[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2019-02-03 00:00:00         |2021-4-29
             Status|NEW                         |ASSIGNED
      Known to fail|7.3.0, 8.2.0, 9.0           |10.3.0, 11.0, 7.5.0, 8.4.0,
                   |                            |9.3.0
           Assignee|unassigned at gcc dot gnu.org      |msebor at gcc dot gnu.org

--- Comment #6 from Martin Sebor <msebor at gcc dot gnu.org> ---
Reconfirming.  I'm working on a fix.

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch

--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
Patch: https://gcc.gnu.org/pipermail/gcc-patches/2021-May/571120.html

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Martin Sebor <msebor@gcc.gnu.org>:

https://gcc.gnu.org/g:40c64c9ea565230817f08b5e66a30a1c94ec880c

commit r12-1861-g40c64c9ea565230817f08b5e66a30a1c94ec880c
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon Jun 28 15:14:50 2021 -0600

    Regression tests for TREE_NO_WARNING enhancement to warning groups
[PR74765, PR74762].

    PR middle-end/74765 - missing uninitialized warning (parenthesis,
TREE_NO_WARNING abuse)
    PR middle-end/74762 - [9/10/11/12 Regression] missing uninitialized warning
(C++, parenthesized expr, TREE_NO_WARNING)

    gcc/testsuite/ChangeLog:

            * g++.dg/uninit-pr74762.C: New test.
            * g++.dg/warn/uninit-pr74765.C: Same.

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |12.0
      Known to fail|11.0                        |11.1.0
             Status|ASSIGNED                    |RESOLVED

--- Comment #9 from Martin Sebor <msebor at gcc dot gnu.org> ---
Fixed in GCC 12.0.

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu.org

--- Comment #10 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
I don't understand the new code in gimple_set_location:

static inline void
gimple_set_location (gimple *g, location_t location)
{
  /* Copy the no-warning data to the statement location.  */
  copy_warning (location, g->location);
  g->location = location;
}

Typically g->location is UNKNOWN_LOCATION since the GIMPLE statement was just
built so this does:

  copy_warning (location, UNKNOWN_LOCATION);

and finally invokes nowarn_map->remove (location)?

I can fix my particular problem by adding the obvious guard:

static inline void
gimple_set_location (gimple *g, location_t location)
{
  /* Copy the no-warning data to the statement location.  */
  if (g->location != UNKNOWN_LOCATION)
    copy_warning (location, g->location);
  g->location = location;
}

but shouldn't the code query warning-control.cc instead to see if the
no-warning bit is set on g?

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Some comments on the topic are in PR104702

[Bug c++/74765] missing uninitialized warning (parenthesis, TREE_NO_WARNING abuse)

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=74765

--- Comment #12 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Some comments on the topic are in PR104702

Indeed, thanks for the pointer.  I'll probably submit my fixlet though because
the current behavior of gimple_set_location is clearly broken.