objc-arc: Perform null check on receiver before sending methods which

consume one or more of their arguments. If not done, this will cause a leak
as method will not consume the argument when receiver is null.
// rdar://10444474


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149184 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 3 deletions

diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index 446bef1249..49979f3279 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -136,7 +136,7 @@ RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
   bool isDelegateInit = E->isDelegateInitCall();
 
   const ObjCMethodDecl *method = E->getMethodDecl();
-
+  
   // We don't retain the receiver in delegate init calls, and this is
   // safe because the receiver value is always loaded from 'self',
   // which we zero out.  We don't want to Block_copy block receivers,
@@ -191,6 +191,19 @@ RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
     break;
   }
 
+  // Check to see if receiver must be null checked before method is sent
+  // to the receiver.
+  NullReturnState nullReturn;
+  if (CGM.getLangOptions().ObjCAutoRefCount && method)
+    for (ObjCMethodDecl::param_const_iterator i = method->param_begin(), 
+         e = method->param_end(); i != e; ++i) {
+      const ParmVarDecl *ParamDecl = (*i);
+      if (ParamDecl->hasAttr<NSConsumedAttr>()) {
+        nullReturn.init(*this, Receiver);
+        break;
+      } 
+    }
+
   if (retainSelf)
     Receiver = EmitARCRetainNonBlock(Receiver);
 
@@ -262,8 +275,8 @@ RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
 
     Builder.CreateStore(newSelf, selfAddr);
   }
-
-  return AdjustRelatedResultType(*this, E, method, result);
+  RValue rvalue = AdjustRelatedResultType(*this, E, method, result);
+  return nullReturn.complete(*this, rvalue, ResultType);
 }
 
 namespace {
@@ -292,6 +305,7 @@ struct FinishARCDealloc : EHScopeStack::Cleanup {
                                                       method);
   }
 };
+
 }
 
 /// StartObjCMethod - Begin emission of an ObjCMethod. This generates