug_crate_name(crate_id.shift(shift), name)
diff --git a/crates/ra_lsp_server/tests/heavy_tests/main.rs b/crates/ra_lsp_server/tests/heavy_tests/main.rs
index 152681062..2ba82ab05 100644
--- a/crates/ra_lsp_server/tests/heavy_tests/main.rs
+++ b/crates/ra_lsp_server/tests/heavy_tests/main.rs
@@ -286,7 +286,13 @@ fn test_missing_module_code_action_in_json_project() {
    let project = json!({
        "roots": [path],
-        "crates": [ { "root_module": path.join("src/lib.rs"), "deps": [], "edition": "2015" } ]
+        "crates": [ {
+            "root_module": path.join("src/lib.rs"),
+            "deps": [],
+            "edition": "2015",
+            "atom_cfgs": [],
+            "key_value_cfgs": {}
+        } ]
    });
    let code = format!(
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index a0904323c..afdbee84e 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -1,7 +1,7 @@
-/// `mbe` (short for Macro By Example) crate contains code for handling
+//! `mbe` (short for Macro By Example) crate contains code for handling
-/// `macro_rules` macros. It uses `TokenTree` (from `ra_tt` package) as the
+//! `macro_rules` macros. It uses `TokenTree` (from `ra_tt` package) as the
-/// interface, although it contains some code to bridge `SyntaxNode`s and
+//! interface, although it contains some code to bridge `SyntaxNode`s and
-/// `TokenTree`s as well!
+//! `TokenTree`s as well!
 mod parser;
 mod mbe_expander;
diff --git a/crates/ra_mbe/src/mbe_expander/matcher.rs b/crates/ra_mbe/src/mbe_expander/matcher.rs
index aff953102..0548e8512 100644
--- a/crates/ra_mbe/src/mbe_expander/matcher.rs
+++ b/crates/ra_mbe/src/mbe_expander/matcher.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{
    mbe_expander::{Binding, Bindings, Fragment},
    parser::{parse_pattern, Op, RepeatKind, Separator},
diff --git a/crates/ra_mbe/src/mbe_expander/transcriber.rs b/crates/ra_mbe/src/mbe_expander/transcriber.rs
index c22680b93..ed094d5bb 100644
--- a/crates/ra_mbe/src/mbe_expander/transcriber.rs
+++ b/crates/ra_mbe/src/mbe_expander/transcriber.rs
@@ -86,7 +86,7 @@ fn expand_subtree(ctx: &mut ExpandCtx, template: &tt::Subtree) -> Result<tt::Sub
 fn expand_var(ctx: &mut ExpandCtx, v: &SmolStr) -> Result<Fragment, ExpandError> {
    let res = if v == "crate" {
-        // FIXME: Properly handle $crate token
+        // We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path.
        let tt =
            tt::Leaf::from(tt::Ident { text: "$crate".into(), id: tt::TokenId::unspecified() })
                .into();
diff --git a/crates/ra_mbe/src/subtree_source.rs b/crates/ra_mbe/src/subtree_source.rs
index cf7458905..7ef45f6dc 100644
--- a/crates/ra_mbe/src/subtree_source.rs
+++ b/crates/ra_mbe/src/subtree_source.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_parser::{Token, TokenSource};
 use ra_syntax::{classify_literal, SmolStr, SyntaxKind, SyntaxKind::*, T};
 use std::cell::{Cell, Ref, RefCell};
diff --git a/crates/ra_mbe/src/syntax_bridge.rs b/crates/ra_mbe/src/syntax_bridge.rs
index 2d035307b..1b543c84b 100644
--- a/crates/ra_mbe/src/syntax_bridge.rs
+++ b/crates/ra_mbe/src/syntax_bridge.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_parser::{
    FragmentKind::{self, *},
    ParseError, TreeSink,
diff --git a/crates/ra_mbe/src/tt_iter.rs b/crates/ra_mbe/src/tt_iter.rs
index c53f99d1e..319f1ee65 100644
--- a/crates/ra_mbe/src/tt_iter.rs
+++ b/crates/ra_mbe/src/tt_iter.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #[derive(Debug, Clone)]
 pub(crate) struct TtIter<'a> {
    pub(crate) inner: std::slice::Iter<'a, tt::TokenTree>,
diff --git a/crates/ra_parser/src/grammar.rs b/crates/ra_parser/src/grammar.rs
index e2355aff9..6e9e212b7 100644
--- a/crates/ra_parser/src/grammar.rs
+++ b/crates/ra_parser/src/grammar.rs
@@ -135,7 +135,6 @@ pub(crate) mod fragments {
        m.complete(p, MACRO_STMTS);
    }
 }
 pub(crate) fn reparser(
diff --git a/crates/ra_parser/src/grammar/attributes.rs b/crates/ra_parser/src/grammar/attributes.rs
index 1cfd301b5..f3158ade3 100644
--- a/crates/ra_parser/src/grammar/attributes.rs
+++ b/crates/ra_parser/src/grammar/attributes.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn inner_attributes(p: &mut Parser) {
@@ -22,8 +24,23 @@ fn attribute(p: &mut Parser, inner: bool) {
        p.bump(T![!]);
    }
-    if p.at(T!['[']) {
+    if p.eat(T!['[']) {
-        items::token_tree(p);
+        paths::use_path(p);
+        match p.current() {
+            T![=] => {
+                p.bump(T![=]);
+                if expressions::literal(p).is_none() {
+                    p.error("expected literal");
+                }
+            }
+            T!['('] | T!['['] | T!['{'] => items::token_tree(p),
+            _ => {}
+        }
+        if !p.eat(T![']']) {
+            p.error("expected `]`");
+        }
    } else {
        p.error("expected `[`");
    }
diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index 80b085280..45f2e3de4 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod atom;
 pub(crate) use self::atom::match_arm_list;
@@ -248,6 +250,7 @@ fn current_op(p: &Parser) -> (u8, SyntaxKind) {
        T![!] if p.at(T![!=])  => (5,  T![!=]),
        T![-] if p.at(T![-=])  => (1,  T![-=]),
        T![-]                  => (10, T![-]),
+        T![as]                 => (12, T![as]),
        _                      => NOT_AN_OP
    }
@@ -276,6 +279,14 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> (Option<CompletedMarker>,
        if op_bp < bp {
            break;
        }
+        // test as_precedence
+        // fn foo() {
+        //     let _ = &1 as *const i32;
+        // }
+        if p.at(T![as]) {
+            lhs = cast_expr(p, lhs);
+            continue;
+        }
        let m = lhs.precede(p);
        p.bump(op);
@@ -333,9 +344,16 @@ fn lhs(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)>
            // }
            //
            let (lhs, blocklike) = atom::atom_expr(p, r)?;
-            return Some(postfix_expr(p, lhs, blocklike, !(r.prefer_stmt && blocklike.is_block())));
+            return Some(postfix_expr(
+                p,
+                lhs,
+                blocklike,
+                !(r.prefer_stmt && blocklike.is_block()),
+                r.forbid_structs,
+            ));
        }
    };
+    // parse the interior of the unary expression
    expr_bp(p, r, 255);
    Some((m.complete(p, kind), BlockLike::NotBlock))
 }
@@ -348,6 +366,7 @@ fn postfix_expr(
    // `while true {break}; ();`
    mut block_like: BlockLike,
    mut allow_calls: bool,
+    forbid_structs: bool,
 ) -> (CompletedMarker, BlockLike) {
    loop {
        lhs = match p.current() {
@@ -361,7 +380,7 @@ fn postfix_expr(
            // }
            T!['('] if allow_calls => call_expr(p, lhs),
            T!['['] if allow_calls => index_expr(p, lhs),
-            T![.] => match postfix_dot_expr(p, lhs) {
+            T![.] => match postfix_dot_expr(p, lhs, forbid_structs) {
                Ok(it) => it,
                Err(it) => {
                    lhs = it;
@@ -369,7 +388,6 @@ fn postfix_expr(
                }
            },
            T![?] => try_expr(p, lhs),
-            T![as] => cast_expr(p, lhs),
            _ => break,
        };
        allow_calls = true;
@@ -380,6 +398,7 @@ fn postfix_expr(
    fn postfix_dot_expr(
        p: &mut Parser,
        lhs: CompletedMarker,
+        forbid_structs: bool,
    ) -> Result<CompletedMarker, CompletedMarker> {
        assert!(p.at(T![.]));
        if p.nth(1) == IDENT && (p.nth(2) == T!['('] || p.nth_at(2, T![::])) {
@@ -400,10 +419,17 @@ fn postfix_expr(
        }
        // test postfix_range
-        // fn foo() { let x = 1..; }
+        // fn foo() {
-        for &(op, la) in [(T![..=], 3), (T![..], 2)].iter() {
+        //     let x = 1..;
+        //     match 1.. { _ => () };
+        //     match a.b()..S { _ => () };
+        // }
+        for &(op, la) in &[(T![..=], 3), (T![..], 2)] {
            if p.at(op) {
-                return if EXPR_FIRST.contains(p.nth(la)) {
+                let next_token = p.nth(la);
+                let has_trailing_expression =
+                    !(forbid_structs && next_token == T!['{']) && EXPR_FIRST.contains(next_token);
+                return if has_trailing_expression {
                    Err(lhs)
                } else {
                    let m = lhs.precede(p);
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index 457f42a26..7454005c4 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 // test expr_literals
@@ -119,11 +121,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
            //        break;
            //    }
            // }
-            if r.forbid_structs {
+            block_expr(p, None)
-                return None;
-            } else {
-                block_expr(p, None)
-            }
        }
        T![return] => return_expr(p),
        T![continue] => continue_expr(p),
@@ -259,6 +257,7 @@ fn lambda_expr(p: &mut Parser) -> CompletedMarker {
 //     if true {} else {};
 //     if true {} else if false {} else {};
 //     if S {};
+//     if { true } { } else { };
 // }
 fn if_expr(p: &mut Parser) -> CompletedMarker {
    assert!(p.at(T![if]));
@@ -307,6 +306,7 @@ fn loop_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
 // fn foo() {
 //     while true {};
 //     while let Some(x) = it.next() {};
+//     while { true } {};
 // }
 fn while_expr(p: &mut Parser, m: Option<Marker>) -> CompletedMarker {
    assert!(p.at(T![while]));
@@ -354,6 +354,8 @@ fn cond(p: &mut Parser) {
 // fn foo() {
 //     match () { };
 //     match S {};
+//     match { } { _ => () };
+//     match { S {} } {};
 // }
 fn match_expr(p: &mut Parser) -> CompletedMarker {
    assert!(p.at(T![match]));
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 4c67a5c2e..85f7eeb00 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod consts;
 mod nominal;
 mod traits;
diff --git a/crates/ra_parser/src/grammar/items/consts.rs b/crates/ra_parser/src/grammar/items/consts.rs
index 310260689..742a7e056 100644
--- a/crates/ra_parser/src/grammar/items/consts.rs
+++ b/crates/ra_parser/src/grammar/items/consts.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn static_def(p: &mut Parser, m: Marker) {
diff --git a/crates/ra_parser/src/grammar/items/nominal.rs b/crates/ra_parser/src/grammar/items/nominal.rs
index bede3b692..9d8fb8486 100644
--- a/crates/ra_parser/src/grammar/items/nominal.rs
+++ b/crates/ra_parser/src/grammar/items/nominal.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn struct_def(p: &mut Parser, m: Marker, kind: SyntaxKind) {
diff --git a/crates/ra_parser/src/grammar/items/traits.rs b/crates/ra_parser/src/grammar/items/traits.rs
index 3742fd197..2c560e824 100644
--- a/crates/ra_parser/src/grammar/items/traits.rs
+++ b/crates/ra_parser/src/grammar/items/traits.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 // test trait_item
diff --git a/crates/ra_parser/src/grammar/items/use_item.rs b/crates/ra_parser/src/grammar/items/use_item.rs
index 63ac37e9e..e3b991c8c 100644
--- a/crates/ra_parser/src/grammar/items/use_item.rs
+++ b/crates/ra_parser/src/grammar/items/use_item.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn use_item(p: &mut Parser, m: Marker) {
diff --git a/crates/ra_parser/src/grammar/params.rs b/crates/ra_parser/src/grammar/params.rs
index efc329243..c10b53316 100644
--- a/crates/ra_parser/src/grammar/params.rs
+++ b/crates/ra_parser/src/grammar/params.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 // test param_list
diff --git a/crates/ra_parser/src/grammar/paths.rs b/crates/ra_parser/src/grammar/paths.rs
index 24b65128e..ca8e075a1 100644
--- a/crates/ra_parser/src/grammar/paths.rs
+++ b/crates/ra_parser/src/grammar/paths.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) const PATH_FIRST: TokenSet =
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index aa9a6d18e..f5d12278c 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) const PATTERN_FIRST: TokenSet = expressions::LITERAL_FIRST
diff --git a/crates/ra_parser/src/grammar/type_args.rs b/crates/ra_parser/src/grammar/type_args.rs
index 8e97fe03c..7256c2697 100644
--- a/crates/ra_parser/src/grammar/type_args.rs
+++ b/crates/ra_parser/src/grammar/type_args.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn opt_type_arg_list(p: &mut Parser, colon_colon_required: bool) {
diff --git a/crates/ra_parser/src/grammar/type_params.rs b/crates/ra_parser/src/grammar/type_params.rs
index 7071c70ea..34406b5bd 100644
--- a/crates/ra_parser/src/grammar/type_params.rs
+++ b/crates/ra_parser/src/grammar/type_params.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) fn opt_type_param_list(p: &mut Parser) {
diff --git a/crates/ra_parser/src/grammar/types.rs b/crates/ra_parser/src/grammar/types.rs
index 4e3522d48..d4ca94fca 100644
--- a/crates/ra_parser/src/grammar/types.rs
+++ b/crates/ra_parser/src/grammar/types.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use super::*;
 pub(super) const TYPE_FIRST: TokenSet = paths::PATH_FIRST.union(token_set![
diff --git a/crates/ra_parser/src/parser.rs b/crates/ra_parser/src/parser.rs
index f8fba6860..dafd5247b 100644
--- a/crates/ra_parser/src/parser.rs
+++ b/crates/ra_parser/src/parser.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::cell::Cell;
 use drop_bomb::DropBomb;
diff --git a/crates/ra_parser/src/syntax_kind.rs b/crates/ra_parser/src/syntax_kind.rs
index 3efcfa403..8d6bd057b 100644
--- a/crates/ra_parser/src/syntax_kind.rs
+++ b/crates/ra_parser/src/syntax_kind.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #[macro_use]
 mod generated;
diff --git a/crates/ra_parser/src/syntax_kind/generated.rs b/crates/ra_parser/src/syntax_kind/generated.rs
index 8b43d93fe..96b5bce88 100644
--- a/crates/ra_parser/src/syntax_kind/generated.rs
+++ b/crates/ra_parser/src/syntax_kind/generated.rs
@@ -1,4 +1,4 @@
-// Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`
+//! Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`
 #![allow(bad_style, missing_docs, unreachable_pub)]
 #[doc = r" The kind of syntax node, e.g. `IDENT`, `USE_KW`, or `STRUCT_DEF`."]
diff --git a/crates/ra_parser/src/token_set.rs b/crates/ra_parser/src/token_set.rs
index 79121b35f..6dc061889 100644
--- a/crates/ra_parser/src/token_set.rs
+++ b/crates/ra_parser/src/token_set.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::SyntaxKind;
 /// A bit-set of `SyntaxKind`s
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index d32a289be..885a98750 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod memory_usage;
 #[cfg(feature = "cpu_profiler")]
 mod google_cpu_profiler;
diff --git a/crates/ra_prof/src/memory_usage.rs b/crates/ra_prof/src/memory_usage.rs
index 8e8cb7299..ad005ea14 100644
--- a/crates/ra_prof/src/memory_usage.rs
+++ b/crates/ra_prof/src/memory_usage.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 pub struct MemoryUsage {
diff --git a/crates/ra_project_model/Cargo.toml b/crates/ra_project_model/Cargo.toml
index ae6b91aa6..a65100031 100644
--- a/crates/ra_project_model/Cargo.toml
+++ b/crates/ra_project_model/Cargo.toml
@@ -12,6 +12,7 @@ cargo_metadata = "0.8.2"
 ra_arena = { path = "../ra_arena" }
 ra_db = { path = "../ra_db" }
+ra_cfg = { path = "../ra_cfg" }
 serde = { version = "1.0.89", features = ["derive"] }
 serde_json = "1.0.39"
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 712d8818f..28dadea9d 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::path::{Path, PathBuf};
 use cargo_metadata::{CargoOpt, MetadataCommand};
@@ -37,6 +39,7 @@ struct PackageData {
    is_member: bool,
    dependencies: Vec<PackageDependency>,
    edition: Edition,
+    features: Vec<String>,
 }
 #[derive(Debug, Clone)]
@@ -89,6 +92,9 @@ impl Package {
    pub fn edition(self, ws: &CargoWorkspace) -> Edition {
        ws.packages[self].edition
    }
+    pub fn features(self, ws: &CargoWorkspace) -> &[String] {
+        &ws.packages[self].features
+    }
    pub fn targets<'a>(self, ws: &'a CargoWorkspace) -> impl Iterator<Item = Target> + 'a {
        ws.packages[self].targets.iter().cloned()
    }
@@ -142,6 +148,7 @@ impl CargoWorkspace {
                is_member,
                edition: Edition::from_string(&meta_pkg.edition),
                dependencies: Vec::new(),
+                features: Vec::new(),
            });
            let pkg_data = &mut packages[pkg];
            pkg_by_id.insert(meta_pkg.id.clone(), pkg);
@@ -162,6 +169,7 @@ impl CargoWorkspace {
                let dep = PackageDependency { name: dep_node.name, pkg: pkg_by_id[&dep_node.pkg] };
                packages[source].dependencies.push(dep);
            }
+            packages[source].features.extend(node.features);
        }
        Ok(CargoWorkspace { packages, targets, workspace_root: meta.workspace_root })
diff --git a/crates/ra_project_model/src/json_project.rs b/crates/ra_project_model/src/json_project.rs
index 9a9eb9e1f..1bacb1d09 100644
--- a/crates/ra_project_model/src/json_project.rs
+++ b/crates/ra_project_model/src/json_project.rs
@@ -1,5 +1,8 @@
+//! FIXME: write short doc here
 use std::path::PathBuf;
+use rustc_hash::{FxHashMap, FxHashSet};
 use serde::Deserialize;
 /// A root points to the directory which contains Rust crates. rust-analyzer watches all files in
@@ -17,6 +20,8 @@ pub struct Crate {
    pub(crate) root_module: PathBuf,
    pub(crate) edition: Edition,
    pub(crate) deps: Vec<Dep>,
+    pub(crate) atom_cfgs: FxHashSet<String>,
+    pub(crate) key_value_cfgs: FxHashMap<String, String>,
 }
 #[derive(Clone, Copy, Debug, Deserialize)]
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 4fa32dc34..640a5ebd3 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod cargo_workspace;
 mod json_project;
 mod sysroot;
@@ -7,8 +9,10 @@ use std::{
    fs::File,
    io::BufReader,
    path::{Path, PathBuf},
+    process::Command,
 };
+use ra_cfg::CfgOptions;
 use ra_db::{CrateGraph, CrateId, Edition, FileId};
 use rustc_hash::FxHashMap;
 use serde_json::from_reader;
@@ -115,6 +119,7 @@ impl ProjectWorkspace {
    pub fn to_crate_graph(
        &self,
+        default_cfg_options: &CfgOptions,
        load: &mut dyn FnMut(&Path) -> Option<FileId>,
    ) -> (CrateGraph, FxHashMap<CrateId, String>) {
        let mut crate_graph = CrateGraph::default();
@@ -129,7 +134,17 @@ impl ProjectWorkspace {
                            json_project::Edition::Edition2015 => Edition::Edition2015,
                            json_project::Edition::Edition2018 => Edition::Edition2018,
                        };
-                        crates.insert(crate_id, crate_graph.add_crate_root(file_id, edition));
+                        let mut cfg_options = default_cfg_options.clone();
+                        for name in &krate.atom_cfgs {
+                            cfg_options = cfg_options.atom(name.into());
+                        }
+                        for (key, value) in &krate.key_value_cfgs {
+                            cfg_options = cfg_options.key_value(key.into(), value.into());
+                        }
+                        crates.insert(
+                            crate_id,
+                            crate_graph.add_crate_root(file_id, edition, cfg_options),
+                        );
                    }
                }
@@ -155,7 +170,10 @@ impl ProjectWorkspace {
                let mut sysroot_crates = FxHashMap::default();
                for krate in sysroot.crates() {
                    if let Some(file_id) = load(krate.root(&sysroot)) {
-                        let crate_id = crate_graph.add_crate_root(file_id, Edition::Edition2018);
+                        // Crates from sysroot have `cfg(test)` disabled
+                        let cfg_options = default_cfg_options.clone().remove_atom(&"test".into());
+                        let crate_id =
+                            crate_graph.add_crate_root(file_id, Edition::Edition2018, cfg_options);
                        sysroot_crates.insert(krate, crate_id);
                        names.insert(crate_id, krate.name(&sysroot).to_string());
                    }
@@ -184,7 +202,11 @@ impl ProjectWorkspace {
                        let root = tgt.root(&cargo);
                        if let Some(file_id) = load(root) {
                            let edition = pkg.edition(&cargo);
-                            let crate_id = crate_graph.add_crate_root(file_id, edition);
+                            let cfg_options = default_cfg_options
+                                .clone()
+                                .features(pkg.features(&cargo).iter().map(Into::into));
+                            let crate_id =
+                                crate_graph.add_crate_root(file_id, edition, cfg_options);
                            names.insert(crate_id, pkg.name(&cargo).to_string());
                            if tgt.kind(&cargo) == TargetKind::Lib {
                                lib_tgt = Some(crate_id);
@@ -284,3 +306,32 @@ fn find_cargo_toml(path: &Path) -> Result<PathBuf> {
    }
    Err(format!("can't find Cargo.toml at {}", path.display()))?
 }
+pub fn get_rustc_cfg_options() -> CfgOptions {
+    let mut cfg_options = CfgOptions::default();
+    match (|| -> Result<_> {
+        // `cfg(test)` and `cfg(debug_assertion)` are handled outside, so we suppress them here.
+        let output = Command::new("rustc").args(&["--print", "cfg", "-O"]).output()?;
+        if !output.status.success() {
+            Err("failed to get rustc cfgs")?;
+        }
+        Ok(String::from_utf8(output.stdout)?)
+    })() {
+        Ok(rustc_cfgs) => {
+            for line in rustc_cfgs.lines() {
+                match line.find('=') {
+                    None => cfg_options = cfg_options.atom(line.into()),
+                    Some(pos) => {
+                        let key = &line[..pos];
+                        let value = line[pos + 1..].trim_matches('"');
+                        cfg_options = cfg_options.key_value(key.into(), value.into());
+                    }
+                }
+            }
+        }
+        Err(e) => log::error!("failed to get rustc cfgs: {}", e),
+    }
+    cfg_options
+}
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 0c27d4f4b..35d6df5cb 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    env,
    path::{Path, PathBuf},
diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index 724c38e17..9bc85404a 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -12,6 +12,8 @@ itertools = "0.8.0"
 rowan = "0.6.1"
 rustc_lexer = "0.1.0"
 rustc-hash = "1.0.1"
+arrayvec = "0.4.10"
+once_cell = "1.2.0"
 # ideally, `serde` should be enabled by `ra_lsp_server`, but we enable it here
 # to reduce number of compilations
diff --git a/crates/ra_syntax/fuzz/fuzz_targets/parser.rs b/crates/ra_syntax/fuzz/fuzz_targets/parser.rs
index 76a8b08d0..7bc4ef30d 100644
--- a/crates/ra_syntax/fuzz/fuzz_targets/parser.rs
+++ b/crates/ra_syntax/fuzz/fuzz_targets/parser.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #![no_main]
 use libfuzzer_sys::fuzz_target;
 use ra_syntax::fuzz::check_parser;
diff --git a/crates/ra_syntax/fuzz/fuzz_targets/reparse.rs b/crates/ra_syntax/fuzz/fuzz_targets/reparse.rs
index 45524d4c1..16598f5f1 100644
--- a/crates/ra_syntax/fuzz/fuzz_targets/reparse.rs
+++ b/crates/ra_syntax/fuzz/fuzz_targets/reparse.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #![no_main]
 use libfuzzer_sys::fuzz_target;
 use ra_syntax::fuzz::CheckReparse;
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 46680a08f..7cfea70f9 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -1,8 +1,9 @@
-pub mod visit;
+//! FIXME: write short doc here
 use std::ops::RangeInclusive;
 use itertools::Itertools;
+use ra_text_edit::TextEditBuilder;
 use rustc_hash::FxHashMap;
 use crate::{
@@ -63,6 +64,18 @@ pub enum InsertPosition<T> {
    After(T),
 }
+pub struct TreeDiff {
+    replacements: FxHashMap<SyntaxElement, SyntaxElement>,
+}
+impl TreeDiff {
+    pub fn into_text_edit(&self, builder: &mut TextEditBuilder) {
+        for (from, to) in self.replacements.iter() {
+            builder.replace(from.text_range(), to.to_string())
+        }
+    }
+}
 /// Finds minimal the diff, which, applied to `from`, will result in `to`.
 ///
 /// Specifically, returns a map whose keys are descendants of `from` and values
@@ -70,12 +83,12 @@ pub enum InsertPosition<T> {
 ///
 /// A trivial solution is a singletom map `{ from: to }`, but this function
 /// tries to find a more fine-grained diff.
-pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> FxHashMap<SyntaxElement, SyntaxElement> {
+pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
    let mut buf = FxHashMap::default();
    // FIXME: this is both horrible inefficient and gives larger than
    // necessary diff. I bet there's a cool algorithm to diff trees properly.
    go(&mut buf, from.clone().into(), to.clone().into());
-    return buf;
+    return TreeDiff { replacements: buf };
    fn go(
        buf: &mut FxHashMap<SyntaxElement, SyntaxElement>,
diff --git a/crates/ra_syntax/src/algo/visit.rs b/crates/ra_syntax/src/algo/visit.rs
deleted file mode 100644
index 87bd15cc0..000000000
--- a/crates/ra_syntax/src/algo/visit.rs
+++ /dev/null
@@ -1,110 +0,0 @@
-use crate::{AstNode, SyntaxNode};
-use std::marker::PhantomData;
-pub fn visitor<'a, T>() -> impl Visitor<'a, Output = T> {
-    EmptyVisitor { ph: PhantomData }
-}
-pub fn visitor_ctx<'a, T, C>(ctx: C) -> impl VisitorCtx<'a, Output = T, Ctx = C> {
-    EmptyVisitorCtx { ph: PhantomData, ctx }
-}
-pub trait Visitor<'a>: Sized {
-    type Output;
-    fn accept(self, node: &'a SyntaxNode) -> Option<Self::Output>;
-    fn visit<N, F>(self, f: F) -> Vis<Self, N, F>
-    where
-        N: AstNode + 'a,
-        F: FnOnce(N) -> Self::Output,
-    {
-        Vis { inner: self, f, ph: PhantomData }
-    }
-}
-pub trait VisitorCtx<'a>: Sized {
-    type Output;
-    type Ctx;
-    fn accept(self, node: &'a SyntaxNode) -> Result<Self::Output, Self::Ctx>;
-    fn visit<N, F>(self, f: F) -> VisCtx<Self, N, F>
-    where
-        N: AstNode + 'a,
-        F: FnOnce(N, Self::Ctx) -> Self::Output,
-    {
-        VisCtx { inner: self, f, ph: PhantomData }
-    }
-}
-#[derive(Debug)]
-struct EmptyVisitor<T> {
-    ph: PhantomData<fn() -> T>,
-}
-impl<'a, T> Visitor<'a> for EmptyVisitor<T> {
-    type Output = T;
-    fn accept(self, _node: &'a SyntaxNode) -> Option<T> {
-        None
-    }
-}
-#[derive(Debug)]
-struct EmptyVisitorCtx<T, C> {
-    ctx: C,
-    ph: PhantomData<fn() -> T>,
-}
-impl<'a, T, C> VisitorCtx<'a> for EmptyVisitorCtx<T, C> {
-    type Output = T;
-    type Ctx = C;
-    fn accept(self, _node: &'a SyntaxNode) -> Result<T, C> {
-        Err(self.ctx)
-    }
-}
-#[derive(Debug)]
-pub struct Vis<V, N, F> {
-    inner: V,
-    f: F,
-    ph: PhantomData<fn(N)>,
-}
-impl<'a, V, N, F> Visitor<'a> for Vis<V, N, F>
-where
-    V: Visitor<'a>,
-    N: AstNode + 'a,
-    F: FnOnce(N) -> <V as Visitor<'a>>::Output,
-{
-    type Output = <V as Visitor<'a>>::Output;
-    fn accept(self, node: &'a SyntaxNode) -> Option<Self::Output> {
-        let Vis { inner, f, .. } = self;
-        inner.accept(node).or_else(|| N::cast(node.clone()).map(f))
-    }
-}
-#[derive(Debug)]
-pub struct VisCtx<V, N, F> {
-    inner: V,
-    f: F,
-    ph: PhantomData<fn(N)>,
-}
-impl<'a, V, N, F> VisitorCtx<'a> for VisCtx<V, N, F>
-where
-    V: VisitorCtx<'a>,
-    N: AstNode + 'a,
-    F: FnOnce(N, <V as VisitorCtx<'a>>::Ctx) -> <V as VisitorCtx<'a>>::Output,
-{
-    type Output = <V as VisitorCtx<'a>>::Output;
-    type Ctx = <V as VisitorCtx<'a>>::Ctx;
-    fn accept(self, node: &'a SyntaxNode) -> Result<Self::Output, Self::Ctx> {
-        let VisCtx { inner, f, .. } = self;
-        inner.accept(node).or_else(|ctx| match N::cast(node.clone()) {
-            None => Err(ctx),
-            Some(node) => Ok(f(node, ctx)),
-        })
-    }
-}
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index f464d6534..1b2ce921a 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -5,6 +5,7 @@ mod traits;
 mod tokens;
 mod extensions;
 mod expr_extensions;
+pub mod edit;
 pub mod make;
 use std::marker::PhantomData;
diff --git a/crates/ra_syntax/src/ast/edit.rs b/crates/ra_syntax/src/ast/edit.rs
new file mode 100644
index 000000000..03f3b5fbb
--- /dev/null
+++ b/crates/ra_syntax/src/ast/edit.rs
@@ -0,0 +1,271 @@
+//! This module contains functions for editing syntax trees. As the trees are
+//! immutable, all function here return a fresh copy of the tree, instead of
+//! doing an in-place modification.
+use std::{iter, ops::RangeInclusive};
+use arrayvec::ArrayVec;
+use rustc_hash::FxHashMap;
+use crate::{
+    algo,
+    ast::{
+        self,
+        make::{self, tokens},
+        AstNode, TypeBoundsOwner,
+    },
+    AstToken, Direction, InsertPosition, SmolStr, SyntaxElement,
+    SyntaxKind::{ATTR, COMMENT, WHITESPACE},
+    SyntaxNode, T,
+};
+impl ast::FnDef {
+    #[must_use]
+    pub fn with_body(&self, body: ast::Block) -> ast::FnDef {
+        let mut to_insert: ArrayVec<[SyntaxElement; 2]> = ArrayVec::new();
+        let old_body_or_semi: SyntaxElement = if let Some(old_body) = self.body() {
+            old_body.syntax().clone().into()
+        } else if let Some(semi) = self.semicolon_token() {
+            to_insert.push(make::tokens::single_space().into());
+            semi.into()
+        } else {
+            to_insert.push(make::tokens::single_space().into());
+            to_insert.push(body.syntax().clone().into());
+            return insert_children(self, InsertPosition::Last, to_insert.into_iter());
+        };
+        to_insert.push(body.syntax().clone().into());
+        let replace_range = RangeInclusive::new(old_body_or_semi.clone(), old_body_or_semi);
+        replace_children(self, replace_range, to_insert.into_iter())
+    }
+}
+impl ast::ItemList {
+    #[must_use]
+    pub fn append_items(&self, items: impl Iterator<Item = ast::ImplItem>) -> ast::ItemList {
+        let mut res = self.clone();
+        if !self.syntax().text().contains_char('\n') {
+            res = res.make_multiline();
+        }
+        items.for_each(|it| res = res.append_item(it));
+        res
+    }
+    #[must_use]
+    pub fn append_item(&self, item: ast::ImplItem) -> ast::ItemList {
+        let (indent, position) = match self.impl_items().last() {
+            Some(it) => (
+                leading_indent(it.syntax()).unwrap_or_default().to_string(),
+                InsertPosition::After(it.syntax().clone().into()),
+            ),
+            None => match self.l_curly() {
+                Some(it) => (
+                    "    ".to_string() + &leading_indent(self.syntax()).unwrap_or_default(),
+                    InsertPosition::After(it),
+                ),
+                None => return self.clone(),
+            },
+        };
+        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
+        let to_insert: ArrayVec<[SyntaxElement; 2]> =
+            [ws.ws().into(), item.syntax().clone().into()].into();
+        insert_children(self, position, to_insert.into_iter())
+    }
+    fn l_curly(&self) -> Option<SyntaxElement> {
+        self.syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
+    }
+    fn make_multiline(&self) -> ast::ItemList {
+        let l_curly = match self.syntax().children_with_tokens().find(|it| it.kind() == T!['{']) {
+            Some(it) => it,
+            None => return self.clone(),
+        };
+        let sibling = match l_curly.next_sibling_or_token() {
+            Some(it) => it,
+            None => return self.clone(),
+        };
+        let existing_ws = match sibling.as_token() {
+            None => None,
+            Some(tok) if tok.kind() != WHITESPACE => None,
+            Some(ws) => {
+                if ws.text().contains('\n') {
+                    return self.clone();
+                }
+                Some(ws.clone())
+            }
+        };
+        let indent = leading_indent(self.syntax()).unwrap_or("".into());
+        let ws = tokens::WsBuilder::new(&format!("\n{}", indent));
+        let to_insert = iter::once(ws.ws().into());
+        match existing_ws {
+            None => insert_children(self, InsertPosition::After(l_curly), to_insert),
+            Some(ws) => {
+                replace_children(self, RangeInclusive::new(ws.clone().into(), ws.into()), to_insert)
+            }
+        }
+    }
+}
+impl ast::RecordFieldList {
+    #[must_use]
+    pub fn append_field(&self, field: &ast::RecordField) -> ast::RecordFieldList {
+        self.insert_field(InsertPosition::Last, field)
+    }
+    #[must_use]
+    pub fn insert_field(
+        &self,
+        position: InsertPosition<&'_ ast::RecordField>,
+        field: &ast::RecordField,
+    ) -> ast::RecordFieldList {
+        let is_multiline = self.syntax().text().contains_char('\n');
+        let ws;
+        let space = if is_multiline {
+            ws = tokens::WsBuilder::new(&format!(
+                "\n{}    ",
+                leading_indent(self.syntax()).unwrap_or("".into())
+            ));
+            ws.ws()
+        } else {
+            tokens::single_space()
+        };
+        let mut to_insert: ArrayVec<[SyntaxElement; 4]> = ArrayVec::new();
+        to_insert.push(space.into());
+        to_insert.push(field.syntax().clone().into());
+        to_insert.push(tokens::comma().into());
+        macro_rules! after_l_curly {
+            () => {{
+                let anchor = match self.l_curly() {
+                    Some(it) => it,
+                    None => return self.clone(),
+                };
+                InsertPosition::After(anchor)
+            }};
+        }
+        macro_rules! after_field {
+            ($anchor:expr) => {
+                if let Some(comma) = $anchor
+                    .syntax()
+                    .siblings_with_tokens(Direction::Next)
+                    .find(|it| it.kind() == T![,])
+                {
+                    InsertPosition::After(comma)
+                } else {
+                    to_insert.insert(0, tokens::comma().into());
+                    InsertPosition::After($anchor.syntax().clone().into())
+                }
+            };
+        };
+        let position = match position {
+            InsertPosition::First => after_l_curly!(),
+            InsertPosition::Last => {
+                if !is_multiline {
+                    // don't insert comma before curly
+                    to_insert.pop();
+                }
+                match self.fields().last() {
+                    Some(it) => after_field!(it),
+                    None => after_l_curly!(),
+                }
+            }
+            InsertPosition::Before(anchor) => {
+                InsertPosition::Before(anchor.syntax().clone().into())
+            }
+            InsertPosition::After(anchor) => after_field!(anchor),
+        };
+        insert_children(self, position, to_insert.iter().cloned())
+    }
+    fn l_curly(&self) -> Option<SyntaxElement> {
+        self.syntax().children_with_tokens().find(|it| it.kind() == T!['{'])
+    }
+}
+impl ast::TypeParam {
+    #[must_use]
+    pub fn remove_bounds(&self) -> ast::TypeParam {
+        let colon = match self.colon_token() {
+            Some(it) => it,
+            None => return self.clone(),
+        };
+        let end = match self.type_bound_list() {
+            Some(it) => it.syntax().clone().into(),
+            None => colon.clone().into(),
+        };
+        replace_children(self, RangeInclusive::new(colon.into(), end), iter::empty())
+    }
+}
+#[must_use]
+pub fn strip_attrs_and_docs<N: ast::AttrsOwner>(node: &N) -> N {
+    N::cast(strip_attrs_and_docs_inner(node.syntax().clone())).unwrap()
+}
+fn strip_attrs_and_docs_inner(mut node: SyntaxNode) -> SyntaxNode {
+    while let Some(start) =
+        node.children_with_tokens().find(|it| it.kind() == ATTR || it.kind() == COMMENT)
+    {
+        let end = match &start.next_sibling_or_token() {
+            Some(el) if el.kind() == WHITESPACE => el.clone(),
+            Some(_) | None => start.clone(),
+        };
+        node = algo::replace_children(&node, RangeInclusive::new(start, end), &mut iter::empty());
+    }
+    node
+}
+#[must_use]
+pub fn replace_descendants<N: AstNode, D: AstNode>(
+    parent: &N,
+    replacement_map: impl Iterator<Item = (D, D)>,
+) -> N {
+    let map = replacement_map
+        .map(|(from, to)| (from.syntax().clone().into(), to.syntax().clone().into()))
+        .collect::<FxHashMap<_, _>>();
+    let new_syntax = algo::replace_descendants(parent.syntax(), &map);
+    N::cast(new_syntax).unwrap()
+}
+// Note this is copy-pasted from fmt. It seems like fmt should be a separate
+// crate, but basic tree building should be this crate. However, tree building
+// might want to call into fmt...
+fn leading_indent(node: &SyntaxNode) -> Option<SmolStr> {
+    let prev_tokens = std::iter::successors(node.first_token(), |token| token.prev_token());
+    for token in prev_tokens {
+        if let Some(ws) = ast::Whitespace::cast(token.clone()) {
+            let ws_text = ws.text();
+            if let Some(pos) = ws_text.rfind('\n') {
+                return Some(ws_text[pos + 1..].into());
+            }
+        }
+        if token.text().contains('\n') {
+            break;
+        }
+    }
+    None
+}
+#[must_use]
+fn insert_children<N: AstNode>(
+    parent: &N,
+    position: InsertPosition<SyntaxElement>,
+    mut to_insert: impl Iterator<Item = SyntaxElement>,
+) -> N {
+    let new_syntax = algo::insert_children(parent.syntax(), position, &mut to_insert);
+    N::cast(new_syntax).unwrap()
+}
+#[must_use]
+fn replace_children<N: AstNode>(
+    parent: &N,
+    to_replace: RangeInclusive<SyntaxElement>,
+    mut to_insert: impl Iterator<Item = SyntaxElement>,
+) -> N {
+    let new_syntax = algo::replace_children(parent.syntax(), to_replace, &mut to_insert);
+    N::cast(new_syntax).unwrap()
+}
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index 5f7e9f5b1..cefc00402 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -1,10 +1,8 @@
 //! Various extension methods to ast Nodes, which are hard to code-generate.
 //! Extensions for various expressions live in a sibling `expr_extensions` module.
-use itertools::Itertools;
 use crate::{
-    ast::{self, child_opt, children, AstNode, SyntaxNode},
+    ast::{self, child_opt, children, AstChildren, AstNode, AttrInput, SyntaxNode},
    SmolStr, SyntaxElement,
    SyntaxKind::*,
    SyntaxToken, T,
@@ -21,6 +19,16 @@ impl ast::NameRef {
    pub fn text(&self) -> &SmolStr {
        text_of_first_token(self.syntax())
    }
+    pub fn as_tuple_field(&self) -> Option<usize> {
+        self.syntax().children_with_tokens().find_map(|c| {
+            if c.kind() == SyntaxKind::INT_NUMBER {
+                c.as_token().and_then(|tok| tok.text().as_str().parse().ok())
+            } else {
+                None
+            }
+        })
+    }
 }
 fn text_of_first_token(node: &SyntaxNode) -> &SmolStr {
@@ -28,62 +36,37 @@ fn text_of_first_token(node: &SyntaxNode) -> &SmolStr {
 }
 impl ast::Attr {
-    pub fn is_inner(&self) -> bool {
+    pub fn as_simple_atom(&self) -> Option<SmolStr> {
-        let tt = match self.value() {
+        match self.input() {
-            None => return false,
+            None => self.simple_name(),
-            Some(tt) => tt,
+            Some(_) => None,
-        };
-        let prev = match tt.syntax().prev_sibling() {
-            None => return false,
-            Some(prev) => prev,
-        };
-        prev.kind() == T![!]
-    }
-    pub fn as_atom(&self) -> Option<SmolStr> {
-        let tt = self.value()?;
-        let (_bra, attr, _ket) = tt.syntax().children_with_tokens().collect_tuple()?;
-        if attr.kind() == IDENT {
-            Some(attr.as_token()?.text().clone())
-        } else {
-            None
        }
    }
-    pub fn as_call(&self) -> Option<(SmolStr, ast::TokenTree)> {
+    pub fn as_simple_call(&self) -> Option<(SmolStr, ast::TokenTree)> {
-        let tt = self.value()?;
+        match self.input() {
-        let (_bra, attr, args, _ket) = tt.syntax().children_with_tokens().collect_tuple()?;
+            Some(AttrInput::TokenTree(tt)) => Some((self.simple_name()?, tt)),
-        let args = ast::TokenTree::cast(args.as_node()?.clone())?;
+            _ => None,
-        if attr.kind() == IDENT {
-            Some((attr.as_token()?.text().clone(), args))
-        } else {
-            None
        }
    }
-    pub fn as_named(&self) -> Option<SmolStr> {
+    pub fn as_simple_key_value(&self) -> Option<(SmolStr, SmolStr)> {
-        let tt = self.value()?;
+        match self.input() {
-        let attr = tt.syntax().children_with_tokens().nth(1)?;
+            Some(AttrInput::Literal(lit)) => {
-        if attr.kind() == IDENT {
+                let key = self.simple_name()?;
-            Some(attr.as_token()?.text().clone())
+                // FIXME: escape? raw string?
-        } else {
+                let value = lit.syntax().first_token()?.text().trim_matches('"').into();
-            None
+                Some((key, value))
+            }
+            _ => None,
        }
    }
-    pub fn as_key_value(&self) -> Option<(SmolStr, SmolStr)> {
+    pub fn simple_name(&self) -> Option<SmolStr> {
-        let tt = self.value()?;
+        let path = self.path()?;
-        let tt_node = tt.syntax();
+        match (path.segment(), path.qualifier()) {
-        let attr = tt_node.children_with_tokens().nth(1)?;
+            (Some(segment), None) => Some(segment.syntax().first_token()?.text().clone()),
-        if attr.kind() == IDENT {
+            _ => None,
-            let key = attr.as_token()?.text().clone();
-            let val_node = tt_node.children_with_tokens().find(|t| t.kind() == STRING)?;
-            let val = val_node.as_token()?.text().trim_start_matches('"').trim_end_matches('"');
-            Some((key, SmolStr::new(val)))
-        } else {
-            None
        }
    }
 }
@@ -193,6 +176,16 @@ impl ast::ImplBlock {
    }
 }
+impl ast::AttrsOwner for ast::ImplItem {
+    fn attrs(&self) -> AstChildren<ast::Attr> {
+        match self {
+            ast::ImplItem::FnDef(it) => it.attrs(),
+            ast::ImplItem::TypeAliasDef(it) => it.attrs(),
+            ast::ImplItem::ConstDef(it) => it.attrs(),
+        }
+    }
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum StructKind {
    Tuple(ast::TupleFieldDefList),
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index dc1f8c82c..34b22c3e2 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1,4 +1,4 @@
-// Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`
+//! Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`
 use crate::{
    ast::{self, AstChildren, AstNode},
@@ -166,11 +166,52 @@ impl AstNode for Attr {
    }
 }
 impl Attr {
-    pub fn value(&self) -> Option<TokenTree> {
+    pub fn path(&self) -> Option<Path> {
+        AstChildren::new(&self.syntax).next()
+    }
+    pub fn input(&self) -> Option<AttrInput> {
        AstChildren::new(&self.syntax).next()
    }
 }
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum AttrInput {
+    Literal(Literal),
+    TokenTree(TokenTree),
+}
+impl From<Literal> for AttrInput {
+    fn from(node: Literal) -> AttrInput {
+        AttrInput::Literal(node)
+    }
+}
+impl From<TokenTree> for AttrInput {
+    fn from(node: TokenTree) -> AttrInput {
+        AttrInput::TokenTree(node)
+    }
+}
+impl AstNode for AttrInput {
+    fn can_cast(kind: SyntaxKind) -> bool {
+        match kind {
+            LITERAL | TOKEN_TREE => true,
+            _ => false,
+        }
+    }
+    fn cast(syntax: SyntaxNode) -> Option<Self> {
+        let res = match syntax.kind() {
+            LITERAL => AttrInput::Literal(Literal { syntax }),
+            TOKEN_TREE => AttrInput::TokenTree(TokenTree { syntax }),
+            _ => return None,
+        };
+        Some(res)
+    }
+    fn syntax(&self) -> &SyntaxNode {
+        match self {
+            AttrInput::Literal(it) => &it.syntax,
+            AttrInput::TokenTree(it) => &it.syntax,
+        }
+    }
+}
+impl AttrInput {}
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct AwaitExpr {
    pub(crate) syntax: SyntaxNode,
 }
@@ -1921,6 +1962,7 @@ impl AstNode for ModuleItem {
        }
    }
 }
+impl ast::AttrsOwner for ModuleItem {}
 impl ModuleItem {}
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Name {
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index c06c62b3b..287a40bee 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -133,3 +133,51 @@ fn ast_from_text<N: AstNode>(text: &str) -> N {
    let res = parse.tree().syntax().descendants().find_map(N::cast).unwrap();
    res
 }
+pub mod tokens {
+    use crate::{AstNode, Parse, SourceFile, SyntaxKind::*, SyntaxToken, T};
+    use once_cell::sync::Lazy;
+    static SOURCE_FILE: Lazy<Parse<SourceFile>> = Lazy::new(|| SourceFile::parse(",\n; ;"));
+    pub fn comma() -> SyntaxToken {
+        SOURCE_FILE
+            .tree()
+            .syntax()
+            .descendants_with_tokens()
+            .filter_map(|it| it.into_token())
+            .find(|it| it.kind() == T![,])
+            .unwrap()
+    }
+    pub fn single_space() -> SyntaxToken {
+        SOURCE_FILE
+            .tree()
+            .syntax()
+            .descendants_with_tokens()
+            .filter_map(|it| it.into_token())
+            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == " ")
+            .unwrap()
+    }
+    pub fn single_newline() -> SyntaxToken {
+        SOURCE_FILE
+            .tree()
+            .syntax()
+            .descendants_with_tokens()
+            .filter_map(|it| it.into_token())
+            .find(|it| it.kind() == WHITESPACE && it.text().as_str() == "\n")
+            .unwrap()
+    }
+    pub struct WsBuilder(SourceFile);
+    impl WsBuilder {
+        pub fn new(text: &str) -> WsBuilder {
+            WsBuilder(SourceFile::parse(text).ok().unwrap())
+        }
+        pub fn ws(&self) -> SyntaxToken {
+            self.0.syntax().first_child_or_token().unwrap().into_token().unwrap()
+        }
+    }
+}
diff --git a/crates/ra_syntax/src/ast/traits.rs b/crates/ra_syntax/src/ast/traits.rs
index c3e676d4c..f275a4955 100644
--- a/crates/ra_syntax/src/ast/traits.rs
+++ b/crates/ra_syntax/src/ast/traits.rs
@@ -99,7 +99,7 @@ pub trait AttrsOwner: AstNode {
        children(self)
    }
    fn has_atom_attr(&self, atom: &str) -> bool {
-        self.attrs().filter_map(|x| x.as_atom()).any(|x| x == atom)
+        self.attrs().filter_map(|x| x.as_simple_atom()).any(|x| x == atom)
    }
 }
diff --git a/crates/ra_syntax/src/fuzz.rs b/crates/ra_syntax/src/fuzz.rs
index 698a624ec..7012df7f0 100644
--- a/crates/ra_syntax/src/fuzz.rs
+++ b/crates/ra_syntax/src/fuzz.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{validation, AstNode, SourceFile, TextRange, TextUnit};
 use ra_text_edit::AtomTextEdit;
 use std::str::{self, FromStr};
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 5f395501a..25e6f64ce 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -1,5 +1,5 @@
 // Stores definitions which must be used in multiple places
-// See `cargo gen-syntax` (defined in crates/tools/src/main.rs)
+// See `cargo gen-syntax` (defined in crates/ra_tools/src/main.rs)
 Grammar(
    punct: [
        (";", "SEMI"),
@@ -397,7 +397,8 @@ Grammar(
        ),
        "ModuleItem": (
            enum: ["StructDef", "EnumDef", "FnDef", "TraitDef", "TypeAliasDef", "ImplBlock",
-                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ]
+                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ],
+            traits: ["AttrsOwner"]
        ),
        "ImplItem": (
            enum: ["FnDef", "TypeAliasDef", "ConstDef"]
@@ -576,7 +577,8 @@ Grammar(
            traits: [ "NameOwner", "AttrsOwner","DocCommentsOwner" ],
            options: [ "TokenTree", "Path" ],
        ),
-        "Attr": ( options: [ ["value", "TokenTree"] ] ),
+        "AttrInput": ( enum: [ "Literal", "TokenTree" ] ),
+        "Attr": ( options: [ "Path", [ "input", "AttrInput" ] ] ),
        "TokenTree": (),
        "TypeParamList": (
            collections: [
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index edb6076bb..c315ba552 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -160,6 +160,17 @@ impl SourceFile {
    }
 }
+#[macro_export]
+macro_rules! match_ast {
+    (match $node:ident {
+        $( ast::$ast:ident($it:ident) => $res:block, )*
+        _ => $catch_all:expr,
+    }) => {{
+        $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
+        { $catch_all }
+    }};
+}
 /// This test does not assert anything and instead just shows off the crate's
 /// API.
 #[test]
@@ -294,7 +305,7 @@ fn api_walkthrough() {
    // To recursively process the tree, there are three approaches:
    // 1. explicitly call getter methods on AST nodes.
    // 2. use descendants and `AstNode::cast`.
-    // 3. use descendants and the visitor.
+    // 3. use descendants and `match_ast!`.
    //
    // Here's how the first one looks like:
    let exprs_cast: Vec<String> = file
@@ -304,17 +315,17 @@ fn api_walkthrough() {
        .map(|expr| expr.syntax().text().to_string())
        .collect();
-    // An alternative is to use a visitor. The visitor does not do traversal
+    // An alternative is to use a macro.
-    // automatically (so it's more akin to a generic lambda) and is constructed
-    // from closures. This seems more flexible than a single generated visitor
-    // trait.
-    use algo::visit::{visitor, Visitor};
    let mut exprs_visit = Vec::new();
    for node in file.syntax().descendants() {
-        if let Some(result) =
+        match_ast! {
-            visitor().visit::<ast::Expr, _>(|expr| expr.syntax().text().to_string()).accept(&node)
+            match node {
-        {
+                ast::Expr(it) => {
-            exprs_visit.push(result);
+                    let res = it.syntax().text().to_string();
+                    exprs_visit.push(res);
+                },
+                _ => (),
+            }
        }
    }
    assert_eq!(exprs_cast, exprs_visit);
diff --git a/crates/ra_syntax/src/parsing/lexer.rs b/crates/ra_syntax/src/parsing/lexer.rs
index bdb01d40b..6d839208d 100644
--- a/crates/ra_syntax/src/parsing/lexer.rs
+++ b/crates/ra_syntax/src/parsing/lexer.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{
    SyntaxKind::{self, *},
    TextUnit,
diff --git a/crates/ra_syntax/src/parsing/text_token_source.rs b/crates/ra_syntax/src/parsing/text_token_source.rs
index 64cb20ae8..e793f93a4 100644
--- a/crates/ra_syntax/src/parsing/text_token_source.rs
+++ b/crates/ra_syntax/src/parsing/text_token_source.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use ra_parser::Token as PToken;
 use ra_parser::TokenSource;
diff --git a/crates/ra_syntax/src/parsing/text_tree_sink.rs b/crates/ra_syntax/src/parsing/text_tree_sink.rs
index be6e51780..142164316 100644
--- a/crates/ra_syntax/src/parsing/text_tree_sink.rs
+++ b/crates/ra_syntax/src/parsing/text_tree_sink.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::mem;
 use ra_parser::{ParseError, TreeSink};
diff --git a/crates/ra_syntax/src/ptr.rs b/crates/ra_syntax/src/ptr.rs
index 992034ef0..31167cada 100644
--- a/crates/ra_syntax/src/ptr.rs
+++ b/crates/ra_syntax/src/ptr.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{iter::successors, marker::PhantomData};
 use crate::{AstNode, SyntaxKind, SyntaxNode, TextRange};
diff --git a/crates/ra_syntax/src/syntax_error.rs b/crates/ra_syntax/src/syntax_error.rs
index 5aefec768..d6eca2ad7 100644
--- a/crates/ra_syntax/src/syntax_error.rs
+++ b/crates/ra_syntax/src/syntax_error.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::fmt;
 use ra_parser::ParseError;
diff --git a/crates/ra_syntax/src/validation.rs b/crates/ra_syntax/src/validation.rs
index 16824f3c4..ab4f15908 100644
--- a/crates/ra_syntax/src/validation.rs
+++ b/crates/ra_syntax/src/validation.rs
@@ -1,10 +1,11 @@
+//! FIXME: write short doc here
 mod block;
 use rustc_lexer::unescape;
 use crate::{
-    algo::visit::{visitor_ctx, VisitorCtx},
+    ast, match_ast, AstNode, SyntaxError, SyntaxErrorKind,
-    ast, AstNode, SyntaxError, SyntaxErrorKind,
    SyntaxKind::{BYTE, BYTE_STRING, CHAR, INT_NUMBER, STRING},
    SyntaxNode, SyntaxToken, TextUnit, T,
 };
@@ -95,12 +96,15 @@ impl From<rustc_lexer::unescape::EscapeError> for SyntaxErrorKind {
 pub(crate) fn validate(root: &SyntaxNode) -> Vec<SyntaxError> {
    let mut errors = Vec::new();
    for node in root.descendants() {
-        let _ = visitor_ctx(&mut errors)
+        match_ast! {
-            .visit::<ast::Literal, _>(validate_literal)
+            match node {
-            .visit::<ast::BlockExpr, _>(block::validate_block_expr)
+                ast::Literal(it) => { validate_literal(it, &mut errors) },
-            .visit::<ast::FieldExpr, _>(|it, errors| validate_numeric_name(it.name_ref(), errors))
+                ast::BlockExpr(it) => { block::validate_block_expr(it, &mut errors) },
-            .visit::<ast::RecordField, _>(|it, errors| validate_numeric_name(it.name_ref(), errors))
+                ast::FieldExpr(it) => { validate_numeric_name(it.name_ref(), &mut errors) },
-            .accept(&node);
+                ast::RecordField(it) => { validate_numeric_name(it.name_ref(), &mut errors) },
+                _ => (),
+            }
+        }
    }
    errors
 }
diff --git a/crates/ra_syntax/src/validation/block.rs b/crates/ra_syntax/src/validation/block.rs
index 3c9e96eb3..c85bbc1f4 100644
--- a/crates/ra_syntax/src/validation/block.rs
+++ b/crates/ra_syntax/src/validation/block.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{
    ast::{self, AstNode, AttrsOwner},
    SyntaxError,
diff --git a/crates/ra_syntax/test_data/parser/err/0005_attribute_recover.txt b/crates/ra_syntax/test_data/parser/err/0005_attribute_recover.txt
index 378b92834..7c1a23170 100644
--- a/crates/ra_syntax/test_data/parser/err/0005_attribute_recover.txt
+++ b/crates/ra_syntax/test_data/parser/err/0005_attribute_recover.txt
@@ -2,20 +2,22 @@ SOURCE_FILE@[0; 54)
  FN_DEF@[0; 31)
    ATTR@[0; 18)
      POUND@[0; 1) "#"
-      TOKEN_TREE@[1; 18)
+      L_BRACK@[1; 2) "["
-        L_BRACK@[1; 2) "["
+      PATH@[2; 5)
-        IDENT@[2; 5) "foo"
+        PATH_SEGMENT@[2; 5)
-        TOKEN_TREE@[5; 17)
+          NAME_REF@[2; 5)
-          L_PAREN@[5; 6) "("
+            IDENT@[2; 5) "foo"
-          IDENT@[6; 9) "foo"
+      TOKEN_TREE@[5; 17)
-          COMMA@[9; 10) ","
+        L_PAREN@[5; 6) "("
-          WHITESPACE@[10; 11) " "
+        IDENT@[6; 9) "foo"
-          PLUS@[11; 12) "+"
+        COMMA@[9; 10) ","
-          COMMA@[12; 13) ","
+        WHITESPACE@[10; 11) " "
-          WHITESPACE@[13; 14) " "
+        PLUS@[11; 12) "+"
-          INT_NUMBER@[14; 16) "92"
+        COMMA@[12; 13) ","
-          R_PAREN@[16; 17) ")"
+        WHITESPACE@[13; 14) " "
-        R_BRACK@[17; 18) "]"
+        INT_NUMBER@[14; 16) "92"
+        R_PAREN@[16; 17) ")"
+      R_BRACK@[17; 18) "]"
    WHITESPACE@[18; 19) "\n"
    FN_KW@[19; 21) "fn"
    WHITESPACE@[21; 22) " "
@@ -33,24 +35,26 @@ SOURCE_FILE@[0; 54)
  WHITESPACE@[31; 34) "\n\n\n"
  ATTR@[34; 53)
    POUND@[34; 35) "#"
-    TOKEN_TREE@[35; 53)
+    L_BRACK@[35; 36) "["
-      L_BRACK@[35; 36) "["
+    PATH@[36; 39)
-      IDENT@[36; 39) "foo"
+      PATH_SEGMENT@[36; 39)
-      TOKEN_TREE@[39; 53)
+        NAME_REF@[36; 39)
-        L_PAREN@[39; 40) "("
+          IDENT@[36; 39) "foo"
-        WHITESPACE@[40; 41) "\n"
+    TOKEN_TREE@[39; 53)
-        FN_KW@[41; 43) "fn"
+      L_PAREN@[39; 40) "("
-        WHITESPACE@[43; 44) " "
+      WHITESPACE@[40; 41) "\n"
-        IDENT@[44; 47) "foo"
+      FN_KW@[41; 43) "fn"
-        TOKEN_TREE@[47; 49)
+      WHITESPACE@[43; 44) " "
-          L_PAREN@[47; 48) "("
+      IDENT@[44; 47) "foo"
-          R_PAREN@[48; 49) ")"
+      TOKEN_TREE@[47; 49)
-        WHITESPACE@[49; 50) " "
+        L_PAREN@[47; 48) "("
-        TOKEN_TREE@[50; 53)
+        R_PAREN@[48; 49) ")"
-          L_CURLY@[50; 51) "{"
+      WHITESPACE@[49; 50) " "
-          WHITESPACE@[51; 52) "\n"
+      TOKEN_TREE@[50; 53)
-          R_CURLY@[52; 53) "}"
+        L_CURLY@[50; 51) "{"
+        WHITESPACE@[51; 52) "\n"
+        R_CURLY@[52; 53) "}"
  WHITESPACE@[53; 54) "\n"
 error 53: expected R_PAREN
-error 53: expected R_BRACK
+error 53: expected `]`
 error 53: expected an item
diff --git a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt b/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt
index 73d322c48..c5be73a5a 100644
--- a/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt
+++ b/crates/ra_syntax/test_data/parser/err/0028_macro_2.0.txt
@@ -60,10 +60,12 @@ SOURCE_FILE@[0; 349)
  FN_DEF@[95; 348)
    ATTR@[95; 102)
      POUND@[95; 96) "#"
-      TOKEN_TREE@[96; 102)
+      L_BRACK@[96; 97) "["
-        L_BRACK@[96; 97) "["
+      PATH@[97; 101)
-        IDENT@[97; 101) "test"
+        PATH_SEGMENT@[97; 101)
-        R_BRACK@[101; 102) "]"
+          NAME_REF@[97; 101)
+            IDENT@[97; 101) "test"
+      R_BRACK@[101; 102) "]"
    WHITESPACE@[102; 103) "\n"
    FN_KW@[103; 105) "fn"
    WHITESPACE@[105; 106) " "
diff --git a/crates/ra_syntax/test_data/parser/err/0031_block_inner_attrs.txt b/crates/ra_syntax/test_data/parser/err/0031_block_inner_attrs.txt
index f67325b76..522a0d0e0 100644
--- a/crates/ra_syntax/test_data/parser/err/0031_block_inner_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/err/0031_block_inner_attrs.txt
@@ -28,14 +28,16 @@ SOURCE_FILE@[0; 350)
              ATTR@[39; 83)
                POUND@[39; 40) "#"
                EXCL@[40; 41) "!"
-                TOKEN_TREE@[41; 83)
+                L_BRACK@[41; 42) "["
-                  L_BRACK@[41; 42) "["
+                PATH@[42; 45)
-                  IDENT@[42; 45) "doc"
+                  PATH_SEGMENT@[42; 45)
-                  TOKEN_TREE@[45; 82)
+                    NAME_REF@[42; 45)
-                    L_PAREN@[45; 46) "("
+                      IDENT@[42; 45) "doc"
-                    STRING@[46; 81) "\"Inner attributes not ..."
+                TOKEN_TREE@[45; 82)
-                    R_PAREN@[81; 82) ")"
+                  L_PAREN@[45; 46) "("
-                  R_BRACK@[82; 83) "]"
+                  STRING@[46; 81) "\"Inner attributes not ..."
+                  R_PAREN@[81; 82) ")"
+                R_BRACK@[82; 83) "]"
              WHITESPACE@[83; 92) "\n        "
              COMMENT@[92; 122) "//! Nor are ModuleDoc ..."
              WHITESPACE@[122; 127) "\n    "
@@ -57,26 +59,30 @@ SOURCE_FILE@[0; 350)
                ATTR@[152; 171)
                  POUND@[152; 153) "#"
                  EXCL@[153; 154) "!"
-                  TOKEN_TREE@[154; 171)
+                  L_BRACK@[154; 155) "["
-                    L_BRACK@[154; 155) "["
+                  PATH@[155; 158)
-                    IDENT@[155; 158) "doc"
+                    PATH_SEGMENT@[155; 158)
-                    TOKEN_TREE@[158; 170)
+                      NAME_REF@[155; 158)
-                      L_PAREN@[158; 159) "("
+                        IDENT@[155; 158) "doc"
-                      STRING@[159; 169) "\"Nor here\""
+                  TOKEN_TREE@[158; 170)
-                      R_PAREN@[169; 170) ")"
+                    L_PAREN@[158; 159) "("
-                    R_BRACK@[170; 171) "]"
+                    STRING@[159; 169) "\"Nor here\""
+                    R_PAREN@[169; 170) ")"
+                  R_BRACK@[170; 171) "]"
                WHITESPACE@[171; 180) "\n        "
                ATTR@[180; 212)
                  POUND@[180; 181) "#"
                  EXCL@[181; 182) "!"
-                  TOKEN_TREE@[182; 212)
+                  L_BRACK@[182; 183) "["
-                    L_BRACK@[182; 183) "["
+                  PATH@[183; 186)
-                    IDENT@[183; 186) "doc"
+                    PATH_SEGMENT@[183; 186)
-                    TOKEN_TREE@[186; 211)
+                      NAME_REF@[183; 186)
-                      L_PAREN@[186; 187) "("
+                        IDENT@[183; 186) "doc"
-                      STRING@[187; 210) "\"We error on each attr\""
+                  TOKEN_TREE@[186; 211)
-                      R_PAREN@[210; 211) ")"
+                    L_PAREN@[186; 187) "("
-                    R_BRACK@[211; 212) "]"
+                    STRING@[187; 210) "\"We error on each attr\""
+                    R_PAREN@[210; 211) ")"
+                  R_BRACK@[211; 212) "]"
                WHITESPACE@[212; 221) "\n        "
                COMMENT@[221; 251) "//! Nor are ModuleDoc ..."
                WHITESPACE@[251; 256) "\n    "
@@ -96,14 +102,16 @@ SOURCE_FILE@[0; 350)
              ATTR@[283; 302)
                POUND@[283; 284) "#"
                EXCL@[284; 285) "!"
-                TOKEN_TREE@[285; 302)
+                L_BRACK@[285; 286) "["
-                  L_BRACK@[285; 286) "["
+                PATH@[286; 289)
-                  IDENT@[286; 289) "doc"
+                  PATH_SEGMENT@[286; 289)
-                  TOKEN_TREE@[289; 301)
+                    NAME_REF@[286; 289)
-                    L_PAREN@[289; 290) "("
+                      IDENT@[286; 289) "doc"
-                    STRING@[290; 300) "\"Nor here\""
+                TOKEN_TREE@[289; 301)
-                    R_PAREN@[300; 301) ")"
+                  L_PAREN@[289; 290) "("
-                  R_BRACK@[301; 302) "]"
+                  STRING@[290; 300) "\"Nor here\""
+                  R_PAREN@[300; 301) ")"
+                R_BRACK@[301; 302) "]"
              WHITESPACE@[302; 311) "\n        "
              COMMENT@[311; 341) "//! Nor are ModuleDoc ..."
              WHITESPACE@[341; 346) "\n    "
diff --git a/crates/ra_syntax/test_data/parser/err/0032_match_arms_inner_attrs.txt b/crates/ra_syntax/test_data/parser/err/0032_match_arms_inner_attrs.txt
index 1344fcbc2..dbc0081ac 100644
--- a/crates/ra_syntax/test_data/parser/err/0032_match_arms_inner_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/err/0032_match_arms_inner_attrs.txt
@@ -135,14 +135,16 @@ SOURCE_FILE@[0; 293)
            MATCH_ARM@[210; 250)
              ATTR@[210; 222)
                POUND@[210; 211) "#"
-                TOKEN_TREE@[211; 222)
+                L_BRACK@[211; 212) "["
-                  L_BRACK@[211; 212) "["
+                PATH@[212; 215)
-                  IDENT@[212; 215) "cfg"
+                  PATH_SEGMENT@[212; 215)
-                  TOKEN_TREE@[215; 221)
+                    NAME_REF@[212; 215)
-                    L_PAREN@[215; 216) "("
+                      IDENT@[212; 215) "cfg"
-                    IDENT@[216; 220) "test"
+                TOKEN_TREE@[215; 221)
-                    R_PAREN@[220; 221) ")"
+                  L_PAREN@[215; 216) "("
-                  R_BRACK@[221; 222) "]"
+                  IDENT@[216; 220) "test"
+                  R_PAREN@[220; 221) ")"
+                R_BRACK@[221; 222) "]"
              WHITESPACE@[222; 231) "\n        "
              ATTR@[231; 232)
                POUND@[231; 232) "#"
diff --git a/crates/ra_syntax/test_data/parser/err/0033_match_arms_outer_attrs.txt b/crates/ra_syntax/test_data/parser/err/0033_match_arms_outer_attrs.txt
index b65cc3de3..fd5ccc3f2 100644
--- a/crates/ra_syntax/test_data/parser/err/0033_match_arms_outer_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/err/0033_match_arms_outer_attrs.txt
@@ -47,14 +47,16 @@ SOURCE_FILE@[0; 89)
            MATCH_ARM@[68; 80)
              ATTR@[68; 80)
                POUND@[68; 69) "#"
-                TOKEN_TREE@[69; 80)
+                L_BRACK@[69; 70) "["
-                  L_BRACK@[69; 70) "["
+                PATH@[70; 73)
-                  IDENT@[70; 73) "cfg"
+                  PATH_SEGMENT@[70; 73)
-                  TOKEN_TREE@[73; 79)
+                    NAME_REF@[70; 73)
-                    L_PAREN@[73; 74) "("
+                      IDENT@[70; 73) "cfg"
-                    IDENT@[74; 78) "test"
+                TOKEN_TREE@[73; 79)
-                    R_PAREN@[78; 79) ")"
+                  L_PAREN@[73; 74) "("
-                  R_BRACK@[79; 80) "]"
+                  IDENT@[74; 78) "test"
+                  R_PAREN@[78; 79) ")"
+                R_BRACK@[79; 80) "]"
            WHITESPACE@[80; 85) "\n    "
            R_CURLY@[85; 86) "}"
        WHITESPACE@[86; 87) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.txt b/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
index eab9f5b91..2ca5b8f32 100644
--- a/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
+++ b/crates/ra_syntax/test_data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
@@ -15,10 +15,12 @@ SOURCE_FILE@[0; 48)
        EXPR_STMT@[14; 25)
          ATTR@[14; 18)
            POUND@[14; 15) "#"
-            TOKEN_TREE@[15; 18)
+            L_BRACK@[15; 16) "["
-              L_BRACK@[15; 16) "["
+            PATH@[16; 17)
-              IDENT@[16; 17) "A"
+              PATH_SEGMENT@[16; 17)
-              R_BRACK@[17; 18) "]"
+                NAME_REF@[16; 17)
+                  IDENT@[16; 17) "A"
+            R_BRACK@[17; 18) "]"
          WHITESPACE@[18; 19) " "
          BIN_EXPR@[19; 24)
            LITERAL@[19; 20)
@@ -33,10 +35,12 @@ SOURCE_FILE@[0; 48)
        EXPR_STMT@[29; 45)
          ATTR@[29; 33)
            POUND@[29; 30) "#"
-            TOKEN_TREE@[30; 33)
+            L_BRACK@[30; 31) "["
-              L_BRACK@[30; 31) "["
+            PATH@[31; 32)
-              IDENT@[31; 32) "B"
+              PATH_SEGMENT@[31; 32)
-              R_BRACK@[32; 33) "]"
+                NAME_REF@[31; 32)
+                  IDENT@[31; 32) "B"
+            R_BRACK@[32; 33) "]"
          WHITESPACE@[33; 34) " "
          IF_EXPR@[34; 44)
            IF_KW@[34; 36) "if"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.rs b/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.rs
index 293046a04..2f8188160 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.rs
@@ -1,4 +1,5 @@
 fn foo() {
    while true {};
    while let Some(x) = it.next() {};
+    while { true } {};
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.txt b/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.txt
index 9b43d624c..a6e14a114 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0031_while_expr.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 70)
+SOURCE_FILE@[0; 93)
-  FN_DEF@[0; 69)
+  FN_DEF@[0; 92)
    FN_KW@[0; 2) "fn"
    WHITESPACE@[2; 3) " "
    NAME@[3; 6)
@@ -8,8 +8,8 @@ SOURCE_FILE@[0; 70)
      L_PAREN@[6; 7) "("
      R_PAREN@[7; 8) ")"
    WHITESPACE@[8; 9) " "
-    BLOCK_EXPR@[9; 69)
+    BLOCK_EXPR@[9; 92)
-      BLOCK@[9; 69)
+      BLOCK@[9; 92)
        L_CURLY@[9; 10) "{"
        WHITESPACE@[10; 15) "\n    "
        EXPR_STMT@[15; 29)
@@ -64,6 +64,26 @@ SOURCE_FILE@[0; 70)
                L_CURLY@[64; 65) "{"
                R_CURLY@[65; 66) "}"
          SEMI@[66; 67) ";"
-        WHITESPACE@[67; 68) "\n"
+        WHITESPACE@[67; 72) "\n    "
-        R_CURLY@[68; 69) "}"
+        EXPR_STMT@[72; 90)
-  WHITESPACE@[69; 70) "\n"
+          WHILE_EXPR@[72; 89)
+            WHILE_KW@[72; 77) "while"
+            WHITESPACE@[77; 78) " "
+            CONDITION@[78; 86)
+              BLOCK_EXPR@[78; 86)
+                BLOCK@[78; 86)
+                  L_CURLY@[78; 79) "{"
+                  WHITESPACE@[79; 80) " "
+                  LITERAL@[80; 84)
+                    TRUE_KW@[80; 84) "true"
+                  WHITESPACE@[84; 85) " "
+                  R_CURLY@[85; 86) "}"
+            WHITESPACE@[86; 87) " "
+            BLOCK_EXPR@[87; 89)
+              BLOCK@[87; 89)
+                L_CURLY@[87; 88) "{"
+                R_CURLY@[88; 89) "}"
+          SEMI@[89; 90) ";"
+        WHITESPACE@[90; 91) "\n"
+        R_CURLY@[91; 92) "}"
+  WHITESPACE@[92; 93) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0054_record_field_attrs.txt b/crates/ra_syntax/test_data/parser/inline/ok/0054_record_field_attrs.txt
index 56aeba768..731c31f76 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0054_record_field_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0054_record_field_attrs.txt
@@ -11,18 +11,20 @@ SOURCE_FILE@[0; 64)
      RECORD_FIELD_DEF@[15; 60)
        ATTR@[15; 43)
          POUND@[15; 16) "#"
-          TOKEN_TREE@[16; 43)
+          L_BRACK@[16; 17) "["
-            L_BRACK@[16; 17) "["
+          PATH@[17; 22)
-            IDENT@[17; 22) "serde"
+            PATH_SEGMENT@[17; 22)
-            TOKEN_TREE@[22; 42)
+              NAME_REF@[17; 22)
-              L_PAREN@[22; 23) "("
+                IDENT@[17; 22) "serde"
-              IDENT@[23; 27) "with"
+          TOKEN_TREE@[22; 42)
-              WHITESPACE@[27; 28) " "
+            L_PAREN@[22; 23) "("
-              EQ@[28; 29) "="
+            IDENT@[23; 27) "with"
-              WHITESPACE@[29; 30) " "
+            WHITESPACE@[27; 28) " "
-              STRING@[30; 41) "\"url_serde\""
+            EQ@[28; 29) "="
-              R_PAREN@[41; 42) ")"
+            WHITESPACE@[29; 30) " "
-            R_BRACK@[42; 43) "]"
+            STRING@[30; 41) "\"url_serde\""
+            R_PAREN@[41; 42) ")"
+          R_BRACK@[42; 43) "]"
        WHITESPACE@[43; 48) "\n    "
        VISIBILITY@[48; 51)
          PUB_KW@[48; 51) "pub"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.rs b/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.rs
index 4b0d9af89..40f227ba3 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.rs
@@ -3,4 +3,5 @@ fn foo() {
    if true {} else {};
    if true {} else if false {} else {};
    if S {};
+    if { true } { } else { };
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.txt b/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.txt
index 14ea91fd2..2ace3c8ee 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0064_if_expr.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 107)
+SOURCE_FILE@[0; 137)
-  FN_DEF@[0; 106)
+  FN_DEF@[0; 136)
    FN_KW@[0; 2) "fn"
    WHITESPACE@[2; 3) " "
    NAME@[3; 6)
@@ -8,8 +8,8 @@ SOURCE_FILE@[0; 107)
      L_PAREN@[6; 7) "("
      R_PAREN@[7; 8) ")"
    WHITESPACE@[8; 9) " "
-    BLOCK_EXPR@[9; 106)
+    BLOCK_EXPR@[9; 136)
-      BLOCK@[9; 106)
+      BLOCK@[9; 136)
        L_CURLY@[9; 10) "{"
        WHITESPACE@[10; 15) "\n    "
        EXPR_STMT@[15; 26)
@@ -98,6 +98,35 @@ SOURCE_FILE@[0; 107)
                L_CURLY@[101; 102) "{"
                R_CURLY@[102; 103) "}"
          SEMI@[103; 104) ";"
-        WHITESPACE@[104; 105) "\n"
+        WHITESPACE@[104; 109) "\n    "
-        R_CURLY@[105; 106) "}"
+        EXPR_STMT@[109; 134)
-  WHITESPACE@[106; 107) "\n"
+          IF_EXPR@[109; 133)
+            IF_KW@[109; 111) "if"
+            WHITESPACE@[111; 112) " "
+            CONDITION@[112; 120)
+              BLOCK_EXPR@[112; 120)
+                BLOCK@[112; 120)
+                  L_CURLY@[112; 113) "{"
+                  WHITESPACE@[113; 114) " "
+                  LITERAL@[114; 118)
+                    TRUE_KW@[114; 118) "true"
+                  WHITESPACE@[118; 119) " "
+                  R_CURLY@[119; 120) "}"
+            WHITESPACE@[120; 121) " "
+            BLOCK_EXPR@[121; 124)
+              BLOCK@[121; 124)
+                L_CURLY@[121; 122) "{"
+                WHITESPACE@[122; 123) " "
+                R_CURLY@[123; 124) "}"
+            WHITESPACE@[124; 125) " "
+            ELSE_KW@[125; 129) "else"
+            WHITESPACE@[129; 130) " "
+            BLOCK_EXPR@[130; 133)
+              BLOCK@[130; 133)
+                L_CURLY@[130; 131) "{"
+                WHITESPACE@[131; 132) " "
+                R_CURLY@[132; 133) "}"
+          SEMI@[133; 134) ";"
+        WHITESPACE@[134; 135) "\n"
+        R_CURLY@[135; 136) "}"
+  WHITESPACE@[136; 137) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.rs b/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.rs
index c9205dfa3..c4021dc10 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.rs
@@ -1,4 +1,6 @@
 fn foo() {
    match () { };
    match S {};
+    match { } { _ => () };
+    match { S {} } {};
 }
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.txt b/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.txt
index f62b6c6d5..0af668056 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0071_match_expr.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 47)
+SOURCE_FILE@[0; 97)
-  FN_DEF@[0; 46)
+  FN_DEF@[0; 96)
    FN_KW@[0; 2) "fn"
    WHITESPACE@[2; 3) " "
    NAME@[3; 6)
@@ -8,8 +8,8 @@ SOURCE_FILE@[0; 47)
      L_PAREN@[6; 7) "("
      R_PAREN@[7; 8) ")"
    WHITESPACE@[8; 9) " "
-    BLOCK_EXPR@[9; 46)
+    BLOCK_EXPR@[9; 96)
-      BLOCK@[9; 46)
+      BLOCK@[9; 96)
        L_CURLY@[9; 10) "{"
        WHITESPACE@[10; 15) "\n    "
        EXPR_STMT@[15; 28)
@@ -40,6 +40,57 @@ SOURCE_FILE@[0; 47)
              L_CURLY@[41; 42) "{"
              R_CURLY@[42; 43) "}"
          SEMI@[43; 44) ";"
-        WHITESPACE@[44; 45) "\n"
+        WHITESPACE@[44; 49) "\n    "
-        R_CURLY@[45; 46) "}"
+        EXPR_STMT@[49; 71)
-  WHITESPACE@[46; 47) "\n"
+          MATCH_EXPR@[49; 70)
+            MATCH_KW@[49; 54) "match"
+            WHITESPACE@[54; 55) " "
+            BLOCK_EXPR@[55; 58)
+              BLOCK@[55; 58)
+                L_CURLY@[55; 56) "{"
+                WHITESPACE@[56; 57) " "
+                R_CURLY@[57; 58) "}"
+            WHITESPACE@[58; 59) " "
+            MATCH_ARM_LIST@[59; 70)
+              L_CURLY@[59; 60) "{"
+              WHITESPACE@[60; 61) " "
+              MATCH_ARM@[61; 68)
+                PLACEHOLDER_PAT@[61; 62)
+                  UNDERSCORE@[61; 62) "_"
+                WHITESPACE@[62; 63) " "
+                FAT_ARROW@[63; 65) "=>"
+                WHITESPACE@[65; 66) " "
+                TUPLE_EXPR@[66; 68)
+                  L_PAREN@[66; 67) "("
+                  R_PAREN@[67; 68) ")"
+              WHITESPACE@[68; 69) " "
+              R_CURLY@[69; 70) "}"
+          SEMI@[70; 71) ";"
+        WHITESPACE@[71; 76) "\n    "
+        EXPR_STMT@[76; 94)
+          MATCH_EXPR@[76; 93)
+            MATCH_KW@[76; 81) "match"
+            WHITESPACE@[81; 82) " "
+            BLOCK_EXPR@[82; 90)
+              BLOCK@[82; 90)
+                L_CURLY@[82; 83) "{"
+                WHITESPACE@[83; 84) " "
+                RECORD_LIT@[84; 88)
+                  PATH@[84; 85)
+                    PATH_SEGMENT@[84; 85)
+                      NAME_REF@[84; 85)
+                        IDENT@[84; 85) "S"
+                  WHITESPACE@[85; 86) " "
+                  RECORD_FIELD_LIST@[86; 88)
+                    L_CURLY@[86; 87) "{"
+                    R_CURLY@[87; 88) "}"
+                WHITESPACE@[88; 89) " "
+                R_CURLY@[89; 90) "}"
+            WHITESPACE@[90; 91) " "
+            MATCH_ARM_LIST@[91; 93)
+              L_CURLY@[91; 92) "{"
+              R_CURLY@[92; 93) "}"
+          SEMI@[93; 94) ";"
+        WHITESPACE@[94; 95) "\n"
+        R_CURLY@[95; 96) "}"
+  WHITESPACE@[96; 97) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.rs b/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.rs
index c39fe8e68..e7b7cfc6b 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.rs
@@ -1 +1,5 @@
-fn foo() { let x = 1..; }
+fn foo() {
+    let x = 1..;
+    match 1.. { _ => () };
+    match a.b()..S { _ => () };
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.txt b/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.txt
index f3c292f5e..9f8a6b0f6 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0080_postfix_range.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 26)
+SOURCE_FILE@[0; 89)
-  FN_DEF@[0; 25)
+  FN_DEF@[0; 88)
    FN_KW@[0; 2) "fn"
    WHITESPACE@[2; 3) " "
    NAME@[3; 6)
@@ -8,24 +8,89 @@ SOURCE_FILE@[0; 26)
      L_PAREN@[6; 7) "("
      R_PAREN@[7; 8) ")"
    WHITESPACE@[8; 9) " "
-    BLOCK_EXPR@[9; 25)
+    BLOCK_EXPR@[9; 88)
-      BLOCK@[9; 25)
+      BLOCK@[9; 88)
        L_CURLY@[9; 10) "{"
-        WHITESPACE@[10; 11) " "
+        WHITESPACE@[10; 15) "\n    "
-        LET_STMT@[11; 23)
+        LET_STMT@[15; 27)
-          LET_KW@[11; 14) "let"
+          LET_KW@[15; 18) "let"
-          WHITESPACE@[14; 15) " "
-          BIND_PAT@[15; 16)
-            NAME@[15; 16)
-              IDENT@[15; 16) "x"
-          WHITESPACE@[16; 17) " "
-          EQ@[17; 18) "="
          WHITESPACE@[18; 19) " "
-          RANGE_EXPR@[19; 22)
+          BIND_PAT@[19; 20)
-            LITERAL@[19; 20)
+            NAME@[19; 20)
-              INT_NUMBER@[19; 20) "1"
+              IDENT@[19; 20) "x"
-            DOTDOT@[20; 22) ".."
+          WHITESPACE@[20; 21) " "
-          SEMI@[22; 23) ";"
+          EQ@[21; 22) "="
-        WHITESPACE@[23; 24) " "
+          WHITESPACE@[22; 23) " "
-        R_CURLY@[24; 25) "}"
+          RANGE_EXPR@[23; 26)
-  WHITESPACE@[25; 26) "\n"
+            LITERAL@[23; 24)
+              INT_NUMBER@[23; 24) "1"
+            DOTDOT@[24; 26) ".."
+          SEMI@[26; 27) ";"
+        WHITESPACE@[27; 32) "\n    "
+        EXPR_STMT@[32; 54)
+          MATCH_EXPR@[32; 53)
+            MATCH_KW@[32; 37) "match"
+            WHITESPACE@[37; 38) " "
+            RANGE_EXPR@[38; 41)
+              LITERAL@[38; 39)
+                INT_NUMBER@[38; 39) "1"
+              DOTDOT@[39; 41) ".."
+            WHITESPACE@[41; 42) " "
+            MATCH_ARM_LIST@[42; 53)
+              L_CURLY@[42; 43) "{"
+              WHITESPACE@[43; 44) " "
+              MATCH_ARM@[44; 51)
+                PLACEHOLDER_PAT@[44; 45)
+                  UNDERSCORE@[44; 45) "_"
+                WHITESPACE@[45; 46) " "
+                FAT_ARROW@[46; 48) "=>"
+                WHITESPACE@[48; 49) " "
+                TUPLE_EXPR@[49; 51)
+                  L_PAREN@[49; 50) "("
+                  R_PAREN@[50; 51) ")"
+              WHITESPACE@[51; 52) " "
+              R_CURLY@[52; 53) "}"
+          SEMI@[53; 54) ";"
+        WHITESPACE@[54; 59) "\n    "
+        EXPR_STMT@[59; 86)
+          MATCH_EXPR@[59; 85)
+            MATCH_KW@[59; 64) "match"
+            WHITESPACE@[64; 65) " "
+            RANGE_EXPR@[65; 73)
+              METHOD_CALL_EXPR@[65; 70)
+                PATH_EXPR@[65; 66)
+                  PATH@[65; 66)
+                    PATH_SEGMENT@[65; 66)
+                      NAME_REF@[65; 66)
+                        IDENT@[65; 66) "a"
+                DOT@[66; 67) "."
+                NAME_REF@[67; 68)
+                  IDENT@[67; 68) "b"
+                ARG_LIST@[68; 70)
+                  L_PAREN@[68; 69) "("
+                  R_PAREN@[69; 70) ")"
+              DOTDOT@[70; 72) ".."
+              PATH_EXPR@[72; 73)
+                PATH@[72; 73)
+                  PATH_SEGMENT@[72; 73)
+                    NAME_REF@[72; 73)
+                      IDENT@[72; 73) "S"
+            WHITESPACE@[73; 74) " "
+            MATCH_ARM_LIST@[74; 85)
+              L_CURLY@[74; 75) "{"
+              WHITESPACE@[75; 76) " "
+              MATCH_ARM@[76; 83)
+                PLACEHOLDER_PAT@[76; 77)
+                  UNDERSCORE@[76; 77) "_"
+                WHITESPACE@[77; 78) " "
+                FAT_ARROW@[78; 80) "=>"
+                WHITESPACE@[80; 81) " "
+                TUPLE_EXPR@[81; 83)
+                  L_PAREN@[81; 82) "("
+                  R_PAREN@[82; 83) ")"
+              WHITESPACE@[83; 84) " "
+              R_CURLY@[84; 85) "}"
+          SEMI@[85; 86) ";"
+        WHITESPACE@[86; 87) "\n"
+        R_CURLY@[87; 88) "}"
+  WHITESPACE@[88; 89) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0115_tuple_field_attrs.txt b/crates/ra_syntax/test_data/parser/inline/ok/0115_tuple_field_attrs.txt
index cb6d9f76d..8fe15d8e2 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0115_tuple_field_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0115_tuple_field_attrs.txt
@@ -11,18 +11,20 @@ SOURCE_FILE@[0; 60)
      TUPLE_FIELD_DEF@[15; 55)
        ATTR@[15; 43)
          POUND@[15; 16) "#"
-          TOKEN_TREE@[16; 43)
+          L_BRACK@[16; 17) "["
-            L_BRACK@[16; 17) "["
+          PATH@[17; 22)
-            IDENT@[17; 22) "serde"
+            PATH_SEGMENT@[17; 22)
-            TOKEN_TREE@[22; 42)
+              NAME_REF@[17; 22)
-              L_PAREN@[22; 23) "("
+                IDENT@[17; 22) "serde"
-              IDENT@[23; 27) "with"
+          TOKEN_TREE@[22; 42)
-              WHITESPACE@[27; 28) " "
+            L_PAREN@[22; 23) "("
-              EQ@[28; 29) "="
+            IDENT@[23; 27) "with"
-              WHITESPACE@[29; 30) " "
+            WHITESPACE@[27; 28) " "
-              STRING@[30; 41) "\"url_serde\""
+            EQ@[28; 29) "="
-              R_PAREN@[41; 42) ")"
+            WHITESPACE@[29; 30) " "
-            R_BRACK@[42; 43) "]"
+            STRING@[30; 41) "\"url_serde\""
+            R_PAREN@[41; 42) ")"
+          R_BRACK@[42; 43) "]"
        WHITESPACE@[43; 48) "\n    "
        VISIBILITY@[48; 51)
          PUB_KW@[48; 51) "pub"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0118_impl_inner_attributes.txt b/crates/ra_syntax/test_data/parser/inline/ok/0118_impl_inner_attributes.txt
index 0ef3eeb75..0e9e9b95b 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0118_impl_inner_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0118_impl_inner_attributes.txt
@@ -25,14 +25,16 @@ SOURCE_FILE@[0; 94)
      ATTR@[54; 91)
        POUND@[54; 55) "#"
        EXCL@[55; 56) "!"
-        TOKEN_TREE@[56; 91)
+        L_BRACK@[56; 57) "["
-          L_BRACK@[56; 57) "["
+        PATH@[57; 60)
-          IDENT@[57; 60) "doc"
+          PATH_SEGMENT@[57; 60)
-          TOKEN_TREE@[60; 90)
+            NAME_REF@[57; 60)
-            L_PAREN@[60; 61) "("
+              IDENT@[57; 60) "doc"
-            STRING@[61; 89) "\"This is also a doc c ..."
+        TOKEN_TREE@[60; 90)
-            R_PAREN@[89; 90) ")"
+          L_PAREN@[60; 61) "("
-          R_BRACK@[90; 91) "]"
+          STRING@[61; 89) "\"This is also a doc c ..."
+          R_PAREN@[89; 90) ")"
+        R_BRACK@[90; 91) "]"
      WHITESPACE@[91; 92) "\n"
      R_CURLY@[92; 93) "}"
  WHITESPACE@[93; 94) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0120_match_arms_inner_attribute.txt b/crates/ra_syntax/test_data/parser/inline/ok/0120_match_arms_inner_attribute.txt
index 3bbeb62bc..640e0640f 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0120_match_arms_inner_attribute.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0120_match_arms_inner_attribute.txt
@@ -25,38 +25,44 @@ SOURCE_FILE@[0; 139)
            ATTR@[34; 60)
              POUND@[34; 35) "#"
              EXCL@[35; 36) "!"
-              TOKEN_TREE@[36; 60)
+              L_BRACK@[36; 37) "["
-                L_BRACK@[36; 37) "["
+              PATH@[37; 40)
-                IDENT@[37; 40) "doc"
+                PATH_SEGMENT@[37; 40)
-                TOKEN_TREE@[40; 59)
+                  NAME_REF@[37; 40)
-                  L_PAREN@[40; 41) "("
+                    IDENT@[37; 40) "doc"
-                  STRING@[41; 58) "\"Inner attribute\""
+              TOKEN_TREE@[40; 59)
-                  R_PAREN@[58; 59) ")"
+                L_PAREN@[40; 41) "("
-                R_BRACK@[59; 60) "]"
+                STRING@[41; 58) "\"Inner attribute\""
+                R_PAREN@[58; 59) ")"
+              R_BRACK@[59; 60) "]"
            WHITESPACE@[60; 69) "\n        "
            ATTR@[69; 86)
              POUND@[69; 70) "#"
              EXCL@[70; 71) "!"
-              TOKEN_TREE@[71; 86)
+              L_BRACK@[71; 72) "["
-                L_BRACK@[71; 72) "["
+              PATH@[72; 75)
-                IDENT@[72; 75) "doc"
+                PATH_SEGMENT@[72; 75)
-                TOKEN_TREE@[75; 85)
+                  NAME_REF@[72; 75)
-                  L_PAREN@[75; 76) "("
+                    IDENT@[72; 75) "doc"
-                  STRING@[76; 84) "\"Can be\""
+              TOKEN_TREE@[75; 85)
-                  R_PAREN@[84; 85) ")"
+                L_PAREN@[75; 76) "("
-                R_BRACK@[85; 86) "]"
+                STRING@[76; 84) "\"Can be\""
+                R_PAREN@[84; 85) ")"
+              R_BRACK@[85; 86) "]"
            WHITESPACE@[86; 95) "\n        "
            ATTR@[95; 113)
              POUND@[95; 96) "#"
              EXCL@[96; 97) "!"
-              TOKEN_TREE@[97; 113)
+              L_BRACK@[97; 98) "["
-                L_BRACK@[97; 98) "["
+              PATH@[98; 101)
-                IDENT@[98; 101) "doc"
+                PATH_SEGMENT@[98; 101)
-                TOKEN_TREE@[101; 112)
+                  NAME_REF@[98; 101)
-                  L_PAREN@[101; 102) "("
+                    IDENT@[98; 101) "doc"
-                  STRING@[102; 111) "\"Stacked\""
+              TOKEN_TREE@[101; 112)
-                  R_PAREN@[111; 112) ")"
+                L_PAREN@[101; 102) "("
-                R_BRACK@[112; 113) "]"
+                STRING@[102; 111) "\"Stacked\""
+                R_PAREN@[111; 112) ")"
+              R_BRACK@[112; 113) "]"
            WHITESPACE@[113; 122) "\n        "
            MATCH_ARM@[122; 129)
              PLACEHOLDER_PAT@[122; 123)
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0121_match_arms_outer_attributes.txt b/crates/ra_syntax/test_data/parser/inline/ok/0121_match_arms_outer_attributes.txt
index 5fd0adfc2..ff380b448 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0121_match_arms_outer_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0121_match_arms_outer_attributes.txt
@@ -25,18 +25,20 @@ SOURCE_FILE@[0; 259)
            MATCH_ARM@[34; 74)
              ATTR@[34; 58)
                POUND@[34; 35) "#"
-                TOKEN_TREE@[35; 58)
+                L_BRACK@[35; 36) "["
-                  L_BRACK@[35; 36) "["
+                PATH@[36; 39)
-                  IDENT@[36; 39) "cfg"
+                  PATH_SEGMENT@[36; 39)
-                  TOKEN_TREE@[39; 57)
+                    NAME_REF@[36; 39)
-                    L_PAREN@[39; 40) "("
+                      IDENT@[36; 39) "cfg"
-                    IDENT@[40; 47) "feature"
+                TOKEN_TREE@[39; 57)
-                    WHITESPACE@[47; 48) " "
+                  L_PAREN@[39; 40) "("
-                    EQ@[48; 49) "="
+                  IDENT@[40; 47) "feature"
-                    WHITESPACE@[49; 50) " "
+                  WHITESPACE@[47; 48) " "
-                    STRING@[50; 56) "\"some\""
+                  EQ@[48; 49) "="
-                    R_PAREN@[56; 57) ")"
+                  WHITESPACE@[49; 50) " "
-                  R_BRACK@[57; 58) "]"
+                  STRING@[50; 56) "\"some\""
+                  R_PAREN@[56; 57) ")"
+                R_BRACK@[57; 58) "]"
              WHITESPACE@[58; 67) "\n        "
              PLACEHOLDER_PAT@[67; 68)
                UNDERSCORE@[67; 68) "_"
@@ -51,18 +53,20 @@ SOURCE_FILE@[0; 259)
            MATCH_ARM@[84; 125)
              ATTR@[84; 109)
                POUND@[84; 85) "#"
-                TOKEN_TREE@[85; 109)
+                L_BRACK@[85; 86) "["
-                  L_BRACK@[85; 86) "["
+                PATH@[86; 89)
-                  IDENT@[86; 89) "cfg"
+                  PATH_SEGMENT@[86; 89)
-                  TOKEN_TREE@[89; 108)
+                    NAME_REF@[86; 89)
-                    L_PAREN@[89; 90) "("
+                      IDENT@[86; 89) "cfg"
-                    IDENT@[90; 97) "feature"
+                TOKEN_TREE@[89; 108)
-                    WHITESPACE@[97; 98) " "
+                  L_PAREN@[89; 90) "("
-                    EQ@[98; 99) "="
+                  IDENT@[90; 97) "feature"
-                    WHITESPACE@[99; 100) " "
+                  WHITESPACE@[97; 98) " "
-                    STRING@[100; 107) "\"other\""
+                  EQ@[98; 99) "="
-                    R_PAREN@[107; 108) ")"
+                  WHITESPACE@[99; 100) " "
-                  R_BRACK@[108; 109) "]"
+                  STRING@[100; 107) "\"other\""
+                  R_PAREN@[107; 108) ")"
+                R_BRACK@[108; 109) "]"
              WHITESPACE@[109; 118) "\n        "
              PLACEHOLDER_PAT@[118; 119)
                UNDERSCORE@[118; 119) "_"
@@ -77,48 +81,54 @@ SOURCE_FILE@[0; 259)
            MATCH_ARM@[135; 249)
              ATTR@[135; 159)
                POUND@[135; 136) "#"
-                TOKEN_TREE@[136; 159)
+                L_BRACK@[136; 137) "["
-                  L_BRACK@[136; 137) "["
+                PATH@[137; 140)
-                  IDENT@[137; 140) "cfg"
+                  PATH_SEGMENT@[137; 140)
-                  TOKEN_TREE@[140; 158)
+                    NAME_REF@[137; 140)
-                    L_PAREN@[140; 141) "("
+                      IDENT@[137; 140) "cfg"
-                    IDENT@[141; 148) "feature"
+                TOKEN_TREE@[140; 158)
-                    WHITESPACE@[148; 149) " "
+                  L_PAREN@[140; 141) "("
-                    EQ@[149; 150) "="
+                  IDENT@[141; 148) "feature"
-                    WHITESPACE@[150; 151) " "
+                  WHITESPACE@[148; 149) " "
-                    STRING@[151; 157) "\"many\""
+                  EQ@[149; 150) "="
-                    R_PAREN@[157; 158) ")"
+                  WHITESPACE@[150; 151) " "
-                  R_BRACK@[158; 159) "]"
+                  STRING@[151; 157) "\"many\""
+                  R_PAREN@[157; 158) ")"
+                R_BRACK@[158; 159) "]"
              WHITESPACE@[159; 168) "\n        "
              ATTR@[168; 198)
                POUND@[168; 169) "#"
-                TOKEN_TREE@[169; 198)
+                L_BRACK@[169; 170) "["
-                  L_BRACK@[169; 170) "["
+                PATH@[170; 173)
-                  IDENT@[170; 173) "cfg"
+                  PATH_SEGMENT@[170; 173)
-                  TOKEN_TREE@[173; 197)
+                    NAME_REF@[170; 173)
-                    L_PAREN@[173; 174) "("
+                      IDENT@[170; 173) "cfg"
-                    IDENT@[174; 181) "feature"
+                TOKEN_TREE@[173; 197)
-                    WHITESPACE@[181; 182) " "
+                  L_PAREN@[173; 174) "("
-                    EQ@[182; 183) "="
+                  IDENT@[174; 181) "feature"
-                    WHITESPACE@[183; 184) " "
+                  WHITESPACE@[181; 182) " "
-                    STRING@[184; 196) "\"attributes\""
+                  EQ@[182; 183) "="
-                    R_PAREN@[196; 197) ")"
+                  WHITESPACE@[183; 184) " "
-                  R_BRACK@[197; 198) "]"
+                  STRING@[184; 196) "\"attributes\""
+                  R_PAREN@[196; 197) ")"
+                R_BRACK@[197; 198) "]"
              WHITESPACE@[198; 207) "\n        "
              ATTR@[207; 233)
                POUND@[207; 208) "#"
-                TOKEN_TREE@[208; 233)
+                L_BRACK@[208; 209) "["
-                  L_BRACK@[208; 209) "["
+                PATH@[209; 212)
-                  IDENT@[209; 212) "cfg"
+                  PATH_SEGMENT@[209; 212)
-                  TOKEN_TREE@[212; 232)
+                    NAME_REF@[209; 212)
-                    L_PAREN@[212; 213) "("
+                      IDENT@[209; 212) "cfg"
-                    IDENT@[213; 220) "feature"
+                TOKEN_TREE@[212; 232)
-                    WHITESPACE@[220; 221) " "
+                  L_PAREN@[212; 213) "("
-                    EQ@[221; 222) "="
+                  IDENT@[213; 220) "feature"
-                    WHITESPACE@[222; 223) " "
+                  WHITESPACE@[220; 221) " "
-                    STRING@[223; 231) "\"before\""
+                  EQ@[221; 222) "="
-                    R_PAREN@[231; 232) ")"
+                  WHITESPACE@[222; 223) " "
-                  R_BRACK@[232; 233) "]"
+                  STRING@[223; 231) "\"before\""
+                  R_PAREN@[231; 232) ")"
+                R_BRACK@[232; 233) "]"
              WHITESPACE@[233; 242) "\n        "
              PLACEHOLDER_PAT@[242; 243)
                UNDERSCORE@[242; 243) "_"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0122_generic_lifetime_type_attribute.txt b/crates/ra_syntax/test_data/parser/inline/ok/0122_generic_lifetime_type_attribute.txt
index bc7b68b90..a73ff9c90 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0122_generic_lifetime_type_attribute.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0122_generic_lifetime_type_attribute.txt
@@ -9,14 +9,16 @@ SOURCE_FILE@[0; 64)
      LIFETIME_PARAM@[7; 29)
        ATTR@[7; 26)
          POUND@[7; 8) "#"
-          TOKEN_TREE@[8; 26)
+          L_BRACK@[8; 9) "["
-            L_BRACK@[8; 9) "["
+          PATH@[9; 15)
-            IDENT@[9; 15) "derive"
+            PATH_SEGMENT@[9; 15)
-            TOKEN_TREE@[15; 25)
+              NAME_REF@[9; 15)
-              L_PAREN@[15; 16) "("
+                IDENT@[9; 15) "derive"
-              IDENT@[16; 24) "Lifetime"
+          TOKEN_TREE@[15; 25)
-              R_PAREN@[24; 25) ")"
+            L_PAREN@[15; 16) "("
-            R_BRACK@[25; 26) "]"
+            IDENT@[16; 24) "Lifetime"
+            R_PAREN@[24; 25) ")"
+          R_BRACK@[25; 26) "]"
        WHITESPACE@[26; 27) " "
        LIFETIME@[27; 29) "\'a"
      COMMA@[29; 30) ","
@@ -24,14 +26,16 @@ SOURCE_FILE@[0; 64)
      TYPE_PARAM@[31; 48)
        ATTR@[31; 46)
          POUND@[31; 32) "#"
-          TOKEN_TREE@[32; 46)
+          L_BRACK@[32; 33) "["
-            L_BRACK@[32; 33) "["
+          PATH@[33; 39)
-            IDENT@[33; 39) "derive"
+            PATH_SEGMENT@[33; 39)
-            TOKEN_TREE@[39; 45)
+              NAME_REF@[33; 39)
-              L_PAREN@[39; 40) "("
+                IDENT@[33; 39) "derive"
-              IDENT@[40; 44) "Type"
+          TOKEN_TREE@[39; 45)
-              R_PAREN@[44; 45) ")"
+            L_PAREN@[39; 40) "("
-            R_BRACK@[45; 46) "]"
+            IDENT@[40; 44) "Type"
+            R_PAREN@[44; 45) ")"
+          R_BRACK@[45; 46) "]"
        WHITESPACE@[46; 47) " "
        NAME@[47; 48)
          IDENT@[47; 48) "T"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0125_record_literal_field_with_attr.txt b/crates/ra_syntax/test_data/parser/inline/ok/0125_record_literal_field_with_attr.txt
index 37cc438d9..a36c3df0e 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0125_record_literal_field_with_attr.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0125_record_literal_field_with_attr.txt
@@ -24,14 +24,16 @@ SOURCE_FILE@[0; 46)
            RECORD_FIELD@[20; 41)
              ATTR@[20; 32)
                POUND@[20; 21) "#"
-                TOKEN_TREE@[21; 32)
+                L_BRACK@[21; 22) "["
-                  L_BRACK@[21; 22) "["
+                PATH@[22; 25)
-                  IDENT@[22; 25) "cfg"
+                  PATH_SEGMENT@[22; 25)
-                  TOKEN_TREE@[25; 31)
+                    NAME_REF@[22; 25)
-                    L_PAREN@[25; 26) "("
+                      IDENT@[22; 25) "cfg"
-                    IDENT@[26; 30) "test"
+                TOKEN_TREE@[25; 31)
-                    R_PAREN@[30; 31) ")"
+                  L_PAREN@[25; 26) "("
-                  R_BRACK@[31; 32) "]"
+                  IDENT@[26; 30) "test"
+                  R_PAREN@[30; 31) ")"
+                R_BRACK@[31; 32) "]"
              WHITESPACE@[32; 33) " "
              NAME_REF@[33; 38)
                IDENT@[33; 38) "field"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0126_attr_on_expr_stmt.txt b/crates/ra_syntax/test_data/parser/inline/ok/0126_attr_on_expr_stmt.txt
index 6bc0db077..5c311d18a 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0126_attr_on_expr_stmt.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0126_attr_on_expr_stmt.txt
@@ -15,10 +15,12 @@ SOURCE_FILE@[0; 82)
        EXPR_STMT@[15; 26)
          ATTR@[15; 19)
            POUND@[15; 16) "#"
-            TOKEN_TREE@[16; 19)
+            L_BRACK@[16; 17) "["
-              L_BRACK@[16; 17) "["
+            PATH@[17; 18)
-              IDENT@[17; 18) "A"
+              PATH_SEGMENT@[17; 18)
-              R_BRACK@[18; 19) "]"
+                NAME_REF@[17; 18)
+                  IDENT@[17; 18) "A"
+            R_BRACK@[18; 19) "]"
          WHITESPACE@[19; 20) " "
          CALL_EXPR@[20; 25)
            PATH_EXPR@[20; 23)
@@ -34,10 +36,12 @@ SOURCE_FILE@[0; 82)
        EXPR_STMT@[31; 42)
          ATTR@[31; 35)
            POUND@[31; 32) "#"
-            TOKEN_TREE@[32; 35)
+            L_BRACK@[32; 33) "["
-              L_BRACK@[32; 33) "["
+            PATH@[33; 34)
-              IDENT@[33; 34) "B"
+              PATH_SEGMENT@[33; 34)
-              R_BRACK@[34; 35) "]"
+                NAME_REF@[33; 34)
+                  IDENT@[33; 34) "B"
+            R_BRACK@[34; 35) "]"
          WHITESPACE@[35; 36) " "
          MACRO_CALL@[36; 42)
            PATH@[36; 39)
@@ -52,17 +56,21 @@ SOURCE_FILE@[0; 82)
        EXPR_STMT@[47; 59)
          ATTR@[47; 51)
            POUND@[47; 48) "#"
-            TOKEN_TREE@[48; 51)
+            L_BRACK@[48; 49) "["
-              L_BRACK@[48; 49) "["
+            PATH@[49; 50)
-              IDENT@[49; 50) "C"
+              PATH_SEGMENT@[49; 50)
-              R_BRACK@[50; 51) "]"
+                NAME_REF@[49; 50)
+                  IDENT@[49; 50) "C"
+            R_BRACK@[50; 51) "]"
          WHITESPACE@[51; 52) " "
          ATTR@[52; 56)
            POUND@[52; 53) "#"
-            TOKEN_TREE@[53; 56)
+            L_BRACK@[53; 54) "["
-              L_BRACK@[53; 54) "["
+            PATH@[54; 55)
-              IDENT@[54; 55) "D"
+              PATH_SEGMENT@[54; 55)
-              R_BRACK@[55; 56) "]"
+                NAME_REF@[54; 55)
+                  IDENT@[54; 55) "D"
+            R_BRACK@[55; 56) "]"
          WHITESPACE@[56; 57) " "
          BLOCK_EXPR@[57; 59)
            BLOCK@[57; 59)
@@ -72,10 +80,12 @@ SOURCE_FILE@[0; 82)
        EXPR_STMT@[64; 79)
          ATTR@[64; 68)
            POUND@[64; 65) "#"
-            TOKEN_TREE@[65; 68)
+            L_BRACK@[65; 66) "["
-              L_BRACK@[65; 66) "["
+            PATH@[66; 67)
-              IDENT@[66; 67) "D"
+              PATH_SEGMENT@[66; 67)
-              R_BRACK@[67; 68) "]"
+                NAME_REF@[66; 67)
+                  IDENT@[66; 67) "D"
+            R_BRACK@[67; 68) "]"
          WHITESPACE@[68; 69) " "
          RETURN_EXPR@[69; 78)
            RETURN_KW@[69; 75) "return"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt b/crates/ra_syntax/test_data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt
index c201196ec..21f49690a 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt
@@ -20,10 +20,12 @@ SOURCE_FILE@[0; 47)
              TRY_EXPR@[17; 29)
                ATTR@[17; 21)
                  POUND@[17; 18) "#"
-                  TOKEN_TREE@[18; 21)
+                  L_BRACK@[18; 19) "["
-                    L_BRACK@[18; 19) "["
+                  PATH@[19; 20)
-                    IDENT@[19; 20) "A"
+                    PATH_SEGMENT@[19; 20)
-                    R_BRACK@[20; 21) "]"
+                      NAME_REF@[19; 20)
+                        IDENT@[19; 20) "A"
+                  R_BRACK@[20; 21) "]"
                WHITESPACE@[21; 22) " "
                MACRO_CALL@[22; 28)
                  PATH@[22; 25)
@@ -41,10 +43,12 @@ SOURCE_FILE@[0; 47)
        REF_EXPR@[36; 44)
          ATTR@[36; 40)
            POUND@[36; 37) "#"
-            TOKEN_TREE@[37; 40)
+            L_BRACK@[37; 38) "["
-              L_BRACK@[37; 38) "["
+            PATH@[38; 39)
-              IDENT@[38; 39) "B"
+              PATH_SEGMENT@[38; 39)
-              R_BRACK@[39; 40) "]"
+                NAME_REF@[38; 39)
+                  IDENT@[38; 39) "B"
+            R_BRACK@[39; 40) "]"
          WHITESPACE@[40; 41) " "
          AMP@[41; 42) "&"
          TUPLE_EXPR@[42; 44)
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0135_first_array_member_attributes.txt b/crates/ra_syntax/test_data/parser/inline/ok/0135_first_array_member_attributes.txt
index eac4f6f30..8f2e91bdf 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0135_first_array_member_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0135_first_array_member_attributes.txt
@@ -29,14 +29,16 @@ SOURCE_FILE@[0; 56)
        WHITESPACE@[24; 28) "\n   "
        ATTR@[28; 40)
          POUND@[28; 29) "#"
-          TOKEN_TREE@[29; 40)
+          L_BRACK@[29; 30) "["
-            L_BRACK@[29; 30) "["
+          PATH@[30; 33)
-            IDENT@[30; 33) "cfg"
+            PATH_SEGMENT@[30; 33)
-            TOKEN_TREE@[33; 39)
+              NAME_REF@[30; 33)
-              L_PAREN@[33; 34) "("
+                IDENT@[30; 33) "cfg"
-              IDENT@[34; 38) "test"
+          TOKEN_TREE@[33; 39)
-              R_PAREN@[38; 39) ")"
+            L_PAREN@[33; 34) "("
-            R_BRACK@[39; 40) "]"
+            IDENT@[34; 38) "test"
+            R_PAREN@[38; 39) ")"
+          R_BRACK@[39; 40) "]"
        WHITESPACE@[40; 44) "\n   "
        LITERAL@[44; 45)
          INT_NUMBER@[44; 45) "1"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0136_subsequent_array_member_attributes.txt b/crates/ra_syntax/test_data/parser/inline/ok/0136_subsequent_array_member_attributes.txt
index 6fa1b42d9..41914eb8e 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0136_subsequent_array_member_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0136_subsequent_array_member_attributes.txt
@@ -33,14 +33,16 @@ SOURCE_FILE@[0; 56)
        WHITESPACE@[30; 34) "\n   "
        ATTR@[34; 46)
          POUND@[34; 35) "#"
-          TOKEN_TREE@[35; 46)
+          L_BRACK@[35; 36) "["
-            L_BRACK@[35; 36) "["
+          PATH@[36; 39)
-            IDENT@[36; 39) "cfg"
+            PATH_SEGMENT@[36; 39)
-            TOKEN_TREE@[39; 45)
+              NAME_REF@[36; 39)
-              L_PAREN@[39; 40) "("
+                IDENT@[36; 39) "cfg"
-              IDENT@[40; 44) "test"
+          TOKEN_TREE@[39; 45)
-              R_PAREN@[44; 45) ")"
+            L_PAREN@[39; 40) "("
-            R_BRACK@[45; 46) "]"
+            IDENT@[40; 44) "test"
+            R_PAREN@[44; 45) ")"
+          R_BRACK@[45; 46) "]"
        WHITESPACE@[46; 50) "\n   "
        LITERAL@[50; 51)
          INT_NUMBER@[50; 51) "2"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0138_self_param_outer_attr.txt b/crates/ra_syntax/test_data/parser/inline/ok/0138_self_param_outer_attr.txt
index 708fa4773..e627b9746 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0138_self_param_outer_attr.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0138_self_param_outer_attr.txt
@@ -8,10 +8,12 @@ SOURCE_FILE@[0; 26)
      L_PAREN@[4; 5) "("
      ATTR@[5; 16)
        POUND@[5; 6) "#"
-        TOKEN_TREE@[6; 16)
+        L_BRACK@[6; 7) "["
-          L_BRACK@[6; 7) "["
+        PATH@[7; 15)
-          IDENT@[7; 15) "must_use"
+          PATH_SEGMENT@[7; 15)
-          R_BRACK@[15; 16) "]"
+            NAME_REF@[7; 15)
+              IDENT@[7; 15) "must_use"
+        R_BRACK@[15; 16) "]"
      WHITESPACE@[16; 17) " "
      SELF_PARAM@[17; 21)
        SELF_KW@[17; 21) "self"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0139_param_outer_arg.txt b/crates/ra_syntax/test_data/parser/inline/ok/0139_param_outer_arg.txt
index 9c0a0d20b..cf202c94b 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0139_param_outer_arg.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0139_param_outer_arg.txt
@@ -8,10 +8,12 @@ SOURCE_FILE@[0; 28)
      L_PAREN@[4; 5) "("
      ATTR@[5; 13)
        POUND@[5; 6) "#"
-        TOKEN_TREE@[6; 13)
+        L_BRACK@[6; 7) "["
-          L_BRACK@[6; 7) "["
+        PATH@[7; 12)
-          IDENT@[7; 12) "attr1"
+          PATH_SEGMENT@[7; 12)
-          R_BRACK@[12; 13) "]"
+            NAME_REF@[7; 12)
+              IDENT@[7; 12) "attr1"
+        R_BRACK@[12; 13) "]"
      WHITESPACE@[13; 14) " "
      PARAM@[14; 23)
        BIND_PAT@[14; 17)
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.rs b/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.rs
new file mode 100644
index 000000000..a06dec1fa
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.rs
@@ -0,0 +1,3 @@
+fn foo() {
+    let _ = &1 as *const i32;
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.txt b/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.txt
new file mode 100644
index 000000000..9e3767fb7
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0146_as_precedence.txt
@@ -0,0 +1,43 @@
+SOURCE_FILE@[0; 43)
+  FN_DEF@[0; 42)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 42)
+      BLOCK@[9; 42)
+        L_CURLY@[9; 10) "{"
+        WHITESPACE@[10; 15) "\n    "
+        LET_STMT@[15; 40)
+          LET_KW@[15; 18) "let"
+          WHITESPACE@[18; 19) " "
+          PLACEHOLDER_PAT@[19; 20)
+            UNDERSCORE@[19; 20) "_"
+          WHITESPACE@[20; 21) " "
+          EQ@[21; 22) "="
+          WHITESPACE@[22; 23) " "
+          CAST_EXPR@[23; 39)
+            REF_EXPR@[23; 25)
+              AMP@[23; 24) "&"
+              LITERAL@[24; 25)
+                INT_NUMBER@[24; 25) "1"
+            WHITESPACE@[25; 26) " "
+            AS_KW@[26; 28) "as"
+            WHITESPACE@[28; 29) " "
+            POINTER_TYPE@[29; 39)
+              STAR@[29; 30) "*"
+              CONST_KW@[30; 35) "const"
+              WHITESPACE@[35; 36) " "
+              PATH_TYPE@[36; 39)
+                PATH@[36; 39)
+                  PATH_SEGMENT@[36; 39)
+                    NAME_REF@[36; 39)
+                      IDENT@[36; 39) "i32"
+          SEMI@[39; 40) ";"
+        WHITESPACE@[40; 41) "\n"
+        R_CURLY@[41; 42) "}"
+  WHITESPACE@[42; 43) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0006_inner_attributes.txt b/crates/ra_syntax/test_data/parser/ok/0006_inner_attributes.txt
index d8cabc9af..d72b72561 100644
--- a/crates/ra_syntax/test_data/parser/ok/0006_inner_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0006_inner_attributes.txt
@@ -2,163 +2,183 @@ SOURCE_FILE@[0; 236)
  ATTR@[0; 8)
    POUND@[0; 1) "#"
    EXCL@[1; 2) "!"
-    TOKEN_TREE@[2; 8)
+    L_BRACK@[2; 3) "["
-      L_BRACK@[2; 3) "["
+    PATH@[3; 7)
-      IDENT@[3; 7) "attr"
+      PATH_SEGMENT@[3; 7)
-      R_BRACK@[7; 8) "]"
+        NAME_REF@[3; 7)
+          IDENT@[3; 7) "attr"
+    R_BRACK@[7; 8) "]"
  WHITESPACE@[8; 9) "\n"
  ATTR@[9; 23)
    POUND@[9; 10) "#"
    EXCL@[10; 11) "!"
-    TOKEN_TREE@[11; 23)
+    L_BRACK@[11; 12) "["
-      L_BRACK@[11; 12) "["
+    PATH@[12; 16)
-      IDENT@[12; 16) "attr"
+      PATH_SEGMENT@[12; 16)
-      TOKEN_TREE@[16; 22)
+        NAME_REF@[12; 16)
-        L_PAREN@[16; 17) "("
+          IDENT@[12; 16) "attr"
-        TRUE_KW@[17; 21) "true"
+    TOKEN_TREE@[16; 22)
-        R_PAREN@[21; 22) ")"
+      L_PAREN@[16; 17) "("
-      R_BRACK@[22; 23) "]"
+      TRUE_KW@[17; 21) "true"
+      R_PAREN@[21; 22) ")"
+    R_BRACK@[22; 23) "]"
  WHITESPACE@[23; 24) "\n"
  ATTR@[24; 39)
    POUND@[24; 25) "#"
    EXCL@[25; 26) "!"
-    TOKEN_TREE@[26; 39)
+    L_BRACK@[26; 27) "["
-      L_BRACK@[26; 27) "["
+    PATH@[27; 31)
-      IDENT@[27; 31) "attr"
+      PATH_SEGMENT@[27; 31)
-      TOKEN_TREE@[31; 38)
+        NAME_REF@[27; 31)
-        L_PAREN@[31; 32) "("
+          IDENT@[27; 31) "attr"
-        IDENT@[32; 37) "ident"
+    TOKEN_TREE@[31; 38)
-        R_PAREN@[37; 38) ")"
+      L_PAREN@[31; 32) "("
-      R_BRACK@[38; 39) "]"
+      IDENT@[32; 37) "ident"
+      R_PAREN@[37; 38) ")"
+    R_BRACK@[38; 39) "]"
  WHITESPACE@[39; 40) "\n"
  ATTR@[40; 116)
    POUND@[40; 41) "#"
    EXCL@[41; 42) "!"
-    TOKEN_TREE@[42; 116)
+    L_BRACK@[42; 43) "["
-      L_BRACK@[42; 43) "["
+    PATH@[43; 47)
-      IDENT@[43; 47) "attr"
+      PATH_SEGMENT@[43; 47)
-      TOKEN_TREE@[47; 115)
+        NAME_REF@[43; 47)
-        L_PAREN@[47; 48) "("
+          IDENT@[43; 47) "attr"
-        IDENT@[48; 53) "ident"
+    TOKEN_TREE@[47; 115)
-        COMMA@[53; 54) ","
+      L_PAREN@[47; 48) "("
-        WHITESPACE@[54; 55) " "
+      IDENT@[48; 53) "ident"
-        INT_NUMBER@[55; 58) "100"
+      COMMA@[53; 54) ","
-        COMMA@[58; 59) ","
+      WHITESPACE@[54; 55) " "
-        WHITESPACE@[59; 60) " "
+      INT_NUMBER@[55; 58) "100"
-        TRUE_KW@[60; 64) "true"
+      COMMA@[58; 59) ","
-        COMMA@[64; 65) ","
+      WHITESPACE@[59; 60) " "
-        WHITESPACE@[65; 66) " "
+      TRUE_KW@[60; 64) "true"
-        STRING@[66; 72) "\"true\""
+      COMMA@[64; 65) ","
-        COMMA@[72; 73) ","
+      WHITESPACE@[65; 66) " "
-        WHITESPACE@[73; 74) " "
+      STRING@[66; 72) "\"true\""
-        IDENT@[74; 79) "ident"
+      COMMA@[72; 73) ","
-        WHITESPACE@[79; 80) " "
+      WHITESPACE@[73; 74) " "
-        EQ@[80; 81) "="
+      IDENT@[74; 79) "ident"
-        WHITESPACE@[81; 82) " "
+      WHITESPACE@[79; 80) " "
-        INT_NUMBER@[82; 85) "100"
+      EQ@[80; 81) "="
-        COMMA@[85; 86) ","
+      WHITESPACE@[81; 82) " "
-        WHITESPACE@[86; 87) " "
+      INT_NUMBER@[82; 85) "100"
-        IDENT@[87; 92) "ident"
+      COMMA@[85; 86) ","
-        WHITESPACE@[92; 93) " "
+      WHITESPACE@[86; 87) " "
-        EQ@[93; 94) "="
+      IDENT@[87; 92) "ident"
-        WHITESPACE@[94; 95) " "
+      WHITESPACE@[92; 93) " "
-        STRING@[95; 102) "\"hello\""
+      EQ@[93; 94) "="
-        COMMA@[102; 103) ","
+      WHITESPACE@[94; 95) " "
-        WHITESPACE@[103; 104) " "
+      STRING@[95; 102) "\"hello\""
-        IDENT@[104; 109) "ident"
+      COMMA@[102; 103) ","
-        TOKEN_TREE@[109; 114)
+      WHITESPACE@[103; 104) " "
-          L_PAREN@[109; 110) "("
+      IDENT@[104; 109) "ident"
-          INT_NUMBER@[110; 113) "100"
+      TOKEN_TREE@[109; 114)
-          R_PAREN@[113; 114) ")"
+        L_PAREN@[109; 110) "("
-        R_PAREN@[114; 115) ")"
+        INT_NUMBER@[110; 113) "100"
-      R_BRACK@[115; 116) "]"
+        R_PAREN@[113; 114) ")"
+      R_PAREN@[114; 115) ")"
+    R_BRACK@[115; 116) "]"
  WHITESPACE@[116; 117) "\n"
  ATTR@[117; 130)
    POUND@[117; 118) "#"
    EXCL@[118; 119) "!"
-    TOKEN_TREE@[119; 130)
+    L_BRACK@[119; 120) "["
-      L_BRACK@[119; 120) "["
+    PATH@[120; 124)
-      IDENT@[120; 124) "attr"
+      PATH_SEGMENT@[120; 124)
-      TOKEN_TREE@[124; 129)
+        NAME_REF@[120; 124)
-        L_PAREN@[124; 125) "("
+          IDENT@[120; 124) "attr"
-        INT_NUMBER@[125; 128) "100"
+    TOKEN_TREE@[124; 129)
-        R_PAREN@[128; 129) ")"
+      L_PAREN@[124; 125) "("
-      R_BRACK@[129; 130) "]"
+      INT_NUMBER@[125; 128) "100"
+      R_PAREN@[128; 129) ")"
+    R_BRACK@[129; 130) "]"
  WHITESPACE@[130; 131) "\n"
  ATTR@[131; 155)
    POUND@[131; 132) "#"
    EXCL@[132; 133) "!"
-    TOKEN_TREE@[133; 155)
+    L_BRACK@[133; 134) "["
-      L_BRACK@[133; 134) "["
+    PATH@[134; 138)
-      IDENT@[134; 138) "attr"
+      PATH_SEGMENT@[134; 138)
-      TOKEN_TREE@[138; 154)
+        NAME_REF@[134; 138)
-        L_PAREN@[138; 139) "("
+          IDENT@[134; 138) "attr"
-        IDENT@[139; 146) "enabled"
+    TOKEN_TREE@[138; 154)
-        WHITESPACE@[146; 147) " "
+      L_PAREN@[138; 139) "("
-        EQ@[147; 148) "="
+      IDENT@[139; 146) "enabled"
-        WHITESPACE@[148; 149) " "
+      WHITESPACE@[146; 147) " "
-        TRUE_KW@[149; 153) "true"
+      EQ@[147; 148) "="
-        R_PAREN@[153; 154) ")"
+      WHITESPACE@[148; 149) " "
-      R_BRACK@[154; 155) "]"
+      TRUE_KW@[149; 153) "true"
+      R_PAREN@[153; 154) ")"
+    R_BRACK@[154; 155) "]"
  WHITESPACE@[155; 156) "\n"
  ATTR@[156; 173)
    POUND@[156; 157) "#"
    EXCL@[157; 158) "!"
-    TOKEN_TREE@[158; 173)
+    L_BRACK@[158; 159) "["
-      L_BRACK@[158; 159) "["
+    PATH@[159; 166)
-      IDENT@[159; 166) "enabled"
+      PATH_SEGMENT@[159; 166)
-      TOKEN_TREE@[166; 172)
+        NAME_REF@[159; 166)
-        L_PAREN@[166; 167) "("
+          IDENT@[159; 166) "enabled"
-        TRUE_KW@[167; 171) "true"
+    TOKEN_TREE@[166; 172)
-        R_PAREN@[171; 172) ")"
+      L_PAREN@[166; 167) "("
-      R_BRACK@[172; 173) "]"
+      TRUE_KW@[167; 171) "true"
+      R_PAREN@[171; 172) ")"
+    R_BRACK@[172; 173) "]"
  WHITESPACE@[173; 174) "\n"
  ATTR@[174; 191)
    POUND@[174; 175) "#"
    EXCL@[175; 176) "!"
-    TOKEN_TREE@[176; 191)
+    L_BRACK@[176; 177) "["
-      L_BRACK@[176; 177) "["
+    PATH@[177; 181)
-      IDENT@[177; 181) "attr"
+      PATH_SEGMENT@[177; 181)
-      TOKEN_TREE@[181; 190)
+        NAME_REF@[177; 181)
-        L_PAREN@[181; 182) "("
+          IDENT@[177; 181) "attr"
-        STRING@[182; 189) "\"hello\""
+    TOKEN_TREE@[181; 190)
-        R_PAREN@[189; 190) ")"
+      L_PAREN@[181; 182) "("
-      R_BRACK@[190; 191) "]"
+      STRING@[182; 189) "\"hello\""
+      R_PAREN@[189; 190) ")"
+    R_BRACK@[190; 191) "]"
  WHITESPACE@[191; 192) "\n"
  ATTR@[192; 214)
    POUND@[192; 193) "#"
    EXCL@[193; 194) "!"
-    TOKEN_TREE@[194; 214)
+    L_BRACK@[194; 195) "["
-      L_BRACK@[194; 195) "["
+    PATH@[195; 199)
-      IDENT@[195; 199) "repr"
+      PATH_SEGMENT@[195; 199)
-      TOKEN_TREE@[199; 213)
+        NAME_REF@[195; 199)
-        L_PAREN@[199; 200) "("
+          IDENT@[195; 199) "repr"
-        IDENT@[200; 201) "C"
+    TOKEN_TREE@[199; 213)
-        COMMA@[201; 202) ","
+      L_PAREN@[199; 200) "("
-        WHITESPACE@[202; 203) " "
+      IDENT@[200; 201) "C"
-        IDENT@[203; 208) "align"
+      COMMA@[201; 202) ","
-        WHITESPACE@[208; 209) " "
+      WHITESPACE@[202; 203) " "
-        EQ@[209; 210) "="
+      IDENT@[203; 208) "align"
-        WHITESPACE@[210; 211) " "
+      WHITESPACE@[208; 209) " "
-        INT_NUMBER@[211; 212) "4"
+      EQ@[209; 210) "="
-        R_PAREN@[212; 213) ")"
+      WHITESPACE@[210; 211) " "
-      R_BRACK@[213; 214) "]"
+      INT_NUMBER@[211; 212) "4"
+      R_PAREN@[212; 213) ")"
+    R_BRACK@[213; 214) "]"
  WHITESPACE@[214; 215) "\n"
  ATTR@[215; 236)
    POUND@[215; 216) "#"
    EXCL@[216; 217) "!"
-    TOKEN_TREE@[217; 236)
+    L_BRACK@[217; 218) "["
-      L_BRACK@[217; 218) "["
+    PATH@[218; 222)
-      IDENT@[218; 222) "repr"
+      PATH_SEGMENT@[218; 222)
-      TOKEN_TREE@[222; 235)
+        NAME_REF@[218; 222)
-        L_PAREN@[222; 223) "("
+          IDENT@[218; 222) "repr"
-        IDENT@[223; 224) "C"
+    TOKEN_TREE@[222; 235)
-        COMMA@[224; 225) ","
+      L_PAREN@[222; 223) "("
-        WHITESPACE@[225; 226) " "
+      IDENT@[223; 224) "C"
-        IDENT@[226; 231) "align"
+      COMMA@[224; 225) ","
-        TOKEN_TREE@[231; 234)
+      WHITESPACE@[225; 226) " "
-          L_PAREN@[231; 232) "("
+      IDENT@[226; 231) "align"
-          INT_NUMBER@[232; 233) "4"
+      TOKEN_TREE@[231; 234)
-          R_PAREN@[233; 234) ")"
+        L_PAREN@[231; 232) "("
-        R_PAREN@[234; 235) ")"
+        INT_NUMBER@[232; 233) "4"
-      R_BRACK@[235; 236) "]"
+        R_PAREN@[233; 234) ")"
+      R_PAREN@[234; 235) ")"
+    R_BRACK@[235; 236) "]"
diff --git a/crates/ra_syntax/test_data/parser/ok/0008_mod_item.txt b/crates/ra_syntax/test_data/parser/ok/0008_mod_item.txt
index 35465632d..061019a73 100644
--- a/crates/ra_syntax/test_data/parser/ok/0008_mod_item.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0008_mod_item.txt
@@ -65,10 +65,12 @@ SOURCE_FILE@[0; 118)
      ATTR@[79; 87)
        POUND@[79; 80) "#"
        EXCL@[80; 81) "!"
-        TOKEN_TREE@[81; 87)
+        L_BRACK@[81; 82) "["
-          L_BRACK@[81; 82) "["
+        PATH@[82; 86)
-          IDENT@[82; 86) "attr"
+          PATH_SEGMENT@[82; 86)
-          R_BRACK@[86; 87) "]"
+            NAME_REF@[82; 86)
+              IDENT@[82; 86) "attr"
+        R_BRACK@[86; 87) "]"
      WHITESPACE@[87; 92) "\n    "
      MODULE@[92; 98)
        MOD_KW@[92; 95) "mod"
diff --git a/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.rs b/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.rs
index 8b80c0d90..3d2e01d5c 100644
--- a/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.rs
+++ b/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.rs
@@ -1,3 +1,6 @@
 #[cfg(test)]
 #[ignore]
 fn foo() {}
+#[path = "a.rs"]
+mod b;
diff --git a/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.txt b/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.txt
index a845c5c24..f7aa8afe4 100644
--- a/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0011_outer_attribute.txt
@@ -1,22 +1,26 @@
-SOURCE_FILE@[0; 35)
+SOURCE_FILE@[0; 60)
  FN_DEF@[0; 34)
    ATTR@[0; 12)
      POUND@[0; 1) "#"
-      TOKEN_TREE@[1; 12)
+      L_BRACK@[1; 2) "["
-        L_BRACK@[1; 2) "["
+      PATH@[2; 5)
-        IDENT@[2; 5) "cfg"
+        PATH_SEGMENT@[2; 5)
-        TOKEN_TREE@[5; 11)
+          NAME_REF@[2; 5)
-          L_PAREN@[5; 6) "("
+            IDENT@[2; 5) "cfg"
-          IDENT@[6; 10) "test"
+      TOKEN_TREE@[5; 11)
-          R_PAREN@[10; 11) ")"
+        L_PAREN@[5; 6) "("
-        R_BRACK@[11; 12) "]"
+        IDENT@[6; 10) "test"
+        R_PAREN@[10; 11) ")"
+      R_BRACK@[11; 12) "]"
    WHITESPACE@[12; 13) "\n"
    ATTR@[13; 22)
      POUND@[13; 14) "#"
-      TOKEN_TREE@[14; 22)
+      L_BRACK@[14; 15) "["
-        L_BRACK@[14; 15) "["
+      PATH@[15; 21)
-        IDENT@[15; 21) "ignore"
+        PATH_SEGMENT@[15; 21)
-        R_BRACK@[21; 22) "]"
+          NAME_REF@[15; 21)
+            IDENT@[15; 21) "ignore"
+      R_BRACK@[21; 22) "]"
    WHITESPACE@[22; 23) "\n"
    FN_KW@[23; 25) "fn"
    WHITESPACE@[25; 26) " "
@@ -30,4 +34,25 @@ SOURCE_FILE@[0; 35)
      BLOCK@[32; 34)
        L_CURLY@[32; 33) "{"
        R_CURLY@[33; 34) "}"
-  WHITESPACE@[34; 35) "\n"
+  WHITESPACE@[34; 36) "\n\n"
+  MODULE@[36; 59)
+    ATTR@[36; 52)
+      POUND@[36; 37) "#"
+      L_BRACK@[37; 38) "["
+      PATH@[38; 42)
+        PATH_SEGMENT@[38; 42)
+          NAME_REF@[38; 42)
+            IDENT@[38; 42) "path"
+      WHITESPACE@[42; 43) " "
+      EQ@[43; 44) "="
+      WHITESPACE@[44; 45) " "
+      LITERAL@[45; 51)
+        STRING@[45; 51) "\"a.rs\""
+      R_BRACK@[51; 52) "]"
+    WHITESPACE@[52; 53) "\n"
+    MOD_KW@[53; 56) "mod"
+    WHITESPACE@[56; 57) " "
+    NAME@[57; 58)
+      IDENT@[57; 58) "b"
+    SEMI@[58; 59) ";"
+  WHITESPACE@[59; 60) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0017_attr_trailing_comma.txt b/crates/ra_syntax/test_data/parser/ok/0017_attr_trailing_comma.txt
index a1084b221..1d65b0d6e 100644
--- a/crates/ra_syntax/test_data/parser/ok/0017_attr_trailing_comma.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0017_attr_trailing_comma.txt
@@ -2,15 +2,17 @@ SOURCE_FILE@[0; 23)
  FN_DEF@[0; 22)
    ATTR@[0; 10)
      POUND@[0; 1) "#"
-      TOKEN_TREE@[1; 10)
+      L_BRACK@[1; 2) "["
-        L_BRACK@[1; 2) "["
+      PATH@[2; 5)
-        IDENT@[2; 5) "foo"
+        PATH_SEGMENT@[2; 5)
-        TOKEN_TREE@[5; 9)
+          NAME_REF@[2; 5)
-          L_PAREN@[5; 6) "("
+            IDENT@[2; 5) "foo"
-          IDENT@[6; 7) "a"
+      TOKEN_TREE@[5; 9)
-          COMMA@[7; 8) ","
+        L_PAREN@[5; 6) "("
-          R_PAREN@[8; 9) ")"
+        IDENT@[6; 7) "a"
-        R_BRACK@[9; 10) "]"
+        COMMA@[7; 8) ","
+        R_PAREN@[8; 9) ")"
+      R_BRACK@[9; 10) "]"
    WHITESPACE@[10; 11) "\n"
    FN_KW@[11; 13) "fn"
    WHITESPACE@[13; 14) " "
diff --git a/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt b/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
index 3326ab2ae..3260cc589 100644
--- a/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0035_weird_exprs.txt
@@ -10,62 +10,73 @@ SOURCE_FILE@[0; 3813)
  ATTR@[271; 302)
    POUND@[271; 272) "#"
    EXCL@[272; 273) "!"
-    TOKEN_TREE@[273; 302)
+    L_BRACK@[273; 274) "["
-      L_BRACK@[273; 274) "["
+    PATH@[274; 279)
-      IDENT@[274; 279) "allow"
+      PATH_SEGMENT@[274; 279)
-      TOKEN_TREE@[279; 301)
+        NAME_REF@[274; 279)
-        L_PAREN@[279; 280) "("
+          IDENT@[274; 279) "allow"
-        IDENT@[280; 300) "non_camel_case_types"
+    TOKEN_TREE@[279; 301)
-        R_PAREN@[300; 301) ")"
+      L_PAREN@[279; 280) "("
-      R_BRACK@[301; 302) "]"
+      IDENT@[280; 300) "non_camel_case_types"
+      R_PAREN@[300; 301) ")"
+    R_BRACK@[301; 302) "]"
  WHITESPACE@[302; 303) "\n"
  ATTR@[303; 323)
    POUND@[303; 304) "#"
    EXCL@[304; 305) "!"
-    TOKEN_TREE@[305; 323)
+    L_BRACK@[305; 306) "["
-      L_BRACK@[305; 306) "["
+    PATH@[306; 311)
-      IDENT@[306; 311) "allow"
+      PATH_SEGMENT@[306; 311)
-      TOKEN_TREE@[311; 322)
+        NAME_REF@[306; 311)
-        L_PAREN@[311; 312) "("
+          IDENT@[306; 311) "allow"
-        IDENT@[312; 321) "dead_code"
+    TOKEN_TREE@[311; 322)
-        R_PAREN@[321; 322) ")"
+      L_PAREN@[311; 312) "("
-      R_BRACK@[322; 323) "]"
+      IDENT@[312; 321) "dead_code"
+      R_PAREN@[321; 322) ")"
+    R_BRACK@[322; 323) "]"
  WHITESPACE@[323; 324) "\n"
  ATTR@[324; 351)
    POUND@[324; 325) "#"
    EXCL@[325; 326) "!"
-    TOKEN_TREE@[326; 351)
+    L_BRACK@[326; 327) "["
-      L_BRACK@[326; 327) "["
+    PATH@[327; 332)
-      IDENT@[327; 332) "allow"
+      PATH_SEGMENT@[327; 332)
-      TOKEN_TREE@[332; 350)
+        NAME_REF@[327; 332)
-        L_PAREN@[332; 333) "("
+          IDENT@[327; 332) "allow"
-        IDENT@[333; 349) "unreachable_code"
+    TOKEN_TREE@[332; 350)
-        R_PAREN@[349; 350) ")"
+      L_PAREN@[332; 333) "("
-      R_BRACK@[350; 351) "]"
+      IDENT@[333; 349) "unreachable_code"
+      R_PAREN@[349; 350) ")"
+    R_BRACK@[350; 351) "]"
  WHITESPACE@[351; 352) "\n"
  ATTR@[352; 376)
    POUND@[352; 353) "#"
    EXCL@[353; 354) "!"
-    TOKEN_TREE@[354; 376)
+    L_BRACK@[354; 355) "["
-      L_BRACK@[354; 355) "["
+    PATH@[355; 360)
-      IDENT@[355; 360) "allow"
+      PATH_SEGMENT@[355; 360)
-      TOKEN_TREE@[360; 375)
+        NAME_REF@[355; 360)
-        L_PAREN@[360; 361) "("
+          IDENT@[355; 360) "allow"
-        IDENT@[361; 374) "unused_parens"
+    TOKEN_TREE@[360; 375)
-        R_PAREN@[374; 375) ")"
+      L_PAREN@[360; 361) "("
-      R_BRACK@[375; 376) "]"
+      IDENT@[361; 374) "unused_parens"
+      R_PAREN@[374; 375) ")"
+    R_BRACK@[375; 376) "]"
  WHITESPACE@[376; 378) "\n\n"
  ATTR@[378; 405)
    POUND@[378; 379) "#"
    EXCL@[379; 380) "!"
-    TOKEN_TREE@[380; 405)
+    L_BRACK@[380; 381) "["
-      L_BRACK@[380; 381) "["
+    PATH@[381; 396)
-      IDENT@[381; 396) "recursion_limit"
+      PATH_SEGMENT@[381; 396)
-      WHITESPACE@[396; 397) " "
+        NAME_REF@[381; 396)
-      EQ@[397; 398) "="
+          IDENT@[381; 396) "recursion_limit"
-      WHITESPACE@[398; 399) " "
+    WHITESPACE@[396; 397) " "
+    EQ@[397; 398) "="
+    WHITESPACE@[398; 399) " "
+    LITERAL@[399; 404)
      STRING@[399; 404) "\"128\""
-      R_BRACK@[404; 405) "]"
+    R_BRACK@[404; 405) "]"
  WHITESPACE@[405; 407) "\n\n"
  USE_ITEM@[407; 427)
    USE_KW@[407; 410) "use"
diff --git a/crates/ra_syntax/test_data/parser/ok/0044_let_attrs.txt b/crates/ra_syntax/test_data/parser/ok/0044_let_attrs.txt
index 7dabe535f..bfc793dc1 100644
--- a/crates/ra_syntax/test_data/parser/ok/0044_let_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0044_let_attrs.txt
@@ -17,18 +17,20 @@ SOURCE_FILE@[0; 166)
        LET_STMT@[77; 163)
          ATTR@[77; 106)
            POUND@[77; 78) "#"
-            TOKEN_TREE@[78; 106)
+            L_BRACK@[78; 79) "["
-              L_BRACK@[78; 79) "["
+            PATH@[79; 82)
-              IDENT@[79; 82) "cfg"
+              PATH_SEGMENT@[79; 82)
-              TOKEN_TREE@[82; 105)
+                NAME_REF@[79; 82)
-                L_PAREN@[82; 83) "("
+                  IDENT@[79; 82) "cfg"
-                IDENT@[83; 90) "feature"
+            TOKEN_TREE@[82; 105)
-                WHITESPACE@[90; 91) " "
+              L_PAREN@[82; 83) "("
-                EQ@[91; 92) "="
+              IDENT@[83; 90) "feature"
-                WHITESPACE@[92; 93) " "
+              WHITESPACE@[90; 91) " "
-                STRING@[93; 104) "\"backtrace\""
+              EQ@[91; 92) "="
-                R_PAREN@[104; 105) ")"
+              WHITESPACE@[92; 93) " "
-              R_BRACK@[105; 106) "]"
+              STRING@[93; 104) "\"backtrace\""
+              R_PAREN@[104; 105) ")"
+            R_BRACK@[105; 106) "]"
          WHITESPACE@[106; 111) "\n    "
          LET_KW@[111; 114) "let"
          WHITESPACE@[114; 115) " "
diff --git a/crates/ra_syntax/test_data/parser/ok/0045_block_inner_attrs.txt b/crates/ra_syntax/test_data/parser/ok/0045_block_inner_attrs.txt
index e8be8203b..3d9aab500 100644
--- a/crates/ra_syntax/test_data/parser/ok/0045_block_inner_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0045_block_inner_attrs.txt
@@ -15,14 +15,16 @@ SOURCE_FILE@[0; 686)
        ATTR@[17; 57)
          POUND@[17; 18) "#"
          EXCL@[18; 19) "!"
-          TOKEN_TREE@[19; 57)
+          L_BRACK@[19; 20) "["
-            L_BRACK@[19; 20) "["
+          PATH@[20; 23)
-            IDENT@[20; 23) "doc"
+            PATH_SEGMENT@[20; 23)
-            TOKEN_TREE@[23; 56)
+              NAME_REF@[20; 23)
-              L_PAREN@[23; 24) "("
+                IDENT@[20; 23) "doc"
-              STRING@[24; 55) "\"Inner attributes all ..."
+          TOKEN_TREE@[23; 56)
-              R_PAREN@[55; 56) ")"
+            L_PAREN@[23; 24) "("
-            R_BRACK@[56; 57) "]"
+            STRING@[24; 55) "\"Inner attributes all ..."
+            R_PAREN@[55; 56) ")"
+          R_BRACK@[56; 57) "]"
        WHITESPACE@[57; 62) "\n    "
        COMMENT@[62; 97) "//! As are ModuleDoc  ..."
        WHITESPACE@[97; 102) "\n    "
@@ -34,26 +36,30 @@ SOURCE_FILE@[0; 686)
              ATTR@[112; 180)
                POUND@[112; 113) "#"
                EXCL@[113; 114) "!"
-                TOKEN_TREE@[114; 180)
+                L_BRACK@[114; 115) "["
-                  L_BRACK@[114; 115) "["
+                PATH@[115; 118)
-                  IDENT@[115; 118) "doc"
+                  PATH_SEGMENT@[115; 118)
-                  TOKEN_TREE@[118; 179)
+                    NAME_REF@[115; 118)
-                    L_PAREN@[118; 119) "("
+                      IDENT@[115; 118) "doc"
-                    STRING@[119; 178) "\"Inner attributes are ..."
+                TOKEN_TREE@[118; 179)
-                    R_PAREN@[178; 179) ")"
+                  L_PAREN@[118; 119) "("
-                  R_BRACK@[179; 180) "]"
+                  STRING@[119; 178) "\"Inner attributes are ..."
+                  R_PAREN@[178; 179) ")"
+                R_BRACK@[179; 180) "]"
              WHITESPACE@[180; 189) "\n        "
              ATTR@[189; 244)
                POUND@[189; 190) "#"
                EXCL@[190; 191) "!"
-                TOKEN_TREE@[191; 244)
+                L_BRACK@[191; 192) "["
-                  L_BRACK@[191; 192) "["
+                PATH@[192; 195)
-                  IDENT@[192; 195) "doc"
+                  PATH_SEGMENT@[192; 195)
-                  TOKEN_TREE@[195; 243)
+                    NAME_REF@[192; 195)
-                    L_PAREN@[195; 196) "("
+                      IDENT@[192; 195) "doc"
-                    STRING@[196; 242) "\"Being validated is n ..."
+                TOKEN_TREE@[195; 243)
-                    R_PAREN@[242; 243) ")"
+                  L_PAREN@[195; 196) "("
-                  R_BRACK@[243; 244) "]"
+                  STRING@[196; 242) "\"Being validated is n ..."
+                  R_PAREN@[242; 243) ")"
+                R_BRACK@[243; 244) "]"
              WHITESPACE@[244; 253) "\n        "
              COMMENT@[253; 288) "//! As are ModuleDoc  ..."
              WHITESPACE@[288; 293) "\n    "
@@ -67,14 +73,16 @@ SOURCE_FILE@[0; 686)
            ATTR@[310; 409)
              POUND@[310; 311) "#"
              EXCL@[311; 312) "!"
-              TOKEN_TREE@[312; 409)
+              L_BRACK@[312; 313) "["
-                L_BRACK@[312; 313) "["
+              PATH@[313; 316)
-                IDENT@[313; 316) "doc"
+                PATH_SEGMENT@[313; 316)
-                TOKEN_TREE@[316; 408)
+                  NAME_REF@[313; 316)
-                  L_PAREN@[316; 317) "("
+                    IDENT@[313; 316) "doc"
-                  STRING@[317; 407) "\"Inner attributes are ..."
+              TOKEN_TREE@[316; 408)
-                  R_PAREN@[407; 408) ")"
+                L_PAREN@[316; 317) "("
-                R_BRACK@[408; 409) "]"
+                STRING@[317; 407) "\"Inner attributes are ..."
+                R_PAREN@[407; 408) ")"
+              R_BRACK@[408; 409) "]"
            WHITESPACE@[409; 418) "\n        "
            COMMENT@[418; 453) "//! As are ModuleDoc  ..."
            WHITESPACE@[453; 458) "\n    "
@@ -154,14 +162,16 @@ SOURCE_FILE@[0; 686)
            ATTR@[612; 639)
              POUND@[612; 613) "#"
              EXCL@[613; 614) "!"
-              TOKEN_TREE@[614; 639)
+              L_BRACK@[614; 615) "["
-                L_BRACK@[614; 615) "["
+              PATH@[615; 620)
-                IDENT@[615; 620) "allow"
+                PATH_SEGMENT@[615; 620)
-                TOKEN_TREE@[620; 638)
+                  NAME_REF@[615; 620)
-                  L_PAREN@[620; 621) "("
+                    IDENT@[615; 620) "allow"
-                  IDENT@[621; 637) "unused_variables"
+              TOKEN_TREE@[620; 638)
-                  R_PAREN@[637; 638) ")"
+                L_PAREN@[620; 621) "("
-                R_BRACK@[638; 639) "]"
+                IDENT@[621; 637) "unused_variables"
+                R_PAREN@[637; 638) ")"
+              R_BRACK@[638; 639) "]"
            WHITESPACE@[639; 640) " "
            COMMENT@[640; 677) "// this is  `inner_at ..."
            WHITESPACE@[677; 682) "\n    "
diff --git a/crates/ra_syntax/test_data/parser/ok/0046_extern_inner_attributes.txt b/crates/ra_syntax/test_data/parser/ok/0046_extern_inner_attributes.txt
index 4487a6e2e..8f192124b 100644
--- a/crates/ra_syntax/test_data/parser/ok/0046_extern_inner_attributes.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0046_extern_inner_attributes.txt
@@ -13,14 +13,16 @@ SOURCE_FILE@[0; 87)
      ATTR@[47; 84)
        POUND@[47; 48) "#"
        EXCL@[48; 49) "!"
-        TOKEN_TREE@[49; 84)
+        L_BRACK@[49; 50) "["
-          L_BRACK@[49; 50) "["
+        PATH@[50; 53)
-          IDENT@[50; 53) "doc"
+          PATH_SEGMENT@[50; 53)
-          TOKEN_TREE@[53; 83)
+            NAME_REF@[50; 53)
-            L_PAREN@[53; 54) "("
+              IDENT@[50; 53) "doc"
-            STRING@[54; 82) "\"This is also a doc c ..."
+        TOKEN_TREE@[53; 83)
-            R_PAREN@[82; 83) ")"
+          L_PAREN@[53; 54) "("
-          R_BRACK@[83; 84) "]"
+          STRING@[54; 82) "\"This is also a doc c ..."
+          R_PAREN@[82; 83) ")"
+        R_BRACK@[83; 84) "]"
      WHITESPACE@[84; 85) "\n"
      R_CURLY@[85; 86) "}"
  WHITESPACE@[86; 87) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt b/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
index e08fb4988..bfd47d2e1 100644
--- a/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0051_parameter_attrs.txt
@@ -8,17 +8,21 @@ SOURCE_FILE@[0; 519)
      L_PAREN@[5; 6) "("
      ATTR@[6; 14)
        POUND@[6; 7) "#"
-        TOKEN_TREE@[7; 14)
+        L_BRACK@[7; 8) "["
-          L_BRACK@[7; 8) "["
+        PATH@[8; 13)
-          IDENT@[8; 13) "attr1"
+          PATH_SEGMENT@[8; 13)
-          R_BRACK@[13; 14) "]"
+            NAME_REF@[8; 13)
+              IDENT@[8; 13) "attr1"
+        R_BRACK@[13; 14) "]"
      WHITESPACE@[14; 15) " "
      ATTR@[15; 23)
        POUND@[15; 16) "#"
-        TOKEN_TREE@[16; 23)
+        L_BRACK@[16; 17) "["
-          L_BRACK@[16; 17) "["
+        PATH@[17; 22)
-          IDENT@[17; 22) "attr2"
+          PATH_SEGMENT@[17; 22)
-          R_BRACK@[22; 23) "]"
+            NAME_REF@[17; 22)
+              IDENT@[17; 22) "attr2"
+        R_BRACK@[22; 23) "]"
      WHITESPACE@[23; 24) " "
      PARAM@[24; 33)
        BIND_PAT@[24; 27)
@@ -47,10 +51,12 @@ SOURCE_FILE@[0; 519)
      L_PAREN@[43; 44) "("
      ATTR@[44; 52)
        POUND@[44; 45) "#"
-        TOKEN_TREE@[45; 52)
+        L_BRACK@[45; 46) "["
-          L_BRACK@[45; 46) "["
+        PATH@[46; 51)
-          IDENT@[46; 51) "attr1"
+          PATH_SEGMENT@[46; 51)
-          R_BRACK@[51; 52) "]"
+            NAME_REF@[46; 51)
+              IDENT@[46; 51) "attr1"
+        R_BRACK@[51; 52) "]"
      WHITESPACE@[52; 53) " "
      PARAM@[53; 58)
        BIND_PAT@[53; 54)
@@ -105,10 +111,12 @@ SOURCE_FILE@[0; 519)
          WHITESPACE@[105; 106) " "
          ATTR@[106; 113)
            POUND@[106; 107) "#"
-            TOKEN_TREE@[107; 113)
+            L_BRACK@[107; 108) "["
-              L_BRACK@[107; 108) "["
+            PATH@[108; 112)
-              IDENT@[108; 112) "attr"
+              PATH_SEGMENT@[108; 112)
-              R_BRACK@[112; 113) "]"
+                NAME_REF@[108; 112)
+                  IDENT@[108; 112) "attr"
+            R_BRACK@[112; 113) "]"
          WHITESPACE@[113; 114) " "
          DOTDOTDOT@[114; 117) "..."
          R_PAREN@[117; 118) ")"
@@ -148,10 +156,12 @@ SOURCE_FILE@[0; 519)
                    L_PAREN@[145; 146) "("
                    ATTR@[146; 153)
                      POUND@[146; 147) "#"
-                      TOKEN_TREE@[147; 153)
+                      L_BRACK@[147; 148) "["
-                        L_BRACK@[147; 148) "["
+                      PATH@[148; 152)
-                        IDENT@[148; 152) "attr"
+                        PATH_SEGMENT@[148; 152)
-                        R_BRACK@[152; 153) "]"
+                          NAME_REF@[148; 152)
+                            IDENT@[148; 152) "attr"
+                      R_BRACK@[152; 153) "]"
                    WHITESPACE@[153; 154) " "
                    PARAM@[154; 166)
                      REFERENCE_TYPE@[154; 166)
@@ -196,10 +206,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[196; 197) "("
          ATTR@[197; 204)
            POUND@[197; 198) "#"
-            TOKEN_TREE@[198; 204)
+            L_BRACK@[198; 199) "["
-              L_BRACK@[198; 199) "["
+            PATH@[199; 203)
-              IDENT@[199; 203) "attr"
+              PATH_SEGMENT@[199; 203)
-              R_BRACK@[203; 204) "]"
+                NAME_REF@[199; 203)
+                  IDENT@[199; 203) "attr"
+            R_BRACK@[203; 204) "]"
          WHITESPACE@[204; 205) " "
          PARAM@[205; 211)
            PLACEHOLDER_PAT@[205; 206)
@@ -216,10 +228,12 @@ SOURCE_FILE@[0; 519)
          ATTR@[213; 221)
            POUND@[213; 214) "#"
            WHITESPACE@[214; 215) " "
-            TOKEN_TREE@[215; 221)
+            L_BRACK@[215; 216) "["
-              L_BRACK@[215; 216) "["
+            PATH@[216; 220)
-              IDENT@[216; 220) "attr"
+              PATH_SEGMENT@[216; 220)
-              R_BRACK@[220; 221) "]"
+                NAME_REF@[216; 220)
+                  IDENT@[216; 220) "attr"
+            R_BRACK@[220; 221) "]"
          WHITESPACE@[221; 222) " "
          PARAM@[222; 232)
            BIND_PAT@[222; 227)
@@ -260,10 +274,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[256; 257) "("
          ATTR@[257; 268)
            POUND@[257; 258) "#"
-            TOKEN_TREE@[258; 268)
+            L_BRACK@[258; 259) "["
-              L_BRACK@[258; 259) "["
+            PATH@[259; 267)
-              IDENT@[259; 267) "must_use"
+              PATH_SEGMENT@[259; 267)
-              R_BRACK@[267; 268) "]"
+                NAME_REF@[259; 267)
+                  IDENT@[259; 267) "must_use"
+            R_BRACK@[267; 268) "]"
          WHITESPACE@[268; 269) " "
          SELF_PARAM@[269; 273)
            SELF_KW@[269; 273) "self"
@@ -283,10 +299,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[288; 289) "("
          ATTR@[289; 296)
            POUND@[289; 290) "#"
-            TOKEN_TREE@[290; 296)
+            L_BRACK@[290; 291) "["
-              L_BRACK@[290; 291) "["
+            PATH@[291; 295)
-              IDENT@[291; 295) "attr"
+              PATH_SEGMENT@[291; 295)
-              R_BRACK@[295; 296) "]"
+                NAME_REF@[291; 295)
+                  IDENT@[291; 295) "attr"
+            R_BRACK@[295; 296) "]"
          WHITESPACE@[296; 297) " "
          SELF_PARAM@[297; 301)
            SELF_KW@[297; 301) "self"
@@ -306,10 +324,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[316; 317) "("
          ATTR@[317; 324)
            POUND@[317; 318) "#"
-            TOKEN_TREE@[318; 324)
+            L_BRACK@[318; 319) "["
-              L_BRACK@[318; 319) "["
+            PATH@[319; 323)
-              IDENT@[319; 323) "attr"
+              PATH_SEGMENT@[319; 323)
-              R_BRACK@[323; 324) "]"
+                NAME_REF@[319; 323)
+                  IDENT@[319; 323) "attr"
+            R_BRACK@[323; 324) "]"
          WHITESPACE@[324; 325) " "
          SELF_PARAM@[325; 330)
            AMP@[325; 326) "&"
@@ -335,10 +355,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[349; 350) "("
          ATTR@[350; 357)
            POUND@[350; 351) "#"
-            TOKEN_TREE@[351; 357)
+            L_BRACK@[351; 352) "["
-              L_BRACK@[351; 352) "["
+            PATH@[352; 356)
-              IDENT@[352; 356) "attr"
+              PATH_SEGMENT@[352; 356)
-              R_BRACK@[356; 357) "]"
+                NAME_REF@[352; 356)
+                  IDENT@[352; 356) "attr"
+            R_BRACK@[356; 357) "]"
          WHITESPACE@[357; 358) " "
          SELF_PARAM@[358; 367)
            AMP@[358; 359) "&"
@@ -366,10 +388,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[386; 387) "("
          ATTR@[387; 394)
            POUND@[387; 388) "#"
-            TOKEN_TREE@[388; 394)
+            L_BRACK@[388; 389) "["
-              L_BRACK@[388; 389) "["
+            PATH@[389; 393)
-              IDENT@[389; 393) "attr"
+              PATH_SEGMENT@[389; 393)
-              R_BRACK@[393; 394) "]"
+                NAME_REF@[389; 393)
+                  IDENT@[389; 393) "attr"
+            R_BRACK@[393; 394) "]"
          WHITESPACE@[394; 395) " "
          SELF_PARAM@[395; 403)
            AMP@[395; 396) "&"
@@ -397,10 +421,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[422; 423) "("
          ATTR@[423; 430)
            POUND@[423; 424) "#"
-            TOKEN_TREE@[424; 430)
+            L_BRACK@[424; 425) "["
-              L_BRACK@[424; 425) "["
+            PATH@[425; 429)
-              IDENT@[425; 429) "attr"
+              PATH_SEGMENT@[425; 429)
-              R_BRACK@[429; 430) "]"
+                NAME_REF@[425; 429)
+                  IDENT@[425; 429) "attr"
+            R_BRACK@[429; 430) "]"
          WHITESPACE@[430; 431) " "
          SELF_PARAM@[431; 443)
            AMP@[431; 432) "&"
@@ -425,10 +451,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[457; 458) "("
          ATTR@[458; 465)
            POUND@[458; 459) "#"
-            TOKEN_TREE@[459; 465)
+            L_BRACK@[459; 460) "["
-              L_BRACK@[459; 460) "["
+            PATH@[460; 464)
-              IDENT@[460; 464) "attr"
+              PATH_SEGMENT@[460; 464)
-              R_BRACK@[464; 465) "]"
+                NAME_REF@[460; 464)
+                  IDENT@[460; 464) "attr"
+            R_BRACK@[464; 465) "]"
          WHITESPACE@[465; 466) " "
          SELF_PARAM@[466; 476)
            SELF_KW@[466; 470) "self"
@@ -455,10 +483,12 @@ SOURCE_FILE@[0; 519)
          L_PAREN@[490; 491) "("
          ATTR@[491; 498)
            POUND@[491; 492) "#"
-            TOKEN_TREE@[492; 498)
+            L_BRACK@[492; 493) "["
-              L_BRACK@[492; 493) "["
+            PATH@[493; 497)
-              IDENT@[493; 497) "attr"
+              PATH_SEGMENT@[493; 497)
-              R_BRACK@[497; 498) "]"
+                NAME_REF@[493; 497)
+                  IDENT@[493; 497) "attr"
+            R_BRACK@[497; 498) "]"
          WHITESPACE@[498; 499) " "
          SELF_PARAM@[499; 513)
            SELF_KW@[499; 503) "self"
diff --git a/crates/ra_syntax/test_data/parser/ok/0053_outer_attribute_on_macro_rules.txt b/crates/ra_syntax/test_data/parser/ok/0053_outer_attribute_on_macro_rules.txt
index f77221f76..04ff0e2ff 100644
--- a/crates/ra_syntax/test_data/parser/ok/0053_outer_attribute_on_macro_rules.txt
+++ b/crates/ra_syntax/test_data/parser/ok/0053_outer_attribute_on_macro_rules.txt
@@ -4,10 +4,12 @@ SOURCE_FILE@[0; 65)
    WHITESPACE@[13; 14) "\n"
    ATTR@[14; 29)
      POUND@[14; 15) "#"
-      TOKEN_TREE@[15; 29)
+      L_BRACK@[15; 16) "["
-        L_BRACK@[15; 16) "["
+      PATH@[16; 28)
-        IDENT@[16; 28) "macro_export"
+        PATH_SEGMENT@[16; 28)
-        R_BRACK@[28; 29) "]"
+          NAME_REF@[16; 28)
+            IDENT@[16; 28) "macro_export"
+      R_BRACK@[28; 29) "]"
    WHITESPACE@[29; 30) "\n"
    PATH@[30; 41)
      PATH_SEGMENT@[30; 41)
diff --git a/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.rs b/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.rs
new file mode 100644
index 000000000..100fccc64
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.rs
@@ -0,0 +1,7 @@
+fn foo() {
+    1 + *&2 + 3;
+    *&1 as u64;
+    *x(1);
+    &x[1];
+    -1..2;
+}
diff --git a/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.txt b/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.txt
new file mode 100644
index 000000000..d30cb63ff
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0058_unary_expr_precedence.txt
@@ -0,0 +1,97 @@
+SOURCE_FILE@[0; 79)
+  FN_DEF@[0; 78)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK_EXPR@[9; 78)
+      BLOCK@[9; 78)
+        L_CURLY@[9; 10) "{"
+        WHITESPACE@[10; 15) "\n    "
+        EXPR_STMT@[15; 27)
+          BIN_EXPR@[15; 26)
+            BIN_EXPR@[15; 22)
+              LITERAL@[15; 16)
+                INT_NUMBER@[15; 16) "1"
+              WHITESPACE@[16; 17) " "
+              PLUS@[17; 18) "+"
+              WHITESPACE@[18; 19) " "
+              PREFIX_EXPR@[19; 22)
+                STAR@[19; 20) "*"
+                REF_EXPR@[20; 22)
+                  AMP@[20; 21) "&"
+                  LITERAL@[21; 22)
+                    INT_NUMBER@[21; 22) "2"
+            WHITESPACE@[22; 23) " "
+            PLUS@[23; 24) "+"
+            WHITESPACE@[24; 25) " "
+            LITERAL@[25; 26)
+              INT_NUMBER@[25; 26) "3"
+          SEMI@[26; 27) ";"
+        WHITESPACE@[27; 32) "\n    "
+        EXPR_STMT@[32; 43)
+          CAST_EXPR@[32; 42)
+            PREFIX_EXPR@[32; 35)
+              STAR@[32; 33) "*"
+              REF_EXPR@[33; 35)
+                AMP@[33; 34) "&"
+                LITERAL@[34; 35)
+                  INT_NUMBER@[34; 35) "1"
+            WHITESPACE@[35; 36) " "
+            AS_KW@[36; 38) "as"
+            WHITESPACE@[38; 39) " "
+            PATH_TYPE@[39; 42)
+              PATH@[39; 42)
+                PATH_SEGMENT@[39; 42)
+                  NAME_REF@[39; 42)
+                    IDENT@[39; 42) "u64"
+          SEMI@[42; 43) ";"
+        WHITESPACE@[43; 48) "\n    "
+        EXPR_STMT@[48; 54)
+          PREFIX_EXPR@[48; 53)
+            STAR@[48; 49) "*"
+            CALL_EXPR@[49; 53)
+              PATH_EXPR@[49; 50)
+                PATH@[49; 50)
+                  PATH_SEGMENT@[49; 50)
+                    NAME_REF@[49; 50)
+                      IDENT@[49; 50) "x"
+              ARG_LIST@[50; 53)
+                L_PAREN@[50; 51) "("
+                LITERAL@[51; 52)
+                  INT_NUMBER@[51; 52) "1"
+                R_PAREN@[52; 53) ")"
+          SEMI@[53; 54) ";"
+        WHITESPACE@[54; 59) "\n    "
+        EXPR_STMT@[59; 65)
+          REF_EXPR@[59; 64)
+            AMP@[59; 60) "&"
+            INDEX_EXPR@[60; 64)
+              PATH_EXPR@[60; 61)
+                PATH@[60; 61)
+                  PATH_SEGMENT@[60; 61)
+                    NAME_REF@[60; 61)
+                      IDENT@[60; 61) "x"
+              L_BRACK@[61; 62) "["
+              LITERAL@[62; 63)
+                INT_NUMBER@[62; 63) "1"
+              R_BRACK@[63; 64) "]"
+          SEMI@[64; 65) ";"
+        WHITESPACE@[65; 70) "\n    "
+        EXPR_STMT@[70; 76)
+          RANGE_EXPR@[70; 75)
+            PREFIX_EXPR@[70; 72)
+              MINUS@[70; 71) "-"
+              LITERAL@[71; 72)
+                INT_NUMBER@[71; 72) "1"
+            DOTDOT@[72; 74) ".."
+            LITERAL@[74; 75)
+              INT_NUMBER@[74; 75) "2"
+          SEMI@[75; 76) ";"
+        WHITESPACE@[76; 77) "\n"
+        R_CURLY@[77; 78) "}"
+  WHITESPACE@[78; 79) "\n"
diff --git a/crates/ra_text_edit/src/lib.rs b/crates/ra_text_edit/src/lib.rs
index df673ba18..5f1b12222 100644
--- a/crates/ra_text_edit/src/lib.rs
+++ b/crates/ra_text_edit/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod text_edit;
 pub mod test_utils;
diff --git a/crates/ra_text_edit/src/test_utils.rs b/crates/ra_text_edit/src/test_utils.rs
index 2d6e7f216..d4c7840ff 100644
--- a/crates/ra_text_edit/src/test_utils.rs
+++ b/crates/ra_text_edit/src/test_utils.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{AtomTextEdit, TextEdit};
 use proptest::prelude::*;
 use text_unit::{TextRange, TextUnit};
diff --git a/crates/ra_text_edit/src/text_edit.rs b/crates/ra_text_edit/src/text_edit.rs
index 8522f99bd..0381ea000 100644
--- a/crates/ra_text_edit/src/text_edit.rs
+++ b/crates/ra_text_edit/src/text_edit.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::AtomTextEdit;
 use text_unit::{TextRange, TextUnit};
diff --git a/crates/ra_tools/Cargo.toml b/crates/ra_tools/Cargo.toml
index 848ca408d..9cceacee3 100644
--- a/crates/ra_tools/Cargo.toml
+++ b/crates/ra_tools/Cargo.toml
@@ -8,7 +8,7 @@ publish = false
 [dependencies]
 walkdir = "2.1.3"
 itertools = "0.8.0"
-pico-args = "0.2.0"
+pico-args = "0.3.0"
 quote = "1.0.2"
 proc-macro2 = "1.0.1"
 ron = "0.5.1"
diff --git a/crates/ra_tools/src/bin/pre-commit.rs b/crates/ra_tools/src/bin/pre-commit.rs
index a628f64b2..16bbf9cb2 100644
--- a/crates/ra_tools/src/bin/pre-commit.rs
+++ b/crates/ra_tools/src/bin/pre-commit.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::process::Command;
 use ra_tools::{project_root, run, run_rustfmt, Overwrite, Result};
diff --git a/crates/ra_tools/src/boilerplate_gen.rs b/crates/ra_tools/src/boilerplate_gen.rs
index 1d112c0af..39f1cae66 100644
--- a/crates/ra_tools/src/boilerplate_gen.rs
+++ b/crates/ra_tools/src/boilerplate_gen.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use std::{
    collections::BTreeMap,
    fs,
@@ -282,7 +284,7 @@ fn reformat(text: impl std::fmt::Display) -> Result<String> {
    let output = rustfmt.wait_with_output()?;
    let stdout = String::from_utf8(output.stdout)?;
    let preamble = "Generated file, do not edit by hand, see `crate/ra_tools/src/codegen`";
-    Ok(format!("// {}\n\n{}", preamble, stdout))
+    Ok(format!("//! {}\n\n{}", preamble, stdout))
 }
 #[derive(Deserialize, Debug)]
diff --git a/crates/ra_tools/src/help.rs b/crates/ra_tools/src/help.rs
index 9eb4dfbe4..72dfabacd 100644
--- a/crates/ra_tools/src/help.rs
+++ b/crates/ra_tools/src/help.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 pub const GLOBAL_HELP: &str = "tasks
 USAGE:
diff --git a/crates/ra_tools/src/lib.rs b/crates/ra_tools/src/lib.rs
index 9ba23caaa..aa993a38a 100644
--- a/crates/ra_tools/src/lib.rs
+++ b/crates/ra_tools/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod boilerplate_gen;
 use std::{
diff --git a/crates/ra_tools/src/main.rs b/crates/ra_tools/src/main.rs
index a951ce427..161871ccf 100644
--- a/crates/ra_tools/src/main.rs
+++ b/crates/ra_tools/src/main.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 mod help;
 use core::fmt::Write;
diff --git a/crates/ra_tools/tests/cli.rs b/crates/ra_tools/tests/cli.rs
index 91b19c8f8..609fd4d8b 100644
--- a/crates/ra_tools/tests/cli.rs
+++ b/crates/ra_tools/tests/cli.rs
@@ -1,6 +1,5 @@
-use walkdir::WalkDir;
 use ra_tools::{gen_tests, generate_boilerplate, project_root, run_rustfmt, Verify};
+use walkdir::WalkDir;
 #[test]
 fn generated_grammar_is_fresh() {
@@ -36,7 +35,7 @@ fn no_todo() {
        let text = std::fs::read_to_string(e.path()).unwrap();
        if text.contains("TODO") || text.contains("TOOD") {
            panic!(
-                "\nTODO markers should not be commited to the master branch,\n\
+                "\nTODO markers should not be committed to the master branch,\n\
                 use FIXME instead\n\
                 {}\n",
                e.path().display(),
diff --git a/crates/ra_tools/tests/docs.rs b/crates/ra_tools/tests/docs.rs
new file mode 100644
index 000000000..ea3330175
--- /dev/null
+++ b/crates/ra_tools/tests/docs.rs
@@ -0,0 +1,63 @@
+use std::fs;
+use std::io::prelude::*;
+use std::io::BufReader;
+use std::path::Path;
+use walkdir::{DirEntry, WalkDir};
+use ra_tools::project_root;
+fn is_exclude_dir(p: &Path) -> bool {
+    let exclude_dirs = ["tests", "test_data"];
+    let mut cur_path = p;
+    while let Some(path) = cur_path.parent() {
+        if exclude_dirs.iter().any(|dir| path.ends_with(dir)) {
+            return true;
+        }
+        cur_path = path;
+    }
+    false
+}
+fn is_exclude_file(d: &DirEntry) -> bool {
+    let file_names = ["tests.rs"];
+    d.file_name().to_str().map(|f_n| file_names.iter().any(|name| *name == f_n)).unwrap_or(false)
+}
+fn is_hidden(entry: &DirEntry) -> bool {
+    entry.file_name().to_str().map(|s| s.starts_with(".")).unwrap_or(false)
+}
+#[test]
+fn no_docs_comments() {
+    let crates = project_root().join("crates");
+    let iter = WalkDir::new(crates);
+    for f in iter.into_iter().filter_entry(|e| !is_hidden(e)) {
+        let f = f.unwrap();
+        if f.file_type().is_dir() {
+            continue;
+        }
+        if f.path().extension().map(|it| it != "rs").unwrap_or(false) {
+            continue;
+        }
+        if is_exclude_dir(f.path()) {
+            continue;
+        }
+        if is_exclude_file(&f) {
+            continue;
+        }
+        let mut reader = BufReader::new(fs::File::open(f.path()).unwrap());
+        let mut line = String::new();
+        reader.read_line(&mut line).unwrap();
+        if !line.starts_with("//!") {
+            panic!(
+                "\nMissing docs strings\n\
+                 module: {}\n\
+                 Need add doc for module\n",
+                f.path().display()
+            )
+        }
+    }
+}
diff --git a/crates/ra_tools/tests/main.rs b/crates/ra_tools/tests/main.rs
new file mode 100644
index 000000000..56d1318d6
--- /dev/null
+++ b/crates/ra_tools/tests/main.rs
@@ -0,0 +1,2 @@
+mod cli;
+mod docs;
diff --git a/crates/ra_tt/src/buffer.rs b/crates/ra_tt/src/buffer.rs
index 48c22a2d8..ef3f2323c 100644
--- a/crates/ra_tt/src/buffer.rs
+++ b/crates/ra_tt/src/buffer.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 use crate::{Subtree, TokenTree};
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
diff --git a/crates/ra_tt/src/lib.rs b/crates/ra_tt/src/lib.rs
index 2a48c66c4..20c251ff4 100644
--- a/crates/ra_tt/src/lib.rs
+++ b/crates/ra_tt/src/lib.rs
@@ -1,6 +1,6 @@
-/// `tt` crate defines a `TokenTree` data structure: this is the interface (both
+//! `tt` crate defines a `TokenTree` data structure: this is the interface (both
-/// input and output) of macros. It closely mirrors `proc_macro` crate's
+//! input and output) of macros. It closely mirrors `proc_macro` crate's
-/// `TokenTree`.
+//! `TokenTree`.
 macro_rules! impl_froms {
    ($e:ident: $($v:ident), *) => {
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 816d01f09..c40943b63 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -1,3 +1,5 @@
+//! FIXME: write short doc here
 #[macro_use]
 pub mod marks;
diff --git a/docs/dev/architecture.md b/docs/dev/architecture.md
index 1201f6e5a..1ffabc6ef 100644
--- a/docs/dev/architecture.md
+++ b/docs/dev/architecture.md
@@ -79,9 +79,7 @@ Rust syntax tree structure and parser. See
 - `grammar.ron` RON description of the grammar, which is used to
  generate `syntax_kinds` and `ast` modules, using `cargo gen-syntax` command.
 - `algo`: generic tree algorithms, including `walk` for O(1) stack
-  space tree traversal (this is cool) and `visit` for type-driven
+  space tree traversal (this is cool).
-  visiting the nodes (this is double plus cool, if you understand how
-  `Visitor` works, you understand the design of syntax trees).
 Tests for ra_syntax are mostly data-driven: `test_data/parser` contains subdirectories with a bunch of `.rs`
 (test vectors) and `.txt` files with corresponding syntax trees. During testing, we check
diff --git a/docs/user/README.md b/docs/user/README.md
index 9d03cad1c..036b51d58 100644
--- a/docs/user/README.md
+++ b/docs/user/README.md
@@ -45,7 +45,7 @@ should adapt these manual installation instructions:
 ```
 $ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
 $ cd rust-analyzer
-$ cargo install --path ./crates/ra_lsp_server/ --force
+$ cargo install --path ./crates/ra_lsp_server/ --force --locked
 $ cd ./editors/code
 $ npm install
 $ ./node_modules/vsce/out/vsce package
@@ -116,6 +116,22 @@ to load path and require it in `init.el`
 [coc-vim-conf]: https://github.com/neoclide/coc.nvim/#example-vim-configuration
 [coc-rust-analyzer]: https://github.com/fannheyward/coc-rust-analyzer
+## Vim and NeoVim Alternative
+* Install LanguageClient-neovim by following the instructions [here][lang-client-neovim]
+  - No extra run-time is required as this server is written in Rust
+  - The github project wiki has extra tips on configuration
+* Configure by adding this to your vim/neovim config file (replacing the existing rust specific line if it exists):
+```
+let g:LanguageClient_serverCommands = {
+\ 'rust': ['ra_lsp_server'],
+\ }
+```
+[lang-client-neovim]: https://github.com/autozimu/LanguageClient-neovim
 ## Sublime Text 3
diff --git a/docs/user/features.md b/docs/user/features.md
index 23842f409..8b7a8d7fc 100644
--- a/docs/user/features.md
+++ b/docs/user/features.md
@@ -166,6 +166,20 @@ impl Foo for S {
 }
 ```
+- Apply [De Morgan's law](https://en.wikipedia.org/wiki/De_Morgan%27s_laws)
+```rust
+// before:
+fn example(x: bool) -> bool {
+    !x || !x
+}
+// after:
+fn example(x: bool) -> bool {
+    !(x && x)
+}
+```
 - Import path
 ```rust
@@ -353,9 +367,9 @@ impl VariantData {
 ```rust
 // before:
-use algo:<|>:visitor::{Visitor, visit};
+use crate:<|>:db::{RootDatabase, FileSymbol};
 // after:
-use algo::{<|>visitor::{Visitor, visit}};
+use crate::{<|>db::{RootDatabase, FileSymbol}};
 ```
 - Flip binary expression
diff --git a/editors/code/src/test/utils/diagnotics/rust.test.ts b/editors/code/src/test/utils/diagnotics/rust.test.ts
index 7fb003fe2..327d15046 100644
--- a/editors/code/src/test/utils/diagnotics/rust.test.ts
+++ b/editors/code/src/test/utils/diagnotics/rust.test.ts
@@ -50,7 +50,7 @@ describe('mapRustDiagnosticToVsCode', () => {
            ].join('\n')
        );
        assert.strictEqual(diagnostic.code, 'E0053');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
        // No related information
        assert.deepStrictEqual(diagnostic.relatedInformation, []);
@@ -115,7 +115,7 @@ describe('mapRustDiagnosticToVsCode', () => {
        );
        assert.strictEqual(diagnostic.code, 'E0061');
        assert.strictEqual(diagnostic.source, 'rustc');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
        // One related information for the original definition
        const relatedInformation = diagnostic.relatedInformation;
@@ -149,7 +149,7 @@ describe('mapRustDiagnosticToVsCode', () => {
            ].join('\n')
        );
        assert.strictEqual(diagnostic.code, 'trivially_copy_pass_by_ref');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
        // One related information for the lint definition
        const relatedInformation = diagnostic.relatedInformation;
@@ -189,7 +189,7 @@ describe('mapRustDiagnosticToVsCode', () => {
        );
        assert.strictEqual(diagnostic.code, 'E0308');
        assert.strictEqual(diagnostic.source, 'rustc');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
        // No related information
        assert.deepStrictEqual(diagnostic.relatedInformation, []);
diff --git a/editors/code/src/utils/diagnostics/rust.ts b/editors/code/src/utils/diagnostics/rust.ts
index 1fb1f7b6d..0550d0372 100644
--- a/editors/code/src/utils/diagnostics/rust.ts
+++ b/editors/code/src/utils/diagnostics/rust.ts
@@ -112,6 +112,17 @@ function isUnusedOrUnnecessary(rd: RustDiagnostic): boolean {
 }
 /**
+ * Determines if diagnostic is related to deprecated code
+ */
+function isDeprecated(rd: RustDiagnostic): boolean {
+    if (!rd.code) {
+        return false;
+    }
+    return ['deprecated'].includes(rd.code.code);
+}
+/**
 * Converts a Rust child diagnostic to a VsCode related information
 *
 * This can have three outcomes:
@@ -200,6 +211,7 @@ export function mapRustDiagnosticToVsCode(
    vd.source = source;
    vd.code = code;
    vd.relatedInformation = [];
+    vd.tags = [];
    for (const secondarySpan of secondarySpans) {
        const related = mapSecondarySpanToRelated(secondarySpan);
@@ -234,7 +246,11 @@ export function mapRustDiagnosticToVsCode(
    }
    if (isUnusedOrUnnecessary(rd)) {
-        vd.tags = [vscode.DiagnosticTag.Unnecessary];
+        vd.tags.push(vscode.DiagnosticTag.Unnecessary);
+    }
+    if (isDeprecated(rd)) {
+        vd.tags.push(vscode.DiagnosticTag.Deprecated);
    }
    return {