auto merge of #9013 : alexcrichton/rust/generated-unsafe-blocks, r=sanxiyn

This way syntax extensions can generate unsafe blocks without worrying about them generating unnecessary unsafe warnings. Perhaps a special keyword could be added to be used in macros, but I don't think that's the best solution.

Currently if you use `format!` and friends in an `unsafe` block you're guaranteed to get some unused-unsafe warnings which is unfortunate. We normally do want these warnings, but I'm ok ignoring them in the case of compiler-generated unsafe blocks. I tried to do this in the least intrusive way possible, but others may have better ideas about how to do this.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 4adc34d75a7..b5772a9eede 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/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);
+            return self.parse_block_expr(lo, UnsafeBlock(ast::UserProvided));
         } else if *self.token == token::LBRACKET {
             self.bump();
             let mutbl = self.parse_mutability();