__wine_uuidof causing a wall of "warning: returning reference to temporary" on g++

[Ilya Konstantinov]

Hi Jacek,

I just realized what was the difference in my case.
I was including the system headers manually with -I/usr/include/wine/windows
as opposed to -isystem/usr/include/wine/windows (as winegcc/wineg++ does
it).

gcc suppresses warnings in system headers (when using -isystem):
http://gcc.gnu.org/onlinedocs/cpp/System-Headers.html

On Tue, Jul 31, 2012 at 11:38 AM, Jacek Caban <jacek at codeweavers.com> wrote:

>  On 07/30/12 13:13, Ilya Konstantinov wrote:
>
>  On Sun, Jul 29, 2012 at 9:47 PM, Jacek Caban <jacek at codeweavers.com>wrote:
>
>>  Upon first attempts to compile, I've received a wall of "warning:
>>> returning reference to temporary" on Wine's headers from g++.
>>> All of those seem to stem from guidgen.h definition of __wine_uuidof /
>>> __CRT_UUID_DECL for C++.
>>>
>>
>
>> I don't see these warnings here. Also Wine has the same code for __uuidof
>> as mingw-w64, which is much more widely used with g++ (Wine is mostly
>> tested on C), and I never heard about such problem. Do you have any idea
>> about what could be different in your setup? What's your g++ version?
>
>
>  I'm using gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) to build my
> Winelib app.
>
>  As to the difference from mingw-w64, I see different code in there:
>
> http://mingw-w64.svn.sourceforge.net/viewvc/mingw-w64?view=revision&revision=4279
>
>  The idea is that if matches closer to the meaning of __uuidof, which
>> should return a reference to constant IID structure.
>
>
>  Understood.
>
>
>> I'd expect compiler to be smart enough to produce same code without the
>> reference anyway (after all it's an inline function), but still being more
>> explicit would be nice. Could you please test if the attached patch fixes
>> the problem for you?
>
>
>  Yep, it does.
>
>
> I've tested it more and sent a patch.
>
> Jacek
>
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