From e71202efccdead44c8a3d4a2296d866d0e89799b Mon Sep 17 00:00:00 2001
From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Fri, 4 Nov 2011 20:37:24 +0000
Subject: [PATCH] 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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143736 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaType.cpp | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 09d47e8e17..219a9e8a30 100644
--- a/lib/Sema/SemaType.cpp
+++ b/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.
-- 
2.40.0