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, 129 insertions, 0 deletions

diff --git a/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.rs b/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.rs
new file mode 100644
index 000000000..6a04f2d0a
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.rs
@@ -0,0 +1,15 @@
+fn block() {
+    let inner = {
+        #![doc("Inner attributes not allowed here")]
+        //! Nor are ModuleDoc comments
+    };
+    if true {
+        #![doc("Nor here")]
+        #![doc("We error on each attr")]
+        //! Nor are ModuleDoc comments
+    }
+    while true {
+        #![doc("Nor here")]
+        //! Nor are ModuleDoc comments
+    }
+}
diff --git a/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.txt b/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.txt
new file mode 100644
index 000000000..086aa79ac
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/err/0031_block_inner_attrs.txt
@@ -0,0 +1,114 @@
+SOURCE_FILE@[0; 350)
+  FN_DEF@[0; 349)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 8)
+      IDENT@[3; 8) "block"
+    PARAM_LIST@[8; 10)
+      L_PAREN@[8; 9)
+      R_PAREN@[9; 10)
+    WHITESPACE@[10; 11)
+    BLOCK@[11; 349)
+      L_CURLY@[11; 12)
+      WHITESPACE@[12; 17)
+      LET_STMT@[17; 129)
+        LET_KW@[17; 20)
+        WHITESPACE@[20; 21)
+        BIND_PAT@[21; 26)
+          NAME@[21; 26)
+            IDENT@[21; 26) "inner"
+        WHITESPACE@[26; 27)
+        EQ@[27; 28)
+        WHITESPACE@[28; 29)
+        BLOCK_EXPR@[29; 128)
+          BLOCK@[29; 128)
+            L_CURLY@[29; 30)
+            WHITESPACE@[30; 39)
+            err: `A block in this position cannot accept inner attributes`
+            ATTR@[39; 83)
+              POUND@[39; 40)
+              EXCL@[40; 41)
+              TOKEN_TREE@[41; 83)
+                L_BRACK@[41; 42)
+                IDENT@[42; 45) "doc"
+                TOKEN_TREE@[45; 82)
+                  L_PAREN@[45; 46)
+                  STRING@[46; 81)
+                  R_PAREN@[81; 82)
+                R_BRACK@[82; 83)
+            WHITESPACE@[83; 92)
+            COMMENT@[92; 122)
+            WHITESPACE@[122; 127)
+            R_CURLY@[127; 128)
+        SEMI@[128; 129)
+      WHITESPACE@[129; 134)
+      EXPR_STMT@[134; 257)
+        IF_EXPR@[134; 257)
+          IF_KW@[134; 136)
+          WHITESPACE@[136; 137)
+          CONDITION@[137; 141)
+            LITERAL@[137; 141)
+              TRUE_KW@[137; 141)
+          WHITESPACE@[141; 142)
+          BLOCK@[142; 257)
+            L_CURLY@[142; 143)
+            WHITESPACE@[143; 152)
+            err: `A block in this position cannot accept inner attributes`
+            ATTR@[152; 171)
+              POUND@[152; 153)
+              EXCL@[153; 154)
+              TOKEN_TREE@[154; 171)
+                L_BRACK@[154; 155)
+                IDENT@[155; 158) "doc"
+                TOKEN_TREE@[158; 170)
+                  L_PAREN@[158; 159)
+                  STRING@[159; 169)
+                  R_PAREN@[169; 170)
+                R_BRACK@[170; 171)
+            WHITESPACE@[171; 180)
+            err: `A block in this position cannot accept inner attributes`
+            ATTR@[180; 212)
+              POUND@[180; 181)
+              EXCL@[181; 182)
+              TOKEN_TREE@[182; 212)
+                L_BRACK@[182; 183)
+                IDENT@[183; 186) "doc"
+                TOKEN_TREE@[186; 211)
+                  L_PAREN@[186; 187)
+                  STRING@[187; 210)
+                  R_PAREN@[210; 211)
+                R_BRACK@[211; 212)
+            WHITESPACE@[212; 221)
+            COMMENT@[221; 251)
+            WHITESPACE@[251; 256)
+            R_CURLY@[256; 257)
+      WHITESPACE@[257; 262)
+      WHILE_EXPR@[262; 347)
+        WHILE_KW@[262; 267)
+        WHITESPACE@[267; 268)
+        CONDITION@[268; 272)
+          LITERAL@[268; 272)
+            TRUE_KW@[268; 272)
+        WHITESPACE@[272; 273)
+        BLOCK@[273; 347)
+          L_CURLY@[273; 274)
+          WHITESPACE@[274; 283)
+          err: `A block in this position cannot accept inner attributes`
+          ATTR@[283; 302)
+            POUND@[283; 284)
+            EXCL@[284; 285)
+            TOKEN_TREE@[285; 302)
+              L_BRACK@[285; 286)
+              IDENT@[286; 289) "doc"
+              TOKEN_TREE@[289; 301)
+                L_PAREN@[289; 290)
+                STRING@[290; 300)
+                R_PAREN@[300; 301)
+              R_BRACK@[301; 302)
+          WHITESPACE@[302; 311)
+          COMMENT@[311; 341)
+          WHITESPACE@[341; 346)
+          R_CURLY@[346; 347)
+      WHITESPACE@[347; 348)
+      R_CURLY@[348; 349)
+  WHITESPACE@[349; 350)