Re: Fails to build on arm{el,hf} with 64bit time_t: export-cache.c:110:51: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘time_t’ {aka ‘long long int’} [-Werror=format=]

[Chuck Lever III <chuck.lever@oracle.com>]

> On Apr 6, 2024, at 3:15 PM, Salvatore Bonaccorso <carnil@debian.org> wrote:
> 
> Hi Chuck, hi Steve,
> 
> In Debian, as you might have heard there is a 64bit time_t
> transition[1] ongoing affecting the armel and armhf architectures.
> While doing so, nfs-utils was found to fail to build for those
> architectures after the switch, reported in Debian as [2]. Vladimir
> Petko from Ubuntu has as well filled it in [3].
> 
> [1]: https://lists.debian.org/debian-devel-announce/2024/02/msg00005.html
> [2]: https://bugs.debian.org/1067829
> [3]: https://bugzilla.kernel.org/show_bug.cgi?id=218540
> 
> The report is full-quoted below. 
> 
> Vladimir Petko has created a patch in the bugzilla which I'm attaching
> here as well. If this is not an acceptable format due to missing
> Signed-off's I'm attaching a variant with a Suggested-by for Vladimir
> to properly credit the patch origin.
> 
> Let me know if that works. I changed it slightly and only casting to
> long long, and made it almost checkpatch clean.

I suppose strftime(3) might be nicer, but this works.

Reviewed-by: Chuck Lever <chuck.lever@oracle.com <mailto:chuck.lever@oracle.com>>


> Regards,
> Salvatore
> 
> ----- Forwarded message from Sebastian Ramacher <sramacher@debian.org> -----
> 
> From: Sebastian Ramacher <sramacher@debian.org>
> Resent-From: Sebastian Ramacher <sramacher@debian.org>
> Reply-To: Sebastian Ramacher <sramacher@debian.org>, 1067829@bugs.debian.org
> Date: Wed, 27 Mar 2024 11:02:25 +0100
> To: Debian Bug Tracking System <submit@bugs.debian.org>
> Subject: Bug#1067829: nfs-utils: FTBFS on arm{el,hf}: export-cache.c:110:51: error: format ‘%ld’ expects argument of
> type ‘long int’, but argument 4 has type ‘time_t’ {aka ‘long long int’} [-Werror=format=]
> Delivered-To: submit@bugs.debian.org
> Message-ID: <ZgPusfnkCCvhalve@ramacher.at>
> 
> Source: nfs-utils
> Version: 1:2.6.4-3
> Severity: serious
> Tags: ftbfs
> Justification: fails to build from source (but built successfully in the past)
> X-Debbugs-Cc: sramacher@debian.org
> 
> https://buildd.debian.org/status/fetch.php?pkg=nfs-utils&arch=armel&ver=1%3A2.6.4-3%2Bb2&stamp=1711452552&raw=0
> 
> libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../support/include -I/usr/include/tirpc -I/usr/include/libxml2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -pipe -Wall -Wextra -Werror=strict-prototypes -Werror=missing-prototypes -Werror=missing-declarations -Werror=format=2 -Werror=undef -Werror=missing-include-dirs -Werror=strict-aliasing=2 -Werror=init-self -Werror=implicit-function-declaration -Werror=return-type -Werror=switch -Werror=overflow -Werror=parentheses -Werror=aggregate-return -Werror=unused-result -fno-strict-aliasing -Werror=format-overflow=2 -Werror=int-conversion -Werror=incompatible-pointer-types -Werror=misleading-indentation -Wno-cast-function-type -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c xml.c  -fPIC -DPIC -o .libs/xml.o
> export-cache.c: In function ‘junction_flush_exports_cache’:
> export-cache.c:110:51: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘time_t’ {aka ‘long long int’} [-Werror=format=]
>  110 |         snprintf(flushtime, sizeof(flushtime), "%ld\n", now);
>      |                                                 ~~^     ~~~
>      |                                                   |     |
>      |                                                   |     time_t {aka long long int}
>      |                                                   long int
>      |                                                 %lld
> libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../support/include -I/usr/include/tirpc -I/usr/include/libxml2 -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -pipe -Wall -Wextra -Werror=strict-prototypes -Werror=missing-prototypes -Werror=missing-declarations -Werror=format=2 -Werror=undef -Werror=missing-include-dirs -Werror=strict-aliasing=2 -Werror=init-self -Werror=implicit-function-declaration -Werror=return-type -Werror=switch -Werror=overflow -Werror=parentheses -Werror=aggregate-return -Werror=unused-result -fno-strict-aliasing -Werror=format-overflow=2 -Werror=int-conversion -Werror=incompatible-pointer-types -Werror=misleading-indentation -Wno-cast-function-type -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -c display.c -o display.o >/dev/null 2>&1
> cc1: some warnings being treated as errors
> make[3]: *** [Makefile:489: export-cache.lo] Error 1
> make[3]: *** Waiting for unfinished jobs....
> 
> Cheers
> -- 
> Sebastian Ramacher
> 
> ----- End forwarded message -----
> <armhf-time-t-format-error.patch><0001-junction-export-cache-cast-to-a-type-with-a-known-si.patch>

--
Chuck Lever