Re: [PATCH 0/1] newlib/libc/time/tzset_r.c(_tzset_unlocked_r): add POSIX <> quoted abbrs

[Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>]

On 2022-02-16 01:55, Corinna Vinschen wrote:
> On Feb 15 22:38, Brian Inglis wrote:
>> On 2022-02-15 15:04, Brian Inglis wrote:
>>> Submitted a newlib patch which builds okay, but cannot test, as I don't
>>> have a newlib platform to run on, and Cygwin uses it's own TZ DB code
>>> base.
>>> It should accept up to 10 character abbreviations for STD and DST
>>> matching POSIX specs including anything within < > quoted content.
>>> If someone needing this could build, test, and send feedback, I'd
>>> appreciate it.
>>> ---
>>>     newlib/libc/time/tzset_r.c | 68 ++++++++++++++++++++++++++++++++------
>>>     1 file changed, 58 insertions(+), 10 deletions(-)
>>
>> Regarding the 10 character limit above, reviewing the POSIX and tzset.c
>> documentation, the size limit should be TZNAME_MAX, so some changes may need
>> to be made to the values or the code, as _POSIX_TZNAME_MAX is the minimum
>> acceptable value:
>>
>> https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
>>
>> and the value used should be that configured:
>>
>> https://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html
>>
>> also:
>>
>> https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap08.html#tag_21_08_03_05
>>
>> newlib/libc/include/sys/unistd.h:#define _SC_TZNAME_MAX			20
>> newlib/libc/sys/rtems/include/limits.h:#define _POSIX_TZNAME_MAX	3
>> newlib/libc/sys/rtems/include/limits.h:#define TZNAME_MAX		3
>> winsup/cygwin/include/limits.h:#define _POSIX_TZNAME_MAX		6
>>
>> Discussion of whether and how to define and align TZNAME_MAX values are
>> welcome: Cygwin punts and leaves it undefined, so developers have a choice
>> of using the alternatives unistd.h sysconf(_SC_TZNAME_MAX) or
>> _POSIX_TZNAME_MAX.
>>
>> I am inclined to use if defined in order:
>> *	limits.h TZNAME_MAX
>> *	unistd.h sysconf(_SC_TZNAME_MAX) if available
>> *	limits.h _POSIX_TZNAME_MAX
>> *	6!
> 
> I'd replace 6 with #error

That's probably for the best - I'll look at adding that to a v2 patch 
set including doc update.

What is required to remake newlib libc info and man pages?
Do I need to specify a special target or maintainer mode?
Updated tzset.def libc.info are not showing up in my build or install 
dirs! I am sure I had all the tools and this used to work reliably.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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