Added typedef "SerializedPtrID" to represent the pointer handle written to disk

instead of just using "unsigned".  This gives us more flexibility in changing
the definition of the handle later, and is more self-documenting.

Added tracking of block stack in the Deserializer.  Now clients can query
if they are still within a block using the methods GetCurrentBlockLocation()
and FinishedBlock().

llvm-svn: 43903

llvm/include/llvm/Bitcode/Deserialize.h

@@ -55,12 +55,12 @@ class Deserializer {
     unsigned Raw;
     
   public:
-    BPKey(unsigned PtrId) : Raw(PtrId << 1) { assert (PtrId > 0); }
+    BPKey(SerializedPtrID PtrId) : Raw(PtrId << 1) { assert (PtrId > 0); }
     BPKey(unsigned code, unsigned) : Raw(code) {}
     
     void MarkFinal() { Raw |= 0x1; }
     bool hasFinalPtr() const { return Raw & 0x1 ? true : false; }
-    unsigned getID() const { return Raw >> 1; }
+    SerializedPtrID getID() const { return Raw >> 1; }
     
     static inline BPKey getEmptyKey() { return BPKey(0,0); }
     static inline BPKey getTombstoneKey() { return BPKey(1,0); }
@@ -75,16 +75,25 @@ class Deserializer {
   
   typedef llvm::DenseMap<BPKey,BPEntry,BPKey,BPEntry> MapTy;
 
+  //===----------------------------------------------------------===//
+  // Publicly visible types.
+  //===----------------------------------------------------------===//
+  
+public:  
+  typedef uint64_t Location;
+  
   //===----------------------------------------------------------===//
   // Internal data members.
   //===----------------------------------------------------------===//
 
+private:
   BitstreamReader& Stream;
   SmallVector<uint64_t,10> Record;
   unsigned RecIdx;
   BumpPtrAllocator Allocator;
   BPNode* FreeList;
   MapTy BPatchMap;
+  llvm::SmallVector<uint64_t,5> BlockLocs;
   
   //===----------------------------------------------------------===//
   // Public Interface.
@@ -96,6 +105,8 @@ public:
 
   uint64_t ReadInt();
   int64_t ReadSInt();
+  SerializedPtrID ReadPtrID() { return (SerializedPtrID) ReadInt(); }
+  
   
   bool ReadBool() {
     return ReadInt() ? true : false;
@@ -117,7 +128,7 @@ public:
 
   template <typename T>
   inline T* ReadOwnedPtr(bool AutoRegister = true) {
-    unsigned PtrID = ReadInt();    
+    SerializedPtrID PtrID = ReadPtrID();    
 
     if (!PtrID)
       return NULL;
@@ -139,8 +150,8 @@ public:
   void BatchReadOwnedPtrs(T1*& P1, T2*& P2,
                           bool A1=true, bool A2=true) {
 
-    unsigned ID1 = ReadInt();
-    unsigned ID2 = ReadInt();
+    SerializedPtrID ID1 = ReadPtrID();
+    SerializedPtrID ID2 = ReadPtrID();
 
     P1 = (ID1) ? SerializeTrait<T1>::Materialize(*this) : NULL;
     if (ID1 && A1) RegisterPtr(ID1,P1);
@@ -153,9 +164,9 @@ public:
   void BatchReadOwnedPtrs(T1*& P1, T2*& P2, T3*& P3,
                           bool A1=true, bool A2=true, bool A3=true) {
     
-    unsigned ID1 = ReadInt();
-    unsigned ID2 = ReadInt();
-    unsigned ID3 = ReadInt();
+    SerializedPtrID ID1 = ReadPtrID();
+    SerializedPtrID ID2 = ReadPtrID();
+    SerializedPtrID ID3 = ReadPtrID();
     
     P1 = (ID1) ? SerializeTrait<T1>::Materialize(*this) : NULL;
     if (ID1 && A1) RegisterPtr(ID1,P1);    
@@ -170,10 +181,10 @@ public:
   template <typename T>
   void BatchReadOwnedPtrs(unsigned NumPtrs, T** Ptrs, bool AutoRegister=true) {
     for (unsigned i = 0; i < NumPtrs; ++i)
-      reinterpret_cast<uintptr_t&>(Ptrs[i]) = ReadInt();
+      reinterpret_cast<SerializedPtrID&>(Ptrs[i]) = ReadPtrID();
     
     for (unsigned i = 0; i < NumPtrs; ++i) {
-      unsigned PtrID = reinterpret_cast<uintptr_t>(Ptrs[i]);
+      SerializedPtrID PtrID = reinterpret_cast<SerializedPtrID>(Ptrs[i]);
       T* p = PtrID ? SerializeTrait<T>::Materialize(*this) : NULL;
       
       if (PtrID && AutoRegister)
@@ -204,15 +215,28 @@ public:
     return *p;
   }
 
-  void RegisterPtr(unsigned PtrId, const void* Ptr);
+  void RegisterPtr(SerializedPtrID PtrId, const void* Ptr);
   
   void RegisterPtr(const void* Ptr) {
-    RegisterPtr(ReadInt(),Ptr);
+    RegisterPtr(ReadPtrID(),Ptr);
   }
   
-  bool AtEnd();
+  template<typename T>
+  void RegisterRef(const T& x) {
+    RegisterPtr(&x);
+  }
   
+  template<typename T>
+  void RegisterRef(SerializedPtrID PtrID, const T& x) {
+    RegisterPtr(PtrID,&x);
+  }  
+  
+  Location GetCurrentBlockLocation();
+  bool FinishedBlock(Location BlockLoc);
+  
+  bool AtEnd();
   bool inRecord();
+  
 private:
   void ReadRecord();  
   uintptr_t ReadInternalRefPtr();

llvm/include/llvm/Bitcode/SerializationFwd.h

@@ -20,6 +20,8 @@ class Serializer;
 class Deserializer;  
 template <typename T> struct SerializeTrait;  
 
+typedef unsigned SerializedPtrID;
+
 } // end namespace llvm
 
 #endif

llvm/include/llvm/Bitcode/Serialize.h

@@ -94,15 +94,16 @@ public:
       if (Ptrs[i]) SerializeTrait<T>::Emit(*this,*Ptrs[i]);
   }
     
-  void FlushRecord() { if (inRecord()) EmitRecord(); }
+  bool isRegistered(const void* p) const;
   
+  void FlushRecord() { if (inRecord()) EmitRecord(); }  
   void EnterBlock(unsigned BlockID = 8, unsigned CodeLen = 3);
   void ExitBlock();    
   
 private:
   void EmitRecord();
   inline bool inRecord() { return Record.size() > 0; }
-  unsigned getPtrId(const void* ptr);
+  SerializedPtrID getPtrId(const void* ptr);
 };
 
 } // end namespace llvm

llvm/lib/Bitcode/Reader/Deserialize.cpp

@@ -63,7 +63,7 @@ void Deserializer::ReadRecord() {
     Code = Stream.ReadCode();
   
     if (Code == bitc::ENTER_SUBBLOCK) {
-      // No known subblocks, always skip them.
+      BlockLocs.push_back(Stream.GetCurrentBitNo());
       unsigned id = Stream.ReadSubBlockID();
       Stream.EnterSubBlock(id);
       continue;
@@ -72,6 +72,7 @@ void Deserializer::ReadRecord() {
     if (Code == bitc::END_BLOCK) {      
       bool x = Stream.ReadBlockEnd();
       assert (!x && "Error at block end.");
+      BlockLocs.pop_back();
       continue;
     }
     
@@ -88,6 +89,26 @@ void Deserializer::ReadRecord() {
   assert (Record.size() > 0 || Stream.AtEndOfStream());
 }
 
+Deserializer::Location Deserializer::GetCurrentBlockLocation() {
+  if (!inRecord())
+    ReadRecord();
+  
+  assert (!BlockLocs.empty());
+  return BlockLocs.back();
+}
+
+bool Deserializer::FinishedBlock(Location BlockLoc) {
+  if (!inRecord())
+    ReadRecord();
+  
+  for (llvm::SmallVector<Location,5>::reverse_iterator
+       I=BlockLocs.rbegin(), E=BlockLocs.rend(); I!=E; ++I)
+    if (*I == BlockLoc)
+      return false;
+  
+  return true;
+}
+
 bool Deserializer::AtEnd() {
   if (inRecord())
     return false;
@@ -159,7 +180,7 @@ void Deserializer::RegisterPtr(unsigned PtrId, const void* Ptr) {
 }
 
 void Deserializer::ReadUIntPtr(uintptr_t& PtrRef, bool AllowBackpatch) {
-  unsigned PtrId = ReadInt();
+  SerializedPtrID PtrId = ReadPtrID();
   
   if (PtrId == 0) {
     PtrRef = 0;
@@ -194,7 +215,7 @@ void Deserializer::ReadUIntPtr(uintptr_t& PtrRef, bool AllowBackpatch) {
 }
 
 uintptr_t Deserializer::ReadInternalRefPtr() {
-  unsigned PtrId = ReadInt();
+  SerializedPtrID PtrId = ReadPtrID();
   
   assert (PtrId != 0 && "References cannot refer the NULL address.");
 

llvm/lib/Bitcode/Writer/Serialize.cpp

@@ -14,6 +14,10 @@
 #include "llvm/Bitcode/Serialize.h"
 #include "string.h"
 
+#ifdef DEBUG_BACKPATCH
+#include "llvm/Support/Streams.h"
+#endif
+
 using namespace llvm;
 
 Serializer::Serializer(BitstreamWriter& stream)
@@ -67,15 +71,13 @@ void Serializer::EmitCStr(const char* s, const char* end) {
     Record.push_back(*s);
     ++s;
   }
-
-  EmitRecord();
 }
 
 void Serializer::EmitCStr(const char* s) {
   EmitCStr(s,s+strlen(s));
 }
 
-unsigned Serializer::getPtrId(const void* ptr) {
+SerializedPtrID Serializer::getPtrId(const void* ptr) {
   if (!ptr)
     return 0;
   
@@ -83,12 +85,20 @@ unsigned Serializer::getPtrId(const void* ptr) {
   
   if (I == PtrMap.end()) {
     unsigned id = PtrMap.size()+1;
+#ifdef DEBUG_BACKPATCH
+    llvm::cerr << "Registered PTR: " << ptr << " => " << id << "\n";
+#endif
     PtrMap[ptr] = id;
     return id;
   }
   else return I->second;
 }
 
+bool Serializer::isRegistered(const void* ptr) const {
+  MapTy::const_iterator I = PtrMap.find(ptr);
+  return I != PtrMap.end();
+}
+
 
 #define INT_EMIT(TYPE)\
 void SerializeTrait<TYPE>::Emit(Serializer&S, TYPE X) { S.EmitInt(X); }