Merge #692

692: [WIP] Correctly parse attributes  r=matklad a=DJMcNab

Reference - https://doc.rust-lang.org/reference/attributes.html
This fixes/investigates inner attributes for:

- [x] `impl` blocks
- [x] `extern` blocks
- [x] `fn`s (fixes #689)
- [x] `mod`s (already supported)
- [x] 'block expressions' (the long text just describes all 'blocks' used as statements)

This also investigates/fixes outer attributes for:

- [ ] 'most statements' (see also: #685, https://doc.rust-lang.org/reference/expressions.html#expression-attributes)
- [x] Enum variants, Struct and Union fields (Fixed in #507)
- [ ] 'Match expression arms' (@matklad can you provide a test case which explains what this means?)
- [ ] 'Generic lifetime or type parameters'
- [ ] 'Elements of array expressions, tuple expressions, call expressions, tuple-style struct and enum variant expressions'
- [ ] 'The tail expression of block expressions'

Co-authored-by: DJMcNab <[email protected]>

2 files changed, 43 insertions, 0 deletions

diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.rs
new file mode 100644
index 000000000..4d68cceb7
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.rs
@@ -0,0 +1,5 @@
+enum F{}
+impl F {
+     //! This is a doc comment
+     #![doc("This is also a doc comment")]
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.txt
new file mode 100644
index 000000000..3b761b7bb
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0118_impl_inner_attributes.txt
@@ -0,0 +1,38 @@
+SOURCE_FILE@[0; 94)
+  ENUM_DEF@[0; 8)
+    ENUM_KW@[0; 4)
+    WHITESPACE@[4; 5)
+    NAME@[5; 6)
+      IDENT@[5; 6) "F"
+    ENUM_VARIANT_LIST@[6; 8)
+      L_CURLY@[6; 7)
+      R_CURLY@[7; 8)
+  WHITESPACE@[8; 9)
+  IMPL_BLOCK@[9; 93)
+    IMPL_KW@[9; 13)
+    WHITESPACE@[13; 14)
+    PATH_TYPE@[14; 15)
+      PATH@[14; 15)
+        PATH_SEGMENT@[14; 15)
+          NAME_REF@[14; 15)
+            IDENT@[14; 15) "F"
+    WHITESPACE@[15; 16)
+    ITEM_LIST@[16; 93)
+      L_CURLY@[16; 17)
+      WHITESPACE@[17; 23)
+      COMMENT@[23; 48)
+      WHITESPACE@[48; 54)
+      ATTR@[54; 91)
+        POUND@[54; 55)
+        EXCL@[55; 56)
+        TOKEN_TREE@[56; 91)
+          L_BRACK@[56; 57)
+          IDENT@[57; 60) "doc"
+          TOKEN_TREE@[60; 90)
+            L_PAREN@[60; 61)
+            STRING@[61; 89)
+            R_PAREN@[89; 90)
+          R_BRACK@[90; 91)
+      WHITESPACE@[91; 92)
+      R_CURLY@[92; 93)
+  WHITESPACE@[93; 94)