1  #undef __USE_STRING_INLINES
       2  #define __USE_STRING_INLINES
       3  #include <string.h>
       4  #include <stdlib.h>
       5  #include <stdio.h>
       6  #include <libc-diag.h>
       7  
       8  int
       9  main (void)
      10  {
      11    const char *a = "abc";
      12    const char *b = a;
      13  
      14    DIAG_PUSH_NEEDS_COMMENT;
      15    /* GCC 9 correctly warns that this call to strspn is useless.  That
      16       is deliberate; this test is verifying that a side effect in an
      17       argument still occurs when the call itself is useless and could
      18       be optimized to return a constant.  */
      19    DIAG_IGNORE_NEEDS_COMMENT (9, "-Wunused-value");
      20    strspn (b++, "");
      21    DIAG_POP_NEEDS_COMMENT;
      22    if (b != a + 1)
      23      return 1;
      24  
      25    return 0;
      26  }