Roll back r97918 again. Just configuring against llvm-gcc wasn't enough to run

the FrontendC* tests. :(


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97921 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 16 insertions, 25 deletions

diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 9978f40ed0..9887f28821 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -105,11 +105,6 @@ public:
   StringMap<MDString*> MDStringCache;
   
   FoldingSet<MDNode> MDNodeSet;
-  // MDNodes may be uniqued or not uniqued.  When they're not uniqued, they
-  // aren't in the MDNodeSet, but they're still shared between objects, so no
-  // one object can destroy them.  This set allows us to at least destroy them
-  // on Context destruction.
-  SmallPtrSet<MDNode*, 1> NonUniquedMDNodes;
   
   ConstantUniqueMap<char, Type, ConstantAggregateZero> AggZeroConstants;
 
@@ -240,21 +235,17 @@ public:
       (*I)->AbstractTypeUsers.clear();
       delete *I;
     }
-    // Destroy MDNodes.  ~MDNode can move and remove nodes between the MDNodeSet
-    // and the NonUniquedMDNodes sets, so copy the values out first.
-    SmallVector<MDNode*, 8> MDNodes;
-    MDNodes.reserve(MDNodeSet.size() + NonUniquedMDNodes.size());
+    // Destroy MDNode operands first.
     for (FoldingSetIterator<MDNode> I = MDNodeSet.begin(), E = MDNodeSet.end();
-         I != E; ++I) {
-      MDNodes.push_back(&*I);
+         I != E;) {
+      MDNode *N = &(*I);
+      ++I;
+      N->replaceAllOperandsWithNull();
     }
-    MDNodes.append(NonUniquedMDNodes.begin(), NonUniquedMDNodes.end());
-    for (SmallVector<MDNode*, 8>::iterator I = MDNodes.begin(),
-           E = MDNodes.end(); I != E; ++I) {
-      (*I)->destroy();
+    while (!MDNodeSet.empty()) {
+      MDNode *N = &(*MDNodeSet.begin());
+      N->destroy();
     }
-    assert(MDNodeSet.empty() && NonUniquedMDNodes.empty() &&
-           "Destroying all MDNodes didn't empty the Context's sets.");
     // Destroy MDStrings.
     for (StringMap<MDString*>::iterator I = MDStringCache.begin(),
            E = MDStringCache.end(); I != E; ++I) {
diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index faf83e6588..a08c45480b 100644
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -110,10 +110,8 @@ MDNode::MDNode(LLVMContext &C, Value *const *Vals, unsigned NumVals,
 MDNode::~MDNode() {
   assert((getSubclassDataFromValue() & DestroyFlag) != 0 &&
          "Not being destroyed through destroy()?");
-  LLVMContextImpl *pImpl = getType()->getContext().pImpl;
-  if (isNotUniqued()) {
-    pImpl->NonUniquedMDNodes.erase(this);
-  } else {
+  if (!isNotUniqued()) {
+    LLVMContextImpl *pImpl = getType()->getContext().pImpl;
     pImpl->MDNodeSet.RemoveNode(this);
   }
 
@@ -259,10 +257,12 @@ void MDNode::Profile(FoldingSetNodeID &ID) const {
     ID.AddPointer(getOperand(i));
 }
 
-void MDNode::setIsNotUniqued() {
-  setValueSubclassData(getSubclassDataFromValue() | NotUniquedBit);
-  LLVMContextImpl *pImpl = getType()->getContext().pImpl;
-  pImpl->NonUniquedMDNodes.insert(this);
+// replaceAllOperandsWithNull - This is used while destroying llvm context to 
+// gracefully delete all nodes. This method replaces all operands with null.
+void MDNode::replaceAllOperandsWithNull() {
+  for (MDNodeOperand *Op = getOperandPtr(this, 0), *E = Op+NumOperands;
+       Op != E; ++Op)
+    replaceOperand(Op, 0);
 }
 
 // Replace value from this node's operand list.