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

2 files changed, 38 insertions, 7 deletions

diff --git a/llvm/lib/Bitcode/Reader/Deserialize.cpp b/llvm/lib/Bitcode/Reader/Deserialize.cpp
index 99cb5d2e3ab..5d0c724b8b9 100644
--- a/llvm/lib/Bitcode/Reader/Deserialize.cpp
+++ b/llvm/lib/Bitcode/Reader/Deserialize.cpp
@@ -63,15 +63,16 @@ 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;
     }
 
-    if (Code == bitc::END_BLOCK) {
+    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.");
 
diff --git a/llvm/lib/Bitcode/Writer/Serialize.cpp b/llvm/lib/Bitcode/Writer/Serialize.cpp
index b97462b629e..3baf9ad59aa 100644
--- a/llvm/lib/Bitcode/Writer/Serialize.cpp
+++ b/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); }