glibc/support/timespec-sub.c
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

72 lines
2.0 KiB
C

/* Subtract two struct timespec values.
Copyright (C) 2011-2019 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 difference between 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_sub (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 rns = ns;
time_t tmin = TYPE_MINIMUM (time_t);
time_t tmax = TYPE_MAXIMUM (time_t);
if (ns < 0)
{
rns = ns + TIMESPEC_HZ;
if (bs < tmax)
bs++;
else if (- TYPE_SIGNED (time_t) < rs)
rs--;
else
goto low_overflow;
}
/* INT_SUBTRACT_WRAPV is not appropriate since time_t might be unsigned.
In theory time_t might be narrower than int, so plain
INT_SUBTRACT_OVERFLOW does not suffice. */
if (! INT_SUBTRACT_OVERFLOW (rs, bs) && tmin <= rs - bs && rs - bs <= tmax)
rs -= bs;
else
{
if (rs < 0)
{
low_overflow:
rs = tmin;
rns = 0;
}
else
{
rs = tmax;
rns = TIMESPEC_HZ - 1;
}
}
return make_timespec (rs, rns);
}