From 6794236ad4eee9aabce39ba767bf16c6573a9339 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Tue, 23 Jan 2018 19:17:25 +0000
Subject: [PATCH] AST: adjust ObjC MS mangling to work with typedefs

Rather than hardcode the pointerness of the `id` and `class` types,
handle them generically.  This allows for the template type
specialization of `remove_pointer<id>` which would look through the `id`
type and deal with the `objc_object` structure without the pointer.

llvm-svn: 323241
---
 clang/lib/AST/MicrosoftMangle.cpp            |  5 ---
 clang/test/CodeGenObjCXX/msabi-objc-types.mm | 39 ++++++++++++++++----
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 0c55c1a92287..e97e8bda96f8 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -1833,11 +1833,9 @@ void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
     llvm_unreachable("placeholder types shouldn't get to name mangling");
 
   case BuiltinType::ObjCId:
-    Out << "PA";
     mangleArtificalTagType(TTK_Struct, "objc_object");
     break;
   case BuiltinType::ObjCClass:
-    Out << "PA";
     mangleArtificalTagType(TTK_Struct, "objc_class");
     break;
   case BuiltinType::ObjCSel:
@@ -2337,9 +2335,6 @@ void MicrosoftCXXNameMangler::mangleType(const PointerType *T, Qualifiers Quals,
 
 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectPointerType *T,
                                          Qualifiers Quals, SourceRange Range) {
-  if (T->isObjCIdType() || T->isObjCClassType())
-    return mangleType(T->getPointeeType(), Range, QMM_Drop);
-
   QualType PointeeType = T->getPointeeType();
   manglePointerCVQualifiers(Quals);
   manglePointerExtQualifiers(Quals, PointeeType);
diff --git a/clang/test/CodeGenObjCXX/msabi-objc-types.mm b/clang/test/CodeGenObjCXX/msabi-objc-types.mm
index 013a9c84daee..42db40a351b6 100644
--- a/clang/test/CodeGenObjCXX/msabi-objc-types.mm
+++ b/clang/test/CodeGenObjCXX/msabi-objc-types.mm
@@ -33,7 +33,7 @@ void g(id &) {}
 // CHECK-LABEL: "\01?g@@YAXAAPAUobjc_object@@@Z"
 
 void g(const id &) {}
-// CHECK-LABEL: "\01?g@@YAXABPAUobjc_object@@@Z"
+// CHECK-LABEL: "\01?g@@YAXABQAUobjc_object@@@Z"
 
 void g(id &&) {}
 // CHECK-LABEL: "\01?g@@YAX$$QAPAUobjc_object@@@Z"
@@ -45,7 +45,7 @@ void h(Class &) {}
 // CHECK-LABEL: "\01?h@@YAXAAPAUobjc_class@@@Z"
 
 void h(const Class &) {}
-// CHECK-LABEL: "\01?h@@YAXABPAUobjc_class@@@Z"
+// CHECK-LABEL: "\01?h@@YAXABQAUobjc_class@@@Z"
 
 void h(Class &&) {}
 // CHECK-LABEL: "\01?h@@YAX$$QAPAUobjc_class@@@Z"
@@ -62,6 +62,12 @@ I &k() { return *kI; }
 const I &l() { return *kI; }
 // CHECK-LABEL: "\01?l@@YAABUI@@XZ"
 
+void m(const id) {}
+// CHECK-LABEL: "\01?m@@YAXQAUobjc_object@@@Z"
+
+void m(const I *) {}
+// CHECK-LABEL: "\01?m@@YAXPBUI@@@Z"
+
 struct __declspec(dllexport) s {
   struct s &operator=(const struct s &) = delete;
 
@@ -93,16 +99,16 @@ struct __declspec(dllexport) s {
   // CHECK-LABEL: "\01?m@s@@QAAX$$QAPAUobjc_object@@@Z"
 
   void m(const id &) {}
-  // CHECK-LABEL: "\01?m@s@@QAAXABPAUobjc_object@@@Z"
+  // CHECK-LABEL: "\01?m@s@@QAAXABQAUobjc_object@@@Z"
 
   void m(const id &&) {}
-  // CHECK-LABEL: "\01?m@s@@QAAX$$QBPAUobjc_object@@@Z"
+  // CHECK-LABEL: "\01?m@s@@QAAX$$QBQAUobjc_object@@@Z"
 
   void m(Class *) {}
   // CHECK-LABEL: "\01?m@s@@QAAXPAPAUobjc_class@@@Z"
 
   void m(const Class *) {}
-  // CHECK-LABEL: "\01?m@s@@QAAXPBPAUobjc_class@@@Z"
+  // CHECK-LABEL: "\01?m@s@@QAAXPBQAUobjc_class@@@Z"
 
   void m(Class) {}
   // CHECK-LABEL: "\01?m@s@@QAAXPAUobjc_class@@@Z"
@@ -111,12 +117,31 @@ struct __declspec(dllexport) s {
   // CHECK-LABEL: "\01?m@s@@QAAXAAPAUobjc_class@@@Z"
 
   void m(const Class &) {}
-  // CHECK-LABEL: "\01?m@s@@QAAXABPAUobjc_class@@@Z"
+  // CHECK-LABEL: "\01?m@s@@QAAXABQAUobjc_class@@@Z"
 
   void m(Class &&) {}
   // CHECK-LABEL: "\01?m@s@@QAAX$$QAPAUobjc_class@@@Z"
 
   void m(const Class &&) {}
-  // CHECK-LABEL: "\01?m@s@@QAAX$$QBPAUobjc_class@@@Z"
+  // CHECK-LABEL: "\01?m@s@@QAAX$$QBQAUobjc_class@@@Z"
 };
 
+template <typename T>
+struct remove_pointer { typedef T type; };
+
+template <typename T>
+struct remove_pointer<T *> {
+  typedef T type;
+};
+
+template <typename T>
+struct t {
+  t() {}
+};
+
+template struct t<id>;
+// CHECK-LABEL: "\01??0?$t@PAUobjc_object@@@@QAA@XZ"
+
+template struct t<remove_pointer<id>::type>;
+// CHECK-LABEL: "\01??0?$t@Uobjc_object@@@@QAA@XZ"
+