Eli Zaretskii wrote in
<https://lists.gnu.org/archive/html/bug-texinfo/2026-01/msg00099.html>
about the old dead mingw.org's mingw distribution:
> > gcc -DHAVE_CONFIG_H -I. -I../.. -Id:/usr/include -Wno-cast-qual
> > -Wno-conversion -Wno-float-equal -Wno-sign-compare -Wno-undef
> > -Wno-unused-function -Wno-unused-parameter -Wno-float-conversion
> > -Wimplicit-fallthrough -Wno-pedantic -Wno-sign-conversion -Wno-type-limits
> > -Wno-unused-const-variable -Wno-unsuffixed-float-constants -Wno-error -O2
> > -gdwarf-4 -g3 -MT libgnu_a-btowc.o -MD -MP -MF .deps/libgnu_a-btowc.Tpo -c
> > -o libgnu_a-btowc.o `test -f 'btowc.c' || echo './'`btowc.c
> > In file included from ./wctype.h:56,
> > from d:\usr\include\wchar.h:62,
> > from ./wchar.h:77,
> > from btowc.c:21:
> > ./wchar.h:923:1: error: unknown type name 'mbstate_t'
> > 923 | _GL_FUNCDECL_RPL (mbsinit, int, (const mbstate_t *ps), );
> > | ^~~~~~~~~~~~~~~~
> > ...
> > This is because the MinGW wchar.h includes wctype.h, so we include the
> > Gnulib's version of it, and that one then turns around and includes
> > wchar.h again. But because the MinGW wchar.h was not yet completely
> > processed, mbstate_t is not yet defined.
> >
> > I don't know how to solve this cleanly.
We have a technique for this situation in Gnulib. But it is fragile, therefore
let me ask one or two questions before applying it.
gnulib/lib/wctype.in.h has this piece of code:
-------------------------------------------------------------------------------
#if (defined __MINGW32__ && defined __CTYPE_H_SOURCED__)
/* Special invocation convention:
- With MinGW 3.22, when <ctype.h> includes <wctype.h>, only some part of
<wctype.h> is being processed, which doesn't include the idempotency
guard. */
#@INCLUDE_NEXT@ @NEXT_WCTYPE_H@
#else
/* Normal invocation convention. */
-------------------------------------------------------------------------------
In your mingw <wchar.h>, is there some preprocessor definition, that we
could test (similar to __CTYPE_H_SOURCED__)?
Bruno
