sdcc/support/regression/tests/bug-895992.c

   1 /* bug-895992.c
   2
   3    Life Range problem with
   4    - uninitialized variable
   5    - loop
   6    - conditional block
   7
   8    LR problem hits all ports, but this test is mcs51 specific
   9  */
  10 #include <testfwk.h>
  11
  12 char p0 = 2;
  13 unsigned short loops;
  14
  15 static void
  16 wait (void)
  17 {
  18   long i, j;
  19
  20   /* just clobber all registers: */
  21   for (i = 0; i < 2; ++i)
  22     for (j = 0; j < 2; ++j)
  23       ;
  24 }
  25
  26 #if !defined(PORT_HOST)
  27 #  pragma disable_warning 84
  28 #endif
  29
  30 static void
  31 testLR (void)
  32 {
  33   unsigned char number;
  34   unsigned char start = 1;
  35   unsigned char i;
  36
  37   do
  38     {
  39       for (i = 1; i > 0 ; i--)
  40         wait ();        /* destroys all registers */
  41       if (start)
  42         {
  43           number = p0;
  44           start = 0;
  45         }
  46       number--;         /* 'number' might be used before initialization     */
  47                         /* the life range of 'number' must be extended to   */
  48                         /* the whole loop _including_ the conditional block */
  49       ++loops;
  50     }
  51   while (number != 0);
  52
  53   ASSERT (loops == p0);
  54 }