Merge #1928

1928: Support `#[cfg(..)]` r=matklad a=oxalica

This PR implement `#[cfg(..)]` conditional compilation. It read default cfg options from `rustc --print cfg` with also hard-coded `test` and `debug_assertion` enabled.
Front-end settings are **not** included in this PR.

There is also a known issue that inner control attributes are totally ignored. I think it is **not** a part of `cfg` and create a separated issue for it. #1949

Fixes #1920 

Related: #1073 


Co-authored-by: uHOOCCOOHu <[email protected]>
Co-authored-by: oxalica <[email protected]>

2 files changed, 3 insertions, 1 deletions

diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 3bb5571ee..34b22c3e2 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1962,6 +1962,7 @@ impl AstNode for ModuleItem {
         }
     }
 }
+impl ast::AttrsOwner for ModuleItem {}
 impl ModuleItem {}
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct Name {
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 17477a696..25e6f64ce 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -397,7 +397,8 @@ Grammar(
         ),
         "ModuleItem": (
             enum: ["StructDef", "EnumDef", "FnDef", "TraitDef", "TypeAliasDef", "ImplBlock",
-                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ]
+                   "UseItem", "ExternCrateItem", "ConstDef", "StaticDef", "Module" ],
+            traits: ["AttrsOwner"]
         ),
         "ImplItem": (
             enum: ["FnDef", "TypeAliasDef", "ConstDef"]