Flag unsafe blocks from format! as compiler-generated

src/libsyntax/ast.rs

@@ -479,7 +479,13 @@ pub struct Field {
 #[deriving(Clone, Eq, Encodable, Decodable, IterBytes)]
 pub enum BlockCheckMode {
     DefaultBlock,
-    UnsafeBlock(/* generated internally */ bool),
+    UnsafeBlock(UnsafeSource),
+}
+
+#[deriving(Clone, Eq, Encodable, Decodable, IterBytes)]
+pub enum UnsafeSource {
+    CompilerGenerated,
+    UserProvided,
 }
 
 #[deriving(Clone, Eq, Encodable, Decodable,IterBytes)]

src/libsyntax/ext/ifmt.rs

@@ -632,7 +632,7 @@ impl Context {
            stmts: ~[],
            expr: Some(result),
            id: ast::DUMMY_NODE_ID,
-           rules: ast::UnsafeBlock,
+           rules: ast::UnsafeBlock(ast::CompilerGenerated),
            span: self.fmtsp,
         });
 

src/libsyntax/parse/parser.rs

@@ -1792,7 +1792,7 @@ impl Parser {
         } else if self.eat_keyword(keywords::Match) {
             return self.parse_match_expr();
         } else if self.eat_keyword(keywords::Unsafe) {
-            return self.parse_block_expr(lo, UnsafeBlock(false));
+            return self.parse_block_expr(lo, UnsafeBlock(ast::UserProvided));
         } else if *self.token == token::LBRACKET {
             self.bump();
             let mutbl = self.parse_mutability();