Revert 214254 "Add initial prototype for the GN meta-buildsystem."

trunk/src/tools/gn/function_set_default_toolchain.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/build_settings.h"
-#include "tools/gn/functions.h"
-#include "tools/gn/parse_tree.h"
-#include "tools/gn/scope.h"
-#include "tools/gn/settings.h"
-#include "tools/gn/toolchain_manager.h"
-
-/*
-set_default_toolchain: Sets the default toolchain name.
-
-  set_default_toolchain(toolchain_label)
-
-  The given label should identify a toolchain definition (see "toolchain").
-  This toolchain will be used for all targets unless otherwise specified.
-
-  This function is only valid to call during the processing of the build
-  configuration file. Since the build configuration file is processed
-  separately for each toolchain, this function will be a no-op when called
-  under any non-default toolchains.
-
-  For example, the default toolchain should be appropriate for the current
-  environment. If the current environment is 32-bit and somebody references
-  a target with a 64-bit toolchain, we wouldn't want processing of the build
-  config file for the 64-bit toolchain to reset the default toolchain to
-  64-bit, we want to keep it 32-bits.
-
-Argument:
-
-  toolchain_label:
-      Toolchain name.
-
-Example:
-
-  set_default_toolchain("//build/config/win:vs32")
-*/
-
-Value ExecuteSetDefaultToolchain(Scope* scope,
-                                 const FunctionCallNode* function,
-                                 const std::vector<Value>& args,
-                                 Err* err) {
-  if (!scope->IsProcessingBuildConfig()) {
-    *err = Err(function->function(), "Must be called from build config.",
-        "set_default_toolchain can only be called from the build configuration "
-        "file.");
-    return Value();
-  }
-
-  // Ignore non-default-build-config invocations.
-  if (!scope->IsProcessingDefaultBuildConfig())
-    return Value();
-
-  const SourceDir& current_dir = SourceDirForFunctionCall(function);
-  const Label& default_toolchain = ToolchainLabelForScope(scope);
-
-  if (!EnsureSingleStringArg(function, args, err))
-    return Value();
-  Label toolchain_label(
-      Label::Resolve(current_dir, default_toolchain, args[0], err));
-  if (toolchain_label.is_null())
-    return Value();
-
-  ToolchainManager& mgr =
-      scope->settings()->build_settings()->toolchain_manager();
-  mgr.SetDefaultToolchainUnlocked(toolchain_label, function->GetRange(), err);
-  return Value();
-}