Re: ‘OUTPUT_DRAWMODE_CONTRAST’ defined but not used

[Stephan Bergmann]

On 08/26/2015 03:43 PM, Michael Stahl wrote:
> On 26.08.2015 15:34, Stephan Bergmann wrote:
>> On 08/25/2015 05:59 PM, Khaled Hosny wrote:
>>> On Tue, Aug 25, 2015 at 05:54:32PM +0200, Stephan Bergmann wrote:
>>>> On 08/25/2015 05:30 PM, Khaled Hosny wrote:
>>>>> In may build I see this warning a lot:
>>>>> In file included from cui/source/tabpages/textattr.cxx:37:0:
>>>>> include/svx/dlgutil.hxx:37:28: warning: ‘OUTPUT_DRAWMODE_CONTRAST’ defined but not used [-Wunused-variable]
>>>>>    static const DrawModeFlags OUTPUT_DRAWMODE_CONTRAST = DrawModeFlags::SettingsLine | DrawModeFlags::SettingsFill | DrawModeFlags::SettingsText | DrawModeFlags::SettingsGradient;
>>>>>
>>>>> I’m guessing it is caused by the static in the declaration since
>>>>> OUTPUT_DRAWMODE_CONTRAST seems to be used somewhere.
>>>>
>>>> Compilers are free to not emit storage for that per-copilation-unit const
>>>> variable (what an oxymoron), and most compilers are apparently smart enough
>>>> to not emit a -Wunused-variable in such a case (or else the build should
>>>> break for many developers, assuming developers routinely configure
>>>> --enable-werror).  Yours just isn't
>>>
>>> I wouldn’t be able to finish any build if I turned this on, I get even
>>> more warnings about deprecated std::auto_ptr which seems to be used in
>>> boost’s get_pointer.hpp.
>>
>> These would go away (or at least not cause an error) if you use
>> --without-system-boost, IIUC.
>
> that's not the case for me.  but it's odd that these warnings aren't
> converted to errors with --enable-werror - they remain warnings.

Yeah, I see lots of such auto_ptr-related warnings when building with 
GCC (none with Clang), but never as errors, so assumed their 
non-errorness was due to the various

   +# pragma GCC diagnostic ignored "-Wdeprecated-declarations"

in external/boost/boost.wdeprecated-auto_ptr.patch.0, finding no other 
obvious place in the LO sources that cause them to be demoted from error 
to mere warning.

>>>> ---some dated GCC?
>>>
>>> That is GCC 5.2.0, so I guess a rather too new one.
>>
>> Odd, neither the Fedora 22 GCC 5.1.1 nor a recent trunk build (towards
>> GCC 6) triggers that warning for me when building cui.
>
> i'm getting loads of these on Fedora 22.

"these" being auto_ptr-related warnings, or the OUTPUT_DRAWMODE_CONTRAST 
-Wunused-variable that my "that warning" references?