Hi Paul,
> which doesn’t work when
> compiled with stricter C17-and-earlier compilers. The feature is
> using ‘#define f(a, ...) b’ and calling ‘f’ with only one arg.
1) Comparing ISO C 17 § 6.10.3.(12) vs. ISO C 23 § 6.10.5.(12):
The C 17 text also has the "(if any)" part; so that means that
in C 17 one needs to write
f (x,)
not
f (x)
How about, instead of defining two macros
_GL_FUNCDECL_SYS (func, rettype, parameters);
_GL_FUNCATTR_SYS (func, rettype, parameters, attributes);
we would have one macro
_GL_FUNCDECL_SYS (func, rettype, parameters, attributes);
and invoke it with 4 arguments always, e.g.
_GL_FUNCDECL_SYS (getprogname, const char *, (void),);
_GL_FUNCATTR_SYS (getprogname, const char *, (void), _GL_ATTRIBUTE_PURE);
To me, that is simpler. While empty macro arguments are not "esthetic"
for some people, this is only a question of getting used to it. Empty
macro arguments are supported since C 99; only K&R C preprocessors had
problems with them.
2) The CI reports a compilation error on many platforms:
In file included from ./uchar.h:61,
from ../../gllib/btoc32.c:23:
./wchar.h:815:61: error: macro "_GL_FUNCDECL_RPL" passed 4 arguments, but takes
just 3
815 | _GL_FUNCDECL_RPL (btowc, wint_t, (int c), _GL_ATTRIBUTE_PURE);
| ^
In file included from ./uchar.h:61,
from ../../gllib/btoc32.c:23:
./wchar.h:287: note: macro "_GL_FUNCDECL_RPL" defined here
287 | #define _GL_FUNCDECL_RPL(func,rettype,parameters) \
|
make[4]: *** [Makefile:11826: btoc32.o] Error 1
Bruno
