DebugInfo: Introduce new DIValue, DIETypeSignature to encode references to type units via their signatures

This simplifies type unit and type unit reference creation as well as
setting the stage for inter-type hashing across type unit boundaries.

llvm-svn: 197539

1 files changed, 3 insertions, 7 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 2eda0e883ee..10ce17fa2dd 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -450,13 +450,9 @@ class DwarfDebug : public AsmPrinterHandler {
   ImportedEntityMap;
   ImportedEntityMap ScopesWithImportedEntities;
 
-  // Map from type MDNodes to a pair used as a union. If the pointer is
-  // non-null, proxy DIEs in CUs meant to reference this type should be stored
-  // in the vector. The hash will be added to these DIEs once it is computed. If
-  // the pointer is null, the hash is immediately available in the uint64_t and
-  // should be directly used for proxy DIEs.
-  DenseMap<const MDNode *, std::pair<uint64_t, SmallVectorImpl<DIE *> *> >
-  DwarfTypeUnits;
+  // Map from MDNodes for user-defined types to the type units that describe
+  // them.
+  DenseMap<const MDNode *, const DwarfTypeUnit *> DwarfTypeUnits;
 
   // Whether to emit the pubnames/pubtypes sections.
   bool HasDwarfPubSections;