gcc/testsuite/gcc.dg/Wuse-after-free.c

   1 /* PR middle-end/104069 - -Werror=use-after-free false positive on
   2    elfutils-0.186
   3    { dg-do compile }
   4    { dg-options "-Wall" } */
   5
   6 typedef __SIZE_TYPE__ size_t;
   7
   8 extern void* realloc (void *, size_t);
   9
  10 void* __libdw_unzstd (size_t todo)
  11 {
  12   void *sb = 0;
  13
  14   for ( ; ; )
  15     {
  16       // Ran only once.
  17       if (!sb)
  18         {
  19           char *b = realloc (sb, todo);
  20           if (!b)
  21             break;
  22
  23           sb = b;
  24         }
  25
  26       todo -= 1;
  27       if (todo == 0)
  28         break;
  29     }
  30
  31   // Shrink buffer: leave only one byte for simplicity.
  32   char *b = realloc (sb, 1);
  33   if (b)
  34     sb = b;
  35   else
  36     {
  37       // Realloc failed mysteriously, leave 'sb' untouched.
  38     }
  39
  40   return sb;        // { dg-bogus "-Wuse-after-free" }
  41 }