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

trunk/src/tools/gn/config.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/config.h"
-
-#include "tools/gn/err.h"
-#include "tools/gn/input_file_manager.h"
-#include "tools/gn/item_node.h"
-#include "tools/gn/item_tree.h"
-#include "tools/gn/scheduler.h"
-
-Config::Config(const Label& label) : Item(label) {
-}
-
-Config::~Config() {
-}
-
-Config* Config::AsConfig() {
-  return this;
-}
-
-const Config* Config::AsConfig() const {
-  return this;
-}
-
-// static
-Config* Config::GetConfig(const Settings* settings,
-                          const LocationRange& specified_from_here,
-                          const Label& label,
-                          Item* dep_from,
-                          Err* err) {
-  DCHECK(!label.is_null());
-
-  ItemTree* tree = &settings->build_settings()->item_tree();
-  base::AutoLock lock(tree->lock());
-
-  ItemNode* node = tree->GetExistingNodeLocked(label);
-  Config* config = NULL;
-  if (!node) {
-    config = new Config(label);
-    node = new ItemNode(config);
-    tree->AddNodeLocked(node);
-
-    // Only schedule loading the given target if somebody is depending on it
-    // (and we optimize by not re-asking it to run the current file).
-    // Otherwise, we're probably generating it right now.
-    if (dep_from && dep_from->label().dir() != label.dir()) {
-      settings->build_settings()->toolchain_manager().ScheduleInvocationLocked(
-          specified_from_here, label.GetToolchainLabel(), label.dir(),
-          err);
-    }
-  } else if ((config = node->item()->AsConfig())) {
-    // Previously saw this item as a config.
-
-    // If we have no dep_from, we're generating it. In this case, it had better
-    // not already be generated.
-    if (!dep_from && node->state() != ItemNode::REFERENCED) {
-      *err = Err(specified_from_here, "Duplicate config definition.",
-          "You already told me about a config with this name.");
-      return NULL;
-    }
-  } else {
-    // Previously saw this thing as a non-config.
-    *err = Err(specified_from_here,
-               "Config name already used.",
-               "Previously you specified a " +
-               node->item()->GetItemTypeName() + " with this name instead.");
-    return NULL;
-  }
-
-  // Keep a record of the guy asking us for this dependency. We know if
-  // somebody is adding a dependency, that guy it himself not resolved.
-  if (dep_from && node->state() != ItemNode::RESOLVED)
-    tree->GetExistingNodeLocked(dep_from->label())->AddDependency(node);
-
-  return config;
-}