When a function-local value with function-local metadata uses gets RAUWed with a

non-function-local value, it may result in the metadata no longer needing to be
function-local. Check for this condition, and clear the isFunctionLocal flag, if
it's still in the uniquing map, since any node in the uniquing map needs to have
an accurate function-local flag.

Also, add an assert to help catch problematic cases.

llvm-svn: 113828

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/Metadata.cpp b/llvm/lib/VMCore/Metadata.cpp
index b9f97dbf603..da69c43ff73 100644
--- a/llvm/lib/VMCore/Metadata.cpp
+++ b/llvm/lib/VMCore/Metadata.cpp
@@ -354,6 +354,22 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {
 
   // InsertPoint will have been set by the FindNodeOrInsertPos call.
   pImpl->MDNodeSet.InsertNode(this, InsertPoint);
+
+  // If this MDValue was previously function-local but no longer is, clear
+  // its function-local flag.
+  if (isFunctionLocal() && !isFunctionLocalValue(To)) {
+    bool isStillFunctionLocal = false;
+    for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
+      Value *V = getOperand(i);
+      if (!V) continue;
+      if (isFunctionLocalValue(V)) {
+        isStillFunctionLocal = true;
+        break;
+      }
+    }
+    if (!isStillFunctionLocal)
+      setValueSubclassData(getSubclassDataFromValue() & ~FunctionLocalBit);
+  }
 }
 
 //===----------------------------------------------------------------------===//
@@ -387,6 +403,8 @@ MDNode *NamedMDNode::getOperand(unsigned i) const {
 
 /// addOperand - Add metadata Operand.
 void NamedMDNode::addOperand(MDNode *M) {
+  assert(!M->isFunctionLocal() &&
+         "NamedMDNode operands must not be function-local!");
   getNMDOps(Operands).push_back(TrackingVH<MDNode>(M));
 }