tools/gn/label.h

   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
  12 class Err;
  13 class 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.
  18 class 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   // Returns true if the toolchain dir/name of this object matches some
  87   // other object.
  88   bool ToolchainsEqual(const Label& other) const {
  89     return toolchain_dir_ == other.toolchain_dir_ &&
  90            toolchain_name_ == other.toolchain_name_;
  91   }
  92
  93  private:
  94   SourceDir dir_;
  95   std::string name_;
  96
  97   SourceDir toolchain_dir_;
  98   std::string toolchain_name_;
  99 };
 100
 101 namespace BASE_HASH_NAMESPACE {
 102
 103 #if defined(COMPILER_GCC)
 104 template<> struct hash<Label> {
 105   std::size_t operator()(const Label& v) const {
 106     hash<std::string> stringhash;
 107     return ((stringhash(v.dir().value()) * 131 +
 108              stringhash(v.name())) * 131 +
 109             stringhash(v.toolchain_dir().value())) * 131 +
 110            stringhash(v.toolchain_name());
 111   }
 112 };
 113 #elif defined(COMPILER_MSVC)
 114 inline size_t hash_value(const Label& v) {
 115   return ((hash_value(v.dir().value()) * 131 +
 116            hash_value(v.name())) * 131 +
 117           hash_value(v.toolchain_dir().value())) * 131 +
 118          hash_value(v.toolchain_name());
 119 }
 120 #endif  // COMPILER...
 121
 122 }  // namespace BASE_HASH_NAMESPACE
 123
 124 #endif  // TOOLS_GN_LABEL_H_