shell/common/switches.cc

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <algorithm>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>

#include "flutter/fml/native_library.h"
#include "flutter/fml/paths.h"
#include "flutter/fml/string_view.h"
#include "flutter/shell/version/version.h"

// Include once for the default enum definition.
#include "flutter/shell/common/switches.h"

#undef SHELL_COMMON_SWITCHES_H_

struct SwitchDesc {
  flutter::Switch sw;
  const fml::StringView flag;
  const char* help;
};

#undef DEF_SWITCHES_START
#undef DEF_SWITCH
#undef DEF_SWITCHES_END

// clang-format off
#define DEF_SWITCHES_START static const struct SwitchDesc gSwitchDescs[] = {
#define DEF_SWITCH(p_swtch, p_flag, p_help) \
  { flutter::Switch:: p_swtch, p_flag, p_help },
#define DEF_SWITCHES_END };
// clang-format on

// Include again for struct definition.
#include "flutter/shell/common/switches.h"

namespace flutter {

void PrintUsage(const std::string& executable_name) {
  std::cerr << std::endl << "  " << executable_name << std::endl << std::endl;

  std::cerr << "Versions: " << std::endl << std::endl;

  std::cerr << "Flutter Engine Version: " << GetFlutterEngineVersion()
            << std::endl;
  std::cerr << "Skia Version: " << GetSkiaVersion() << std::endl;

  std::cerr << "Dart Version: " << GetDartVersion() << std::endl << std::endl;

  std::cerr << "Available Flags:" << std::endl;

  const uint32_t column_width = 80;

  const uint32_t flags_count = static_cast<uint32_t>(Switch::Sentinel);

  uint32_t max_width = 2;
  for (uint32_t i = 0; i < flags_count; i++) {
    auto desc = gSwitchDescs[i];
    max_width = std::max<uint32_t>(desc.flag.size() + 2, max_width);
  }

  const uint32_t help_width = column_width - max_width - 3;

  std::cerr << std::string(column_width, '-') << std::endl;
  for (uint32_t i = 0; i < flags_count; i++) {
    auto desc = gSwitchDescs[i];

    std::cerr << std::setw(max_width)
              << std::string("--") + desc.flag.ToString() << " : ";

    std::istringstream stream(desc.help);
    int32_t remaining = help_width;

    std::string word;
    while (stream >> word && remaining > 0) {
      remaining -= (word.size() + 1);
      if (remaining <= 0) {
        std::cerr << std::endl
                  << std::string(max_width, ' ') << "   " << word << " ";
        remaining = help_width;
      } else {
        std::cerr << word << " ";
      }
    }

    std::cerr << std::endl;
  }
  std::cerr << std::string(column_width, '-') << std::endl;
}

const fml::StringView FlagForSwitch(Switch swtch) {
  for (uint32_t i = 0; i < static_cast<uint32_t>(Switch::Sentinel); i++) {
    if (gSwitchDescs[i].sw == swtch) {
      return gSwitchDescs[i].flag;
    }
  }
  return fml::StringView();
}

template <typename T>
static bool GetSwitchValue(const fml::CommandLine& command_line,
                           Switch sw,
                           T* result) {
  std::string switch_string;

  if (!command_line.GetOptionValue(FlagForSwitch(sw), &switch_string)) {
    return false;
  }

  std::stringstream stream(switch_string);
  T value = 0;
  if (stream >> value) {
    *result = value;
    return true;
  }

  return false;
}

std::unique_ptr<fml::Mapping> GetSymbolMapping(std::string symbol_prefix,
                                               std::string native_lib_path) {
  const uint8_t* mapping;
  intptr_t size;

  auto lookup_symbol = [&mapping, &size, symbol_prefix](
                           const fml::RefPtr<fml::NativeLibrary>& library) {
    mapping = library->ResolveSymbol((symbol_prefix + "_start").c_str());
    size = reinterpret_cast<intptr_t>(
        library->ResolveSymbol((symbol_prefix + "_size").c_str()));
  };

  fml::RefPtr<fml::NativeLibrary> library =
      fml::NativeLibrary::CreateForCurrentProcess();
  lookup_symbol(library);

  if (!(mapping && size)) {
    // Symbol lookup for the current process fails on some devices.  As a
    // fallback, try doing the lookup based on the path to the Flutter library.
    library = fml::NativeLibrary::Create(native_lib_path.c_str());
    lookup_symbol(library);
  }

  FML_CHECK(mapping && size) << "Unable to resolve symbols: " << symbol_prefix;
  return std::make_unique<fml::NonOwnedMapping>(mapping, size);
}

Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
  Settings settings = {};

  // Enable Observatory
  settings.enable_observatory =
      !command_line.HasOption(FlagForSwitch(Switch::DisableObservatory));

  // Set Observatory Port
  if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryPort))) {
    if (!GetSwitchValue(command_line, Switch::DeviceObservatoryPort,
                        &settings.observatory_port)) {
      FML_LOG(INFO)
          << "Observatory port specified was malformed. Will default to "
          << settings.observatory_port;
    }
  }

  // Disable need for authentication codes for VM service communication, if
  // specified.
  settings.disable_service_auth_codes =
      command_line.HasOption(FlagForSwitch(Switch::DisableServiceAuthCodes));

  // Checked mode overrides.
  settings.disable_dart_asserts =
      command_line.HasOption(FlagForSwitch(Switch::DisableDartAsserts));

  settings.ipv6 = command_line.HasOption(FlagForSwitch(Switch::IPv6));

  settings.start_paused =
      command_line.HasOption(FlagForSwitch(Switch::StartPaused));

  settings.enable_dart_profiling =
      command_line.HasOption(FlagForSwitch(Switch::EnableDartProfiling));

  settings.enable_software_rendering =
      command_line.HasOption(FlagForSwitch(Switch::EnableSoftwareRendering));

  settings.endless_trace_buffer =
      command_line.HasOption(FlagForSwitch(Switch::EndlessTraceBuffer));

  settings.trace_startup =
      command_line.HasOption(FlagForSwitch(Switch::TraceStartup));

  settings.skia_deterministic_rendering_on_cpu =
      command_line.HasOption(FlagForSwitch(Switch::SkiaDeterministicRendering));

  settings.verbose_logging =
      command_line.HasOption(FlagForSwitch(Switch::VerboseLogging));

  command_line.GetOptionValue(FlagForSwitch(Switch::FlutterAssetsDir),
                              &settings.assets_path);

  std::string aot_shared_library_path;
  command_line.GetOptionValue(FlagForSwitch(Switch::AotSharedLibraryPath),
                              &aot_shared_library_path);

  std::string aot_snapshot_path;
  command_line.GetOptionValue(FlagForSwitch(Switch::AotSnapshotPath),
                              &aot_snapshot_path);

  std::string aot_vm_snapshot_data_filename;
  command_line.GetOptionValue(FlagForSwitch(Switch::AotVmSnapshotData),
                              &aot_vm_snapshot_data_filename);

  std::string aot_vm_snapshot_instr_filename;
  command_line.GetOptionValue(FlagForSwitch(Switch::AotVmSnapshotInstructions),
                              &aot_vm_snapshot_instr_filename);

  std::string aot_isolate_snapshot_data_filename;
  command_line.GetOptionValue(FlagForSwitch(Switch::AotIsolateSnapshotData),
                              &aot_isolate_snapshot_data_filename);

  std::string aot_isolate_snapshot_instr_filename;
  command_line.GetOptionValue(
      FlagForSwitch(Switch::AotIsolateSnapshotInstructions),
      &aot_isolate_snapshot_instr_filename);

  if (aot_shared_library_path.size() > 0) {
    settings.application_library_path = aot_shared_library_path;
  } else if (aot_snapshot_path.size() > 0) {
    settings.vm_snapshot_data_path = fml::paths::JoinPaths(
        {aot_snapshot_path, aot_vm_snapshot_data_filename});
    settings.vm_snapshot_instr_path = fml::paths::JoinPaths(
        {aot_snapshot_path, aot_vm_snapshot_instr_filename});
    settings.isolate_snapshot_data_path = fml::paths::JoinPaths(
        {aot_snapshot_path, aot_isolate_snapshot_data_filename});
    settings.isolate_snapshot_instr_path = fml::paths::JoinPaths(
        {aot_snapshot_path, aot_isolate_snapshot_instr_filename});
  }

  command_line.GetOptionValue(FlagForSwitch(Switch::CacheDirPath),
                              &settings.temp_directory_path);

  {
    // ICU from a data file.
    std::string icu_data_path;
    command_line.GetOptionValue(FlagForSwitch(Switch::ICUDataFilePath),
                                &icu_data_path);
    if (icu_data_path.size() > 0) {
      settings.icu_mapper = [icu_data_path]() {
        return fml::FileMapping::CreateReadOnly(icu_data_path);
      };
    }
  }

  {
    // ICU from a symbol in a dynamic library
    if (command_line.HasOption(FlagForSwitch(Switch::ICUSymbolPrefix))) {
      std::string icu_symbol_prefix, native_lib_path;
      command_line.GetOptionValue(FlagForSwitch(Switch::ICUSymbolPrefix),
                                  &icu_symbol_prefix);
      command_line.GetOptionValue(FlagForSwitch(Switch::ICUNativeLibPath),
                                  &native_lib_path);
      settings.icu_mapper = [icu_symbol_prefix, native_lib_path] {
        return GetSymbolMapping(icu_symbol_prefix, native_lib_path);
      };
    }
  }

  settings.use_test_fonts =
      command_line.HasOption(FlagForSwitch(Switch::UseTestFonts));

  command_line.GetOptionValue(FlagForSwitch(Switch::LogTag), &settings.log_tag);
  std::string all_dart_flags;
  if (command_line.GetOptionValue(FlagForSwitch(Switch::DartFlags),
                                  &all_dart_flags)) {
    std::stringstream stream(all_dart_flags);
    std::istream_iterator<std::string> end;
    for (std::istream_iterator<std::string> it(stream); it != end; ++it)
      settings.dart_flags.push_back(*it);
  }

#if FLUTTER_RUNTIME_MODE != FLUTTER_RUNTIME_MODE_RELEASE && \
    FLUTTER_RUNTIME_MODE != FLUTTER_RUNTIME_MODE_DYNAMIC_RELEASE
  settings.trace_skia =
      command_line.HasOption(FlagForSwitch(Switch::TraceSkia));
  settings.trace_systrace =
      command_line.HasOption(FlagForSwitch(Switch::TraceSystrace));
#endif

  settings.dump_skp_on_shader_compilation =
      command_line.HasOption(FlagForSwitch(Switch::DumpSkpOnShaderCompilation));

  return settings;
}

}  // namespace flutter