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don't depend on integer oveflow wrapping to detect it. From Paul Eggert in

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the tz mailing list.
This commit is contained in:
christos 2011-01-14 23:35:07 +00:00
parent 979fccad2b
commit dd5b7b1566
4 changed files with 40 additions and 32 deletions
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7
lib/libc/time/Makefile
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@ -110,6 +110,10 @@ LDLIBS=
# -TTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory;
# the default is system-supplied, typically "/usr/lib/locale"
# $(GCC_DEBUG_FLAGS) if you are using GCC and want lots of checking
# $(GCC_OVERFLOW_FLAGS) if you are using GCC 3.4 or later.
# If you are using a compiler other than GCC, and if it defaults to
# undefined behavior on integer overflow, then you need to specify a flag
# saying that integer arithmetic is supposed to wrap around on overflow.
# -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU=1
# if you do not want run time warnings about formats that may cause
# year 2000 grief
@ -120,6 +124,7 @@ GCC_DEBUG_FLAGS = -Dlint -g -O -fno-common \
-Wall -Wcast-qual -Wconversion -Wmissing-prototypes \
-Wnested-externs -Wpointer-arith -Wshadow \
-Wtraditional # -Wstrict-prototypes -Wwrite-strings
GCC_OVERFLOW_FLAGS = -fwrapv
#
# If you want to use System V compatibility code, add
# -DUSG_COMPAT
@ -386,7 +391,7 @@ names:
public: $(ENCHILADA)
make maintainer-clean
make "CFLAGS=$(GCC_DEBUG_FLAGS)"
make "CFLAGS=$(GCC_DEBUG_FLAGS) $(GCC_OVERFLOW_FLAGS)"
-mkdir /tmp/,tzpublic
-for i in $(TDATA) ; do zic -v -d /tmp/,tzpublic $$i 2>&1 | grep -v "starting year" ; done
for i in $(TDATA) ; do zic -d /tmp/,tzpublic $$i || exit; done

12
lib/libc/time/localtime.c
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@ -1,4 +1,4 @@
/* $NetBSD: localtime.c,v 1.51 2011/01/06 02:41:34 christos Exp $ */
/* $NetBSD: localtime.c,v 1.52 2011/01/14 23:35:07 christos Exp $ */
/*
** This file is in the public domain, so clarified as of
@ -10,7 +10,7 @@
#if 0
static char elsieid[] = "@(#)localtime.c 8.9";
#else
__RCSID("$NetBSD: localtime.c,v 1.51 2011/01/06 02:41:34 christos Exp $");
__RCSID("$NetBSD: localtime.c,v 1.52 2011/01/14 23:35:07 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
@ -1704,8 +1704,10 @@ increment_overflow(int *number, int delta)
int number0;
number0 = *number;
if (delta < 0 ? number0 < delta - INT_MIN : INT_MAX - delta < number0)
return 1;
*number += delta;
return (*number < number0) != (delta < 0);
return 0;
}
static int
@ -1714,8 +1716,10 @@ long_increment_overflow(long *number, int delta)
long number0;
number0 = *number;
if (delta < 0 ? number0 < delta - LONG_MIN : LONG_MAX - delta < number0)
return 1;
*number += delta;
return (*number < number0) != (delta < 0);
return 0;
}
static int

35
lib/libc/time/zdump.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: zdump.c,v 1.17 2009/12/31 22:49:16 mlelstv Exp $ */
/* $NetBSD: zdump.c,v 1.18 2011/01/14 23:35:07 christos Exp $ */
/*
** This file is in the public domain, so clarified as of
** 2009-05-17 by Arthur David Olson.
@ -7,7 +7,7 @@
#include <sys/cdefs.h>
#ifndef lint
#ifndef NOID
__RCSID("$NetBSD: zdump.c,v 1.17 2009/12/31 22:49:16 mlelstv Exp $");
__RCSID("$NetBSD: zdump.c,v 1.18 2011/01/14 23:35:07 christos Exp $");
#endif /* !defined NOID */
#endif /* !defined lint */
@ -26,6 +26,7 @@ static char elsieid[] = "@(#)zdump.c 8.9";
#include "stdlib.h" /* for exit, malloc, atoi */
#include <err.h>
#include "float.h" /* for FLT_MAX and DBL_MAX */
#include "limits.h" /* for INT_MAX, LONG_MAX, etc. */
#include "ctype.h" /* for isalpha et al. */
#ifndef isascii
#define isascii(x) 1
@ -431,21 +432,25 @@ _("%s: use of -v on system with floating time_t other than float or double\n"),
}
} else if (0 > (time_t) -1) {
/*
** time_t is signed. Assume overflow wraps around.
** time_t is signed.
*/
time_t t = 0;
time_t t1 = 1;
while (t < t1) {
t = t1;
t1 = 2 * t1 + 1;
if (sizeof (time_t) == sizeof (int)) {
absolute_min_time = INT_MIN;
absolute_max_time = INT_MAX;
} else if (sizeof (time_t) == sizeof (long)) {
absolute_min_time = LONG_MIN;
absolute_max_time = LONG_MAX;
#if defined LLONG_MIN && defined LLONG_MAX
} else if (sizeof (time_t) == sizeof (long long)) {
absolute_min_time = LLONG_MIN;
absolute_max_time = LLONG_MAX;
#endif
} else {
(void) fprintf(stderr,
_("%s: use of -v on system with signed time_t whose extrema are unknown\n"),
progname);
exit(EXIT_FAILURE);
}
absolute_max_time = t;
t = -t;
absolute_min_time = t - 1;
if (t < absolute_min_time)
absolute_min_time = t;
} else {
/*
** time_t is unsigned.

18
lib/libc/time/zic.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: zic.c,v 1.26 2010/01/02 10:42:49 tsutsui Exp $ */
/* $NetBSD: zic.c,v 1.27 2011/01/14 23:35:07 christos Exp $ */
/*
** This file is in the public domain, so clarified as of
** 2006-07-17 by Arthur David Olson.
@ -10,7 +10,7 @@
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: zic.c,v 1.26 2010/01/02 10:42:49 tsutsui Exp $");
__RCSID("$NetBSD: zic.c,v 1.27 2011/01/14 23:35:07 christos Exp $");
#endif /* !defined lint */
static char elsieid[] = "@(#)zic.c 8.20";
@ -2496,14 +2496,11 @@ oadd(t1, t2)
const long t1;
const long t2;
{
register long t;
t = t1 + t2;
if ((t2 > 0 && t <= t1) || (t2 < 0 && t >= t1)) {
if (t2 < 0 ? t1 < t2 - LONG_MIN : LONG_MAX - t2 < t1) {
error(_("time overflow"));
exit(EXIT_FAILURE);
}
return t;
return t1 + t2;
}
static zic_t
@ -2511,18 +2508,15 @@ tadd(t1, t2)
const zic_t t1;
const long t2;
{
register zic_t t;
if (t1 == max_time && t2 > 0)
return max_time;
if (t1 == min_time && t2 < 0)
return min_time;
t = t1 + t2;
if ((t2 > 0 && t <= t1) || (t2 < 0 && t >= t1)) {
if (t2 < 0 ? t1 < t2 - LONG_MIN : LONG_MAX - t2 < t1) {
error(_("time overflow"));
exit(EXIT_FAILURE);
}
return t;
return t1 + t2;
}
/*