Help needed with wxWidgets3.1 tests compilation error

[Hamish McIntyre-Bhatty]

On 20/01/2022 20:38, Brian Inglis wrote:
> On 2022-01-20 10:10, Hamish McIntyre-Bhatty wrote:
>> I've been having trouble compiling the unit tests for 
>> wxWidgets3.1-3.1.5 on Cygwin. The same tests build just fine on my 
>> Linux Mint 20.3 install, however that is using GCC 9.3.0 instead of 
>> Cygwin's 11.2.0.
>>
>> Attached is the full build log, but I will also point out my ideas 
>> about particular issues here.
>>
>> Note: -Werror=format-security is used in the Makefile. I couldn't find 
>> exactly what this does, but I'm probably looking in the wrong place - 
>> the manpage. Perhaps the following could also be explained by 
>> differences from GCC 9 to 11?
> 
> I check first as in `info GCC Wformat-security` should only care about 
> *printf string variables without using a separate format string.


Ah okay, I guess that doesn't explain the 
-Werror=zero-as-null-pointer-constant errors later. I guess that might 
be a GCC default change.

> 
>> The first is:
>>
>> In file included from /usr/include/unistd.h:4,
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/filefn.h:23, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/utils.h:20, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/cursor.h:75, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/event.h:22, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/evtloop.h:14, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/testprec.h:5, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/allheaders.cpp:433: 
>>
>> /usr/include/sys/unistd.h:23:9: error: redundant redeclaration of ‘int 
>> chmod(const char*, mode_t)’ in same scope [-Werror=redundant-decls]
>>     23 | int     chmod (const char *__path, mode_t __mode);
>>        |         ^~~~~
>> In file included from /usr/include/sys/_default_fcntl.h:211,
>>                   from /usr/include/sys/fcntl.h:3,
>>                   from /usr/include/fcntl.h:12,
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/allheaders.cpp:83: 
>>
>> /usr/include/sys/stat.h:137:9: note: previous declaration of ‘int 
>> chmod(const char*, mode_t)’
>>    137 | int     chmod (const char *__path, mode_t __mode );
>>        |         ^~~~~
>>
>> This doesn't happen on my Linux Mint 20.3 (Ubuntu 20.04) host, so I'm 
>> assuming this is something to do with the standard library?
>>
>> Next is:
>>
>> In file included from /usr/include/unistd.h:4,
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/filefn.h:23, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/utils.h:20, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/cursor.h:75, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/event.h:22, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/include/wx/evtloop.h:14, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/testprec.h:5, 
>>
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/allheaders.cpp:433: 
>>
>> /usr/include/sys/unistd.h:179:9: error: redundant redeclaration of 
>> ‘int pthread_atfork(void (*)(), void (*)(), void (*)())’ in same scope 
>> [-Werror=redundant-decls]
>>    179 | int     pthread_atfork (void (*)(void), void (*)(void), void 
>> (*)(void));
>>        |         ^~~~~~~~~~~~~~
>> In file included from 
>> /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin/bits/gthr-default.h:35, 
>>
>>                   from 
>> /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin/bits/gthr.h:148, 
>>
>>                   from 
>> /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/ext/atomicity.h:35,
>>                   from 
>> /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/bits/ios_base.h:39,
>>                   from 
>> /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/iomanip:40,
>>                   from 
>> /home/Hamis/wxwidgets3.1/wxWidgets3.1-3.1.5-1.x86_64/src/wxWidgets-3.1.5/tests/allheaders.cpp:63: 
>>
>> /usr/include/pthread.h:65:5: note: previous declaration of ‘int 
>> pthread_atfork(void (*)(), void (*)(), void (*)())’
>>     65 | int pthread_atfork (void (*)(void), void (*)(void), void 
>> (*)(void));
>>        |     ^~~~~~~~~~~~~~
>>
>> Ditto.
> 
> Looking at chmod(3p), pthread_atfork(3p), pthread.h(0p) sys_stat.h(0p), 
> unistd.h(0p) those definitions should *NOT* normally be accessible from 
> unistd.h so there should be no conflict, as POSIX specifies what is 
> visible.
> Perhaps they are there for compatibility with older systems like BSD or 
> Solaris and should be suppressed when newer feature macros are defined 
> or specific legacy system macros are not defined?

Perhaps, can anyone else offer any thoughts. I might go ahead and 
compare the headers from my Linux install to those on Cygwin. Perhaps I 
need to define a special macro for Cygwin, I guess that's the easiest 
fix with least possibility of breaking something else?

> 
>> Also of note, is that Cygwin is several times slower at compiling 
>> pretty much everything for me. Does anyone know if this is GCC 9 vs 11 
>> speed, or running Cygwin in Windows 11 in KVM, or something else? I am 
>> running on AMD Ryzen 3000, if that has anything to do with it.
> 
> VM is always slower than native, Windows than Linux, Cygwin than 
> Windows, maybe see if Cygwin under Wine is faster than under Windows in 
> KVM?
> Windows 11 may have more instrumentation than 10 especially if Developer 
> or Insider edition.
> Windows performance profile, desktop/laptop busses, CPU count, MT, 
> speed, memory, SSD/HDD will also have effects.
> 

Oh that's a good idea, I forgot Cygwin finally at least semi works on 
WINE now. I'll see how fast that is. I don't think I want to use that as 
a build environment just in case there's a deficiency in WINE that 
matters during the build, but it might be useful for testing.

Hamish