From ff5abbb4d3948fbac154e38e4412d2b93f969846 Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Tue, 18 Mar 2014 02:35:03 +0000
Subject: [PATCH] DwarfDebug: Only unique retained types instead of all types.
 This is a follow-up to r203983 based on feedback from dblaikie and mren
 (Thanks!) No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204107 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 9 +++++++--
 lib/CodeGen/AsmPrinter/DwarfUnit.cpp  | 5 ++---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index ecd10460a59..87f1878e865 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -846,8 +846,13 @@ void DwarfDebug::beginModule() {
     for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
       CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
     DIArray RetainedTypes = CUNode.getRetainedTypes();
-    for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
-      CU->getOrCreateTypeDIE(RetainedTypes.getElement(i));
+    for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
+      DIType Ty(RetainedTypes.getElement(i));
+      // The retained types array by design contains pointers to
+      // MDNodes rather than DIRefs. Unique them here.
+      DIType UniqueTy(resolve(Ty.getRef()));
+      CU->getOrCreateTypeDIE(UniqueTy);
+    }
     // Emit imported_modules last so that the relevant context is already
     // available.
     for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index a7b43d80328..be21d633e54 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -971,6 +971,8 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
 
   DIType Ty(TyNode);
   assert(Ty.isType());
+  assert(*&Ty == resolve(Ty.getRef()) &&
+         "type was not uniqued, possible ODR violation.");
 
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE.
@@ -978,9 +980,6 @@ DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
   DIE *ContextDIE = getOrCreateContextDIE(Context);
   assert(ContextDIE);
 
-  // Unique the type. This is a noop if the type has no unique identifier.
-  Ty = DIType(resolve(Ty.getRef()));
-
   DIE *TyDIE = getDIE(Ty);
   if (TyDIE)
     return TyDIE;