Attempt at improved OS macros

build/build_config.h

 // Copyright (c) 2012 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 adds defines about the platform we're currently building on.
 //  Operating System:
 //    OS_WIN / OS_MACOSX / OS_LINUX / OS_POSIX (MACOSX or LINUX)
 //  Compiler:
 //    COMPILER_MSVC / COMPILER_GCC
 //  Processor:
 //    ARCH_CPU_X86 / ARCH_CPU_X86_64 / ARCH_CPU_X86_FAMILY (X86 or X86_64)
 //    ARCH_CPU_32_BITS / ARCH_CPU_64_BITS
 
 #ifndef BUILD_BUILD_CONFIG_H_
 #define BUILD_BUILD_CONFIG_H_
 
 #if defined(__APPLE__)
 #include <TargetConditionals.h>
 #endif
 
 // A set of macros to use for platform detection.
 #if defined(__APPLE__)
 #define OS_MACOSX 1
+#define OS_IS_ENABLED__WIN +

[Ryan Sleevi, 2013/03/19 21:55:13]

BUG: s/__WIN/__MAC

 #if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
 #define OS_IOS 1
+#define OS_IS_ENABLED__IOS +
 #endif  // defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE
 #elif defined(ANDROID)
 #define OS_ANDROID 1
+#define OS_IS_ENABLED__ANDROID +
 #elif defined(__native_client__)
 #define OS_NACL 1
+#define OS_IS_ENABLED__NACL +
 #elif defined(__linux__)
 #define OS_LINUX 1
+#define OS_IS_ENABLED__LINUX +
 // Use TOOLKIT_GTK on linux if TOOLKIT_VIEWS isn't defined.
 #if !defined(TOOLKIT_VIEWS)
 #define TOOLKIT_GTK
 #endif
 #elif defined(_WIN32)
 #define OS_WIN 1
 #define TOOLKIT_VIEWS 1
+#define OS_IS_ENABLED__WIN +
 #elif defined(__FreeBSD__)
 #define OS_FREEBSD 1
+#define OS_IS_ENABLED__FREEBSD +
 #define TOOLKIT_GTK
 #elif defined(__OpenBSD__)
 #define OS_OPENBSD 1
+#define OS_IS_ENABLED__OPENBSD +
 #define TOOLKIT_GTK
 #elif defined(__sun)
 #define OS_SOLARIS 1
+#define OS_IS_ENABLED__SOLARIS +
 #define TOOLKIT_GTK
 #else
 #error Please add support for your platform in build/build_config.h
 #endif
 
+#define OS(x) ((1 OS_IS_ENABLED__##x 1) == 2)
+
 #if defined(USE_OPENSSL) && defined(USE_NSS)
 #error Cannot use both OpenSSL and NSS
 #endif
 
 // For access to standard BSD features, use OS_BSD instead of a
 // more specific macro.
 #if defined(OS_FREEBSD) || defined(OS_OPENBSD)
 #define OS_BSD 1
 #endif
 
@@ skipping 82 matching lines @@
 #if defined(OS_ANDROID)
 // The compiler thinks std::string::const_iterator and "const char*" are
 // equivalent types.
 #define STD_STRING_ITERATOR_IS_CHAR_POINTER
 // The compiler thinks base::string16::const_iterator and "char16*" are
 // equivalent types.
 #define BASE_STRING16_ITERATOR_IS_CHAR16_POINTER
 #endif
 
 #endif  // BUILD_BUILD_CONFIG_H_