• Paul Eggert's avatar
    gnulib: import mktime and move-if-change fixes from gnulib · 3de84ad9
    Paul Eggert authored
    * configure: Regenerate from the following.
    2011-01-30  Paul Eggert  <eggert@cs.ucla.edu>
    mktime: clarify long_int width checking
    * lib/mktime.c (long_int_is_wide_enough): Move this assertion to
    the top level, to make it clearer that the assumption about
    long_int width is being checked.  See
    2011-01-29  Paul Eggert  <eggert@cs.ucla.edu>
    TYPE_MAXIMUM: avoid theoretically undefined behavior
    * lib/intprops.h (TYPE_MINIMUM, TYPE_MAXIMUM): Do not shift a
    negative number, which the C Standard says has undefined behavior.
    In practice this is not a problem, but might as well do it by the book.
    Reported by Rich Felker and Eric Blake; see
    * m4/mktime.m4 (AC_FUNC_MKTIME): Likewise.
    * lib/mktime.c (TYPE_MAXIMUM): Redo slightly to match the others.
    mktime: #undef mktime before #defining it
    * lib/mktime.c (mktime) [DEBUG]: #undef mktime before #defining it.
    mktime: systematically normalize tm_isdst comparisons
    * lib/mktime.c (isdst_differ): New function.
    (__mktime_internal): Use it systematically for all isdst comparisons.
    This completes the fix for libc BZ #6723, and removes the need for
    normalizing tm_isdst.  See
    (not_equal_tm) [DEBUG]: Use isdst_differ here, too.
    mktime: fix some integer overflow issues and sidestep the rest
    This was prompted by a bug report by Benjamin Lindner for MinGW
    His bug is due to signed integer overflow (0 - INT_MIN), and I
    I scanned through mktime.c looking for other integer overflow
    problems, fixing all the bugs I found.
    Although the C Standard says the resulting code is still not safe
    in the presence of integer overflow, in practice it should be good
    enough for all real-world two's-complement implementations, except
    for debugging environments that deliberately trap on integer
    overflow (e.g., gcc -ftrapv).
    * lib/mktime.c (WRAPV): New macro.
    (SHR): Also check that long_int and time_t shift right in the
    usual way, before using the fast-but-unportable method.
    used.  The code already assumed two's complement, so there's
    no need to test for alternatives.  All uses removed.
    (TYPE_MAXIMUM): Don't rely here on overflow behavior not defined by
    the C standard.  Problem reported by Rich Felker in
    (twos_complement_arithmetic): Also check long_int and time_t.
    (time_t_avg, time_t_add_ok, time_t_int_add_ok): New functions.
    (guess_time_tm, ranged_convert, __mktime_internal): Use them.
    (__mktime_internal): Avoid integer overflow with unary subtraction
    in two instances where -1 - X is an adequate replacement for -X,
    since the calculations are approximate.
    2011-01-29  Eric Blake  <eblake@redhat.com>
    mktime: avoid infinite loop
    * m4/mktime.m4 (AC_FUNC_MKTIME): Avoid overflow on possibly-signed
    type; behavior is still undefined but portable to all known targets.
    Reported by Rich Felker.
    2011-01-28  Paul Eggert  <eggert@cs.ucla.edu>
    mktime: avoid problems on NetBSD 5 / i386
    * lib/mktime.c (long_int): New type.  This works around a problem
    on NetBSD 5 / i386, where 'long int' and 'int' are both 32 bits
    but time_t is 64 bits, and where I expect the existing code is
    wrong in some cases.
    (leapyear, ydhms_diff, guess_time_tm, __mktime_internal): Use it.
    (ydhms_diff): Bring back the compile-time check for wide-enough
    year and yday.
    mktime: fix misspelling in comment
    * lib/mktime.c (__mktime_internal): Fix misspelling in comment.
    This merges all recent glibc changes of importance.
    2011-01-28  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
    move-if-change: cope with concurrent mv of identical file.
    * move-if-change (CMPPROG): Accept environment
    variable as an override for `cmp'.
    (usage): Document CMPPROG.
    Adjust comparison to drop stdout.  Cope with failure of mv if
    the target file exists and is identical to the source, for
    parallel builds.
    Report from H.J. Lu against binutils in PR binutils/12283.
ChangeLog 273 KB