In ARC, don't try to reclaim the result of a call to performSelector

unless done in a context where the value is used retained.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136769 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 44 insertions, 5 deletions

diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 0061db9730..ef4944ec35 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -4067,21 +4067,24 @@ ExprResult Sema::MaybeBindToTemporary(Expr *E) {
     // actual method.  FIXME: we should infer retention by selector in
     // cases where we don't have an actual method.
     } else {
-      Decl *D = 0;
+      ObjCMethodDecl *D = 0;
       if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) {
         D = Send->getMethodDecl();
       } else {
         CastExpr *CE = cast<CastExpr>(E);
-        // FIXME. What other cast kinds to check for?
-        if (CE->getCastKind() == CK_ObjCProduceObject ||
-            CE->getCastKind() == CK_LValueToRValue)
-          return MaybeBindToTemporary(CE->getSubExpr());
         assert(CE->getCastKind() == CK_GetObjCProperty);
         const ObjCPropertyRefExpr *PRE = CE->getSubExpr()->getObjCProperty();
         D = (PRE->isImplicitProperty() ? PRE->getImplicitPropertyGetter() : 0);
       }
 
       ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>());
+
+      // Don't do reclaims on performSelector calls; despite their
+      // return type, the invoked method doesn't necessarily actually
+      // return an object.
+      if (!ReturnsRetained &&
+          D && D->getMethodFamily() == OMF_performSelector)
+        return Owned(E);
     }
 
     ExprNeedsCleanups = true;
diff --git a/test/CodeGenObjC/arc.m b/test/CodeGenObjC/arc.m
index 109e360b79..4592710a3d 100644
--- a/test/CodeGenObjC/arc.m
+++ b/test/CodeGenObjC/arc.m
@@ -1754,3 +1754,39 @@ void test60b(void) {
   // CHECK-NEXT: call void @objc_release(i8* [[T2]])
   // CHECK-NEXT: ret void
 }
+
+// Verify that we don't try to reclaim the result of performSelector.
+// rdar://problem/9887545
+@interface Test61
+- (id) performSelector: (SEL) selector;
+- (void) test61_void;
+- (id) test61_id;
+@end
+void test61(void) {
+  // CHECK:    define void @test61()
+  // CHECK:      [[Y:%.*]] = alloca i8*, align 8
+
+  extern id test61_make(void);
+
+  // CHECK-NEXT: [[T0:%.*]] = call i8* @test61_make()
+  // CHECK-NEXT: [[T1:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T0]])
+  // CHECK-NEXT: [[T2:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_
+  // CHECK-NEXT: [[T3:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_
+  // CHECK-NEXT: [[T4:%.*]] = call i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*, i8*)*)(i8* [[T1]], i8* [[T3]], i8* [[T2]])
+  // CHECK-NEXT: call void @objc_release(i8* [[T1]])
+  [test61_make() performSelector: @selector(test61_void)];
+
+  // CHECK-NEXT: [[T0:%.*]] = call i8* @test61_make()
+  // CHECK-NEXT: [[T1:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T0]])
+  // CHECK-NEXT: [[T2:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_
+  // CHECK-NEXT: [[T3:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_
+  // CHECK-NEXT: [[T4:%.*]] = call i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*, i8*)*)(i8* [[T1]], i8* [[T3]], i8* [[T2]])
+  // CHECK-NEXT: [[T5:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T4]])
+  // CHECK-NEXT: store i8* [[T5]], i8** [[Y]]
+  // CHECK-NEXT: call void @objc_release(i8* [[T1]])
+  id y = [test61_make() performSelector: @selector(test61_id)];
+
+  // CHECK-NEXT: [[T0:%.*]] = load i8** [[Y]]
+  // CHECK-NEXT: call void @objc_release(i8* [[T0]])
+  // CHECK-NEXT: ret void
+}