objc-arc: Add support for unbridged cast of

__builtin___CFStringMakeConstantString and CF typed function calls 
with explicit cf_returns_retained/cf_returns_not_retained attributes.
// rdar://9544832

llvm-svn: 133535

1 files changed, 39 insertions, 19 deletions

diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index ff3f837bace..83b01f24a21 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -1552,36 +1552,56 @@ namespace {
 
 bool
 Sema::ValidObjCARCNoBridgeCastExpr(Expr *&Exp, QualType castType) {
-  Expr *NewExp = Exp->IgnoreParenImpCasts();
+  Expr *NewExp = Exp->IgnoreParenCasts();
   
-  if (!isa<ObjCMessageExpr>(NewExp) && !isa<ObjCPropertyRefExpr>(NewExp))
+  if (!isa<ObjCMessageExpr>(NewExp) && !isa<ObjCPropertyRefExpr>(NewExp)
+      && !isa<CallExpr>(NewExp))
     return false;
   ObjCMethodDecl *method = 0;
+  bool MethodReturnsPlusOne = false;
+  
   if (ObjCPropertyRefExpr *PRE = dyn_cast<ObjCPropertyRefExpr>(NewExp)) {
     method = PRE->getExplicitProperty()->getGetterMethodDecl();
   }
-  else {
-    ObjCMessageExpr *ME = cast<ObjCMessageExpr>(NewExp);
+  else if (ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(NewExp))
     method = ME->getMethodDecl();
+  else {
+    CallExpr *CE = cast<CallExpr>(NewExp);
+    Decl *CallDecl = CE->getCalleeDecl();
+    if (!CallDecl)
+      return false;
+    if (CallDecl->hasAttr<CFReturnsNotRetainedAttr>())
+      return true;
+    MethodReturnsPlusOne = CallDecl->hasAttr<CFReturnsRetainedAttr>();
+    if (!MethodReturnsPlusOne) {
+      if (NamedDecl *ND = dyn_cast<NamedDecl>(CallDecl))
+        if (const IdentifierInfo *Id = ND->getIdentifier())
+          if (Id->isStr("__builtin___CFStringMakeConstantString"))
+            return true;
+    }
   }
-  if (!method)
-    return false;
-  if (method->hasAttr<CFReturnsNotRetainedAttr>())
-    return true;
-  bool MethodReturnsPlusOne = method->hasAttr<CFReturnsRetainedAttr>();
+  
   if (!MethodReturnsPlusOne) {
-    ObjCMethodFamily family = method->getSelector().getMethodFamily();
-    switch (family) {
-      case OMF_alloc:
-      case OMF_copy:
-      case OMF_mutableCopy:
-      case OMF_new:
-        MethodReturnsPlusOne = true;
-        break;
-      default:
-        break;
+    if (!method)
+      return false;
+    if (method->hasAttr<CFReturnsNotRetainedAttr>())
+      return true;
+    MethodReturnsPlusOne = method->hasAttr<CFReturnsRetainedAttr>();
+    if (!MethodReturnsPlusOne) {
+      ObjCMethodFamily family = method->getSelector().getMethodFamily();
+      switch (family) {
+        case OMF_alloc:
+        case OMF_copy:
+        case OMF_mutableCopy:
+        case OMF_new:
+          MethodReturnsPlusOne = true;
+          break;
+        default:
+          break;
+      }
     }
   }
+  
   if (MethodReturnsPlusOne) {
     TypeSourceInfo *TSInfo = 
       Context.getTrivialTypeSourceInfo(castType, SourceLocation());