text: // Copyright (c) 2013 The Chromium 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 "tools/gn/ninja_toolchain_writer.h"
  
  #include <fstream>
  
  #include "base/files/file_util.h"
  #include "base/strings/stringize_macros.h"
  #include "tools/gn/build_settings.h"
  #include "tools/gn/filesystem_utils.h"
  #include "tools/gn/ninja_utils.h"
  #include "tools/gn/pool.h"
  #include "tools/gn/settings.h"
  #include "tools/gn/substitution_writer.h"
  #include "tools/gn/target.h"
  #include "tools/gn/toolchain.h"
  #include "tools/gn/trace.h"
  
  namespace {
  
  const char kIndent[] = "  ";
  
  }  // namespace
  
  NinjaToolchainWriter::NinjaToolchainWriter(
      const Settings* settings,
      const Toolchain* toolchain,
      std::ostream& out)
      : settings_(settings),
        toolchain_(toolchain),
        out_(out),
        path_output_(settings_->build_settings()->build_dir(),
                     settings_->build_settings()->root_path_utf8(),
                     ESCAPE_NINJA) {
  }
  
  NinjaToolchainWriter::~NinjaToolchainWriter() = default;
  
  void NinjaToolchainWriter::Run(
      const std::vector<NinjaWriter::TargetRulePair>& rules) {
    std::string rule_prefix = GetNinjaRulePrefixForToolchain(settings_);
  
    for (int i = Toolchain::TYPE_NONE + 1; i < Toolchain::TYPE_NUMTYPES; i++) {
      Toolchain::ToolType tool_type = static_cast<Toolchain::ToolType>(i);
      const Tool* tool = toolchain_->GetTool(tool_type);
      if (tool_type == Toolchain::TYPE_ACTION)
        continue;
      if (tool)
        WriteToolRule(tool_type, tool, rule_prefix);
    }
    out_ << std::endl;
  
    for (const auto& pair : rules)
      out_ << pair.second;
  }
  
  // static
  bool NinjaToolchainWriter::RunAndWriteFile(
      const Settings* settings,
      const Toolchain* toolchain,
      const std::vector<NinjaWriter::TargetRulePair>& rules) {
    base::FilePath ninja_file(settings->build_settings()->GetFullPath(
        GetNinjaFileForToolchain(settings)));
    ScopedTrace trace(TraceItem::TRACE_FILE_WRITE, FilePathToUTF8(ninja_file));
  
    base::CreateDirectory(ninja_file.DirName());
  
    std::ofstream file;
    file.open(FilePathToUTF8(ninja_file).c_str(),
              std::ios_base::out | std::ios_base::binary);
    if (file.fail())
      return false;
  
    NinjaToolchainWriter gen(settings, toolchain, file);
    gen.Run(rules);
    return true;
  }
  
  void NinjaToolchainWriter::WriteToolRule(const Toolchain::ToolType type,
                                           const Tool* tool,
                                           const std::string& rule_prefix) {
    out_ << "rule " << rule_prefix << Toolchain::ToolTypeToName(type)
         << std::endl;
  
    // Rules explicitly include shell commands, so don't try to escape.
    EscapeOptions options;
    options.mode = ESCAPE_NINJA_PREFORMATTED_COMMAND;
  
    CHECK(!tool->command().empty()) << "Command should not be empty";
    WriteRulePattern("command", tool->command(), options);
  
    WriteRulePattern("description", tool->description(), options);
    WriteRulePattern("rspfile", tool->rspfile(), options);
    WriteRulePattern("rspfile_content", tool->rspfile_content(), options);
  
    if (tool->depsformat() == Tool::DEPS_GCC) {
      // GCC-style deps require a depfile.
      if (!tool->depfile().empty()) {
        WriteRulePattern("depfile", tool->depfile(), options);
        out_ << kIndent << "deps = gcc" << std::endl;
      }
    } else if (tool->depsformat() == Tool::DEPS_MSVC) {
      // MSVC deps don't have a depfile.
      out_ << kIndent << "deps = msvc" << std::endl;
    }
  
    // Use pool is specified.
    if (tool->pool().ptr) {
      std::string pool_name =
          tool->pool().ptr->GetNinjaName(settings_->default_toolchain_label());
      out_ << kIndent << "pool = " << pool_name << std::endl;
    }
  
    if (tool->restat())
      out_ << kIndent << "restat = 1" << std::endl;
  }
  
  void NinjaToolchainWriter::WriteRulePattern(const char* name,
                                              const SubstitutionPattern& pattern,
                                              const EscapeOptions& options) {
    if (pattern.empty())
      return;
    out_ << kIndent << name << " = ";
    SubstitutionWriter::WriteWithNinjaVariables(pattern, options, out_);
    out_ << std::endl;
  }
  