[codeview] Emit base class information from DW_TAG_inheritance nodes

There are two remaining issues here:
1. No vbptr information
2. Need to mention indirect virtual bases

Getting indirect virtual bases is just a matter of adding an "indirect"
flag, emitting them in the frontend, and ignoring them when appropriate
for DWARF.

All virtual bases use the same artificial vbptr field, so I think the
vbptr offset will be best represented by an implicit __vbptr$ClassName
member similar to our existing __vptr$ member.

llvm-svn: 273688

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
index 7db4e041096..53493725c13 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -157,6 +157,8 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
   /// Number of type lowering frames active on the stack.
   unsigned TypeEmissionLevel = 0;
 
+  codeview::TypeIndex VBPType;
+
   const DISubprogram *CurrentSubprogram = nullptr;
 
   // The UDTs we have seen while processing types; each entry is a pair of type
@@ -230,6 +232,8 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
 
   codeview::TypeIndex getScopeIndex(const DIScope *Scope);
 
+  codeview::TypeIndex getVBPTypeIndex();
+
   void addToUDTs(const DIType *Ty, codeview::TypeIndex TI);
 
   codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);