[llvm-commits] [llvm] r96609 - in /llvm/trunk: include/llvm/Metadata.h lib/VMCore/LLVMContextImpl.h lib/VMCore/Metadata.cpp

[Devang Patel]

Author: dpatel
Date: Thu Feb 18 14:53:16 2010
New Revision: 96609

URL: http://llvm.org/viewvc/llvm-project?rev=96609&view=rev
Log:
Destroy MDNodes gracefully while deleting llvm context.

Modified:
    llvm/trunk/include/llvm/Metadata.h
    llvm/trunk/lib/VMCore/LLVMContextImpl.h
    llvm/trunk/lib/VMCore/Metadata.cpp

Modified: llvm/trunk/include/llvm/Metadata.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Metadata.h?rev=96609&r1=96608&r2=96609&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Metadata.h (original)
+++ llvm/trunk/include/llvm/Metadata.h Thu Feb 18 14:53:16 2010
@@ -75,6 +75,7 @@
   MDNode(const MDNode &);                // DO NOT IMPLEMENT
   void operator=(const MDNode &);        // DO NOT IMPLEMENT
   friend class MDNodeOperand;
+  friend class LLVMContextImpl;
 
   /// NumOperands - This many 'MDNodeOperand' items are co-allocated onto the
   /// end of this MDNode.
@@ -106,6 +107,9 @@
   // Replace each instance of F from the operand list of this node with T.
   void replaceOperand(MDNodeOperand *Op, Value *NewVal);
   ~MDNode();
+    // replaceAllOperandsWithNull - This is used while destroying llvm context to 
+  // gracefully delete all nodes. This method replaces all operands with null.
+  void replaceAllOperandsWithNull();
 
 protected:
   explicit MDNode(LLVMContext &C, Value *const *Vals, unsigned NumVals,

Modified: llvm/trunk/lib/VMCore/LLVMContextImpl.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/LLVMContextImpl.h?rev=96609&r1=96608&r2=96609&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/LLVMContextImpl.h (original)
+++ llvm/trunk/lib/VMCore/LLVMContextImpl.h Thu Feb 18 14:53:16 2010
@@ -229,13 +229,23 @@
       if (I->second->use_empty())
         delete I->second;
     }
-    MDNodeSet.clear();
     AlwaysOpaqueTy->dropRef();
     for (OpaqueTypesTy::iterator I = OpaqueTypes.begin(), E = OpaqueTypes.end();
         I != E; ++I) {
       (*I)->AbstractTypeUsers.clear();
       delete *I;
     }
+    // Destroy MDNode operands first.
+    for (FoldingSetIterator<MDNode> I = MDNodeSet.begin(), E = MDNodeSet.end();
+         I != E;) {
+      MDNode *N = &(*I);
+      ++I;
+      N->replaceAllOperandsWithNull();
+    }
+    while (!MDNodeSet.empty()) {
+      MDNode *N = &(*MDNodeSet.begin());
+      N->destroy();
+    }
   }
 };
 

Modified: llvm/trunk/lib/VMCore/Metadata.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Metadata.cpp?rev=96609&r1=96608&r2=96609&view=diff

==============================================================================
--- llvm/trunk/lib/VMCore/Metadata.cpp (original)
+++ llvm/trunk/lib/VMCore/Metadata.cpp Thu Feb 18 14:53:16 2010
@@ -257,6 +257,13 @@
     ID.AddPointer(getOperand(i));
 }
 
+// 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.
 void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) {