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

trunk/src/tools/gn/function_template.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/functions.h"
-
-#include "tools/gn/parse_tree.h"
-#include "tools/gn/scope.h"
-#include "tools/gn/value.h"
-
-Value ExecuteTemplate(Scope* scope,
-                      const FunctionCallNode* function,
-                      const std::vector<Value>& args,
-                      BlockNode* block,
-                      Err* err) {
-  // TODO(brettw) determine if the function is built-in and throw an error if
-  // it is.
-  if (args.size() != 1) {
-    *err = Err(function->function(),
-               "Need exactly one string arg to template.");
-    return Value();
-  }
-  if (!args[0].VerifyTypeIs(Value::STRING, err))
-    return Value();
-  std::string template_name = args[0].string_value();
-
-  const FunctionCallNode* existing_template = scope->GetTemplate(template_name);
-  if (existing_template) {
-    *err = Err(function, "Duplicate template definition.",
-               "A template with this name was already defined.");
-    err->AppendSubErr(Err(existing_template->function(),
-                          "Previous definition."));
-    return Value();
-  }
-
-  scope->AddTemplate(template_name, function);
-  return Value();
-}