[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[chengniansun at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

Chengnian Sun <chengniansun at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |chengniansun at gmail dot com

--- Comment #4 from Chengnian Sun <chengniansun at gmail dot com> ---
May I ask what is the design rational of not warning unused static const
variables?  

I saw Clang has a different strategy, and it even has a type of warning --
[-Wunused-const-variable]

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Well, clang strategy seems to be not to bother with false positives and always
prefer warning over not warning on anything, so usually the clang output is
just completely unreadable because among the tons of false positives it is hard
to find actual real code problems.  GCC strategy is to find some ballance
between false positive warnings and missed warnings.

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[mikpelinux at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

--- Comment #6 from Mikael Pettersson <mikpelinux at gmail dot com> ---
(In reply to Chengnian Sun from comment #4)
> May I ask what is the design rational of not warning unused static const
> variables?  

See PR28901.  There are cases of unused static const where the warning isn't
wanted, and so far the decision has been to favour those over the cases where
the warning _is_ wanted and would have detected real bugs.  Sigh.

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[chengniansun at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

--- Comment #7 from Chengnian Sun <chengniansun at gmail dot com> ---
Thanks, Jakub and Mikael. 

I see it now. IMHO, it might be worthy to add a flag -Wunused-const-variable
similar to Clang, which is not included either -Wall or -Wextra. Therefore the
end user can decide whether to enable this warning based on their specific
scenario. I think it is better than the current case that people who need this
warning support cannot get it.

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Chengnian Sun from comment #7)
> Thanks, Jakub and Mikael. 
> 
> I see it now. IMHO, it might be worthy to add a flag -Wunused-const-variable
> similar to Clang, which is not included either -Wall or -Wextra. Therefore
> the end user can decide whether to enable this warning based on their
> specific scenario. I think it is better than the current case that people
> who need this warning support cannot get it.

Yeah, I guess that is a possibility.

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[tromey at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

Tom Tromey <tromey at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |tromey at gcc dot gnu.org

--- Comment #9 from Tom Tromey <tromey at gcc dot gnu.org> ---
I think my recent comments here apply:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28901#c5
Please consider reopening this PR.

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2003-11-13 19:42 -------
Fixed in GCC 3.4.

-- 
           What    |Removed                     |Added
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             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-11-13 19:40 -------
Subject: Bug 13029

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	mmitchel@gcc.gnu.org	2003-11-13 19:40:20

Modified files:
	gcc            : ChangeLog toplev.c 
	gcc/testsuite  : ChangeLog 
	gcc/testsuite/gcc.dg: unused-4.c 

Log message:
	PR c/13029
	* toplev.c (check_global_declarations): Do not warn about unused
	static consts.
	
	PR c/13029
	* gcc.dg/unused-4.c: Update.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.1735&r2=2.1736
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/toplev.c.diff?cvsroot=gcc&r1=1.843&r2=1.844
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.3189&r2=1.3190
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/unused-4.c.diff?cvsroot=gcc&r1=1.1&r2=1.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029

[Bug c/13029] [3.4 Regression] static consts and -Wunused-variable

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-11-12 22:10 -------
Confirmed.

Broken on the mainline: Search converges between 2002-03-31-trunk (#71) and 2002-04-07-
trunk (#72).

Fixed in the 3.3 branch: Search converges between 2003-05-05-3.3 (#119) and 2003-05-06-3.3 
(#120).
Not fixed again on the mainline.

This patch was not applied to the mainline which fixes it: <http://gcc.gnu.org/ml/gcc-patches/
2003-05/msg00468.html>.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mark at codesourcery dot com
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |diagnostic, patch
   Last reconfirmed|0000-00-00 00:00:00         |2003-11-12 22:10:12
               date|                            |
            Summary|static consts and -Wunused- |[3.4 Regression] static
                   |variable                    |consts and -Wunused-variable
   Target Milestone|---                         |3.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13029