Fix DebugInfo replaceAllUsesWith.

Summary:
replaceAllUsesWith had been modified to allow a DbgNode value to be
replaced by itself. In that case a new node is created by copying the
current DbgNode and the copy is used as replacement value.

When that copying happens, the value stored in this->DbgNode at the end
of RAUW would be a reference to the Node that has just been deleted.

This doesn't produce any bug right now, because the DI node on which we
call RAUW won't be used again.

Reviewers: dblaikie, echristo, aprantl

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5326

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217749 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index 71c32fc969d329b3ba0eb19800f4b8bf53cebb36..4274d82d15875ac4166d5fbd9dbe4f09c21db954 100644 (file)
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -384,7 +384,7 @@ void DIDescriptor::replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D) {
   const Value *V = cast_or_null<Value>(DN);
   Node->replaceAllUsesWith(const_cast<Value *>(V));
   MDNode::deleteTemporary(Node);
-  DbgNode = D;
+  DbgNode = DN;
 }
 
 /// replaceAllUsesWith - Replace all uses of the MDNode used by this