1  extern void abort (void);
       2  typedef __SIZE_TYPE__ size_t;
       3  extern size_t strlen(const char *);
       4  extern char *strchr(const char *, int);
       5  extern int strcmp(const char *, const char *);
       6  extern int strncmp(const char *, const char *, size_t);
       7  extern int inside_main;
       8  extern const char *p;
       9  
      10  __attribute__ ((used))
      11  char *
      12  my_strstr (const char *s1, const char *s2)
      13  {
      14    const size_t len = strlen (s2);
      15  
      16  #ifdef __OPTIMIZE__
      17    /* If optimizing, we should be called only in the strstr (foo + 2, p)
      18       case.  All other cases should be optimized.  */
      19    if (inside_main)
      20      if (s2 != p || strcmp (s1, "hello world" + 2) != 0)
      21        abort ();
      22  #endif
      23    if (len == 0)
      24      return (char *) s1;
      25    for (s1 = strchr (s1, *s2); s1; s1 = strchr (s1 + 1, *s2))
      26      if (strncmp (s1, s2, len) == 0)
      27        return (char *) s1;
      28    return (char *) 0;
      29  }
      30  
      31  char *
      32  strstr (const char *s1, const char *s2)
      33  {
      34    if (inside_main)
      35      abort ();
      36  
      37    return my_strstr (s1, s2);
      38  }