Parse and validate attributes in blocks

crates/ra_syntax/src/ast/generated.rs

@@ -272,6 +272,7 @@ impl ToOwned for Block {
 }
 
 
+impl ast::AttrsOwner for Block {}
 impl Block {
     pub fn statements(&self) -> impl Iterator<Item = &Stmt> {
         super::children(self)

crates/ra_syntax/src/grammar.ron

@@ -571,6 +571,9 @@ Grammar(
             options: [ "Expr" ],
             collections: [
                 ["statements", "Stmt"],
+            ],
+            traits: [
+                "AttrsOwner",
             ]
         ),
         "ParamList": (

crates/ra_syntax/src/grammar/expressions.rs

@@ -42,6 +42,8 @@ pub(crate) fn block(p: &mut Parser) {
     }
     let m = p.start();
     p.bump();
+    // This is checked by a validator
+    attributes::inner_attributes(p);
 
     while !p.at(EOF) && !p.at(R_CURLY) {
         match p.current() {

crates/ra_syntax/src/validation.rs

@@ -2,6 +2,7 @@ mod byte;
 mod byte_string;
 mod char;
 mod string;
+mod block;
 
 use crate::{
     SourceFile, yellow::SyntaxError, AstNode,
@@ -17,6 +18,7 @@ pub(crate) fn validate(file: &SourceFile) -> Vec<SyntaxError> {
             .visit::<ast::ByteString, _>(self::byte_string::validate_byte_string_node)
             .visit::<ast::Char, _>(self::char::validate_char_node)
             .visit::<ast::String, _>(self::string::validate_string_node)
+            .visit::<ast::Block, _>(self::block::validate_block_node)
             .accept(node);
     }
     errors

crates/ra_syntax/src/validation/block.rs

@@ -0,0 +1,24 @@
+use crate::{SyntaxKind::*,
+    ast::{self, AttrsOwner, AstNode},
+    yellow::{
+        SyntaxError,
+        SyntaxErrorKind::*,
+    },
+};
+
+pub(crate) fn validate_block_node(node: &ast::Block, errors: &mut Vec<SyntaxError>) {
+    if let Some(parent) = node.syntax().parent() {
+        match parent.kind() {
+            FN_DEF => return,
+            BLOCK_EXPR => match parent.parent().map(|v| v.kind()) {
+                Some(EXPR_STMT) | Some(BLOCK) => return,
+                _ => {}
+            },
+            _ => {}
+        }
+    }
+    errors.extend(
+        node.attrs()
+            .map(|attr| SyntaxError::new(InvalidBlockAttr, attr.syntax().range())),
+    )
+}

crates/ra_syntax/src/yellow/syntax_error.rs

@@ -94,6 +94,7 @@ pub enum SyntaxErrorKind {
     UnicodeEscapeOutOfRange,
     UnclosedString,
     InvalidSuffix,
+    InvalidBlockAttr,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -136,6 +137,9 @@ impl fmt::Display for SyntaxErrorKind {
             UnicodeEscapeOutOfRange => write!(f, "Unicode escape code should be at most 0x10FFFF"),
             UnclosedString => write!(f, "Unclosed string literal"),
             InvalidSuffix => write!(f, "Invalid literal suffix"),
+            InvalidBlockAttr => {
+                write!(f, "A block in this position cannot accept inner attributes")
+            }
             ParseError(msg) => write!(f, "{}", msg.0),
         }
     }