[MS ABI, DebugInfo] Omit the size for model-less pointers-to-members

The representation of a pointer-to-member in the MS ABI is governed by
the layout of the relevant class or if a model has been explicitly
specified.  If no model is specified, then an appropriate
"worst-case-scenario" model is implicitly chosen if, and only, if the
pointer-to-member type's representation was needed.

Debug info cannot force a pointer-to-member type to have a
representation so do not try to query the size of such a type unless we
know it is safe to do so.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@238259 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index be684d46cb7b8aa7aa97a8b4bd93247f3e5027be..48458dbd600399a1c3c9c4e0f4c92b0f07443cdd 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1878,11 +1878,13 @@ llvm::DIType *CGDebugInfo::CreateType(const RValueReferenceType *Ty,
 
 llvm::DIType *CGDebugInfo::CreateType(const MemberPointerType *Ty,
                                       llvm::DIFile *U) {
+  uint64_t Size = CGM.getCXXABI().isTypeInfoCalculable(QualType(Ty, 0))
+                      ? CGM.getContext().getTypeSize(Ty)
+                      : 0;
   llvm::DIType *ClassType = getOrCreateType(QualType(Ty->getClass(), 0), U);
   if (Ty->isMemberDataPointerType())
     return DBuilder.createMemberPointerType(
-      getOrCreateType(Ty->getPointeeType(), U), ClassType,
-      CGM.getContext().getTypeSize(Ty));
+        getOrCreateType(Ty->getPointeeType(), U), ClassType, Size);
 
   const FunctionProtoType *FPT =
       Ty->getPointeeType()->getAs<FunctionProtoType>();
@@ -1890,7 +1892,7 @@ llvm::DIType *CGDebugInfo::CreateType(const MemberPointerType *Ty,
       getOrCreateInstanceMethodType(CGM.getContext().getPointerType(QualType(
                                         Ty->getClass(), FPT->getTypeQuals())),
                                     FPT, U),
-      ClassType, CGM.getContext().getTypeSize(Ty));
+      ClassType, Size);
 }
 
 llvm::DIType *CGDebugInfo::CreateType(const AtomicType *Ty, llvm::DIFile *U) {

diff --git a/test/CodeGenCXX/debug-info-ptr-to-member-function.cpp b/test/CodeGenCXX/debug-info-ptr-to-member-function.cpp
index 77b4ad2ed89536a7ee46431544a67eeb8d926e03..1b2cb578e60fafdeb29eee22571bb0f04452b117 100644 (file)
--- a/test/CodeGenCXX/debug-info-ptr-to-member-function.cpp
+++ b/test/CodeGenCXX/debug-info-ptr-to-member-function.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 %s -triple x86_64-apple-darwin -g -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -triple x86_64-apple-darwin -g -emit-llvm -o - | FileCheck -check-prefix=CHECK -check-prefix=DARWIN-X64 %s
+// RUN: %clang_cc1 %s -triple x86_64-pc-win32     -g -emit-llvm -o - | FileCheck -check-prefix=CHECK -check-prefix=WIN32-X64 %s
 
 struct T {
   int method();
@@ -8,4 +9,13 @@ void foo(int (T::*method)()) {}
 
 // A pointer to a member function is a pair of function- and this-pointer.
 // CHECK: !DIDerivedType(tag: DW_TAG_ptr_to_member_type,
-// CHECK-SAME:           size: 128
+// DARWIN-X64-SAME:      size: 128
+// WIN32-X64-SAME:       size: 64
+
+struct Incomplete;
+
+int (Incomplete::**bar)();
+// CHECK: !DIDerivedType(tag: DW_TAG_ptr_to_member_type,
+// DARWIN-X64-SAME:           size: 128
+// WIN32-X64-NOT:             size:
+// CHECK-SAME:                extraData: {{.*}})