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  ~Label();
29
30  // Resolives a string from a build file that may be relative to the
31  // current directory into a fully qualified label. On failure returns an
32  // is_null() label and sets the error.
33  static Label Resolve(const SourceDir& current_dir,
34                       const Label& current_toolchain,
35                       const Value& input,
36                       Err* err);
37
38  bool is_null() const { return dir_.is_null(); }
39
40  const SourceDir& dir() const { return dir_; }
41  const std::string& name() const { return name_; }
42
43  const SourceDir& toolchain_dir() const { return toolchain_dir_; }
44  const std::string& toolchain_name() const { return toolchain_name_; }
45  Label GetToolchainLabel() const;
46
47  // Formats this label in a way that we can present to the user or expose to
48  // other parts of the system. SourceDirs end in slashes, but the user
49  // expects names like "//chrome/renderer:renderer_config" when printed. The
50  // toolchain is optionally included.
51  std::string GetUserVisibleName(bool include_toolchain) const;
52
53  // Like the above version, but automatically includes the toolchain if it's
54  // not the default one. Normally the user only cares about the toolchain for
55  // non-default ones, so this can make certain output more clear.
56  std::string GetUserVisibleName(const Label& default_toolchain) const;
57
58  bool operator==(const Label& other) const {
59    return name_ == other.name_ && dir_ == other.dir_ &&
60           toolchain_dir_ == other.toolchain_dir_ &&
61           toolchain_name_ == other.toolchain_name_;
62  }
63  bool operator!=(const Label& other) const {
64    return !operator==(other);
65  }
66  bool operator<(const Label& other) const {
67    // TODO(brettw) could be optimized to avoid an extra full string check
68    // (one for operator==, one for <).
69    if (dir_ != other.dir_)
70      return dir_ < other.dir_;
71    if (name_ != other.name_)
72      return name_ < other.name_;
73    if (toolchain_dir_ != other.toolchain_dir_)
74      return toolchain_dir_ < other.toolchain_dir_;
75    return toolchain_name_ < other.toolchain_name_;
76  }
77
78  // Returns true if the toolchain dir/name of this object matches some
79  // other object.
80  bool ToolchainsEqual(const Label& other) const {
81    return toolchain_dir_ == other.toolchain_dir_ &&
82           toolchain_name_ == other.toolchain_name_;
83  }
84
85 private:
86  SourceDir dir_;
87  std::string name_;
88
89  SourceDir toolchain_dir_;
90  std::string toolchain_name_;
91};
92
93namespace BASE_HASH_NAMESPACE {
94
95#if defined(COMPILER_GCC)
96template<> struct hash<Label> {
97  std::size_t operator()(const Label& v) const {
98    hash<std::string> stringhash;
99    return ((stringhash(v.dir().value()) * 131 +
100             stringhash(v.name())) * 131 +
101            stringhash(v.toolchain_dir().value())) * 131 +
102           stringhash(v.toolchain_name());
103  }
104};
105#elif defined(COMPILER_MSVC)
106inline size_t hash_value(const Label& v) {
107  return ((hash_value(v.dir().value()) * 131 +
108           hash_value(v.name())) * 131 +
109          hash_value(v.toolchain_dir().value())) * 131 +
110         hash_value(v.toolchain_name());
111}
112#endif  // COMPILER...
113
114}  // namespace BASE_HASH_NAMESPACE
115
116#endif  // TOOLS_GN_LABEL_H_
117