Added special treatment of serializing NULL pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43357 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/Deserialize.h

@@ -86,6 +86,10 @@ public:
   template <typename T>
   inline T* ReadOwnedPtr() {    
     unsigned PtrId = ReadInt();
+
+    if (PtrId == 0)
+      return NULL;
+    
     T* x = SerializeTrait<T>::Materialize(*this);
     RegisterPtr(PtrId,x);
     return x;

include/llvm/Bitcode/Serialize.h

@@ -47,7 +47,7 @@ public:
   template <typename T>
   void EmitOwnedPtr(T* ptr) {
     EmitPtr(ptr);
-    SerializeTrait<T>::Emit(*this,*ptr);    
+    if (ptr) SerializeTrait<T>::Emit(*this,*ptr);
   }
 
   void Flush() { if (inRecord()) EmitRecord(); }

lib/Bitcode/Reader/Deserialize.cpp

@@ -103,6 +103,11 @@ void Deserializer::RegisterPtr(unsigned PtrId,void* Ptr) {
 void Deserializer::ReadPtr(void*& PtrRef) {
   unsigned PtrId = ReadInt();
   
+  if (PtrId == 0) {
+    PtrRef = NULL;
+    return;
+  }  
+  
   BPatchEntry& E = BPatchMap[PtrId];
   
   if (E.Ptr == NULL) {

lib/Bitcode/Writer/Serialize.cpp

@@ -58,10 +58,13 @@ void Serializer::EmitCStr(const char* s) {
 }
 
 unsigned Serializer::getPtrId(void* ptr) {
+  if (!ptr)
+    return 0;
+  
   MapTy::iterator I = PtrMap.find(ptr);
   
   if (I == PtrMap.end()) {
-    unsigned id = PtrMap.size();
+    unsigned id = PtrMap.size()+1;
     PtrMap[ptr] = id;
     return id;
   }