Sema: Add a flag for rejecting member pointers with incomplete base types.

Codebases that need to be compatible with the Microsoft ABI can pass
this flag to avoid issues caused by the lack of a fixed ABI for
incomplete member pointers.

Differential Revision: https://reviews.llvm.org/D47503

llvm-svn: 333498

1 files changed, 11 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 7e8f9b19e3d..b5a90af39ba 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -7585,11 +7585,17 @@ bool Sema::RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
   //  assert(!T->isDependentType() &&
   //         "Can't ask whether a dependent type is complete");
 
-  // We lock in the inheritance model once somebody has asked us to ensure
-  // that a pointer-to-member type is complete.
-  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
-    if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>()) {
-      if (!MPTy->getClass()->isDependentType()) {
+  if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>()) {
+    if (!MPTy->getClass()->isDependentType()) {
+      if (getLangOpts().CompleteMemberPointers &&
+          !MPTy->getClass()->getAsCXXRecordDecl()->isBeingDefined() &&
+          RequireCompleteType(Loc, QualType(MPTy->getClass(), 0),
+                              diag::err_memptr_incomplete))
+        return true;
+
+      // We lock in the inheritance model once somebody has asked us to ensure
+      // that a pointer-to-member type is complete.
+      if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
         (void)isCompleteType(Loc, QualType(MPTy->getClass(), 0));
         assignInheritanceModel(*this, MPTy->getMostRecentCXXRecordDecl());
       }