blob: cf30772c042ca0f58de6a323729d97004dbf7715 [file] [log] [blame]
// 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 <stddef.h>
#include <functional>
#include "gn/label.h"
class Config;
class ParseNode;
class Target;
// Structure that holds a labeled "thing". This is used for various places
// where we need to store lists of targets or configs. We sometimes populate
// the pointers on another thread from where we compute the labels, so this
// structure lets us save them separately. This also allows us to store the
// location of the thing that added this dependency.
template <typename T>
struct LabelPtrPair {
using DestType = T;
LabelPtrPair() = default;
explicit LabelPtrPair(const Label& l) : label(l) {}
// This constructor is typically used in unit tests, it extracts the label
// automatically from a given pointer.
explicit LabelPtrPair(const T* p) : label(p->label()), ptr(p) {}
~LabelPtrPair() = default;
Label label;
const T* ptr = nullptr;
// The origin of this dependency. This will be null for internally generated
// dependencies. This happens when a group is automatically expanded and that
// group's members are added to the target that depends on that group.
const ParseNode* origin = nullptr;
using LabelConfigPair = LabelPtrPair<Config>;
using LabelTargetPair = LabelPtrPair<Target>;
using LabelConfigVector = std::vector<LabelConfigPair>;
using LabelTargetVector = std::vector<LabelTargetPair>;
// Default comparison operators -----------------------------------------------
// The default hash and comparison operators operate on the label, which should
// always be valid, whereas the pointer is sometimes null.
template <typename T>
inline bool operator==(const LabelPtrPair<T>& a, const LabelPtrPair<T>& b) {
return a.label == b.label;
template <typename T>
inline bool operator<(const LabelPtrPair<T>& a, const LabelPtrPair<T>& b) {
return a.label < b.label;
namespace std {
template <typename T>
struct hash<LabelPtrPair<T>> {
std::size_t operator()(const LabelPtrPair<T>& v) const {
hash<Label> h;
return h(v.label);
} // namespace std