r293808 - [Sema][ObjC] Don't pass a DeclRefExpr that doesn't reference a VarDecl

[Akira Hatanaka via cfe-commits]

Author: ahatanak
Date: Wed Feb  1 14:22:26 2017
New Revision: 293808

URL: http://llvm.org/viewvc/llvm-project?rev=293808&view=rev
Log:
[Sema][ObjC] Don't pass a DeclRefExpr that doesn't reference a VarDecl
to WeakObjectProfileTy's constructor.

This fixes an assertion failure in WeakObjectProfileTy's constructor.

rdar://problem/30112633

Modified:
    cfe/trunk/lib/Sema/ScopeInfo.cpp
    cfe/trunk/test/SemaObjC/arc-repeated-weak.mm

Modified: cfe/trunk/lib/Sema/ScopeInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/ScopeInfo.cpp?rev=293808&r1=293807&r2=293808&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/ScopeInfo.cpp (original)
+++ cfe/trunk/lib/Sema/ScopeInfo.cpp Wed Feb  1 14:22:26 2017
@@ -184,7 +184,7 @@ void FunctionScopeInfo::markSafeWeakUse(
   }
 
   // Has this weak object been seen before?
-  FunctionScopeInfo::WeakObjectUseMap::iterator Uses;
+  FunctionScopeInfo::WeakObjectUseMap::iterator Uses = WeakObjectUses.end();
   if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) {
     if (!RefExpr->isObjectReceiver())
       return;
@@ -197,10 +197,10 @@ void FunctionScopeInfo::markSafeWeakUse(
   }
   else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E))
     Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));
-  else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
-    Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
-  else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {
-    Uses = WeakObjectUses.end();
+  else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
+    if (isa<VarDecl>(DRE->getDecl()))
+      Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
+  } else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {
     if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {
       if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {
         Uses =

Modified: cfe/trunk/test/SemaObjC/arc-repeated-weak.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/arc-repeated-weak.mm?rev=293808&r1=293807&r2=293808&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjC/arc-repeated-weak.mm (original)
+++ cfe/trunk/test/SemaObjC/arc-repeated-weak.mm Wed Feb  1 14:22:26 2017
@@ -462,3 +462,16 @@ void foo() {
   use(NSBundle.foo2.weakProp); // expected-warning{{weak property 'weakProp' may be accessed multiple times}}
   use(NSBundle2.foo2.weakProp); // expected-note{{also accessed here}}
 }
+
+// This used to crash in the constructor of WeakObjectProfileTy when a
+// DeclRefExpr was passed that didn't reference a VarDecl.
+
+typedef INTF * INTFPtrTy;
+
+enum E {
+  e1
+};
+
+void foo1() {
+  INTFPtrTy tmp = (INTFPtrTy)e1; // expected-error{{cast of 'E' to 'INTFPtrTy' (aka 'INTF *') is disallowed with ARC}}
+}