实现assert函数

http://vincent.blog.chinaunix.net
想不到今天实现assert函数也搞了我这么久。。。郁闷。。。

file: assertx.h

/*
 * author: [e-mail]
 * history:
 * initial @ 2011-08-23
 */

#ifndef _ASSERTX_H_
#define _ASSERTX_H_

#include <stdio.h>
#include <stdarg.h>

#define OUTPUT_WHERE OUTPUT_SCREEN

/* where to output */
#define OUTPUT_SCREEN    1
#define OUTPUT_FILE        2

/* halt on */
#ifndef unreachable
#define unreachable() do {} while (1)
#endif

/* Microsoft VC TOOLS VERSION DEFINITION
 * MS VC++ 10.0 _MSC_VER = 1600
 * MS VC++ 9.0 _MSC_VER = 1500
 * MS VC++ 8.0 _MSC_VER = 1400
 * MS VC++ 7.1 _MSC_VER = 1310
 * MS VC++ 7.0 _MSC_VER = 1300
 * MS VC++ 6.0 _MSC_VER = 1200
 * MS VC++ 5.0 _MSC_VER = 1100
 */

#if defined(WIN32)&&(_MSC_VER < 1300)

    #define __func__ "?"
    /* you need define outputx itself under VC6 */
    extern void outputx(const char* fmt,...);
    #if OUTPUT_WHERE!=OUTPUT_SCREEN && OUTPUT_WHERE!=OUTPUT_FILE
    /* no output */
    #define outputx(fmt,...)
    #endif

#else

    #define __func__ __FUNCTION__
    /* output to screen */
    #if OUTPUT_WHERE==OUTPUT_SCREEN
    #define outputx(fmt,...) \
    do { \
        printf(##fmt, ##__VA_ARGS__); \
    }while(0)
    /* output to file */
    #elif OUTPUT_WHERE==OUTPUT_FILE
    extern void outputx(const char* fmt,...);
    #else
    /* no output */
    #define outputx(fmt,...)
    #endif

#endif

/* go on the next step after assert(0) */
#define assertx_goon(expr) \
do { \
    if (!(expr)) { \
        outputx("Assertion failed! %s, %s, %s, line %d\n", \
                        #expr, __FILE__, __func__, __LINE__); \
    } \
}while(0)

/* halt after assert(0) */
#define assertx_halt(expr) \
do { \
    if (!(expr)) { \
    outputx("Assertion failed! %s, %s, %s, line %d\n", \
        #expr, __FILE__, __func__, __LINE__); \
    unreachable();\
    } \
}while(0)


#endif

file: main.c

/*
 * author: [e-mail]
 * history:
 * initial @ 2011-08-23
 */

#include "assertx.h"

#ifdef WIN32
#define vsnprintf _vsnprintf
#endif

#define MAX_OUTPUT 100

void outputx(const char* fmt,...)
{
    int ret;
    char buf[MAX_OUTPUT];
    va_list args;
    va_start(args, fmt);
    ret = vsnprintf(buf, sizeof(buf), fmt, args);
    buf[MAX_OUTPUT-1]=0;
    if(ret<0){
        printf("warning: output has been truncated!");
    }
    printf ("%s", buf);
    va_end(args);
}

int main(int argc, char* argv[])
{
    assertx_goon(0);
    assertx_halt(0);
    return 0;
}

附件： assertx.rar