[CodeView] Improve debugging of virtual base class member variables

Initial support for passing the virtual base pointer offset to CodeViewDebug.

https://reviews.llvm.org/D46271

llvm-svn: 332296

2 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 0af3d1521eb..ef279417b7e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -2099,8 +2099,7 @@ CodeViewDebug::lowerRecordFieldList(const DICompositeType *Ty) {
   for (const DIDerivedType *I : Info.Inheritance) {
     if (I->getFlags() & DINode::FlagVirtual) {
       // Virtual base.
-      // FIXME: Emit VBPtrOffset when the frontend provides it.
-      unsigned VBPtrOffset = 0;
+      unsigned VBPtrOffset = I->getVBPtrOffset();
       // FIXME: Despite the accessor name, the offset is really in bytes.
       unsigned VBTableIndex = I->getOffsetInBits() / 4;
       auto RecordKind = (I->getFlags() & DINode::FlagIndirectVirtualBase) == DINode::FlagIndirectVirtualBase
diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 8596ebd9527..90a089bb969 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -318,10 +318,14 @@ DIDerivedType *DIBuilder::createFriend(DIType *Ty, DIType *FriendTy) {
 
 DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
                                             uint64_t BaseOffset,
+                                            uint32_t VBPtrOffset,
                                             DINode::DIFlags Flags) {
   assert(Ty && "Unable to create inheritance");
+  Metadata *ExtraData = ConstantAsMetadata::get(
+      ConstantInt::get(IntegerType::get(VMContext, 32), VBPtrOffset));
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_inheritance, "", nullptr,
-                            0, Ty, BaseTy, 0, 0, BaseOffset, None, Flags);
+                            0, Ty, BaseTy, 0, 0, BaseOffset, None,
+                            Flags, ExtraData);
 }
 
 DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,