On Wed, Jun 08, 2022 at 09:44:19PM +0200, Marc Espie wrote:
> Naddy told me about an app that wants a gnu-m4 extension that
> requires >9 arguments to macros.
>
> I wrote a very quick patch that seems to do the work. There are probably
> lots of kinks to work out, it's been very lightly tested.
> (in particular, I haven't looked at stuff like $* and friends yet, maybe
> they work, maybe they won't)
>
> But if anyone requires this type of functionality, I'd like them to chime
> in.
>
>
> Index: eval.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/m4/eval.c,v
> retrieving revision 1.78
> diff -u -p -r1.78 eval.c
> --- eval.c 28 Jun 2019 05:35:34 -0000 1.78
> +++ eval.c 8 Jun 2022 13:03:29 -0000
> @@ -40,6 +40,7 @@
> */
>
> #include <sys/types.h>
> +#include <ctype.h>
> #include <err.h>
> #include <errno.h>
> #include <limits.h>
> @@ -542,6 +543,21 @@ expand_macro(const char *argv[], int arg
> p++;
> p--; /* last character of defn */
> while (p > t) {
> + if (mimic_gnu && isdigit(*p)) {
> + const char *pos = p;
> + int mult = 1;
> + argno = 0;
> + while (isdigit(*pos) && pos > t) {
> + argno += mult * (*pos - '0');
> + mult *= 10;
> + pos--;
> + }
> + if (*pos == ARGFLAG && argno < argc -1) {
> + pbstr(argv[argno + 1]);
> + p = pos-1;
> + continue;
> + }
> + }
> if (*(p - 1) != ARGFLAG)
> PUSHBACK(*p);
> else {
>
>
That code appears to work just fine and we even have a trivial regress test.
In the mean time, naddy@ tells me that the port in question moved away from
using that specific gnu-m4 extension.
On one side, that code is 100% self-contained and safe for non gnu-m4 compat
mode. And it went through a full bulk build without any issue.
On the other side, I don't know if some other stuff might rely on it
eventually. Among other things it is quite possible someone wrote an autoconf
macro somewhere that actually requires over 9 parameters.
So the question is: do I shelve it, or commit it ? I don't really care all
that much either way, I would just love to close the subject.
