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Re: [Consult] g++: About "-Wunused-variable" for constant variable initialized by function
- From: Chen Gang <gang dot chen dot 5i5j at gmail dot com>
- To: Jason Merrill <jason at redhat dot com>, Jeff Law <law at redhat dot com>, nathan at codesourcery dot com
- Cc: gcc at gcc dot gnu dot org, Peter Maydell <peter dot maydell at linaro dot org>
- Date: Wed, 22 Oct 2014 09:46:03 +0800
- Subject: Re: [Consult] g++: About "-Wunused-variable" for constant variable initialized by function
- Authentication-results: sourceware.org; auth=none
- References: <543A910F dot 7060301 at gmail dot com> <543BAF23 dot 6080808 at redhat dot com> <543BD122 dot 5010201 at gmail dot com> <543E4769 dot 30006 at gmail dot com>
On 10/15/14 18:07, Chen Gang wrote:
> On 10/13/14 21:18, Chen Gang wrote:
>> On 10/13/14 18:53, Jason Merrill wrote:
>>> On 10/12/2014 10:32 AM, Chen Gang wrote:
>>>> [root@localhost qemu_cc]# cat test.cc
>>>> const char n() { return 1; }
>>>> const char c = n();
>>>> [root@localhost qemu_cc]# /usr/local/bin/g++ -Wall -O0 -c -o test.o test.cc
>>>> [root@localhost qemu_cc]# /usr/local/bin/g++ -Wall -O2 -c -o test.o test.cc
>>>> test.cc:2:12: warning: 'c' defined but not used [-Wunused-variable]
>>>> const char c = n();
>>>> ^
>>>
>>> The warning is correct (and new). Please submit bug reports via the website; see https://gcc.gnu.org/bugs/
>>>
Aftr trying, I can not make a new account for gcc bugzilla.
- Before file a bug, it is mandatory to have an acount.
- I try to register a new account on the website, it said that need
send mail to overseers@gcc.gnu.org.
- I sent related mail to overseers@gcc.gnu.org, but get no response.
Need I wait for some days? or could any member help to file this bug to
gcc bugzilla?
And whether it is OK or not, I shall try to analyze this issue directly,
I should try to finish it within 2014-10-31 (although I am really not
quite sure about it).
Thanks.
>
> Thank Jason Merrill, again. At present, I have got enough confirmation
> from you and other members (excuse me, I am not quite familiar with C++,
> for me, it is a complex language, so need several members confirmation).
>
> And if no additional reply within this week, I shall submit bug reports,
> and try to fix it within this month (although I am really not quite
> sure).
>
> I am not quite familiar with C++, so if any members worry about me: feel
> that I am not quite suitable to report bug and fix it, please let me
> know within this week.
>
> Thanks.
>
>>
>> OK, thanks. After finish this consult, I shall report bugs, and shall
>> try to fix it (I got it from Qemu which in my current focus border).
>> Hope I can finish within this month.
>>
>> And one another consult: if the constant variable is defined in header
>> file, and never be used, need our g++ still report warning about
>> [-Wunused-variable] too (for me, I guess, not)?
>>
>>
>> Thanks.
>>
>
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed