tools/gn/source_dir.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_SOURCE_DIR_H_
   6 #define TOOLS_GN_SOURCE_DIR_H_
   7
   8 #include <string>
   9
  10 #include "base/containers/hash_tables.h"
  11 #include "base/files/file_path.h"
  12 #include "base/logging.h"
  13 #include "base/strings/string_piece.h"
  14
  15 class SourceFile;
  16
  17 // Represents a directory within the source tree. Source dirs begin and end in
  18 // slashes.
  19 //
  20 // If there is one slash at the beginning, it will mean a system-absolute file
  21 // path. On Windows, absolute system paths will be of the form "/C:/foo/bar".
  22 //
  23 // Two slashes at the beginning indicate a path relative to the source root.
  24 class SourceDir {
  25  public:
  26   SourceDir();
  27   explicit SourceDir(const base::StringPiece& p);
  28   ~SourceDir();
  29
  30   // Resolves a file or dir name relative to this source directory. Will return
  31   // an empty SourceDir/File on error. Empty input is always an error (it's
  32   // possible we should say ResolveRelativeDir vs. an empty string should be
  33   // the source dir, but we require "." instead).
  34   //
  35   // If source_root is supplied, these functions will additionally handle the
  36   // case where the input is a system-absolute but still inside the source
  37   // tree. This is the case for some external tools.
  38   SourceFile ResolveRelativeFile(
  39       const base::StringPiece& p,
  40       const base::StringPiece& source_root = base::StringPiece()) const;
  41   SourceDir ResolveRelativeDir(
  42       const base::StringPiece& p,
  43       const base::StringPiece& source_root = base::StringPiece()) const;
  44
  45   // Resolves this source file relative to some given source root. Returns
  46   // an empty file path on error.
  47   base::FilePath Resolve(const base::FilePath& source_root) const;
  48
  49   bool is_null() const { return value_.empty(); }
  50   const std::string& value() const { return value_; }
  51
  52   // Returns true if this path starts with a "//" which indicates a path
  53   // from the source root.
  54   bool is_source_absolute() const {
  55     return value_.size() >= 2 && value_[0] == '/' && value_[1] == '/';
  56   }
  57
  58   // Returns true if this path starts with a single slash which indicates a
  59   // system-absolute path.
  60   bool is_system_absolute() const {
  61     return !is_source_absolute();
  62   }
  63
  64   // Returns a source-absolute path starting with only one slash at the
  65   // beginning (normally source-absolute paths start with two slashes to mark
  66   // them as such). This is normally used when concatenating directories
  67   // together.
  68   //
  69   // This function asserts that the directory is actually source-absolute. The
  70   // return value points into our buffer.
  71   base::StringPiece SourceAbsoluteWithOneSlash() const {
  72     CHECK(is_source_absolute());
  73     return base::StringPiece(&value_[1], value_.size() - 1);
  74   }
  75
  76   void SwapInValue(std::string* v);
  77
  78   bool operator==(const SourceDir& other) const {
  79     return value_ == other.value_;
  80   }
  81   bool operator!=(const SourceDir& other) const {
  82     return !operator==(other);
  83   }
  84   bool operator<(const SourceDir& other) const {
  85     return value_ < other.value_;
  86   }
  87
  88  private:
  89   friend class SourceFile;
  90   std::string value_;
  91
  92   // Copy & assign supported.
  93 };
  94
  95 namespace BASE_HASH_NAMESPACE {
  96
  97 #if defined(COMPILER_GCC)
  98 template<> struct hash<SourceDir> {
  99   std::size_t operator()(const SourceDir& v) const {
 100     hash<std::string> h;
 101     return h(v.value());
 102   }
 103 };
 104 #elif defined(COMPILER_MSVC)
 105 inline size_t hash_value(const SourceDir& v) {
 106   return hash_value(v.value());
 107 }
 108 #endif  // COMPILER...
 109
 110 }  // namespace BASE_HASH_NAMESPACE
 111
 112 #endif  // TOOLS_GN_SOURCE_DIR_H_