llvm-6502/tools/llvm-symbolizer/LLVMSymbolize.cpp
Rafael Espindola 548f2b6e8f Don't own the buffer in object::Binary.
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.

Keeping this ownership would make supporting IR inside native objects
particularly painful.

This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.

This patch introduces a few new types.

* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
  This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
  for convenience functions that take a filename and return both the
  buffer and the Binary using that buffer.

The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216002 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 18:44:46 +00:00

446 lines
15 KiB
C++

//===-- LLVMSymbolize.cpp -------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implementation for LLVM symbolization library.
//
//===----------------------------------------------------------------------===//
#include "LLVMSymbolize.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Config/config.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/MachO.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include <sstream>
#include <stdlib.h>
namespace llvm {
namespace symbolize {
static bool error(std::error_code ec) {
if (!ec)
return false;
errs() << "LLVMSymbolizer: error reading file: " << ec.message() << ".\n";
return true;
}
static DILineInfoSpecifier
getDILineInfoSpecifier(const LLVMSymbolizer::Options &Opts) {
return DILineInfoSpecifier(
DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
Opts.PrintFunctions);
}
ModuleInfo::ModuleInfo(ObjectFile *Obj, DIContext *DICtx)
: Module(Obj), DebugInfoContext(DICtx) {
for (const SymbolRef &Symbol : Module->symbols()) {
addSymbol(Symbol);
}
bool NoSymbolTable = (Module->symbol_begin() == Module->symbol_end());
if (NoSymbolTable && Module->isELF()) {
// Fallback to dynamic symbol table, if regular symbol table is stripped.
std::pair<symbol_iterator, symbol_iterator> IDyn =
getELFDynamicSymbolIterators(Module);
for (symbol_iterator si = IDyn.first, se = IDyn.second; si != se; ++si) {
addSymbol(*si);
}
}
}
void ModuleInfo::addSymbol(const SymbolRef &Symbol) {
SymbolRef::Type SymbolType;
if (error(Symbol.getType(SymbolType)))
return;
if (SymbolType != SymbolRef::ST_Function && SymbolType != SymbolRef::ST_Data)
return;
uint64_t SymbolAddress;
if (error(Symbol.getAddress(SymbolAddress)) ||
SymbolAddress == UnknownAddressOrSize)
return;
uint64_t SymbolSize;
// Getting symbol size is linear for Mach-O files, so assume that symbol
// occupies the memory range up to the following symbol.
if (isa<MachOObjectFile>(Module))
SymbolSize = 0;
else if (error(Symbol.getSize(SymbolSize)) ||
SymbolSize == UnknownAddressOrSize)
return;
StringRef SymbolName;
if (error(Symbol.getName(SymbolName)))
return;
// Mach-O symbol table names have leading underscore, skip it.
if (Module->isMachO() && SymbolName.size() > 0 && SymbolName[0] == '_')
SymbolName = SymbolName.drop_front();
// FIXME: If a function has alias, there are two entries in symbol table
// with same address size. Make sure we choose the correct one.
SymbolMapTy &M = SymbolType == SymbolRef::ST_Function ? Functions : Objects;
SymbolDesc SD = { SymbolAddress, SymbolSize };
M.insert(std::make_pair(SD, SymbolName));
}
bool ModuleInfo::getNameFromSymbolTable(SymbolRef::Type Type, uint64_t Address,
std::string &Name, uint64_t &Addr,
uint64_t &Size) const {
const SymbolMapTy &M = Type == SymbolRef::ST_Function ? Functions : Objects;
if (M.empty())
return false;
SymbolDesc SD = { Address, Address };
SymbolMapTy::const_iterator it = M.upper_bound(SD);
if (it == M.begin())
return false;
--it;
if (it->first.Size != 0 && it->first.Addr + it->first.Size <= Address)
return false;
Name = it->second.str();
Addr = it->first.Addr;
Size = it->first.Size;
return true;
}
DILineInfo ModuleInfo::symbolizeCode(
uint64_t ModuleOffset, const LLVMSymbolizer::Options &Opts) const {
DILineInfo LineInfo;
if (DebugInfoContext) {
LineInfo = DebugInfoContext->getLineInfoForAddress(
ModuleOffset, getDILineInfoSpecifier(Opts));
}
// Override function name from symbol table if necessary.
if (Opts.PrintFunctions != FunctionNameKind::None && Opts.UseSymbolTable) {
std::string FunctionName;
uint64_t Start, Size;
if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
FunctionName, Start, Size)) {
LineInfo.FunctionName = FunctionName;
}
}
return LineInfo;
}
DIInliningInfo ModuleInfo::symbolizeInlinedCode(
uint64_t ModuleOffset, const LLVMSymbolizer::Options &Opts) const {
DIInliningInfo InlinedContext;
if (DebugInfoContext) {
InlinedContext = DebugInfoContext->getInliningInfoForAddress(
ModuleOffset, getDILineInfoSpecifier(Opts));
}
// 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 (Opts.PrintFunctions != FunctionNameKind::None && Opts.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 FunctionName;
uint64_t Start, Size;
if (getNameFromSymbolTable(SymbolRef::ST_Function, ModuleOffset,
FunctionName, Start, Size)) {
LineInfo.FunctionName = FunctionName;
}
}
PatchedInlinedContext.addFrame(LineInfo);
}
InlinedContext = PatchedInlinedContext;
}
return InlinedContext;
}
bool ModuleInfo::symbolizeData(uint64_t ModuleOffset, std::string &Name,
uint64_t &Start, uint64_t &Size) const {
return getNameFromSymbolTable(SymbolRef::ST_Data, ModuleOffset, Name, Start,
Size);
}
const char LLVMSymbolizer::kBadString[] = "??";
std::string LLVMSymbolizer::symbolizeCode(const std::string &ModuleName,
uint64_t ModuleOffset) {
ModuleInfo *Info = getOrCreateModuleInfo(ModuleName);
if (!Info)
return printDILineInfo(DILineInfo());
if (Opts.PrintInlining) {
DIInliningInfo InlinedContext =
Info->symbolizeInlinedCode(ModuleOffset, Opts);
uint32_t FramesNum = InlinedContext.getNumberOfFrames();
assert(FramesNum > 0);
std::string Result;
for (uint32_t i = 0; i < FramesNum; i++) {
DILineInfo LineInfo = InlinedContext.getFrame(i);
Result += printDILineInfo(LineInfo);
}
return Result;
}
DILineInfo LineInfo = Info->symbolizeCode(ModuleOffset, Opts);
return printDILineInfo(LineInfo);
}
std::string LLVMSymbolizer::symbolizeData(const std::string &ModuleName,
uint64_t ModuleOffset) {
std::string Name = kBadString;
uint64_t Start = 0;
uint64_t Size = 0;
if (Opts.UseSymbolTable) {
if (ModuleInfo *Info = getOrCreateModuleInfo(ModuleName)) {
if (Info->symbolizeData(ModuleOffset, Name, Start, Size) && Opts.Demangle)
Name = DemangleName(Name);
}
}
std::stringstream ss;
ss << Name << "\n" << Start << " " << Size << "\n";
return ss.str();
}
void LLVMSymbolizer::flush() {
DeleteContainerSeconds(Modules);
BinaryForPath.clear();
ObjectFileForArch.clear();
}
static std::string getDarwinDWARFResourceForPath(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 bool checkFileCRC(StringRef Path, uint32_t CRCHash) {
ErrorOr<std::unique_ptr<MemoryBuffer>> MB =
MemoryBuffer::getFileOrSTDIN(Path);
if (!MB)
return false;
return !zlib::isAvailable() || CRCHash == zlib::crc32(MB.get()->getBuffer());
}
static bool findDebugBinary(const std::string &OrigPath,
const std::string &DebuglinkName, uint32_t CRCHash,
std::string &Result) {
std::string OrigRealPath = OrigPath;
#if defined(HAVE_REALPATH)
if (char *RP = realpath(OrigPath.c_str(), nullptr)) {
OrigRealPath = RP;
free(RP);
}
#endif
SmallString<16> OrigDir(OrigRealPath);
llvm::sys::path::remove_filename(OrigDir);
SmallString<16> DebugPath = OrigDir;
// Try /path/to/original_binary/debuglink_name
llvm::sys::path::append(DebugPath, DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
Result = DebugPath.str();
return true;
}
// Try /path/to/original_binary/.debug/debuglink_name
DebugPath = OrigRealPath;
llvm::sys::path::append(DebugPath, ".debug", DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
Result = DebugPath.str();
return true;
}
// Try /usr/lib/debug/path/to/original_binary/debuglink_name
DebugPath = "/usr/lib/debug";
llvm::sys::path::append(DebugPath, llvm::sys::path::relative_path(OrigDir),
DebuglinkName);
if (checkFileCRC(DebugPath, CRCHash)) {
Result = DebugPath.str();
return true;
}
return false;
}
static bool getGNUDebuglinkContents(const Binary *Bin, std::string &DebugName,
uint32_t &CRCHash) {
const ObjectFile *Obj = dyn_cast<ObjectFile>(Bin);
if (!Obj)
return false;
for (const SectionRef &Section : Obj->sections()) {
StringRef Name;
Section.getName(Name);
Name = Name.substr(Name.find_first_not_of("._"));
if (Name == "gnu_debuglink") {
StringRef Data;
Section.getContents(Data);
DataExtractor DE(Data, Obj->isLittleEndian(), 0);
uint32_t Offset = 0;
if (const char *DebugNameStr = DE.getCStr(&Offset)) {
// 4-byte align the offset.
Offset = (Offset + 3) & ~0x3;
if (DE.isValidOffsetForDataOfSize(Offset, 4)) {
DebugName = DebugNameStr;
CRCHash = DE.getU32(&Offset);
return true;
}
}
break;
}
}
return false;
}
LLVMSymbolizer::BinaryPair
LLVMSymbolizer::getOrCreateBinary(const std::string &Path) {
BinaryMapTy::iterator I = BinaryForPath.find(Path);
if (I != BinaryForPath.end())
return I->second;
Binary *Bin = nullptr;
Binary *DbgBin = nullptr;
ErrorOr<OwningBinary<Binary>> BinaryOrErr = createBinary(Path);
if (!error(BinaryOrErr.getError())) {
OwningBinary<Binary> &ParsedBinary = BinaryOrErr.get();
// Check if it's a universal binary.
Bin = ParsedBinary.getBinary().get();
addOwningBinary(std::move(ParsedBinary));
if (Bin->isMachO() || Bin->isMachOUniversalBinary()) {
// On Darwin we may find DWARF in separate object file in
// resource directory.
const std::string &ResourcePath =
getDarwinDWARFResourceForPath(Path);
BinaryOrErr = createBinary(ResourcePath);
std::error_code EC = BinaryOrErr.getError();
if (EC != errc::no_such_file_or_directory && !error(EC)) {
OwningBinary<Binary> B = std::move(BinaryOrErr.get());
DbgBin = B.getBinary().get();
addOwningBinary(std::move(B));
}
}
// Try to locate the debug binary using .gnu_debuglink section.
if (!DbgBin) {
std::string DebuglinkName;
uint32_t CRCHash;
std::string DebugBinaryPath;
if (getGNUDebuglinkContents(Bin, DebuglinkName, CRCHash) &&
findDebugBinary(Path, DebuglinkName, CRCHash, DebugBinaryPath)) {
BinaryOrErr = createBinary(DebugBinaryPath);
if (!error(BinaryOrErr.getError())) {
OwningBinary<Binary> B = std::move(BinaryOrErr.get());
DbgBin = B.getBinary().get();
addOwningBinary(std::move(B));
}
}
}
}
if (!DbgBin)
DbgBin = Bin;
BinaryPair Res = std::make_pair(Bin, DbgBin);
BinaryForPath[Path] = Res;
return Res;
}
ObjectFile *
LLVMSymbolizer::getObjectFileFromBinary(Binary *Bin, const std::string &ArchName) {
if (!Bin)
return nullptr;
ObjectFile *Res = nullptr;
if (MachOUniversalBinary *UB = dyn_cast<MachOUniversalBinary>(Bin)) {
ObjectFileForArchMapTy::iterator I = ObjectFileForArch.find(
std::make_pair(UB, ArchName));
if (I != ObjectFileForArch.end())
return I->second;
ErrorOr<std::unique_ptr<ObjectFile>> ParsedObj =
UB->getObjectForArch(Triple(ArchName).getArch());
if (ParsedObj) {
Res = ParsedObj.get().get();
ParsedBinariesAndObjects.push_back(std::move(ParsedObj.get()));
}
ObjectFileForArch[std::make_pair(UB, ArchName)] = Res;
} else if (Bin->isObject()) {
Res = cast<ObjectFile>(Bin);
}
return Res;
}
ModuleInfo *
LLVMSymbolizer::getOrCreateModuleInfo(const std::string &ModuleName) {
ModuleMapTy::iterator I = Modules.find(ModuleName);
if (I != Modules.end())
return I->second;
std::string BinaryName = ModuleName;
std::string ArchName = Opts.DefaultArch;
size_t ColonPos = ModuleName.find_last_of(':');
// Verify that substring after colon form a valid arch name.
if (ColonPos != std::string::npos) {
std::string ArchStr = ModuleName.substr(ColonPos + 1);
if (Triple(ArchStr).getArch() != Triple::UnknownArch) {
BinaryName = ModuleName.substr(0, ColonPos);
ArchName = ArchStr;
}
}
BinaryPair Binaries = getOrCreateBinary(BinaryName);
ObjectFile *Obj = getObjectFileFromBinary(Binaries.first, ArchName);
ObjectFile *DbgObj = getObjectFileFromBinary(Binaries.second, ArchName);
if (!Obj) {
// Failed to find valid object file.
Modules.insert(make_pair(ModuleName, (ModuleInfo *)nullptr));
return nullptr;
}
DIContext *Context = DIContext::getDWARFContext(*DbgObj);
assert(Context);
ModuleInfo *Info = new ModuleInfo(Obj, Context);
Modules.insert(make_pair(ModuleName, Info));
return Info;
}
std::string LLVMSymbolizer::printDILineInfo(DILineInfo LineInfo) const {
// 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>";
std::stringstream Result;
if (Opts.PrintFunctions != FunctionNameKind::None) {
std::string FunctionName = LineInfo.FunctionName;
if (FunctionName == kDILineInfoBadString)
FunctionName = kBadString;
else if (Opts.Demangle)
FunctionName = DemangleName(FunctionName);
Result << FunctionName << "\n";
}
std::string Filename = LineInfo.FileName;
if (Filename == kDILineInfoBadString)
Filename = kBadString;
Result << Filename << ":" << LineInfo.Line << ":" << LineInfo.Column << "\n";
return Result.str();
}
#if !defined(_MSC_VER)
// Assume that __cxa_demangle is provided by libcxxabi (except for Windows).
extern "C" char *__cxa_demangle(const char *mangled_name, char *output_buffer,
size_t *length, int *status);
#endif
std::string LLVMSymbolizer::DemangleName(const std::string &Name) {
#if !defined(_MSC_VER)
// We can spoil names of symbols with C linkage, so use an heuristic
// approach to check if the name should be demangled.
if (Name.substr(0, 2) != "_Z")
return Name;
int status = 0;
char *DemangledName = __cxa_demangle(Name.c_str(), nullptr, nullptr, &status);
if (status != 0)
return Name;
std::string Result = DemangledName;
free(DemangledName);
return Result;
#else
return Name;
#endif
}
} // namespace symbolize
} // namespace llvm