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