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