modernc.org/cc@v1.0.1/testdata/gcc-6.3.0/gcc/testsuite/gcc.c-torture/execute/builtins/lib/strspn.c (about)

     1  extern void abort (void);
     2  extern int inside_main;
     3  
     4  __attribute__ ((__noinline__))
     5  __SIZE_TYPE__
     6  strcspn (const char *s1, const char *s2)
     7  {
     8    const char *p, *q;
     9  
    10  #ifdef __OPTIMIZE__
    11    if (inside_main)
    12      abort();
    13  #endif
    14  
    15    for (p = s1; *p; p++)
    16      {
    17        for (q = s2; *q; q++)
    18  	if (*p == *q)
    19  	  goto proceed;
    20        break;
    21  
    22      proceed:;
    23      }
    24    return p - s1;
    25  }