Don't try to do RVO on block variables that refer to an enclosing local.

Fixes PR13314, clang crashing on blocks refering to an enclosing local
when the enclosing function returns void.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160089 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 9be1d34dae7aac0a1a44c7e098303ef93124ce76..54ec58af419d64cc86d23aa85295649c837fe5f6 100644 (file)
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2035,7 +2035,7 @@ const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType,
   // ... the expression is the name of a non-volatile automatic object
   // (other than a function or catch-clause parameter)) ...
   const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens());
-  if (!DR)
+  if (!DR || DR->refersToEnclosingLocal())
     return 0;
   const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl());
   if (!VD)

diff --git a/test/CodeGenObjCXX/blocks.mm b/test/CodeGenObjCXX/blocks.mm
index 72af74f1ebf76aef35b02a60ab03e684d4530397..62ae428e5ec169e8f970f39784f310e30beda57d 100644 (file)
--- a/test/CodeGenObjCXX/blocks.mm
+++ b/test/CodeGenObjCXX/blocks.mm
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -x objective-c++ -fblocks -triple x86_64-apple-darwin -fobjc-runtime=macosx-fragile-10.5 %s -verify -emit-llvm -o %t
+// RUN: %clang_cc1 -x objective-c++ -fblocks -triple x86_64-apple-darwin -fobjc-runtime=macosx-fragile-10.5 %s -verify -std=c++11 -emit-llvm -o %t
 // rdar://8979379
 
 @interface A
@@ -30,7 +30,7 @@ void foo(id <NSObject>(^objectCreationBlock)(void)) {
 
 // Test4
 struct S {
-  S *(^a)() = ^{ // expected-warning {{C++11}}
+  S *(^a)() = ^{
     return this;
   };
 };
@@ -40,7 +40,22 @@ S s;
 struct X {
   void f() {
     ^ {
-      struct Nested { Nested *ptr = this; }; // expected-warning {{C++11}}
+      struct Nested { Nested *ptr = this; };
     } ();
   };
 };
+
+// Regression test for PR13314
+class FooClass { };
+void fun() {
+  FooClass foovar;
+  ^() {  // expected-warning {{expression result unused}}
+    return foovar;
+  };
+}
+void gun() {
+  FooClass foovar;
+  [=]() {  // expected-warning {{expression result unused}}
+    return foovar;
+  };
+}