tools/gn/source_file.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_FILE_H_
   6 #define TOOLS_GN_SOURCE_FILE_H_
   7
   8 #include <algorithm>
   9 #include <string>
  10
  11 #include "base/containers/hash_tables.h"
  12 #include "base/files/file_path.h"
  13 #include "base/logging.h"
  14 #include "base/strings/string_piece.h"
  15
  16 class SourceDir;
  17
  18 // Represents a file within the source tree. Always begins in a slash, never
  19 // ends in one.
  20 class SourceFile {
  21  public:
  22   enum SwapIn { SWAP_IN };
  23
  24   SourceFile();
  25
  26   // Takes a known absolute source file. Always begins in a slash.
  27   explicit SourceFile(const base::StringPiece& p);
  28
  29   // Constructs from the given string by swapping in the contents of the given
  30   // value. The value will be the empty string after this call.
  31   SourceFile(SwapIn, std::string* value);
  32
  33   ~SourceFile();
  34
  35   bool is_null() const { return value_.empty(); }
  36   const std::string& value() const { return value_; }
  37
  38   // Returns everything after the last slash.
  39   std::string GetName() const;
  40   SourceDir GetDir() const;
  41
  42   // Resolves this source file relative to some given source root. Returns
  43   // an empty file path on error.
  44   base::FilePath Resolve(const base::FilePath& source_root) const;
  45
  46   // Returns true if this file starts with a "//" which indicates a path
  47   // from the source root.
  48   bool is_source_absolute() const {
  49     return value_.size() >= 2 && value_[0] == '/' && value_[1] == '/';
  50   }
  51
  52   // Returns true if this file starts with a single slash which indicates a
  53   // system-absolute path.
  54   bool is_system_absolute() const {
  55     return !is_source_absolute();
  56   }
  57
  58   // Returns a source-absolute path starting with only one slash at the
  59   // beginning (normally source-absolute paths start with two slashes to mark
  60   // them as such). This is normally used when concatenating names together.
  61   //
  62   // This function asserts that the file is actually source-absolute. The
  63   // return value points into our buffer.
  64   base::StringPiece SourceAbsoluteWithOneSlash() const {
  65     CHECK(is_source_absolute());
  66     return base::StringPiece(&value_[1], value_.size() - 1);
  67   }
  68
  69   bool operator==(const SourceFile& other) const {
  70     return value_ == other.value_;
  71   }
  72   bool operator!=(const SourceFile& other) const {
  73     return !operator==(other);
  74   }
  75   bool operator<(const SourceFile& other) const {
  76     return value_ < other.value_;
  77   }
  78
  79   void swap(SourceFile& other) {
  80     value_.swap(other.value_);
  81   }
  82
  83  private:
  84   friend class SourceDir;
  85
  86   std::string value_;
  87
  88   // Copy & assign supported.
  89 };
  90
  91 namespace BASE_HASH_NAMESPACE {
  92
  93 template<> struct hash<SourceFile> {
  94   std::size_t operator()(const SourceFile& v) const {
  95     hash<std::string> h;
  96     return h(v.value());
  97   }
  98 };
  99
 100 }  // namespace BASE_HASH_NAMESPACE
 101
 102 inline void swap(SourceFile& lhs, SourceFile& rhs) {
 103   lhs.swap(rhs);
 104 }
 105
 106 #endif  // TOOLS_GN_SOURCE_FILE_H_