Re: 64 bit numbers vs format strings - Mailing list pgsql-hackers

On Mon, Mar 17, 2025 at 8:09 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Peter Eisentraut <peter@eisentraut.org> writes:
> > This is not really possible.  The <PRIxxx> behavior is baked deeply into
> > the gettext code.  (Also note that you don't only need support in
> > xgettext, which is part of our build system, but also in the runtime
> > library, which we don't control.)
>
> Hmm, I find that comment fairly scary.  How do we know that the
> runtime library actually gets this right on every supported platform?
> It's surely not because we test it, because we do not.

I don't know too much about libintl and its history other than what
I've looked up for these discussions, but I can't find any other
implementations other than Sun's, GNU's and NetBSD's.  Sun/Oracle and
NetBSD went out of their way to understand these and other GNUisms.  I
am not sure if they should even be called "extensions"...  extensions
to what?  I guess the historical answer would have been "Sun's
version", but see below for a new development which raises
philosophical questions.

1.  Solaris -- the original implementation has special support for the
things GNU's added, and certainly covers this <inttypes.h> stuff:

https://docs.oracle.com/cd/E36784_01/html/E39536/gnkbn.html#ILDEVgnosj

I just tried it out on a cfarm Solaris box (well I thought I already
knew this from an earlier round of discussions about this but wanted
to check again before replying and found my old test program still
there...).  Note the "<PRId64>" in the catalogue:

tmunro@s11-sparc:~/gettext-hacking$ uname -a
SunOS s11-sparc.cfarm 5.11 11.4.78.189.2 sun4v sparc sun4v logical-domain
tmunro@s11-sparc:~/gettext-hacking$ tail -5 locales/fr/LC_MESSAGES/messages.po

#: test.c:8
#, c-format
msgid "the answer is %<PRId64>\n"
msgstr "la réponse est %<PRId64>\n"
tmunro@s11-sparc:~/gettext-hacking$ cat test.c
#include <inttypes.h>
#include <libintl.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>

#define GETTEXT_DOMAIN "messages"
#define GETTEXT_OUTPUT_DIR "locales"

int
main()
{
        setenv("LANGUAGE", "fr", 1);
        setlocale(LC_ALL, "fr_FR.UTF-8");
    bindtextdomain(GETTEXT_DOMAIN, GETTEXT_OUTPUT_DIR);
    textdomain(GETTEXT_DOMAIN);
        printf(gettext("the answer is %" PRId64 "\n"), (int64_t) 42);
}
tmunro@s11-sparc:~/gettext-hacking$ gcc test.c
tmunro@s11-sparc:~/gettext-hacking$ ./a.out
la réponse est 42

You can also see that stuff in the illumos source tree:

https://github.com/illumos/illumos-gate/blob/master/usr/src/lib/libc/port/i18n/gettext_gnu.c

2.  NetBSD -- I haven't try it myself (I can send my test program if
you are interested) but it clearly knows about GNU's system-dependent
macros, and its stated goal was to be "based on the specifications
from GNU gettext":

https://wiki.netbsd.org/projects/project/libintl/
https://github.com/NetBSD/src/blob/trunk/lib/libintl/sysdep.c

What aspect of that might not work portably?  Are there any other
implementations I'm missing?  What standard would an implementation
follow, if it were to exist?

POSIX 2024 also finally standardised gettext() and associated tools.
I don't see these macros mentioned there (after an admittedly cursory
scan of the relevant sections), or for that matter any mention of the
portability problem they solve (perhaps I'll write in about that), but
it doesn't seem to make any sense to deprive ourselves of features
supported by all known implementations that solve a real problem, just
because a standard suddenly appeared retroactively rendering them
"extensions" in some sense.  I mean, GNU is clearly functioning as a
of de facto standard of very long standing, which I think the POSIX
discussion[1] acknowledged succinctly in the description field "POSIX
defines catgets() but most software rather uses gettext()".  I don't
think I've ever seen catgets() in several decades around C and Unix.

(Amusingly the GNU maintainer showed up to say (paraphrasing) "don't
do it", and (paraphrasing) "if you want to solve a problem that we
actually have why don't you add all the missing _l function so we can
write portable multithreaded programs".  Hear hear!)

[1] https://www.austingroupbugs.net/view.php?id=1122