Commit For New Tool: llvm-abcd (Analysis of ByteCode Dumper). This tool

will (eventually) provide statistical analysis of bytecode files as well
as the ability to dump them in a low level format (slot numbers not
resolved). The purpose of this is to aid in the Type!=Value change of
bug 122. With this initial release, llvm-abcd merely dumps out the
bytecode. However, the infrastructure for separating bytecode parsing from
handling the parsing events is in place. The style chosen is similar to
SAX XML parsing where a handler object is called to handlign the parsing
events. This probably isn't useful to anyone but me right now as there is
no analysis yet, and the dumper doesn't work on every bytecode file. It
will probably be useful by the end of this week. Note that there is some
duplication of code from the bytecode reader.  This was done to eliminate
errors from being introduced in the reader and to minimize the impact to
other LLVM developers. At some point, the Analyzer and the Reader will be
integrated to use the same infrastructure. Also, sorry for the minor change
to Instruction.h but I just couldn't bring myself to write code that
depends on Instruction internals.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14048 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bytecode/Analyzer.h

@@ -0,0 +1,97 @@
+//===-- llvm/Bytecode/Analyzer.h - Analyzer for bytecode files --*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This functionality is implemented by the lib/Bytecode/Analysis library.
+// This library is used to read VM bytecode files from an iostream and print
+// out a diagnostic analysis of the contents of the file. It is intended for
+// three uses: (a) understanding the bytecode format, (b) ensuring correctness
+// of bytecode format, (c) statistical analysis of generated bytecode files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BYTECODE_ANALYZER_H
+#define LLVM_BYTECODE_ANALYZER_H
+
+#include <string>
+#include <map>
+
+namespace llvm {
+
+/// This structure is used to contain the output of the Bytecode Analysis 
+/// library. It simply contains fields to hold each item of the analysis 
+/// results.
+/// @brief Bytecode Analysis results structure
+struct BytecodeAnalysis {
+  unsigned byteSize;            ///< The size of the bytecode file in bytes
+  unsigned numTypes;        ///< The number of types
+  unsigned numValues;       ///< The number of values
+  unsigned numFunctions;    ///< The number of functions defined
+  unsigned numConstants;    ///< The number of constants
+  unsigned numGlobalVars;   ///< The number of global variables
+  unsigned numInstructions; ///< The number of instructions in all functions
+  unsigned numBasicBlocks;  ///< The number of BBs in all functions
+  unsigned numOperands;     ///< The number of BBs in all functions
+  unsigned maxTypeSlot;     ///< The maximum slot number for types
+  unsigned maxValueSlot;    ///< The maximum slot number for values
+  double   density;         ///< Density of file (bytes/defs) 
+
+  /// A structure that contains various pieces of information related to
+  /// an analysis of a single function.
+  struct BytecodeFunctionInfo {
+    unsigned byteSize;        ///< The size of the function in bytecode bytes
+    unsigned numInstructions; ///< The number of instructions in the function
+    unsigned numBasicBlocks;  ///< The number of basic blocks in the function
+    unsigned numOperands;     ///< The number of operands in the function
+    double density;           ///< Density of function
+    double vbrEffectiveness;  ///< Effectiveness of variable bit rate encoding.
+    ///< This is the average number of bytes per unsigned value written in the
+    ///< vbr encoding. A "perfect" score of 1.0 means all vbr values were 
+    ///< encoded in one byte. A score between 1.0 and 4.0 means that some
+    ///< savings were achieved. A score of 4.0 means vbr didn't help. A score
+    ///< greater than 4.0 means vbr negatively impacted size of the file.
+  };
+
+  /// A mapping of function names to the collected information about the 
+  /// function.
+  std::map<std::string,BytecodeFunctionInfo> FunctionInfo; 
+
+  /// Flags for what should be done
+  bool dumpBytecode;
+};
+
+/// This function is the main entry point into the bytecode analysis library. It
+/// allows you to simply provide a \P filename and storage for the \P Results 
+/// that will be filled in with the analysis results.
+/// @brief Analyze contents of a bytecode File
+void AnalyzeBytecodeFile(
+      const std::string& Filename, ///< The name of the bytecode file to read
+      BytecodeAnalysis& Results,   ///< The results of the analysis
+      std::string* ErrorStr = 0    ///< Errors, if any.
+    );
+
+/// This function is an alternate entry point into the bytecode analysis
+/// library. It allows you to provide an arbitrary memory buffer which is
+/// assumed to contain a complete bytecode file. The \P Buffer is analyzed and
+/// the \P Results are filled in.
+/// @brief Analyze contents of a bytecode buffer.
+void AnalyzeBytecodeBuffer(
+       const unsigned char* Buffer, ///< Pointer to start of bytecode buffer
+       unsigned BufferSize,         ///< Size of the bytecode buffer
+       BytecodeAnalysis& Results,   ///< The results of the analysis
+       std::string* ErrorStr = 0    ///< Errors, if any.
+     );
+
+/// This function prints the contents of rhe BytecodeAnalysis structure in
+/// a human legible form.
+/// @brief Print BytecodeAnalysis structure to an ostream
+void PrintBytecodeAnalysis(BytecodeAnalysis& bca, std::ostream& Out );
+
+} // End llvm namespace
+
+#endif

include/llvm/Instruction.h

@@ -87,9 +87,14 @@ public:
   }
   static const char* getOpcodeName(unsigned OpCode);
 
-  inline bool isTerminator() const {   // Instance of TerminatorInst?
-    return iType >= TermOpsBegin && iType < TermOpsEnd;
+  static inline bool isTerminator(unsigned OpCode) {
+    return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
   }
+
+  inline bool isTerminator() const {   // Instance of TerminatorInst?
+    return isTerminator(iType);
+  }
+
   inline bool isBinaryOp() const {
     return iType >= BinaryOpsBegin && iType < BinaryOpsEnd;
   }

lib/Bytecode/Analyzer/Analyzer.cpp

@@ -0,0 +1,242 @@
+//===-- BytecodeHandler.cpp - Parsing Handler -------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeHandler class that gets called by the
+//  AbstractBytecodeParser when parsing events occur.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+
+using namespace llvm;
+
+
+namespace {
+
+class AnalyzerHandler : public BytecodeHandler {
+public:
+  bool handleError(const std::string& str )
+  {
+    return false;
+  }
+
+  void handleStart()
+  {
+  }
+
+  void handleFinish()
+  {
+  }
+
+  void handleModuleBegin(const std::string& id)
+  {
+  }
+
+  void handleModuleEnd(const std::string& id)
+  {
+  }
+
+  void handleVersionInfo(
+    unsigned char RevisionNum,        ///< Byte code revision number
+    Module::Endianness Endianness,    ///< Endianness indicator
+    Module::PointerSize PointerSize   ///< PointerSize indicator
+  )
+  {
+  }
+
+  void handleModuleGlobalsBegin()
+  {
+  }
+
+  void handleGlobalVariable( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes ///< The linkage type of the GV
+  )
+  {
+  }
+
+  void handleInitializedGV( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes,///< The linkage type of the GV
+    unsigned initSlot         ///< Slot number of GV's initializer
+  )
+  {
+  }
+
+  virtual void handleType( const Type* Ty ) 
+  {
+  }
+
+  void handleFunctionDeclaration( 
+    const Type* FuncType      ///< The type of the function
+  )
+  {
+  }
+
+  void handleModuleGlobalsEnd()
+  {
+  }
+
+  void handleCompactionTableBegin()
+  {
+  }
+
+  void handleCompactionTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries
+  )
+  {
+  }
+
+  void handleCompactionTableType( 
+    unsigned i, 
+    unsigned TypSlot, 
+    const Type* 
+  )
+  {
+  }
+
+  void handleCompactionTableValue( 
+    unsigned i, 
+    unsigned ValSlot, 
+    const Type* 
+  )
+  {
+  }
+
+  void handleCompactionTableEnd()
+  {
+  }
+
+  void handleSymbolTableBegin()
+  {
+  }
+
+  void handleSymbolTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries, 
+    const Type* Typ
+  )
+  {
+  }
+
+  void handleSymbolTableType( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+  }
+
+  void handleSymbolTableValue( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+  }
+
+  void handleSymbolTableEnd()
+  {
+  }
+
+  void handleFunctionBegin(
+    const Type* FType, 
+    GlobalValue::LinkageTypes linkage 
+  )
+  {
+  }
+
+  void handleFunctionEnd(
+    const Type* FType
+  )
+  {
+  }
+
+  void handleBasicBlockBegin(
+    unsigned blocknum
+  )
+  {
+  }
+
+  bool handleInstruction(
+    unsigned Opcode, 
+    const Type* iType, 
+    std::vector<unsigned>& Operands
+  )
+  {
+    return false;
+  }
+
+  void handleBasicBlockEnd(unsigned blocknum)
+  {
+  }
+
+  void handleGlobalConstantsBegin()
+  {
+  }
+
+  void handleConstantExpression( 
+      unsigned Opcode, 
+      const Type* Typ, 
+      std::vector<std::pair<const Type*,unsigned> > ArgVec 
+    )
+  {
+  }
+
+  void handleConstantValue( Constant * c )
+  {
+  }
+
+  void handleConstantArray( 
+	  const ArrayType* AT, 
+	  std::vector<unsigned>& Elements )
+  {
+  }
+
+  void handleConstantStruct(
+	const StructType* ST,
+	std::vector<unsigned>& ElementSlots)
+  {
+  }
+
+  void handleConstantPointer(
+	const PointerType* PT, unsigned Slot)
+  {
+  }
+
+  void handleConstantString( const ConstantArray* CA ) 
+  {
+  }
+
+
+  void handleGlobalConstantsEnd()
+  {
+  }
+
+};
+
+}
+
+void llvm::BytecodeAnalyzer::AnalyzeBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+)
+{
+  AnalyzerHandler TheHandler;
+  AbstractBytecodeParser TheParser(&TheHandler);
+  TheParser.ParseBytecode( Buf, Length, ModuleID );
+  TheParser.ParseAllFunctionBodies();
+}
+
+// vim: sw=2

lib/Bytecode/Analyzer/AnalyzerInternals.h

@@ -0,0 +1,65 @@
+//===-- ReaderInternals.h - Definitions internal to the reader --*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines various stuff that is used by the bytecode reader.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ANALYZER_INTERNALS_H
+#define ANALYZER_INTERNALS_H
+
+#include "Parser.h"
+#include "llvm/Bytecode/Analyzer.h"
+
+// Enable to trace to figure out what the heck is going on when parsing fails
+//#define TRACE_LEVEL 10
+//#define DEBUG_OUTPUT
+
+#if TRACE_LEVEL    // ByteCodeReading_TRACEr
+#define BCR_TRACE(n, X) \
+    if (n < TRACE_LEVEL) std::cerr << std::string(n*2, ' ') << X
+#else
+#define BCR_TRACE(n, X)
+#endif
+
+namespace llvm {
+
+class BytecodeAnalyzer {
+  BytecodeAnalyzer(const BytecodeAnalyzer &);  // DO NOT IMPLEMENT
+  void operator=(const BytecodeAnalyzer &);  // DO NOT IMPLEMENT
+public:
+  BytecodeAnalyzer() { }
+  ~BytecodeAnalyzer() { }
+
+  void AnalyzeBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  );
+
+  void DumpBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  );
+
+  void dump() const {
+    std::cerr << "BytecodeParser instance!\n";
+  }
+private:
+  BytecodeAnalysis TheAnalysis;
+};
+
+} // End llvm namespace
+
+#endif
+
+// vim: sw=2

lib/Bytecode/Analyzer/AnalyzerWrappers.cpp

@@ -0,0 +1,208 @@
+//===- AnalyzerWrappers.cpp - Analyze bytecode from file or buffer  -------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file implements loading and analysis of a bytecode file and analyzing a
+// bytecode buffer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bytecode/Analyzer.h"
+#include "AnalyzerInternals.h"
+#include "Support/FileUtilities.h"
+#include "Support/StringExtras.h"
+#include "Config/unistd.h"
+#include <cerrno>
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// BytecodeFileAnalyzer - Analyze from an mmap'able file descriptor.
+//
+
+namespace {
+  /// BytecodeFileAnalyzer - parses a bytecode file from a file
+  class BytecodeFileAnalyzer : public BytecodeAnalyzer {
+  private:
+    unsigned char *Buffer;
+    unsigned Length;
+
+    BytecodeFileAnalyzer(const BytecodeFileAnalyzer&); // Do not implement
+    void operator=(const BytecodeFileAnalyzer &BFR); // Do not implement
+
+  public:
+    BytecodeFileAnalyzer(const std::string &Filename, BytecodeAnalysis& bca);
+    ~BytecodeFileAnalyzer();
+  };
+}
+
+static std::string ErrnoMessage (int savedErrNum, std::string descr) {
+   return ::strerror(savedErrNum) + std::string(", while trying to ") + descr;
+}
+
+BytecodeFileAnalyzer::BytecodeFileAnalyzer(const std::string &Filename, 
+	                                   BytecodeAnalysis& bca) {
+  Buffer = (unsigned char*)ReadFileIntoAddressSpace(Filename, Length);
+  if (Buffer == 0)
+    throw "Error reading file '" + Filename + "'.";
+
+  try {
+    // Parse the bytecode we mmapped in
+    if ( bca.dumpBytecode ) 
+      DumpBytecode(Buffer, Length, bca, Filename);
+    AnalyzeBytecode(Buffer, Length, bca, Filename);
+  } catch (...) {
+    UnmapFileFromAddressSpace(Buffer, Length);
+    throw;
+  }
+}
+
+BytecodeFileAnalyzer::~BytecodeFileAnalyzer() {
+  // Unmmap the bytecode...
+  UnmapFileFromAddressSpace(Buffer, Length);
+}
+
+//===----------------------------------------------------------------------===//
+// BytecodeBufferAnalyzer - Read from a memory buffer
+//
+
+namespace {
+  /// BytecodeBufferAnalyzer - parses a bytecode file from a buffer
+  ///
+  class BytecodeBufferAnalyzer : public BytecodeAnalyzer {
+  private:
+    const unsigned char *Buffer;
+    bool MustDelete;
+
+    BytecodeBufferAnalyzer(const BytecodeBufferAnalyzer&); // Do not implement
+    void operator=(const BytecodeBufferAnalyzer &BFR);   // Do not implement
+
+  public:
+    BytecodeBufferAnalyzer(const unsigned char *Buf, unsigned Length,
+	                   BytecodeAnalysis& bca, const std::string &ModuleID);
+    ~BytecodeBufferAnalyzer();
+
+  };
+}
+
+BytecodeBufferAnalyzer::BytecodeBufferAnalyzer(const unsigned char *Buf,
+					       unsigned Length,
+					       BytecodeAnalysis& bca,
+					       const std::string &ModuleID) {
+  // If not aligned, allocate a new buffer to hold the bytecode...
+  const unsigned char *ParseBegin = 0;
+  if ((intptr_t)Buf & 3) {
+    Buffer = new unsigned char[Length+4];
+    unsigned Offset = 4 - ((intptr_t)Buffer & 3);   // Make sure it's aligned
+    ParseBegin = Buffer + Offset;
+    memcpy((unsigned char*)ParseBegin, Buf, Length);    // Copy it over
+    MustDelete = true;
+  } else {
+    // If we don't need to copy it over, just use the caller's copy
+    ParseBegin = Buffer = Buf;
+    MustDelete = false;
+  }
+  try {
+    if ( bca.dumpBytecode ) 
+      DumpBytecode(ParseBegin, Length, bca, ModuleID);
+    AnalyzeBytecode(ParseBegin, Length, bca, ModuleID);
+  } catch (...) {
+    if (MustDelete) delete [] Buffer;
+    throw;
+  }
+}
+
+BytecodeBufferAnalyzer::~BytecodeBufferAnalyzer() {
+  if (MustDelete) delete [] Buffer;
+}
+
+//===----------------------------------------------------------------------===//
+//  BytecodeStdinAnalyzer - Read bytecode from Standard Input
+//
+
+namespace {
+  /// BytecodeStdinAnalyzer - parses a bytecode file from stdin
+  /// 
+  class BytecodeStdinAnalyzer : public BytecodeAnalyzer {
+  private:
+    std::vector<unsigned char> FileData;
+    unsigned char *FileBuf;
+
+    BytecodeStdinAnalyzer(const BytecodeStdinAnalyzer&); // Do not implement
+    void operator=(const BytecodeStdinAnalyzer &BFR);  // Do not implement
+
+  public:
+    BytecodeStdinAnalyzer(BytecodeAnalysis& bca);
+  };
+}
+
+BytecodeStdinAnalyzer::BytecodeStdinAnalyzer(BytecodeAnalysis& bca ) {
+  int BlockSize;
+  unsigned char Buffer[4096*4];
+
+  // Read in all of the data from stdin, we cannot mmap stdin...
+  while ((BlockSize = ::read(0 /*stdin*/, Buffer, 4096*4))) {
+    if (BlockSize == -1)
+      throw ErrnoMessage(errno, "read from standard input");
+    
+    FileData.insert(FileData.end(), Buffer, Buffer+BlockSize);
+  }
+
+  if (FileData.empty())
+    throw std::string("Standard Input empty!");
+
+  FileBuf = &FileData[0];
+  if (bca.dumpBytecode)
+    DumpBytecode(&FileData[0], FileData.size(), bca, "<stdin>");
+  AnalyzeBytecode(FileBuf, FileData.size(), bca, "<stdin>");
+}
+
+//===----------------------------------------------------------------------===//
+// Wrapper functions
+//===----------------------------------------------------------------------===//
+
+// AnalyzeBytecodeFile - analyze one file
+void llvm::AnalyzeBytecodeFile(const std::string &Filename, 
+                               BytecodeAnalysis& bca,
+                               std::string *ErrorStr) 
+{
+  try {
+    if ( Filename != "-" )
+      BytecodeFileAnalyzer bfa(Filename,bca);
+    else
+      BytecodeStdinAnalyzer bsa(bca);
+  } catch (std::string &err) {
+    if (ErrorStr) *ErrorStr = err;
+  }
+}
+
+// AnalyzeBytecodeBuffer - analyze a buffer
+void llvm::AnalyzeBytecodeBuffer(
+       const unsigned char* Buffer, ///< Pointer to start of bytecode buffer
+       unsigned BufferSize,         ///< Size of the bytecode buffer
+       BytecodeAnalysis& Results,   ///< The results of the analysis
+       std::string* ErrorStr        ///< Errors, if any.
+     ) 
+{
+  try {
+    BytecodeBufferAnalyzer(Buffer, BufferSize, Results, "<buffer>" );
+  } catch (std::string& err ) {
+    if ( ErrorStr) *ErrorStr = err;
+  }
+}
+
+
+/// This function prints the contents of rhe BytecodeAnalysis structure in
+/// a human legible form.
+/// @brief Print BytecodeAnalysis structure to an ostream
+void llvm::PrintBytecodeAnalysis(BytecodeAnalysis& bca, std::ostream& Out )
+{
+  Out << "Not Implemented Yet.\n";
+}
+
+// vim: sw=2

lib/Bytecode/Analyzer/BytecodeHandler.cpp

@@ -0,0 +1,220 @@
+//===-- BytecodeHandler.cpp - Parsing Handler -------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeHandler class that gets called by the
+//  AbstractBytecodeParser when parsing events occur.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BytecodeHandler.h"
+
+using namespace llvm;
+
+bool BytecodeHandler::handleError(const std::string& str )
+{
+  return false;
+}
+
+void BytecodeHandler::handleStart()
+{
+}
+
+void BytecodeHandler::handleFinish()
+{
+}
+
+void BytecodeHandler::handleModuleBegin(const std::string& id)
+{
+}
+
+void BytecodeHandler::handleModuleEnd(const std::string& id)
+{
+}
+
+void BytecodeHandler::handleVersionInfo(
+  unsigned char RevisionNum,        ///< Byte code revision number
+  Module::Endianness Endianness,    ///< Endianness indicator
+  Module::PointerSize PointerSize   ///< PointerSize indicator
+)
+{
+}
+
+void BytecodeHandler::handleModuleGlobalsBegin()
+{
+}
+
+void BytecodeHandler::handleGlobalVariable( 
+  const Type* ElemType,     ///< The type of the global variable
+  bool isConstant,          ///< Whether the GV is constant or not
+  GlobalValue::LinkageTypes ///< The linkage type of the GV
+)
+{
+}
+
+void BytecodeHandler::handleInitializedGV( 
+  const Type* ElemType,     ///< The type of the global variable
+  bool isConstant,          ///< Whether the GV is constant or not
+  GlobalValue::LinkageTypes,///< The linkage type of the GV
+  unsigned initSlot         ///< Slot number of GV's initializer
+)
+{
+}
+
+void BytecodeHandler::handleType( const Type* Ty ) 
+{
+}
+
+void BytecodeHandler::handleFunctionDeclaration( 
+  const Type* FuncType      ///< The type of the function
+)
+{
+}
+
+void BytecodeHandler::handleModuleGlobalsEnd()
+{
+}
+
+void BytecodeHandler::handleCompactionTableBegin()
+{
+}
+
+void BytecodeHandler::handleCompactionTablePlane( 
+  unsigned Ty, 
+  unsigned NumEntries
+)
+{
+}
+
+void BytecodeHandler::handleCompactionTableType( 
+  unsigned i, 
+  unsigned TypSlot, 
+  const Type* 
+)
+{
+}
+
+void BytecodeHandler::handleCompactionTableValue( 
+  unsigned i, 
+  unsigned ValSlot, 
+  const Type* 
+)
+{
+}
+
+void BytecodeHandler::handleCompactionTableEnd()
+{
+}
+
+void BytecodeHandler::handleSymbolTableBegin()
+{
+}
+
+void BytecodeHandler::handleSymbolTablePlane( 
+  unsigned Ty, 
+  unsigned NumEntries, 
+  const Type* Typ
+)
+{
+}
+
+void BytecodeHandler::handleSymbolTableType( 
+  unsigned i, 
+  unsigned slot, 
+  const std::string& name 
+)
+{
+}
+
+void BytecodeHandler::handleSymbolTableValue( 
+  unsigned i, 
+  unsigned slot, 
+  const std::string& name 
+)
+{
+}
+
+void BytecodeHandler::handleSymbolTableEnd()
+{
+}
+
+void BytecodeHandler::handleFunctionBegin(
+  const Type* FType, 
+  GlobalValue::LinkageTypes linkage 
+)
+{
+}
+
+void BytecodeHandler::handleFunctionEnd(
+  const Type* FType
+)
+{
+}
+
+void BytecodeHandler::handleBasicBlockBegin(
+  unsigned blocknum
+)
+{
+}
+
+bool BytecodeHandler::handleInstruction(
+  unsigned Opcode, 
+  const Type* iType, 
+  std::vector<unsigned>& Operands
+)
+{
+  return false;
+}
+
+void BytecodeHandler::handleBasicBlockEnd(unsigned blocknum)
+{
+}
+
+void BytecodeHandler::handleGlobalConstantsBegin()
+{
+}
+
+void BytecodeHandler::handleConstantExpression( 
+    unsigned Opcode, 
+    const Type* Typ, 
+    std::vector<std::pair<const Type*,unsigned> > ArgVec 
+  )
+{
+}
+
+void BytecodeHandler::handleConstantValue( Constant * c )
+{
+}
+
+void BytecodeHandler::handleConstantArray( 
+        const ArrayType* AT, 
+        std::vector<unsigned>& Elements )
+{
+}
+
+void BytecodeHandler::handleConstantStruct(
+      const StructType* ST,
+      std::vector<unsigned>& ElementSlots)
+{
+}
+
+void BytecodeHandler::handleConstantPointer(
+      const PointerType* PT, unsigned Slot)
+{
+}
+
+void BytecodeHandler::handleConstantString( const ConstantArray* CA ) 
+{
+}
+
+
+void BytecodeHandler::handleGlobalConstantsEnd()
+{
+}
+
+// vim: sw=2

lib/Bytecode/Analyzer/BytecodeHandler.h

@@ -0,0 +1,247 @@
+//===-- BytecodeHandler.h - Parsing Handler ---------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeHandler class that gets called by the
+//  AbstractBytecodeParser when parsing events occur.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef BYTECODE_HANDLER_H
+#define BYTECODE_HANDLER_H
+
+#include "llvm/Module.h"
+#include "llvm/GlobalValue.h"
+#include <vector>
+
+namespace llvm {
+
+class ArrayType;
+class StructType;
+class PointerType;
+class ConstantArray;
+
+/// This class provides the interface for the handling bytecode events during
+/// parsing. The methods on this interface are invoked by the 
+/// AbstractBytecodeParser as it discovers the content of a bytecode stream. 
+/// This class provides a a clear separation of concerns between recognizing 
+/// the semantic units of a bytecode file and deciding what to do with them. 
+/// The AbstractBytecodeParser recognizes the content of the bytecode file and
+/// calls the BytecodeHandler methods to determine what should be done. This
+/// arrangement allows Bytecode files to be read and handled for a number of
+/// purposes simply by creating a subclass of BytecodeHandler. None of the
+/// parsing details need to be understood, only the meaning of the calls
+/// made on this interface.
+/// 
+/// Another paradigm that uses this design pattern is the XML SAX Parser. The
+/// ContentHandler for SAX plays the same role as the BytecodeHandler here.
+/// @brief Handle Bytecode Parsing Events
+class BytecodeHandler {
+
+/// @name Constructors And Operators
+/// @{
+public:
+  /// @brief Default constructor (empty)
+  BytecodeHandler() {}
+  /// @brief Virtual destructor (empty)
+  virtual ~BytecodeHandler() {}
+
+private:
+  BytecodeHandler(const BytecodeHandler &);  // DO NOT IMPLEMENT
+  void operator=(const BytecodeHandler &);  // DO NOT IMPLEMENT
+
+/// @}
+/// @name Handler Methods
+/// @{
+public:
+
+  /// This method is called whenever the parser detects an error in the
+  /// bytecode formatting. Returning true will cause the parser to keep 
+  /// going, however this is inadvisable in most cases. Returning false will
+  /// cause the parser to throw the message as a std::string.
+  /// @brief Handle parsing errors.
+  virtual bool handleError(const std::string& str );
+
+  /// This method is called at the beginning of a parse before anything is
+  /// read in order to give the handler a chance to initialize.
+  /// @brief Handle the start of a bytecode parse
+  virtual void handleStart();
+
+  /// This method is called at the end of a parse after everything has been
+  /// read in order to give the handler a chance to terminate.
+  /// @brief Handle the end of a bytecode parse
+  virtual void handleFinish();
+
+  /// This method is called at the start of a module to indicate that a
+  /// module is being parsed.
+  /// @brief Handle the start of a module.
+  virtual void handleModuleBegin(const std::string& id);
+
+  /// This method is called at the end of a module to indicate that the module
+  /// previously being parsed has concluded.
+  /// @brief Handle the end of a module.
+  virtual void handleModuleEnd(const std::string& id);
+
+  /// This method is called once the version information has been parsed. It 
+  /// provides the information about the version of the bytecode file being 
+  /// read.
+  /// @brief Handle the bytecode prolog
+  virtual void handleVersionInfo(
+    unsigned char RevisionNum,        ///< Byte code revision number
+    Module::Endianness Endianness,    ///< Endianness indicator
+    Module::PointerSize PointerSize   ///< PointerSize indicator
+  );
+
+  /// This method is called at the start of a module globals block which
+  /// contains the global variables and the function placeholders
+  virtual void handleModuleGlobalsBegin();
+
+  /// This method is called when a non-initialized global variable is 
+  /// recognized. Its type, constness, and linkage type are provided.
+  /// @brief Handle a non-initialized global variable
+  virtual void handleGlobalVariable( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes ///< The linkage type of the GV
+  );
+
+  /// This method is called when an initialized global variable is recognized.
+  /// Its type constness, linkage type, and the slot number of the initializer
+  /// are provided.
+  /// @brief Handle an intialized global variable.
+  virtual void handleInitializedGV( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes,///< The linkage type of the GV
+    unsigned initSlot         ///< Slot number of GV's initializer
+  );
+
+  /// This method is called when a new type is recognized. The type is 
+  /// converted from the bytecode and passed to this method.
+  /// @brief Handle a type
+  virtual void handleType( const Type* Ty );
+
+  /// This method is called when the function prototype for a function is
+  /// encountered in the module globals block.
+  virtual void handleFunctionDeclaration( 
+    const Type* FuncType      ///< The type of the function
+  );
+
+  /// This method is called at the end of the module globals block.
+  /// @brief Handle end of module globals block.
+  virtual void handleModuleGlobalsEnd();
+
+  /// This method is called at the beginning of a compaction table.
+  /// @brief Handle start of compaction table.
+  virtual void handleCompactionTableBegin();
+  virtual void handleCompactionTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries
+  );
+
+  virtual void handleCompactionTableType( 
+    unsigned i, 
+    unsigned TypSlot, 
+    const Type* 
+  );
+
+  virtual void handleCompactionTableValue( 
+    unsigned i, 
+    unsigned ValSlot, 
+    const Type* 
+  );
+
+  virtual void handleCompactionTableEnd();
+
+  virtual void handleSymbolTableBegin();
+
+  virtual void handleSymbolTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries, 
+    const Type* Ty 
+  );
+
+  virtual void handleSymbolTableType( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  );
+
+  virtual void handleSymbolTableValue( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  );
+
+  virtual void handleSymbolTableEnd();
+
+  virtual void handleFunctionBegin(
+    const Type* FType, 
+    GlobalValue::LinkageTypes linkage 
+  );
+
+  virtual void handleFunctionEnd(
+    const Type* FType
+  );
+
+  virtual void handleBasicBlockBegin(
+    unsigned blocknum
+  );
+
+  /// This method is called for each instruction that is parsed. 
+  /// @returns true if the instruction is a block terminating instruction
+  /// @brief Handle an instruction
+  virtual bool handleInstruction(
+    unsigned Opcode, 
+    const Type* iType, 
+    std::vector<unsigned>& Operands
+  );
+
+  /// This method is called for each block that is parsed.
+  virtual void handleBasicBlockEnd(unsigned blocknum);
+  /// This method is called at the start of the global constants block.
+  /// @brief Handle start of global constants block.
+  virtual void handleGlobalConstantsBegin();
+
+  virtual void handleConstantExpression( 
+    unsigned Opcode, 
+    const Type* Typ, 
+    std::vector<std::pair<const Type*,unsigned> > ArgVec 
+  );
+
+  virtual void handleConstantArray( 
+    const ArrayType* AT, 
+    std::vector<unsigned>& ElementSlots
+  );
+
+  virtual void handleConstantStruct(
+    const StructType* ST,
+    std::vector<unsigned>& ElementSlots
+  );
+
+  virtual void handleConstantPointer(
+    const PointerType* PT,
+    unsigned Slot
+  );
+
+  virtual void handleConstantString(
+    const ConstantArray* CA
+  );
+
+  virtual void handleConstantValue( Constant * c );
+  virtual void handleGlobalConstantsEnd();
+
+/// @}
+
+};
+
+} // End llvm namespace
+
+#endif
+
+// vim: sw=2

lib/Bytecode/Analyzer/Dumper.cpp

@@ -0,0 +1,311 @@
+//===-- BytecodeDumper.cpp - Parsing Handler --------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeDumper class that gets called by the
+//  AbstractBytecodeParser when parsing events occur. It merely dumps the
+//  information presented to it from the parser.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+#include "llvm/Constant.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instruction.h"
+#include "llvm/Type.h"
+
+using namespace llvm;
+
+namespace {
+
+class BytecodeDumper : public llvm::BytecodeHandler {
+public:
+
+  virtual bool handleError(const std::string& str )
+  {
+    std::cout << "ERROR: " << str << "\n";
+    return true;
+  }
+
+  virtual void handleStart()
+  {
+    std::cout << "Bytecode {\n";
+  }
+
+  virtual void handleFinish()
+  {
+    std::cout << "} End Bytecode\n";
+  }
+
+  virtual void handleModuleBegin(const std::string& id)
+  {
+    std::cout << "  Module " << id << " {\n";
+  }
+
+  virtual void handleModuleEnd(const std::string& id)
+  {
+    std::cout << "  } End Module " << id << "\n";
+  }
+
+  virtual void handleVersionInfo(
+    unsigned char RevisionNum,        ///< Byte code revision number
+    Module::Endianness Endianness,    ///< Endianness indicator
+    Module::PointerSize PointerSize   ///< PointerSize indicator
+  )
+  {
+    std::cout << "    RevisionNum: " << int(RevisionNum) 
+	      << " Endianness: " << Endianness
+	      << " PointerSize: " << PointerSize << "\n";
+  }
+
+  virtual void handleModuleGlobalsBegin()
+  {
+    std::cout << "    BLOCK: ModuleGlobalInfo {\n";
+  }
+
+  virtual void handleGlobalVariable( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes Linkage ///< The linkage type of the GV
+  )
+  {
+    std::cout << "      GV: Uninitialized, " 
+	     << ( isConstant? "Constant, " : "Variable, ")
+	     << " Linkage=" << Linkage << " Type=" 
+	     << ElemType->getDescription() << "\n"; 
+  }
+
+  virtual void handleInitializedGV( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes Linkage,///< The linkage type of the GV
+    unsigned initSlot         ///< Slot number of GV's initializer
+  )
+  {
+    std::cout << "      GV: Initialized, " 
+	     << ( isConstant? "Constant, " : "Variable, ")
+	     << " Linkage=" << Linkage << " Type=" 
+	     << ElemType->getDescription()
+	     << " InitializerSlot=" << initSlot << "\n"; 
+  }
+
+  virtual void handleType( const Type* Ty ) 
+  {
+    std::cout << "      Type: " << Ty->getDescription() << "\n";
+  }
+
+  virtual void handleFunctionDeclaration( const Type* FuncType )
+  {
+    std::cout << "      Function: " << FuncType->getDescription() << "\n";
+  }
+
+  virtual void handleModuleGlobalsEnd()
+  {
+    std::cout << "    } END BLOCK: ModuleGlobalInfo\n";
+  }
+
+  void handleCompactionTableBegin()
+  {
+    std::cout << "    BLOCK: CompactionTable {\n";
+  }
+
+  virtual void handleCompactionTablePlane( unsigned Ty, unsigned NumEntries )
+  {
+    std::cout << "      Plane: Ty=" << Ty << " Size=" << NumEntries << "\n";
+  }
+
+  virtual void handleCompactionTableType( 
+    unsigned i, 
+    unsigned TypSlot, 
+    const Type* Ty
+  )
+  {
+    std::cout << "        Type: " << i << " Slot:" << TypSlot 
+	      << " is " << Ty->getDescription() << "\n"; 
+  }
+
+  virtual void handleCompactionTableValue( 
+    unsigned i, 
+    unsigned ValSlot, 
+    const Type* Ty 
+  )
+  {
+    std::cout << "        Value: " << i << " Slot:" << ValSlot 
+	      << " is " << Ty->getDescription() << "\n"; 
+  }
+
+  virtual void handleCompactionTableEnd()
+  {
+    std::cout << "    } END BLOCK: CompactionTable\n";
+  }
+
+  virtual void handleSymbolTableBegin()
+  {
+    std::cout << "    BLOCK: SymbolTable {\n";
+  }
+
+  virtual void handleSymbolTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries, 
+    const Type* Typ
+  )
+  {
+    std::cout << "      Plane: Ty=" << Ty << " Size=" << NumEntries
+	      << " Type: " << Typ->getDescription() << "\n"; 
+  }
+
+  virtual void handleSymbolTableType( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+    std::cout << "        Type " << i << " Slot=" << slot
+	      << " Name: " << name << "\n"; 
+  }
+
+  virtual void handleSymbolTableValue( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+    std::cout << "        Value " << i << " Slot=" << slot
+	      << " Name: " << name << "\n";
+  }
+
+  virtual void handleSymbolTableEnd()
+  {
+    std::cout << "    } END BLOCK: SymbolTable\n";
+  }
+
+  virtual void handleFunctionBegin(
+    const Type* FType, 
+    GlobalValue::LinkageTypes linkage 
+  )
+  {
+    std::cout << "    BLOCK: Function {\n";
+    std::cout << "      Linkage: " << linkage << "\n";
+    std::cout << "      Type: " << FType->getDescription() << "\n";
+  }
+
+  virtual void handleFunctionEnd(
+    const Type* FType
+  )
+  {
+    std::cout << "    } END BLOCK: Function\n";
+  }
+
+  virtual void handleBasicBlockBegin(
+    unsigned blocknum
+  )
+  {
+    std::cout << "      BLOCK: BasicBlock #" << blocknum << "{\n";
+  }
+
+  virtual bool handleInstruction(
+    unsigned Opcode, 
+    const Type* iType, 
+    std::vector<unsigned>& Operands
+  )
+  {
+    std::cout << "        INST: OpCode=" 
+	      << Instruction::getOpcodeName(Opcode) << " Type=" 
+	      << iType->getDescription() << "\n";
+    for ( unsigned i = 0; i < Operands.size(); ++i ) 
+      std::cout << "          Op#" << i << " Slot=" << Operands[i] << "\n";
+    
+    return Instruction::isTerminator(Opcode); 
+  }
+
+  virtual void handleBasicBlockEnd(unsigned blocknum)
+  {
+    std::cout << "      } END BLOCK: BasicBlock #" << blocknum << "{\n";
+  }
+
+  virtual void handleGlobalConstantsBegin()
+  {
+    std::cout << "    BLOCK: GlobalConstants {\n";
+  }
+
+  virtual void handleConstantExpression( 
+      unsigned Opcode, 
+      const Type* Typ, 
+      std::vector<std::pair<const Type*,unsigned> > ArgVec 
+    )
+  {
+    std::cout << "      EXPR: " << Instruction::getOpcodeName(Opcode)
+	      << " Type=" << Typ->getDescription() << "\n";
+    for ( unsigned i = 0; i < ArgVec.size(); ++i ) 
+      std::cout << "        Arg#" << i << " Type=" 
+	<< ArgVec[i].first->getDescription() << " Slot=" 
+	<< ArgVec[i].second << "\n";
+  }
+
+  virtual void handleConstantValue( Constant * c )
+  {
+    std::cout << "      VALUE: ";
+    c->print(std::cout);
+    std::cout << "\n";
+  }
+
+  virtual void handleConstantArray( 
+	  const ArrayType* AT, 
+	  std::vector<unsigned>& Elements )
+  {
+    std::cout << "      ARRAY: " << AT->getDescription() << "\n";
+    for ( unsigned i = 0; i < Elements.size(); ++i ) 
+      std::cout << "        #" << i << " Slot=" << Elements[i] << "\n";
+  }
+
+  virtual void handleConstantStruct(
+	const StructType* ST,
+	std::vector<unsigned>& Elements)
+  {
+    std::cout << "      STRUC: " << ST->getDescription() << "\n";
+    for ( unsigned i = 0; i < Elements.size(); ++i ) 
+      std::cout << "        #" << i << " Slot=" << Elements[i] << "\n";
+  }
+
+  virtual void handleConstantPointer(
+	const PointerType* PT, unsigned Slot)
+  {
+    std::cout << "      POINT: " << PT->getDescription() 
+	      << " Slot=" << Slot << "\n";
+  }
+
+  virtual void handleConstantString( const ConstantArray* CA ) 
+  {
+    std::cout << "      STRNG: ";
+    CA->print(std::cout); 
+    std::cout << "\n";
+  }
+
+  virtual void handleGlobalConstantsEnd()
+  {
+    std::cout << "    } END BLOCK: GlobalConstants\n";
+  }
+};
+
+}
+
+void BytecodeAnalyzer::DumpBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  )
+{
+  BytecodeDumper TheHandler;
+  AbstractBytecodeParser TheParser(&TheHandler);
+  TheParser.ParseBytecode( Buf, Length, ModuleID );
+  TheParser.ParseAllFunctionBodies();
+}
+
+// vim: sw=2

lib/Bytecode/Analyzer/Makefile

@@ -0,0 +1,13 @@
+##===- lib/Bytecode/Reader/Makefile ------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file was developed by the LLVM research group and is distributed under
+# the University of Illinois Open Source License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../../..
+LIBRARYNAME = bcanalyzer
+
+include $(LEVEL)/Makefile.common
+

lib/Bytecode/Analyzer/Parser.cpp

@@ -0,0 +1,877 @@
+//===- Reader.cpp - Code to read bytecode files ---------------------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This library implements the functionality defined in llvm/Bytecode/Reader.h
+//
+// Note that this library should be as fast as possible, reentrant, and 
+// threadsafe!!
+//
+// TODO: Allow passing in an option to ignore the symbol table
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+#include "llvm/Module.h"
+#include "llvm/Bytecode/Format.h"
+#include "Support/StringExtras.h"
+#include <iostream>
+#include <sstream>
+
+using namespace llvm;
+
+#define PARSE_ERROR(inserters) \
+  { \
+    std::ostringstream errormsg; \
+    errormsg << inserters; \
+    if ( ! handler->handleError( errormsg.str() ) ) \
+      throw std::string(errormsg.str()); \
+  }
+
+const Type *AbstractBytecodeParser::getType(unsigned ID) {
+  //cerr << "Looking up Type ID: " << ID << "\n";
+
+  if (ID < Type::FirstDerivedTyID)
+    if (const Type *T = Type::getPrimitiveType((Type::PrimitiveID)ID))
+      return T;   // Asked for a primitive type...
+
+  // Otherwise, derived types need offset...
+  ID -= Type::FirstDerivedTyID;
+
+  if (!CompactionTypeTable.empty()) {
+    if (ID >= CompactionTypeTable.size())
+      PARSE_ERROR("Type ID out of range for compaction table!");
+    return CompactionTypeTable[ID];
+  }
+
+  // Is it a module-level type?
+  if (ID < ModuleTypes.size())
+    return ModuleTypes[ID].get();
+
+  // Nope, is it a function-level type?
+  ID -= ModuleTypes.size();
+  if (ID < FunctionTypes.size())
+    return FunctionTypes[ID].get();
+
+  PARSE_ERROR("Illegal type reference!");
+  return Type::VoidTy;
+}
+
+bool AbstractBytecodeParser::ParseInstruction(BufPtr& Buf, BufPtr EndBuf,
+                                      std::vector<unsigned> &Operands) {
+  Operands.clear();
+  unsigned iType = 0;
+  unsigned Opcode = 0;
+  unsigned Op = read(Buf, EndBuf);
+
+  // bits   Instruction format:        Common to all formats
+  // --------------------------
+  // 01-00: Opcode type, fixed to 1.
+  // 07-02: Opcode
+  Opcode    = (Op >> 2) & 63;
+  Operands.resize((Op >> 0) & 03);
+
+  switch (Operands.size()) {
+  case 1:
+    // bits   Instruction format:
+    // --------------------------
+    // 19-08: Resulting type plane
+    // 31-20: Operand #1 (if set to (2^12-1), then zero operands)
+    //
+    iType   = (Op >>  8) & 4095;
+    Operands[0] = (Op >> 20) & 4095;
+    if (Operands[0] == 4095)    // Handle special encoding for 0 operands...
+      Operands.resize(0);
+    break;
+  case 2:
+    // bits   Instruction format:
+    // --------------------------
+    // 15-08: Resulting type plane
+    // 23-16: Operand #1
+    // 31-24: Operand #2  
+    //
+    iType   = (Op >>  8) & 255;
+    Operands[0] = (Op >> 16) & 255;
+    Operands[1] = (Op >> 24) & 255;
+    break;
+  case 3:
+    // bits   Instruction format:
+    // --------------------------
+    // 13-08: Resulting type plane
+    // 19-14: Operand #1
+    // 25-20: Operand #2
+    // 31-26: Operand #3
+    //
+    iType   = (Op >>  8) & 63;
+    Operands[0] = (Op >> 14) & 63;
+    Operands[1] = (Op >> 20) & 63;
+    Operands[2] = (Op >> 26) & 63;
+    break;
+  case 0:
+    Buf -= 4;  // Hrm, try this again...
+    Opcode = read_vbr_uint(Buf, EndBuf);
+    Opcode >>= 2;
+    iType = read_vbr_uint(Buf, EndBuf);
+
+    unsigned NumOperands = read_vbr_uint(Buf, EndBuf);
+    Operands.resize(NumOperands);
+
+    if (NumOperands == 0)
+      PARSE_ERROR("Zero-argument instruction found; this is invalid.");
+
+    for (unsigned i = 0; i != NumOperands; ++i)
+      Operands[i] = read_vbr_uint(Buf, EndBuf);
+    align32(Buf, EndBuf);
+    break;
+  }
+
+  return handler->handleInstruction(Opcode, getType(iType), Operands);
+}
+
+/// ParseBasicBlock - In LLVM 1.0 bytecode files, we used to output one
+/// basicblock at a time.  This method reads in one of the basicblock packets.
+void AbstractBytecodeParser::ParseBasicBlock(BufPtr &Buf,
+                                            BufPtr EndBuf,
+                                            unsigned BlockNo) {
+  handler->handleBasicBlockBegin( BlockNo );
+
+  std::vector<unsigned> Args;
+  bool is_terminating = false;
+  while (Buf < EndBuf)
+    is_terminating = ParseInstruction(Buf, EndBuf, Args);
+
+  if ( ! is_terminating )
+    PARSE_ERROR(
+      "Failed to recognize instruction as terminating at end of block");
+
+  handler->handleBasicBlockEnd( BlockNo );
+}
+
+
+/// ParseInstructionList - Parse all of the BasicBlock's & Instruction's in the
+/// body of a function.  In post 1.0 bytecode files, we no longer emit basic
+/// block individually, in order to avoid per-basic-block overhead.
+unsigned AbstractBytecodeParser::ParseInstructionList( BufPtr &Buf, BufPtr EndBuf) {
+  unsigned BlockNo = 0;
+  std::vector<unsigned> Args;
+
+  while (Buf < EndBuf) {
+    handler->handleBasicBlockBegin( BlockNo );
+
+    // Read instructions into this basic block until we get to a terminator
+    bool is_terminating = false;
+    while (Buf < EndBuf && !is_terminating )
+	is_terminating = ParseInstruction(Buf, EndBuf, Args ) ;
+
+    if (!is_terminating)
+      PARSE_ERROR( "Non-terminated basic block found!");
+
+    handler->handleBasicBlockEnd( BlockNo );
+    ++BlockNo;
+  }
+  return BlockNo;
+}
+
+void AbstractBytecodeParser::ParseSymbolTable(BufPtr &Buf, BufPtr EndBuf) {
+  handler->handleSymbolTableBegin();
+
+  while (Buf < EndBuf) {
+    // Symtab block header: [num entries][type id number]
+    unsigned NumEntries = read_vbr_uint(Buf, EndBuf);
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    const Type *Ty = getType(Typ);
+
+    handler->handleSymbolTablePlane( Typ, NumEntries, Ty );
+
+    for (unsigned i = 0; i != NumEntries; ++i) {
+      // Symtab entry: [def slot #][name]
+      unsigned slot = read_vbr_uint(Buf, EndBuf);
+      std::string Name = read_str(Buf, EndBuf);
+
+      if (Typ == Type::TypeTyID)
+        handler->handleSymbolTableType( i, slot, Name );
+      else
+	handler->handleSymbolTableValue( i, slot, Name );
+    }
+  }
+
+  if (Buf > EndBuf) 
+    PARSE_ERROR("Tried to read past end of buffer while reading symbol table.");
+
+  handler->handleSymbolTableEnd();
+}
+
+void AbstractBytecodeParser::ParseFunctionLazily(BufPtr &Buf, BufPtr EndBuf) {
+  if (FunctionSignatureList.empty())
+    throw std::string("FunctionSignatureList empty!");
+
+  const Type *FType = FunctionSignatureList.back();
+  FunctionSignatureList.pop_back();
+
+  // Save the information for future reading of the function
+  LazyFunctionLoadMap[FType] = LazyFunctionInfo(Buf, EndBuf);
+  // Pretend we've `parsed' this function
+  Buf = EndBuf;
+}
+
+void AbstractBytecodeParser::ParseNextFunction(Type* FType) {
+  // Find {start, end} pointers and slot in the map. If not there, we're done.
+  LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.find(FType);
+
+  // Make sure we found it
+  if ( Fi == LazyFunctionLoadMap.end() ) {
+    PARSE_ERROR("Unrecognized function of type " << FType->getDescription());
+    return;
+  }
+
+  BufPtr Buf = Fi->second.Buf;
+  BufPtr EndBuf = Fi->second.EndBuf;
+  assert(Fi->first == FType);
+
+  LazyFunctionLoadMap.erase(Fi);
+
+  this->ParseFunctionBody( FType, Buf, EndBuf );
+}
+
+void AbstractBytecodeParser::ParseFunctionBody(const Type* FType, 
+                                               BufPtr &Buf, BufPtr EndBuf ) {
+
+  GlobalValue::LinkageTypes Linkage = GlobalValue::ExternalLinkage;
+
+  unsigned LinkageType = read_vbr_uint(Buf, EndBuf);
+  switch (LinkageType) {
+  case 0: Linkage = GlobalValue::ExternalLinkage; break;
+  case 1: Linkage = GlobalValue::WeakLinkage; break;
+  case 2: Linkage = GlobalValue::AppendingLinkage; break;
+  case 3: Linkage = GlobalValue::InternalLinkage; break;
+  case 4: Linkage = GlobalValue::LinkOnceLinkage; break;
+  default:
+    PARSE_ERROR("Invalid linkage type for Function.");
+    Linkage = GlobalValue::InternalLinkage;
+    break;
+  }
+
+  handler->handleFunctionBegin(FType,Linkage);
+
+  // Keep track of how many basic blocks we have read in...
+  unsigned BlockNum = 0;
+  bool InsertedArguments = false;
+
+  while (Buf < EndBuf) {
+    unsigned Type, Size;
+    BufPtr OldBuf = Buf;
+    readBlock(Buf, EndBuf, Type, Size);
+
+    switch (Type) {
+    case BytecodeFormat::ConstantPool:
+      ParseConstantPool(Buf, Buf+Size, FunctionTypes );
+      break;
+
+    case BytecodeFormat::CompactionTable:
+      ParseCompactionTable(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::BasicBlock:
+      ParseBasicBlock(Buf, Buf+Size, BlockNum++);
+      break;
+
+    case BytecodeFormat::InstructionList:
+      if (BlockNum) 
+	PARSE_ERROR("InstructionList must come before basic blocks!");
+      BlockNum = ParseInstructionList(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::SymbolTable:
+      ParseSymbolTable(Buf, Buf+Size );
+      break;
+
+    default:
+      Buf += Size;
+      if (OldBuf > Buf)
+	PARSE_ERROR("Wrapped around reading bytecode");
+      break;
+    }
+
+    // Malformed bc file if read past end of block.
+    align32(Buf, EndBuf);
+  }
+
+  handler->handleFunctionEnd(FType);
+
+  // Clear out function-level types...
+  FunctionTypes.clear();
+  CompactionTypeTable.clear();
+}
+
+void AbstractBytecodeParser::ParseAllFunctionBodies() {
+  LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.begin();
+  LazyFunctionMap::iterator Fe = LazyFunctionLoadMap.end();
+
+  while ( Fi != Fe ) {
+    const Type* FType = Fi->first;
+    this->ParseFunctionBody(FType, Fi->second.Buf, Fi->second.EndBuf);
+  }
+}
+
+void AbstractBytecodeParser::ParseCompactionTable(BufPtr &Buf, BufPtr End) {
+
+  handler->handleCompactionTableBegin();
+
+  while (Buf != End) {
+    unsigned NumEntries = read_vbr_uint(Buf, End);
+    unsigned Ty;
+
+    if ((NumEntries & 3) == 3) {
+      NumEntries >>= 2;
+      Ty = read_vbr_uint(Buf, End);
+    } else {
+      Ty = NumEntries >> 2;
+      NumEntries &= 3;
+    }
+
+    handler->handleCompactionTablePlane( Ty, NumEntries );
+
+    if (Ty == Type::TypeTyID) {
+      for (unsigned i = 0; i != NumEntries; ++i) {
+	unsigned TypeSlot = read_vbr_uint(Buf,End);
+        const Type *Typ = getGlobalTableType(TypeSlot);
+	handler->handleCompactionTableType( i, TypeSlot, Typ );
+      }
+    } else {
+      const Type *Typ = getType(Ty);
+      // Push the implicit zero
+      for (unsigned i = 0; i != NumEntries; ++i) {
+	unsigned ValSlot = read_vbr_uint(Buf, End);
+	handler->handleCompactionTableValue( i, ValSlot, Typ );
+      }
+    }
+  }
+  handler->handleCompactionTableEnd();
+}
+
+const Type *AbstractBytecodeParser::ParseTypeConstant(const unsigned char *&Buf,
+					      const unsigned char *EndBuf) {
+  unsigned PrimType = read_vbr_uint(Buf, EndBuf);
+
+  const Type *Val = 0;
+  if ((Val = Type::getPrimitiveType((Type::PrimitiveID)PrimType)))
+    return Val;
+  
+  switch (PrimType) {
+  case Type::FunctionTyID: {
+    const Type *RetType = getType(read_vbr_uint(Buf, EndBuf));
+
+    unsigned NumParams = read_vbr_uint(Buf, EndBuf);
+
+    std::vector<const Type*> Params;
+    while (NumParams--)
+      Params.push_back(getType(read_vbr_uint(Buf, EndBuf)));
+
+    bool isVarArg = Params.size() && Params.back() == Type::VoidTy;
+    if (isVarArg) Params.pop_back();
+
+    Type* result = FunctionType::get(RetType, Params, isVarArg);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::ArrayTyID: {
+    unsigned ElTyp = read_vbr_uint(Buf, EndBuf);
+    const Type *ElementType = getType(ElTyp);
+
+    unsigned NumElements = read_vbr_uint(Buf, EndBuf);
+
+    BCR_TRACE(5, "Array Type Constant #" << ElTyp << " size=" 
+              << NumElements << "\n");
+    Type* result =  ArrayType::get(ElementType, NumElements);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::StructTyID: {
+    std::vector<const Type*> Elements;
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    while (Typ) {         // List is terminated by void/0 typeid
+      Elements.push_back(getType(Typ));
+      Typ = read_vbr_uint(Buf, EndBuf);
+    }
+
+    Type* result = StructType::get(Elements);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::PointerTyID: {
+    unsigned ElTyp = read_vbr_uint(Buf, EndBuf);
+    BCR_TRACE(5, "Pointer Type Constant #" << ElTyp << "\n");
+    Type* result = PointerType::get(getType(ElTyp));
+    handler->handleType( result );
+    return result;
+  }
+
+  case Type::OpaqueTyID: {
+    Type* result = OpaqueType::get();
+    handler->handleType( result );
+    return result;
+  }
+
+  default:
+    PARSE_ERROR("Don't know how to deserialize primitive type" << PrimType << "\n");
+    return Val;
+  }
+}
+
+// ParseTypeConstants - We have to use this weird code to handle recursive
+// types.  We know that recursive types will only reference the current slab of
+// values in the type plane, but they can forward reference types before they
+// have been read.  For example, Type #0 might be '{ Ty#1 }' and Type #1 might
+// be 'Ty#0*'.  When reading Type #0, type number one doesn't exist.  To fix
+// this ugly problem, we pessimistically insert an opaque type for each type we
+// are about to read.  This means that forward references will resolve to
+// something and when we reread the type later, we can replace the opaque type
+// with a new resolved concrete type.
+//
+void AbstractBytecodeParser::ParseTypeConstants(const unsigned char *&Buf,
+                                        const unsigned char *EndBuf,
+					TypeListTy &Tab,
+					unsigned NumEntries) {
+  assert(Tab.size() == 0 && "should not have read type constants in before!");
+
+  // Insert a bunch of opaque types to be resolved later...
+  Tab.reserve(NumEntries);
+  for (unsigned i = 0; i != NumEntries; ++i)
+    Tab.push_back(OpaqueType::get());
+
+  // Loop through reading all of the types.  Forward types will make use of the
+  // opaque types just inserted.
+  //
+  for (unsigned i = 0; i != NumEntries; ++i) {
+    const Type *NewTy = ParseTypeConstant(Buf, EndBuf), *OldTy = Tab[i].get();
+    if (NewTy == 0) throw std::string("Couldn't parse type!");
+    BCR_TRACE(4, "#" << i << ": Read Type Constant: '" << NewTy <<
+              "' Replacing: " << OldTy << "\n");
+
+    // Don't insertValue the new type... instead we want to replace the opaque
+    // type with the new concrete value...
+    //
+
+    // Refine the abstract type to the new type.  This causes all uses of the
+    // abstract type to use NewTy.  This also will cause the opaque type to be
+    // deleted...
+    //
+    cast<DerivedType>(const_cast<Type*>(OldTy))->refineAbstractTypeTo(NewTy);
+
+    // This should have replace the old opaque type with the new type in the
+    // value table... or with a preexisting type that was already in the system
+    assert(Tab[i] != OldTy && "refineAbstractType didn't work!");
+  }
+
+  BCR_TRACE(5, "Resulting types:\n");
+  for (unsigned i = 0; i < NumEntries; ++i) {
+    BCR_TRACE(5, (void*)Tab[i].get() << " - " << Tab[i].get() << "\n");
+  }
+}
+
+
+void AbstractBytecodeParser::ParseConstantValue(const unsigned char *&Buf,
+                                             const unsigned char *EndBuf,
+                                             unsigned TypeID) {
+
+  // We must check for a ConstantExpr before switching by type because
+  // a ConstantExpr can be of any type, and has no explicit value.
+  // 
+  // 0 if not expr; numArgs if is expr
+  unsigned isExprNumArgs = read_vbr_uint(Buf, EndBuf);
+  
+  if (isExprNumArgs) {
+    unsigned Opcode = read_vbr_uint(Buf, EndBuf);
+    const Type* Typ = getType(TypeID);
+    
+    // FIXME: Encoding of constant exprs could be much more compact!
+    std::vector<std::pair<const Type*,unsigned> > ArgVec;
+    ArgVec.reserve(isExprNumArgs);
+
+    // Read the slot number and types of each of the arguments
+    for (unsigned i = 0; i != isExprNumArgs; ++i) {
+      unsigned ArgValSlot = read_vbr_uint(Buf, EndBuf);
+      unsigned ArgTypeSlot = read_vbr_uint(Buf, EndBuf);
+      BCR_TRACE(4, "CE Arg " << i << ": Type: '" << *getType(ArgTypeSlot)
+                << "'  slot: " << ArgValSlot << "\n");
+      
+      // Get the arg value from its slot if it exists, otherwise a placeholder
+      ArgVec.push_back(std::make_pair(getType(ArgTypeSlot), ArgValSlot));
+    }
+
+    handler->handleConstantExpression( Opcode, Typ, ArgVec );
+    return;
+  }
+  
+  // Ok, not an ConstantExpr.  We now know how to read the given type...
+  const Type *Ty = getType(TypeID);
+  switch (Ty->getPrimitiveID()) {
+  case Type::BoolTyID: {
+    unsigned Val = read_vbr_uint(Buf, EndBuf);
+    if (Val != 0 && Val != 1) 
+      PARSE_ERROR("Invalid boolean value read.");
+
+    handler->handleConstantValue( ConstantBool::get(Val == 1));
+    break;
+  }
+
+  case Type::UByteTyID:   // Unsigned integer types...
+  case Type::UShortTyID:
+  case Type::UIntTyID: {
+    unsigned Val = read_vbr_uint(Buf, EndBuf);
+    if (!ConstantUInt::isValueValidForType(Ty, Val)) 
+      throw std::string("Invalid unsigned byte/short/int read.");
+    handler->handleConstantValue( ConstantUInt::get(Ty, Val) );
+    break;
+  }
+
+  case Type::ULongTyID: {
+    handler->handleConstantValue( ConstantUInt::get(Ty, read_vbr_uint64(Buf, EndBuf)) );
+    break;
+  }
+
+  case Type::SByteTyID:   // Signed integer types...
+  case Type::ShortTyID:
+  case Type::IntTyID: {
+  case Type::LongTyID:
+    int64_t Val = read_vbr_int64(Buf, EndBuf);
+    if (!ConstantSInt::isValueValidForType(Ty, Val)) 
+      throw std::string("Invalid signed byte/short/int/long read.");
+    handler->handleConstantValue(  ConstantSInt::get(Ty, Val) );
+    break;
+  }
+
+  case Type::FloatTyID: {
+    float F;
+    input_data(Buf, EndBuf, &F, &F+1);
+    handler->handleConstantValue( ConstantFP::get(Ty, F) );
+    break;
+  }
+
+  case Type::DoubleTyID: {
+    double Val;
+    input_data(Buf, EndBuf, &Val, &Val+1);
+    handler->handleConstantValue( ConstantFP::get(Ty, Val) );
+    break;
+  }
+
+  case Type::TypeTyID:
+    PARSE_ERROR("Type constants shouldn't live in constant table!");
+    break;
+
+  case Type::ArrayTyID: {
+    const ArrayType *AT = cast<ArrayType>(Ty);
+    unsigned NumElements = AT->getNumElements();
+    std::vector<unsigned> Elements;
+    Elements.reserve(NumElements);
+    while (NumElements--)     // Read all of the elements of the constant.
+      Elements.push_back(read_vbr_uint(Buf, EndBuf));
+
+    handler->handleConstantArray( AT, Elements );
+    break;
+  }
+
+  case Type::StructTyID: {
+    const StructType *ST = cast<StructType>(Ty);
+    std::vector<unsigned> Elements;
+    Elements.reserve(ST->getNumElements());
+    for (unsigned i = 0; i != ST->getNumElements(); ++i)
+      Elements.push_back(read_vbr_uint(Buf, EndBuf));
+
+    handler->handleConstantStruct( ST, Elements );
+  }    
+
+  case Type::PointerTyID: {  // ConstantPointerRef value...
+    const PointerType *PT = cast<PointerType>(Ty);
+    unsigned Slot = read_vbr_uint(Buf, EndBuf);
+    handler->handleConstantPointer( PT, Slot );
+  }
+
+  default:
+    PARSE_ERROR("Don't know how to deserialize constant value of type '"+
+                      Ty->getDescription());
+  }
+}
+
+void AbstractBytecodeParser::ParseGlobalTypes(const unsigned char *&Buf,
+                                      const unsigned char *EndBuf) {
+  ParseConstantPool(Buf, EndBuf, ModuleTypes);
+}
+
+void AbstractBytecodeParser::ParseStringConstants(const unsigned char *&Buf,
+                                          const unsigned char *EndBuf,
+                                          unsigned NumEntries ){
+  for (; NumEntries; --NumEntries) {
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    const Type *Ty = getType(Typ);
+    if (!isa<ArrayType>(Ty))
+      throw std::string("String constant data invalid!");
+    
+    const ArrayType *ATy = cast<ArrayType>(Ty);
+    if (ATy->getElementType() != Type::SByteTy &&
+        ATy->getElementType() != Type::UByteTy)
+      throw std::string("String constant data invalid!");
+    
+    // Read character data.  The type tells us how long the string is.
+    char Data[ATy->getNumElements()];
+    input_data(Buf, EndBuf, Data, Data+ATy->getNumElements());
+
+    std::vector<Constant*> Elements(ATy->getNumElements());
+    if (ATy->getElementType() == Type::SByteTy)
+      for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
+        Elements[i] = ConstantSInt::get(Type::SByteTy, (signed char)Data[i]);
+    else
+      for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
+        Elements[i] = ConstantUInt::get(Type::UByteTy, (unsigned char)Data[i]);
+
+    // Create the constant, inserting it as needed.
+    ConstantArray *C = cast<ConstantArray>( ConstantArray::get(ATy, Elements) );
+    handler->handleConstantString( C );
+  }
+}
+
+
+void AbstractBytecodeParser::ParseConstantPool(const unsigned char *&Buf,
+                                       const unsigned char *EndBuf,
+                                       TypeListTy &TypeTab) {
+  while (Buf < EndBuf) {
+    unsigned NumEntries = read_vbr_uint(Buf, EndBuf);
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    if (Typ == Type::TypeTyID) {
+      ParseTypeConstants(Buf, EndBuf, TypeTab, NumEntries);
+    } else if (Typ == Type::VoidTyID) {
+      ParseStringConstants(Buf, EndBuf, NumEntries);
+    } else {
+      BCR_TRACE(3, "Type: '" << *getType(Typ) << "'  NumEntries: "
+                << NumEntries << "\n");
+
+      for (unsigned i = 0; i < NumEntries; ++i) {
+        ParseConstantValue(Buf, EndBuf, Typ);
+      }
+    }
+  }
+  
+  if (Buf > EndBuf) PARSE_ERROR("Read past end of buffer.");
+}
+
+void AbstractBytecodeParser::ParseModuleGlobalInfo(BufPtr &Buf, BufPtr End) {
+
+  handler->handleModuleGlobalsBegin();
+
+  // Read global variables...
+  unsigned VarType = read_vbr_uint(Buf, End);
+  while (VarType != Type::VoidTyID) { // List is terminated by Void
+    // VarType Fields: bit0 = isConstant, bit1 = hasInitializer, bit2,3,4 =
+    // Linkage, bit4+ = slot#
+    unsigned SlotNo = VarType >> 5;
+    unsigned LinkageID = (VarType >> 2) & 7;
+    bool isConstant = VarType & 1;
+    bool hasInitializer = VarType & 2;
+    GlobalValue::LinkageTypes Linkage;
+
+    switch (LinkageID) {
+    case 0: Linkage = GlobalValue::ExternalLinkage;  break;
+    case 1: Linkage = GlobalValue::WeakLinkage;      break;
+    case 2: Linkage = GlobalValue::AppendingLinkage; break;
+    case 3: Linkage = GlobalValue::InternalLinkage;  break;
+    case 4: Linkage = GlobalValue::LinkOnceLinkage;  break;
+    default: 
+      PARSE_ERROR("Unknown linkage type: " << LinkageID);
+      Linkage = GlobalValue::InternalLinkage;
+      break;
+    }
+
+    const Type *Ty = getType(SlotNo);
+    if ( !Ty ) {
+      PARSE_ERROR("Global has no type! SlotNo=" << SlotNo);
+    }
+
+    if ( !isa<PointerType>(Ty)) {
+      PARSE_ERROR("Global not a pointer type! Ty= " << Ty->getDescription());
+    }
+
+    const Type *ElTy = cast<PointerType>(Ty)->getElementType();
+
+    // Create the global variable...
+    if (hasInitializer)
+      handler->handleGlobalVariable( ElTy, isConstant, Linkage );
+    else {
+      unsigned initSlot = read_vbr_uint(Buf,End);
+      handler->handleInitializedGV( ElTy, isConstant, Linkage, initSlot );
+    }
+
+    // Get next item
+    VarType = read_vbr_uint(Buf, End);
+  }
+
+  // Read the function objects for all of the functions that are coming
+  unsigned FnSignature = read_vbr_uint(Buf, End);
+  while (FnSignature != Type::VoidTyID) { // List is terminated by Void
+    const Type *Ty = getType(FnSignature);
+    if (!isa<PointerType>(Ty) ||
+        !isa<FunctionType>(cast<PointerType>(Ty)->getElementType())) {
+      PARSE_ERROR( "Function not a pointer to function type! Ty = " +
+                        Ty->getDescription());
+      // FIXME: what should Ty be if handler continues?
+    }
+
+    // We create functions by passing the underlying FunctionType to create...
+    Ty = cast<PointerType>(Ty)->getElementType();
+
+    // Save this for later so we know type of lazily instantiated functions
+    FunctionSignatureList.push_back(Ty);
+
+    handler->handleFunctionDeclaration(Ty);
+
+    // Get Next function signature
+    FnSignature = read_vbr_uint(Buf, End);
+  }
+
+  if (hasInconsistentModuleGlobalInfo)
+    align32(Buf, End);
+
+  // This is for future proofing... in the future extra fields may be added that
+  // we don't understand, so we transparently ignore them.
+  //
+  Buf = End;
+
+  handler->handleModuleGlobalsEnd();
+}
+
+void AbstractBytecodeParser::ParseVersionInfo(BufPtr &Buf, BufPtr EndBuf) {
+  unsigned Version = read_vbr_uint(Buf, EndBuf);
+
+  // Unpack version number: low four bits are for flags, top bits = version
+  Module::Endianness  Endianness;
+  Module::PointerSize PointerSize;
+  Endianness  = (Version & 1) ? Module::BigEndian : Module::LittleEndian;
+  PointerSize = (Version & 2) ? Module::Pointer64 : Module::Pointer32;
+
+  bool hasNoEndianness = Version & 4;
+  bool hasNoPointerSize = Version & 8;
+  
+  RevisionNum = Version >> 4;
+
+  // Default values for the current bytecode version
+  hasInconsistentModuleGlobalInfo = false;
+  hasExplicitPrimitiveZeros = false;
+  hasRestrictedGEPTypes = false;
+
+  switch (RevisionNum) {
+  case 0:               //  LLVM 1.0, 1.1 release version
+    // Base LLVM 1.0 bytecode format.
+    hasInconsistentModuleGlobalInfo = true;
+    hasExplicitPrimitiveZeros = true;
+    // FALL THROUGH
+  case 1:               // LLVM 1.2 release version
+    // LLVM 1.2 added explicit support for emitting strings efficiently.
+
+    // Also, it fixed the problem where the size of the ModuleGlobalInfo block
+    // included the size for the alignment at the end, where the rest of the
+    // blocks did not.
+
+    // LLVM 1.2 and before required that GEP indices be ubyte constants for
+    // structures and longs for sequential types.
+    hasRestrictedGEPTypes = true;
+
+    // FALL THROUGH
+  case 2:               // LLVM 1.3 release version
+    break;
+
+  default:
+    PARSE_ERROR("Unknown bytecode version number: " << RevisionNum);
+  }
+
+  if (hasNoEndianness) Endianness  = Module::AnyEndianness;
+  if (hasNoPointerSize) PointerSize = Module::AnyPointerSize;
+
+  handler->handleVersionInfo(RevisionNum, Endianness, PointerSize );
+}
+
+void AbstractBytecodeParser::ParseModule(BufPtr &Buf, BufPtr EndBuf ) {
+  unsigned Type, Size;
+  readBlock(Buf, EndBuf, Type, Size);
+  if (Type != BytecodeFormat::Module || Buf+Size != EndBuf)
+    // Hrm, not a class?
+    PARSE_ERROR("Expected Module block! B: " << unsigned(intptr_t(Buf)) <<
+        ", S: " << Size << " E: " << unsigned(intptr_t(EndBuf))); 
+
+  // Read into instance variables...
+  ParseVersionInfo(Buf, EndBuf);
+  align32(Buf, EndBuf);
+
+  bool SeenModuleGlobalInfo = false;
+  bool SeenGlobalTypePlane = false;
+  while (Buf < EndBuf) {
+    BufPtr OldBuf = Buf;
+    readBlock(Buf, EndBuf, Type, Size);
+
+    switch (Type) {
+
+    case BytecodeFormat::GlobalTypePlane:
+      if ( SeenGlobalTypePlane )
+	PARSE_ERROR("Two GlobalTypePlane Blocks Encountered!");
+
+      ParseGlobalTypes(Buf, Buf+Size);
+      SeenGlobalTypePlane = true;
+      break;
+
+    case BytecodeFormat::ModuleGlobalInfo: 
+      if ( SeenModuleGlobalInfo )
+	PARSE_ERROR("Two ModuleGlobalInfo Blocks Encountered!");
+      ParseModuleGlobalInfo(Buf, Buf+Size);
+      SeenModuleGlobalInfo = true;
+      break;
+
+    case BytecodeFormat::ConstantPool:
+      ParseConstantPool(Buf, Buf+Size, ModuleTypes);
+      break;
+
+    case BytecodeFormat::Function:
+      ParseFunctionLazily(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::SymbolTable:
+      ParseSymbolTable(Buf, Buf+Size );
+      break;
+
+    default:
+      Buf += Size;
+      if (OldBuf > Buf) 
+      {
+	PARSE_ERROR("Unexpected Block of Type" << Type << "encountered!" );
+      }
+      break;
+    }
+    align32(Buf, EndBuf);
+  }
+}
+
+void AbstractBytecodeParser::ParseBytecode(
+       BufPtr Buf, unsigned Length,
+       const std::string &ModuleID) {
+
+  handler->handleStart();
+  unsigned char *EndBuf = (unsigned char*)(Buf + Length);
+
+  // Read and check signature...
+  unsigned Sig = read(Buf, EndBuf);
+  if (Sig != ('l' | ('l' << 8) | ('v' << 16) | ('m' << 24))) {
+    PARSE_ERROR("Invalid bytecode signature: " << Sig);
+  }
+
+  handler->handleModuleBegin(ModuleID);
+
+  this->ParseModule(Buf, EndBuf);
+
+  handler->handleModuleEnd(ModuleID);
+
+  handler->handleFinish();
+}
+
+// vim: sw=2

lib/Bytecode/Analyzer/Parser.h

@@ -0,0 +1,178 @@
+//===-- Parser.h - Definitions internal to the reader -----------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the interface to the Bytecode Parser
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef BYTECODE_PARSER_H
+#define BYTECODE_PARSER_H
+
+#include "ReaderPrimitives.h"
+#include "BytecodeHandler.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include <utility>
+#include <vector>
+#include <map>
+
+namespace llvm {
+
+struct LazyFunctionInfo {
+  const unsigned char *Buf, *EndBuf;
+  LazyFunctionInfo(const unsigned char *B = 0, const unsigned char *EB = 0)
+    : Buf(B), EndBuf(EB) {}
+};
+
+typedef std::map<const Type*, LazyFunctionInfo> LazyFunctionMap;
+
+class AbstractBytecodeParser {
+  AbstractBytecodeParser(const AbstractBytecodeParser &);  // DO NOT IMPLEMENT
+  void operator=(const AbstractBytecodeParser &);  // DO NOT IMPLEMENT
+public:
+  AbstractBytecodeParser( BytecodeHandler* h ) { handler = h; }
+  ~AbstractBytecodeParser() { }
+
+  void ParseBytecode(const unsigned char *Buf, unsigned Length,
+                     const std::string &ModuleID);
+
+  void dump() const {
+    std::cerr << "AbstractBytecodeParser instance!\n";
+  }
+
+private:
+  // Information about the module, extracted from the bytecode revision number.
+  unsigned char RevisionNum;        // The rev # itself
+
+  // Flags to distinguish LLVM 1.0 & 1.1 bytecode formats (revision #0)
+
+  // Revision #0 had an explicit alignment of data only for the ModuleGlobalInfo
+  // block.  This was fixed to be like all other blocks in 1.2
+  bool hasInconsistentModuleGlobalInfo;
+
+  // Revision #0 also explicitly encoded zero values for primitive types like
+  // int/sbyte/etc.
+  bool hasExplicitPrimitiveZeros;
+
+  // Flags to control features specific the LLVM 1.2 and before (revision #1)
+
+  // LLVM 1.2 and earlier required that getelementptr structure indices were
+  // ubyte constants and that sequential type indices were longs.
+  bool hasRestrictedGEPTypes;
+
+
+  /// CompactionTable - If a compaction table is active in the current function,
+  /// this is the mapping that it contains.
+  std::vector<Type*> CompactionTypeTable;
+
+  // ConstantFwdRefs - This maintains a mapping between <Type, Slot #>'s and
+  // forward references to constants.  Such values may be referenced before they
+  // are defined, and if so, the temporary object that they represent is held
+  // here.
+  //
+  typedef std::map<std::pair<const Type*,unsigned>, Constant*> ConstantRefsType;
+  ConstantRefsType ConstantFwdRefs;
+
+  // TypesLoaded - This vector mirrors the Values[TypeTyID] plane.  It is used
+  // to deal with forward references to types.
+  //
+  typedef std::vector<PATypeHolder> TypeListTy;
+  TypeListTy ModuleTypes;
+  TypeListTy FunctionTypes;
+
+  // When the ModuleGlobalInfo section is read, we create a FunctionType object
+  // for each function in the module. When the function is loaded, this type is
+  // used to instantiate the actual function object.
+  std::vector<const Type*> FunctionSignatureList;
+
+  // Constant values are read in after global variables.  Because of this, we
+  // must defer setting the initializers on global variables until after module
+  // level constants have been read.  In the mean time, this list keeps track of
+  // what we must do.
+  //
+  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
+
+  // For lazy reading-in of functions, we need to save away several pieces of
+  // information about each function: its begin and end pointer in the buffer
+  // and its FunctionSlot.
+  // 
+  LazyFunctionMap LazyFunctionLoadMap;
+
+  /// The handler for parsing
+  BytecodeHandler* handler;
+  
+private:
+  const Type *AbstractBytecodeParser::getType(unsigned ID);
+  /// getGlobalTableType - This is just like getType, but when a compaction
+  /// table is in use, it is ignored.  Also, no forward references or other
+  /// fancy features are supported.
+  const Type *getGlobalTableType(unsigned Slot) {
+    if (Slot < Type::FirstDerivedTyID) {
+      const Type *Ty = Type::getPrimitiveType((Type::PrimitiveID)Slot);
+      assert(Ty && "Not a primitive type ID?");
+      return Ty;
+    }
+    Slot -= Type::FirstDerivedTyID;
+    if (Slot >= ModuleTypes.size())
+      throw std::string("Illegal compaction table type reference!");
+    return ModuleTypes[Slot];
+  }
+
+  unsigned getGlobalTableTypeSlot(const Type *Ty) {
+    if (Ty->isPrimitiveType())
+      return Ty->getPrimitiveID();
+    TypeListTy::iterator I = find(ModuleTypes.begin(),
+                                        ModuleTypes.end(), Ty);
+    if (I == ModuleTypes.end())
+      throw std::string("Didn't find type in ModuleTypes.");
+    return Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
+  }
+
+public:
+  typedef const unsigned char* BufPtr;
+  void ParseModule             (BufPtr &Buf, BufPtr End);
+  void ParseNextFunction       (Type* FType) ;
+  void ParseAllFunctionBodies  ();
+
+private:
+  void ParseVersionInfo        (BufPtr &Buf, BufPtr End);
+  void ParseModuleGlobalInfo   (BufPtr &Buf, BufPtr End);
+  void ParseSymbolTable        (BufPtr &Buf, BufPtr End);
+  void ParseFunctionLazily     (BufPtr &Buf, BufPtr End);
+  void ParseFunctionBody       (const Type* FType, BufPtr &Buf, BufPtr EndBuf);
+  void ParseCompactionTable    (BufPtr &Buf, BufPtr End);
+  void ParseGlobalTypes        (BufPtr &Buf, BufPtr End);
+
+  void ParseBasicBlock         (BufPtr &Buf, BufPtr End, unsigned BlockNo);
+  unsigned ParseInstructionList(BufPtr &Buf, BufPtr End);
+  
+  bool ParseInstruction        (BufPtr &Buf, BufPtr End, 
+	                        std::vector<unsigned>& Args);
+
+  void ParseConstantPool       (BufPtr &Buf, BufPtr End, TypeListTy& List);
+  void ParseConstantValue      (BufPtr &Buf, BufPtr End, unsigned TypeID);
+  void ParseTypeConstants      (BufPtr &Buf, BufPtr End, TypeListTy &Tab,
+					unsigned NumEntries);
+  const Type *ParseTypeConstant(BufPtr &Buf, BufPtr End);
+  void ParseStringConstants    (BufPtr &Buf, BufPtr End, unsigned NumEntries);
+
+};
+
+
+static inline void readBlock(const unsigned char *&Buf,
+                             const unsigned char *EndBuf, 
+                             unsigned &Type, unsigned &Size) {
+  Type = read(Buf, EndBuf);
+  Size = read(Buf, EndBuf);
+}
+
+} // End llvm namespace
+
+#endif
+// vim: sw=2

lib/Bytecode/Analyzer/ReaderPrimitives.h

@@ -0,0 +1,101 @@
+//===-- ReaderPrimitives.h - Bytecode file format reading prims -*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This header defines some basic functions for reading basic primitive types
+// from a bytecode stream.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef READERPRIMITIVES_H
+#define READERPRIMITIVES_H
+
+#include "Support/DataTypes.h"
+#include <string>
+
+namespace llvm {
+
+  static inline unsigned read(const unsigned char *&Buf,
+                              const unsigned char *EndBuf) {
+    if (Buf+4 > EndBuf) throw std::string("Ran out of data!");
+    Buf += 4;
+    return Buf[-4] | (Buf[-3] << 8) | (Buf[-2] << 16) | (Buf[-1] << 24);
+  }
+
+
+  // read_vbr - Read an unsigned integer encoded in variable bitrate format.
+  //
+  static inline unsigned read_vbr_uint(const unsigned char *&Buf, 
+                                       const unsigned char *EndBuf) {
+    unsigned Shift = 0;
+    unsigned Result = 0;
+    
+    do {
+      if (Buf == EndBuf) throw std::string("Ran out of data!");
+      Result |= (unsigned)((*Buf++) & 0x7F) << Shift;
+      Shift += 7;
+    } while (Buf[-1] & 0x80);
+    return Result;
+  }
+  
+  static inline uint64_t read_vbr_uint64(const unsigned char *&Buf, 
+                                         const unsigned char *EndBuf) {
+    unsigned Shift = 0;
+    uint64_t Result = 0;
+    
+    do {
+      if (Buf == EndBuf) throw std::string("Ran out of data!");
+      Result |= (uint64_t)((*Buf++) & 0x7F) << Shift;
+      Shift += 7;
+    } while (Buf[-1] & 0x80);
+    return Result;
+  }
+  
+  static inline int64_t read_vbr_int64(const unsigned char *&Buf, 
+                                       const unsigned char *EndBuf) {
+    uint64_t R = read_vbr_uint64(Buf, EndBuf);
+    if (R & 1) {
+      if (R != 1)
+        return -(int64_t)(R >> 1);
+      else   // There is no such thing as -0 with integers.  "-0" really means
+             // 0x8000000000000000.
+        return 1LL << 63;
+    } else
+      return  (int64_t)(R >> 1);
+  }
+  
+  // align32 - Round up to multiple of 32 bits...
+  static inline void align32(const unsigned char *&Buf, 
+                             const unsigned char *EndBuf) {
+    Buf = (const unsigned char *)((unsigned long)(Buf+3) & (~3UL));
+    if (Buf > EndBuf) throw std::string("Ran out of data!");
+  }
+  
+  static inline std::string read_str(const unsigned char *&Buf,
+                                     const unsigned char *EndBuf) {
+    unsigned Size = read_vbr_uint(Buf, EndBuf);
+    const unsigned char *OldBuf = Buf;
+    Buf += Size;
+    if (Buf > EndBuf)             // Size invalid?
+      throw std::string("Ran out of data reading a string!");
+    return std::string((char*)OldBuf, Size);
+  }
+  
+  static inline void input_data(const unsigned char *&Buf,
+                                const unsigned char *EndBuf, 
+                                void *Ptr, void *End) {
+    unsigned char *Start = (unsigned char *)Ptr;
+    unsigned Amount = (unsigned char *)End - Start;
+    if (Buf+Amount > EndBuf) throw std::string("Ran out of data!");
+    std::copy(Buf, Buf+Amount, Start);
+    Buf += Amount;
+  }
+  
+} // End llvm namespace
+
+#endif

lib/Bytecode/Makefile

@@ -7,7 +7,7 @@
 # 
 ##===----------------------------------------------------------------------===##
 LEVEL = ../..
-DIRS = Reader Writer
+DIRS = Analyzer Reader Writer
 
 include $(LEVEL)/Makefile.common
 

lib/Bytecode/Reader/Analyzer.cpp

@@ -0,0 +1,242 @@
+//===-- BytecodeHandler.cpp - Parsing Handler -------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeHandler class that gets called by the
+//  AbstractBytecodeParser when parsing events occur.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+
+using namespace llvm;
+
+
+namespace {
+
+class AnalyzerHandler : public BytecodeHandler {
+public:
+  bool handleError(const std::string& str )
+  {
+    return false;
+  }
+
+  void handleStart()
+  {
+  }
+
+  void handleFinish()
+  {
+  }
+
+  void handleModuleBegin(const std::string& id)
+  {
+  }
+
+  void handleModuleEnd(const std::string& id)
+  {
+  }
+
+  void handleVersionInfo(
+    unsigned char RevisionNum,        ///< Byte code revision number
+    Module::Endianness Endianness,    ///< Endianness indicator
+    Module::PointerSize PointerSize   ///< PointerSize indicator
+  )
+  {
+  }
+
+  void handleModuleGlobalsBegin()
+  {
+  }
+
+  void handleGlobalVariable( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes ///< The linkage type of the GV
+  )
+  {
+  }
+
+  void handleInitializedGV( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes,///< The linkage type of the GV
+    unsigned initSlot         ///< Slot number of GV's initializer
+  )
+  {
+  }
+
+  virtual void handleType( const Type* Ty ) 
+  {
+  }
+
+  void handleFunctionDeclaration( 
+    const Type* FuncType      ///< The type of the function
+  )
+  {
+  }
+
+  void handleModuleGlobalsEnd()
+  {
+  }
+
+  void handleCompactionTableBegin()
+  {
+  }
+
+  void handleCompactionTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries
+  )
+  {
+  }
+
+  void handleCompactionTableType( 
+    unsigned i, 
+    unsigned TypSlot, 
+    const Type* 
+  )
+  {
+  }
+
+  void handleCompactionTableValue( 
+    unsigned i, 
+    unsigned ValSlot, 
+    const Type* 
+  )
+  {
+  }
+
+  void handleCompactionTableEnd()
+  {
+  }
+
+  void handleSymbolTableBegin()
+  {
+  }
+
+  void handleSymbolTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries, 
+    const Type* Typ
+  )
+  {
+  }
+
+  void handleSymbolTableType( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+  }
+
+  void handleSymbolTableValue( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+  }
+
+  void handleSymbolTableEnd()
+  {
+  }
+
+  void handleFunctionBegin(
+    const Type* FType, 
+    GlobalValue::LinkageTypes linkage 
+  )
+  {
+  }
+
+  void handleFunctionEnd(
+    const Type* FType
+  )
+  {
+  }
+
+  void handleBasicBlockBegin(
+    unsigned blocknum
+  )
+  {
+  }
+
+  bool handleInstruction(
+    unsigned Opcode, 
+    const Type* iType, 
+    std::vector<unsigned>& Operands
+  )
+  {
+    return false;
+  }
+
+  void handleBasicBlockEnd(unsigned blocknum)
+  {
+  }
+
+  void handleGlobalConstantsBegin()
+  {
+  }
+
+  void handleConstantExpression( 
+      unsigned Opcode, 
+      const Type* Typ, 
+      std::vector<std::pair<const Type*,unsigned> > ArgVec 
+    )
+  {
+  }
+
+  void handleConstantValue( Constant * c )
+  {
+  }
+
+  void handleConstantArray( 
+	  const ArrayType* AT, 
+	  std::vector<unsigned>& Elements )
+  {
+  }
+
+  void handleConstantStruct(
+	const StructType* ST,
+	std::vector<unsigned>& ElementSlots)
+  {
+  }
+
+  void handleConstantPointer(
+	const PointerType* PT, unsigned Slot)
+  {
+  }
+
+  void handleConstantString( const ConstantArray* CA ) 
+  {
+  }
+
+
+  void handleGlobalConstantsEnd()
+  {
+  }
+
+};
+
+}
+
+void llvm::BytecodeAnalyzer::AnalyzeBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+)
+{
+  AnalyzerHandler TheHandler;
+  AbstractBytecodeParser TheParser(&TheHandler);
+  TheParser.ParseBytecode( Buf, Length, ModuleID );
+  TheParser.ParseAllFunctionBodies();
+}
+
+// vim: sw=2

lib/Bytecode/Reader/AnalyzerInternals.h

@@ -0,0 +1,65 @@
+//===-- ReaderInternals.h - Definitions internal to the reader --*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines various stuff that is used by the bytecode reader.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ANALYZER_INTERNALS_H
+#define ANALYZER_INTERNALS_H
+
+#include "Parser.h"
+#include "llvm/Bytecode/Analyzer.h"
+
+// Enable to trace to figure out what the heck is going on when parsing fails
+//#define TRACE_LEVEL 10
+//#define DEBUG_OUTPUT
+
+#if TRACE_LEVEL    // ByteCodeReading_TRACEr
+#define BCR_TRACE(n, X) \
+    if (n < TRACE_LEVEL) std::cerr << std::string(n*2, ' ') << X
+#else
+#define BCR_TRACE(n, X)
+#endif
+
+namespace llvm {
+
+class BytecodeAnalyzer {
+  BytecodeAnalyzer(const BytecodeAnalyzer &);  // DO NOT IMPLEMENT
+  void operator=(const BytecodeAnalyzer &);  // DO NOT IMPLEMENT
+public:
+  BytecodeAnalyzer() { }
+  ~BytecodeAnalyzer() { }
+
+  void AnalyzeBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  );
+
+  void DumpBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  );
+
+  void dump() const {
+    std::cerr << "BytecodeParser instance!\n";
+  }
+private:
+  BytecodeAnalysis TheAnalysis;
+};
+
+} // End llvm namespace
+
+#endif
+
+// vim: sw=2

lib/Bytecode/Reader/AnalyzerWrappers.cpp

@@ -0,0 +1,208 @@
+//===- AnalyzerWrappers.cpp - Analyze bytecode from file or buffer  -------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file implements loading and analysis of a bytecode file and analyzing a
+// bytecode buffer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bytecode/Analyzer.h"
+#include "AnalyzerInternals.h"
+#include "Support/FileUtilities.h"
+#include "Support/StringExtras.h"
+#include "Config/unistd.h"
+#include <cerrno>
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// BytecodeFileAnalyzer - Analyze from an mmap'able file descriptor.
+//
+
+namespace {
+  /// BytecodeFileAnalyzer - parses a bytecode file from a file
+  class BytecodeFileAnalyzer : public BytecodeAnalyzer {
+  private:
+    unsigned char *Buffer;
+    unsigned Length;
+
+    BytecodeFileAnalyzer(const BytecodeFileAnalyzer&); // Do not implement
+    void operator=(const BytecodeFileAnalyzer &BFR); // Do not implement
+
+  public:
+    BytecodeFileAnalyzer(const std::string &Filename, BytecodeAnalysis& bca);
+    ~BytecodeFileAnalyzer();
+  };
+}
+
+static std::string ErrnoMessage (int savedErrNum, std::string descr) {
+   return ::strerror(savedErrNum) + std::string(", while trying to ") + descr;
+}
+
+BytecodeFileAnalyzer::BytecodeFileAnalyzer(const std::string &Filename, 
+	                                   BytecodeAnalysis& bca) {
+  Buffer = (unsigned char*)ReadFileIntoAddressSpace(Filename, Length);
+  if (Buffer == 0)
+    throw "Error reading file '" + Filename + "'.";
+
+  try {
+    // Parse the bytecode we mmapped in
+    if ( bca.dumpBytecode ) 
+      DumpBytecode(Buffer, Length, bca, Filename);
+    AnalyzeBytecode(Buffer, Length, bca, Filename);
+  } catch (...) {
+    UnmapFileFromAddressSpace(Buffer, Length);
+    throw;
+  }
+}
+
+BytecodeFileAnalyzer::~BytecodeFileAnalyzer() {
+  // Unmmap the bytecode...
+  UnmapFileFromAddressSpace(Buffer, Length);
+}
+
+//===----------------------------------------------------------------------===//
+// BytecodeBufferAnalyzer - Read from a memory buffer
+//
+
+namespace {
+  /// BytecodeBufferAnalyzer - parses a bytecode file from a buffer
+  ///
+  class BytecodeBufferAnalyzer : public BytecodeAnalyzer {
+  private:
+    const unsigned char *Buffer;
+    bool MustDelete;
+
+    BytecodeBufferAnalyzer(const BytecodeBufferAnalyzer&); // Do not implement
+    void operator=(const BytecodeBufferAnalyzer &BFR);   // Do not implement
+
+  public:
+    BytecodeBufferAnalyzer(const unsigned char *Buf, unsigned Length,
+	                   BytecodeAnalysis& bca, const std::string &ModuleID);
+    ~BytecodeBufferAnalyzer();
+
+  };
+}
+
+BytecodeBufferAnalyzer::BytecodeBufferAnalyzer(const unsigned char *Buf,
+					       unsigned Length,
+					       BytecodeAnalysis& bca,
+					       const std::string &ModuleID) {
+  // If not aligned, allocate a new buffer to hold the bytecode...
+  const unsigned char *ParseBegin = 0;
+  if ((intptr_t)Buf & 3) {
+    Buffer = new unsigned char[Length+4];
+    unsigned Offset = 4 - ((intptr_t)Buffer & 3);   // Make sure it's aligned
+    ParseBegin = Buffer + Offset;
+    memcpy((unsigned char*)ParseBegin, Buf, Length);    // Copy it over
+    MustDelete = true;
+  } else {
+    // If we don't need to copy it over, just use the caller's copy
+    ParseBegin = Buffer = Buf;
+    MustDelete = false;
+  }
+  try {
+    if ( bca.dumpBytecode ) 
+      DumpBytecode(ParseBegin, Length, bca, ModuleID);
+    AnalyzeBytecode(ParseBegin, Length, bca, ModuleID);
+  } catch (...) {
+    if (MustDelete) delete [] Buffer;
+    throw;
+  }
+}
+
+BytecodeBufferAnalyzer::~BytecodeBufferAnalyzer() {
+  if (MustDelete) delete [] Buffer;
+}
+
+//===----------------------------------------------------------------------===//
+//  BytecodeStdinAnalyzer - Read bytecode from Standard Input
+//
+
+namespace {
+  /// BytecodeStdinAnalyzer - parses a bytecode file from stdin
+  /// 
+  class BytecodeStdinAnalyzer : public BytecodeAnalyzer {
+  private:
+    std::vector<unsigned char> FileData;
+    unsigned char *FileBuf;
+
+    BytecodeStdinAnalyzer(const BytecodeStdinAnalyzer&); // Do not implement
+    void operator=(const BytecodeStdinAnalyzer &BFR);  // Do not implement
+
+  public:
+    BytecodeStdinAnalyzer(BytecodeAnalysis& bca);
+  };
+}
+
+BytecodeStdinAnalyzer::BytecodeStdinAnalyzer(BytecodeAnalysis& bca ) {
+  int BlockSize;
+  unsigned char Buffer[4096*4];
+
+  // Read in all of the data from stdin, we cannot mmap stdin...
+  while ((BlockSize = ::read(0 /*stdin*/, Buffer, 4096*4))) {
+    if (BlockSize == -1)
+      throw ErrnoMessage(errno, "read from standard input");
+    
+    FileData.insert(FileData.end(), Buffer, Buffer+BlockSize);
+  }
+
+  if (FileData.empty())
+    throw std::string("Standard Input empty!");
+
+  FileBuf = &FileData[0];
+  if (bca.dumpBytecode)
+    DumpBytecode(&FileData[0], FileData.size(), bca, "<stdin>");
+  AnalyzeBytecode(FileBuf, FileData.size(), bca, "<stdin>");
+}
+
+//===----------------------------------------------------------------------===//
+// Wrapper functions
+//===----------------------------------------------------------------------===//
+
+// AnalyzeBytecodeFile - analyze one file
+void llvm::AnalyzeBytecodeFile(const std::string &Filename, 
+                               BytecodeAnalysis& bca,
+                               std::string *ErrorStr) 
+{
+  try {
+    if ( Filename != "-" )
+      BytecodeFileAnalyzer bfa(Filename,bca);
+    else
+      BytecodeStdinAnalyzer bsa(bca);
+  } catch (std::string &err) {
+    if (ErrorStr) *ErrorStr = err;
+  }
+}
+
+// AnalyzeBytecodeBuffer - analyze a buffer
+void llvm::AnalyzeBytecodeBuffer(
+       const unsigned char* Buffer, ///< Pointer to start of bytecode buffer
+       unsigned BufferSize,         ///< Size of the bytecode buffer
+       BytecodeAnalysis& Results,   ///< The results of the analysis
+       std::string* ErrorStr        ///< Errors, if any.
+     ) 
+{
+  try {
+    BytecodeBufferAnalyzer(Buffer, BufferSize, Results, "<buffer>" );
+  } catch (std::string& err ) {
+    if ( ErrorStr) *ErrorStr = err;
+  }
+}
+
+
+/// This function prints the contents of rhe BytecodeAnalysis structure in
+/// a human legible form.
+/// @brief Print BytecodeAnalysis structure to an ostream
+void llvm::PrintBytecodeAnalysis(BytecodeAnalysis& bca, std::ostream& Out )
+{
+  Out << "Not Implemented Yet.\n";
+}
+
+// vim: sw=2

lib/Bytecode/Reader/Dumper.cpp

@@ -0,0 +1,311 @@
+//===-- BytecodeDumper.cpp - Parsing Handler --------------------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the BytecodeDumper class that gets called by the
+//  AbstractBytecodeParser when parsing events occur. It merely dumps the
+//  information presented to it from the parser.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+#include "llvm/Constant.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instruction.h"
+#include "llvm/Type.h"
+
+using namespace llvm;
+
+namespace {
+
+class BytecodeDumper : public llvm::BytecodeHandler {
+public:
+
+  virtual bool handleError(const std::string& str )
+  {
+    std::cout << "ERROR: " << str << "\n";
+    return true;
+  }
+
+  virtual void handleStart()
+  {
+    std::cout << "Bytecode {\n";
+  }
+
+  virtual void handleFinish()
+  {
+    std::cout << "} End Bytecode\n";
+  }
+
+  virtual void handleModuleBegin(const std::string& id)
+  {
+    std::cout << "  Module " << id << " {\n";
+  }
+
+  virtual void handleModuleEnd(const std::string& id)
+  {
+    std::cout << "  } End Module " << id << "\n";
+  }
+
+  virtual void handleVersionInfo(
+    unsigned char RevisionNum,        ///< Byte code revision number
+    Module::Endianness Endianness,    ///< Endianness indicator
+    Module::PointerSize PointerSize   ///< PointerSize indicator
+  )
+  {
+    std::cout << "    RevisionNum: " << int(RevisionNum) 
+	      << " Endianness: " << Endianness
+	      << " PointerSize: " << PointerSize << "\n";
+  }
+
+  virtual void handleModuleGlobalsBegin()
+  {
+    std::cout << "    BLOCK: ModuleGlobalInfo {\n";
+  }
+
+  virtual void handleGlobalVariable( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes Linkage ///< The linkage type of the GV
+  )
+  {
+    std::cout << "      GV: Uninitialized, " 
+	     << ( isConstant? "Constant, " : "Variable, ")
+	     << " Linkage=" << Linkage << " Type=" 
+	     << ElemType->getDescription() << "\n"; 
+  }
+
+  virtual void handleInitializedGV( 
+    const Type* ElemType,     ///< The type of the global variable
+    bool isConstant,          ///< Whether the GV is constant or not
+    GlobalValue::LinkageTypes Linkage,///< The linkage type of the GV
+    unsigned initSlot         ///< Slot number of GV's initializer
+  )
+  {
+    std::cout << "      GV: Initialized, " 
+	     << ( isConstant? "Constant, " : "Variable, ")
+	     << " Linkage=" << Linkage << " Type=" 
+	     << ElemType->getDescription()
+	     << " InitializerSlot=" << initSlot << "\n"; 
+  }
+
+  virtual void handleType( const Type* Ty ) 
+  {
+    std::cout << "      Type: " << Ty->getDescription() << "\n";
+  }
+
+  virtual void handleFunctionDeclaration( const Type* FuncType )
+  {
+    std::cout << "      Function: " << FuncType->getDescription() << "\n";
+  }
+
+  virtual void handleModuleGlobalsEnd()
+  {
+    std::cout << "    } END BLOCK: ModuleGlobalInfo\n";
+  }
+
+  void handleCompactionTableBegin()
+  {
+    std::cout << "    BLOCK: CompactionTable {\n";
+  }
+
+  virtual void handleCompactionTablePlane( unsigned Ty, unsigned NumEntries )
+  {
+    std::cout << "      Plane: Ty=" << Ty << " Size=" << NumEntries << "\n";
+  }
+
+  virtual void handleCompactionTableType( 
+    unsigned i, 
+    unsigned TypSlot, 
+    const Type* Ty
+  )
+  {
+    std::cout << "        Type: " << i << " Slot:" << TypSlot 
+	      << " is " << Ty->getDescription() << "\n"; 
+  }
+
+  virtual void handleCompactionTableValue( 
+    unsigned i, 
+    unsigned ValSlot, 
+    const Type* Ty 
+  )
+  {
+    std::cout << "        Value: " << i << " Slot:" << ValSlot 
+	      << " is " << Ty->getDescription() << "\n"; 
+  }
+
+  virtual void handleCompactionTableEnd()
+  {
+    std::cout << "    } END BLOCK: CompactionTable\n";
+  }
+
+  virtual void handleSymbolTableBegin()
+  {
+    std::cout << "    BLOCK: SymbolTable {\n";
+  }
+
+  virtual void handleSymbolTablePlane( 
+    unsigned Ty, 
+    unsigned NumEntries, 
+    const Type* Typ
+  )
+  {
+    std::cout << "      Plane: Ty=" << Ty << " Size=" << NumEntries
+	      << " Type: " << Typ->getDescription() << "\n"; 
+  }
+
+  virtual void handleSymbolTableType( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+    std::cout << "        Type " << i << " Slot=" << slot
+	      << " Name: " << name << "\n"; 
+  }
+
+  virtual void handleSymbolTableValue( 
+    unsigned i, 
+    unsigned slot, 
+    const std::string& name 
+  )
+  {
+    std::cout << "        Value " << i << " Slot=" << slot
+	      << " Name: " << name << "\n";
+  }
+
+  virtual void handleSymbolTableEnd()
+  {
+    std::cout << "    } END BLOCK: SymbolTable\n";
+  }
+
+  virtual void handleFunctionBegin(
+    const Type* FType, 
+    GlobalValue::LinkageTypes linkage 
+  )
+  {
+    std::cout << "    BLOCK: Function {\n";
+    std::cout << "      Linkage: " << linkage << "\n";
+    std::cout << "      Type: " << FType->getDescription() << "\n";
+  }
+
+  virtual void handleFunctionEnd(
+    const Type* FType
+  )
+  {
+    std::cout << "    } END BLOCK: Function\n";
+  }
+
+  virtual void handleBasicBlockBegin(
+    unsigned blocknum
+  )
+  {
+    std::cout << "      BLOCK: BasicBlock #" << blocknum << "{\n";
+  }
+
+  virtual bool handleInstruction(
+    unsigned Opcode, 
+    const Type* iType, 
+    std::vector<unsigned>& Operands
+  )
+  {
+    std::cout << "        INST: OpCode=" 
+	      << Instruction::getOpcodeName(Opcode) << " Type=" 
+	      << iType->getDescription() << "\n";
+    for ( unsigned i = 0; i < Operands.size(); ++i ) 
+      std::cout << "          Op#" << i << " Slot=" << Operands[i] << "\n";
+    
+    return Instruction::isTerminator(Opcode); 
+  }
+
+  virtual void handleBasicBlockEnd(unsigned blocknum)
+  {
+    std::cout << "      } END BLOCK: BasicBlock #" << blocknum << "{\n";
+  }
+
+  virtual void handleGlobalConstantsBegin()
+  {
+    std::cout << "    BLOCK: GlobalConstants {\n";
+  }
+
+  virtual void handleConstantExpression( 
+      unsigned Opcode, 
+      const Type* Typ, 
+      std::vector<std::pair<const Type*,unsigned> > ArgVec 
+    )
+  {
+    std::cout << "      EXPR: " << Instruction::getOpcodeName(Opcode)
+	      << " Type=" << Typ->getDescription() << "\n";
+    for ( unsigned i = 0; i < ArgVec.size(); ++i ) 
+      std::cout << "        Arg#" << i << " Type=" 
+	<< ArgVec[i].first->getDescription() << " Slot=" 
+	<< ArgVec[i].second << "\n";
+  }
+
+  virtual void handleConstantValue( Constant * c )
+  {
+    std::cout << "      VALUE: ";
+    c->print(std::cout);
+    std::cout << "\n";
+  }
+
+  virtual void handleConstantArray( 
+	  const ArrayType* AT, 
+	  std::vector<unsigned>& Elements )
+  {
+    std::cout << "      ARRAY: " << AT->getDescription() << "\n";
+    for ( unsigned i = 0; i < Elements.size(); ++i ) 
+      std::cout << "        #" << i << " Slot=" << Elements[i] << "\n";
+  }
+
+  virtual void handleConstantStruct(
+	const StructType* ST,
+	std::vector<unsigned>& Elements)
+  {
+    std::cout << "      STRUC: " << ST->getDescription() << "\n";
+    for ( unsigned i = 0; i < Elements.size(); ++i ) 
+      std::cout << "        #" << i << " Slot=" << Elements[i] << "\n";
+  }
+
+  virtual void handleConstantPointer(
+	const PointerType* PT, unsigned Slot)
+  {
+    std::cout << "      POINT: " << PT->getDescription() 
+	      << " Slot=" << Slot << "\n";
+  }
+
+  virtual void handleConstantString( const ConstantArray* CA ) 
+  {
+    std::cout << "      STRNG: ";
+    CA->print(std::cout); 
+    std::cout << "\n";
+  }
+
+  virtual void handleGlobalConstantsEnd()
+  {
+    std::cout << "    } END BLOCK: GlobalConstants\n";
+  }
+};
+
+}
+
+void BytecodeAnalyzer::DumpBytecode(
+    const unsigned char *Buf, 
+    unsigned Length,
+    BytecodeAnalysis& bca,
+    const std::string &ModuleID
+  )
+{
+  BytecodeDumper TheHandler;
+  AbstractBytecodeParser TheParser(&TheHandler);
+  TheParser.ParseBytecode( Buf, Length, ModuleID );
+  TheParser.ParseAllFunctionBodies();
+}
+
+// vim: sw=2

lib/Bytecode/Reader/Parser.cpp

@@ -0,0 +1,877 @@
+//===- Reader.cpp - Code to read bytecode files ---------------------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This library implements the functionality defined in llvm/Bytecode/Reader.h
+//
+// Note that this library should be as fast as possible, reentrant, and 
+// threadsafe!!
+//
+// TODO: Allow passing in an option to ignore the symbol table
+//
+//===----------------------------------------------------------------------===//
+
+#include "AnalyzerInternals.h"
+#include "llvm/Module.h"
+#include "llvm/Bytecode/Format.h"
+#include "Support/StringExtras.h"
+#include <iostream>
+#include <sstream>
+
+using namespace llvm;
+
+#define PARSE_ERROR(inserters) \
+  { \
+    std::ostringstream errormsg; \
+    errormsg << inserters; \
+    if ( ! handler->handleError( errormsg.str() ) ) \
+      throw std::string(errormsg.str()); \
+  }
+
+const Type *AbstractBytecodeParser::getType(unsigned ID) {
+  //cerr << "Looking up Type ID: " << ID << "\n";
+
+  if (ID < Type::FirstDerivedTyID)
+    if (const Type *T = Type::getPrimitiveType((Type::PrimitiveID)ID))
+      return T;   // Asked for a primitive type...
+
+  // Otherwise, derived types need offset...
+  ID -= Type::FirstDerivedTyID;
+
+  if (!CompactionTypeTable.empty()) {
+    if (ID >= CompactionTypeTable.size())
+      PARSE_ERROR("Type ID out of range for compaction table!");
+    return CompactionTypeTable[ID];
+  }
+
+  // Is it a module-level type?
+  if (ID < ModuleTypes.size())
+    return ModuleTypes[ID].get();
+
+  // Nope, is it a function-level type?
+  ID -= ModuleTypes.size();
+  if (ID < FunctionTypes.size())
+    return FunctionTypes[ID].get();
+
+  PARSE_ERROR("Illegal type reference!");
+  return Type::VoidTy;
+}
+
+bool AbstractBytecodeParser::ParseInstruction(BufPtr& Buf, BufPtr EndBuf,
+                                      std::vector<unsigned> &Operands) {
+  Operands.clear();
+  unsigned iType = 0;
+  unsigned Opcode = 0;
+  unsigned Op = read(Buf, EndBuf);
+
+  // bits   Instruction format:        Common to all formats
+  // --------------------------
+  // 01-00: Opcode type, fixed to 1.
+  // 07-02: Opcode
+  Opcode    = (Op >> 2) & 63;
+  Operands.resize((Op >> 0) & 03);
+
+  switch (Operands.size()) {
+  case 1:
+    // bits   Instruction format:
+    // --------------------------
+    // 19-08: Resulting type plane
+    // 31-20: Operand #1 (if set to (2^12-1), then zero operands)
+    //
+    iType   = (Op >>  8) & 4095;
+    Operands[0] = (Op >> 20) & 4095;
+    if (Operands[0] == 4095)    // Handle special encoding for 0 operands...
+      Operands.resize(0);
+    break;
+  case 2:
+    // bits   Instruction format:
+    // --------------------------
+    // 15-08: Resulting type plane
+    // 23-16: Operand #1
+    // 31-24: Operand #2  
+    //
+    iType   = (Op >>  8) & 255;
+    Operands[0] = (Op >> 16) & 255;
+    Operands[1] = (Op >> 24) & 255;
+    break;
+  case 3:
+    // bits   Instruction format:
+    // --------------------------
+    // 13-08: Resulting type plane
+    // 19-14: Operand #1
+    // 25-20: Operand #2
+    // 31-26: Operand #3
+    //
+    iType   = (Op >>  8) & 63;
+    Operands[0] = (Op >> 14) & 63;
+    Operands[1] = (Op >> 20) & 63;
+    Operands[2] = (Op >> 26) & 63;
+    break;
+  case 0:
+    Buf -= 4;  // Hrm, try this again...
+    Opcode = read_vbr_uint(Buf, EndBuf);
+    Opcode >>= 2;
+    iType = read_vbr_uint(Buf, EndBuf);
+
+    unsigned NumOperands = read_vbr_uint(Buf, EndBuf);
+    Operands.resize(NumOperands);
+
+    if (NumOperands == 0)
+      PARSE_ERROR("Zero-argument instruction found; this is invalid.");
+
+    for (unsigned i = 0; i != NumOperands; ++i)
+      Operands[i] = read_vbr_uint(Buf, EndBuf);
+    align32(Buf, EndBuf);
+    break;
+  }
+
+  return handler->handleInstruction(Opcode, getType(iType), Operands);
+}
+
+/// ParseBasicBlock - In LLVM 1.0 bytecode files, we used to output one
+/// basicblock at a time.  This method reads in one of the basicblock packets.
+void AbstractBytecodeParser::ParseBasicBlock(BufPtr &Buf,
+                                            BufPtr EndBuf,
+                                            unsigned BlockNo) {
+  handler->handleBasicBlockBegin( BlockNo );
+
+  std::vector<unsigned> Args;
+  bool is_terminating = false;
+  while (Buf < EndBuf)
+    is_terminating = ParseInstruction(Buf, EndBuf, Args);
+
+  if ( ! is_terminating )
+    PARSE_ERROR(
+      "Failed to recognize instruction as terminating at end of block");
+
+  handler->handleBasicBlockEnd( BlockNo );
+}
+
+
+/// ParseInstructionList - Parse all of the BasicBlock's & Instruction's in the
+/// body of a function.  In post 1.0 bytecode files, we no longer emit basic
+/// block individually, in order to avoid per-basic-block overhead.
+unsigned AbstractBytecodeParser::ParseInstructionList( BufPtr &Buf, BufPtr EndBuf) {
+  unsigned BlockNo = 0;
+  std::vector<unsigned> Args;
+
+  while (Buf < EndBuf) {
+    handler->handleBasicBlockBegin( BlockNo );
+
+    // Read instructions into this basic block until we get to a terminator
+    bool is_terminating = false;
+    while (Buf < EndBuf && !is_terminating )
+	is_terminating = ParseInstruction(Buf, EndBuf, Args ) ;
+
+    if (!is_terminating)
+      PARSE_ERROR( "Non-terminated basic block found!");
+
+    handler->handleBasicBlockEnd( BlockNo );
+    ++BlockNo;
+  }
+  return BlockNo;
+}
+
+void AbstractBytecodeParser::ParseSymbolTable(BufPtr &Buf, BufPtr EndBuf) {
+  handler->handleSymbolTableBegin();
+
+  while (Buf < EndBuf) {
+    // Symtab block header: [num entries][type id number]
+    unsigned NumEntries = read_vbr_uint(Buf, EndBuf);
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    const Type *Ty = getType(Typ);
+
+    handler->handleSymbolTablePlane( Typ, NumEntries, Ty );
+
+    for (unsigned i = 0; i != NumEntries; ++i) {
+      // Symtab entry: [def slot #][name]
+      unsigned slot = read_vbr_uint(Buf, EndBuf);
+      std::string Name = read_str(Buf, EndBuf);
+
+      if (Typ == Type::TypeTyID)
+        handler->handleSymbolTableType( i, slot, Name );
+      else
+	handler->handleSymbolTableValue( i, slot, Name );
+    }
+  }
+
+  if (Buf > EndBuf) 
+    PARSE_ERROR("Tried to read past end of buffer while reading symbol table.");
+
+  handler->handleSymbolTableEnd();
+}
+
+void AbstractBytecodeParser::ParseFunctionLazily(BufPtr &Buf, BufPtr EndBuf) {
+  if (FunctionSignatureList.empty())
+    throw std::string("FunctionSignatureList empty!");
+
+  const Type *FType = FunctionSignatureList.back();
+  FunctionSignatureList.pop_back();
+
+  // Save the information for future reading of the function
+  LazyFunctionLoadMap[FType] = LazyFunctionInfo(Buf, EndBuf);
+  // Pretend we've `parsed' this function
+  Buf = EndBuf;
+}
+
+void AbstractBytecodeParser::ParseNextFunction(Type* FType) {
+  // Find {start, end} pointers and slot in the map. If not there, we're done.
+  LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.find(FType);
+
+  // Make sure we found it
+  if ( Fi == LazyFunctionLoadMap.end() ) {
+    PARSE_ERROR("Unrecognized function of type " << FType->getDescription());
+    return;
+  }
+
+  BufPtr Buf = Fi->second.Buf;
+  BufPtr EndBuf = Fi->second.EndBuf;
+  assert(Fi->first == FType);
+
+  LazyFunctionLoadMap.erase(Fi);
+
+  this->ParseFunctionBody( FType, Buf, EndBuf );
+}
+
+void AbstractBytecodeParser::ParseFunctionBody(const Type* FType, 
+                                               BufPtr &Buf, BufPtr EndBuf ) {
+
+  GlobalValue::LinkageTypes Linkage = GlobalValue::ExternalLinkage;
+
+  unsigned LinkageType = read_vbr_uint(Buf, EndBuf);
+  switch (LinkageType) {
+  case 0: Linkage = GlobalValue::ExternalLinkage; break;
+  case 1: Linkage = GlobalValue::WeakLinkage; break;
+  case 2: Linkage = GlobalValue::AppendingLinkage; break;
+  case 3: Linkage = GlobalValue::InternalLinkage; break;
+  case 4: Linkage = GlobalValue::LinkOnceLinkage; break;
+  default:
+    PARSE_ERROR("Invalid linkage type for Function.");
+    Linkage = GlobalValue::InternalLinkage;
+    break;
+  }
+
+  handler->handleFunctionBegin(FType,Linkage);
+
+  // Keep track of how many basic blocks we have read in...
+  unsigned BlockNum = 0;
+  bool InsertedArguments = false;
+
+  while (Buf < EndBuf) {
+    unsigned Type, Size;
+    BufPtr OldBuf = Buf;
+    readBlock(Buf, EndBuf, Type, Size);
+
+    switch (Type) {
+    case BytecodeFormat::ConstantPool:
+      ParseConstantPool(Buf, Buf+Size, FunctionTypes );
+      break;
+
+    case BytecodeFormat::CompactionTable:
+      ParseCompactionTable(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::BasicBlock:
+      ParseBasicBlock(Buf, Buf+Size, BlockNum++);
+      break;
+
+    case BytecodeFormat::InstructionList:
+      if (BlockNum) 
+	PARSE_ERROR("InstructionList must come before basic blocks!");
+      BlockNum = ParseInstructionList(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::SymbolTable:
+      ParseSymbolTable(Buf, Buf+Size );
+      break;
+
+    default:
+      Buf += Size;
+      if (OldBuf > Buf)
+	PARSE_ERROR("Wrapped around reading bytecode");
+      break;
+    }
+
+    // Malformed bc file if read past end of block.
+    align32(Buf, EndBuf);
+  }
+
+  handler->handleFunctionEnd(FType);
+
+  // Clear out function-level types...
+  FunctionTypes.clear();
+  CompactionTypeTable.clear();
+}
+
+void AbstractBytecodeParser::ParseAllFunctionBodies() {
+  LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.begin();
+  LazyFunctionMap::iterator Fe = LazyFunctionLoadMap.end();
+
+  while ( Fi != Fe ) {
+    const Type* FType = Fi->first;
+    this->ParseFunctionBody(FType, Fi->second.Buf, Fi->second.EndBuf);
+  }
+}
+
+void AbstractBytecodeParser::ParseCompactionTable(BufPtr &Buf, BufPtr End) {
+
+  handler->handleCompactionTableBegin();
+
+  while (Buf != End) {
+    unsigned NumEntries = read_vbr_uint(Buf, End);
+    unsigned Ty;
+
+    if ((NumEntries & 3) == 3) {
+      NumEntries >>= 2;
+      Ty = read_vbr_uint(Buf, End);
+    } else {
+      Ty = NumEntries >> 2;
+      NumEntries &= 3;
+    }
+
+    handler->handleCompactionTablePlane( Ty, NumEntries );
+
+    if (Ty == Type::TypeTyID) {
+      for (unsigned i = 0; i != NumEntries; ++i) {
+	unsigned TypeSlot = read_vbr_uint(Buf,End);
+        const Type *Typ = getGlobalTableType(TypeSlot);
+	handler->handleCompactionTableType( i, TypeSlot, Typ );
+      }
+    } else {
+      const Type *Typ = getType(Ty);
+      // Push the implicit zero
+      for (unsigned i = 0; i != NumEntries; ++i) {
+	unsigned ValSlot = read_vbr_uint(Buf, End);
+	handler->handleCompactionTableValue( i, ValSlot, Typ );
+      }
+    }
+  }
+  handler->handleCompactionTableEnd();
+}
+
+const Type *AbstractBytecodeParser::ParseTypeConstant(const unsigned char *&Buf,
+					      const unsigned char *EndBuf) {
+  unsigned PrimType = read_vbr_uint(Buf, EndBuf);
+
+  const Type *Val = 0;
+  if ((Val = Type::getPrimitiveType((Type::PrimitiveID)PrimType)))
+    return Val;
+  
+  switch (PrimType) {
+  case Type::FunctionTyID: {
+    const Type *RetType = getType(read_vbr_uint(Buf, EndBuf));
+
+    unsigned NumParams = read_vbr_uint(Buf, EndBuf);
+
+    std::vector<const Type*> Params;
+    while (NumParams--)
+      Params.push_back(getType(read_vbr_uint(Buf, EndBuf)));
+
+    bool isVarArg = Params.size() && Params.back() == Type::VoidTy;
+    if (isVarArg) Params.pop_back();
+
+    Type* result = FunctionType::get(RetType, Params, isVarArg);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::ArrayTyID: {
+    unsigned ElTyp = read_vbr_uint(Buf, EndBuf);
+    const Type *ElementType = getType(ElTyp);
+
+    unsigned NumElements = read_vbr_uint(Buf, EndBuf);
+
+    BCR_TRACE(5, "Array Type Constant #" << ElTyp << " size=" 
+              << NumElements << "\n");
+    Type* result =  ArrayType::get(ElementType, NumElements);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::StructTyID: {
+    std::vector<const Type*> Elements;
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    while (Typ) {         // List is terminated by void/0 typeid
+      Elements.push_back(getType(Typ));
+      Typ = read_vbr_uint(Buf, EndBuf);
+    }
+
+    Type* result = StructType::get(Elements);
+    handler->handleType( result );
+    return result;
+  }
+  case Type::PointerTyID: {
+    unsigned ElTyp = read_vbr_uint(Buf, EndBuf);
+    BCR_TRACE(5, "Pointer Type Constant #" << ElTyp << "\n");
+    Type* result = PointerType::get(getType(ElTyp));
+    handler->handleType( result );
+    return result;
+  }
+
+  case Type::OpaqueTyID: {
+    Type* result = OpaqueType::get();
+    handler->handleType( result );
+    return result;
+  }
+
+  default:
+    PARSE_ERROR("Don't know how to deserialize primitive type" << PrimType << "\n");
+    return Val;
+  }
+}
+
+// ParseTypeConstants - We have to use this weird code to handle recursive
+// types.  We know that recursive types will only reference the current slab of
+// values in the type plane, but they can forward reference types before they
+// have been read.  For example, Type #0 might be '{ Ty#1 }' and Type #1 might
+// be 'Ty#0*'.  When reading Type #0, type number one doesn't exist.  To fix
+// this ugly problem, we pessimistically insert an opaque type for each type we
+// are about to read.  This means that forward references will resolve to
+// something and when we reread the type later, we can replace the opaque type
+// with a new resolved concrete type.
+//
+void AbstractBytecodeParser::ParseTypeConstants(const unsigned char *&Buf,
+                                        const unsigned char *EndBuf,
+					TypeListTy &Tab,
+					unsigned NumEntries) {
+  assert(Tab.size() == 0 && "should not have read type constants in before!");
+
+  // Insert a bunch of opaque types to be resolved later...
+  Tab.reserve(NumEntries);
+  for (unsigned i = 0; i != NumEntries; ++i)
+    Tab.push_back(OpaqueType::get());
+
+  // Loop through reading all of the types.  Forward types will make use of the
+  // opaque types just inserted.
+  //
+  for (unsigned i = 0; i != NumEntries; ++i) {
+    const Type *NewTy = ParseTypeConstant(Buf, EndBuf), *OldTy = Tab[i].get();
+    if (NewTy == 0) throw std::string("Couldn't parse type!");
+    BCR_TRACE(4, "#" << i << ": Read Type Constant: '" << NewTy <<
+              "' Replacing: " << OldTy << "\n");
+
+    // Don't insertValue the new type... instead we want to replace the opaque
+    // type with the new concrete value...
+    //
+
+    // Refine the abstract type to the new type.  This causes all uses of the
+    // abstract type to use NewTy.  This also will cause the opaque type to be
+    // deleted...
+    //
+    cast<DerivedType>(const_cast<Type*>(OldTy))->refineAbstractTypeTo(NewTy);
+
+    // This should have replace the old opaque type with the new type in the
+    // value table... or with a preexisting type that was already in the system
+    assert(Tab[i] != OldTy && "refineAbstractType didn't work!");
+  }
+
+  BCR_TRACE(5, "Resulting types:\n");
+  for (unsigned i = 0; i < NumEntries; ++i) {
+    BCR_TRACE(5, (void*)Tab[i].get() << " - " << Tab[i].get() << "\n");
+  }
+}
+
+
+void AbstractBytecodeParser::ParseConstantValue(const unsigned char *&Buf,
+                                             const unsigned char *EndBuf,
+                                             unsigned TypeID) {
+
+  // We must check for a ConstantExpr before switching by type because
+  // a ConstantExpr can be of any type, and has no explicit value.
+  // 
+  // 0 if not expr; numArgs if is expr
+  unsigned isExprNumArgs = read_vbr_uint(Buf, EndBuf);
+  
+  if (isExprNumArgs) {
+    unsigned Opcode = read_vbr_uint(Buf, EndBuf);
+    const Type* Typ = getType(TypeID);
+    
+    // FIXME: Encoding of constant exprs could be much more compact!
+    std::vector<std::pair<const Type*,unsigned> > ArgVec;
+    ArgVec.reserve(isExprNumArgs);
+
+    // Read the slot number and types of each of the arguments
+    for (unsigned i = 0; i != isExprNumArgs; ++i) {
+      unsigned ArgValSlot = read_vbr_uint(Buf, EndBuf);
+      unsigned ArgTypeSlot = read_vbr_uint(Buf, EndBuf);
+      BCR_TRACE(4, "CE Arg " << i << ": Type: '" << *getType(ArgTypeSlot)
+                << "'  slot: " << ArgValSlot << "\n");
+      
+      // Get the arg value from its slot if it exists, otherwise a placeholder
+      ArgVec.push_back(std::make_pair(getType(ArgTypeSlot), ArgValSlot));
+    }
+
+    handler->handleConstantExpression( Opcode, Typ, ArgVec );
+    return;
+  }
+  
+  // Ok, not an ConstantExpr.  We now know how to read the given type...
+  const Type *Ty = getType(TypeID);
+  switch (Ty->getPrimitiveID()) {
+  case Type::BoolTyID: {
+    unsigned Val = read_vbr_uint(Buf, EndBuf);
+    if (Val != 0 && Val != 1) 
+      PARSE_ERROR("Invalid boolean value read.");
+
+    handler->handleConstantValue( ConstantBool::get(Val == 1));
+    break;
+  }
+
+  case Type::UByteTyID:   // Unsigned integer types...
+  case Type::UShortTyID:
+  case Type::UIntTyID: {
+    unsigned Val = read_vbr_uint(Buf, EndBuf);
+    if (!ConstantUInt::isValueValidForType(Ty, Val)) 
+      throw std::string("Invalid unsigned byte/short/int read.");
+    handler->handleConstantValue( ConstantUInt::get(Ty, Val) );
+    break;
+  }
+
+  case Type::ULongTyID: {
+    handler->handleConstantValue( ConstantUInt::get(Ty, read_vbr_uint64(Buf, EndBuf)) );
+    break;
+  }
+
+  case Type::SByteTyID:   // Signed integer types...
+  case Type::ShortTyID:
+  case Type::IntTyID: {
+  case Type::LongTyID:
+    int64_t Val = read_vbr_int64(Buf, EndBuf);
+    if (!ConstantSInt::isValueValidForType(Ty, Val)) 
+      throw std::string("Invalid signed byte/short/int/long read.");
+    handler->handleConstantValue(  ConstantSInt::get(Ty, Val) );
+    break;
+  }
+
+  case Type::FloatTyID: {
+    float F;
+    input_data(Buf, EndBuf, &F, &F+1);
+    handler->handleConstantValue( ConstantFP::get(Ty, F) );
+    break;
+  }
+
+  case Type::DoubleTyID: {
+    double Val;
+    input_data(Buf, EndBuf, &Val, &Val+1);
+    handler->handleConstantValue( ConstantFP::get(Ty, Val) );
+    break;
+  }
+
+  case Type::TypeTyID:
+    PARSE_ERROR("Type constants shouldn't live in constant table!");
+    break;
+
+  case Type::ArrayTyID: {
+    const ArrayType *AT = cast<ArrayType>(Ty);
+    unsigned NumElements = AT->getNumElements();
+    std::vector<unsigned> Elements;
+    Elements.reserve(NumElements);
+    while (NumElements--)     // Read all of the elements of the constant.
+      Elements.push_back(read_vbr_uint(Buf, EndBuf));
+
+    handler->handleConstantArray( AT, Elements );
+    break;
+  }
+
+  case Type::StructTyID: {
+    const StructType *ST = cast<StructType>(Ty);
+    std::vector<unsigned> Elements;
+    Elements.reserve(ST->getNumElements());
+    for (unsigned i = 0; i != ST->getNumElements(); ++i)
+      Elements.push_back(read_vbr_uint(Buf, EndBuf));
+
+    handler->handleConstantStruct( ST, Elements );
+  }    
+
+  case Type::PointerTyID: {  // ConstantPointerRef value...
+    const PointerType *PT = cast<PointerType>(Ty);
+    unsigned Slot = read_vbr_uint(Buf, EndBuf);
+    handler->handleConstantPointer( PT, Slot );
+  }
+
+  default:
+    PARSE_ERROR("Don't know how to deserialize constant value of type '"+
+                      Ty->getDescription());
+  }
+}
+
+void AbstractBytecodeParser::ParseGlobalTypes(const unsigned char *&Buf,
+                                      const unsigned char *EndBuf) {
+  ParseConstantPool(Buf, EndBuf, ModuleTypes);
+}
+
+void AbstractBytecodeParser::ParseStringConstants(const unsigned char *&Buf,
+                                          const unsigned char *EndBuf,
+                                          unsigned NumEntries ){
+  for (; NumEntries; --NumEntries) {
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    const Type *Ty = getType(Typ);
+    if (!isa<ArrayType>(Ty))
+      throw std::string("String constant data invalid!");
+    
+    const ArrayType *ATy = cast<ArrayType>(Ty);
+    if (ATy->getElementType() != Type::SByteTy &&
+        ATy->getElementType() != Type::UByteTy)
+      throw std::string("String constant data invalid!");
+    
+    // Read character data.  The type tells us how long the string is.
+    char Data[ATy->getNumElements()];
+    input_data(Buf, EndBuf, Data, Data+ATy->getNumElements());
+
+    std::vector<Constant*> Elements(ATy->getNumElements());
+    if (ATy->getElementType() == Type::SByteTy)
+      for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
+        Elements[i] = ConstantSInt::get(Type::SByteTy, (signed char)Data[i]);
+    else
+      for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
+        Elements[i] = ConstantUInt::get(Type::UByteTy, (unsigned char)Data[i]);
+
+    // Create the constant, inserting it as needed.
+    ConstantArray *C = cast<ConstantArray>( ConstantArray::get(ATy, Elements) );
+    handler->handleConstantString( C );
+  }
+}
+
+
+void AbstractBytecodeParser::ParseConstantPool(const unsigned char *&Buf,
+                                       const unsigned char *EndBuf,
+                                       TypeListTy &TypeTab) {
+  while (Buf < EndBuf) {
+    unsigned NumEntries = read_vbr_uint(Buf, EndBuf);
+    unsigned Typ = read_vbr_uint(Buf, EndBuf);
+    if (Typ == Type::TypeTyID) {
+      ParseTypeConstants(Buf, EndBuf, TypeTab, NumEntries);
+    } else if (Typ == Type::VoidTyID) {
+      ParseStringConstants(Buf, EndBuf, NumEntries);
+    } else {
+      BCR_TRACE(3, "Type: '" << *getType(Typ) << "'  NumEntries: "
+                << NumEntries << "\n");
+
+      for (unsigned i = 0; i < NumEntries; ++i) {
+        ParseConstantValue(Buf, EndBuf, Typ);
+      }
+    }
+  }
+  
+  if (Buf > EndBuf) PARSE_ERROR("Read past end of buffer.");
+}
+
+void AbstractBytecodeParser::ParseModuleGlobalInfo(BufPtr &Buf, BufPtr End) {
+
+  handler->handleModuleGlobalsBegin();
+
+  // Read global variables...
+  unsigned VarType = read_vbr_uint(Buf, End);
+  while (VarType != Type::VoidTyID) { // List is terminated by Void
+    // VarType Fields: bit0 = isConstant, bit1 = hasInitializer, bit2,3,4 =
+    // Linkage, bit4+ = slot#
+    unsigned SlotNo = VarType >> 5;
+    unsigned LinkageID = (VarType >> 2) & 7;
+    bool isConstant = VarType & 1;
+    bool hasInitializer = VarType & 2;
+    GlobalValue::LinkageTypes Linkage;
+
+    switch (LinkageID) {
+    case 0: Linkage = GlobalValue::ExternalLinkage;  break;
+    case 1: Linkage = GlobalValue::WeakLinkage;      break;
+    case 2: Linkage = GlobalValue::AppendingLinkage; break;
+    case 3: Linkage = GlobalValue::InternalLinkage;  break;
+    case 4: Linkage = GlobalValue::LinkOnceLinkage;  break;
+    default: 
+      PARSE_ERROR("Unknown linkage type: " << LinkageID);
+      Linkage = GlobalValue::InternalLinkage;
+      break;
+    }
+
+    const Type *Ty = getType(SlotNo);
+    if ( !Ty ) {
+      PARSE_ERROR("Global has no type! SlotNo=" << SlotNo);
+    }
+
+    if ( !isa<PointerType>(Ty)) {
+      PARSE_ERROR("Global not a pointer type! Ty= " << Ty->getDescription());
+    }
+
+    const Type *ElTy = cast<PointerType>(Ty)->getElementType();
+
+    // Create the global variable...
+    if (hasInitializer)
+      handler->handleGlobalVariable( ElTy, isConstant, Linkage );
+    else {
+      unsigned initSlot = read_vbr_uint(Buf,End);
+      handler->handleInitializedGV( ElTy, isConstant, Linkage, initSlot );
+    }
+
+    // Get next item
+    VarType = read_vbr_uint(Buf, End);
+  }
+
+  // Read the function objects for all of the functions that are coming
+  unsigned FnSignature = read_vbr_uint(Buf, End);
+  while (FnSignature != Type::VoidTyID) { // List is terminated by Void
+    const Type *Ty = getType(FnSignature);
+    if (!isa<PointerType>(Ty) ||
+        !isa<FunctionType>(cast<PointerType>(Ty)->getElementType())) {
+      PARSE_ERROR( "Function not a pointer to function type! Ty = " +
+                        Ty->getDescription());
+      // FIXME: what should Ty be if handler continues?
+    }
+
+    // We create functions by passing the underlying FunctionType to create...
+    Ty = cast<PointerType>(Ty)->getElementType();
+
+    // Save this for later so we know type of lazily instantiated functions
+    FunctionSignatureList.push_back(Ty);
+
+    handler->handleFunctionDeclaration(Ty);
+
+    // Get Next function signature
+    FnSignature = read_vbr_uint(Buf, End);
+  }
+
+  if (hasInconsistentModuleGlobalInfo)
+    align32(Buf, End);
+
+  // This is for future proofing... in the future extra fields may be added that
+  // we don't understand, so we transparently ignore them.
+  //
+  Buf = End;
+
+  handler->handleModuleGlobalsEnd();
+}
+
+void AbstractBytecodeParser::ParseVersionInfo(BufPtr &Buf, BufPtr EndBuf) {
+  unsigned Version = read_vbr_uint(Buf, EndBuf);
+
+  // Unpack version number: low four bits are for flags, top bits = version
+  Module::Endianness  Endianness;
+  Module::PointerSize PointerSize;
+  Endianness  = (Version & 1) ? Module::BigEndian : Module::LittleEndian;
+  PointerSize = (Version & 2) ? Module::Pointer64 : Module::Pointer32;
+
+  bool hasNoEndianness = Version & 4;
+  bool hasNoPointerSize = Version & 8;
+  
+  RevisionNum = Version >> 4;
+
+  // Default values for the current bytecode version
+  hasInconsistentModuleGlobalInfo = false;
+  hasExplicitPrimitiveZeros = false;
+  hasRestrictedGEPTypes = false;
+
+  switch (RevisionNum) {
+  case 0:               //  LLVM 1.0, 1.1 release version
+    // Base LLVM 1.0 bytecode format.
+    hasInconsistentModuleGlobalInfo = true;
+    hasExplicitPrimitiveZeros = true;
+    // FALL THROUGH
+  case 1:               // LLVM 1.2 release version
+    // LLVM 1.2 added explicit support for emitting strings efficiently.
+
+    // Also, it fixed the problem where the size of the ModuleGlobalInfo block
+    // included the size for the alignment at the end, where the rest of the
+    // blocks did not.
+
+    // LLVM 1.2 and before required that GEP indices be ubyte constants for
+    // structures and longs for sequential types.
+    hasRestrictedGEPTypes = true;
+
+    // FALL THROUGH
+  case 2:               // LLVM 1.3 release version
+    break;
+
+  default:
+    PARSE_ERROR("Unknown bytecode version number: " << RevisionNum);
+  }
+
+  if (hasNoEndianness) Endianness  = Module::AnyEndianness;
+  if (hasNoPointerSize) PointerSize = Module::AnyPointerSize;
+
+  handler->handleVersionInfo(RevisionNum, Endianness, PointerSize );
+}
+
+void AbstractBytecodeParser::ParseModule(BufPtr &Buf, BufPtr EndBuf ) {
+  unsigned Type, Size;
+  readBlock(Buf, EndBuf, Type, Size);
+  if (Type != BytecodeFormat::Module || Buf+Size != EndBuf)
+    // Hrm, not a class?
+    PARSE_ERROR("Expected Module block! B: " << unsigned(intptr_t(Buf)) <<
+        ", S: " << Size << " E: " << unsigned(intptr_t(EndBuf))); 
+
+  // Read into instance variables...
+  ParseVersionInfo(Buf, EndBuf);
+  align32(Buf, EndBuf);
+
+  bool SeenModuleGlobalInfo = false;
+  bool SeenGlobalTypePlane = false;
+  while (Buf < EndBuf) {
+    BufPtr OldBuf = Buf;
+    readBlock(Buf, EndBuf, Type, Size);
+
+    switch (Type) {
+
+    case BytecodeFormat::GlobalTypePlane:
+      if ( SeenGlobalTypePlane )
+	PARSE_ERROR("Two GlobalTypePlane Blocks Encountered!");
+
+      ParseGlobalTypes(Buf, Buf+Size);
+      SeenGlobalTypePlane = true;
+      break;
+
+    case BytecodeFormat::ModuleGlobalInfo: 
+      if ( SeenModuleGlobalInfo )
+	PARSE_ERROR("Two ModuleGlobalInfo Blocks Encountered!");
+      ParseModuleGlobalInfo(Buf, Buf+Size);
+      SeenModuleGlobalInfo = true;
+      break;
+
+    case BytecodeFormat::ConstantPool:
+      ParseConstantPool(Buf, Buf+Size, ModuleTypes);
+      break;
+
+    case BytecodeFormat::Function:
+      ParseFunctionLazily(Buf, Buf+Size);
+      break;
+
+    case BytecodeFormat::SymbolTable:
+      ParseSymbolTable(Buf, Buf+Size );
+      break;
+
+    default:
+      Buf += Size;
+      if (OldBuf > Buf) 
+      {
+	PARSE_ERROR("Unexpected Block of Type" << Type << "encountered!" );
+      }
+      break;
+    }
+    align32(Buf, EndBuf);
+  }
+}
+
+void AbstractBytecodeParser::ParseBytecode(
+       BufPtr Buf, unsigned Length,
+       const std::string &ModuleID) {
+
+  handler->handleStart();
+  unsigned char *EndBuf = (unsigned char*)(Buf + Length);
+
+  // Read and check signature...
+  unsigned Sig = read(Buf, EndBuf);
+  if (Sig != ('l' | ('l' << 8) | ('v' << 16) | ('m' << 24))) {
+    PARSE_ERROR("Invalid bytecode signature: " << Sig);
+  }
+
+  handler->handleModuleBegin(ModuleID);
+
+  this->ParseModule(Buf, EndBuf);
+
+  handler->handleModuleEnd(ModuleID);
+
+  handler->handleFinish();
+}
+
+// vim: sw=2

lib/Bytecode/Reader/Parser.h

@@ -0,0 +1,178 @@
+//===-- Parser.h - Definitions internal to the reader -----------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under the 
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+//  This header file defines the interface to the Bytecode Parser
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef BYTECODE_PARSER_H
+#define BYTECODE_PARSER_H
+
+#include "ReaderPrimitives.h"
+#include "BytecodeHandler.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include <utility>
+#include <vector>
+#include <map>
+
+namespace llvm {
+
+struct LazyFunctionInfo {
+  const unsigned char *Buf, *EndBuf;
+  LazyFunctionInfo(const unsigned char *B = 0, const unsigned char *EB = 0)
+    : Buf(B), EndBuf(EB) {}
+};
+
+typedef std::map<const Type*, LazyFunctionInfo> LazyFunctionMap;
+
+class AbstractBytecodeParser {
+  AbstractBytecodeParser(const AbstractBytecodeParser &);  // DO NOT IMPLEMENT
+  void operator=(const AbstractBytecodeParser &);  // DO NOT IMPLEMENT
+public:
+  AbstractBytecodeParser( BytecodeHandler* h ) { handler = h; }
+  ~AbstractBytecodeParser() { }
+
+  void ParseBytecode(const unsigned char *Buf, unsigned Length,
+                     const std::string &ModuleID);
+
+  void dump() const {
+    std::cerr << "AbstractBytecodeParser instance!\n";
+  }
+
+private:
+  // Information about the module, extracted from the bytecode revision number.
+  unsigned char RevisionNum;        // The rev # itself
+
+  // Flags to distinguish LLVM 1.0 & 1.1 bytecode formats (revision #0)
+
+  // Revision #0 had an explicit alignment of data only for the ModuleGlobalInfo
+  // block.  This was fixed to be like all other blocks in 1.2
+  bool hasInconsistentModuleGlobalInfo;
+
+  // Revision #0 also explicitly encoded zero values for primitive types like
+  // int/sbyte/etc.
+  bool hasExplicitPrimitiveZeros;
+
+  // Flags to control features specific the LLVM 1.2 and before (revision #1)
+
+  // LLVM 1.2 and earlier required that getelementptr structure indices were
+  // ubyte constants and that sequential type indices were longs.
+  bool hasRestrictedGEPTypes;
+
+
+  /// CompactionTable - If a compaction table is active in the current function,
+  /// this is the mapping that it contains.
+  std::vector<Type*> CompactionTypeTable;
+
+  // ConstantFwdRefs - This maintains a mapping between <Type, Slot #>'s and
+  // forward references to constants.  Such values may be referenced before they
+  // are defined, and if so, the temporary object that they represent is held
+  // here.
+  //
+  typedef std::map<std::pair<const Type*,unsigned>, Constant*> ConstantRefsType;
+  ConstantRefsType ConstantFwdRefs;
+
+  // TypesLoaded - This vector mirrors the Values[TypeTyID] plane.  It is used
+  // to deal with forward references to types.
+  //
+  typedef std::vector<PATypeHolder> TypeListTy;
+  TypeListTy ModuleTypes;
+  TypeListTy FunctionTypes;
+
+  // When the ModuleGlobalInfo section is read, we create a FunctionType object
+  // for each function in the module. When the function is loaded, this type is
+  // used to instantiate the actual function object.
+  std::vector<const Type*> FunctionSignatureList;
+
+  // Constant values are read in after global variables.  Because of this, we
+  // must defer setting the initializers on global variables until after module
+  // level constants have been read.  In the mean time, this list keeps track of
+  // what we must do.
+  //
+  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
+
+  // For lazy reading-in of functions, we need to save away several pieces of
+  // information about each function: its begin and end pointer in the buffer
+  // and its FunctionSlot.
+  // 
+  LazyFunctionMap LazyFunctionLoadMap;
+
+  /// The handler for parsing
+  BytecodeHandler* handler;
+  
+private:
+  const Type *AbstractBytecodeParser::getType(unsigned ID);
+  /// getGlobalTableType - This is just like getType, but when a compaction
+  /// table is in use, it is ignored.  Also, no forward references or other
+  /// fancy features are supported.
+  const Type *getGlobalTableType(unsigned Slot) {
+    if (Slot < Type::FirstDerivedTyID) {
+      const Type *Ty = Type::getPrimitiveType((Type::PrimitiveID)Slot);
+      assert(Ty && "Not a primitive type ID?");
+      return Ty;
+    }
+    Slot -= Type::FirstDerivedTyID;
+    if (Slot >= ModuleTypes.size())
+      throw std::string("Illegal compaction table type reference!");
+    return ModuleTypes[Slot];
+  }
+
+  unsigned getGlobalTableTypeSlot(const Type *Ty) {
+    if (Ty->isPrimitiveType())
+      return Ty->getPrimitiveID();
+    TypeListTy::iterator I = find(ModuleTypes.begin(),
+                                        ModuleTypes.end(), Ty);
+    if (I == ModuleTypes.end())
+      throw std::string("Didn't find type in ModuleTypes.");
+    return Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
+  }
+
+public:
+  typedef const unsigned char* BufPtr;
+  void ParseModule             (BufPtr &Buf, BufPtr End);
+  void ParseNextFunction       (Type* FType) ;
+  void ParseAllFunctionBodies  ();
+
+private:
+  void ParseVersionInfo        (BufPtr &Buf, BufPtr End);
+  void ParseModuleGlobalInfo   (BufPtr &Buf, BufPtr End);
+  void ParseSymbolTable        (BufPtr &Buf, BufPtr End);
+  void ParseFunctionLazily     (BufPtr &Buf, BufPtr End);
+  void ParseFunctionBody       (const Type* FType, BufPtr &Buf, BufPtr EndBuf);
+  void ParseCompactionTable    (BufPtr &Buf, BufPtr End);
+  void ParseGlobalTypes        (BufPtr &Buf, BufPtr End);
+
+  void ParseBasicBlock         (BufPtr &Buf, BufPtr End, unsigned BlockNo);
+  unsigned ParseInstructionList(BufPtr &Buf, BufPtr End);
+  
+  bool ParseInstruction        (BufPtr &Buf, BufPtr End, 
+	                        std::vector<unsigned>& Args);
+
+  void ParseConstantPool       (BufPtr &Buf, BufPtr End, TypeListTy& List);
+  void ParseConstantValue      (BufPtr &Buf, BufPtr End, unsigned TypeID);
+  void ParseTypeConstants      (BufPtr &Buf, BufPtr End, TypeListTy &Tab,
+					unsigned NumEntries);
+  const Type *ParseTypeConstant(BufPtr &Buf, BufPtr End);
+  void ParseStringConstants    (BufPtr &Buf, BufPtr End, unsigned NumEntries);
+
+};
+
+
+static inline void readBlock(const unsigned char *&Buf,
+                             const unsigned char *EndBuf, 
+                             unsigned &Type, unsigned &Size) {
+  Type = read(Buf, EndBuf);
+  Size = read(Buf, EndBuf);
+}
+
+} // End llvm namespace
+
+#endif
+// vim: sw=2

tools/Makefile

@@ -9,7 +9,8 @@
 
 LEVEL := ..
 PARALLEL_DIRS := llvm-as llvm-dis opt gccas llc llvm-link lli gccld llvm-stub \
-                 analyze extract bugpoint llvm-nm llvm-prof llvm-db llvm-ar
+                 analyze extract bugpoint llvm-nm llvm-prof llvm-db llvm-ar \
+		 llvm-abcd
 
 include $(LEVEL)/Makefile.common
 

tools/llvm-abcd/Makefile

@@ -0,0 +1,13 @@
+##===- tools/llvm-abcd/Makefile ----------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file was developed by Reid Spencer and is distributed under the 
+# University of Illinois Open Source License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+
+TOOLNAME = llvm-abcd
+USEDLIBS = bcanalyzer vmcore support.a
+include $(LEVEL)/Makefile.common

tools/llvm-abcd/llvm-abcd.cpp

@@ -0,0 +1,115 @@
+//===-- llvm-dis.cpp - The low-level LLVM disassembler --------------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This utility may be invoked in the following manner:
+//  llvm-dis [options]      - Read LLVM bytecode from stdin, write asm to stdout
+//  llvm-dis [options] x.bc - Read LLVM bytecode from the x.bc file, write asm
+//                            to the x.ll file.
+//  Options:
+//      --help   - Output information about command line switches
+//       -c      - Print C code instead of LLVM assembly
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bytecode/Analyzer.h"
+#include "Support/CommandLine.h"
+#include "llvm/System/Signals.h"
+#include <fstream>
+#include <iostream>
+
+using namespace llvm;
+
+static cl::opt<std::string>
+  InputFilename(cl::Positional, cl::desc("<input bytecode>"), cl::init("-"));
+
+static cl::opt<std::string> 
+  OutputFilename("o", cl::desc("Override output filename"), 
+    cl::value_desc("filename"));
+
+static cl::opt<bool> Force      ("f", cl::desc("Overwrite output files"));
+static cl::opt<bool> Detailed   ("d", cl::desc("Detailed output"));
+
+int 
+main(int argc, char **argv) 
+{
+  cl::ParseCommandLineOptions(argc, argv, 
+    " llvm-abcd Analysis of ByteCode Dumper\n");
+
+  PrintStackTraceOnErrorSignal();
+
+  std::ostream* Out = &std::cout;  // Default to printing to stdout...
+  std::istream* In  = &std::cin;   // Default to reading stdin
+  std::string ErrorMessage;
+  BytecodeAnalysis bca;
+
+  /// Analyze the bytecode file
+  AnalyzeBytecodeFile(InputFilename, bca, &ErrorMessage);
+
+  // If there was an error, print it and stop.
+  if ( ErrorMessage.size() ) {
+    std::cerr << argv[0] << ": " << ErrorMessage << "\n";
+    return 1;
+  }
+  
+  // Figure out where the output is going
+  if (OutputFilename != "") {   // Specified an output filename?
+    if (OutputFilename != "-") { // Not stdout?
+      if (!Force && std::ifstream(OutputFilename.c_str())) {
+        // If force is not specified, make sure not to overwrite a file!
+        std::cerr << argv[0] << ": error opening '" << OutputFilename
+                  << "': file exists! Sending to standard output.\n";
+      } else {
+        Out = new std::ofstream(OutputFilename.c_str());
+      }
+    }
+  } else {
+    if (InputFilename == "-") {
+      OutputFilename = "-";
+    } else {
+      std::string IFN = InputFilename;
+      int Len = IFN.length();
+      if (IFN[Len-3] == '.' && IFN[Len-2] == 'b' && IFN[Len-1] == 'c') {
+	// Source ends in .bc
+	OutputFilename = std::string(IFN.begin(), IFN.end()-3)+".abc";
+      } else {
+	OutputFilename = IFN+".abc";
+      }
+
+      if (!Force && std::ifstream(OutputFilename.c_str())) {
+        // If force is not specified, make sure not to overwrite a file!
+        std::cerr << argv[0] << ": error opening '" << OutputFilename
+                  << "': file exists! Sending to standard output.\n";
+      } else {
+        Out = new std::ofstream(OutputFilename.c_str());
+
+        // Make sure that the Out file gets unlinked from the disk if we get a
+        // SIGINT
+        RemoveFileOnSignal(OutputFilename);
+      }
+    }
+  }
+
+  if (!Out->good()) {
+    std::cerr << argv[0] << ": error opening " << OutputFilename
+              << ": sending to stdout instead!\n";
+    Out = &std::cout;
+  }
+
+  // All that abcd does is write the gathered statistics to the output
+  bca.dumpBytecode = true;
+  PrintBytecodeAnalysis(bca,*Out);
+
+  if (Out != &std::cout) {
+    ((std::ofstream*)Out)->close();
+    delete Out;
+  }
+  return 0;
+}
+
+// vim: sw=2