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From: "msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/104082] Wdangling-pointer: 2 * false positive ?
Date: Tue, 18 Jan 2022 16:49:29 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104082

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Blocks|                            |104077
             Status|NEW                         |RESOLVED

--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
This form of the warning implements a commonly requested feature missing fr=
om
-Wreturn-local-addr (also included in -Wall): allowing the address of a loc=
al
variable to escape the scope of the function.  Both warnings are issued for
strictly valid code.   See for example pr26671, pr49974, pr54301, pr82520,
pr84544, pr90905 for related requests (the initial implementation is too
simplistic to fully  handle all these but eventually it should).  A case ve=
ry
similar to the one in comment #0 is documented in the manual:

  In the following function the store of the address of the local variable =
x in
the escaped pointer *p also triggers the warning.

  void g (int **p)
  {
    int x =3D 7;
    *p =3D &x;   // warning: storing the address of a local variable in *p
  }

The duplication is (of course) a bug.

Since the warning works as intended and documented (there's no false positi=
ve)
I'm going to resolve this report as invalid.  If you want to request a sepa=
rate
level to control this aspect please open an enhancement request (I'm open to
implementing it).  If you want to remove this level from -Wall, please do t=
he
same (though I don't support that request).


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104077
[Bug 104077] bogus/missing -Wdangling-pointer=