87 files changed, 1073 insertions, 714 deletions
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index ece1fd364..a97ed24ba 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -118,6 +118,37 @@ jobs:
        name: dist-x86_64-unknown-linux-gnu
        path: ./dist
+  dist-aarch64-unknown-linux-gnu:
+    name: dist (aarch64-unknown-linux-gnu)
+    runs-on: ubuntu-16.04
+    env:
+      RA_TARGET: aarch64-unknown-linux-gnu
+      CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+    - name: Install Rust toolchain
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: stable
+        target: aarch64-unknown-linux-gnu
+        profile: minimal
+        override: true
+    - name: Install target toolchain
+      run: sudo apt-get install gcc-aarch64-linux-gnu
+    - name: Dist
+      run: cargo xtask dist
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v1
+      with:
+        name: dist-aarch64-unknown-linux-gnu
+        path: ./dist
  dist-x86_64-apple-darwin:
    name: dist (x86_64-apple-darwin)
    runs-on: macos-latest
@@ -174,7 +205,7 @@ jobs:
  publish:
    name: publish
    runs-on: ubuntu-16.04
-    needs: ['dist-x86_64-pc-windows-msvc', 'dist-aarch64-pc-windows-msvc', 'dist-x86_64-unknown-linux-gnu', 'dist-x86_64-apple-darwin', 'dist-aarch64-apple-darwin']
+    needs: ['dist-x86_64-pc-windows-msvc', 'dist-aarch64-pc-windows-msvc', 'dist-x86_64-unknown-linux-gnu', 'dist-aarch64-unknown-linux-gnu', 'dist-x86_64-apple-darwin', 'dist-aarch64-apple-darwin']
    steps:
    - name: Install Nodejs
      uses: actions/setup-node@v1
@@ -207,6 +238,10 @@ jobs:
        path: dist
    - uses: actions/download-artifact@v1
      with:
+        name: dist-aarch64-unknown-linux-gnu
+        path: dist
+    - uses: actions/download-artifact@v1
+      with:
        name: dist-x86_64-pc-windows-msvc
        path: dist
    - uses: actions/download-artifact@v1
diff --git a/Cargo.lock b/Cargo.lock
index db8b49122..f01544324 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,9 +26,9 @@ dependencies = [
 [[package]]
 name = "anyhow"
-version = "1.0.37"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee67c11feeac938fae061b232e38e0b6d94f97a9df10e6271319325ac4c56a86"
+checksum = "afddf7f520a80dbf76e6f50a35bca42a2331ef227a28b3b6dc5c2e2338d114b1"
 [[package]]
 name = "anymap"
@@ -118,9 +118,9 @@ checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 [[package]]
 name = "byteorder"
-version = "1.3.4"
+version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
+checksum = "ae44d1a3d5a19df61dd0c8beb138458ac2a53a7ac09eba97d55592540004306b"
 [[package]]
 name = "cargo-platform"
@@ -133,9 +133,9 @@ dependencies = [
 [[package]]
 name = "cargo_metadata"
-version = "0.12.2"
+version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11a47b6286279a9998588ef7050d1ebc2500c69892a557c90fe5d071c64415dc"
+checksum = "7714a157da7991e23d90686b9524b9e12e0407a108647f52e9328f4b3d51ac7f"
 dependencies = [
 "cargo-platform",
 "semver",
@@ -269,9 +269,9 @@ dependencies = [
 [[package]]
 name = "const_fn"
-version = "0.4.4"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd51eab21ab4fd6a3bf889e2d0958c0a6e3a61ad04260325e919e652a2a62826"
+checksum = "28b9d6de7f49e22cf97ad17fc4036ece69300032f45f78f30b4a4482cdc3f4a6"
 [[package]]
 name = "crc32fast"
@@ -449,6 +449,12 @@ dependencies = [
 ]
 [[package]]
+name = "fs_extra"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2022715d62ab30faffd124d40b76f4134a550a87792276512b18d63272333394"
+[[package]]
 name = "fsevent"
 version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -502,6 +508,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 [[package]]
+name = "hashbrown"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2140e9c963869f01789fa4fef4805211081ec794af5fc77c0d5b377906118853"
+[[package]]
 name = "heck"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -512,9 +524,9 @@ dependencies = [
 [[package]]
 name = "hermit-abi"
-version = "0.1.17"
+version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aca5565f760fb5b220e499d72710ed156fdb74e631659e99377d9ebfbd13ae8"
+checksum = "322f4de77956e22ed0e5032c359a0f1273f1f7f0d79bfa3b8ffbc730d7fbcc5c"
 dependencies = [
 "libc",
 ]
@@ -552,7 +564,7 @@ dependencies = [
 "hir_expand",
 "indexmap",
 "itertools 0.10.0",
- "la-arena 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "la-arena",
 "log",
 "mbe",
 "once_cell",
@@ -571,7 +583,7 @@ version = "0.0.0"
 dependencies = [
 "base_db",
 "either",
- "la-arena 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "la-arena",
 "log",
 "mbe",
 "parser",
@@ -596,7 +608,7 @@ dependencies = [
 "hir_def",
 "hir_expand",
 "itertools 0.10.0",
- "la-arena 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "la-arena",
 "log",
 "once_cell",
 "profile",
@@ -686,7 +698,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fb1fa934250de4de8aef298d81c729a7d33d8c239daa3a7575e6b92bfc7313b"
 dependencies = [
 "autocfg",
- "hashbrown",
+ "hashbrown 0.9.1",
 ]
 [[package]]
@@ -702,9 +714,9 @@ dependencies = [
 [[package]]
 name = "inotify-sys"
-version = "0.1.4"
+version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4563555856585ab3180a5bf0b2f9f8d301a728462afffc8195b3f5394229c55"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
 dependencies = [
 "libc",
 ]
@@ -752,6 +764,38 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd25036021b0de88a0aff6b850051563c6516d0bf53f8638938edbb9de732736"
 [[package]]
+name = "jemalloc-ctl"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c502a5ff9dd2924f1ed32ba96e3b65735d837b4bfd978d3161b1702e66aca4b7"
+dependencies = [
+ "jemalloc-sys",
+ "libc",
+ "paste",
+]
+[[package]]
+name = "jemalloc-sys"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d3b9f3f5c9b31aa0f5ed3260385ac205db665baa41d49bb8338008ae94ede45"
+dependencies = [
+ "cc",
+ "fs_extra",
+ "libc",
+]
+[[package]]
+name = "jemallocator"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43ae63fcfc45e99ab3d1b29a46782ad679e98436c3169d15a167a1108a724b69"
+dependencies = [
+ "jemalloc-sys",
+ "libc",
+]
+[[package]]
 name = "jod-thread"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -769,13 +813,7 @@ dependencies = [
 [[package]]
 name = "la-arena"
-version = "0.1.1"
+version = "0.2.0"
-[[package]]
-name = "la-arena"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "383ed2a74426d1051751f6483a7160b98f36068224857cd4c953b34719476fc3"
 [[package]]
 name = "lazy_static"
@@ -791,15 +829,15 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 [[package]]
 name = "libc"
-version = "0.2.81"
+version = "0.2.82"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1482821306169ec4d07f6aca392a4681f66c75c9918aa49641a2595db64053cb"
+checksum = "89203f3fba0a3795506acaad8ebce3c80c0af93f994d5a1d7a0b1eeb23271929"
 [[package]]
 name = "libloading"
-version = "0.6.6"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9367bdfa836b7e3cf895867f7a570283444da90562980ec2263d6e1569b16bc"
+checksum = "351a32417a12d5f7e82c368a66781e307834dae04c6ce0cd4456d52989229883"
 dependencies = [
 "cfg-if 1.0.0",
 "winapi 0.3.9",
@@ -825,9 +863,9 @@ dependencies = [
 [[package]]
 name = "log"
-version = "0.4.11"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
+checksum = "fcf3805d4480bb5b86070dcfeb9e2cb2ebc148adb753c5cca5f884d1d65a42b2"
 dependencies = [
 "cfg-if 0.1.10",
 ]
@@ -1105,6 +1143,25 @@ dependencies = [
 ]
 [[package]]
+name = "paste"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45ca20c77d80be666aef2b45486da86238fabe33e38306bd3118fe4af33fa880"
+dependencies = [
+ "paste-impl",
+ "proc-macro-hack",
+]
+[[package]]
+name = "paste-impl"
+version = "0.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d95a7db200b97ef370c8e6de0088252f7e0dfff7d047a28528e47456c0fc98b6"
+dependencies = [
+ "proc-macro-hack",
+]
+[[package]]
 name = "paths"
 version = "0.0.0"
@@ -1160,9 +1217,15 @@ checksum = "28b9b4df73455c861d7cbf8be42f01d3b373ed7f02e378d55fa84eafc6f638b1"
 [[package]]
 name = "pin-project-lite"
-version = "0.2.0"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b063f57ec186e6140e2b8b6921e5f1bd89c7356dda5b33acc5401203ca6131c"
+checksum = "439697af366c49a6d0a010c56a0d97685bc140ce0d377b13a2ea2aa42d64a827"
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 [[package]]
 name = "proc-macro2"
@@ -1212,7 +1275,8 @@ name = "profile"
 version = "0.0.0"
 dependencies = [
 "cfg-if 1.0.0",
- "la-arena 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jemalloc-ctl",
+ "la-arena",
 "libc",
 "once_cell",
 "perf-event",
@@ -1227,10 +1291,11 @@ dependencies = [
 "cargo_metadata",
 "cfg",
 "itertools 0.10.0",
- "la-arena 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "la-arena",
 "log",
 "paths",
 "proc_macro_api",
+ "profile",
 "rustc-hash",
 "serde",
 "serde_json",
@@ -1300,9 +1365,9 @@ checksum = "41cc0f7e4d5d4544e8861606a285bb08d3e70712ccc7d2b84d7c0ccfaf4b05ce"
 [[package]]
 name = "regex"
-version = "1.4.2"
+version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38cf2c13ed4745de91a5eb834e11c00bcc3709e773173b2ce4c56c9fbde04b9c"
+checksum = "d9251239e129e16308e70d853559389de218ac275b515068abc96829d05b948a"
 dependencies = [
 "regex-syntax",
 ]
@@ -1319,16 +1384,17 @@ dependencies = [
 [[package]]
 name = "regex-syntax"
-version = "0.6.21"
+version = "0.6.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b181ba2dcf07aaccad5448e8ead58db5b742cf85dfe035e2227f137a539a189"
+checksum = "b5eb417147ba9860a96cfe72a0b93bf88fee1744b5636ec99ab20c1aa9376581"
 [[package]]
 name = "rowan"
-version = "0.10.1"
+version = "0.10.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca9516377b32367ade2fbe1846c75afa4827c8976f1c7d05d5473573d18a1a04"
+checksum = "e1898adeafc7d3c69913b33ee1acbbb39c726a9dbe05ff77c08b52957643e8db"
 dependencies = [
+ "hashbrown 0.10.0",
 "rustc-hash",
 "smol_str",
 "text-size",
@@ -1352,6 +1418,7 @@ dependencies = [
 "ide",
 "ide_db",
 "itertools 0.10.0",
+ "jemallocator",
 "jod-thread",
 "log",
 "lsp-server",
@@ -1483,18 +1550,18 @@ dependencies = [
 [[package]]
 name = "serde"
-version = "1.0.118"
+version = "1.0.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06c64263859d87aa2eb554587e2d23183398d617427327cf2b3d0ed8c69e4800"
+checksum = "9bdd36f49e35b61d49efd8aa7fc068fd295961fd2286d0b2ee9a4c7a14e99cc3"
 dependencies = [
 "serde_derive",
 ]
 [[package]]
 name = "serde_derive"
-version = "1.0.118"
+version = "1.0.119"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c84d3526699cd55261af4b941e4e725444df67aa4f9e6a3564f18030d12672df"
+checksum = "552954ce79a059ddd5fd68c271592374bd15cab2274970380c000118aeffe1cd"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -1550,9 +1617,9 @@ checksum = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 [[package]]
 name = "smallvec"
-version = "1.6.0"
+version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a55ca5f3b68e41c979bf8c46a6f1da892ca4db8f94023ce0bd32407573b1ac0"
+checksum = "fe0f37c9e8f3c5a4a66ad655a93c74daac4ad00c441533bf5c6e7990bb42604e"
 [[package]]
 name = "smol_str"
@@ -1592,9 +1659,9 @@ dependencies = [
 [[package]]
 name = "syn"
-version = "1.0.57"
+version = "1.0.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4211ce9909eb971f111059df92c45640aad50a619cf55cd76476be803c4c68e6"
+checksum = "cc60a3d73ea6594cd712d830cc1f0390fd71542d8c8cd24e70cc54cdfd5e05d5"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -1671,9 +1738,9 @@ dependencies = [
 [[package]]
 name = "thread_local"
-version = "1.0.1"
+version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d40c6d1b69745a6ec6fb1ca717914848da4b44ae29d9b3080cbee91d72a69b14"
+checksum = "bb9bc092d0d51e76b2b19d9d85534ffc9ec2db959a2523cdae0697e2972cd447"
 dependencies = [
 "lazy_static",
 ]
@@ -1837,9 +1904,9 @@ checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
 [[package]]
 name = "ungrammar"
-version = "1.8.0"
+version = "1.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e33a2183403af89252547c4219a06a6cc8aef6302fee67e10e8431866af3ee72"
+checksum = "f5901372c0f3a6a1a9d880aef134c8eaf5e54409343637508c0a344270b42d7b"
 [[package]]
 name = "unicase"
diff --git a/crates/assists/src/handlers/introduce_named_lifetime.rs b/crates/assists/src/handlers/introduce_named_lifetime.rs
index 3f5f44d69..02782eb6d 100644
--- a/crates/assists/src/handlers/introduce_named_lifetime.rs
+++ b/crates/assists/src/handlers/introduce_named_lifetime.rs
@@ -61,7 +61,7 @@ fn generate_fn_def_assist(
    // compute the location which implicitly has the same lifetime as the anonymous lifetime
    let loc_needing_lifetime = if let Some(self_param) = self_param {
        // if we have a self reference, use that
-        Some(self_param.self_token()?.text_range().start())
+        Some(self_param.name()?.syntax().text_range().start())
    } else {
        // otherwise, if there's a single reference parameter without a named liftime, use that
        let fn_params_without_lifetime: Vec<_> = param_list
diff --git a/crates/completion/src/completions/keyword.rs b/crates/completion/src/completions/keyword.rs
index c1af348dc..47e146128 100644
--- a/crates/completion/src/completions/keyword.rs
+++ b/crates/completion/src/completions/keyword.rs
@@ -99,7 +99,7 @@ pub(crate) fn complete_expr_keyword(acc: &mut Completions, ctx: &CompletionConte
        add_keyword(ctx, acc, "else if", "else if $0 {}");
    }
    if (ctx.has_item_list_or_source_file_parent) || ctx.block_expr_parent {
-        add_keyword(ctx, acc, "mod", "mod $0 {}");
+        add_keyword(ctx, acc, "mod", "mod $0");
    }
    if ctx.bind_pat_parent || ctx.ref_pat_parent {
        add_keyword(ctx, acc, "mut", "mut ");
diff --git a/crates/completion/src/item.rs b/crates/completion/src/item.rs
index 378bd2c70..4147853e7 100644
--- a/crates/completion/src/item.rs
+++ b/crates/completion/src/item.rs
@@ -401,7 +401,9 @@ impl Builder {
    pub(crate) fn set_detail(mut self, detail: Option<impl Into<String>>) -> Builder {
        self.detail = detail.map(Into::into);
        if let Some(detail) = &self.detail {
-            assert_never!(detail.contains('\n'), "multiline detail: {}", detail);
+            if assert_never!(detail.contains('\n'), "multiline detail: {}", detail) {
+                self.detail = Some(detail.splitn(2, '\n').next().unwrap().to_string());
+            }
        }
        self
    }
diff --git a/crates/hir_def/Cargo.toml b/crates/hir_def/Cargo.toml
index 5d21283f7..535221294 100644
--- a/crates/hir_def/Cargo.toml
+++ b/crates/hir_def/Cargo.toml
@@ -20,7 +20,7 @@ fst = { version = "0.4", default-features = false }
 itertools = "0.10.0"
 indexmap = "1.4.0"
 smallvec = "1.4.0"
-la-arena = "0.1.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
 stdx = { path = "../stdx", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index 237c3d3f9..06f0b9b18 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -8,7 +8,7 @@ use hir_expand::{
    name::{AsName, Name},
    InFile,
 };
-use la_arena::{map::ArenaMap, Arena};
+use la_arena::{Arena, ArenaMap};
 use syntax::ast::{self, NameOwner, VisibilityOwner};
 use tt::{Delimiter, DelimiterKind, Leaf, Subtree, TokenTree};
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 5a86823c2..1b09ff816 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -7,7 +7,7 @@ use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{hygiene::Hygiene, name::AsName, AstId, InFile};
 use itertools::Itertools;
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use mbe::ast_to_token_tree;
 use syntax::{
    ast::{self, AstNode, AttrsOwner},
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 43ee57277..344f0b6c0 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -16,7 +16,7 @@ use hir_expand::{
    ast_id_map::AstIdMap, diagnostics::DiagnosticSink, hygiene::Hygiene, AstId, ExpandResult,
    HirFileId, InFile, MacroDefId,
 };
-use la_arena::{map::ArenaMap, Arena};
+use la_arena::{Arena, ArenaMap};
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, AstPtr};
 use test_utils::mark;
diff --git a/crates/hir_def/src/db.rs b/crates/hir_def/src/db.rs
index 0506a7274..6ef9fe790 100644
--- a/crates/hir_def/src/db.rs
+++ b/crates/hir_def/src/db.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 use base_db::{salsa, CrateId, SourceDatabase, Upcast};
 use hir_expand::{db::AstDatabase, HirFileId};
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use syntax::SmolStr;
 use crate::{
diff --git a/crates/hir_def/src/expr.rs b/crates/hir_def/src/expr.rs
index a293df9f1..5be838f4a 100644
--- a/crates/hir_def/src/expr.rs
+++ b/crates/hir_def/src/expr.rs
@@ -13,7 +13,7 @@
 //! See also a neighboring `body` module.
 use hir_expand::name::Name;
-use la_arena::{Idx, RawId};
+use la_arena::{Idx, RawIdx};
 use syntax::ast::RangeOp;
 use crate::{
@@ -24,7 +24,7 @@ use crate::{
 pub type ExprId = Idx<Expr>;
 pub(crate) fn dummy_expr_id() -> ExprId {
-    ExprId::from_raw(RawId::from(!0))
+    ExprId::from_raw(RawIdx::from(!0))
 }
 pub type PatId = Idx<Pat>;
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 75eab791a..3ace3be1f 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -10,7 +10,7 @@ use hir_expand::{
    name::{name, AsName, Name},
    InFile,
 };
-use la_arena::{map::ArenaMap, Arena};
+use la_arena::{Arena, ArenaMap};
 use syntax::ast::{self, GenericParamsOwner, NameOwner, TypeBoundsOwner};
 use crate::{
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 91e42aa0d..ff62928df 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -20,7 +20,7 @@ use hir_expand::{
    name::{name, AsName, Name},
    HirFileId, InFile,
 };
-use la_arena::{Arena, Idx, RawId};
+use la_arena::{Arena, Idx, RawIdx};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use syntax::{ast, match_ast};
@@ -145,7 +145,6 @@ impl ItemTree {
                macro_calls,
                macro_rules,
                macro_defs,
-                exprs,
                vis,
                generics,
            } = &mut **data;
@@ -167,7 +166,6 @@ impl ItemTree {
            macro_calls.shrink_to_fit();
            macro_rules.shrink_to_fit();
            macro_defs.shrink_to_fit();
-            exprs.shrink_to_fit();
            vis.arena.shrink_to_fit();
            generics.arena.shrink_to_fit();
@@ -296,7 +294,6 @@ struct ItemTreeData {
    macro_calls: Arena<MacroCall>,
    macro_rules: Arena<MacroRules>,
    macro_defs: Arena<MacroDef>,
-    exprs: Arena<Expr>,
    vis: ItemVisibilities,
    generics: GenericParamsStorage,
@@ -461,7 +458,7 @@ macro_rules! impl_index {
    };
 }
-impl_index!(fields: Field, variants: Variant, exprs: Expr);
+impl_index!(fields: Field, variants: Variant);
 impl Index<RawVisibilityId> for ItemTree {
    type Output = RawVisibility;
@@ -664,11 +661,6 @@ pub struct MacroDef {
    pub ast_id: FileAstId<ast::MacroDef>,
 }
-// NB: There's no `FileAstId` for `Expr`. The only case where this would be useful is for array
-// lengths, but we don't do much with them yet.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct Expr;
 macro_rules! impl_froms {
    ($e:ident { $($v:ident ($t:ty)),* $(,)? }) => {
        $(
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 3b206ef85..5e71ca42c 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -683,12 +683,12 @@ impl Ctx {
    }
    fn next_field_idx(&self) -> Idx<Field> {
-        Idx::from_raw(RawId::from(
+        Idx::from_raw(RawIdx::from(
            self.tree.data.as_ref().map_or(0, |data| data.fields.len() as u32),
        ))
    }
    fn next_variant_idx(&self) -> Idx<Variant> {
-        Idx::from_raw(RawId::from(
+        Idx::from_raw(RawIdx::from(
            self.tree.data.as_ref().map_or(0, |data| data.variants.len() as u32),
        ))
    }
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index 3dd7c3cbb..e34cd7f2f 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -87,7 +87,7 @@ impl ModPath {
    /// If this path is a single identifier, like `foo`, return its name.
    pub fn as_ident(&self) -> Option<&Name> {
-        if self.kind != PathKind::Plain || self.segments.len() > 1 {
+        if !self.is_ident() {
            return None;
        }
        self.segments.first()
diff --git a/crates/hir_def/src/src.rs b/crates/hir_def/src/src.rs
index eb29265d9..751d4c052 100644
--- a/crates/hir_def/src/src.rs
+++ b/crates/hir_def/src/src.rs
@@ -1,7 +1,7 @@
 //! Utilities for mapping between hir IDs and the surface syntax.
 use hir_expand::InFile;
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use crate::{db::DefDatabase, item_tree::ItemTreeNode, AssocItemLoc, ItemLoc};
diff --git a/crates/hir_def/src/trace.rs b/crates/hir_def/src/trace.rs
index 0a9beae8e..6e6ceb8e4 100644
--- a/crates/hir_def/src/trace.rs
+++ b/crates/hir_def/src/trace.rs
@@ -9,7 +9,7 @@
 //! absolute offsets. The `Trace` structure (inspired, at least in name, by
 //! Kotlin's `BindingTrace`) allows use the same code to compute both
 //! projections.
-use la_arena::{map::ArenaMap, Arena, Idx, RawId};
+use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 pub(crate) struct Trace<T, V> {
    arena: Option<Arena<T>>,
@@ -30,7 +30,7 @@ impl<T, V> Trace<T, V> {
        let id = if let Some(arena) = &mut self.arena {
            arena.alloc(data())
        } else {
-            let id = Idx::<T>::from_raw(RawId::from(self.len));
+            let id = Idx::<T>::from_raw(RawIdx::from(self.len));
            self.len += 1;
            id
        };
diff --git a/crates/hir_def/src/type_ref.rs b/crates/hir_def/src/type_ref.rs
index ae93d0d10..049b2e462 100644
--- a/crates/hir_def/src/type_ref.rs
+++ b/crates/hir_def/src/type_ref.rs
@@ -159,6 +159,8 @@ impl TypeRef {
            ast::Type::DynTraitType(inner) => {
                TypeRef::DynTrait(type_bounds_from_ast(ctx, inner.type_bound_list()))
            }
+            // FIXME: Macros in type position are not yet supported.
+            ast::Type::MacroType(_) => TypeRef::Error,
        }
    }
diff --git a/crates/hir_expand/Cargo.toml b/crates/hir_expand/Cargo.toml
index b535a3d4f..5271110d2 100644
--- a/crates/hir_expand/Cargo.toml
+++ b/crates/hir_expand/Cargo.toml
@@ -13,7 +13,7 @@ doctest = false
 log = "0.4.8"
 either = "1.5.3"
 rustc-hash = "1.0.0"
-la-arena = "0.1.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
 base_db = { path = "../base_db", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
diff --git a/crates/hir_expand/src/ast_id_map.rs b/crates/hir_expand/src/ast_id_map.rs
index f4f6e11fd..2401b0cc5 100644
--- a/crates/hir_expand/src/ast_id_map.rs
+++ b/crates/hir_expand/src/ast_id_map.rs
@@ -72,10 +72,12 @@ impl AstIdMap {
        // get lower ids then children. That is, adding a new child does not
        // change parent's id. This means that, say, adding a new function to a
        // trait does not change ids of top-level items, which helps caching.
-        bfs(node, |it| {
+        bdfs(node, |it| match ast::Item::cast(it) {
-            if let Some(module_item) = ast::Item::cast(it) {
+            Some(module_item) => {
                res.alloc(module_item.syntax());
+                true
            }
+            None => false,
        });
        res
    }
@@ -105,14 +107,30 @@ impl AstIdMap {
    }
 }
-/// Walks the subtree in bfs order, calling `f` for each node.
+/// Walks the subtree in bdfs order, calling `f` for each node. What is bdfs
-fn bfs(node: &SyntaxNode, mut f: impl FnMut(SyntaxNode)) {
+/// order? It is a mix of breadth-first and depth first orders. Nodes for which
+/// `f` returns true are visited breadth-first, all the other nodes are explored
+/// depth-first.
+///
+/// In other words, the size of the bfs queue is bound by the number of "true"
+/// nodes.
+fn bdfs(node: &SyntaxNode, mut f: impl FnMut(SyntaxNode) -> bool) {
    let mut curr_layer = vec![node.clone()];
    let mut next_layer = vec![];
    while !curr_layer.is_empty() {
        curr_layer.drain(..).for_each(|node| {
-            next_layer.extend(node.children());
+            let mut preorder = node.preorder();
-            f(node);
+            while let Some(event) = preorder.next() {
+                match event {
+                    syntax::WalkEvent::Enter(node) => {
+                        if f(node.clone()) {
+                            next_layer.extend(node.children());
+                            preorder.skip_subtree();
+                        }
+                    }
+                    syntax::WalkEvent::Leave(_) => {}
+                }
+            }
        });
        std::mem::swap(&mut curr_layer, &mut next_layer);
    }
diff --git a/crates/hir_expand/src/hygiene.rs b/crates/hir_expand/src/hygiene.rs
index 8db581b77..c8ea81210 100644
--- a/crates/hir_expand/src/hygiene.rs
+++ b/crates/hir_expand/src/hygiene.rs
@@ -76,6 +76,8 @@ pub struct HygieneFrame {
 impl HygieneFrames {
    fn new(db: &dyn AstDatabase, file_id: HirFileId) -> Self {
+        // Note that this intentionally avoids the `hygiene_frame` query to avoid blowing up memory
+        // usage. The query is only helpful for nested `HygieneFrame`s as it avoids redundant work.
        HygieneFrames(Arc::new(HygieneFrame::new(db, file_id)))
    }
diff --git a/crates/hir_expand/src/proc_macro.rs b/crates/hir_expand/src/proc_macro.rs
index 1923daca5..75e950816 100644
--- a/crates/hir_expand/src/proc_macro.rs
+++ b/crates/hir_expand/src/proc_macro.rs
@@ -135,7 +135,6 @@ mod tests {
        let result = format!("{:#?}", remove_derive_attrs(&tt).unwrap());
        assert_eq_text!(
-            &result,
            r#"
 SUBTREE $
  PUNCH   # [alone] 0
@@ -150,7 +149,8 @@ SUBTREE $
    PUNCH   : [alone] 19
    IDENT   u32 20
 "#
-            .trim()
+            .trim(),
+            &result
        );
    }
 }
diff --git a/crates/hir_ty/Cargo.toml b/crates/hir_ty/Cargo.toml
index 436c1405b..98434b741 100644
--- a/crates/hir_ty/Cargo.toml
+++ b/crates/hir_ty/Cargo.toml
@@ -20,7 +20,7 @@ scoped-tls = "1"
 chalk-solve = { version = "0.47", default-features = false }
 chalk-ir = "0.47"
 chalk-recursive = "0.47"
-la-arena = "0.1.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
 stdx = { path = "../stdx", version = "0.0.0" }
 hir_def = { path = "../hir_def", version = "0.0.0" }
diff --git a/crates/hir_ty/src/db.rs b/crates/hir_ty/src/db.rs
index b0e2a3b7d..b3af82444 100644
--- a/crates/hir_ty/src/db.rs
+++ b/crates/hir_ty/src/db.rs
@@ -7,7 +7,7 @@ use hir_def::{
    db::DefDatabase, expr::ExprId, ConstParamId, DefWithBodyId, FunctionId, GenericDefId, ImplId,
    LocalFieldId, TypeParamId, VariantId,
 };
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use crate::{
    method_resolution::{InherentImpls, TraitImpls},
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index 46a806b9a..d08867c70 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -30,7 +30,7 @@ use hir_def::{
    TypeAliasId, VariantId,
 };
 use hir_expand::{diagnostics::DiagnosticSink, name::name};
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use rustc_hash::FxHashMap;
 use stdx::impl_from;
 use syntax::SmolStr;
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 68d16f89a..7a734c8b9 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -20,7 +20,7 @@ use hir_def::{
    TypeAliasId, TypeParamId, UnionId, VariantId,
 };
 use hir_expand::name::Name;
-use la_arena::map::ArenaMap;
+use la_arena::ArenaMap;
 use smallvec::SmallVec;
 use stdx::impl_from;
 use test_utils::mark;
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index 3b1675f0b..5ff755321 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -26,7 +26,7 @@ use once_cell::race::OnceBool;
 use stdx::format_to;
 use syntax::{
    algo,
-    ast::{self, AstNode},
+    ast::{self, AstNode, NameOwner},
    SyntaxNode,
 };
 use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
@@ -153,7 +153,7 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
        });
        for (node, ty) in &types {
            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.value.clone()) {
-                (self_param.self_token().unwrap().text_range(), "self".to_string())
+                (self_param.name().unwrap().syntax().text_range(), "self".to_string())
            } else {
                (node.value.text_range(), node.value.text().to_string().replace("\n", " "))
            };
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index e4335119b..579d5a308 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -140,7 +140,7 @@ impl DiagnosticWithFix for IncorrectCase {
            rename_with_semantics(sema, file_position, &self.suggested_text).ok()?;
        let label = format!("Rename to {}", self.suggested_text);
-        Some(Fix::new(&label, rename_changes.info, rename_changes.range))
+        Some(Fix::new(&label, rename_changes, frange.range))
    }
 }
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index 685052e7f..00e601244 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -400,15 +400,13 @@ impl TryToNav for hir::GenericParam {
 impl ToNav for hir::Local {
    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
        let src = self.source(db);
-        let (node, focus_range) = match &src.value {
+        let (node, name) = match &src.value {
-            Either::Left(bind_pat) => (
+            Either::Left(bind_pat) => (bind_pat.syntax().clone(), bind_pat.name()),
-                bind_pat.syntax().clone(),
+            Either::Right(it) => (it.syntax().clone(), it.name()),
-                bind_pat
-                    .name()
-                    .map(|it| src.with_value(&it.syntax().clone()).original_file_range(db).range),
-            ),
-            Either::Right(it) => (it.syntax().clone(), it.self_token().map(|it| it.text_range())),
        };
+        let focus_range =
+            name.map(|it| src.with_value(&it.syntax().clone()).original_file_range(db).range);
        let full_range = src.with_value(&node).original_file_range(db);
        let name = match self.name(db) {
            Some(it) => it.to_string().into(),
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index 988a5668f..a1d2bce1d 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -55,11 +55,6 @@ pub(crate) fn goto_definition(
            } else {
                reference_definition(&sema, Either::Left(&lt)).to_vec()
            },
-            ast::SelfParam(self_param) => {
-                let def = NameClass::classify_self_param(&sema, &self_param)?.referenced_or_defined(sema.db);
-                let nav = def.try_to_nav(sema.db)?;
-                vec![nav]
-            },
            _ => return None,
        }
    };
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index 6022bd275..2024acd94 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -98,7 +98,6 @@ pub(crate) fn hover(
            ast::NameRef(name_ref) => NameRefClass::classify(&sema, &name_ref).map(|d| d.referenced(sema.db)),
            ast::Lifetime(lifetime) => NameClass::classify_lifetime(&sema, &lifetime)
                .map_or_else(|| NameRefClass::classify_lifetime(&sema, &lifetime).map(|d| d.referenced(sema.db)), |d| d.defined(sema.db)),
-            ast::SelfParam(self_param) => NameClass::classify_self_param(&sema, &self_param).and_then(|d| d.defined(sema.db)),
            _ => None,
        }
    };
@@ -3223,7 +3222,7 @@ impl Foo {
 }
 "#,
            expect![[r#"
-                *&self*
+                *self*
                ```rust
                &Foo
@@ -3243,7 +3242,7 @@ impl Foo {
 }
 "#,
            expect![[r#"
-                *self: Arc<Foo>*
+                *self*
                ```rust
                Arc<Foo>
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 07f52613f..3abbb14c6 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -86,18 +86,15 @@ pub use completion::{
    InsertTextFormat,
 };
 pub use hir::{Documentation, Semantics};
-pub use ide_db::base_db::{
-    Canceled, Change, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange, SourceRoot,
-    SourceRootId,
-};
 pub use ide_db::{
+    base_db::{
+        Canceled, Change, CrateGraph, CrateId, Edition, FileId, FilePosition, FileRange,
+        SourceRoot, SourceRootId,
+    },
    call_info::CallInfo,
-    search::{FileReference, ReferenceAccess, ReferenceKind},
-};
-pub use ide_db::{
    label::Label,
    line_index::{LineCol, LineIndex},
-    search::SearchScope,
+    search::{FileReference, ReferenceAccess, ReferenceKind, SearchScope},
    source_change::{FileSystemEdit, SourceChange},
    symbol_index::Query,
    RootDatabase,
@@ -525,7 +522,7 @@ impl Analysis {
        &self,
        position: FilePosition,
        new_name: &str,
-    ) -> Cancelable<Result<RangeInfo<SourceChange>, RenameError>> {
+    ) -> Cancelable<Result<SourceChange, RenameError>> {
        self.with_db(|db| references::rename::rename(db, position, new_name))
    }
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index 51a2f4327..df9c31aef 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -930,6 +930,26 @@ impl Foo {
        );
    }
+    #[test]
+    fn test_find_self_refs_decl() {
+        check(
+            r#"
+struct Foo { bar: i32 }
+impl Foo {
+    fn foo(self$0) {
+        self;
+    }
+}
+"#,
+            expect![[r#"
+                self SelfParam FileId(0) 47..51 47..51 SelfParam
+                FileId(0) 63..67 Other Read
+            "#]],
+        );
+    }
    fn check(ra_fixture: &str, expect: Expect) {
        check_with_scope(ra_fixture, None, expect)
    }
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index 9ac4af026..c25bcce50 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -1,27 +1,25 @@
 //! FIXME: write short doc here
-use std::{
+use std::fmt::{self, Display};
-    convert::TryInto,
-    fmt::{self, Display},
-};
-use hir::{Module, ModuleDef, ModuleSource, Semantics};
+use either::Either;
+use hir::{HasSource, InFile, Module, ModuleDef, ModuleSource, Semantics};
 use ide_db::{
-    base_db::{AnchoredPathBuf, FileId, FileRange, SourceDatabaseExt},
+    base_db::{AnchoredPathBuf, FileId, FileRange},
    defs::{Definition, NameClass, NameRefClass},
    search::FileReference,
    RootDatabase,
 };
+use stdx::assert_never;
 use syntax::{
-    algo::find_node_at_offset,
    ast::{self, NameOwner},
-    lex_single_syntax_kind, match_ast, AstNode, SyntaxKind, SyntaxNode, SyntaxToken, T,
+    lex_single_syntax_kind, AstNode, SyntaxKind, SyntaxNode, T,
 };
 use test_utils::mark;
 use text_edit::TextEdit;
 use crate::{
-    FilePosition, FileSystemEdit, RangeInfo, ReferenceKind, ReferenceSearchResult, SourceChange,
+    display::TryToNav, FilePosition, FileSystemEdit, RangeInfo, ReferenceKind, SourceChange,
-    TextRange, TextSize,
+    TextRange,
 };
 type RenameResult<T> = Result<T, RenameError>;
@@ -50,24 +48,22 @@ pub(crate) fn prepare_rename(
    let sema = Semantics::new(db);
    let source_file = sema.parse(position.file_id);
    let syntax = source_file.syntax();
-    if let Some(module) = find_module_at_offset(&sema, position, syntax) {
+    let range = match &find_name_like(&sema, &syntax, position)
-        rename_mod(&sema, position, module, "dummy")
+        .ok_or_else(|| format_err!("No references found at position"))?
-    } else if let Some(self_token) =
-        syntax.token_at_offset(position.offset).find(|t| t.kind() == T![self])
    {
-        rename_self_to_param(&sema, position, self_token, "dummy")
+        NameLike::Name(it) => it.syntax(),
-    } else {
+        NameLike::NameRef(it) => it.syntax(),
-        let RangeInfo { range, .. } = find_all_refs(&sema, position)?;
+        NameLike::Lifetime(it) => it.syntax(),
-        Ok(RangeInfo::new(range, SourceChange::default()))
    }
-    .map(|info| RangeInfo::new(info.range, ()))
+    .text_range();
+    Ok(RangeInfo::new(range, ()))
 }
 pub(crate) fn rename(
    db: &RootDatabase,
    position: FilePosition,
    new_name: &str,
-) -> RenameResult<RangeInfo<SourceChange>> {
+) -> RenameResult<SourceChange> {
    let sema = Semantics::new(db);
    rename_with_semantics(&sema, position, new_name)
 }
@@ -76,18 +72,15 @@ pub(crate) fn rename_with_semantics(
    sema: &Semantics<RootDatabase>,
    position: FilePosition,
    new_name: &str,
-) -> RenameResult<RangeInfo<SourceChange>> {
+) -> RenameResult<SourceChange> {
    let source_file = sema.parse(position.file_id);
    let syntax = source_file.syntax();
-    if let Some(module) = find_module_at_offset(&sema, position, syntax) {
+    let def = find_definition(sema, syntax, position)
-        rename_mod(&sema, position, module, new_name)
+        .ok_or_else(|| format_err!("No references found at position"))?;
-    } else if let Some(self_token) =
+    match def {
-        syntax.token_at_offset(position.offset).find(|t| t.kind() == T![self])
+        Definition::ModuleDef(ModuleDef::Module(module)) => rename_mod(&sema, module, new_name),
-    {
+        def => rename_reference(sema, def, new_name),
-        rename_self_to_param(&sema, position, self_token, new_name)
-    } else {
-        rename_reference(&sema, position, new_name)
    }
 }
@@ -98,17 +91,12 @@ pub(crate) fn will_rename_file(
 ) -> Option<SourceChange> {
    let sema = Semantics::new(db);
    let module = sema.to_module_def(file_id)?;
+    let mut change = rename_mod(&sema, module, new_name_stem).ok()?;
-    let decl = module.declaration_source(db)?;
-    let range = decl.value.name()?.syntax().text_range();
-    let position = FilePosition { file_id: decl.file_id.original_file(db), offset: range.start() };
-    let mut change = rename_mod(&sema, position, module, new_name_stem).ok()?.info;
    change.file_system_edits.clear();
    Some(change)
 }
-#[derive(Debug, PartialEq)]
+#[derive(Copy, Clone, Debug, PartialEq)]
 enum IdentifierKind {
    Ident,
    Lifetime,
@@ -135,40 +123,51 @@ fn check_identifier(new_name: &str) -> RenameResult<IdentifierKind> {
    }
 }
-fn find_module_at_offset(
+enum NameLike {
+    Name(ast::Name),
+    NameRef(ast::NameRef),
+    Lifetime(ast::Lifetime),
+}
+fn find_name_like(
    sema: &Semantics<RootDatabase>,
-    position: FilePosition,
    syntax: &SyntaxNode,
-) -> Option<Module> {
+    position: FilePosition,
-    let ident = syntax.token_at_offset(position.offset).find(|t| t.kind() == SyntaxKind::IDENT)?;
+) -> Option<NameLike> {
+    let namelike = if let Some(name_ref) =
-    let module = match_ast! {
+        sema.find_node_at_offset_with_descend::<ast::NameRef>(syntax, position.offset)
-        match (ident.parent()) {
+    {
-            ast::NameRef(name_ref) => {
+        NameLike::NameRef(name_ref)
-                match NameRefClass::classify(sema, &name_ref)? {
+    } else if let Some(name) =
-                    NameRefClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+        sema.find_node_at_offset_with_descend::<ast::Name>(syntax, position.offset)
-                    _ => return None,
+    {
-                }
+        NameLike::Name(name)
-            },
+    } else if let Some(lifetime) =
-            ast::Name(name) => {
+        sema.find_node_at_offset_with_descend::<ast::Lifetime>(syntax, position.offset)
-                match NameClass::classify(&sema, &name)? {
+    {
-                    NameClass::Definition(Definition::ModuleDef(ModuleDef::Module(module))) => module,
+        NameLike::Lifetime(lifetime)
-                    _ => return None,
+    } else {
-                }
+        return None;
-            },
-            _ => return None,
-        }
    };
+    Some(namelike)
-    Some(module)
 }
-fn find_all_refs(
+fn find_definition(
    sema: &Semantics<RootDatabase>,
+    syntax: &SyntaxNode,
    position: FilePosition,
-) -> RenameResult<RangeInfo<ReferenceSearchResult>> {
+) -> Option<Definition> {
-    crate::references::find_all_refs(sema, position, None)
+    let def = match find_name_like(sema, syntax, position)? {
-        .ok_or_else(|| format_err!("No references found at position"))
+        NameLike::Name(name) => NameClass::classify(sema, &name)?.referenced_or_defined(sema.db),
+        NameLike::NameRef(name_ref) => NameRefClass::classify(sema, &name_ref)?.referenced(sema.db),
+        NameLike::Lifetime(lifetime) => NameRefClass::classify_lifetime(sema, &lifetime)
+            .map(|class| NameRefClass::referenced(class, sema.db))
+            .or_else(|| {
+                NameClass::classify_lifetime(sema, &lifetime)
+                    .map(|it| it.referenced_or_defined(sema.db))
+            })?,
+    };
+    Some(def)
 }
 fn source_edit_from_references(
@@ -242,72 +241,84 @@ fn edit_text_range_for_record_field_expr_or_pat(
 fn rename_mod(
    sema: &Semantics<RootDatabase>,
-    position: FilePosition,
    module: Module,
    new_name: &str,
-) -> RenameResult<RangeInfo<SourceChange>> {
+) -> RenameResult<SourceChange> {
    if IdentifierKind::Ident != check_identifier(new_name)? {
        bail!("Invalid name `{0}`: cannot rename module to {0}", new_name);
    }
    let mut source_change = SourceChange::default();
-    let src = module.definition_source(sema.db);
+    let InFile { file_id, value: def_source } = module.definition_source(sema.db);
-    let file_id = src.file_id.original_file(sema.db);
+    let file_id = file_id.original_file(sema.db);
-    match src.value {
+    if let ModuleSource::SourceFile(..) = def_source {
-        ModuleSource::SourceFile(..) => {
+        // mod is defined in path/to/dir/mod.rs
-            // mod is defined in path/to/dir/mod.rs
+        let path = if module.is_mod_rs(sema.db) {
-            let path = if module.is_mod_rs(sema.db) {
+            format!("../{}/mod.rs", new_name)
-                format!("../{}/mod.rs", new_name)
+        } else {
-            } else {
+            format!("{}.rs", new_name)
-                format!("{}.rs", new_name)
+        };
-            };
+        let dst = AnchoredPathBuf { anchor: file_id, path };
-            let dst = AnchoredPathBuf { anchor: file_id, path };
+        let move_file = FileSystemEdit::MoveFile { src: file_id, dst };
-            let move_file = FileSystemEdit::MoveFile { src: file_id, dst };
+        source_change.push_file_system_edit(move_file);
-            source_change.push_file_system_edit(move_file);
+    }
-        }
-        ModuleSource::Module(..) => {}
+    if let Some(InFile { file_id, value: decl_source }) = module.declaration_source(sema.db) {
-    }
+        let file_id = file_id.original_file(sema.db);
+        match decl_source.name() {
-    if let Some(src) = module.declaration_source(sema.db) {
+            Some(name) => source_change.insert_source_edit(
-        let file_id = src.file_id.original_file(sema.db);
+                file_id,
-        let name = src.value.name().unwrap();
+                TextEdit::replace(name.syntax().text_range(), new_name.to_string()),
-        source_change.insert_source_edit(
+            ),
-            file_id,
+            _ => unreachable!(),
-            TextEdit::replace(name.syntax().text_range(), new_name.into()),
+        };
-        );
    }
+    let def = Definition::ModuleDef(ModuleDef::Module(module));
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
+    let usages = def.usages(sema).all();
-    let ref_edits = refs.references().iter().map(|(&file_id, references)| {
+    let ref_edits = usages.iter().map(|(&file_id, references)| {
        source_edit_from_references(sema, file_id, references, new_name)
    });
    source_change.extend(ref_edits);
-    Ok(RangeInfo::new(range, source_change))
+    Ok(source_change)
 }
-fn rename_to_self(
+fn rename_to_self(sema: &Semantics<RootDatabase>, local: hir::Local) -> RenameResult<SourceChange> {
-    sema: &Semantics<RootDatabase>,
+    if assert_never!(local.is_self(sema.db)) {
-    position: FilePosition,
+        bail!("rename_to_self invoked on self");
-) -> Result<RangeInfo<SourceChange>, RenameError> {
+    }
-    let source_file = sema.parse(position.file_id);
-    let syn = source_file.syntax();
+    let fn_def = match local.parent(sema.db) {
+        hir::DefWithBody::Function(func) => func,
+        _ => bail!("Cannot rename non-param local to self"),
+    };
+    // FIXME: reimplement this on the hir instead
+    // as of the time of this writing params in hir don't keep their names
+    let fn_ast =
+        fn_def.source(sema.db).ok_or(format_err!("Cannot rename non-param local to self"))?.value;
-    let (fn_def, fn_ast) = find_node_at_offset::<ast::Fn>(syn, position.offset)
+    let first_param_range = fn_ast
-        .and_then(|fn_ast| sema.to_def(&fn_ast).zip(Some(fn_ast)))
-        .ok_or_else(|| format_err!("No surrounding method declaration found"))?;
-    let param_range = fn_ast
        .param_list()
        .and_then(|p| p.params().next())
        .ok_or_else(|| format_err!("Method has no parameters"))?
        .syntax()
        .text_range();
-    if !param_range.contains(position.offset) {
+    let InFile { file_id, value: local_source } = local.source(sema.db);
-        bail!("Only the first parameter can be self");
+    match local_source {
+        either::Either::Left(pat)
+            if !first_param_range.contains_range(pat.syntax().text_range()) =>
+        {
+            bail!("Only the first parameter can be self");
+        }
+        _ => (),
    }
-    let impl_block = find_node_at_offset::<ast::Impl>(syn, position.offset)
+    let impl_block = fn_ast
+        .syntax()
+        .ancestors()
+        .find_map(|node| ast::Impl::cast(node))
        .and_then(|def| sema.to_def(&def))
        .ok_or_else(|| format_err!("No impl block found for function"))?;
    if fn_def.self_param(sema.db).is_some() {
@@ -331,25 +342,21 @@ fn rename_to_self(
        bail!("Parameter type differs from impl block type");
    }
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
+    let def = Definition::Local(local);
+    let usages = def.usages(sema).all();
    let mut source_change = SourceChange::default();
-    source_change.extend(refs.references().iter().map(|(&file_id, references)| {
+    source_change.extend(usages.iter().map(|(&file_id, references)| {
        source_edit_from_references(sema, file_id, references, "self")
    }));
    source_change.insert_source_edit(
-        position.file_id,
+        file_id.original_file(sema.db),
-        TextEdit::replace(param_range, String::from(self_param)),
+        TextEdit::replace(first_param_range, String::from(self_param)),
    );
-    Ok(RangeInfo::new(range, source_change))
+    Ok(source_change)
 }
-fn text_edit_from_self_param(
+fn text_edit_from_self_param(self_param: &ast::SelfParam, new_name: &str) -> Option<TextEdit> {
-    syn: &SyntaxNode,
-    self_param: &ast::SelfParam,
-    new_name: &str,
-) -> Option<TextEdit> {
    fn target_type_name(impl_def: &ast::Impl) -> Option<String> {
        if let Some(ast::Type::PathType(p)) = impl_def.self_ty() {
            return Some(p.path()?.segment()?.name_ref()?.text().to_string());
@@ -357,7 +364,7 @@ fn text_edit_from_self_param(
        None
    }
-    let impl_def = find_node_at_offset::<ast::Impl>(syn, self_param.syntax().text_range().start())?;
+    let impl_def = self_param.syntax().ancestors().find_map(|it| ast::Impl::cast(it))?;
    let type_name = target_type_name(&impl_def)?;
    let mut replacement_text = String::from(new_name);
@@ -374,96 +381,119 @@ fn text_edit_from_self_param(
 fn rename_self_to_param(
    sema: &Semantics<RootDatabase>,
-    position: FilePosition,
+    local: hir::Local,
-    self_token: SyntaxToken,
    new_name: &str,
-) -> Result<RangeInfo<SourceChange>, RenameError> {
+    identifier_kind: IdentifierKind,
-    let ident_kind = check_identifier(new_name)?;
+) -> RenameResult<SourceChange> {
-    match ident_kind {
+    let (file_id, self_param) = match local.source(sema.db) {
-        IdentifierKind::Lifetime => bail!("Invalid name `{}`: not an identifier", new_name),
+        InFile { file_id, value: Either::Right(self_param) } => (file_id, self_param),
-        IdentifierKind::ToSelf => {
+        _ => {
-            // no-op
+            assert_never!(true, "rename_self_to_param invoked on a non-self local");
-            mark::hit!(rename_self_to_self);
+            bail!("rename_self_to_param invoked on a non-self local");
-            return Ok(RangeInfo::new(self_token.text_range(), SourceChange::default()));
-        }
-        _ => (),
-    }
-    let source_file = sema.parse(position.file_id);
-    let syn = source_file.syntax();
-    let text = sema.db.file_text(position.file_id);
-    let fn_def = find_node_at_offset::<ast::Fn>(syn, position.offset)
-        .ok_or_else(|| format_err!("No surrounding method declaration found"))?;
-    let search_range = fn_def.syntax().text_range();
-    let mut source_change = SourceChange::default();
-    for (idx, _) in text.match_indices("self") {
-        let offset: TextSize = idx.try_into().unwrap();
-        if !search_range.contains_inclusive(offset) {
-            continue;
        }
-        if let Some(ref usage) = syn.token_at_offset(offset).find(|t| t.kind() == T![self]) {
+    };
-            let edit = if let Some(ref self_param) = ast::SelfParam::cast(usage.parent()) {
-                text_edit_from_self_param(syn, self_param, new_name)
-                    .ok_or_else(|| format_err!("No target type found"))?
-            } else {
-                TextEdit::replace(usage.text_range(), String::from(new_name))
-            };
-            source_change.insert_source_edit(position.file_id, edit);
-        }
-    }
-    if source_change.source_file_edits.len() > 1 && ident_kind == IdentifierKind::Underscore {
+    let def = Definition::Local(local);
+    let usages = def.usages(sema).all();
+    let edit = text_edit_from_self_param(&self_param, new_name)
+        .ok_or_else(|| format_err!("No target type found"))?;
+    if usages.len() > 1 && identifier_kind == IdentifierKind::Underscore {
        bail!("Cannot rename reference to `_` as it is being referenced multiple times");
    }
+    let mut source_change = SourceChange::default();
-    let range = ast::SelfParam::cast(self_token.parent())
+    source_change.insert_source_edit(file_id.original_file(sema.db), edit);
-        .map_or(self_token.text_range(), |p| p.syntax().text_range());
+    source_change.extend(usages.iter().map(|(&file_id, references)| {
+        source_edit_from_references(sema, file_id, &references, new_name)
-    Ok(RangeInfo::new(range, source_change))
+    }));
+    Ok(source_change)
 }
 fn rename_reference(
    sema: &Semantics<RootDatabase>,
-    position: FilePosition,
+    def: Definition,
    new_name: &str,
-) -> Result<RangeInfo<SourceChange>, RenameError> {
+) -> RenameResult<SourceChange> {
    let ident_kind = check_identifier(new_name)?;
-    let RangeInfo { range, info: refs } = find_all_refs(sema, position)?;
-    match (ident_kind, &refs.declaration.kind) {
+    let def_is_lbl_or_lt = matches!(def,
-        (IdentifierKind::ToSelf, ReferenceKind::Lifetime)
+        Definition::GenericParam(hir::GenericParam::LifetimeParam(_))
-        | (IdentifierKind::Underscore, ReferenceKind::Lifetime)
+        | Definition::Label(_)
-        | (IdentifierKind::Ident, ReferenceKind::Lifetime) => {
+    );
+    match (ident_kind, def) {
+        (IdentifierKind::ToSelf, _)
+        | (IdentifierKind::Underscore, _)
+        | (IdentifierKind::Ident, _)
+            if def_is_lbl_or_lt =>
+        {
            mark::hit!(rename_not_a_lifetime_ident_ref);
            bail!("Invalid name `{}`: not a lifetime identifier", new_name)
        }
-        (IdentifierKind::Lifetime, ReferenceKind::Lifetime) => mark::hit!(rename_lifetime),
+        (IdentifierKind::Lifetime, _) if def_is_lbl_or_lt => mark::hit!(rename_lifetime),
        (IdentifierKind::Lifetime, _) => {
            mark::hit!(rename_not_an_ident_ref);
            bail!("Invalid name `{}`: not an identifier", new_name)
        }
-        (IdentifierKind::ToSelf, ReferenceKind::SelfParam) => {
+        (IdentifierKind::ToSelf, Definition::Local(local)) if local.is_self(sema.db) => {
-            unreachable!("rename_self_to_param should've been called instead")
+            // no-op
+            mark::hit!(rename_self_to_self);
+            return Ok(SourceChange::default());
        }
-        (IdentifierKind::ToSelf, _) => {
+        (ident_kind, Definition::Local(local)) if local.is_self(sema.db) => {
-            mark::hit!(rename_to_self);
+            mark::hit!(rename_self_to_param);
-            return rename_to_self(sema, position);
+            return rename_self_to_param(sema, local, new_name, ident_kind);
        }
-        (IdentifierKind::Underscore, _) if !refs.references.is_empty() => {
+        (IdentifierKind::ToSelf, Definition::Local(local)) => {
-            mark::hit!(rename_underscore_multiple);
+            mark::hit!(rename_to_self);
-            bail!("Cannot rename reference to `_` as it is being referenced multiple times")
+            return rename_to_self(sema, local);
        }
+        (IdentifierKind::ToSelf, _) => bail!("Invalid name `{}`: not an identifier", new_name),
        (IdentifierKind::Ident, _) | (IdentifierKind::Underscore, _) => mark::hit!(rename_ident),
    }
+    let usages = def.usages(sema).all();
+    if !usages.is_empty() && ident_kind == IdentifierKind::Underscore {
+        mark::hit!(rename_underscore_multiple);
+        bail!("Cannot rename reference to `_` as it is being referenced multiple times");
+    }
    let mut source_change = SourceChange::default();
-    source_change.extend(refs.into_iter().map(|(file_id, references)| {
+    source_change.extend(usages.iter().map(|(&file_id, references)| {
        source_edit_from_references(sema, file_id, &references, new_name)
    }));
-    Ok(RangeInfo::new(range, source_change))
+    let (file_id, edit) = source_edit_from_def(sema, def, new_name)?;
+    source_change.insert_source_edit(file_id, edit);
+    Ok(source_change)
+}
+fn source_edit_from_def(
+    sema: &Semantics<RootDatabase>,
+    def: Definition,
+    new_name: &str,
+) -> RenameResult<(FileId, TextEdit)> {
+    let nav = def.try_to_nav(sema.db).unwrap();
+    let mut replacement_text = String::new();
+    let mut repl_range = nav.focus_or_full_range();
+    if let Definition::Local(local) = def {
+        if let Either::Left(pat) = local.source(sema.db).value {
+            if matches!(
+                pat.syntax().parent().and_then(ast::RecordPatField::cast),
+                Some(pat_field) if pat_field.name_ref().is_none()
+            ) {
+                replacement_text.push_str(": ");
+                replacement_text.push_str(new_name);
+                repl_range = TextRange::new(
+                    pat.syntax().text_range().end(),
+                    pat.syntax().text_range().end(),
+                );
+            }
+        }
+    }
+    if replacement_text.is_empty() {
+        replacement_text.push_str(new_name);
+    }
+    let edit = TextEdit::replace(repl_range, replacement_text);
+    Ok((nav.file_id, edit))
 }
 #[cfg(test)]
@@ -485,7 +515,7 @@ mod tests {
            Ok(source_change) => {
                let mut text_edit_builder = TextEdit::builder();
                let mut file_id: Option<FileId> = None;
-                for edit in source_change.info.source_file_edits {
+                for edit in source_change.source_file_edits {
                    file_id = Some(edit.0);
                    for indel in edit.1.into_iter() {
                        text_edit_builder.replace(indel.delete, indel.insert);
@@ -884,36 +914,33 @@ mod foo$0;
 // empty
 "#,
            expect![[r#"
-                RangeInfo {
+                SourceChange {
-                    range: 4..7,
+                    source_file_edits: {
-                    info: SourceChange {
+                        FileId(
-                        source_file_edits: {
+                            1,
-                            FileId(
+                        ): TextEdit {
-                                1,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "foo2",
-                                    Indel {
+                                    delete: 4..7,
-                                        insert: "foo2",
+                                },
-                                        delete: 4..7,
+                            ],
-                                    },
-                                ],
-                            },
                        },
-                        file_system_edits: [
+                    },
-                            MoveFile {
+                    file_system_edits: [
-                                src: FileId(
+                        MoveFile {
+                            src: FileId(
+                                2,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
                                    2,
                                ),
-                                dst: AnchoredPathBuf {
+                                path: "foo2.rs",
-                                    anchor: FileId(
-                                        2,
-                                    ),
-                                    path: "foo2.rs",
-                                },
                            },
-                        ],
+                        },
-                        is_snippet: false,
+                    ],
-                    },
+                    is_snippet: false,
                }
            "#]],
        );
@@ -936,46 +963,43 @@ pub struct FooContent;
 use crate::foo$0::FooContent;
 "#,
            expect![[r#"
-                RangeInfo {
+                SourceChange {
-                    range: 11..14,
+                    source_file_edits: {
-                    info: SourceChange {
+                        FileId(
-                        source_file_edits: {
+                            0,
-                            FileId(
+                        ): TextEdit {
-                                0,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "quux",
-                                    Indel {
+                                    delete: 8..11,
-                                        insert: "quux",
+                                },
-                                        delete: 8..11,
+                            ],
-                                    },
+                        },
-                                ],
+                        FileId(
-                            },
+                            2,
-                            FileId(
+                        ): TextEdit {
-                                2,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "quux",
-                                    Indel {
+                                    delete: 11..14,
-                                        insert: "quux",
+                                },
-                                        delete: 11..14,
+                            ],
-                                    },
-                                ],
-                            },
                        },
-                        file_system_edits: [
+                    },
-                            MoveFile {
+                    file_system_edits: [
-                                src: FileId(
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
                                    1,
                                ),
-                                dst: AnchoredPathBuf {
+                                path: "quux.rs",
-                                    anchor: FileId(
-                                        1,
-                                    ),
-                                    path: "quux.rs",
-                                },
                            },
-                        ],
+                        },
-                        is_snippet: false,
+                    ],
-                    },
+                    is_snippet: false,
                }
            "#]],
        );
@@ -992,36 +1016,33 @@ mod fo$0o;
 // empty
 "#,
            expect![[r#"
-                RangeInfo {
+                SourceChange {
-                    range: 4..7,
+                    source_file_edits: {
-                    info: SourceChange {
+                        FileId(
-                        source_file_edits: {
+                            0,
-                            FileId(
+                        ): TextEdit {
-                                0,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "foo2",
-                                    Indel {
+                                    delete: 4..7,
-                                        insert: "foo2",
+                                },
-                                        delete: 4..7,
+                            ],
-                                    },
-                                ],
-                            },
                        },
-                        file_system_edits: [
+                    },
-                            MoveFile {
+                    file_system_edits: [
-                                src: FileId(
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
                                    1,
                                ),
-                                dst: AnchoredPathBuf {
+                                path: "../foo2/mod.rs",
-                                    anchor: FileId(
-                                        1,
-                                    ),
-                                    path: "../foo2/mod.rs",
-                                },
                            },
-                        ],
+                        },
-                        is_snippet: false,
+                    ],
-                    },
+                    is_snippet: false,
                }
            "#]],
        );
@@ -1039,36 +1060,33 @@ mod outer { mod fo$0o; }
 // empty
 "#,
            expect![[r#"
-                RangeInfo {
+                SourceChange {
-                    range: 16..19,
+                    source_file_edits: {
-                    info: SourceChange {
+                        FileId(
-                        source_file_edits: {
+                            0,
-                            FileId(
+                        ): TextEdit {
-                                0,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "bar",
-                                    Indel {
+                                    delete: 16..19,
-                                        insert: "bar",
+                                },
-                                        delete: 16..19,
+                            ],
-                                    },
-                                ],
-                            },
                        },
-                        file_system_edits: [
+                    },
-                            MoveFile {
+                    file_system_edits: [
-                                src: FileId(
+                        MoveFile {
+                            src: FileId(
+                                1,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
                                    1,
                                ),
-                                dst: AnchoredPathBuf {
+                                path: "bar.rs",
-                                    anchor: FileId(
-                                        1,
-                                    ),
-                                    path: "bar.rs",
-                                },
                            },
-                        ],
+                        },
-                        is_snippet: false,
+                    ],
-                    },
+                    is_snippet: false,
                }
            "#]],
        );
@@ -1109,46 +1127,43 @@ pub mod foo$0;
 // pub fn fun() {}
 "#,
            expect![[r#"
-                RangeInfo {
+                SourceChange {
-                    range: 8..11,
+                    source_file_edits: {
-                    info: SourceChange {
+                        FileId(
-                        source_file_edits: {
+                            0,
-                            FileId(
+                        ): TextEdit {
-                                0,
+                            indels: [
-                            ): TextEdit {
+                                Indel {
-                                indels: [
+                                    insert: "foo2",
-                                    Indel {
+                                    delete: 27..30,
-                                        insert: "foo2",
+                                },
-                                        delete: 27..30,
+                            ],
-                                    },
-                                ],
-                            },
-                            FileId(
-                                1,
-                            ): TextEdit {
-                                indels: [
-                                    Indel {
-                                        insert: "foo2",
-                                        delete: 8..11,
-                                    },
-                                ],
-                            },
                        },
-                        file_system_edits: [
+                        FileId(
-                            MoveFile {
+                            1,
-                                src: FileId(
+                        ): TextEdit {
+                            indels: [
+                                Indel {
+                                    insert: "foo2",
+                                    delete: 8..11,
+                                },
+                            ],
+                        },
+                    },
+                    file_system_edits: [
+                        MoveFile {
+                            src: FileId(
+                                2,
+                            ),
+                            dst: AnchoredPathBuf {
+                                anchor: FileId(
                                    2,
                                ),
-                                dst: AnchoredPathBuf {
+                                path: "foo2.rs",
-                                    anchor: FileId(
-                                        2,
-                                    ),
-                                    path: "foo2.rs",
-                                },
                            },
-                        ],
+                        },
-                        is_snippet: false,
+                    ],
-                    },
+                    is_snippet: false,
                }
            "#]],
        );
@@ -1350,6 +1365,7 @@ impl Foo {
    #[test]
    fn test_owned_self_to_parameter() {
+        mark::check!(rename_self_to_param);
        check(
            "foo",
            r#"
diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 87578e70a..8625ef5df 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -68,7 +68,8 @@ pub(super) fn element(
        NAME_REF => {
            let name_ref = element.into_node().and_then(ast::NameRef::cast).unwrap();
            highlight_func_by_name_ref(sema, &name_ref).unwrap_or_else(|| {
-                match NameRefClass::classify(sema, &name_ref) {
+                let is_self = name_ref.self_token().is_some();
+                let h = match NameRefClass::classify(sema, &name_ref) {
                    Some(name_kind) => match name_kind {
                        NameRefClass::ExternCrate(_) => HlTag::Symbol(SymbolKind::Module).into(),
                        NameRefClass::Definition(def) => {
@@ -108,6 +109,11 @@ pub(super) fn element(
                        highlight_name_ref_by_syntax(name_ref, sema)
                    }
                    None => HlTag::UnresolvedReference.into(),
+                };
+                if h.tag == HlTag::Symbol(SymbolKind::Module) && is_self {
+                    HlTag::Symbol(SymbolKind::SelfParam).into()
+                } else {
+                    h
                }
            })
        }
@@ -225,18 +231,8 @@ pub(super) fn element(
                T![for] if !is_child_of_impl(&element) => h | HlMod::ControlFlow,
                T![unsafe] => h | HlMod::Unsafe,
                T![true] | T![false] => HlTag::BoolLiteral.into(),
-                T![self] => {
+                // self is handled as either a Name or NameRef already
-                    let self_param = element.parent().and_then(ast::SelfParam::cast);
+                T![self] => return None,
-                    if let Some(NameClass::Definition(def)) = self_param
-                        .and_then(|self_param| NameClass::classify_self_param(sema, &self_param))
-                    {
-                        highlight_def(db, def) | HlMod::Definition
-                    } else if element.ancestors().any(|it| it.kind() == USE_TREE) {
-                        HlTag::Symbol(SymbolKind::SelfParam).into()
-                    } else {
-                        return None;
-                    }
-                }
                T![ref] => element
                    .parent()
                    .and_then(ast::IdentPat::cast)
diff --git a/crates/ide/src/syntax_tree.rs b/crates/ide/src/syntax_tree.rs
index 1d4bac7ad..4c63d3023 100644
--- a/crates/ide/src/syntax_tree.rs
+++ b/crates/ide/src/syntax_tree.rs
@@ -111,7 +111,6 @@ mod tests {
        let syn = analysis.syntax_tree(file_id, None).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -127,7 +126,8 @@ [email protected]
      [email protected] "{"
      [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
        let (analysis, file_id) = fixture::file(
@@ -143,7 +143,6 @@ fn test() {
        let syn = analysis.syntax_tree(file_id, None).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -176,7 +175,8 @@ [email protected]
      [email protected] "\n"
      [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
    }
@@ -186,7 +186,6 @@ [email protected]
        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected] "fn"
@@ -201,7 +200,8 @@ [email protected]
    [email protected] "{"
    [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
        let (analysis, range) = fixture::range(
@@ -216,7 +216,6 @@ [email protected]
        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -234,7 +233,8 @@ [email protected]
      [email protected] ")"
  [email protected] ";"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
    }
@@ -253,7 +253,6 @@ fn bar() {
        );
        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -270,7 +269,8 @@ [email protected]
      [email protected] "\n"
      [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
        // With a raw string
@@ -287,7 +287,6 @@ fn bar() {
        );
        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -304,7 +303,8 @@ [email protected]
      [email protected] "\n"
      [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
        // With a raw string
@@ -320,7 +320,6 @@ fn bar() {
        );
        let syn = analysis.syntax_tree(range.file_id, Some(range.range)).unwrap();
        assert_eq_text!(
-            syn.trim(),
            r#"
 [email protected]
  [email protected]
@@ -351,7 +350,8 @@ [email protected]
      [email protected] "\n"
      [email protected] "}"
 "#
-            .trim()
+            .trim(),
+            syn.trim()
        );
    }
 }
diff --git a/crates/ide_db/src/defs.rs b/crates/ide_db/src/defs.rs
index 231e886a9..d9875ffef 100644
--- a/crates/ide_db/src/defs.rs
+++ b/crates/ide_db/src/defs.rs
@@ -117,13 +117,6 @@ impl NameClass {
        }
    }
-    pub fn classify_self_param(
-        sema: &Semantics<RootDatabase>,
-        self_param: &ast::SelfParam,
-    ) -> Option<NameClass> {
-        sema.to_def(self_param).map(Definition::Local).map(NameClass::Definition)
-    }
    pub fn classify(sema: &Semantics<RootDatabase>, name: &ast::Name) -> Option<NameClass> {
        let _p = profile::span("classify_name");
@@ -186,6 +179,10 @@ impl NameClass {
                    Some(NameClass::Definition(Definition::Local(local)))
                },
+                ast::SelfParam(it) => {
+                    let def = sema.to_def(&it)?;
+                    Some(NameClass::Definition(Definition::Local(def.into())))
+                },
                ast::RecordField(it) => {
                    let field: hir::Field = sema.to_def(&it)?;
                    Some(NameClass::Definition(Definition::Field(field)))
diff --git a/crates/ide_db/src/helpers/insert_use/tests.rs b/crates/ide_db/src/helpers/insert_use/tests.rs
index a603fe87f..4bbe66f1f 100644
--- a/crates/ide_db/src/helpers/insert_use/tests.rs
+++ b/crates/ide_db/src/helpers/insert_use/tests.rs
@@ -599,7 +599,7 @@ fn check(
    let rewriter = insert_use(&file, path, mb);
    let result = rewriter.rewrite(file.as_syntax_node()).to_string();
-    assert_eq_text!(&result, ra_fixture_after);
+    assert_eq_text!(ra_fixture_after, &result);
 }
 fn check_full(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
diff --git a/crates/mbe/src/syntax_bridge.rs b/crates/mbe/src/syntax_bridge.rs
index e648519f9..2a41d8167 100644
--- a/crates/mbe/src/syntax_bridge.rs
+++ b/crates/mbe/src/syntax_bridge.rs
@@ -51,6 +51,7 @@ pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> Option<(tt::Subtree, Toke
    let global_offset = node.text_range().start();
    let mut c = Convertor::new(node, global_offset);
    let subtree = c.go()?;
+    c.id_alloc.map.entries.shrink_to_fit();
    Some((subtree, c.id_alloc.map))
 }
@@ -593,7 +594,8 @@ impl<'a> TtTreeSink<'a> {
        }
    }
-    fn finish(self) -> (Parse<SyntaxNode>, TokenMap) {
+    fn finish(mut self) -> (Parse<SyntaxNode>, TokenMap) {
+        self.token_map.entries.shrink_to_fit();
        (self.inner.finish(), self.token_map)
    }
 }
diff --git a/crates/mbe/src/tests.rs b/crates/mbe/src/tests.rs
index 9ff901e97..bd2977ebd 100644
--- a/crates/mbe/src/tests.rs
+++ b/crates/mbe/src/tests.rs
@@ -261,7 +261,6 @@ fn test_expr_order() {
    let dump = format!("{:#?}", expanded);
    assert_eq_text!(
-        dump.trim(),
        r#"[email protected]
  [email protected]
    [email protected] "fn"
@@ -285,6 +284,7 @@ fn test_expr_order() {
            [email protected] "2"
        [email protected] ";"
      [email protected] "}""#,
+        dump.trim()
    );
 }
@@ -989,7 +989,6 @@ fn test_tt_composite2() {
    let res = format!("{:#?}", &node);
    assert_eq_text!(
-        res.trim(),
        r###"[email protected]
  [email protected]
    [email protected]
@@ -1003,7 +1002,8 @@ fn test_tt_composite2() {
      [email protected] ">"
      [email protected] " "
      [email protected] "#"
-      [email protected] ")""###
+      [email protected] ")""###,
+        res.trim()
    );
 }
@@ -1742,7 +1742,7 @@ impl MacroFixture {
    fn assert_expand(&self, invocation: &str, expected: &str) {
        let expansion = self.expand_tt(invocation);
        let actual = format!("{:?}", expansion);
-        test_utils::assert_eq_text!(&actual.trim(), &expected.trim());
+        test_utils::assert_eq_text!(&expected.trim(), &actual.trim());
    }
    fn assert_expand_items(&self, invocation: &str, expected: &str) -> &MacroFixture {
@@ -1941,7 +1941,6 @@ fn test_no_space_after_semi_colon() {
    let dump = format!("{:#?}", expanded);
    assert_eq_text!(
-        dump.trim(),
        r###"[email protected]
  [email protected]
    [email protected]
@@ -1981,6 +1980,7 @@ fn test_no_space_after_semi_colon() {
    [email protected]
      [email protected] "f"
    [email protected] ";""###,
+        dump.trim()
    );
 }
diff --git a/crates/parser/src/grammar.rs b/crates/parser/src/grammar.rs
index bb9ffea8b..6913e9ec2 100644
--- a/crates/parser/src/grammar.rs
+++ b/crates/parser/src/grammar.rs
@@ -190,17 +190,25 @@ fn opt_visibility(p: &mut Parser) -> bool {
                    // test crate_visibility
                    // pub(crate) struct S;
                    // pub(self) struct S;
-                    // pub(self) struct S;
+                    // pub(super) struct S;
-                    // pub(self) struct S;
                    // test pub_parens_typepath
                    // struct B(pub (super::A));
                    // struct B(pub (crate::A,));
                    T![crate] | T![self] | T![super] if p.nth(2) != T![:] => {
                        p.bump_any();
+                        let path_m = p.start();
+                        let path_segment_m = p.start();
+                        let name_ref_m = p.start();
                        p.bump_any();
+                        name_ref_m.complete(p, NAME_REF);
+                        path_segment_m.complete(p, PATH_SEGMENT);
+                        path_m.complete(p, PATH);
                        p.expect(T![')']);
                    }
+                    // test crate_visibility_in
+                    // pub(in super::A) struct S;
+                    // pub(in crate) struct S;
                    T![in] => {
                        p.bump_any();
                        p.bump_any();
diff --git a/crates/parser/src/grammar/items.rs b/crates/parser/src/grammar/items.rs
index 2070ce163..1d894e907 100644
--- a/crates/parser/src/grammar/items.rs
+++ b/crates/parser/src/grammar/items.rs
@@ -270,7 +270,9 @@ fn extern_crate(p: &mut Parser, m: Marker) {
    p.bump(T![crate]);
    if p.at(T![self]) {
+        let m = p.start();
        p.bump(T![self]);
+        m.complete(p, NAME_REF);
    } else {
        name_ref(p);
    }
diff --git a/crates/parser/src/grammar/items/traits.rs b/crates/parser/src/grammar/items/traits.rs
index d076974ed..d3327271c 100644
--- a/crates/parser/src/grammar/items/traits.rs
+++ b/crates/parser/src/grammar/items/traits.rs
@@ -40,6 +40,10 @@ pub(super) fn impl_(p: &mut Parser) {
        type_params::opt_generic_param_list(p);
    }
+    // test impl_def_const
+    // impl const Send for X {}
+    p.eat(T![const]);
    // FIXME: never type
    // impl ! {}
diff --git a/crates/parser/src/grammar/params.rs b/crates/parser/src/grammar/params.rs
index 2d006a1d5..6a98d7368 100644
--- a/crates/parser/src/grammar/params.rs
+++ b/crates/parser/src/grammar/params.rs
@@ -156,7 +156,7 @@ fn variadic_param(p: &mut Parser) -> bool {
 fn opt_self_param(p: &mut Parser, m: Marker) {
    if p.at(T![self]) || p.at(T![mut]) && p.nth(1) == T![self] {
        p.eat(T![mut]);
-        p.eat(T![self]);
+        self_as_name(p);
        // test arb_self_types
        // impl S {
        //     fn a(self: &Self) {}
@@ -169,24 +169,29 @@ fn opt_self_param(p: &mut Parser, m: Marker) {
        let la1 = p.nth(1);
        let la2 = p.nth(2);
        let la3 = p.nth(3);
-        let mut n_toks = match (p.current(), la1, la2, la3) {
+        if !matches!((p.current(), la1, la2, la3),
-            (T![&], T![self], _, _) => 2,
+              (T![&], T![self], _, _)
-            (T![&], T![mut], T![self], _) => 3,
+            | (T![&], T![mut], T![self], _)
-            (T![&], LIFETIME_IDENT, T![self], _) => 3,
+            | (T![&], LIFETIME_IDENT, T![self], _)
-            (T![&], LIFETIME_IDENT, T![mut], T![self]) => 4,
+            | (T![&], LIFETIME_IDENT, T![mut], T![self])
-            _ => return m.abandon(p),
+        ) {
-        };
+            return m.abandon(p);
-        p.bump_any();
+        }
+        p.bump(T![&]);
        if p.at(LIFETIME_IDENT) {
            lifetime(p);
-            n_toks -= 1;
-        }
-        for _ in 1..n_toks {
-            p.bump_any();
        }
+        p.eat(T![mut]);
+        self_as_name(p);
    }
    m.complete(p, SELF_PARAM);
    if !p.at(T![')']) {
        p.expect(T![,]);
    }
 }
+fn self_as_name(p: &mut Parser) {
+    let m = p.start();
+    p.bump(T![self]);
+    m.complete(p, NAME);
+}
diff --git a/crates/parser/src/syntax_kind.rs b/crates/parser/src/syntax_kind.rs
index 63204436c..9ea0e4f9b 100644
--- a/crates/parser/src/syntax_kind.rs
+++ b/crates/parser/src/syntax_kind.rs
@@ -6,6 +6,7 @@ mod generated;
 pub use self::generated::SyntaxKind;
 impl From<u16> for SyntaxKind {
+    #[inline]
    fn from(d: u16) -> SyntaxKind {
        assert!(d <= (SyntaxKind::__LAST as u16));
        unsafe { std::mem::transmute::<u16, SyntaxKind>(d) }
@@ -13,12 +14,14 @@ impl From<u16> for SyntaxKind {
 }
 impl From<SyntaxKind> for u16 {
+    #[inline]
    fn from(k: SyntaxKind) -> u16 {
        k as u16
    }
 }
 impl SyntaxKind {
+    #[inline]
    pub fn is_trivia(self) -> bool {
        matches!(self, SyntaxKind::WHITESPACE | SyntaxKind::COMMENT)
    }
diff --git a/crates/parser/src/syntax_kind/generated.rs b/crates/parser/src/syntax_kind/generated.rs
index 7d53cc4cd..bcefd183a 100644
--- a/crates/parser/src/syntax_kind/generated.rs
+++ b/crates/parser/src/syntax_kind/generated.rs
@@ -143,6 +143,7 @@ pub enum SyntaxKind {
    MACRO_DEF,
    PAREN_TYPE,
    TUPLE_TYPE,
+    MACRO_TYPE,
    NEVER_TYPE,
    PATH_TYPE,
    PTR_TYPE,
diff --git a/crates/proc_macro_api/Cargo.toml b/crates/proc_macro_api/Cargo.toml
index 1af2bbca7..078568cb2 100644
--- a/crates/proc_macro_api/Cargo.toml
+++ b/crates/proc_macro_api/Cargo.toml
@@ -11,7 +11,7 @@ doctest = false
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
-serde_json = "1.0"
+serde_json = { version = "1.0", features = ["unbounded_depth"] }
 log = "0.4.8"
 crossbeam-channel = "0.5.0"
 jod-thread = "0.1.1"
diff --git a/crates/proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt b/crates/proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
index e6fd21610..ea34e688f 100644
--- a/crates/proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
+++ b/crates/proc_macro_srv/src/tests/fixtures/test_serialize_proc_macro.txt
@@ -59,7 +59,7 @@ SUBTREE $
          IDENT   _serde 4294967295
          PUNCH   : [joint] 4294967295
          PUNCH   : [alone] 4294967295
-          IDENT   export 4294967295
+          IDENT   __private 4294967295
          PUNCH   : [joint] 4294967295
          PUNCH   : [alone] 4294967295
          IDENT   Ok 4294967295
@@ -72,7 +72,7 @@ SUBTREE $
          IDENT   _serde 4294967295
          PUNCH   : [joint] 4294967295
          PUNCH   : [alone] 4294967295
-          IDENT   export 4294967295
+          IDENT   __private 4294967295
          PUNCH   : [joint] 4294967295
          PUNCH   : [alone] 4294967295
          IDENT   Err 4294967295
@@ -85,7 +85,7 @@ SUBTREE $
            IDENT   _serde 4294967295
            PUNCH   : [joint] 4294967295
            PUNCH   : [alone] 4294967295
-            IDENT   export 4294967295
+            IDENT   __private 4294967295
            PUNCH   : [joint] 4294967295
            PUNCH   : [alone] 4294967295
            IDENT   Err 4294967295
@@ -120,7 +120,7 @@ SUBTREE $
      IDENT   _serde 4294967295
      PUNCH   : [joint] 4294967295
      PUNCH   : [alone] 4294967295
-      IDENT   export 4294967295
+      IDENT   __private 4294967295
      PUNCH   : [joint] 4294967295
      PUNCH   : [alone] 4294967295
      IDENT   Result 4294967295
diff --git a/crates/proc_macro_srv/src/tests/mod.rs b/crates/proc_macro_srv/src/tests/mod.rs
index 1a827cbd7..fd54f8dfd 100644
--- a/crates/proc_macro_srv/src/tests/mod.rs
+++ b/crates/proc_macro_srv/src/tests/mod.rs
@@ -38,9 +38,9 @@ fn test_derive_proc_macro_list() {
    let res = list("serde_derive", "1").join("\n");
    assert_eq_text!(
-        &res,
        r#"Serialize [CustomDerive]
-Deserialize [CustomDerive]"#
+Deserialize [CustomDerive]"#,
+        &res
    );
 }
@@ -50,9 +50,9 @@ fn list_test_macros() {
    let res = list("proc_macro_test", "0.0.0").join("\n");
    assert_eq_text!(
-        &res,
        r#"function_like_macro [FuncLike]
 attribute_macro [Attr]
-DummyTrait [CustomDerive]"#
+DummyTrait [CustomDerive]"#,
+        &res
    );
 }
diff --git a/crates/proc_macro_srv/src/tests/utils.rs b/crates/proc_macro_srv/src/tests/utils.rs
index 36942147d..196abb8fc 100644
--- a/crates/proc_macro_srv/src/tests/utils.rs
+++ b/crates/proc_macro_srv/src/tests/utils.rs
@@ -52,7 +52,7 @@ pub fn assert_expand(
    let fixture = parse_string(ra_fixture).unwrap();
    let res = expander.expand(macro_name, &fixture.subtree, None).unwrap();
-    assert_eq_text!(&format!("{:?}", res), &expect.trim());
+    assert_eq_text!(&expect.trim(), &format!("{:?}", res));
 }
 pub fn list(crate_name: &str, version: &str) -> Vec<String> {
diff --git a/crates/profile/Cargo.toml b/crates/profile/Cargo.toml
index 096233a09..f7231c2b8 100644
--- a/crates/profile/Cargo.toml
+++ b/crates/profile/Cargo.toml
@@ -13,13 +13,15 @@ doctest = false
 once_cell = "1.3.1"
 cfg-if = "1"
 libc = "0.2.73"
-la-arena = "0.1.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
+jemalloc-ctl = { version = "0.3.3", optional = true }
 [target.'cfg(target_os = "linux")'.dependencies]
 perf-event = "0.4"
 [features]
 cpu_profiler = []
+jemalloc = ["jemalloc-ctl"]
 # Uncomment to enable for the whole crate graph
 # default = [ "cpu_profiler" ]
diff --git a/crates/profile/src/memory_usage.rs b/crates/profile/src/memory_usage.rs
index 83390212a..cb4e54447 100644
--- a/crates/profile/src/memory_usage.rs
+++ b/crates/profile/src/memory_usage.rs
@@ -24,7 +24,12 @@ impl std::ops::Sub for MemoryUsage {
 impl MemoryUsage {
    pub fn current() -> MemoryUsage {
        cfg_if! {
-            if #[cfg(all(target_os = "linux", target_env = "gnu"))] {
+            if #[cfg(all(feature = "jemalloc", not(target_env = "msvc")))] {
+                jemalloc_ctl::epoch::advance().unwrap();
+                MemoryUsage {
+                    allocated: Bytes(jemalloc_ctl::stats::allocated::read().unwrap() as isize),
+                }
+            } else if #[cfg(all(target_os = "linux", target_env = "gnu"))] {
                // Note: This is incredibly slow.
                let alloc = unsafe { libc::mallinfo() }.uordblks as isize;
                MemoryUsage { allocated: Bytes(alloc) }
diff --git a/crates/project_model/Cargo.toml b/crates/project_model/Cargo.toml
index 51e7a7070..293cb5bfe 100644
--- a/crates/project_model/Cargo.toml
+++ b/crates/project_model/Cargo.toml
@@ -17,7 +17,7 @@ serde = { version = "1.0.106", features = ["derive"] }
 serde_json = "1.0.48"
 anyhow = "1.0.26"
 itertools = "0.10.0"
-la-arena = "0.1.0"
+la-arena = { version = "0.2.0", path = "../../lib/arena" }
 cfg = { path = "../cfg", version = "0.0.0" }
 base_db = { path = "../base_db", version = "0.0.0" }
@@ -25,3 +25,4 @@ toolchain = { path = "../toolchain", version = "0.0.0" }
 proc_macro_api =  { path = "../proc_macro_api", version = "0.0.0" }
 paths =  { path = "../paths", version = "0.0.0" }
 stdx =  { path = "../stdx", version = "0.0.0" }
+profile =  { path = "../profile", version = "0.0.0" }
diff --git a/crates/project_model/src/lib.rs b/crates/project_model/src/lib.rs
index aabb7a47d..970a7e140 100644
--- a/crates/project_model/src/lib.rs
+++ b/crates/project_model/src/lib.rs
@@ -5,6 +5,7 @@ mod cfg_flag;
 mod project_json;
 mod sysroot;
 mod workspace;
+mod rustc_cfg;
 use std::{
    fs::{read_dir, ReadDir},
diff --git a/crates/project_model/src/rustc_cfg.rs b/crates/project_model/src/rustc_cfg.rs
new file mode 100644
index 000000000..4a7bd8ae3
--- /dev/null
+++ b/crates/project_model/src/rustc_cfg.rs
@@ -0,0 +1,34 @@
+//! Runs `rustc --print cfg` to get built-in cfg flags.
+use std::process::Command;
+use crate::{cfg_flag::CfgFlag, utf8_stdout};
+pub(crate) fn get(target: Option<&str>) -> Vec<CfgFlag> {
+    let _p = profile::span("rustc_cfg::get");
+    let mut res = Vec::new();
+    // Some nightly-only cfgs, which are required for stdlib
+    res.push(CfgFlag::Atom("target_thread_local".into()));
+    for &ty in ["8", "16", "32", "64", "cas", "ptr"].iter() {
+        for &key in ["target_has_atomic", "target_has_atomic_load_store"].iter() {
+            res.push(CfgFlag::KeyValue { key: key.to_string(), value: ty.into() });
+        }
+    }
+    let rustc_cfgs = {
+        let mut cmd = Command::new(toolchain::rustc());
+        cmd.args(&["--print", "cfg", "-O"]);
+        if let Some(target) = target {
+            cmd.args(&["--target", target]);
+        }
+        utf8_stdout(cmd)
+    };
+    match rustc_cfgs {
+        Ok(rustc_cfgs) => res.extend(rustc_cfgs.lines().map(|it| it.parse().unwrap())),
+        Err(e) => log::error!("failed to get rustc cfgs: {:#}", e),
+    }
+    res
+}
diff --git a/crates/project_model/src/workspace.rs b/crates/project_model/src/workspace.rs
index 06a0be284..8e0481ae9 100644
--- a/crates/project_model/src/workspace.rs
+++ b/crates/project_model/src/workspace.rs
@@ -16,7 +16,7 @@ use proc_macro_api::ProcMacroClient;
 use rustc_hash::{FxHashMap, FxHashSet};
 use crate::{
-    cargo_workspace, cfg_flag::CfgFlag, sysroot::SysrootCrate, utf8_stdout, CargoConfig,
+    cargo_workspace, cfg_flag::CfgFlag, rustc_cfg, sysroot::SysrootCrate, utf8_stdout, CargoConfig,
    CargoWorkspace, ProjectJson, ProjectManifest, Sysroot, TargetKind,
 };
@@ -34,15 +34,25 @@ pub struct PackageRoot {
 #[derive(Clone, Eq, PartialEq)]
 pub enum ProjectWorkspace {
    /// Project workspace was discovered by running `cargo metadata` and `rustc --print sysroot`.
-    Cargo { cargo: CargoWorkspace, sysroot: Sysroot, rustc: Option<CargoWorkspace> },
+    Cargo {
+        cargo: CargoWorkspace,
+        sysroot: Sysroot,
+        rustc: Option<CargoWorkspace>,
+        /// Holds cfg flags for the current target. We get those by running
+        /// `rustc --print cfg`.
+        ///
+        /// FIXME: make this a per-crate map, as, eg, build.rs might have a
+        /// different target.
+        rustc_cfg: Vec<CfgFlag>,
+    },
    /// Project workspace was manually specified using a `rust-project.json` file.
-    Json { project: ProjectJson, sysroot: Option<Sysroot> },
+    Json { project: ProjectJson, sysroot: Option<Sysroot>, rustc_cfg: Vec<CfgFlag> },
 }
 impl fmt::Debug for ProjectWorkspace {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc } => f
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg } => f
                .debug_struct("Cargo")
                .field("n_packages", &cargo.packages().len())
                .field("n_sysroot_crates", &sysroot.crates().len())
@@ -50,13 +60,15 @@ impl fmt::Debug for ProjectWorkspace {
                    "n_rustc_compiler_crates",
                    &rustc.as_ref().map_or(0, |rc| rc.packages().len()),
                )
+                .field("rustc_cfg", rustc_cfg)
                .finish(),
-            ProjectWorkspace::Json { project, sysroot } => {
+            ProjectWorkspace::Json { project, sysroot, rustc_cfg } => {
                let mut debug_struct = f.debug_struct("Json");
                debug_struct.field("n_crates", &project.n_crates());
                if let Some(sysroot) = sysroot {
                    debug_struct.field("n_sysroot_crates", &sysroot.crates().len());
                }
+                debug_struct.field("rustc_cfg", rustc_cfg);
                debug_struct.finish()
            }
        }
@@ -79,7 +91,7 @@ impl ProjectWorkspace {
                })?;
                let project_location = project_json.parent().unwrap().to_path_buf();
                let project_json = ProjectJson::new(&project_location, data);
-                ProjectWorkspace::load_inline(project_json)?
+                ProjectWorkspace::load_inline(project_json, config.target.as_deref())?
            }
            ProjectManifest::CargoToml(cargo_toml) => {
                let cargo_version = utf8_stdout({
@@ -117,21 +129,24 @@ impl ProjectWorkspace {
                } else {
                    None
                };
+                let rustc_cfg = rustc_cfg::get(config.target.as_deref());
-                ProjectWorkspace::Cargo { cargo, sysroot, rustc }
+                ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg }
            }
        };
        Ok(res)
    }
-    pub fn load_inline(project_json: ProjectJson) -> Result<ProjectWorkspace> {
+    pub fn load_inline(
+        project_json: ProjectJson,
+        target: Option<&str>,
+    ) -> Result<ProjectWorkspace> {
        let sysroot = match &project_json.sysroot_src {
            Some(path) => Some(Sysroot::load(path)?),
            None => None,
        };
+        let rustc_cfg = rustc_cfg::get(target);
-        Ok(ProjectWorkspace::Json { project: project_json, sysroot })
+        Ok(ProjectWorkspace::Json { project: project_json, sysroot, rustc_cfg })
    }
    /// Returns the roots for the current `ProjectWorkspace`
@@ -139,7 +154,7 @@ impl ProjectWorkspace {
    /// the root is a member of the current workspace
    pub fn to_roots(&self) -> Vec<PackageRoot> {
        match self {
-            ProjectWorkspace::Json { project, sysroot } => project
+            ProjectWorkspace::Json { project, sysroot, rustc_cfg: _ } => project
                .crates()
                .map(|(_, krate)| PackageRoot {
                    is_member: krate.is_workspace_member,
@@ -156,7 +171,7 @@ impl ProjectWorkspace {
                    })
                }))
                .collect::<Vec<_>>(),
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc } => cargo
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg: _ } => cargo
                .packages()
                .map(|pkg| {
                    let is_member = cargo[pkg].is_member;
@@ -194,7 +209,7 @@ impl ProjectWorkspace {
    pub fn n_packages(&self) -> usize {
        match self {
            ProjectWorkspace::Json { project, .. } => project.n_crates(),
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc } => {
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, .. } => {
                let rustc_package_len = rustc.as_ref().map_or(0, |rc| rc.packages().len());
                cargo.packages().len() + sysroot.crates().len() + rustc_package_len
            }
@@ -203,22 +218,31 @@ impl ProjectWorkspace {
    pub fn to_crate_graph(
        &self,
-        target: Option<&str>,
        proc_macro_client: Option<&ProcMacroClient>,
        load: &mut dyn FnMut(&AbsPath) -> Option<FileId>,
    ) -> CrateGraph {
+        let _p = profile::span("ProjectWorkspace::to_crate_graph");
        let proc_macro_loader = |path: &Path| match proc_macro_client {
            Some(client) => client.by_dylib_path(path),
            None => Vec::new(),
        };
        let mut crate_graph = match self {
-            ProjectWorkspace::Json { project, sysroot } => {
+            ProjectWorkspace::Json { project, sysroot, rustc_cfg } => project_json_to_crate_graph(
-                project_json_to_crate_graph(target, &proc_macro_loader, load, project, sysroot)
+                rustc_cfg.clone(),
-            }
+                &proc_macro_loader,
-            ProjectWorkspace::Cargo { cargo, sysroot, rustc } => {
+                load,
-                cargo_to_crate_graph(target, &proc_macro_loader, load, cargo, sysroot, rustc)
+                project,
-            }
+                sysroot,
+            ),
+            ProjectWorkspace::Cargo { cargo, sysroot, rustc, rustc_cfg } => cargo_to_crate_graph(
+                rustc_cfg.clone(),
+                &proc_macro_loader,
+                load,
+                cargo,
+                sysroot,
+                rustc,