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From: "msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/104069] -Werror=use-after-free false positive on
 elfutils-0.186
Date: Wed, 19 Jan 2022 20:24:53 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104069

--- Comment #14 from Martin Sebor <msebor at gcc dot gnu.org> ---
Removing the test for !size from the first conditional avoids the warning. =
 I
don't fully understand what the code tries to do but the following avoids i=
t at
-O2 (only):

void *xrealloc (void *ptr, int size)
{
  if (!size)
    size =3D 1;
  void *ret =3D __builtin_realloc (ptr, size);
  if (!ret)
    ret =3D __builtin_realloc (ptr, 1);
  if (!ret) {
    ret =3D __builtin_realloc (ptr, size);
    if (!ret)
      ret =3D __builtin_realloc(ptr, 1);
    if (!ret)
      __builtin_abort ();
  }
  return ret;
}=