glibc/support/timespec-add.c
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

66 lines
1.8 KiB
C

/* Add two struct timespec values.
Copyright (C) 2011-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library and is also part of gnulib.
Patches to this file should be submitted to both projects.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* Return the sum of two timespec values A and B. On overflow, return
an extremal value. This assumes 0 <= tv_nsec < TIMESPEC_HZ. */
#include <config.h>
#include "timespec.h"
#include "intprops.h"
struct timespec
timespec_add (struct timespec a, struct timespec b)
{
time_t rs = a.tv_sec;
time_t bs = b.tv_sec;
int ns = a.tv_nsec + b.tv_nsec;
int nsd = ns - TIMESPEC_HZ;
int rns = ns;
if (0 <= nsd)
{
rns = nsd;
time_t bs1;
if (!INT_ADD_WRAPV (bs, 1, &bs1))
bs = bs1;
else if (rs < 0)
rs++;
else
goto high_overflow;
}
if (INT_ADD_WRAPV (rs, bs, &rs))
{
if (bs < 0)
{
rs = TYPE_MINIMUM (time_t);
rns = 0;
}
else
{
high_overflow:
rs = TYPE_MAXIMUM (time_t);
rns = TIMESPEC_HZ - 1;
}
}
return (struct timespec) { .tv_sec = rs, .tv_nsec = rns };
}