Auto merge of #36029 - KiChjang:issue-12033, r=arielb1

bors · web-flow · commit 312734ca4295 · 2016-08-28T13:16:47.000-07:00
Fix lifetime rules for 'if' conditions Fixes #12033. Changes the temporary scope rules to make the condition of an if-then-else a terminating scope. This is a [breaking-change].
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
@@ -803,7 +803,8 @@ fn resolve_expr(visitor: &mut RegionResolutionVisitor, expr: &hir::Expr) {
                 terminating(r.id);
             }
 
-            hir::ExprIf(_, ref then, Some(ref otherwise)) => {
+            hir::ExprIf(ref expr, ref then, Some(ref otherwise)) => {
+                terminating(expr.id);
                 terminating(then.id);
                 terminating(otherwise.id);
             }
diff --git a/src/test/run-pass/issue-12033.rs b/src/test/run-pass/issue-12033.rs
@@ -0,0 +1,16 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::cell::RefCell;
+
+fn main() {
+    let x = RefCell::new(0);
+    if *x.borrow() == 0 {} else {}
+}

Original file line number	Diff line number	Diff line change
`@@ -803,7 +803,8 @@ fn resolve_expr(visitor: &mut RegionResolutionVisitor, expr: &hir::Expr) {`
`803`	`803`	`terminating(r.id);`
`804`	`804`	`}`
`805`	`805`
`806`		`- hir::ExprIf(_, ref then, Some(ref otherwise)) => {`
	`806`	`+ hir::ExprIf(ref expr, ref then, Some(ref otherwise)) => {`
	`807`	`+ terminating(expr.id);`
`807`	`808`	`terminating(then.id);`
`808`	`809`	`terminating(otherwise.id);`
`809`	`810`	`}`