gcc/testsuite/gcc.c-torture/execute/pr17377.c

   1 /* PR target/17377
   2    Bug in code emitted by "return" pattern on CRIS: missing pop of
   3    forced return address on stack.  */
   4 /* { dg-require-effective-target return_address } */
   5 int calls = 0;
   6
   7 void *f (int) __attribute__ ((__noinline__));
   8 void *
   9 f (int i)
  10 {
  11   /* The code does a little brittle song and dance to trig the "return"
  12      pattern instead of the function epilogue.  This must still be a
  13      leaf function for the bug to be exposed.  */
  14
  15   if (calls++ == 0)
  16     return __builtin_return_address (0);
  17
  18   switch (i)
  19     {
  20     case 1:
  21       return f;
  22     case 0:
  23       return __builtin_return_address (0);
  24     }
  25   return 0;
  26 }
  27
  28 int x;
  29
  30 void *y (int i) __attribute__ ((__noinline__,__noclone__));
  31 void *
  32 y (int i)
  33 {
  34   x = 0;
  35
  36   /* This must not be a sibling call: the return address must appear
  37      constant for different calls to this function.  Postincrementing x
  38      catches otherwise unidentified multiple returns (e.g. through the
  39      return-address register and then this epilogue popping the address
  40      stored on stack in "f").  */
  41   return (char *) f (i) + x++;
  42 }
  43
  44 int
  45 main (void)
  46 {
  47   void *v = y (4);
  48   if (y (1) != f
  49       /* Can't reasonably check the validity of the return address
  50          above, but it's not that important: the test-case will probably
  51          crash on the first call to f with the bug present, or it will
  52          run wild including returning early (in y or here), so we also
  53          try and check the number of calls.  */
  54       || y (0) != v
  55       || y (3) != 0
  56       || y (-1) != 0
  57       || calls != 5)
  58     abort ();
  59   exit (0);
  60 }