GN: toolchain threading cleanup

tools/gn/ninja_helper.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_helper.h"
 
 #include "base/logging.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/string_utils.h"
 #include "tools/gn/target.h"
@@ skipping 171 matching lines @@
                     target->label().dir().SourceAbsoluteWithOneSlash());
   ret.value().append(prefix);
   ret.value().append(name);
   if (extension[0]) {
     ret.value().push_back('.');
     ret.value().append(extension);
   }
   return ret;
 }
 
-std::string NinjaHelper::GetRulePrefix(const Toolchain* toolchain) const {
-  // This code doesn't prefix the default toolchain commands. This is disabled
-  // so we can coexist with GYP's commands (which aren't prefixed). If we don't
-  // need to coexist with GYP anymore, we can uncomment this to make things a
-  // bit prettier.
-  //if (toolchain->is_default())
-  //  return std::string();  // Default toolchain has no prefix.
-  return toolchain->label().name() + "_";
+std::string NinjaHelper::GetRulePrefix(const Settings* settings) const {
+  // Don't prefix the default toolchain so it looks prettier, prefix everything
+  // else.
+  if (settings->is_default())
+    return std::string();  // Default toolchain has no prefix.
+  return settings->toolchain_label().name() + "_";
 }
 
 std::string NinjaHelper::GetRuleForSourceType(const Settings* settings,
-                                              const Toolchain* toolchain,
                                               SourceFileType type) const {
   // This function may be hot since it will be called for every source file
   // in the tree. We could cache the results to avoid making a string for
   // every invocation.
-  std::string prefix = GetRulePrefix(toolchain);
+  std::string prefix = GetRulePrefix(settings);
 
   if (type == SOURCE_C)
     return prefix + "cc";
   if (type == SOURCE_CC)
     return prefix + "cxx";
 
   // TODO(brettw) asm files.
 
   if (settings->IsMac()) {
     if (type == SOURCE_M)
       return prefix + "objc";
     if (type == SOURCE_MM)
       return prefix + "objcxx";
   }
 
   if (settings->IsWin()) {
     if (type == SOURCE_RC)
       return prefix + "rc";
   } else {
     if (type == SOURCE_S)
       return prefix + "cc";  // Assembly files just get compiled by CC.
   }
 
   return std::string();
 }