llvm-project/bolt/tools/bat-dump/bat-dump.cpp

//===- bolt/tools/bat-dump/bat-dump.cpp - BAT dumper utility --------------===//
//
// 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 "bolt/Profile/BoltAddressTranslation.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/raw_ostream.h"
#include <assert.h>
#include <cstdint>
#include <map>
#include <stdlib.h>
#include <string>
#include <system_error>
#include <type_traits>
#include <utility>

using namespace llvm;
using namespace bolt;

namespace opts {

static cl::OptionCategory BatDumpCategory("BAT dump options");

static cl::OptionCategory *BatDumpCategories[] = {&BatDumpCategory};

static cl::opt<std::string> InputFilename(cl::Positional,
                                          cl::desc("<executable>"),
                                          cl::Required,
                                          cl::cat(BatDumpCategory));

static cl::list<uint64_t> Translate("translate",
                                    cl::desc("translate addresses using BAT"),
                                    cl::value_desc("addr"),
                                    cl::cat(BatDumpCategory));

static cl::opt<bool> DumpAll("dump-all", cl::desc("dump all BAT tables"),
                             cl::cat(BatDumpCategory));

} // namespace opts

static StringRef ToolName;

static void report_error(StringRef Message, std::error_code EC) {
  assert(EC);
  errs() << ToolName << ": '" << Message << "': " << EC.message() << ".\n";
  exit(1);
}

static void report_error(StringRef Message, Error E) {
  assert(E);
  errs() << ToolName << ": '" << Message << "': " << toString(std::move(E))
         << ".\n";
  exit(1);
}

static std::string GetExecutablePath(const char *Argv0) {
  SmallString<256> ExecutablePath(Argv0);
  // Do a PATH lookup if Argv0 isn't a valid path.
  if (!llvm::sys::fs::exists(ExecutablePath))
    if (llvm::ErrorOr<std::string> P =
            llvm::sys::findProgramByName(ExecutablePath))
      ExecutablePath = *P;
  return std::string(ExecutablePath);
}

void dumpBATFor(llvm::object::ELFObjectFileBase *InputFile) {
  BoltAddressTranslation BAT;
  if (!BAT.enabledFor(InputFile)) {
    errs() << "error: no BAT table found.\n";
    exit(1);
  }

  // Look for BAT section
  bool Found = false;
  StringRef SectionContents;
  for (const llvm::object::SectionRef &Section : InputFile->sections()) {
    Expected<StringRef> SectionNameOrErr = Section.getName();
    if (Error E = SectionNameOrErr.takeError())
      continue;

    if (SectionNameOrErr.get() != BoltAddressTranslation::SECTION_NAME)
      continue;

    Found = true;
    Expected<StringRef> ContentsOrErr = Section.getContents();
    if (Error E = ContentsOrErr.takeError())
      continue;
    SectionContents = ContentsOrErr.get();
  }

  if (!Found) {
    errs() << "BOLT-ERROR: failed to parse BOLT address translation "
              "table. No BAT section found\n";
    exit(1);
  }

  if (std::error_code EC = BAT.parse(outs(), SectionContents)) {
    errs() << "BOLT-ERROR: failed to parse BOLT address translation "
              "table. Malformed BAT section\n";
    exit(1);
  }

  if (opts::DumpAll)
    BAT.dump(outs());

  if (!opts::Translate.empty()) {
    // Build map of <Address, SymbolName> for InputFile
    std::map<uint64_t, StringRef> FunctionsMap;
    for (const llvm::object::ELFSymbolRef &Symbol : InputFile->symbols()) {
      Expected<StringRef> NameOrError = Symbol.getName();
      if (NameOrError.takeError())
        continue;
      if (cantFail(Symbol.getType()) != llvm::object::SymbolRef::ST_Function)
        continue;
      const StringRef Name = *NameOrError;
      const uint64_t Address = cantFail(Symbol.getAddress());
      FunctionsMap[Address] = Name;
    }

    outs() << "Translating addresses according to parsed BAT tables:\n";
    for (uint64_t Address : opts::Translate) {
      auto FI = FunctionsMap.upper_bound(Address);
      if (FI == FunctionsMap.begin()) {
        outs() << "No function symbol found for 0x" << Twine::utohexstr(Address)
               << "\n";
        continue;
      }
      --FI;
      outs() << "0x" << Twine::utohexstr(Address) << " -> " << FI->second
             << " + 0x"
             << Twine::utohexstr(
                    BAT.translate(FI->first, Address - FI->first, false))
             << "\n";
    }
  }
}

int main(int argc, char **argv) {
  cl::HideUnrelatedOptions(ArrayRef(opts::BatDumpCategories));
  cl::ParseCommandLineOptions(argc, argv, "");

  if (!sys::fs::exists(opts::InputFilename))
    report_error(opts::InputFilename, errc::no_such_file_or_directory);

  ToolName = argv[0];
  std::string ToolPath = GetExecutablePath(argv[0]);
  Expected<llvm::object::OwningBinary<llvm::object::Binary>> BinaryOrErr =
      llvm::object::createBinary(opts::InputFilename);
  if (Error E = BinaryOrErr.takeError())
    report_error(opts::InputFilename, std::move(E));
  llvm::object::Binary &Binary = *BinaryOrErr.get().getBinary();

  if (auto *InputFile = dyn_cast<llvm::object::ELFObjectFileBase>(&Binary))
    dumpBATFor(InputFile);
  else
    report_error(opts::InputFilename,
                 llvm::object::object_error::invalid_file_type);

  return EXIT_SUCCESS;
}