Re: Current master doesn't build on Win10 (nor does emacs-28)

[Andy Moreton]

On Sat 23 Oct 2021, Andy Moreton wrote:

> On Fri 22 Oct 2021, Eli Zaretskii wrote:
>
>>> From: Arash Esbati <arash@gnu.org>
>>> Date: Fri, 22 Oct 2021 17:21:49 +0200
>>> 
>>> current master (commit f7a2ff3b) doesn't build with Msys2.  The message
>>> is:
>>> 
>>> --8<---------------cut here---------------start------------->8---
>>> make[1]: Entering directory '/z/pathto/emacs/lib-src'
>>>   CC       ntlib.o
>>>   RC       emacsclient.res
>>>   CC       pop.o
>>> In file included from 
>>> z:/pathto/msys64/mingw64/x86_64-w64-mingw32/include/guiddef.h:154,
>>>                  from 
>>> z:/pathto/msys64/mingw64/x86_64-w64-mingw32/include/winnt.h:635,
>>>                  from 
>>> z:/pathto/msys64/mingw64/x86_64-w64-mingw32/include/minwindef.h:163,
>>>                  from 
>>> z:/pathto/msys64/mingw64/x86_64-w64-mingw32/include/windef.h:9,
>>>                  from 
>>> z:/pathto/msys64/mingw64/x86_64-w64-mingw32/include/windows.h:69,
>>>                  from ntlib.c:23:
>>> ../lib/string.h:965:1: error: expected ',' or ';' before 
>>> '_GL_ATTRIBUTE_MALLOC'
>>>   965 | _GL_FUNCDECL_SYS (strdup, char *,
>>>       | ^~~~~~~~~~~~~~~~
>>> make[1]: *** [Makefile:418: ntlib.o] Error 1
>>> make[1]: Leaving directory '/z/pathto/emacs/lib-src'
>>> --8<---------------cut here---------------end--------------->8---
>>> 
>>> I'm not sure this is an Emacs issue or not.  GCC 11.2 landed also today
>>> on my HD.  Can others reproduce this?
>>
>> lib/string.h is a Gnulib header, so I suggest to report this to
>> bug-gnulib@gnu.org.  Or maybe it's some problem with MinGW64 headers
>> (did that get updated as well recently?).  In any case, I just rebuilt
>> the relevant files, and saw no problem (I'm a happy user of GCC 9.2.0).
>
> I see this too. It seems to be an issue with gnulib and GCC 11.
> Commenting  out this hunk from lib/string.in.h L456 works around the problem.
>
> # if __GNUC__ >= 11 && !defined strdup
> /* For -Wmismatched-dealloc: Associate strdup with free or rpl_free.  */
> _GL_FUNCDECL_SYS (strdup, char *,
>                   (char const *__s)
>                   _GL_ARG_NONNULL ((1))
>                   _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE);
> # endif
>
>
> Hopefully Paul Eggert will be along soon to come up with a proper fix in
> gnulib.

Note that this problem also occurs on emacs-28, and the workaround above
also works. Thus this needs a gnulib fix before the release.

    AndyM