base/stringize_macros.h

   1 // Copyright (c) 2010 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 // This file defines preprocessor macros for stringizing preprocessor
   6 // symbols (or their output) and manipulating preprocessor symbols
   7 // that define strings.
   8
   9 #ifndef BASE_STRINGIZE_MACROS_H_
  10 #define BASE_STRINGIZE_MACROS_H_
  11
  12 #include "build/build_config.h"
  13
  14 // This is not very useful as it does not expand defined symbols if
  15 // called directly. Use its counterpart without the _NO_EXPANSION
  16 // suffix, below.
  17 #define STRINGIZE_NO_EXPANSION(x) #x
  18
  19 // Use this to quote the provided parameter, first expanding it if it
  20 // is a preprocessor symbol.
  21 //
  22 // For example, if:
  23 //   #define A FOO
  24 //   #define B(x) myobj->FunctionCall(x)
  25 //
  26 // Then:
  27 //   STRINGIZE(A) produces "FOO"
  28 //   STRINGIZE(B(y)) produces "myobj->FunctionCall(y)"
  29 #define STRINGIZE(x) STRINGIZE_NO_EXPANSION(x)
  30
  31 // The following are defined only on Windows (for use when interacting
  32 // with Windows APIs) as wide strings are otherwise deprecated.
  33 #if defined(OS_WIN)
  34
  35 // Second-level utility macros to let us expand symbols.
  36 #define LSTRINGIZE_NO_EXPANSION(x) L ## #x
  37 #define TO_L_STRING_NO_EXPANSION(x) L ## x
  38
  39 // L version of STRINGIZE(). For examples above,
  40 //   LSTRINGIZE(A) produces L"FOO"
  41 //   LSTRINGIZE(B(y)) produces L"myobj->FunctionCall(y)"
  42 #define LSTRINGIZE(x) LSTRINGIZE_NO_EXPANSION(x)
  43
  44 // Adds an L in front of an existing ASCII string constant (after
  45 // expanding symbols). Does not do any quoting.
  46 //
  47 // For example, if:
  48 //   #define C "foo"
  49 //
  50 // Then:
  51 //   TO_L_STRING(C) produces L"foo"
  52 #define TO_L_STRING(x) TO_L_STRING_NO_EXPANSION(x)
  53
  54 #endif  // defined(OS_WIN)
  55
  56 #endif  // BASE_STRINGIZE_MACROS_H_