1// Copyright (c) 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef TOOLS_GN_LABEL_H_
6#define TOOLS_GN_LABEL_H_
7
8#include "base/containers/hash_tables.h"
9#include "build/build_config.h"
10#include "tools/gn/source_dir.h"
11
12class Err;
13class Value;
14
15// A label represents the name of a target or some other named thing in
16// the source path. The label is always absolute and always includes a name
17// part, so it starts with a slash, and has one colon.
18class Label {
19 public:
20  Label();
21
22  // Makes a label given an already-separate out path and name.
23  // See also Resolve().
24  Label(const SourceDir& dir,
25        const base::StringPiece& name,
26        const SourceDir& toolchain_dir,
27        const base::StringPiece& toolchain_name);
28
29  // Makes a label with an empty toolchain.
30  Label(const SourceDir& dir, const base::StringPiece& name);
31  ~Label();
32
33  // Resolives a string from a build file that may be relative to the
34  // current directory into a fully qualified label. On failure returns an
35  // is_null() label and sets the error.
36  static Label Resolve(const SourceDir& current_dir,
37                       const Label& current_toolchain,
38                       const Value& input,
39                       Err* err);
40
41  bool is_null() const { return dir_.is_null(); }
42
43  const SourceDir& dir() const { return dir_; }
44  const std::string& name() const { return name_; }
45
46  const SourceDir& toolchain_dir() const { return toolchain_dir_; }
47  const std::string& toolchain_name() const { return toolchain_name_; }
48
49  // Returns the current label's toolchain as its own Label.
50  Label GetToolchainLabel() const;
51
52  // Returns a copy of this label but with an empty toolchain.
53  Label GetWithNoToolchain() const;
54
55  // Formats this label in a way that we can present to the user or expose to
56  // other parts of the system. SourceDirs end in slashes, but the user
57  // expects names like "//chrome/renderer:renderer_config" when printed. The
58  // toolchain is optionally included.
59  std::string GetUserVisibleName(bool include_toolchain) const;
60
61  // Like the above version, but automatically includes the toolchain if it's
62  // not the default one. Normally the user only cares about the toolchain for
63  // non-default ones, so this can make certain output more clear.
64  std::string GetUserVisibleName(const Label& default_toolchain) const;
65
66  bool operator==(const Label& other) const {
67    return name_ == other.name_ && dir_ == other.dir_ &&
68           toolchain_dir_ == other.toolchain_dir_ &&
69           toolchain_name_ == other.toolchain_name_;
70  }
71  bool operator!=(const Label& other) const {
72    return !operator==(other);
73  }
74  bool operator<(const Label& other) const {
75    // TODO(brettw) could be optimized to avoid an extra full string check
76    // (one for operator==, one for <).
77    if (dir_ != other.dir_)
78      return dir_ < other.dir_;
79    if (name_ != other.name_)
80      return name_ < other.name_;
81    if (toolchain_dir_ != other.toolchain_dir_)
82      return toolchain_dir_ < other.toolchain_dir_;
83    return toolchain_name_ < other.toolchain_name_;
84  }
85
86  void swap(Label& other) {
87    dir_.swap(other.dir_);
88    name_.swap(other.name_);
89    toolchain_dir_.swap(other.toolchain_dir_);
90    toolchain_name_.swap(other.toolchain_name_);
91  }
92
93  // Returns true if the toolchain dir/name of this object matches some
94  // other object.
95  bool ToolchainsEqual(const Label& other) const {
96    return toolchain_dir_ == other.toolchain_dir_ &&
97           toolchain_name_ == other.toolchain_name_;
98  }
99
100 private:
101  SourceDir dir_;
102  std::string name_;
103
104  SourceDir toolchain_dir_;
105  std::string toolchain_name_;
106};
107
108namespace BASE_HASH_NAMESPACE {
109
110#if defined(COMPILER_GCC)
111template<> struct hash<Label> {
112  std::size_t operator()(const Label& v) const {
113    hash<std::string> stringhash;
114    return ((stringhash(v.dir().value()) * 131 +
115             stringhash(v.name())) * 131 +
116            stringhash(v.toolchain_dir().value())) * 131 +
117           stringhash(v.toolchain_name());
118  }
119};
120#elif defined(COMPILER_MSVC)
121inline size_t hash_value(const Label& v) {
122  return ((hash_value(v.dir().value()) * 131 +
123           hash_value(v.name())) * 131 +
124          hash_value(v.toolchain_dir().value())) * 131 +
125         hash_value(v.toolchain_name());
126}
127#endif  // COMPILER...
128
129}  // namespace BASE_HASH_NAMESPACE
130
131inline void swap(Label& lhs, Label& rhs) {
132  lhs.swap(rhs);
133}
134
135#endif  // TOOLS_GN_LABEL_H_
136