GN: toolchain threading cleanup

tools/gn/ninja_toolchain_writer.cc

 // 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/file_util.h"
 #include "base/strings/stringize_macros.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/item_node.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/target.h"
 #include "tools/gn/toolchain.h"
+#include "tools/gn/toolchain_manager.h"
 #include "tools/gn/trace.h"
 
 NinjaToolchainWriter::NinjaToolchainWriter(
     const Settings* settings,
     const std::vector<const Target*>& targets,
     const std::set<std::string>& skip_files,
     std::ostream& out)
     : settings_(settings),
       targets_(targets),
       skip_files_(skip_files),
@@ skipping 29 matching lines @@
             std::ios_base::out | std::ios_base::binary);
   if (file.fail())
     return false;
 
   NinjaToolchainWriter gen(settings, targets, skip_files, file);
   gen.Run();
   return true;
 }
 
 void NinjaToolchainWriter::WriteRules() {
-  const Toolchain* tc = settings_->toolchain();
+  const Toolchain* tc = settings_->build_settings()->toolchain_manager()
+      .GetToolchainDefinitionUnlocked(settings_->toolchain_label());
+  CHECK(tc);
+
   std::string indent("  ");
 
   NinjaHelper helper(settings_->build_settings());
-  std::string rule_prefix = helper.GetRulePrefix(tc);
+  std::string rule_prefix = helper.GetRulePrefix(settings_);
 
   for (int i = Toolchain::TYPE_NONE + 1; i < Toolchain::TYPE_NUMTYPES; i++) {
     Toolchain::ToolType tool_type = static_cast<Toolchain::ToolType>(i);
     const Toolchain::Tool& tool = tc->GetTool(tool_type);
     if (tool.command.empty())
       continue;
 
     out_ << "rule " << rule_prefix << Toolchain::ToolTypeToName(tool_type)
          << std::endl;
 
@@ skipping 24 matching lines @@
     OutputFile ninja_file = helper_.GetNinjaFileForTarget(targets_[i]);
     if (skip_files_.find(ninja_file.value()) != skip_files_.end())
       continue;
 
     out_ << "subninja ";
     path_output_.WriteFile(out_, ninja_file);
     out_ << std::endl;
   }
   out_ << std::endl;
 }