In ARC, when applying an ownership to a non-objc pointer, instead of ignoring it

create an attributed type with same type as the original type.

We effectively retain the source info that an ownership attribute was present but the attribute
is ignored by not modifying the type that it was applied to.

llvm-svn: 143736

1 files changed, 31 insertions, 3 deletions

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 09d47e8e179..219a9e8a308 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -3258,8 +3258,21 @@ static void HandleAddressSpaceTypeAttribute(QualType &Type,
 static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
                                        AttributeList &attr,
                                        QualType &type) {
-  if (!type->isObjCRetainableType() && !type->isDependentType())
-    return false;
+  bool NonObjCPointer = false;
+
+  if (!type->isDependentType()) {
+    if (const PointerType *ptr = type->getAs<PointerType>()) {
+      QualType pointee = ptr->getPointeeType();
+      if (pointee->isObjCRetainableType() || pointee->isPointerType())
+        return false;
+      // It is important not to lose the source info that there was an attribute
+      // applied to non-objc pointer. We will create an attributed type but
+      // its type will be the same as the original type.
+      NonObjCPointer = true;
+    } else if (!type->isObjCRetainableType()) {
+      return false;
+    }
+  }
 
   Sema &S = state.getSema();
   SourceLocation AttrLoc = attr.getLoc();
@@ -3300,10 +3313,25 @@ static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
   if (!S.getLangOptions().ObjCAutoRefCount)
     return true;
 
+  if (NonObjCPointer) {
+    StringRef name = attr.getName()->getName();
+    switch (lifetime) {
+    case Qualifiers::OCL_None:
+    case Qualifiers::OCL_ExplicitNone:
+      break;
+    case Qualifiers::OCL_Strong: name = "__strong"; break;
+    case Qualifiers::OCL_Weak: name = "__weak"; break;
+    case Qualifiers::OCL_Autoreleasing: name = "__autoreleasing"; break;
+    }
+    S.Diag(AttrLoc, diag::warn_objc_object_attribute_wrong_type)
+      << name << type;
+  }
+
   Qualifiers qs;
   qs.setObjCLifetime(lifetime);
   QualType origType = type;
-  type = S.Context.getQualifiedType(type, qs);
+  if (!NonObjCPointer)
+    type = S.Context.getQualifiedType(type, qs);
 
   // If we have a valid source location for the attribute, use an
   // AttributedType instead.