Add shared macros for stringizing and converting ANSI string constants...

base/preprocessor_util.h

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// This file defines utility preprocessor macros.
+
+#ifndef BASE_PREPROCESSOR_UTIL_H_
+#define BASE_PREPROCESSOR_UTIL_H_
+#pragma once
+
+// These are not very useful; they do not expand defined symbols if
+// called directly. Use their counterparts without the _NO_EXPANSION
+// suffix, below.
+#define STRINGIZE_NO_EXPANSION(x) #x
+#define LSTRINGIZE_NO_EXPANSION(x) L ## #x

[Evan Martin, 2010/11/17 23:37:29]

We have deprecated wide strings.  If you really need these for some
Windows-specific code, can you wrap them in an #if defined(OS_WIN) block so that
people aren't tempted to use them elsewhere?

+#define TO_L_STRING_NO_EXPANSION(x) L ## x
+
+// Use these to quote the provided parameter, first expanding it if it
+// is a preprocessor symbol. The L version quotes it as a wide string,
+// the non-L version as an ANSI string.
+//
+// For example, if:
+//   #define A FOO
+//   #define B(x) myobj->FunctionCall(x)
+//
+// Then:
+//   STRINGIZE(A) produces "FOO"
+//   LSTRINGIZE(B(y)) produces L"myobj->FunctionCall(y)"
+#define STRINGIZE(x) STRINGIZE_NO_EXPANSION(x)
+#define LSTRINGIZE(x) LSTRINGIZE_NO_EXPANSION(x)
+
+// Adds an L in front of an existing ANSI string constant (after
+// expanding symbols). Does not do any quoting.
+//
+// For example, if:
+//   #define C "foo"
+//
+// Then:
+//   TO_L_STRING(C) produces L"foo"
+#define TO_L_STRING(x) TO_L_STRING_NO_EXPANSION(x)
+
+#endif  // BASE_PREPROCESSOR_UTIL_H_