assert.h(c標準庫)

 1 /*my_assert.h*/
 2 #undef my_assert
 3 #ifdef NDEBUG
 4     #define my_assert(test) ((void)0)
 5 #else
 6     void my_fassert(char *);
 7     /*__LINE__是一個十進制數字常，需轉換爲字符串字面量*/
 8     #define STR(x) VAL(x)
 9     #define VAL(x) #x
10     #define my_assert(test) ((test) ? (void) 0 \
11         : my_fassert(__FILE__":"STR(__LINE__)" " #test))
12 #endif

 1 /*my_assert.c*/
 2 #include <stdio.h>
 3 #include <stdlib.h>
 4 
 5 #include "my_assert.h"
 6 
 7 void my_fassert(char *mesg)
 8 {
 9     fputs(mesg, stderr);
10     fputs(" -- assertion failed\n", stderr);
11     abort();
12 }

/*my_t_assert.c*/
#define NDEBUG
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include "my_assert.h"

static int val = 0;

static void field_abort(int sig)
{
    if(val==1){
        puts("fsuccess testing 'my_assert.h'");
        exit(EXIT_SUCCESS);
    }else{
        puts("ffailure testing 'my_assert.h'");
        exit(EXIT_FAILURE);
    }
}

static void dummy()
{
    int i = 0;
    my_assert(i==0);
    my_assert(i==1);
}
/*
 * 在每次包含<assert.h>時，assert宏的行爲由是否認義NDEBUG決定，
 * so此頭文件不具有冪等性
 */
#undef NDEBUG
#include "my_assert.h"

int main(void)
{
    my_assert(signal(SIGABRT, &field_abort) != SIG_ERR);
    dummy();
    my_assert(val==0);
    ++val;
    fputs("sample assertion failure message --\n", stderr);
    my_assert(val==0);
    puts("failure testing 'my_assert.h'");
    return (EXIT_FAILURE);
}