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

trunk/src/tools/gn/item_node.h

-// 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.
-
-#ifndef TOOLS_GN_ITEM_NODE_H_
-#define TOOLS_GN_ITEM_NODE_H_
-
-#include <set>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/memory/scoped_ptr.h"
-#include "tools/gn/location.h"
-
-class Item;
-
-// Represents a node in the depdency tree. It references an Item which is
-// the actual thing.
-//
-// The items and nodes are split apart so that the ItemTree can manipulate
-// the dependencies one one thread while the Item itself is been modified on
-// another.
-class ItemNode {
- public:
-  enum State {
-    // Another item has referenced this one by name, but we have not yet
-    // encountered this item to know what it is.
-    REFERENCED,
-
-    // This item has been defined but some of the dependencies it references
-    // have not been.
-    GENERATED,
-
-    // All of this item's transitive dependencies have been found and
-    // resolved.
-    RESOLVED,
-  };
-
-  typedef std::set<ItemNode*> ItemNodeSet;
-
-  // Takes ownership of the pointer.
-  // Initial state will be REFERENCED.
-  ItemNode(Item* i);
-  ~ItemNode();
-
-  State state() const { return state_; }
-
-  // This closure will be executed when the item is resolved.
-  void set_resolved_closure(const base::Closure& closure) {
-    resolved_closure_ = closure;
-  }
-
-  const Item* item() const { return item_.get(); }
-  Item* item() { return item_.get(); }
-
-  // Where this was created from, which might be when it was generated or
-  // when it was first referenced from another target.
-  const LocationRange& originally_referenced_from_here() const {
-    return originally_referenced_from_here_;
-  }
-  void set_originally_referenced_from_here(const LocationRange& r) {
-    originally_referenced_from_here_ = r;
-  }
-
-  // Where this was generated from. This will be empty for items that have
-  // been referenced but not generated. Note that this has to be one the
-  // ItemNode because it can be changing from multiple threads and we need
-  // to be sure that access is serialized.
-  const LocationRange& generated_from_here() const {
-    return generated_from_here_;
-  }
-  void set_generated_from_here(const LocationRange& r) {
-    generated_from_here_ = r;
-  }
-
-  const ItemNodeSet& direct_dependencies() const {
-    return direct_dependencies_;
-  }
-  const ItemNodeSet& unresolved_dependencies() const {
-    return unresolved_dependencies_;
-  }
-
-  void AddDependency(ItemNode* node);
-
-  // Removes the given dependency from the unresolved list. Does not do
-  // anything else to update waiters.
-  void MarkDirectDependencyResolved(ItemNode* node);
-
-  // Destructively retrieve the set of waiting nodes.
-  void SwapOutWaitingDependencySet(ItemNodeSet* out_set);
-
-  void SetGenerated();
-  void SetResolved();
-
- private:
-  State state_;
-  scoped_ptr<Item> item_;
-
-  LocationRange originally_referenced_from_here_;
-  LocationRange generated_from_here_;
-
-  // What to run when this item is resolved.
-  base::Closure resolved_closure_;
-
-  // Everything this item directly depends on.
-  ItemNodeSet direct_dependencies_;
-
-  // Unresolved things this item directly depends on.
-  ItemNodeSet unresolved_dependencies_;
-
-  // These items are waiting on us to be resolved before they can be
-  // resolved. This is the backpointer for unresolved_dependencies_.
-  ItemNodeSet waiting_on_resolution_;
-
-  DISALLOW_COPY_AND_ASSIGN(ItemNode);
-};
-
-#endif  // TOOLS_GN_ITEM_NODE_H_