gcc/testsuite/gcc.dg/c11-generic-1.c

   1 /* Test C11 _Generic.  Valid uses.  */
   2 /* { dg-do run } */
   3 /* { dg-options "-std=c11 -pedantic-errors" } */
   4
   5 _Noreturn extern void exit (int);
   6 _Noreturn extern void abort (void);
   7
   8 void
   9 check (int n)
  10 {
  11   if (n)
  12     abort ();
  13 }
  14
  15 int
  16 main (void)
  17 {
  18   int n = 0;
  19
  20   check (_Generic (n++, int: 0));
  21   /* _Generic should not evaluate its argument.  */
  22   check (n);
  23
  24   check (_Generic (n, double: n++, default: 0));
  25   check (n);
  26
  27   /* Qualifiers are removed for the purpose of type matching.  */
  28   const int cn = 0;
  29   check (_Generic (cn, int: 0, default: n++));
  30   check (n);
  31   check (_Generic ((const int) n, int: 0, default: n++));
  32   check (n);
  33
  34   /* Arrays decay to pointers.  */
  35   int a[1];
  36   const int ca[1];
  37   check (_Generic (a, int *: 0, const int *: n++));
  38   check (n);
  39   check (_Generic (ca, const int *: 0, int *: n++));
  40   check (n);
  41
  42   /* Functions decay to pointers.  */
  43   extern void f (void);
  44   check (_Generic (f, void (*) (void): 0, default: n++));
  45   check (n);
  46
  47   /* _Noreturn is not part of the function type.  */
  48   check (_Generic (&abort, void (*) (void): 0, default: n++));
  49   check (n);
  50
  51   /* Integer promotions do not occur.  */
  52   short s;
  53   check (_Generic (s, short: 0, int: n++));
  54   check (n);
  55
  56   exit (0);
  57 }