timezone: Move to the XSI/POSIX definition for timezone.

The old timezone(3) function has long since been obsolete and has a
fatally flawed interface. Retain this function for compatibility
purposes, but shift to providing the offset from UTC in the timezone
variable, whether or not the timezone observes summer time in the
'daylight' variable. Document the tzname variable that's already been
set. Also make _tztab() static. It's not used in libc (or anywhere in
the tree) and it's not exported as a public dynamic symbol.

Sponsored by: Netflix
Reviewed by: brooks, kib
Differential Revision: https://reviews.freebsd.org/D44281

include: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

time.h: Fix visibility check for C11 and C23 features.

__BSD_VISIBLE is always defined; we need to check if it's true.

Fixes: d02489d11aed 9b5d724cad10
MFC after: 3 days
Reviewed by: brooks, imp
Differential Revision: https://reviews.freebsd.org/D41733

libc: Add timespec_getres(3) as per C23.

This also adds support for TIME_MONOTONIC to timespec_get(3).

Reviewed by: allanjude
Differential Revision: https://reviews.freebsd.org/D41524

Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

libc: Remove prototype and documentation for tzsetwall().

PR: 269445
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D38481

time.h: reduce CLOCK_ namespace pollution, move to _clock_id.h

Attempt to comply with the strict namespace pollution requirements of
_POSIX_C_SOURCE. Add guards to limit visitbility of CLOCK_ and TIMER_
defines as appropriate. Only define the CLOCK_ variables relevant to the
specific standards. Move all the sharing to sys/_clock_id.h and make
time.h and sys/time.h both include that rather than copy due to the
now large number of clocks and compat defines.

Please note: The old time.h previously used these newer dates:
CLOCK_REALTIME 199506
CLOCK_MONOTONIC 200112
CLOCK_THREAD_CPUTIME_ID 200112
CLOCK_PROCESS_CPUTIME_ID 200112

but glibc defines all of these for 199309. glibc uses this date for all
these values, however, only CLOCK_REALTIME was in IEEE 1003.1b. Add a
comment about this to document it. A large number of programs and
libraries assume that these will be defined for _POSIX_C_SOURCE =
199309.

In addition, leak CLOCK_UPTIME_FAST for the pocl package until it can be
updated to use a simple CLOCK_MONOTONIC.

Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D31056

Make CLOCK_REALTIME and TIMER_ABSTIME available for XOPEN_SOURCE >= 500.

Reported by: jbeich
PR: 247701
Reviewed by: jilles
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25554

Correctly check for C++17 and higher when declaring timespec_get()

Summary:
In rS338751, the check to declare `timespec_get()` for C++17 and higher
was incorrectly done against a `cplusplus` define, while it should have
been `__cplusplus`.

Fix this by using `__cplusplus`, and also bump `__FreeBSD_version` so it
becomes possible to correctly check for `timespec_get()` in upstream
libc++ headers.

Reviewed by: brooks, emaste
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D22735

Fix C11 and POSIX 1003.1b-1993 compliance in time.h

Only expose timespec_get in C11, C++17, or BSD code. Always define
struct timespect if defining timespec_get.

PR: 231425
Reviewed by: kib
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D17174

Bring in timespce_get form NetBSD.

Bring in the functionality for timespec_get from NetBSD. I've lightly
edited the .c file to remove _DIAGASSERT because FreeBSD doesn't have
that functionality and the typical #define'ing it to assert isn't
right here. The man page is verbatim from NetBSD, but will be revised
as part of a larger cleanup of the time man pages (they are
inconsistent and vague in all the wrong places).

Differential Review: https://reviews.freebsd.org/D16649

Add time2posix and posix2time to time.h

These are documented in `time2posix.3` but the symbols are not actually
visible. Since these are not POSIX hide them behind _BSD_VISIBLE.

Reviewed by: wollman
Differential Revision: https://reviews.freebsd.org/D15530

Do not include float interfaces when using libsa.

We don't support float in the boot loaders, so don't include
interfaces for float or double in systems headers. In addition, take
the unusual step of spiking double and float to prevent any more
accidental seepage.

include: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Add clock_nanosleep()

Add a clock_nanosleep() syscall, as specified by POSIX.
Make nanosleep() a wrapper around it.

Attach the clock_nanosleep test from NetBSD. Adjust it for the
FreeBSD behavior of updating rmtp only when interrupted by a signal.
I believe this to be POSIX-compliant, since POSIX mentions the rmtp
parameter only in the paragraph about EINTR. This is also what
Linux does. (NetBSD updates rmtp unconditionally.)

Copy the whole nanosleep.2 man page from NetBSD because it is complete
and closely resembles the POSIX description. Edit, polish, and reword it
a bit, being sure to keep any relevant text from the FreeBSD page.

Reviewed by: kib, ngie, jilles
MFC after: 3 weeks
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D10020

Export the mq_getfd_np() symbol from librt.so, which allows to get
file descriptor for the given posix mqueue. Export the
timer_oshandle_np() symbol to get ktimer id for the given posix timer.

Requested by: Lewis Donzis <lew@perftech.com>
Reviewed by: jilles
Discussed with: kan
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Add CLOCK_PROCESS_CPUTIME_ID to <time.h>, to synchronize the CLOCK_*
values with those in <sys/time.h>. Otherwise, if a program includes
<time.h> before <sys/time.h>, the CLOCK_PROCESS_CPUTIME_ID macro never
gets defined.

Reviewed by: davidxu
X-MFC-With: 239347

Add missing prototype for clock_getcpuclockid.

Correctly expose xlocale functions if people include the headers in the wrong
order (as some ports apparently do).

Approved by: dim (mentor)

Reapply 227753 (xlocale cleanup), plus some fixes so that it passes build
universe with gcc.

Approved by: dim (mentor)

Revert r231673 and r231682 for now, until we can run a full make
universe with them. Sorry for the breakage.

Pointy hat to: me and brooks

Cleanup of xlocale:

- Address performance regressions encountered by das@ by caching per-thread
data in TLS where available.
- Add a __NO_TLS flag to cdefs.h to indicate where not available.
- Reorganise the xlocale.h definitions into xlocale/*.h so that they can be
included from multiple places.
- Export the POSIX2008 subset of xlocale when POSIX2008 says it should be
exported, independently of whether xlocale.h is included.
- Fix the bug where programs using ctype functions always assumed ASCII unless
recompiled.
- Fix some style(9) violations.

Reviewed by: brooks (mentor)
Approved by: dim (mentor)

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

Remove the Berkeley clause 3's.
Add a few $FreeBSD$

- Import the HEAD csup code which is the basis for the cvsmode work.

Add POSIX pthread API pthread_getcpuclockid() to get a thread's cpu
time clock id.

Copy the new CLOCK_ defines from sys/time.h for SUSv3 compatibility.

Approved by: rwatson

Add POSIX timer interfaces.

Define CLOCK_* and TIMER_* in time.h, where they are supposed to be.

Change the definition of NULL on ia64 (for LP64 compilations) from
an int constant to a long constant. This change improves consistency
in the following two ways:
1. The first 8 arguments are always passed in registers on ia64, which
by virtue of the generated code implicitly widens ints to longs and
allows the use of an 32-bit integral type for 64-bit arguments.
Subsequent arguments are passed onto the memory stack, which does
not exhibit the same behaviour and consequently do not allow this.
In practice this means that variadic functions taking pointers
and given NULL (without cast) work as long as the NULL is passed
in one of the first 8 arguments. A SIGSEGV is more likely the
result if such would be done for stack-based arguments. This is
due to the fact that the upper 4 bytes remain undefined.
2. All 64-bit platforms that FreeBSD supports, with the obvious
exception of ia64, allow 32-bit integral types (specifically NULL)
when 64-bit pointers are expected in variadic functions by way of
how the compiler generates code. As such, code that works correctly
(whether rightfully so or not) on any platform other than ia64, may
fail on ia64.

To more easily allow tweaking of the definition of NULL, this commit
removes the 12 definitions in the various headers and puts it in a
new header that can be included whenever NULL is to be made visible.

This commit fixes GNOME, emacs, xemacs and a whole bunch of ports
that I don't particularly care about at this time...

Style: One space between "restrict" qualifier and "*".

Now that _BSD_CLK_TCK_ and _BSD_CLOCKS_PER_SEC_ are the same on all
architectures, move the definition directly into <time.h> and finish
the removal of <machine/ansi.h>.

o Merge <machine/ansi.h> and <machine/types.h> into a new header
called <machine/_types.h>.
o <machine/ansi.h> will continue to live so it can define MD clock
macros, which are only MD because of gratuitous differences between
architectures.
o Change all headers to make use of this. This mainly involves
changing:
#ifdef _BSD_FOO_T_
typedef _BSD_FOO_T_ foo_t;
#undef _BSD_FOO_T_
#endif
to:
#ifndef _FOO_T_DECLARED
typedef __foo_t foo_t;
#define _FOO_T_DECLARED
#endif

Concept by: bde
Reviewed by: jake, obrien

- Add the 'restrict' qualifier to the function definition of
strftime(3) for IEEE Std 1003.1-2001 compliance and remove
excessive usage of the 'const' qualifier that was neither
present in the prototype in the publice header, nor in the
local prototype just above the function definition.
- Replace the K&R function definition with a ANSI-C one.
- Update the prototype of strftime(3) in its manual page.

- Add the C99 'restrict' qualifier using the '__restrict' macro to
function prototype and definition of strptime(3).
- Update the manual page.

The thread-safe time functions appear to have been introduced as of
ISO 9945-1: 1996 (according to the change bars therein), which corresponds
to 1003.1c-1995. Give them appropriate visibility protection.

Resort namespace blocks into a more sensible order. Delete a redundant
comment.

Move dillon's time conversion functions to a new header <timeconv.h>.
Since they were never documented and have never appeared in a FreeBSD
release, no repo-copy of the header is done. This removes namespace
pollution from <time.h>.

Clean up a bit of namespace pollution which crept in with the last rev.

Submitted by: bde

Partially fix namespace visibility issues by using new visibility macros.
Some issues still remain, and will require research in old POSIX standards
if we care to get them right.

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

I've been meaning to do this for a while. Add an underscore to the
time_to_xxx() and xxx_to_time() functions. e.g. _time_to_xxx()
instead of time_to_xxx(), to make it more obvious that these are
stopgap functions & placemarkers and not meant to create a defacto
standard. They will eventually be replaced when a real standard
comes out of committee.

Add time_to_int(), int_to_time(), time_to_long(), long_to_time().

Add routines to convert time_t to/from fixed-bit fields. These routines
serve two purposes: (1) so we can maintain backwards compatibility with
protocols (rwhod, dump, etc...) that either assume time_t is 32 bits or
assume sizeof(time_t) == sizeof(int), or make other similar assumptions.
(2) To tag such routines (by the presence of these calls) for future
cleanup/extension work.

The 32->64 routine, time32_to_time() (when time_t is 64 bits, that is),
is defined specifically to implement temporal locality to properly set the
msb bits of a 64 bit time_t quantity, using the 50 year rule. The locality
code has not been implemented yet (and doesn't need to be for a while),
but that is the intent. This will allow us to maintain backwards protocol
compatibility past 2038.

These routines are intended to be platform and time_t agnostic.

MFC after: 1 week

It's not CUT (the french would accept that back in 1879) and TUC wasn't
palatable to the rest of the world. UTC was the compromise.

PR: 26238
Submitted by: Ying-Chieh Liao <ijliao@terry.dragon2.net>

Make ctime_r, asctime_r, gmtime_r, and localtime_r available in libc.

Change return type of strptime from const char* to char*.
const char* was wrong and nonstandard.

Add extern declaration for `tzname[]' to make this header comply better
to POSIX90.

2-rounds-of-review-by: bde

ctime_r and asctime_r are not implemented.
prototypes in time.h do not match POSIX.

PR: 6345
Reviewed by: phk
Submitted by: Dmitry Khrustalev <dima@xyzzy.machaon.ru>

Finish _POSIX_PRIORITY_SCHEDULING. Needs P1003_1B and
_KPOSIX_PRIORITY_SCHEDULING options to work. Changes:

Change all "posix4" to "p1003_1b". Misnamed files are left
as "posix4" until I'm told if I can simply delete them and add
new ones;

Add _POSIX_PRIORITY_SCHEDULING system calls for FreeBSD and Linux;

Add man pages for _POSIX_PRIORITY_SCHEDULING system calls;

Add options to LINT;

Minor fixes to P1003_1B code during testing.

Import strptime(3) into libc. We've got permission by Kevin Ruddy to
modify the original `no modifications' copyright message, and i've
included his mail into the source file.

The common localization functions between strptime(3) and strftime(3)
have been broken out into timelocal.[ch].

struct timespec needs to be useable with just <time.h>, but needs to not
conflict with the kernel visible one. Make the new stuff not visible if
_ANSI_SOURCE or _POSIX_SOURCE is defined (!) because the new things are
not part of the base 1003.1-1990 standard (or ansi).

Add clockid_t definition like in sys/types.h to allow time.h
to be included without sys/types.h, it fixes broken groff compilation

Oops, move clock_*() and nanosleep() to time.h

Submitted by: Peter Dufault <dufault@hda.com>

Change prototypes for gmtime_r() and localtime_r() in accordance with
IEEE pthreads specification.

Reviewed by: julian and (hsu?)
Submitted by: John Birrel(L?)

changes for threadsafe operations

Define CLK_TCK right.

Define CLOCKS_PER_SEC.

Define CLK_TCK only if _ANSI_SOURCE is not defined.

Don't include <machine/limits.h> to get the definition of CLK_TCK.
CLK_TCK should never have been defined there, and the inclusion
polluted the namespace.

Declare useful functions (timelocal() and timegm())

BSD 4.4 Lite Include Sources