// -*- mode: c++ -*-

// Copyright (c) 2011, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// dump_syms_tool.cc: Command line tool that uses the DumpSymbols class.
// TODO(waylonis): accept stdin

#include <mach-o/arch.h>
#include <unistd.h>

#include <algorithm>
#include <iostream>
#include <vector>

#include "common/mac/dump_syms.h"
#include "common/mac/arch_utilities.h"
#include "common/mac/macho_utilities.h"
#include "common/scoped_ptr.h"

using google_breakpad::DumpSymbols;
using google_breakpad::Module;
using google_breakpad::scoped_ptr;
using std::vector;

struct Options {
  Options()
      : srcPath(), dsymPath(), arch(), header_only(false),
        cfi(true), handle_inter_cu_refs(true) {}

  string srcPath;
  string dsymPath;
  const NXArchInfo *arch;
  bool header_only;
  bool cfi;
  bool handle_inter_cu_refs;
};

static bool StackFrameEntryComparator(const Module::StackFrameEntry* a,
                                      const Module::StackFrameEntry* b) {
  return a->address < b->address;
}

// Copy the CFI data from |from_module| into |to_module|, for any non-
// overlapping ranges.
static void CopyCFIDataBetweenModules(Module* to_module,
                                      const Module* from_module) {
  typedef vector<Module::StackFrameEntry*>::const_iterator Iterator;

  // Get the CFI data from both the source and destination modules and ensure
  // it is sorted by start address.
  vector<Module::StackFrameEntry*> from_data;
  from_module->GetStackFrameEntries(&from_data);
  std::sort(from_data.begin(), from_data.end(), &StackFrameEntryComparator);

  vector<Module::StackFrameEntry*> to_data;
  to_module->GetStackFrameEntries(&to_data);
  std::sort(to_data.begin(), to_data.end(), &StackFrameEntryComparator);

  Iterator to_it = to_data.begin();

  for (Iterator it = from_data.begin(); it != from_data.end(); ++it) {
    Module::StackFrameEntry* from_entry = *it;
    Module::Address from_entry_end = from_entry->address + from_entry->size;

    // Find the first CFI record in the |to_module| that does not have an
    // address less than the entry to be copied.
    while (to_it != to_data.end()) {
      if (from_entry->address > (*to_it)->address)
        ++to_it;
      else
        break;
    }

    // If the entry does not overlap, then it is safe to copy to |to_module|.
    if (to_it == to_data.end() || (from_entry->address < (*to_it)->address &&
            from_entry_end < (*to_it)->address)) {
      to_module->AddStackFrameEntry(new Module::StackFrameEntry(*from_entry));
    }
  }
}

static bool Start(const Options& options) {
  SymbolData symbol_data = options.cfi ? ALL_SYMBOL_DATA : NO_CFI;
  DumpSymbols dump_symbols(symbol_data, options.handle_inter_cu_refs);

  // For x86_64 binaries, the CFI data is in the __TEXT,__eh_frame of the
  // Mach-O file, which is not copied into the dSYM. Whereas in i386, the CFI
  // data is in the __DWARF,__debug_frame section, which is moved into the
  // dSYM. Therefore, to get x86_64 CFI data, dump_syms needs to look at both
  // the dSYM and the Mach-O file. If both paths are present and CFI was
  // requested, then consider the Module as "split" and dump all the debug data
  // from the primary debug info file, the dSYM, and then dump additional CFI
  // data from the source Mach-O file.
  bool split_module =
    !options.dsymPath.empty() && !options.srcPath.empty() && options.cfi;
  const string& primary_file =
    split_module ? options.dsymPath : options.srcPath;

  if (!dump_symbols.Read(primary_file))
    return false;

  if (options.arch) {
    if (!dump_symbols.SetArchitecture(options.arch->cputype,
                                      options.arch->cpusubtype)) {
      fprintf(stderr, "%s: no architecture '%s' is present in file.\n",
              primary_file.c_str(), options.arch->name);
      size_t available_size;
      const SuperFatArch *available =
        dump_symbols.AvailableArchitectures(&available_size);
      if (available_size == 1)
        fprintf(stderr, "the file's architecture is: ");
      else
        fprintf(stderr, "architectures present in the file are:\n");
      for (size_t i = 0; i < available_size; i++) {
        const SuperFatArch *arch = &available[i];
        const NXArchInfo *arch_info =
          google_breakpad::BreakpadGetArchInfoFromCpuType(
              arch->cputype, arch->cpusubtype);
        if (arch_info)
          fprintf(stderr, "%s (%s)\n", arch_info->name, arch_info->description);
        else
          fprintf(stderr, "unrecognized cpu type 0x%x, subtype 0x%x\n",
                  arch->cputype, arch->cpusubtype);
      }
      return false;
    }
  }

  if (options.header_only)
    return dump_symbols.WriteSymbolFileHeader(std::cout);

  // Read the primary file into a Breakpad Module.
  Module* module = NULL;
  if (!dump_symbols.ReadSymbolData(&module))
    return false;
  scoped_ptr<Module> scoped_module(module);

  // If this is a split module, read the secondary Mach-O file, from which the
  // CFI data will be extracted.
  if (split_module && primary_file == options.dsymPath) {
    if (!dump_symbols.Read(options.srcPath))
      return false;

    Module* cfi_module = NULL;
    if (!dump_symbols.ReadSymbolData(&cfi_module))
      return false;
    scoped_ptr<Module> scoped_cfi_module(cfi_module);

    // Ensure that the modules are for the same debug code file.
    if (cfi_module->name() != module->name() ||
        cfi_module->os() != module->os() ||
        cfi_module->architecture() != module->architecture() ||
        cfi_module->identifier() != module->identifier()) {
      fprintf(stderr, "Cannot generate a symbol file from split sources that do"
                      " not match.\n");
      return false;
    }

    CopyCFIDataBetweenModules(module, cfi_module);
  }

  return module->Write(std::cout, symbol_data);
}

//=============================================================================
static void Usage(int argc, const char *argv[]) {
  fprintf(stderr, "Output a Breakpad symbol file from a Mach-o file.\n");
  fprintf(stderr, "Usage: %s [-a ARCHITECTURE] [-c] [-g dSYM path] "
                  "<Mach-o file>\n", argv[0]);
  fprintf(stderr, "\t-i: Output module header information only.\n");
  fprintf(stderr, "\t-a: Architecture type [default: native, or whatever is\n");
  fprintf(stderr, "\t    in the file, if it contains only one architecture]\n");
  fprintf(stderr, "\t-g: Debug symbol file (dSYM) to dump in addition to the "
                  "Mach-o file\n");
  fprintf(stderr, "\t-c: Do not generate CFI section\n");
  fprintf(stderr, "\t-r: Do not handle inter-compilation unit references\n");
  fprintf(stderr, "\t-h: Usage\n");
  fprintf(stderr, "\t-?: Usage\n");
}

//=============================================================================
static void SetupOptions(int argc, const char *argv[], Options *options) {
  extern int optind;
  signed char ch;

  while ((ch = getopt(argc, (char * const*)argv, "ia:g:chr?")) != -1) {
    switch (ch) {
      case 'i':
        options->header_only = true;
        break;
      case 'a': {
        const NXArchInfo *arch_info =
            google_breakpad::BreakpadGetArchInfoFromName(optarg);
        if (!arch_info) {
          fprintf(stderr, "%s: Invalid architecture: %s\n", argv[0], optarg);
          Usage(argc, argv);
          exit(1);
        }
        options->arch = arch_info;
        break;
      }
      case 'g':
        options->dsymPath = optarg;
        break;
      case 'c':
        options->cfi = false;
        break;
      case 'r':
        options->handle_inter_cu_refs = false;
        break;
      case '?':
      case 'h':
        Usage(argc, argv);
        exit(0);
        break;
    }
  }

  if ((argc - optind) != 1) {
    fprintf(stderr, "Must specify Mach-o file\n");
    Usage(argc, argv);
    exit(1);
  }

  options->srcPath = argv[optind];
}

//=============================================================================
int main (int argc, const char * argv[]) {
  Options options;
  bool result;

  SetupOptions(argc, argv, &options);
  result = Start(options);

  return !result;
}