Fix bug in getCompleteTypeIndex in codeview debug info

Summary:
When there are multiple instances of a forward decl record type, only the first one is emitted with a type index, because
the type is added to a map with a null type index. Avoid this by reordering so that forward decl types aren't added to the map.

Reviewers: rnk

Subscribers: aprantl, hiraditya, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61460

llvm-svn: 360101

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index db6a899a5da..c4e7edc0858 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -2497,11 +2497,7 @@ TypeIndex CodeViewDebug::getCompleteTypeIndex(DITypeRef TypeRef) {
     return getTypeIndex(Ty);
   }
 
-  // Check if we've already translated the complete record type.
   const auto *CTy = cast<DICompositeType>(Ty);
-  auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()});
-  if (!InsertResult.second)
-    return InsertResult.first->second;
 
   TypeLoweringScope S(*this);
 
@@ -2519,6 +2515,13 @@ TypeIndex CodeViewDebug::getCompleteTypeIndex(DITypeRef TypeRef) {
       return FwdDeclTI;
   }
 
+  // Check if we've already translated the complete record type.
+  // Insert the type with a null TypeIndex to signify that the type is currently
+  // being lowered.
+  auto InsertResult = CompleteTypeIndices.insert({CTy, TypeIndex()});
+  if (!InsertResult.second)
+    return InsertResult.first->second;
+
   TypeIndex TI;
   switch (CTy->getTag()) {
   case dwarf::DW_TAG_class_type: