<winapifamily.h> 和“致命错误 C1012：括号不匹配：缺少 ')'

Question

我正在尝试使用 Microsoft 的 <winapifamily.h> 和 WINAPI_FAMILY_PARTITION 宏。我使用 Visual Studio 工具菜单中的 VS2012 ARM 开发人员提示。当我在下面的代码中使用宏时：

#if defined(CRYPTOPP_WIN32_AVAILABLE) && defined(WINAPI_FAMILY)
# if !(WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP))
#   undef SOCKETS_AVAILABLE
# endif
#endif

然后结果是：

cl.exe /nologo /W4 /D_MBCS /Zi /TP /EHsc /MD /DWINAPI_FAMILY=WINAPI_FAMILY_PHONE_APP /c wait.cpp
wait.cpp
c:\...\config.h(548) : fatal error C1012: unmatched parenthesis : missing ')'
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 11.0
\VC\BIN\x86_ARM\cl.exe"' : return code '0x2'

第 548 行是#if !(WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP))。

删除#if 块会清除不匹配括号的直接错误，但会导致其他地方出现大量与套接字相关的错误。所以我必须能够检测到 Windows Store 和 Windows Phone 应用程序并停用代码路径。

这个不匹配的括号到底在哪里，我该如何解决？

---

这是来自<winapifamily.h> 的相关信息。它来自 Windows Phone Kit。我相当肯定我正在按预期使用它。

/*
 *  Windows APIs can be placed in a partition represented by one of the below bits.   The 
 *  WINAPI_FAMILY value determines which partitions are available to the client code.
 */

#define WINAPI_PARTITION_DESKTOP   0x00000001
#define WINAPI_PARTITION_APP       0x00000002    

/*
 * A family may be defined as the union of multiple families. WINAPI_FAMILY should be set
 * to one of these values.
 */
#define WINAPI_FAMILY_APP          WINAPI_PARTITION_APP
#define WINAPI_FAMILY_DESKTOP_APP  (WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_APP)

/*
 * A constant that specifies which code is available to the program's target runtime platform.
 * By default we use the 'desktop app' family which places no restrictions on the API surface. 
 * To restrict the API surface to just the App API surface, define WINAPI_FAMILY to WINAPI_FAMILY_APP.
 */
#ifndef WINAPI_FAMILY
#define WINAPI_FAMILY WINAPI_FAMILY_DESKTOP_APP
#endif

/* Macro to determine if a partition is enabled */
#define WINAPI_FAMILY_PARTITION(Partition)  ((WINAPI_FAMILY & Partition) == Partition)

/* Macro to determine if only one partition is enabled from a set */
#define WINAPI_FAMILY_ONE_PARTITION(PartitionSet, Partition) ((WINAPI_FAMILY & PartitionSet) == Partition)

/*
 * Macro examples:
 *    The following examples are typical macro usage for enabling/restricting access to header code based
 *    on the target runtime platform. The examples assume a correct setting of the WINAPI_FAMILY macro.
 *
 *      App programs:
 *          Explicitly set WINAPI_FAMILY to WINAPI_PARTITION_APP (cannot access DESKTOP partition)
 *      Desktop programs:
 *          Leave WINAPI_FAMILY set to the default above (currently WINAPI_FAMILY_DESKTOP_APP)
 *
 *      Note: Other families and partitions may be added in the future.
 *
 *
 * The WINAPI_FAMILY_PARTITION macro:
 *    Code-block is available to programs that have access to specified partition.
 *
 *      Example: Available to App and Desktop programs
 *          #if WINAPI_FAMILY_PARTITION( WINAPI_PARTITION_APP )
 *
 *      Example: Available to Desktop programs
 *          #if WINAPI_FAMILY_PARTITION( WINAPI_PARTITION_DESKTOP )
 *
 *
 * The WINAPI_FAMILY_ONE_PARTITION macro:
 *    Code-block is available to programs that have access to specified parition, but not others in the partition set.
 *
 *      Example: Available only to App programs
 *          #if WINAPI_FAMILY_ONE_PARTITION( WINAPI_FAMILY, WINAPI_PARTITION_APP )
 *
 *      Example: Available only to Desktop programs
 *          #if WINAPI_FAMILY_ONE_PARTITION( WINAPI_FAMILY, WINAPI_PARTITION_DESKTOP )
 *
 *      Example: Available to App, but not Desktop programs
 *          #if WINAPI_FAMILY_ONE_PARTITION( WINAPI_FAMILY_DESKTOP_APP, WINAPI_PARTITION_APP )
 */

Answer 1

<winapifamily.h> 默认不包括在内。如果您不包含它（最好通过#include，但/FI 也是一个选项），那么预处理器将用0 替换（未定义的）WINAPI_FAMILY_PARTITION 和WINAPI_PARTITION_DESKTOP。这意味着

# if !(WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP))

等价于

# if !(0(0))

这不是一个有效的预处理表达式。可以通过指示编译器/预处理器发出诊断信息来发现此类错误。 MSVC 有C4668。这是 4 级警告，但默认关闭。所以你必须用/w44668 启用它。 GCC 有-Wundef。