lib: 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

libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

General 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.

1) Remove my overcomplicated error fallback and just return error
immediatelly as old code does, now for append modes too.
Real use case for such fallback is impossible (unless specially crafted).

2) Remove now unneded include I forgot to remove in prev. commits.

MFC after: 1 week

Reorganize code to elimitate one _sseek() call for append modes.

MFC after: 1 week

Microoptimize.

Addition to prev. commit.
In some edge cases fp->_p can be changed in _sseek(), recalculate.

PR: 204156
MFC after: 1 week

Don't seek to the end if write buffer is empty (in append modes).

PR: 204156
MFC after: 1 week

Add _flags2 per jhb@ suggestion since no room left in _flags.
Rewrite O_APPEND flag checking using new __S2OAP flag.

MFC after: 3 weeks

Since no room left in the _flags, reuse __SALC for O_APPEND.
It helps to remove _fcntl() call from _ftello() and optimize seek position
calculation in _swrite().

MFC after: 3 weeks

For "a"-mode files and rewind/fseek + fwrite combination return meaningful
value now, like Apple does, but avoid their __sflush physical write
performance degradation as much as possible.

Back the whole change out until I figure out how to obtain O_APPEND,
it can't be used in this field at all.

Checking for __SAPP alone is not enough because it is emulated O_APPEND
only, so works for only special fdopen() case. Add real O_APPEND too.

Revert r268984:
Check for __SAPP flag before calling sflush. This avoids
performance degradation compared to the previous approach.

Submitted by: ache
MFC after: 2 weeks

ftello: return 1 when seeking offset on an append stream.

Obtained from: Apple Inc. (Libc 997.90.3)
Phabric: D442
MFC after: 2 weeks

Convert libc/stdio from K&R to ANSI C

And add '__restrict' where it appeared in the header prototypes

Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic all number the clauses 1 through 3,
so follow suit to make comparison easier.

Acked-by: imp@

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.

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

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove 'register' keyword.

Move all stdio internal flags processing and setting out of __sread(),
__swrite() and __sseek() to higher level. According to funopen(3) they all
are just wrappers to something like standard read(2), write(2) and
lseek(2), i.e. must not touch stdio internals because they are replaceable
with any other functions knows nothing about stdio internals. See example
of funopen(3) usage in sendmail sources f.e.

NOTE: this is original stdio bug, not result of my range checkin added.

Strict in the POSIX sence, if file position is unspecified after ungetc() at
0, return that we can't specify it, i.e. error with ESPIPE.
(hint from: "Peter S. Housel" <housel@acm.org>)

Back out sinit() addition, not needed after various code simplifications.

If position is underflowed, don't try to hide that fact by recovery, just
return EIO and set __SERR to mark stream as inconsistent.

Back out disabling ungetc() at 0, use different solution:
keep negative offset internally, but return 0 externally in ftell*()
I.e. use 0 now as 'unspecified value' per POSIX ungetc() description.

Add originally missing __sinit() call.

Simplify offset underflow checks even more

Disallow ungetc at offset 0 (to prevent negative offset happens), so simplify
checks in ftell.

Drop buffer first, _then_ ask for real position

The same big piece of ftell code repeated in 3 places. Simplify things moving
it into one subfunction instead.
Try to use real offset in strange cases.

If file offset is smaller than internal buffer character left count, just drop
internal buffer and trust offset, not return error.

Try to discard some ungetc data in saved internal buffer checks too,
if offset tends to be negative.

Add more EOVERFLOW checks.

When file offset tends to be negative due to internal and ungetc buffers
additions counted, try to discard some ungetc data first, then return EBADF.
Later one can happens if lseek(fileno(fd),...) called f.e. POSIX says that
ungetc beyond beginning of the file results are undefined, so we can just
discard some of ungetc data in that case.

Don't rely on gcc cast when checking for overflow, use OFF_MAX.

Cosmetique.

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

$Id$ -> $FreeBSD$

Added functions fseeko() and ftello() (from susv2).
Fixed fgetpos() and fsetpos() for offsets > 2GB.

PR: 8637
Submitted by: Dan Nelson <dnelson@emsphone.com> (adjusted by me a little)

Add FILE locking stubs for libc.

Change the FILE locking to support kernel threads when linked with
libpthread (which you haven't see yet). This requires that libc become
thread-safe and thread-aware, testing __isthreaded before attempting
to do lock/unlock calls. The impact on non-threaded programs is minor.
This change works with libc_r, so it's the best compromise.

Merge from Lite2

Import CSRG 4.4BSD-Lite2 lib/libc onto vendor branch

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Suggested by: Bruce Evans, Jeffrey Hsu, Gary Palmer

Added $Id$'s to files that were lacking them (gpalmer), made some
cosmetic changes to conform to style guidelines (bde) and checked
against NetBSD and Lite2 to remove unnecessary divergences (hsu, bde)

One last code cleanup:-

Removed spurious casts in fseek.c and stdio.c.
Added missing function argument in fwalk.c.
Added missing header include in flags.c and rget.c.
Put in casts where int's were being passed as size_t's.
Put in missing prototypes for static functions.
Changed second args of __sflags() inflags.c and writehook() in vasprintf.c
from char * to const char * to conform to prototypes.

This directory now compiles with no warnings with -Wall under
gcc-2.6.3 and with considerably less warnings than before with the
ultra-pedantic script I used for testing. (Most of the remaining ones
are due to const poisoning).

Removed now-bogus casts that were to hide the inconsistency between the
nonstandard normal version and the standard threaded version.

Removed a bogus L in a constant. fpos_t's aren't longs, and casting to
fpos_t would be verbose.

Fix incorrect parameter types.

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

changes for threadsafe operations

BSD 4.4 Lite Lib Sources