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* 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 <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00554.html>. 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 <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00493.html>. * 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 <http://sourceware.org/bugzilla/show_bug.cgi?id=6723> (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 <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00472.html>. 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. (TYPE_ONES_COMPLEMENT, TYPE_SIGNED_MAGNITUDE): Remove, no longer 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 <http://lists.gnu.org/archive/html/bug-gnulib/2011-01/msg00488.html>. (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.
87 lines
3.4 KiB
C
87 lines
3.4 KiB
C
/* intprops.h -- properties of integer types
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Copyright (C) 2001-2005, 2009-2011 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Written by Paul Eggert. */
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#ifndef GL_INTPROPS_H
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# define GL_INTPROPS_H
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# include <limits.h>
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/* The extra casts in the following macros work around compiler bugs,
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e.g., in Cray C 5.0.3.0. */
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/* True if the arithmetic type T is an integer type. bool counts as
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an integer. */
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# define TYPE_IS_INTEGER(t) ((t) 1.5 == 1)
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/* True if negative values of the signed integer type T use two's
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complement, ones' complement, or signed magnitude representation,
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respectively. Much GNU code assumes two's complement, but some
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people like to be portable to all possible C hosts. */
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# define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
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# define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
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# define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
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/* True if the arithmetic type T is signed. */
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# define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
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/* The maximum and minimum values for the integer type T. These
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macros have undefined behavior if T is signed and has padding bits.
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If this is a problem for you, please let us know how to fix it for
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your host. */
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# define TYPE_MINIMUM(t) \
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((t) (! TYPE_SIGNED (t) \
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? (t) 0 \
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: TYPE_SIGNED_MAGNITUDE (t) \
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? ~ (t) 0 \
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: ~ TYPE_MAXIMUM (t)))
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# define TYPE_MAXIMUM(t) \
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((t) (! TYPE_SIGNED (t) \
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? (t) -1 \
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: ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
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/* Return zero if T can be determined to be an unsigned type.
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Otherwise, return 1.
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When compiling with GCC, INT_STRLEN_BOUND uses this macro to obtain a
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tighter bound. Otherwise, it overestimates the true bound by one byte
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when applied to unsigned types of size 2, 4, 16, ... bytes.
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The symbol signed_type_or_expr__ is private to this header file. */
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# if __GNUC__ >= 2
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# define signed_type_or_expr__(t) TYPE_SIGNED (__typeof__ (t))
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# else
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# define signed_type_or_expr__(t) 1
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# endif
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/* Bound on length of the string representing an unsigned integer
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value representable in B bits. log10 (2.0) < 146/485. The
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smallest value of B where this bound is not tight is 2621. */
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# define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485)
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/* Bound on length of the string representing an integer type or expression T.
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Subtract 1 for the sign bit if T is signed, and then add 1 more for
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a minus sign if needed. */
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# define INT_STRLEN_BOUND(t) \
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(INT_BITS_STRLEN_BOUND (sizeof (t) * CHAR_BIT - signed_type_or_expr__ (t)) \
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+ signed_type_or_expr__ (t))
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/* Bound on buffer size needed to represent an integer type or expression T,
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including the terminating null. */
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# define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
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#endif /* GL_INTPROPS_H */
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