[MS ABI] Allow a member pointers' converted type to change

Member pointers in the MS ABI are tricky for a variety of reasons.
The size of a member pointer is indeterminate until the program reaches
a point where the representation is required to be known.  However,
*pointers* to member pointers may exist without knowing the pointee
type's representation.  In these cases, we synthesize an opaque LLVM
type for the pointee type.

However, we can be in a situation where the underlying member pointer's
representation became known mid-way through the program.  To account for
this, we attempted to manicure CodeGen's type-cache so that we can
replace the opaque member pointer type with the real deal while leaving
the pointer types unperturbed.  This, unfortunately, is a problematic
approach to take as we will violate CodeGen's invariants.

These violations are mostly harmless but let's do the right thing
instead: invalidate the type-cache if a member pointer's LLVM
representation changes.

This fixes PR26313.

llvm-svn: 258839

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index bce19ab2fdb..9428bdf1db3 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -210,6 +210,13 @@ namespace {
         Builder->Release();
     }
 
+    void AssignInheritanceModel(CXXRecordDecl *RD) override {
+      if (Diags.hasErrorOccurred())
+        return;
+
+      Builder->RefreshTypeCacheForClass(RD);
+    }
+
     void CompleteTentativeDefinition(VarDecl *D) override {
       if (Diags.hasErrorOccurred())
         return;