Debug Info: Move a helper function getTypeIdentifier from DIBuilder to be part

of DIType.
    
Implement DIType::generateRef to return a type reference. This function will be
used in setContaintingType and in DIBuilder to generete the type reference.
    
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190188 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/DebugInfo.h

@@ -155,20 +155,6 @@ namespace llvm {
   template <>
   DITypeRef DIDescriptor::getFieldAs<DITypeRef>(unsigned Elt) const;
 
-  /// Represents reference to a DIType, abstracts over direct and
-  /// identifier-based metadata type references.
-  class DITypeRef {
-    template <typename DescTy>
-    friend DescTy DIDescriptor::getFieldAs(unsigned Elt) const;
-
-    /// TypeVal can be either a MDNode or a MDString, in the latter,
-    /// MDString specifies the type identifier.
-    const Value *TypeVal;
-    explicit DITypeRef(const Value *V);
-  public:
-    DIType resolve(const DITypeIdentifierMap &Map) const;
-  };
-
   /// DISubrange - This is used to represent ranges, for array bounds.
   class DISubrange : public DIDescriptor {
     friend class DIDescriptor;
@@ -285,12 +271,32 @@ namespace llvm {
     /// isUnsignedDIType - Return true if type encoding is unsigned.
     bool isUnsignedDIType();
 
+    /// Generate a reference to this DIType. Uses the type identifier instead
+    /// of the actual MDNode if possible, to help type uniquing.
+    DITypeRef generateRef();
+
     /// replaceAllUsesWith - Replace all uses of debug info referenced by
     /// this descriptor.
     void replaceAllUsesWith(DIDescriptor &D);
     void replaceAllUsesWith(MDNode *D);
   };
 
+  /// Represents reference to a DIType, abstracts over direct and
+  /// identifier-based metadata type references.
+  class DITypeRef {
+    template <typename DescTy>
+    friend DescTy DIDescriptor::getFieldAs(unsigned Elt) const;
+    friend DITypeRef DIType::generateRef();
+
+    /// TypeVal can be either a MDNode or a MDString, in the latter,
+    /// MDString specifies the type identifier.
+    const Value *TypeVal;
+    explicit DITypeRef(const Value *V);
+  public:
+    DIType resolve(const DITypeIdentifierMap &Map) const;
+    operator Value *() const { return const_cast<Value*>(TypeVal); }
+  };
+
   /// DIBasicType - A basic type, like 'int' or 'float'.
   class DIBasicType : public DIType {
   public:

lib/IR/DIBuilder.cpp

@@ -75,18 +75,6 @@ void DIBuilder::finalize() {
   DIType(TempImportedModules).replaceAllUsesWith(IMs);
 }
 
-/// Use the type identifier instead of the actual MDNode if possible,
-/// to help type uniquing. This function returns the identifier if it
-/// exists for the given type, otherwise returns the MDNode.
-static Value *getTypeIdentifier(DIType T) {
-  if (!T.isCompositeType())
-    return T;
-  DICompositeType DTy(T);
-  if (!DTy.getIdentifier())
-    return T;
-  return DTy.getIdentifier();
-}
-
 /// getNonCompileUnitScope - If N is compile unit return NULL otherwise return
 /// N.
 static MDNode *getNonCompileUnitScope(MDNode *N) {
@@ -334,7 +322,7 @@ DIDerivedType DIBuilder::createMemberPointerType(DIType PointeeTy,
     ConstantInt::get(Type::getInt64Ty(VMContext), 0), // Offset
     ConstantInt::get(Type::getInt32Ty(VMContext), 0), // Flags
     PointeeTy,
-    getTypeIdentifier(Base)
+    Base.generateRef()
   };
   return DIDerivedType(MDNode::get(VMContext, Elts));
 }

lib/IR/DebugInfo.cpp

@@ -707,6 +707,17 @@ void DICompositeType::addMember(DIDescriptor D) {
   setTypeArray(DIArray(MDNode::get(DbgNode->getContext(), M)));
 }
 
+/// Generate a reference to this DIType. Uses the type identifier instead
+/// of the actual MDNode if possible, to help type uniquing.
+DITypeRef DIType::generateRef() {
+  if (!isCompositeType())
+    return DITypeRef(*this);
+  DICompositeType DTy(DbgNode);
+  if (!DTy.getIdentifier())
+    return DITypeRef(*this);
+  return DITypeRef(DTy.getIdentifier());
+}
+
 /// \brief Set the containing type.
 void DICompositeType::setContainingType(DICompositeType ContainingType) {
   TrackingVH<MDNode> N(*this);