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From: "vincent-gcc at vinc17 dot net" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/95057] missing -Wunused-but-set-variable warning on multiple
 assignments, not all of them used
Date: Mon, 11 May 2020 13:39:40 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95057

--- Comment #4 from Vincent Lef=C3=A8vre <vincent-gcc at vinc17 dot net> ---
OK, so the work (for this warning or a new one) should be done later, but e=
arly
enough not to be affected by optimizations.

One of the goals would be to detect a missing check of a return value of a
function call (typically an error status). For such a typical usage, the sa=
me
variable can be reused for each error status.

  int r;

  r =3D call1 (...);
  check (r);
  /* ... */
  r =3D call2 (...);
  check (r);
  /* ... */
  r =3D call3 (...);
  check (r);

If a check is missing, there should be a warning.=