Copy llvm-bcanalyzer to build pnacl-bcanalyzer.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3405
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/15013003

7 files changed, 684 insertions, 3 deletions

diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 7e32507e91..e149a14831 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -43,6 +43,7 @@ add_subdirectory(llvm-mcmarkup)
 
 add_subdirectory(llvm-symbolizer)
 add_subdirectory(pnacl-abicheck)
+add_subdirectory(pnacl-bcanalyzer)
 add_subdirectory(pnacl-freeze)
 add_subdirectory(pnacl-thaw)
 add_subdirectory(bc-wrap)
diff --git a/tools/LLVMBuild.txt b/tools/LLVMBuild.txt
index b87ed92a30..c301ea9371 100644
--- a/tools/LLVMBuild.txt
+++ b/tools/LLVMBuild.txt
@@ -16,7 +16,7 @@
 ;===------------------------------------------------------------------------===;
 
 [common]
-subdirectories = bugpoint llc lli llvm-ar llvm-as llvm-bcanalyzer llvm-cov llvm-diff llvm-dis llvm-dwarfdump llvm-extract llvm-jitlistener llvm-link llvm-mc llvm-nm llvm-objdump llvm-prof llvm-ranlib llvm-rtdyld llvm-size macho-dump opt llvm-mcmarkup pnacl-abicheck pnacl-freeze
+subdirectories = bugpoint llc lli llvm-ar llvm-as llvm-bcanalyzer llvm-cov llvm-diff llvm-dis llvm-dwarfdump llvm-extract llvm-jitlistener llvm-link llvm-mc llvm-nm llvm-objdump llvm-prof llvm-ranlib llvm-rtdyld llvm-size macho-dump opt llvm-mcmarkup pnacl-abicheck pnacl-bcanalyzer pnacl-freeze pnacl-thaw
 
 [component_0]
 type = Group
diff --git a/tools/Makefile b/tools/Makefile
index f46e3b5fac..1940d7606c 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -34,8 +34,9 @@ PARALLEL_DIRS := opt llvm-as llvm-dis \
                  bugpoint llvm-bcanalyzer \
                  llvm-diff macho-dump llvm-objdump llvm-readobj \
 	         llvm-rtdyld llvm-dwarfdump llvm-cov \
-	         llvm-size llvm-stress llvm-mcmarkup bc-wrap pso-stub \
-	         llvm-symbolizer pnacl-abicheck pnacl-freeze pnacl-thaw
+                 llvm-size llvm-stress llvm-mcmarkup bc-wrap pso-stub \
+                 llvm-symbolizer pnacl-abicheck pnacl-bcanalyzer pnacl-freeze \
+                 pnacl-thaw
 
 # If Intel JIT Events support is configured, build an extra tool to test it.
 ifeq ($(USE_INTEL_JITEVENTS), 1)
diff --git a/tools/pnacl-bcanalyzer/CMakeLists.txt b/tools/pnacl-bcanalyzer/CMakeLists.txt
new file mode 100644
index 0000000000..0cf17b8886
--- /dev/null
+++ b/tools/pnacl-bcanalyzer/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS naclbitreader)
+
+add_llvm_tool(pnacl-bcanalyzer
+  pnacl-bcanalyzer.cpp
+  )
diff --git a/tools/pnacl-bcanalyzer/LLVMBuild.txt b/tools/pnacl-bcanalyzer/LLVMBuild.txt
new file mode 100644
index 0000000000..2944fca4b0
--- /dev/null
+++ b/tools/pnacl-bcanalyzer/LLVMBuild.txt
@@ -0,0 +1,22 @@
+;===- ./tools/pnacl-bcanalyzer/LLVMBuild.txt -------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Tool
+name = pnacl-bcanalyzer
+parent = Tools
+required_libraries = NaClBitReader
diff --git a/tools/pnacl-bcanalyzer/Makefile b/tools/pnacl-bcanalyzer/Makefile
new file mode 100644
index 0000000000..d3ec1a81a9
--- /dev/null
+++ b/tools/pnacl-bcanalyzer/Makefile
@@ -0,0 +1,17 @@
+##===- tools/pnacl-bcanalyzer/Makefile ---------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+LEVEL := ../..
+TOOLNAME := pnacl-bcanalyzer
+LINK_COMPONENTS := naclbitreader
+
+# This tool has no plugins, optimize startup time.
+TOOL_NO_EXPORTS := 1
+
+include $(LEVEL)/Makefile.common
diff --git a/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp b/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp
new file mode 100644
index 0000000000..7c542d79ae
--- /dev/null
+++ b/tools/pnacl-bcanalyzer/pnacl-bcanalyzer.cpp
@@ -0,0 +1,635 @@
+//===-- pnacl-bcanalyzer.cpp - Bitcode Analyzer -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tool may be invoked in the following manner:
+//  pnacl-bcanalyzer [options]      - Read frozen PNaCl bitcode from stdin
+//  pnacl-bcanalyzer [options] x.bc - Read frozen PNaCl bitcode from the x.bc
+//                                   file
+//
+//  Options:
+//      --help      - Output information about command line switches
+//      --dump      - Dump low-level bitcode structure in readable format
+//
+// This tool provides analytical information about a bitcode file. It is
+// intended as an aid to developers of bitcode reading and writing software. It
+// produces on std::out a summary of the bitcode file that shows various
+// statistics about the contents of the file. By default this information is
+// detailed and contains information about individual bitcode blocks and the
+// functions in the module.
+// The tool is also able to print a bitcode file in a straight forward text
+// format that shows the containment and relationships of the information in
+// the bitcode file (-dump option).
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Bitcode/NaCl/NaClBitstreamReader.h"
+#include "llvm/Bitcode/NaCl/NaClLLVMBitCodes.h"
+#include "llvm/Bitcode/NaCl/NaClReaderWriter.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include <algorithm>
+#include <map>
+using namespace llvm;
+
+static cl::opt<std::string>
+  InputFilename(cl::Positional, cl::desc("<input bitcode>"), cl::init("-"));
+
+static cl::opt<bool> Dump("dump", cl::desc("Dump low level bitcode trace"));
+
+//===----------------------------------------------------------------------===//
+// Bitcode specific analysis.
+//===----------------------------------------------------------------------===//
+
+static cl::opt<bool> NoHistogram("disable-histogram",
+                                 cl::desc("Do not print per-code histogram"));
+
+static cl::opt<bool>
+NonSymbolic("non-symbolic",
+            cl::desc("Emit numeric info in dump even if"
+                     " symbolic info is available"));
+
+namespace {
+
+/// CurStreamTypeType - A type for CurStreamType
+enum CurStreamTypeType {
+  UnknownBitstream,
+  LLVMIRBitstream
+};
+
+}
+
+/// CurStreamType - If we can sniff the flavor of this stream, we can produce
+/// better dump info.
+static CurStreamTypeType CurStreamType;
+
+
+/// GetBlockName - Return a symbolic block name if known, otherwise return
+/// null.
+static const char *GetBlockName(unsigned BlockID,
+                                const NaClBitstreamReader &StreamFile) {
+  // Standard blocks for all bitcode files.
+  if (BlockID < naclbitc::FIRST_APPLICATION_BLOCKID) {
+    if (BlockID == naclbitc::BLOCKINFO_BLOCK_ID)
+      return "BLOCKINFO_BLOCK";
+    return 0;
+  }
+
+  // Check to see if we have a blockinfo record for this block, with a name.
+  if (const NaClBitstreamReader::BlockInfo *Info =
+        StreamFile.getBlockInfo(BlockID)) {
+    if (!Info->Name.empty())
+      return Info->Name.c_str();
+  }
+
+
+  if (CurStreamType != LLVMIRBitstream) return 0;
+
+  switch (BlockID) {
+  default: return 0;
+  case naclbitc::MODULE_BLOCK_ID:          return "MODULE_BLOCK";
+  case naclbitc::PARAMATTR_BLOCK_ID:       return "PARAMATTR_BLOCK";
+  case naclbitc::PARAMATTR_GROUP_BLOCK_ID: return "PARAMATTR_GROUP_BLOCK_ID";
+  case naclbitc::TYPE_BLOCK_ID_NEW:        return "TYPE_BLOCK_ID";
+  case naclbitc::CONSTANTS_BLOCK_ID:       return "CONSTANTS_BLOCK";
+  case naclbitc::FUNCTION_BLOCK_ID:        return "FUNCTION_BLOCK";
+  case naclbitc::VALUE_SYMTAB_BLOCK_ID:    return "VALUE_SYMTAB";
+  case naclbitc::METADATA_BLOCK_ID:        return "METADATA_BLOCK";
+  case naclbitc::METADATA_ATTACHMENT_ID:   return "METADATA_ATTACHMENT_BLOCK";
+  case naclbitc::USELIST_BLOCK_ID:         return "USELIST_BLOCK_ID";
+  }
+}
+
+/// GetCodeName - Return a symbolic code name if known, otherwise return
+/// null.
+static const char *GetCodeName(unsigned CodeID, unsigned BlockID,
+                               const NaClBitstreamReader &StreamFile) {
+  // Standard blocks for all bitcode files.
+  if (BlockID < naclbitc::FIRST_APPLICATION_BLOCKID) {
+    if (BlockID == naclbitc::BLOCKINFO_BLOCK_ID) {
+      switch (CodeID) {
+      default: return 0;
+      case naclbitc::BLOCKINFO_CODE_SETBID:        return "SETBID";
+      case naclbitc::BLOCKINFO_CODE_BLOCKNAME:     return "BLOCKNAME";
+      case naclbitc::BLOCKINFO_CODE_SETRECORDNAME: return "SETRECORDNAME";
+      }
+    }
+    return 0;
+  }
+
+  // Check to see if we have a blockinfo record for this record, with a name.
+  if (const NaClBitstreamReader::BlockInfo *Info =
+        StreamFile.getBlockInfo(BlockID)) {
+    for (unsigned i = 0, e = Info->RecordNames.size(); i != e; ++i)
+      if (Info->RecordNames[i].first == CodeID)
+        return Info->RecordNames[i].second.c_str();
+  }
+
+
+  if (CurStreamType != LLVMIRBitstream) return 0;
+
+  switch (BlockID) {
+  default: return 0;
+  case naclbitc::MODULE_BLOCK_ID:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::MODULE_CODE_VERSION:     return "VERSION";
+    case naclbitc::MODULE_CODE_TRIPLE:      return "TRIPLE";
+    case naclbitc::MODULE_CODE_DATALAYOUT:  return "DATALAYOUT";
+    case naclbitc::MODULE_CODE_ASM:         return "ASM";
+    case naclbitc::MODULE_CODE_SECTIONNAME: return "SECTIONNAME";
+    case naclbitc::MODULE_CODE_DEPLIB:      return "DEPLIB"; // FIXME: Remove in 4.0
+    case naclbitc::MODULE_CODE_GLOBALVAR:   return "GLOBALVAR";
+    case naclbitc::MODULE_CODE_FUNCTION:    return "FUNCTION";
+    case naclbitc::MODULE_CODE_ALIAS:       return "ALIAS";
+    case naclbitc::MODULE_CODE_PURGEVALS:   return "PURGEVALS";
+    case naclbitc::MODULE_CODE_GCNAME:      return "GCNAME";
+    }
+  case naclbitc::PARAMATTR_BLOCK_ID:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::PARAMATTR_CODE_ENTRY_OLD: return "ENTRY";
+    case naclbitc::PARAMATTR_CODE_ENTRY:     return "ENTRY";
+    case naclbitc::PARAMATTR_GRP_CODE_ENTRY: return "ENTRY";
+    }
+  case naclbitc::TYPE_BLOCK_ID_NEW:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::TYPE_CODE_NUMENTRY:     return "NUMENTRY";
+    case naclbitc::TYPE_CODE_VOID:         return "VOID";
+    case naclbitc::TYPE_CODE_FLOAT:        return "FLOAT";
+    case naclbitc::TYPE_CODE_DOUBLE:       return "DOUBLE";
+    case naclbitc::TYPE_CODE_LABEL:        return "LABEL";
+    case naclbitc::TYPE_CODE_OPAQUE:       return "OPAQUE";
+    case naclbitc::TYPE_CODE_INTEGER:      return "INTEGER";
+    case naclbitc::TYPE_CODE_POINTER:      return "POINTER";
+    case naclbitc::TYPE_CODE_ARRAY:        return "ARRAY";
+    case naclbitc::TYPE_CODE_VECTOR:       return "VECTOR";
+    case naclbitc::TYPE_CODE_X86_FP80:     return "X86_FP80";
+    case naclbitc::TYPE_CODE_FP128:        return "FP128";
+    case naclbitc::TYPE_CODE_PPC_FP128:    return "PPC_FP128";
+    case naclbitc::TYPE_CODE_METADATA:     return "METADATA";
+    case naclbitc::TYPE_CODE_STRUCT_ANON:  return "STRUCT_ANON";
+    case naclbitc::TYPE_CODE_STRUCT_NAME:  return "STRUCT_NAME";
+    case naclbitc::TYPE_CODE_STRUCT_NAMED: return "STRUCT_NAMED";
+    case naclbitc::TYPE_CODE_FUNCTION:     return "FUNCTION";
+    }
+
+  case naclbitc::CONSTANTS_BLOCK_ID:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::CST_CODE_SETTYPE:         return "SETTYPE";
+    case naclbitc::CST_CODE_NULL:            return "NULL";
+    case naclbitc::CST_CODE_UNDEF:           return "UNDEF";
+    case naclbitc::CST_CODE_INTEGER:         return "INTEGER";
+    case naclbitc::CST_CODE_WIDE_INTEGER:    return "WIDE_INTEGER";
+    case naclbitc::CST_CODE_FLOAT:           return "FLOAT";
+    case naclbitc::CST_CODE_AGGREGATE:       return "AGGREGATE";
+    case naclbitc::CST_CODE_STRING:          return "STRING";
+    case naclbitc::CST_CODE_CSTRING:         return "CSTRING";
+    case naclbitc::CST_CODE_CE_BINOP:        return "CE_BINOP";
+    case naclbitc::CST_CODE_CE_CAST:         return "CE_CAST";
+    case naclbitc::CST_CODE_CE_GEP:          return "CE_GEP";
+    case naclbitc::CST_CODE_CE_INBOUNDS_GEP: return "CE_INBOUNDS_GEP";
+    case naclbitc::CST_CODE_CE_SELECT:       return "CE_SELECT";
+    case naclbitc::CST_CODE_CE_EXTRACTELT:   return "CE_EXTRACTELT";
+    case naclbitc::CST_CODE_CE_INSERTELT:    return "CE_INSERTELT";
+    case naclbitc::CST_CODE_CE_SHUFFLEVEC:   return "CE_SHUFFLEVEC";
+    case naclbitc::CST_CODE_CE_CMP:          return "CE_CMP";
+    case naclbitc::CST_CODE_INLINEASM:       return "INLINEASM";
+    case naclbitc::CST_CODE_CE_SHUFVEC_EX:   return "CE_SHUFVEC_EX";
+    case naclbitc::CST_CODE_BLOCKADDRESS:    return "CST_CODE_BLOCKADDRESS";
+    case naclbitc::CST_CODE_DATA:            return "DATA";
+    }
+  case naclbitc::FUNCTION_BLOCK_ID:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::FUNC_CODE_DECLAREBLOCKS: return "DECLAREBLOCKS";
+
+    case naclbitc::FUNC_CODE_INST_BINOP:        return "INST_BINOP";
+    case naclbitc::FUNC_CODE_INST_CAST:         return "INST_CAST";
+    case naclbitc::FUNC_CODE_INST_GEP:          return "INST_GEP";
+    case naclbitc::FUNC_CODE_INST_INBOUNDS_GEP: return "INST_INBOUNDS_GEP";
+    case naclbitc::FUNC_CODE_INST_SELECT:       return "INST_SELECT";
+    case naclbitc::FUNC_CODE_INST_EXTRACTELT:   return "INST_EXTRACTELT";
+    case naclbitc::FUNC_CODE_INST_INSERTELT:    return "INST_INSERTELT";
+    case naclbitc::FUNC_CODE_INST_SHUFFLEVEC:   return "INST_SHUFFLEVEC";
+    case naclbitc::FUNC_CODE_INST_CMP:          return "INST_CMP";
+
+    case naclbitc::FUNC_CODE_INST_RET:          return "INST_RET";
+    case naclbitc::FUNC_CODE_INST_BR:           return "INST_BR";
+    case naclbitc::FUNC_CODE_INST_SWITCH:       return "INST_SWITCH";
+    case naclbitc::FUNC_CODE_INST_INVOKE:       return "INST_INVOKE";
+    case naclbitc::FUNC_CODE_INST_UNREACHABLE:  return "INST_UNREACHABLE";
+
+    case naclbitc::FUNC_CODE_INST_PHI:          return "INST_PHI";
+    case naclbitc::FUNC_CODE_INST_ALLOCA:       return "INST_ALLOCA";
+    case naclbitc::FUNC_CODE_INST_LOAD:         return "INST_LOAD";
+    case naclbitc::FUNC_CODE_INST_VAARG:        return "INST_VAARG";
+    case naclbitc::FUNC_CODE_INST_STORE:        return "INST_STORE";
+    case naclbitc::FUNC_CODE_INST_EXTRACTVAL:   return "INST_EXTRACTVAL";
+    case naclbitc::FUNC_CODE_INST_INSERTVAL:    return "INST_INSERTVAL";
+    case naclbitc::FUNC_CODE_INST_CMP2:         return "INST_CMP2";
+    case naclbitc::FUNC_CODE_INST_VSELECT:      return "INST_VSELECT";
+    case naclbitc::FUNC_CODE_DEBUG_LOC_AGAIN:   return "DEBUG_LOC_AGAIN";
+    case naclbitc::FUNC_CODE_INST_CALL:         return "INST_CALL";
+    case naclbitc::FUNC_CODE_DEBUG_LOC:         return "DEBUG_LOC";
+    }
+  case naclbitc::VALUE_SYMTAB_BLOCK_ID:
+    switch (CodeID) {
+    default: return 0;
+    case naclbitc::VST_CODE_ENTRY: return "ENTRY";
+    case naclbitc::VST_CODE_BBENTRY: return "BBENTRY";
+    }
+  case naclbitc::METADATA_ATTACHMENT_ID:
+    switch(CodeID) {
+    default:return 0;
+    case naclbitc::METADATA_ATTACHMENT: return "METADATA_ATTACHMENT";
+    }
+  case naclbitc::METADATA_BLOCK_ID:
+    switch(CodeID) {
+    default:return 0;
+    case naclbitc::METADATA_STRING:      return "METADATA_STRING";
+    case naclbitc::METADATA_NAME:        return "METADATA_NAME";
+    case naclbitc::METADATA_KIND:        return "METADATA_KIND";
+    case naclbitc::METADATA_NODE:        return "METADATA_NODE";
+    case naclbitc::METADATA_FN_NODE:     return "METADATA_FN_NODE";
+    case naclbitc::METADATA_NAMED_NODE:  return "METADATA_NAMED_NODE";
+    }
+  case naclbitc::USELIST_BLOCK_ID:
+    switch(CodeID) {
+    default:return 0;
+    case naclbitc::USELIST_CODE_ENTRY:   return "USELIST_CODE_ENTRY";
+    }
+  }
+}
+
+struct PerRecordStats {
+  unsigned NumInstances;
+  unsigned NumAbbrev;
+  uint64_t TotalBits;
+
+  PerRecordStats() : NumInstances(0), NumAbbrev(0), TotalBits(0) {}
+};
+
+struct PerBlockIDStats {
+  /// NumInstances - This the number of times this block ID has been seen.
+  unsigned NumInstances;
+
+  /// NumBits - The total size in bits of all of these blocks.
+  uint64_t NumBits;
+
+  /// NumSubBlocks - The total number of blocks these blocks contain.
+  unsigned NumSubBlocks;
+
+  /// NumAbbrevs - The total number of abbreviations.
+  unsigned NumAbbrevs;
+
+  /// NumRecords - The total number of records these blocks contain, and the
+  /// number that are abbreviated.
+  unsigned NumRecords, NumAbbreviatedRecords;
+
+  /// CodeFreq - Keep track of the number of times we see each code.
+  std::vector<PerRecordStats> CodeFreq;
+
+  PerBlockIDStats()
+    : NumInstances(0), NumBits(0),
+      NumSubBlocks(0), NumAbbrevs(0), NumRecords(0), NumAbbreviatedRecords(0) {}
+};
+
+static std::map<unsigned, PerBlockIDStats> BlockIDStats;
+
+
+
+/// Error - All bitcode analysis errors go through this function, making this a
+/// good place to breakpoint if debugging.
+static bool Error(const std::string &Err) {
+  errs() << Err << "\n";
+  return true;
+}
+
+/// ParseBlock - Read a block, updating statistics, etc.
+static bool ParseBlock(NaClBitstreamCursor &Stream, unsigned BlockID,
+                       unsigned IndentLevel) {
+  std::string Indent(IndentLevel*2, ' ');
+  uint64_t BlockBitStart = Stream.GetCurrentBitNo();
+
+  // Get the statistics for this BlockID.
+  PerBlockIDStats &BlockStats = BlockIDStats[BlockID];
+
+  BlockStats.NumInstances++;
+
+  // BLOCKINFO is a special part of the stream.
+  if (BlockID == naclbitc::BLOCKINFO_BLOCK_ID) {
+    if (Dump) outs() << Indent << "<BLOCKINFO_BLOCK/>\n";
+    if (Stream.ReadBlockInfoBlock())
+      return Error("Malformed BlockInfoBlock");
+    uint64_t BlockBitEnd = Stream.GetCurrentBitNo();
+    BlockStats.NumBits += BlockBitEnd-BlockBitStart;
+    return false;
+  }
+
+  unsigned NumWords = 0;
+  if (Stream.EnterSubBlock(BlockID, &NumWords))
+    return Error("Malformed block record");
+
+  const char *BlockName = 0;
+  if (Dump) {
+    outs() << Indent << "<";
+    if ((BlockName = GetBlockName(BlockID, *Stream.getBitStreamReader())))
+      outs() << BlockName;
+    else
+      outs() << "UnknownBlock" << BlockID;
+
+    if (NonSymbolic && BlockName)
+      outs() << " BlockID=" << BlockID;
+
+    outs() << " NumWords=" << NumWords
+           << " BlockCodeSize=" << Stream.getAbbrevIDWidth() << ">\n";
+  }
+
+  SmallVector<uint64_t, 64> Record;
+
+  // Read all the records for this block.
+  while (1) {
+    if (Stream.AtEndOfStream())
+      return Error("Premature end of bitstream");
+
+    uint64_t RecordStartBit = Stream.GetCurrentBitNo();
+
+    NaClBitstreamEntry Entry =
+      Stream.advance(NaClBitstreamCursor::AF_DontAutoprocessAbbrevs);
+    
+    switch (Entry.Kind) {
+    case NaClBitstreamEntry::Error:
+      return Error("malformed bitcode file");
+    case NaClBitstreamEntry::EndBlock: {
+      uint64_t BlockBitEnd = Stream.GetCurrentBitNo();
+      BlockStats.NumBits += BlockBitEnd-BlockBitStart;
+      if (Dump) {
+        outs() << Indent << "</";
+        if (BlockName)
+          outs() << BlockName << ">\n";
+        else
+          outs() << "UnknownBlock" << BlockID << ">\n";
+      }
+      return false;
+    }
+        
+    case NaClBitstreamEntry::SubBlock: {
+      uint64_t SubBlockBitStart = Stream.GetCurrentBitNo();
+      if (ParseBlock(Stream, Entry.ID, IndentLevel+1))
+        return true;
+      ++BlockStats.NumSubBlocks;
+      uint64_t SubBlockBitEnd = Stream.GetCurrentBitNo();
+      
+      // Don't include subblock sizes in the size of this block.
+      BlockBitStart += SubBlockBitEnd-SubBlockBitStart;
+      continue;
+    }
+    case NaClBitstreamEntry::Record:
+      // The interesting case.
+      break;
+    }
+
+    if (Entry.ID == naclbitc::DEFINE_ABBREV) {
+      Stream.ReadAbbrevRecord();
+      ++BlockStats.NumAbbrevs;
+      continue;
+    }
+    
+    Record.clear();
+
+    ++BlockStats.NumRecords;
+
+    StringRef Blob;
+    unsigned Code = Stream.readRecord(Entry.ID, Record, &Blob);
+
+    // Increment the # occurrences of this code.
+    if (BlockStats.CodeFreq.size() <= Code)
+      BlockStats.CodeFreq.resize(Code+1);
+    BlockStats.CodeFreq[Code].NumInstances++;
+    BlockStats.CodeFreq[Code].TotalBits +=
+      Stream.GetCurrentBitNo()-RecordStartBit;
+    if (Entry.ID != naclbitc::UNABBREV_RECORD) {
+      BlockStats.CodeFreq[Code].NumAbbrev++;
+      ++BlockStats.NumAbbreviatedRecords;
+    }
+
+    if (Dump) {
+      outs() << Indent << "  <";
+      if (const char *CodeName =
+            GetCodeName(Code, BlockID, *Stream.getBitStreamReader()))
+        outs() << CodeName;
+      else
+        outs() << "UnknownCode" << Code;
+      if (NonSymbolic &&
+          GetCodeName(Code, BlockID, *Stream.getBitStreamReader()))
+        outs() << " codeid=" << Code;
+      if (Entry.ID != naclbitc::UNABBREV_RECORD)
+        outs() << " abbrevid=" << Entry.ID;
+
+      for (unsigned i = 0, e = Record.size(); i != e; ++i)
+        outs() << " op" << i << "=" << (int64_t)Record[i];
+
+      outs() << "/>";
+
+      if (Blob.data()) {
+        outs() << " blob data = ";
+        bool BlobIsPrintable = true;
+        for (unsigned i = 0, e = Blob.size(); i != e; ++i)
+          if (!isprint(static_cast<unsigned char>(Blob[i]))) {
+            BlobIsPrintable = false;
+            break;
+          }
+
+        if (BlobIsPrintable)
+          outs() << "'" << Blob << "'";
+        else
+          outs() << "unprintable, " << Blob.size() << " bytes.";
+      }
+
+      outs() << "\n";
+    }
+  }
+}
+
+static void PrintSize(double Bits) {
+  outs() << format("%.2f/%.2fB/%luW", Bits, Bits/8,(unsigned long)(Bits/32));
+}
+static void PrintSize(uint64_t Bits) {
+  outs() << format("%lub/%.2fB/%luW", (unsigned long)Bits,
+                   (double)Bits/8, (unsigned long)(Bits/32));
+}
+
+
+/// AnalyzeBitcode - Analyze the bitcode file specified by InputFilename.
+static int AnalyzeBitcode() {
+  // Read the input file.
+  OwningPtr<MemoryBuffer> MemBuf;
+
+  if (error_code ec =
+        MemoryBuffer::getFileOrSTDIN(InputFilename.c_str(), MemBuf))
+    return Error("Error reading '" + InputFilename + "': " + ec.message());
+
+  if (MemBuf->getBufferSize() & 3)
+    return Error("Bitcode stream should be a multiple of 4 bytes in length");
+
+  const unsigned char *BufPtr = (const unsigned char *)MemBuf->getBufferStart();
+  const unsigned char *EndBufPtr = BufPtr+MemBuf->getBufferSize();
+
+  // If we have a wrapper header, parse it and ignore the non-bc file contents.
+  // The magic number is 0x0B17C0DE stored in little endian.
+  if (isNaClBitcodeWrapper(BufPtr, EndBufPtr))
+    if (SkipNaClBitcodeWrapperHeader(BufPtr, EndBufPtr, true))
+      return Error("Invalid bitcode wrapper header");
+
+  NaClBitstreamReader StreamFile(BufPtr, EndBufPtr);
+  NaClBitstreamCursor Stream(StreamFile);
+  StreamFile.CollectBlockInfoNames();
+
+  // Read the stream signature.
+  char Signature[6];
+  Signature[0] = Stream.Read(8);
+  Signature[1] = Stream.Read(8);
+  Signature[2] = Stream.Read(4);
+  Signature[3] = Stream.Read(4);
+  Signature[4] = Stream.Read(4);
+  Signature[5] = Stream.Read(4);
+
+  // Autodetect the file contents, if it is one we know.
+  CurStreamType = UnknownBitstream;
+  if (Signature[0] == 'B' && Signature[1] == 'C' &&
+      Signature[2] == 0x0 && Signature[3] == 0xC &&
+      Signature[4] == 0xE && Signature[5] == 0xD)
+    CurStreamType = LLVMIRBitstream;
+
+  unsigned NumTopBlocks = 0;
+
+  // Parse the top-level structure.  We only allow blocks at the top-level.
+  while (!Stream.AtEndOfStream()) {
+    unsigned Code = Stream.ReadCode();
+    if (Code != naclbitc::ENTER_SUBBLOCK)
+      return Error("Invalid record at top-level");
+
+    unsigned BlockID = Stream.ReadSubBlockID();
+
+    if (ParseBlock(Stream, BlockID, 0))
+      return true;
+    ++NumTopBlocks;
+  }
+
+  if (Dump) outs() << "\n\n";
+
+  uint64_t BufferSizeBits = (EndBufPtr-BufPtr)*CHAR_BIT;
+  // Print a summary of the read file.
+  outs() << "Summary of " << InputFilename << ":\n";
+  outs() << "         Total size: ";
+  PrintSize(BufferSizeBits);
+  outs() << "\n";
+  outs() << "        Stream type: ";
+  switch (CurStreamType) {
+  case UnknownBitstream: outs() << "unknown\n"; break;
+  case LLVMIRBitstream:  outs() << "LLVM IR\n"; break;
+  }
+  outs() << "  # Toplevel Blocks: " << NumTopBlocks << "\n";
+  outs() << "\n";
+
+  // Emit per-block stats.
+  outs() << "Per-block Summary:\n";
+  for (std::map<unsigned, PerBlockIDStats>::iterator I = BlockIDStats.begin(),
+       E = BlockIDStats.end(); I != E; ++I) {
+    outs() << "  Block ID #" << I->first;
+    if (const char *BlockName = GetBlockName(I->first, StreamFile))
+      outs() << " (" << BlockName << ")";
+    outs() << ":\n";
+
+    const PerBlockIDStats &Stats = I->second;
+    outs() << "      Num Instances: " << Stats.NumInstances << "\n";
+    outs() << "         Total Size: ";
+    PrintSize(Stats.NumBits);
+    outs() << "\n";
+    double pct = (Stats.NumBits * 100.0) / BufferSizeBits;
+    outs() << "    Percent of file: " << format("%2.4f%%", pct) << "\n";
+    if (Stats.NumInstances > 1) {
+      outs() << "       Average Size: ";
+      PrintSize(Stats.NumBits/(double)Stats.NumInstances);
+      outs() << "\n";
+      outs() << "  Tot/Avg SubBlocks: " << Stats.NumSubBlocks << "/"
+             << Stats.NumSubBlocks/(double)Stats.NumInstances << "\n";
+      outs() << "    Tot/Avg Abbrevs: " << Stats.NumAbbrevs << "/"
+             << Stats.NumAbbrevs/(double)Stats.NumInstances << "\n";
+      outs() << "    Tot/Avg Records: " << Stats.NumRecords << "/"
+             << Stats.NumRecords/(double)Stats.NumInstances << "\n";
+    } else {
+      outs() << "      Num SubBlocks: " << Stats.NumSubBlocks << "\n";
+      outs() << "        Num Abbrevs: " << Stats.NumAbbrevs << "\n";
+      outs() << "        Num Records: " << Stats.NumRecords << "\n";
+    }
+    if (Stats.NumRecords) {
+      double pct = (Stats.NumAbbreviatedRecords * 100.0) / Stats.NumRecords;
+      outs() << "    Percent Abbrevs: " << format("%2.4f%%", pct) << "\n";
+    }
+    outs() << "\n";
+
+    // Print a histogram of the codes we see.
+    if (!NoHistogram && !Stats.CodeFreq.empty()) {
+      std::vector<std::pair<unsigned, unsigned> > FreqPairs;  // <freq,code>
+      for (unsigned i = 0, e = Stats.CodeFreq.size(); i != e; ++i)
+        if (unsigned Freq = Stats.CodeFreq[i].NumInstances)
+          FreqPairs.push_back(std::make_pair(Freq, i));
+      std::stable_sort(FreqPairs.begin(), FreqPairs.end());
+      std::reverse(FreqPairs.begin(), FreqPairs.end());
+
+      outs() << "\tRecord Histogram:\n";
+      outs() << "\t\t  Count    # Bits   %% Abv  Record Kind\n";
+      for (unsigned i = 0, e = FreqPairs.size(); i != e; ++i) {
+        const PerRecordStats &RecStats = Stats.CodeFreq[FreqPairs[i].second];
+
+        outs() << format("\t\t%7d %9lu",
+                         RecStats.NumInstances,
+                         (unsigned long)RecStats.TotalBits);
+
+        if (RecStats.NumAbbrev)
+          outs() <<
+              format("%7.2f  ",
+                     (double)RecStats.NumAbbrev/RecStats.NumInstances*100);
+        else
+          outs() << "         ";
+
+        if (const char *CodeName =
+              GetCodeName(FreqPairs[i].second, I->first, StreamFile))
+          outs() << CodeName << "\n";
+        else
+          outs() << "UnknownCode" << FreqPairs[i].second << "\n";
+      }
+      outs() << "\n";
+
+    }
+  }
+  return 0;
+}
+
+
+int main(int argc, char **argv) {
+  // Print a stack trace if we signal out.
+  sys::PrintStackTraceOnErrorSignal();
+  PrettyStackTraceProgram X(argc, argv);
+  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+  cl::ParseCommandLineOptions(argc, argv, "pnacl-bcanalyzer file analyzer\n");
+
+  return AnalyzeBitcode();
+}