convert CAZ, UndefValue, and CPN to use DenseMap's again, this time without
using OwningPtr.  OwningPtr would barf when the densemap had to reallocate,
which doesn't appear to happen on the regression test suite, but obviously
happens in real life :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148700 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 9657cd2..e9b433b 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -993,18 +993,21 @@
 //===----------------------------------------------------------------------===//
 //                      Factory Function Implementation
 
-ConstantAggregateZero* ConstantAggregateZero::get(Type* Ty) {
+ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
   assert((Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()) &&
          "Cannot create an aggregate zero of non-aggregate type!");
   
-  LLVMContextImpl *pImpl = Ty->getContext().pImpl;
-  return pImpl->AggZeroConstants.getOrCreate(Ty, 0);
+  ConstantAggregateZero *&Entry = Ty->getContext().pImpl->CAZConstants[Ty];
+  if (Entry == 0)
+    Entry = new ConstantAggregateZero(Ty);
+  
+  return Entry;
 }
 
 /// destroyConstant - Remove the constant from the constant table...
 ///
 void ConstantAggregateZero::destroyConstant() {
-  getType()->getContext().pImpl->AggZeroConstants.remove(this);
+  getContext().pImpl->CAZConstants.erase(getType());
   destroyConstantImpl();
 }
 
@@ -1112,13 +1115,18 @@
 //
 
 ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
-  return Ty->getContext().pImpl->NullPtrConstants.getOrCreate(Ty, 0);
+  ConstantPointerNull *&Entry = Ty->getContext().pImpl->CPNConstants[Ty];
+  if (Entry == 0)
+    Entry = new ConstantPointerNull(Ty);
+  
+  return Entry;
 }
 
 // destroyConstant - Remove the constant from the constant table...
 //
 void ConstantPointerNull::destroyConstant() {
-  getType()->getContext().pImpl->NullPtrConstants.remove(this);
+  getContext().pImpl->CPNConstants.erase(getType());
+  // Free the constant and any dangling references to it.
   destroyConstantImpl();
 }
 
@@ -1127,13 +1135,18 @@
 //
 
 UndefValue *UndefValue::get(Type *Ty) {
-  return Ty->getContext().pImpl->UndefValueConstants.getOrCreate(Ty, 0);
+  UndefValue *&Entry = Ty->getContext().pImpl->UVConstants[Ty];
+  if (Entry == 0)
+    Entry = new UndefValue(Ty);
+  
+  return Entry;
 }
 
 // destroyConstant - Remove the constant from the constant table.
 //
 void UndefValue::destroyConstant() {
-  getType()->getContext().pImpl->UndefValueConstants.remove(this);
+  // Free the constant and any dangling references to it.
+  getContext().pImpl->UVConstants.erase(getType());
   destroyConstantImpl();
 }
 
diff --git a/lib/VMCore/ConstantsContext.h b/lib/VMCore/ConstantsContext.h
index 4ee4296..4bdeaa7 100644
--- a/lib/VMCore/ConstantsContext.h
+++ b/lib/VMCore/ConstantsContext.h
@@ -477,13 +477,6 @@
   }
 };
 
-// ConstantAggregateZero does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<ConstantAggregateZero, Type, ValType> {
-  static ConstantAggregateZero *create(Type *Ty, const ValType &V){
-    return new ConstantAggregateZero(Ty);
-  }
-};
 
 template<>
 struct ConstantKeyData<ConstantVector> {
@@ -498,14 +491,6 @@
 };
 
 template<>
-struct ConstantKeyData<ConstantAggregateZero> {
-  typedef char ValType;
-  static ValType getValType(ConstantAggregateZero *C) {
-    return 0;
-  }
-};
-
-template<>
 struct ConstantKeyData<ConstantArray> {
   typedef std::vector<Constant*> ValType;
   static ValType getValType(ConstantArray *CA) {
@@ -529,37 +514,6 @@
   }
 };
 
-// ConstantPointerNull does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<ConstantPointerNull, PointerType, ValType> {
-  static ConstantPointerNull *create(PointerType *Ty, const ValType &V){
-    return new ConstantPointerNull(Ty);
-  }
-};
-
-template<>
-struct ConstantKeyData<ConstantPointerNull> {
-  typedef char ValType;
-  static ValType getValType(ConstantPointerNull *C) {
-    return 0;
-  }
-};
-
-// UndefValue does not take extra "value" argument...
-template<class ValType>
-struct ConstantCreator<UndefValue, Type, ValType> {
-  static UndefValue *create(Type *Ty, const ValType &V) {
-    return new UndefValue(Ty);
-  }
-};
-
-template<>
-struct ConstantKeyData<UndefValue> {
-  typedef char ValType;
-  static ValType getValType(UndefValue *C) {
-    return 0;
-  }
-};
 
 template<>
 struct ConstantCreator<InlineAsm, PointerType, InlineAsmKeyType> {
diff --git a/lib/VMCore/LLVMContextImpl.cpp b/lib/VMCore/LLVMContextImpl.cpp
index b0dd680..2eaebac 100644
--- a/lib/VMCore/LLVMContextImpl.cpp
+++ b/lib/VMCore/LLVMContextImpl.cpp
@@ -58,6 +58,8 @@
   std::vector<Module*> Modules(OwnedModules.begin(), OwnedModules.end());
   DeleteContainerPointers(Modules);
   
+  // Free the constants.  This is important to do here to ensure that they are
+  // freed before the LeakDetector is torn down.
   std::for_each(ExprConstants.map_begin(), ExprConstants.map_end(),
                 DropReferences());
   std::for_each(ArrayConstants.map_begin(), ArrayConstants.map_end(),
@@ -70,9 +72,9 @@
   ArrayConstants.freeConstants();
   StructConstants.freeConstants();
   VectorConstants.freeConstants();
-  AggZeroConstants.freeConstants();
-  NullPtrConstants.freeConstants();
-  UndefValueConstants.freeConstants();
+  DeleteContainerSeconds(CAZConstants);
+  DeleteContainerSeconds(CPNConstants);
+  DeleteContainerSeconds(UVConstants);
   InlineAsms.freeConstants();
   DeleteContainerSeconds(IntConstants);
   DeleteContainerSeconds(FPConstants);
diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 30f9d46..f8abdf1 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -138,7 +138,7 @@
   // on Context destruction.
   SmallPtrSet<MDNode*, 1> NonUniquedMDNodes;
   
-  ConstantUniqueMap<char, char, Type, ConstantAggregateZero> AggZeroConstants;
+  DenseMap<Type*, ConstantAggregateZero*> CAZConstants;
 
   typedef ConstantUniqueMap<std::vector<Constant*>, ArrayRef<Constant*>,
     ArrayType, ConstantArray, true /*largekey*/> ArrayConstantsTy;
@@ -152,9 +152,9 @@
                             VectorType, ConstantVector> VectorConstantsTy;
   VectorConstantsTy VectorConstants;
   
-  ConstantUniqueMap<char, char, PointerType, ConstantPointerNull>
-    NullPtrConstants;
-  ConstantUniqueMap<char, char, Type, UndefValue> UndefValueConstants;
+  DenseMap<PointerType*, ConstantPointerNull*> CPNConstants;
+
+  DenseMap<Type*, UndefValue*> UVConstants;
   
   DenseMap<std::pair<Function*, BasicBlock*> , BlockAddress*> BlockAddresses;
   ConstantUniqueMap<ExprMapKeyType, const ExprMapKeyType&, Type, ConstantExpr>