From: Florian Weimer <fweimer@redhat.com>
To: Rich Felker <dalias@libc.org>
Cc: "Adhemerval Zanella Netto" <adhemerval.zanella@linaro.org>,
"Antonios Salios via Libc-help" <libc-help@sourceware.org>,
"Antonios Salios" <antonios@mwa.re>,
"Jan Henrik Weinstock" <jan@mwa.re>,
"Lukas Jünger" <lukas@mwa.re>
Subject: Re: 64 bit time_t on riscv32
Date: Tue, 16 Jan 2024 17:22:55 +0100 [thread overview]
Message-ID: <87r0ih1c4g.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20240116155650.GQ22081@brightrain.aerifal.cx> (Rich Felker's message of "Tue, 16 Jan 2024 10:56:51 -0500")
* Rich Felker:
> On Tue, Jan 16, 2024 at 04:46:17PM +0100, Florian Weimer wrote:
>> * Adhemerval Zanella Netto:
>>
>> > My understanding was __USE_TIME_BITS64 would be required only for ABIs
>> > that actually would multiple time_t sizes and the glibc 64 bit time_t
>> > supported was added on this assumption. However, the design document
>> > does state __USE_TIME_BITS64 would be defined even for architectures
>> > where is does not require it. I it was not really caught in development
>> > because the design creator was not really much involved at the time.
>> >
>> > I think it should be feasible to fix it, although backporting it would
>> > generate a quite large patch.
>>
>> It will break applications that use __USE_TIME_BITS64 with glibc's
>> current semantics centered on time64 redirects (incorrectly, of
>> course—it's an internal macro). I think the use in the kernel is
>> probably easier to address, and it has to be changed for compatibility
>> with other libcs anyway.
>
> If there are applications assuming __USE_TIME_BITS64 implies redirects
> and doing some hack around that, they really need to be fixed not to
> do that. It will break on musl with (not yet merged) rv32 port as well
> as any future 32-bit ports, which won't have any redirects because
> there is no legacy 32-bit time_t ABI to support.
That's actually not a problem because __USE_TIME_BITS64 is not defined
on rv32 et al. (hence the complaint about what the UAPI headers are
doing).
Thanks,
Florian
next prev parent reply other threads:[~2024-01-16 16:23 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-15 12:52 Antonios Salios
2024-01-15 13:40 ` Florian Weimer
2024-01-15 19:55 ` Adhemerval Zanella Netto
2024-01-15 20:15 ` Adhemerval Zanella Netto
2024-01-15 20:29 ` Arnd Bergmann
2024-01-15 22:26 ` Rich Felker
2024-01-16 11:19 ` Adhemerval Zanella Netto
2024-01-16 15:46 ` Florian Weimer
2024-01-16 15:56 ` Rich Felker
2024-01-16 16:22 ` Florian Weimer [this message]
2024-01-16 16:29 ` Adhemerval Zanella Netto
2024-01-16 20:43 ` Rich Felker
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