C 宏上的警告太多

Question

我正在尝试一种在我的代码上标记警告的方法，但我犯了一些错误，无法理解在哪里。我的编译器每次使用这个宏时都会给我太多警告：

#define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__);

#define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);

使用示例：

MPL_ERROR_MESSAGE("Test %d", 2);

 

    In file included from ../trunk/mpl_position.h:5:0,
                     from ../trunk/mpl_baseenvironment.h:6,
                     from ../trunk/mpl_baseenvironment.cpp:1:
    ../trunk/mpl_baseenvironment.cpp: In member function ‘int MPL_BaseEnvironment::getEnemyRobotAt(MPL_Position&, int)’:
    ../trunk/mpl_utils.h:7:167: warning: too many arguments for format [-Wformat-extra-args]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_baseenvironment.cpp:28:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("(invalid value) not in [0,%d) ", i_ER, qlMPLP_enemyRobot__.size());
             ^
    ../trunk/mpl_baseenvironment.cpp: In member function ‘int MPL_BaseEnvironment::deleteEnemyRobotAt(int)’:
    ../trunk/mpl_utils.h:7:167: warning: too many arguments for format [-Wformat-extra-args]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_baseenvironment.cpp:45:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("(invalid value) not in [0,%d) ", i_ER, qlMPLP_enemyRobot__.size());
             ^
    ../trunk/mpl_baseenvironment.cpp: In member function ‘int MPL_BaseEnvironment::getMovableObstacleAt(MPL_Position&, int)’:
    ../trunk/mpl_utils.h:7:167: warning: too many arguments for format [-Wformat-extra-args]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__

编辑：更新警告列表


    ../trunk/mpl_gridenvironment.h: In member function ‘long int MPL_GridEnvironment::arrayIndex(MPL_Position&)’:
    ../trunk/mpl_utils.h:7:167: warning: unknown conversion type character ‘,’ in format [-Wformat=]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_gridenvironment.h:253:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("Invalid Position at (%l, %l, %l)", x, y, z);
             ^
    ../trunk/mpl_utils.h:7:167: warning: unknown conversion type character ‘,’ in format [-Wformat=]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_gridenvironment.h:253:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("Invalid Position at (%l, %l, %l)", x, y, z);
             ^
    ../trunk/mpl_utils.h:7:167: warning: unknown conversion type character ‘)’ in format [-Wformat=]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_gridenvironment.h:253:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("Invalid Position at (%l, %l, %l)", x, y, z);
             ^
    ../trunk/mpl_utils.h:7:167: warning: too many arguments for format [-Wformat-extra-args]
     #define MPL_ERROR_MESSAGE2(output, fmt, ...) fprintf(output, ("\n[ERROR][%s:%d( %s )]\n---  " fmt "  ---\n\n"), __FILE__, __LINE__, __PRETTY_FUNCTION__, ##__VA_ARGS__); //error message
                                                                                                                                                                           ^
    ../trunk/mpl_utils.h:9:37: note: in expansion of macro ‘MPL_ERROR_MESSAGE2’
     #define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__);
                                         ^
    ../trunk/mpl_gridenvironment.h:253:9: note: in expansion of macro ‘MPL_ERROR_MESSAGE’
             MPL_ERROR_MESSAGE("Invalid Position at (%l, %l, %l)", x, y, z);

编辑 2：按照要求，触发警告的地方之一：

inline long arrayIndex(MPL_Position& sMPLP_p)
{
    long x, y, z;
    x = MPL_ROUND_INT((d_delta*sMPLP_p.getX())/d_sizeX__);
    y = MPL_ROUND_INT((d_delta*sMPLP_p.getY())/d_sizeY__);
    z = MPL_ROUND_INT((d_delta*sMPLP_p.getZ())/d_sizeZ__);

    if( (x>=0) && (x<n_sizeX__) && (y>=0) && (y<n_sizeY__) && (z>=0) && (z<n_sizeZ__) ){ //isValidPosition(...)
        return( (x*n_sizeY__ + y)*n_sizeZ__ + z );
    }

    MPL_ERROR_MESSAGE("Invalid Position at (%l, %l, %l)", x, y, z);

    MPL_GE_InvalidPosition(sMPLP_p);

    return( -1 );
}

(n_size?__ 和 d_size?__ 是 class 属性；不要费心去理解那个……:P )

Answer 1

关于您编辑中列出的警告：

unknown conversion type character ‘,’ in format

这个

... "Invalid Position at (%l, %l, %l)", ...

应该是

... "Invalid Position at (%ld, %ld, %ld)", ...

你通过了long signed int。 signed int 的 转换说明符 是 d。传递 long 时，在其前面加上 长度修饰符 l.

并且，虽然无关，但请从宏中删除尾随 ;。

Answer 2

我发现了

之间的区别

#define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, ##__VA_ARGS__)

和

#define MPL_ERROR_MESSAGE(fmt, ...) MPL_ERROR_MESSAGE2(stderr, fmt, __VA_ARGS__)

不带参数使用时，如

MPL_ERROR_MESSAGE("Just a message! Hi!");

第一个导致

MPL_ERROR_MESSAGE2(stderr, "Just a message! Hi!", __VA_ARGS__)

而第二个导致

MPL_ERROR_MESSAGE2(stderr, "Just a message! Hi!", __VA_ARGS__, )

这是错误的。大错特错。只是不要编译，因为 MPL_ERROR_MESSAGE2 没想到最后一个逗号。你知道为什么会这样吗？我应该 post 一个新问题吗？

C 宏上的警告太多

Too many warnings on a C macro

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macros

gcc

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