tools/llvm-symbolizer/llvm-symbolizer.cpp - fp2-dev/platform/external/llvm - Gitiles

 //===-- llvm-symbolizer.cpp - Simple addr2line-like symbolizer ------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This utility works much like "addr2line". It is able of transforming
 // tuples (module name, module offset) to code locations (function name,
 // file, line number, column number). It is targeted for compiler-rt tools
 // (especially AddressSanitizer and ThreadSanitizer) that can use it
 // to symbolize stack traces in their error reports.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/DebugInfo/DIContext.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/raw_ostream.h"

 #include <cstdio>
 #include <cstring>
 #include <map>
 #include <string>

 using namespace llvm;
 using namespace object;

 static cl::opt<bool>
 UseSymbolTable("use-symbol-table", cl::init(true),
                cl::desc("Prefer names in symbol table to names "
                         "in debug info"));

 static cl::opt<bool>
 PrintFunctions("functions", cl::init(true),
                cl::desc("Print function names as well as line "
                         "information for a given address"));

 static cl::opt<bool>
 PrintInlining("inlining", cl::init(true),
               cl::desc("Print all inlined frames for a given address"));

 static cl::opt<bool>
 Demangle("demangle", cl::init(true),
          cl::desc("Demangle function names"));

 static StringRef ToolInvocationPath;

 static bool error(error_code ec) {
   if (!ec) return false;
   errs() << ToolInvocationPath << ": error reading file: "
          << ec.message() << ".\n";
   return true;
 }

 static uint32_t getDILineInfoSpecifierFlags() {
   uint32_t Flags = llvm::DILineInfoSpecifier::FileLineInfo |
                    llvm::DILineInfoSpecifier::AbsoluteFilePath;
   if (PrintFunctions)
     Flags |= llvm::DILineInfoSpecifier::FunctionName;
   return Flags;
 }

 static void patchFunctionNameInDILineInfo(const std::string &NewFunctionName,
                                           DILineInfo &LineInfo) {
   std::string FileName = LineInfo.getFileName();
   LineInfo = DILineInfo(StringRef(FileName), StringRef(NewFunctionName),
                         LineInfo.getLine(), LineInfo.getColumn());
 }

 namespace {
 class ModuleInfo {
   OwningPtr<ObjectFile> Module;
   OwningPtr<DIContext> DebugInfoContext;
  public:
   ModuleInfo(ObjectFile *Obj, DIContext *DICtx)
       : Module(Obj), DebugInfoContext(DICtx) {}

   DILineInfo symbolizeCode(uint64_t ModuleOffset) const {
     DILineInfo LineInfo;
     if (DebugInfoContext) {
       LineInfo = DebugInfoContext->getLineInfoForAddress(
           ModuleOffset, getDILineInfoSpecifierFlags());
     }
     // Override function name from symbol table if necessary.
     if (PrintFunctions && UseSymbolTable) {
       std::string Function;
       if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
         patchFunctionNameInDILineInfo(Function, LineInfo);
       }
     }
     return LineInfo;
   }

   DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset) const {
     DIInliningInfo InlinedContext;
     if (DebugInfoContext) {
       InlinedContext = DebugInfoContext->getInliningInfoForAddress(
           ModuleOffset, getDILineInfoSpecifierFlags());
     }
     // Make sure there is at least one frame in context.
     if (InlinedContext.getNumberOfFrames() == 0) {
       InlinedContext.addFrame(DILineInfo());
     }
     // Override the function name in lower frame with name from symbol table.
     if (PrintFunctions && UseSymbolTable) {
       DIInliningInfo PatchedInlinedContext;
       for (uint32_t i = 0, n = InlinedContext.getNumberOfFrames();
            i != n; i++) {
         DILineInfo LineInfo = InlinedContext.getFrame(i);
         if (i == n - 1) {
           std::string Function;
           if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
             patchFunctionNameInDILineInfo(Function, LineInfo);
           }
         }
         PatchedInlinedContext.addFrame(LineInfo);
       }
       InlinedContext = PatchedInlinedContext;
     }
     return InlinedContext;
   }

  private:
   bool getFunctionNameFromSymbolTable(uint64_t Address,
                                       std::string &FunctionName) const {
     assert(Module);
     error_code ec;
     for (symbol_iterator si = Module->begin_symbols(),
                          se = Module->end_symbols();
                          si != se; si.increment(ec)) {
       if (error(ec)) return false;
       uint64_t SymbolAddress;
       uint64_t SymbolSize;
       SymbolRef::Type SymbolType;
       if (error(si->getAddress(SymbolAddress)) ||
           SymbolAddress == UnknownAddressOrSize) continue;
       if (error(si->getSize(SymbolSize)) ||
           SymbolSize == UnknownAddressOrSize) continue;
       if (error(si->getType(SymbolType))) continue;
       // FIXME: If a function has alias, there are two entries in symbol table
       // with same address size. Make sure we choose the correct one.
       if (SymbolAddress <= Address && Address < SymbolAddress + SymbolSize &&
           SymbolType == SymbolRef::ST_Function) {
         StringRef Name;
         if (error(si->getName(Name))) continue;
         FunctionName = Name.str();
         return true;
       }
     }
     return false;
   }
 };

 typedef std::map<std::string, ModuleInfo*> ModuleMapTy;
 typedef ModuleMapTy::iterator ModuleMapIter;
 }  // namespace

 static ModuleMapTy Modules;

 static bool isFullNameOfDwarfSection(const StringRef &FullName,
                                      const StringRef &ShortName) {
   static const char kDwarfPrefix[] = "__DWARF,";
   StringRef Name = FullName;
   // Skip "__DWARF," prefix.
   if (Name.startswith(kDwarfPrefix))
     Name = Name.substr(strlen(kDwarfPrefix));
   // Skip . and _ prefixes.
   Name = Name.substr(Name.find_first_not_of("._"));
   return (Name == ShortName);
 }

 // Returns true if the object endianness is known.
 static bool getObjectEndianness(const ObjectFile *Obj,
                                 bool &IsLittleEndian) {
   // FIXME: Implement this when libLLVMObject allows to do it easily.
   IsLittleEndian = true;
   return true;
 }

 static void getDebugInfoSections(const ObjectFile *Obj,
                                  StringRef &DebugInfoSection,
                                  StringRef &DebugAbbrevSection,
                                  StringRef &DebugLineSection,
                                  StringRef &DebugArangesSection,
                                  StringRef &DebugStringSection,
                                  StringRef &DebugRangesSection) {
   if (Obj == 0)
     return;
   error_code ec;
   for (section_iterator i = Obj->begin_sections(),
                         e = Obj->end_sections();
                         i != e; i.increment(ec)) {
     if (error(ec)) break;
     StringRef Name;
     if (error(i->getName(Name))) continue;
     StringRef Data;
     if (error(i->getContents(Data))) continue;
     if (isFullNameOfDwarfSection(Name, "debug_info"))
       DebugInfoSection = Data;
     else if (isFullNameOfDwarfSection(Name, "debug_abbrev"))
       DebugAbbrevSection = Data;
     else if (isFullNameOfDwarfSection(Name, "debug_line"))
       DebugLineSection = Data;
     // Don't use debug_aranges for now, as address ranges contained
     // there may not cover all instructions in the module
     // else if (isFullNameOfDwarfSection(Name, "debug_aranges"))
     //   DebugArangesSection = Data;
     else if (isFullNameOfDwarfSection(Name, "debug_str"))
       DebugStringSection = Data;
     else if (isFullNameOfDwarfSection(Name, "debug_ranges"))
       DebugRangesSection = Data;
   }
 }

 static ObjectFile *getObjectFile(const std::string &Path) {
   OwningPtr<MemoryBuffer> Buff;
   MemoryBuffer::getFile(Path, Buff);
   return ObjectFile::createObjectFile(Buff.take());
 }

 static std::string getDarwinDWARFResourceForModule(const std::string &Path) {
   StringRef Basename = sys::path::filename(Path);
   const std::string &DSymDirectory = Path + ".dSYM";
   SmallString<16> ResourceName = StringRef(DSymDirectory);
   sys::path::append(ResourceName, "Contents", "Resources", "DWARF");
   sys::path::append(ResourceName, Basename);
   return ResourceName.str();
 }

 static ModuleInfo *getOrCreateModuleInfo(const std::string &ModuleName) {
   ModuleMapIter I = Modules.find(ModuleName);
   if (I != Modules.end())
     return I->second;

   ObjectFile *Obj = getObjectFile(ModuleName);
   if (Obj == 0) {
     // Module name doesn't point to a valid object file.
     Modules.insert(make_pair(ModuleName, (ModuleInfo*)0));
     return 0;
   }

   DIContext *Context = 0;
   bool IsLittleEndian;
   if (getObjectEndianness(Obj, IsLittleEndian)) {
     StringRef DebugInfo;
     StringRef DebugAbbrev;
     StringRef DebugLine;
     StringRef DebugAranges;
     StringRef DebugString;
     StringRef DebugRanges;
     getDebugInfoSections(Obj, DebugInfo, DebugAbbrev, DebugLine,
                          DebugAranges, DebugString, DebugRanges);

     // On Darwin we may find DWARF in separate object file in
     // resource directory.
     if (isa<MachOObjectFile>(Obj)) {
       const std::string &ResourceName = getDarwinDWARFResourceForModule(
           ModuleName);
       ObjectFile *ResourceObj = getObjectFile(ResourceName);
       if (ResourceObj != 0)
         getDebugInfoSections(ResourceObj, DebugInfo, DebugAbbrev, DebugLine,
                              DebugAranges, DebugString, DebugRanges);
     }

     Context = DIContext::getDWARFContext(
         IsLittleEndian, DebugInfo, DebugAbbrev,
         DebugAranges, DebugLine, DebugString,
         DebugRanges);
     assert(Context);
   }

   ModuleInfo *Info = new ModuleInfo(Obj, Context);
   Modules.insert(make_pair(ModuleName, Info));
   return Info;
 }

 // Assume that __cxa_demangle is provided by libcxxabi.
 extern "C" char *__cxa_demangle(const char *mangled_name, char *output_buffer,
                                 size_t *length, int *status);

 static void printDILineInfo(DILineInfo LineInfo) {
   // By default, DILineInfo contains "<invalid>" for function/filename it
   // cannot fetch. We replace it to "??" to make our output closer to addr2line.
   static const std::string kDILineInfoBadString = "<invalid>";
   static const std::string kSymbolizerBadString = "??";
   if (PrintFunctions) {
     std::string FunctionName = LineInfo.getFunctionName();
     if (FunctionName == kDILineInfoBadString)
       FunctionName = kSymbolizerBadString;
     if (Demangle) {
       int status = 0;
       char *DemangledName = __cxa_demangle(
           FunctionName.c_str(), 0, 0, &status);
       if (status == 0) {
         FunctionName = DemangledName;
         free(DemangledName);
       }
     }
     outs() << FunctionName << "\n";
   }
   std::string Filename = LineInfo.getFileName();
   if (Filename == kDILineInfoBadString)
     Filename = kSymbolizerBadString;
   outs() << Filename <<
          ":" << LineInfo.getLine() <<
          ":" << LineInfo.getColumn() <<
          "\n";
 }

 static void symbolize(std::string ModuleName, std::string ModuleOffsetStr) {
   ModuleInfo *Info = getOrCreateModuleInfo(ModuleName);
   uint64_t Offset = 0;
   if (Info == 0 ||
       StringRef(ModuleOffsetStr).getAsInteger(0, Offset)) {
     printDILineInfo(DILineInfo());
   } else if (PrintInlining) {
     DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(Offset);
     uint32_t FramesNum = InlinedContext.getNumberOfFrames();
     assert(FramesNum > 0);
     for (uint32_t i = 0; i < FramesNum; i++) {
       DILineInfo LineInfo = InlinedContext.getFrame(i);
       printDILineInfo(LineInfo);
     }
   } else {
     DILineInfo LineInfo = Info->symbolizeCode(Offset);
     printDILineInfo(LineInfo);
   }

   outs() << "\n";  // Print extra empty line to mark the end of output.
   outs().flush();
 }

 static bool parseModuleNameAndOffset(std::string &ModuleName,
                                      std::string &ModuleOffsetStr) {
   static const int kMaxInputStringLength = 1024;
   static const char kDelimiters[] = " \n";
   char InputString[kMaxInputStringLength];
   if (!fgets(InputString, sizeof(InputString), stdin))
     return false;
   ModuleName = "";
   ModuleOffsetStr = "";
   // FIXME: Handle case when filename is given in quotes.
   if (char *FilePath = strtok(InputString, kDelimiters)) {
     ModuleName = FilePath;
     if (char *OffsetStr = strtok((char*)0, kDelimiters))
       ModuleOffsetStr = OffsetStr;
   }
   return true;
 }

 int main(int argc, char **argv) {
   // Print 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, "llvm symbolizer for compiler-rt\n");
   ToolInvocationPath = argv[0];

   std::string ModuleName;
   std::string ModuleOffsetStr;
   while (parseModuleNameAndOffset(ModuleName, ModuleOffsetStr)) {
     symbolize(ModuleName, ModuleOffsetStr);
   }
   return 0;
 }
	//===-- llvm-symbolizer.cpp - Simple addr2line-like symbolizer ------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This utility works much like "addr2line". It is able of transforming
	// tuples (module name, module offset) to code locations (function name,
	// file, line number, column number). It is targeted for compiler-rt tools
	// (especially AddressSanitizer and ThreadSanitizer) that can use it
	// to symbolize stack traces in their error reports.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/ADT/OwningPtr.h"
	#include "llvm/ADT/StringRef.h"
	#include "llvm/DebugInfo/DIContext.h"
	#include "llvm/Object/MachO.h"
	#include "llvm/Object/ObjectFile.h"
	#include "llvm/Support/Casting.h"
	#include "llvm/Support/CommandLine.h"
	#include "llvm/Support/Debug.h"
	#include "llvm/Support/ManagedStatic.h"
	#include "llvm/Support/MemoryBuffer.h"
	#include "llvm/Support/Path.h"
	#include "llvm/Support/PrettyStackTrace.h"
	#include "llvm/Support/Signals.h"
	#include "llvm/Support/raw_ostream.h"

	#include <cstdio>
	#include <cstring>
	#include <map>
	#include <string>

	using namespace llvm;
	using namespace object;

	static cl::opt<bool>
	UseSymbolTable("use-symbol-table", cl::init(true),
	cl::desc("Prefer names in symbol table to names "
	"in debug info"));

	static cl::opt<bool>
	PrintFunctions("functions", cl::init(true),
	cl::desc("Print function names as well as line "
	"information for a given address"));

	static cl::opt<bool>
	PrintInlining("inlining", cl::init(true),
	cl::desc("Print all inlined frames for a given address"));

	static cl::opt<bool>
	Demangle("demangle", cl::init(true),
	cl::desc("Demangle function names"));

	static StringRef ToolInvocationPath;

	static bool error(error_code ec) {
	if (!ec) return false;
	errs() << ToolInvocationPath << ": error reading file: "
	<< ec.message() << ".\n";
	return true;
	}

	static uint32_t getDILineInfoSpecifierFlags() {
	uint32_t Flags = llvm::DILineInfoSpecifier::FileLineInfo \|
	llvm::DILineInfoSpecifier::AbsoluteFilePath;
	if (PrintFunctions)
	Flags \|= llvm::DILineInfoSpecifier::FunctionName;
	return Flags;
	}

	static void patchFunctionNameInDILineInfo(const std::string &NewFunctionName,
	DILineInfo &LineInfo) {
	std::string FileName = LineInfo.getFileName();
	LineInfo = DILineInfo(StringRef(FileName), StringRef(NewFunctionName),
	LineInfo.getLine(), LineInfo.getColumn());
	}

	namespace {
	class ModuleInfo {
	OwningPtr<ObjectFile> Module;
	OwningPtr<DIContext> DebugInfoContext;
	public:
	ModuleInfo(ObjectFile Obj, DIContext DICtx)
	: Module(Obj), DebugInfoContext(DICtx) {}

	DILineInfo symbolizeCode(uint64_t ModuleOffset) const {
	DILineInfo LineInfo;
	if (DebugInfoContext) {
	LineInfo = DebugInfoContext->getLineInfoForAddress(
	ModuleOffset, getDILineInfoSpecifierFlags());
	}
	// Override function name from symbol table if necessary.
	if (PrintFunctions && UseSymbolTable) {
	std::string Function;
	if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
	patchFunctionNameInDILineInfo(Function, LineInfo);
	}
	}
	return LineInfo;
	}

	DIInliningInfo symbolizeInlinedCode(uint64_t ModuleOffset) const {
	DIInliningInfo InlinedContext;
	if (DebugInfoContext) {
	InlinedContext = DebugInfoContext->getInliningInfoForAddress(
	ModuleOffset, getDILineInfoSpecifierFlags());
	}
	// Make sure there is at least one frame in context.
	if (InlinedContext.getNumberOfFrames() == 0) {
	InlinedContext.addFrame(DILineInfo());
	}
	// Override the function name in lower frame with name from symbol table.
	if (PrintFunctions && UseSymbolTable) {
	DIInliningInfo PatchedInlinedContext;
	for (uint32_t i = 0, n = InlinedContext.getNumberOfFrames();
	i != n; i++) {
	DILineInfo LineInfo = InlinedContext.getFrame(i);
	if (i == n - 1) {
	std::string Function;
	if (getFunctionNameFromSymbolTable(ModuleOffset, Function)) {
	patchFunctionNameInDILineInfo(Function, LineInfo);
	}
	}
	PatchedInlinedContext.addFrame(LineInfo);
	}
	InlinedContext = PatchedInlinedContext;
	}
	return InlinedContext;
	}

	private:
	bool getFunctionNameFromSymbolTable(uint64_t Address,
	std::string &FunctionName) const {
	assert(Module);
	error_code ec;
	for (symbol_iterator si = Module->begin_symbols(),
	se = Module->end_symbols();
	si != se; si.increment(ec)) {
	if (error(ec)) return false;
	uint64_t SymbolAddress;
	uint64_t SymbolSize;
	SymbolRef::Type SymbolType;
	if (error(si->getAddress(SymbolAddress)) \|\|
	SymbolAddress == UnknownAddressOrSize) continue;
	if (error(si->getSize(SymbolSize)) \|\|
	SymbolSize == UnknownAddressOrSize) continue;
	if (error(si->getType(SymbolType))) continue;
	// FIXME: If a function has alias, there are two entries in symbol table
	// with same address size. Make sure we choose the correct one.
	if (SymbolAddress <= Address && Address < SymbolAddress + SymbolSize &&
	SymbolType == SymbolRef::ST_Function) {
	StringRef Name;
	if (error(si->getName(Name))) continue;
	FunctionName = Name.str();
	return true;
	}
	}
	return false;
	}
	};

	typedef std::map<std::string, ModuleInfo*> ModuleMapTy;
	typedef ModuleMapTy::iterator ModuleMapIter;
	} // namespace

	static ModuleMapTy Modules;

	static bool isFullNameOfDwarfSection(const StringRef &FullName,
	const StringRef &ShortName) {
	static const char kDwarfPrefix[] = "__DWARF,";
	StringRef Name = FullName;
	// Skip "__DWARF," prefix.
	if (Name.startswith(kDwarfPrefix))
	Name = Name.substr(strlen(kDwarfPrefix));
	// Skip . and _ prefixes.
	Name = Name.substr(Name.find_first_not_of("._"));
	return (Name == ShortName);
	}

	// Returns true if the object endianness is known.
	static bool getObjectEndianness(const ObjectFile *Obj,
	bool &IsLittleEndian) {
	// FIXME: Implement this when libLLVMObject allows to do it easily.
	IsLittleEndian = true;
	return true;
	}

	static void getDebugInfoSections(const ObjectFile *Obj,
	StringRef &DebugInfoSection,
	StringRef &DebugAbbrevSection,
	StringRef &DebugLineSection,
	StringRef &DebugArangesSection,
	StringRef &DebugStringSection,
	StringRef &DebugRangesSection) {
	if (Obj == 0)
	return;
	error_code ec;
	for (section_iterator i = Obj->begin_sections(),
	e = Obj->end_sections();
	i != e; i.increment(ec)) {
	if (error(ec)) break;
	StringRef Name;
	if (error(i->getName(Name))) continue;
	StringRef Data;
	if (error(i->getContents(Data))) continue;
	if (isFullNameOfDwarfSection(Name, "debug_info"))
	DebugInfoSection = Data;
	else if (isFullNameOfDwarfSection(Name, "debug_abbrev"))
	DebugAbbrevSection = Data;
	else if (isFullNameOfDwarfSection(Name, "debug_line"))
	DebugLineSection = Data;
	// Don't use debug_aranges for now, as address ranges contained
	// there may not cover all instructions in the module
	// else if (isFullNameOfDwarfSection(Name, "debug_aranges"))
	// DebugArangesSection = Data;
	else if (isFullNameOfDwarfSection(Name, "debug_str"))
	DebugStringSection = Data;
	else if (isFullNameOfDwarfSection(Name, "debug_ranges"))
	DebugRangesSection = Data;
	}
	}

	static ObjectFile *getObjectFile(const std::string &Path) {
	OwningPtr<MemoryBuffer> Buff;
	MemoryBuffer::getFile(Path, Buff);
	return ObjectFile::createObjectFile(Buff.take());
	}

	static std::string getDarwinDWARFResourceForModule(const std::string &Path) {
	StringRef Basename = sys::path::filename(Path);
	const std::string &DSymDirectory = Path + ".dSYM";
	SmallString<16> ResourceName = StringRef(DSymDirectory);
	sys::path::append(ResourceName, "Contents", "Resources", "DWARF");
	sys::path::append(ResourceName, Basename);
	return ResourceName.str();
	}

	static ModuleInfo *getOrCreateModuleInfo(const std::string &ModuleName) {
	ModuleMapIter I = Modules.find(ModuleName);
	if (I != Modules.end())
	return I->second;

	ObjectFile *Obj = getObjectFile(ModuleName);
	if (Obj == 0) {
	// Module name doesn't point to a valid object file.
	Modules.insert(make_pair(ModuleName, (ModuleInfo*)0));
	return 0;
	}

	DIContext *Context = 0;
	bool IsLittleEndian;
	if (getObjectEndianness(Obj, IsLittleEndian)) {
	StringRef DebugInfo;
	StringRef DebugAbbrev;
	StringRef DebugLine;
	StringRef DebugAranges;
	StringRef DebugString;
	StringRef DebugRanges;
	getDebugInfoSections(Obj, DebugInfo, DebugAbbrev, DebugLine,
	DebugAranges, DebugString, DebugRanges);

	// On Darwin we may find DWARF in separate object file in
	// resource directory.
	if (isa<MachOObjectFile>(Obj)) {
	const std::string &ResourceName = getDarwinDWARFResourceForModule(
	ModuleName);
	ObjectFile *ResourceObj = getObjectFile(ResourceName);
	if (ResourceObj != 0)
	getDebugInfoSections(ResourceObj, DebugInfo, DebugAbbrev, DebugLine,
	DebugAranges, DebugString, DebugRanges);
	}

	Context = DIContext::getDWARFContext(
	IsLittleEndian, DebugInfo, DebugAbbrev,
	DebugAranges, DebugLine, DebugString,
	DebugRanges);
	assert(Context);
	}

	ModuleInfo *Info = new ModuleInfo(Obj, Context);
	Modules.insert(make_pair(ModuleName, Info));
	return Info;
	}

	// Assume that __cxa_demangle is provided by libcxxabi.
	extern "C" char __cxa_demangle(const char mangled_name, char *output_buffer,
	size_t length, int status);

	static void printDILineInfo(DILineInfo LineInfo) {
	// By default, DILineInfo contains "<invalid>" for function/filename it
	// cannot fetch. We replace it to "??" to make our output closer to addr2line.
	static const std::string kDILineInfoBadString = "<invalid>";
	static const std::string kSymbolizerBadString = "??";
	if (PrintFunctions) {
	std::string FunctionName = LineInfo.getFunctionName();
	if (FunctionName == kDILineInfoBadString)
	FunctionName = kSymbolizerBadString;
	if (Demangle) {
	int status = 0;
	char *DemangledName = __cxa_demangle(
	FunctionName.c_str(), 0, 0, &status);
	if (status == 0) {
	FunctionName = DemangledName;
	free(DemangledName);
	}
	}
	outs() << FunctionName << "\n";
	}
	std::string Filename = LineInfo.getFileName();
	if (Filename == kDILineInfoBadString)
	Filename = kSymbolizerBadString;
	outs() << Filename <<
	":" << LineInfo.getLine() <<
	":" << LineInfo.getColumn() <<
	"\n";
	}

	static void symbolize(std::string ModuleName, std::string ModuleOffsetStr) {
	ModuleInfo *Info = getOrCreateModuleInfo(ModuleName);
	uint64_t Offset = 0;
	if (Info == 0 \|\|
	StringRef(ModuleOffsetStr).getAsInteger(0, Offset)) {
	printDILineInfo(DILineInfo());
	} else if (PrintInlining) {
	DIInliningInfo InlinedContext = Info->symbolizeInlinedCode(Offset);
	uint32_t FramesNum = InlinedContext.getNumberOfFrames();
	assert(FramesNum > 0);
	for (uint32_t i = 0; i < FramesNum; i++) {
	DILineInfo LineInfo = InlinedContext.getFrame(i);
	printDILineInfo(LineInfo);
	}
	} else {
	DILineInfo LineInfo = Info->symbolizeCode(Offset);
	printDILineInfo(LineInfo);
	}

	outs() << "\n"; // Print extra empty line to mark the end of output.
	outs().flush();
	}

	static bool parseModuleNameAndOffset(std::string &ModuleName,
	std::string &ModuleOffsetStr) {
	static const int kMaxInputStringLength = 1024;
	static const char kDelimiters[] = " \n";
	char InputString[kMaxInputStringLength];
	if (!fgets(InputString, sizeof(InputString), stdin))
	return false;
	ModuleName = "";
	ModuleOffsetStr = "";
	// FIXME: Handle case when filename is given in quotes.
	if (char *FilePath = strtok(InputString, kDelimiters)) {
	ModuleName = FilePath;
	if (char OffsetStr = strtok((char)0, kDelimiters))
	ModuleOffsetStr = OffsetStr;
	}
	return true;
	}

	int main(int argc, char **argv) {
	// Print 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, "llvm symbolizer for compiler-rt\n");
	ToolInvocationPath = argv[0];

	std::string ModuleName;
	std::string ModuleOffsetStr;
	while (parseModuleNameAndOffset(ModuleName, ModuleOffsetStr)) {
	symbolize(ModuleName, ModuleOffsetStr);
	}
	return 0;
	}