[TBAA] Only emit pointer tbaa metedata for record types.

Be conservative if the type isn't a record type. Handling other types may
require stripping const-qualifiers inside the type, e.g. MemberPointerType.

Without this, we assign different tags to the accesses for p an q in the
second test in cwg158.

Author: fhahn

clang/lib/CodeGen/CodeGenTBAA.cpp

@@ -230,6 +230,12 @@ llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
               ->getString();
       TyName = Name;
     } else {
+      // Be conservative if the type isn't a record type. Handling other types
+      // may require stripping const-qualifiers inside the type, e.g.
+      // MemberPointerType.
+      if (!Ty->isRecordType())
+        return AnyPtr;
+
       // For non-builtin types use the mangled name of the canonical type.
       llvm::raw_svector_ostream TyOut(TyName);
       MangleCtx->mangleCanonicalTypeName(QualType(Ty, 0), TyOut);

clang/test/CXX/drs/cwg158.cpp

@@ -1,8 +1,8 @@
-// RUN: %clang_cc1 -triple x86_64-linux -std=c++98 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK,DEFAULT %s
-// RUN: %clang_cc1 -triple x86_64-linux -std=c++11 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK,DEFAULT %s
-// RUN: %clang_cc1 -triple x86_64-linux -std=c++14 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK,DEFAULT %s
-// RUN: %clang_cc1 -triple x86_64-linux -std=c++1z %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK,DEFAULT %s
-// RUN: %clang_cc1 -triple x86_64-linux -std=c++1z %s -O3 -pointer-tbaa -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK,POINTER-TBAA %s
+// RUN: %clang_cc1 -triple x86_64-linux -std=c++98 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK %s
+// RUN: %clang_cc1 -triple x86_64-linux -std=c++11 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK %s
+// RUN: %clang_cc1 -triple x86_64-linux -std=c++14 %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK %s
+// RUN: %clang_cc1 -triple x86_64-linux -std=c++1z %s -O3 -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK %s
+// RUN: %clang_cc1 -triple x86_64-linux -std=c++1z %s -O3 -pointer-tbaa -disable-llvm-passes -pedantic-errors -emit-llvm -o - | FileCheck --check-prefixes=CHECK %s
 
 // cwg158: yes
 
@@ -23,8 +23,7 @@ const int *(A::*const *g(const int *(A::* const **p)[3], int *(A::***q)[3]))[3]
   // CHECK: load ptr, ptr %p.addr
   // CHECK: load ptr, {{.*}}, !tbaa ![[MEMPTR_TBAA:[^,]*]]
   const int *(A::*const *x)[3] = *p;
-  // DEFAULT: store ptr null, {{.*}}, !tbaa ![[MEMPTR_TBAA]]
-  // POINTER-TBAA-NOT: store ptr null, {{.*}}, !tbaa ![[MEMPTR_TBAA]]
+  // CHECK: store ptr null, {{.*}}, !tbaa ![[MEMPTR_TBAA]]
   *q = 0;
   return x;
 }