//===-- gsymutil.cpp - GSYM dumping and creation utility for llvm ---------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/ADT/Triple.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/MachOUniversal.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Regex.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstring>
#include <inttypes.h>
#include <iostream>
#include <map>
#include <string>
#include <system_error>
#include <vector>

#include "llvm/DebugInfo/GSYM/DwarfTransformer.h"
#include "llvm/DebugInfo/GSYM/FunctionInfo.h"
#include "llvm/DebugInfo/GSYM/GsymCreator.h"
#include "llvm/DebugInfo/GSYM/GsymReader.h"
#include "llvm/DebugInfo/GSYM/InlineInfo.h"
#include "llvm/DebugInfo/GSYM/LookupResult.h"
#include "llvm/DebugInfo/GSYM/ObjectFileTransformer.h"
#include <optional>

using namespace llvm;
using namespace gsym;
using namespace object;

/// @}
/// Command line options.
/// @{

namespace {
using namespace cl;

OptionCategory GeneralOptions("Options");
OptionCategory ConversionOptions("Conversion Options");
OptionCategory LookupOptions("Lookup Options");

static opt<bool> Help("h", desc("Alias for -help"), Hidden,
                      cat(GeneralOptions));

static opt<bool> Verbose("verbose",
                         desc("Enable verbose logging and encoding details."),
                         cat(GeneralOptions));

static list<std::string> InputFilenames(Positional, desc("<input GSYM files>"),
                                        cat(GeneralOptions));

static opt<std::string>
    ConvertFilename("convert", cl::init(""),
                    cl::desc("Convert the specified file to the GSYM format.\n"
                             "Supported files include ELF and mach-o files "
                             "that will have their debug info (DWARF) and "
                             "symbol table converted."),
                    cl::value_desc("path"), cat(ConversionOptions));

static list<std::string>
    ArchFilters("arch",
                desc("Process debug information for the specified CPU "
                     "architecture only.\nArchitectures may be specified by "
                     "name or by number.\nThis option can be specified "
                     "multiple times, once for each desired architecture."),
                cl::value_desc("arch"), cat(ConversionOptions));

static opt<std::string>
    OutputFilename("out-file", cl::init(""),
                   cl::desc("Specify the path where the converted GSYM file "
                            "will be saved.\nWhen not specified, a '.gsym' "
                            "extension will be appended to the file name "
                            "specified in the --convert option."),
                   cl::value_desc("path"), cat(ConversionOptions));
static alias OutputFilenameAlias("o", desc("Alias for -out-file."),
                                 aliasopt(OutputFilename),
                                 cat(ConversionOptions));

static opt<bool> Verify("verify",
                        desc("Verify the generated GSYM file against the "
                             "information in the file that was converted."),
                        cat(ConversionOptions));

static opt<unsigned>
    NumThreads("num-threads",
               desc("Specify the maximum number (n) of simultaneous threads "
                    "to use when converting files to GSYM.\nDefaults to the "
                    "number of cores on the current machine."),
               cl::value_desc("n"), cat(ConversionOptions));

static opt<bool>
    Quiet("quiet", desc("Do not output warnings about the debug information"),
          cat(ConversionOptions));

static list<uint64_t> LookupAddresses("address",
                                      desc("Lookup an address in a GSYM file"),
                                      cl::value_desc("addr"),
                                      cat(LookupOptions));

static opt<bool> LookupAddressesFromStdin(
    "addresses-from-stdin",
    desc("Lookup addresses in a GSYM file that are read from stdin\nEach input "
         "line is expected to be of the following format: <addr> <gsym-path>"),
    cat(LookupOptions));

} // namespace
/// @}
//===----------------------------------------------------------------------===//

static void error(Error Err) {
  if (!Err)
    return;
  WithColor::error() << toString(std::move(Err)) << "\n";
  exit(1);
}

static void error(StringRef Prefix, llvm::Error Err) {
  if (!Err)
    return;
  errs() << Prefix << ": " << Err << "\n";
  consumeError(std::move(Err));
  exit(1);
}

static void error(StringRef Prefix, std::error_code EC) {
  if (!EC)
    return;
  errs() << Prefix << ": " << EC.message() << "\n";
  exit(1);
}

static uint32_t getCPUType(MachOObjectFile &MachO) {
  if (MachO.is64Bit())
    return MachO.getHeader64().cputype;
  else
    return MachO.getHeader().cputype;
}

/// Return true if the object file has not been filtered by an --arch option.
static bool filterArch(MachOObjectFile &Obj) {
  if (ArchFilters.empty())
    return true;

  Triple ObjTriple(Obj.getArchTriple());
  StringRef ObjArch = ObjTriple.getArchName();

  for (auto Arch : ArchFilters) {
    // Match name.
    if (Arch == ObjArch)
      return true;

    // Match architecture number.
    unsigned Value;
    if (!StringRef(Arch).getAsInteger(0, Value))
      if (Value == getCPUType(Obj))
        return true;
  }
  return false;
}

/// Determine the virtual address that is considered the base address of an ELF
/// object file.
///
/// The base address of an ELF file is the the "p_vaddr" of the first program
/// header whose "p_type" is PT_LOAD.
///
/// \param ELFFile An ELF object file we will search.
///
/// \returns A valid image base address if we are able to extract one.
template <class ELFT>
static std::optional<uint64_t>
getImageBaseAddress(const object::ELFFile<ELFT> &ELFFile) {
  auto PhdrRangeOrErr = ELFFile.program_headers();
  if (!PhdrRangeOrErr) {
    consumeError(PhdrRangeOrErr.takeError());
    return std::nullopt;
  }
  for (const typename ELFT::Phdr &Phdr : *PhdrRangeOrErr)
    if (Phdr.p_type == ELF::PT_LOAD)
      return (uint64_t)Phdr.p_vaddr;
  return std::nullopt;
}

/// Determine the virtual address that is considered the base address of mach-o
/// object file.
///
/// The base address of a mach-o file is the vmaddr of the  "__TEXT" segment.
///
/// \param MachO A mach-o object file we will search.
///
/// \returns A valid image base address if we are able to extract one.
static std::optional<uint64_t>
getImageBaseAddress(const object::MachOObjectFile *MachO) {
  for (const auto &Command : MachO->load_commands()) {
    if (Command.C.cmd == MachO::LC_SEGMENT) {
      MachO::segment_command SLC = MachO->getSegmentLoadCommand(Command);
      StringRef SegName = SLC.segname;
      if (SegName == "__TEXT")
        return SLC.vmaddr;
    } else if (Command.C.cmd == MachO::LC_SEGMENT_64) {
      MachO::segment_command_64 SLC = MachO->getSegment64LoadCommand(Command);
      StringRef SegName = SLC.segname;
      if (SegName == "__TEXT")
        return SLC.vmaddr;
    }
  }
  return std::nullopt;
}

/// Determine the virtual address that is considered the base address of an
/// object file.
///
/// Since GSYM files are used for symbolication, many clients will need to
/// easily adjust addresses they find in stack traces so the lookups happen
/// on unslid addresses from the original object file. If the base address of
/// a GSYM file is set to the base address of the image, then this address
/// adjusting is much easier.
///
/// \param Obj An object file we will search.
///
/// \returns A valid image base address if we are able to extract one.
static std::optional<uint64_t> getImageBaseAddress(object::ObjectFile &Obj) {
  if (const auto *MachO = dyn_cast<object::MachOObjectFile>(&Obj))
    return getImageBaseAddress(MachO);
  else if (const auto *ELFObj = dyn_cast<object::ELF32LEObjectFile>(&Obj))
    return getImageBaseAddress(ELFObj->getELFFile());
  else if (const auto *ELFObj = dyn_cast<object::ELF32BEObjectFile>(&Obj))
    return getImageBaseAddress(ELFObj->getELFFile());
  else if (const auto *ELFObj = dyn_cast<object::ELF64LEObjectFile>(&Obj))
    return getImageBaseAddress(ELFObj->getELFFile());
  else if (const auto *ELFObj = dyn_cast<object::ELF64BEObjectFile>(&Obj))
    return getImageBaseAddress(ELFObj->getELFFile());
  return std::nullopt;
}

static llvm::Error handleObjectFile(ObjectFile &Obj,
                                    const std::string &OutFile) {
  auto ThreadCount =
      NumThreads > 0 ? NumThreads : std::thread::hardware_concurrency();
  auto &OS = outs();

  GsymCreator Gsym(Quiet);

  // See if we can figure out the base address for a given object file, and if
  // we can, then set the base address to use to this value. This will ease
  // symbolication since clients can slide the GSYM lookup addresses by using
  // the load bias of the shared library.
  if (auto ImageBaseAddr = getImageBaseAddress(Obj))
    Gsym.setBaseAddress(*ImageBaseAddr);

  // We need to know where the valid sections are that contain instructions.
  // See header documentation for DWARFTransformer::SetValidTextRanges() for
  // defails.
  AddressRanges TextRanges;
  for (const object::SectionRef &Sect : Obj.sections()) {
    if (!Sect.isText())
      continue;
    const uint64_t Size = Sect.getSize();
    if (Size == 0)
      continue;
    const uint64_t StartAddr = Sect.getAddress();
    TextRanges.insert(AddressRange(StartAddr, StartAddr + Size));
  }

  // Make sure there is DWARF to convert first.
  std::unique_ptr<DWARFContext> DICtx = DWARFContext::create(Obj);
  if (!DICtx)
    return createStringError(std::errc::invalid_argument,
                             "unable to create DWARF context");

  // Make a DWARF transformer object and populate the ranges of the code
  // so we don't end up adding invalid functions to GSYM data.
  DwarfTransformer DT(*DICtx, OS, Gsym);
  if (!TextRanges.empty())
    Gsym.SetValidTextRanges(TextRanges);

  // Convert all DWARF to GSYM.
  if (auto Err = DT.convert(ThreadCount))
    return Err;

  // Get the UUID and convert symbol table to GSYM.
  if (auto Err = ObjectFileTransformer::convert(Obj, OS, Gsym))
    return Err;

  // Finalize the GSYM to make it ready to save to disk. This will remove
  // duplicate FunctionInfo entries where we might have found an entry from
  // debug info and also a symbol table entry from the object file.
  if (auto Err = Gsym.finalize(OS))
    return Err;

  // Save the GSYM file to disk.
  support::endianness Endian =
      Obj.makeTriple().isLittleEndian() ? support::little : support::big;
  if (auto Err = Gsym.save(OutFile, Endian))
    return Err;

  // Verify the DWARF if requested. This will ensure all the info in the DWARF
  // can be looked up in the GSYM and that all lookups get matching data.
  if (Verify) {
    if (auto Err = DT.verify(OutFile))
      return Err;
  }

  return Error::success();
}

static llvm::Error handleBuffer(StringRef Filename, MemoryBufferRef Buffer,
                                const std::string &OutFile) {
  Expected<std::unique_ptr<Binary>> BinOrErr = object::createBinary(Buffer);
  error(Filename, errorToErrorCode(BinOrErr.takeError()));

  if (auto *Obj = dyn_cast<ObjectFile>(BinOrErr->get())) {
    Triple ObjTriple(Obj->makeTriple());
    auto ArchName = ObjTriple.getArchName();
    outs() << "Output file (" << ArchName << "): " << OutFile << "\n";
    if (auto Err = handleObjectFile(*Obj, OutFile))
      return Err;
  } else if (auto *Fat = dyn_cast<MachOUniversalBinary>(BinOrErr->get())) {
    // Iterate over all contained architectures and filter out any that were
    // not specified with the "--arch <arch>" option. If the --arch option was
    // not specified on the command line, we will process all architectures.
    std::vector<std::unique_ptr<MachOObjectFile>> FilterObjs;
    for (auto &ObjForArch : Fat->objects()) {
      if (auto MachOOrErr = ObjForArch.getAsObjectFile()) {
        auto &Obj = **MachOOrErr;
        if (filterArch(Obj))
          FilterObjs.emplace_back(MachOOrErr->release());
      } else {
        error(Filename, MachOOrErr.takeError());
      }
    }
    if (FilterObjs.empty())
      error(Filename, createStringError(std::errc::invalid_argument,
                                        "no matching architectures found"));

    // Now handle each architecture we need to convert.
    for (auto &Obj : FilterObjs) {
      Triple ObjTriple(Obj->getArchTriple());
      auto ArchName = ObjTriple.getArchName();
      std::string ArchOutFile(OutFile);
      // If we are only handling a single architecture, then we will use the
      // normal output file. If we are handling multiple architectures append
      // the architecture name to the end of the out file path so that we
      // don't overwrite the previous architecture's gsym file.
      if (FilterObjs.size() > 1) {
        ArchOutFile.append(1, '.');
        ArchOutFile.append(ArchName.str());
      }
      outs() << "Output file (" << ArchName << "): " << ArchOutFile << "\n";
      if (auto Err = handleObjectFile(*Obj, ArchOutFile))
        return Err;
    }
  }
  return Error::success();
}

static llvm::Error handleFileConversionToGSYM(StringRef Filename,
                                              const std::string &OutFile) {
  ErrorOr<std::unique_ptr<MemoryBuffer>> BuffOrErr =
      MemoryBuffer::getFileOrSTDIN(Filename);
  error(Filename, BuffOrErr.getError());
  std::unique_ptr<MemoryBuffer> Buffer = std::move(BuffOrErr.get());
  return handleBuffer(Filename, *Buffer, OutFile);
}

static llvm::Error convertFileToGSYM(raw_ostream &OS) {
  // Expand any .dSYM bundles to the individual object files contained therein.
  std::vector<std::string> Objects;
  std::string OutFile = OutputFilename;
  if (OutFile.empty()) {
    OutFile = ConvertFilename;
    OutFile += ".gsym";
  }

  OS << "Input file: " << ConvertFilename << "\n";

  if (auto DsymObjectsOrErr =
          MachOObjectFile::findDsymObjectMembers(ConvertFilename)) {
    if (DsymObjectsOrErr->empty())
      Objects.push_back(ConvertFilename);
    else
      llvm::append_range(Objects, *DsymObjectsOrErr);
  } else {
    error(DsymObjectsOrErr.takeError());
  }

  for (auto Object : Objects) {
    if (auto Err = handleFileConversionToGSYM(Object, OutFile))
      return Err;
  }
  return Error::success();
}

static void doLookup(GsymReader &Gsym, uint64_t Addr, raw_ostream &OS) {
  if (auto Result = Gsym.lookup(Addr)) {
    // If verbose is enabled dump the full function info for the address.
    if (Verbose) {
      if (auto FI = Gsym.getFunctionInfo(Addr)) {
        OS << "FunctionInfo for " << HEX64(Addr) << ":\n";
        Gsym.dump(OS, *FI);
        OS << "\nLookupResult for " << HEX64(Addr) << ":\n";
      }
    }
    OS << Result.get();
  } else {
    if (Verbose)
      OS << "\nLookupResult for " << HEX64(Addr) << ":\n";
    OS << HEX64(Addr) << ": ";
    logAllUnhandledErrors(Result.takeError(), OS, "error: ");
  }
  if (Verbose)
    OS << "\n";
}

int main(int argc, char const *argv[]) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal(argv[0]);
  PrettyStackTraceProgram X(argc, argv);
  llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.

  llvm::InitializeAllTargets();

  const char *Overview =
      "A tool for dumping, searching and creating GSYM files.\n\n"
      "Specify one or more GSYM paths as arguments to dump all of the "
      "information in each GSYM file.\n"
      "Specify a single GSYM file along with one or more --lookup options to "
      "lookup addresses within that GSYM file.\n"
      "Use the --convert option to specify a file with option --out-file "
      "option to convert to GSYM format.\n";
  HideUnrelatedOptions({&GeneralOptions, &ConversionOptions, &LookupOptions});
  cl::ParseCommandLineOptions(argc, argv, Overview);

  if (Help) {
    PrintHelpMessage(/*Hidden =*/false, /*Categorized =*/true);
    return 0;
  }

  raw_ostream &OS = outs();

  if (!ConvertFilename.empty()) {
    // Convert DWARF to GSYM
    if (!InputFilenames.empty()) {
      OS << "error: no input files can be specified when using the --convert "
            "option.\n";
      return 1;
    }
    // Call error() if we have an error and it will exit with a status of 1
    if (auto Err = convertFileToGSYM(OS))
      error("DWARF conversion failed: ", std::move(Err));
    return 0;
  }

  if (LookupAddressesFromStdin) {
    if (!LookupAddresses.empty() || !InputFilenames.empty()) {
      OS << "error: no input files or addresses can be specified when using "
            "the --addresses-from-stdin "
            "option.\n";
      return 1;
    }

    std::string InputLine;
    std::string CurrentGSYMPath;
    std::optional<Expected<GsymReader>> CurrentGsym;

    while (std::getline(std::cin, InputLine)) {
      // Strip newline characters.
      std::string StrippedInputLine(InputLine);
      llvm::erase_if(StrippedInputLine,
                     [](char c) { return c == '\r' || c == '\n'; });

      StringRef AddrStr, GSYMPath;
      std::tie(AddrStr, GSYMPath) =
          llvm::StringRef{StrippedInputLine}.split(' ');

      if (GSYMPath != CurrentGSYMPath) {
        CurrentGsym = GsymReader::openFile(GSYMPath);
        if (!*CurrentGsym)
          error(GSYMPath, CurrentGsym->takeError());
        CurrentGSYMPath = GSYMPath;
      }

      uint64_t Addr;
      if (AddrStr.getAsInteger(0, Addr)) {
        OS << "error: invalid address " << AddrStr
           << ", expected: Address GsymFile.\n";
        return 1;
      }

      doLookup(**CurrentGsym, Addr, OS);

      OS << "\n";
      OS.flush();
    }

    return EXIT_SUCCESS;
  }

  // Dump or access data inside GSYM files
  for (const auto &GSYMPath : InputFilenames) {
    auto Gsym = GsymReader::openFile(GSYMPath);
    if (!Gsym)
      error(GSYMPath, Gsym.takeError());

    if (LookupAddresses.empty()) {
      Gsym->dump(outs());
      continue;
    }

    // Lookup an address in a GSYM file and print any matches.
    OS << "Looking up addresses in \"" << GSYMPath << "\":\n";
    for (auto Addr : LookupAddresses) {
      doLookup(*Gsym, Addr, OS);
    }
  }
  return EXIT_SUCCESS;
}