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[glibc] Make mktime etc. compatible with __time64_t
- From: Paul Eggert <eggert at sourceware dot org>
- To: glibc-cvs at sourceware dot org
- Date: 30 Apr 2019 16:02:21 -0000
- Subject: [glibc] Make mktime etc. compatible with __time64_t
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=20aa5819586ac7ad11f711bab64feda307965191
commit 20aa5819586ac7ad11f711bab64feda307965191
Author: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon Mar 18 14:14:15 2019 -0700
Make mktime etc. compatible with __time64_t
Keep these functions compatible with Gnulib while adding
__time64_t support. The basic idea is to move private API
declarations from include/time.h to time/mktime-internal.h, since
the former file cannot easily be shared with Gnulib whereas the
latter can.
Also, do some other minor cleanup while in the neighborhood.
* include/time.h: Include stdbool.h, time/mktime-internal.h.
(__mktime_internal): Move this prototype to time/mktime-internal.h,
since Gnulib needs it.
(__localtime64_r, __gmtime64_r) [__TIMESIZE == 64]:
Move these macros to time/mktime-internal.h, since Gnulib needs them.
(__mktime64, __timegm64) [__TIMESIZE != 64]: New prototypes.
(in_time_t_range): New static function.
* posix/bits/types.h (__time64_t) [__TIMESIZE == 64 && !defined __LIBC]:
Do not define as a macro in this case, so that portable code is
less tempted to use __time64_t.
* time/mktime-internal.h: Rewrite so that it does both glibc
and Gnulib work. Include time.h if not _LIBC.
(mktime_offset_t) [!_LIBC]: Define for gnulib.
(__time64_t, __gmtime64_r, __localtime64_r, __mktime64, __timegm64)
[!_LIBC || __TIMESIZE == 64]: New macros, mostly moved here
from include/time.h.
(__gmtime_r, __localtime_r, __mktime_internal) [!_LIBC]:
New macros, taken from GNulib.
(__mktime_internal): New prototype, moved here from include/time.h.
* time/mktime.c (mktime_min, mktime_max, convert_time)
(ranged_convert, __mktime_internal, __mktime64):
* time/timegm.c (__timegm64):
Use __time64_t, not time_t.
* time/mktime.c: Stop worrying about whether time_t is floating-point.
(__mktime64) [! (_LIBC && __TIMESIZE != 64)]:
Rename from mktime.
(mktime) [_LIBC && __TIMESIZE != 64]: New function.
* time/timegm.c [!_LIBC]: Include libc-config.h, not config.h,
for libc_hidden_def.
Include errno.h.
(__timegm64) [! (_LIBC && __TIMESIZE != 64)]:
Rename from timegm.
(timegm) [_LIBC && __TIMESIZE != 64]: New function.
First cut at publicizing __time64_t
Diff:
---
ChangeLog | 44 ++++++++++++++++++++++++++++
include/time.h | 39 +++++++++++++------------
posix/bits/types.h | 9 ++++--
time/mktime-internal.h | 79 +++++++++++++++++++++++++++++++++++++++++++++++++-
time/mktime.c | 71 ++++++++++++++++++++++++++++-----------------
time/timegm.c | 32 +++++++++++++++++---
6 files changed, 220 insertions(+), 54 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index b2da915..d30639a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,47 @@
+2019-04-30 Paul Eggert <eggert@cs.ucla.edu>
+
+ Make mktime etc. compatible with __time64_t
+ Keep these functions compatible with Gnulib while adding
+ __time64_t support. The basic idea is to move private API
+ declarations from include/time.h to time/mktime-internal.h, since
+ the former file cannot easily be shared with Gnulib whereas the
+ latter can.
+ Also, do some other minor cleanup while in the neighborhood.
+ * include/time.h: Include stdbool.h, time/mktime-internal.h.
+ (__mktime_internal): Move this prototype to time/mktime-internal.h,
+ since Gnulib needs it.
+ (__localtime64_r, __gmtime64_r) [__TIMESIZE == 64]:
+ Move these macros to time/mktime-internal.h, since Gnulib needs them.
+ (__mktime64, __timegm64) [__TIMESIZE != 64]: New prototypes.
+ (in_time_t_range): New static function.
+ * posix/bits/types.h (__time64_t): Move to time/mktime-internal.h,
+ so that glibc users are not tempted to use __time64_t.
+ * time/mktime-internal.h: Rewrite so that it does both glibc
+ and Gnulib work. Include time.h if not _LIBC.
+ (mktime_offset_t) [!_LIBC]: Define for gnulib.
+ (__time64_t): New type or macro, moved here from
+ posix/bits/types.h.
+ (__gmtime64_r, __localtime64_r, __mktime64, __timegm64)
+ [!_LIBC || __TIMESIZE == 64): New macros, mostly moved here
+ from include/time.h.
+ (__gmtime_r, __localtime_r, __mktime_internal) [!_LIBC]:
+ New macros, taken from GNulib.
+ (__mktime_internal): New prototype, moved here from include/time.h.
+ * time/mktime.c (mktime_min, mktime_max, convert_time)
+ (ranged_convert, __mktime_internal, __mktime64):
+ * time/timegm.c (__timegm64):
+ Use __time64_t, not time_t.
+ * time/mktime.c: Stop worrying about whether time_t is floating-point.
+ (__mktime64) [! (_LIBC && __TIMESIZE != 64)]:
+ Rename from mktime.
+ (mktime) [_LIBC && __TIMESIZE != 64]: New function.
+ * time/timegm.c [!_LIBC]: Include libc-config.h, not config.h,
+ for libc_hidden_def.
+ Include errno.h.
+ (__timegm64) [! (_LIBC && __TIMESIZE != 64)]:
+ Rename from timegm.
+ (timegm) [_LIBC && __TIMESIZE != 64]: New function.
+
2019-04-30 Maciej W. Rozycki <macro@wdc.com>
[BZ #19444]
diff --git a/include/time.h b/include/time.h
index 61dd9e1..ac3163c 100644
--- a/include/time.h
+++ b/include/time.h
@@ -3,6 +3,8 @@
#ifndef _ISOMAC
# include <bits/types/locale_t.h>
+# include <stdbool.h>
+# include <time/mktime-internal.h>
extern __typeof (strftime_l) __strftime_l;
libc_hidden_proto (__strftime_l)
@@ -49,19 +51,11 @@ extern void __tzset_parse_tz (const char *tz) attribute_hidden;
extern void __tz_compute (__time64_t timer, struct tm *tm, int use_localtime)
__THROW attribute_hidden;
-/* Subroutine of `mktime'. Return the `time_t' representation of TP and
- normalize TP, given that a `struct tm *' maps to a `time_t' as performed
- by FUNC. Record next guess for localtime-gmtime offset in *OFFSET. */
-extern time_t __mktime_internal (struct tm *__tp,
- struct tm *(*__func) (const time_t *,
- struct tm *),
- long int *__offset) attribute_hidden;
-
#if __TIMESIZE == 64
# define __ctime64 ctime
#else
extern char *__ctime64 (const __time64_t *__timer) __THROW;
-libc_hidden_proto (__ctime64);
+libc_hidden_proto (__ctime64)
#endif
#if __TIMESIZE == 64
@@ -69,7 +63,7 @@ libc_hidden_proto (__ctime64);
#else
extern char *__ctime64_r (const __time64_t *__restrict __timer,
char *__restrict __buf) __THROW;
-libc_hidden_proto (__ctime64_r);
+libc_hidden_proto (__ctime64_r)
#endif
#if __TIMESIZE == 64
@@ -81,13 +75,13 @@ libc_hidden_proto (__localtime64)
extern struct tm *__localtime_r (const time_t *__timer,
struct tm *__tp) attribute_hidden;
-
-#if __TIMESIZE == 64
-# define __localtime64_r __localtime_r
-#else
+#if __TIMESIZE != 64
extern struct tm *__localtime64_r (const __time64_t *__timer,
struct tm *__tp);
libc_hidden_proto (__localtime64_r)
+
+extern __time64_t __mktime64 (struct tm *__tp) __THROW;
+libc_hidden_proto (__mktime64)
#endif
extern struct tm *__gmtime_r (const time_t *__restrict __timer,
@@ -99,14 +93,13 @@ libc_hidden_proto (__gmtime_r)
#else
extern struct tm *__gmtime64 (const __time64_t *__timer);
libc_hidden_proto (__gmtime64)
-#endif
-#if __TIMESIZE == 64
-# define __gmtime64_r __gmtime_r
-#else
extern struct tm *__gmtime64_r (const __time64_t *__restrict __timer,
struct tm *__restrict __tp);
-libc_hidden_proto (__gmtime64_r);
+libc_hidden_proto (__gmtime64_r)
+
+extern __time64_t __timegm64 (struct tm *__tp) __THROW;
+libc_hidden_proto (__timegm64)
#endif
/* Compute the `struct tm' representation of T,
@@ -155,5 +148,13 @@ extern double __difftime (time_t time1, time_t time0);
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
+/* Check whether T fits in time_t. */
+static inline bool
+in_time_t_range (__time64_t t)
+{
+ time_t s = t;
+ return s == t;
+}
+
#endif
#endif
diff --git a/posix/bits/types.h b/posix/bits/types.h
index 0de6c59..cb737ca 100644
--- a/posix/bits/types.h
+++ b/posix/bits/types.h
@@ -213,10 +213,13 @@ __STD_TYPE __U32_TYPE __socklen_t;
It is not currently necessary for this to be machine-specific. */
typedef int __sig_atomic_t;
-#if __TIMESIZE == 64
+/* Seconds since the Epoch, visible to user code when time_t is too
+ narrow only for consistency with the old way of widening too-narrow
+ types. User code should never use __time64_t. */
+#if __TIMESIZE == 64 && defined __LIBC
# define __time64_t __time_t
-#else
-__STD_TYPE __TIME64_T_TYPE __time64_t; /* Seconds since the Epoch. */
+#elif __TIMESIZE != 64
+__STD_TYPE __TIME64_T_TYPE __time64_t;
#endif
#undef __STD_TYPE
diff --git a/time/mktime-internal.h b/time/mktime-internal.h
index 6111c22..4cdeb9c 100644
--- a/time/mktime-internal.h
+++ b/time/mktime-internal.h
@@ -1,2 +1,79 @@
-/* Gnulib mktime-internal.h, tailored for glibc. */
+/* Internals of mktime and related functions
+ Copyright 2016-2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Paul Eggert <eggert@cs.ucla.edu>.
+
+ 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/>. */
+
+#ifndef _LIBC
+# include <time.h>
+#endif
+
+/* mktime_offset_t is a signed type wide enough to hold a UTC offset
+ in seconds, and used as part of the type of the offset-guess
+ argument to mktime_internal. In Glibc, it is always long int.
+ When in Gnulib, use time_t on platforms where time_t
+ is signed, to be compatible with platforms like BeOS that export
+ this implementation detail of mktime. On platforms where time_t is
+ unsigned, GNU and POSIX code can assume 'int' is at least 32 bits
+ which is wide enough for a UTC offset. */
+#ifdef _LIBC
typedef long int mktime_offset_t;
+#elif defined TIME_T_IS_SIGNED
+typedef time_t mktime_offset_t;
+#else
+typedef int mktime_offset_t;
+#endif
+
+/* The source code uses identifiers like __time64_t for glibc
+ timestamps that can contain 64-bit values even when time_t is only
+ 32 bits. These are just macros for the ordinary identifiers unless
+ compiling within glibc when time_t is 32 bits. */
+#if ! (defined _LIBC && __TIMESIZE != 64)
+# undef __time64_t
+# define __time64_t time_t
+# define __gmtime64_r __gmtime_r
+# define __localtime64_r __localtime_r
+# define __mktime64 mktime
+# define __timegm64 timegm
+#endif
+
+#ifndef _LIBC
+
+/* Although glibc source code uses leading underscores, Gnulib wants
+ ordinary names.
+
+ Portable standalone applications should supply a <time.h> that
+ declares a POSIX-compliant localtime_r, for the benefit of older
+ implementations that lack localtime_r or have a nonstandard one.
+ Similarly for gmtime_r. See the gnulib time_r module for one way
+ to implement this. */
+
+# undef __gmtime_r
+# undef __localtime_r
+# define __gmtime_r gmtime_r
+# define __localtime_r localtime_r
+
+# define __mktime_internal mktime_internal
+
+#endif
+
+/* Subroutine of mktime. Return the time_t representation of TP and
+ normalize TP, given that a struct tm * maps to a time_t as performed
+ by FUNC. Record next guess for localtime-gmtime offset in *OFFSET. */
+extern __time64_t __mktime_internal (struct tm *tp,
+ struct tm *(*func) (__time64_t const *,
+ struct tm *),
+ mktime_offset_t *offset) attribute_hidden;
diff --git a/time/mktime.c b/time/mktime.c
index 57efee9..8fe2f96 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -112,11 +112,11 @@ my_tzset (void)
added to them, and then with another timestamp added, without
worrying about overflow.
- Much of the code uses long_int to represent time_t values, to
- lessen the hassle of dealing with platforms where time_t is
+ Much of the code uses long_int to represent __time64_t values, to
+ lessen the hassle of dealing with platforms where __time64_t is
unsigned, and because long_int should suffice to represent all
- time_t values that mktime can generate even on platforms where
- time_t is excessively wide. */
+ __time64_t values that mktime can generate even on platforms where
+ __time64_t is wider than the int components of struct tm. */
#if INT_MAX <= LONG_MAX / 4 / 366 / 24 / 60 / 60
typedef long int long_int;
@@ -144,16 +144,15 @@ shr (long_int a, int b)
: a / (one << b) - (a % (one << b) < 0));
}
-/* Bounds for the intersection of time_t and long_int. */
+/* Bounds for the intersection of __time64_t and long_int. */
static long_int const mktime_min
- = ((TYPE_SIGNED (time_t) && TYPE_MINIMUM (time_t) < TYPE_MINIMUM (long_int))
- ? TYPE_MINIMUM (long_int) : TYPE_MINIMUM (time_t));
+ = ((TYPE_SIGNED (__time64_t)
+ && TYPE_MINIMUM (__time64_t) < TYPE_MINIMUM (long_int))
+ ? TYPE_MINIMUM (long_int) : TYPE_MINIMUM (__time64_t));
static long_int const mktime_max
- = (TYPE_MAXIMUM (long_int) < TYPE_MAXIMUM (time_t)
- ? TYPE_MAXIMUM (long_int) : TYPE_MAXIMUM (time_t));
-
-verify (TYPE_IS_INTEGER (time_t));
+ = (TYPE_MAXIMUM (long_int) < TYPE_MAXIMUM (__time64_t)
+ ? TYPE_MAXIMUM (long_int) : TYPE_MAXIMUM (__time64_t));
#define EPOCH_YEAR 1970
#define TM_YEAR_BASE 1900
@@ -252,23 +251,23 @@ tm_diff (long_int year, long_int yday, int hour, int min, int sec,
}
/* Use CONVERT to convert T to a struct tm value in *TM. T must be in
- range for time_t. Return TM if successful, NULL (setting errno) on
+ range for __time64_t. Return TM if successful, NULL (setting errno) on
failure. */
static struct tm *
-convert_time (struct tm *(*convert) (const time_t *, struct tm *),
+convert_time (struct tm *(*convert) (const __time64_t *, struct tm *),
long_int t, struct tm *tm)
{
- time_t x = t;
+ __time64_t x = t;
return convert (&x, tm);
}
/* Use CONVERT to convert *T to a broken down time in *TP.
If *T is out of range for conversion, adjust it so that
it is the nearest in-range value and then convert that.
- A value is in range if it fits in both time_t and long_int.
+ A value is in range if it fits in both __time64_t and long_int.
Return TP on success, NULL (setting errno) on failure. */
static struct tm *
-ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
+ranged_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
long_int *t, struct tm *tp)
{
long_int t1 = (*t < mktime_min ? mktime_min
@@ -310,7 +309,7 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
}
-/* Convert *TP to a time_t value, inverting
+/* Convert *TP to a __time64_t value, inverting
the monotonic and mostly-unit-linear conversion function CONVERT.
Use *OFFSET to keep track of a guess at the offset of the result,
compared to what the result would be for UTC without leap seconds.
@@ -318,9 +317,9 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *),
If successful, set *TP to the canonicalized struct tm;
otherwise leave *TP alone, return ((time_t) -1) and set errno.
This function is external because it is used also by timegm.c. */
-time_t
+__time64_t
__mktime_internal (struct tm *tp,
- struct tm *(*convert) (const time_t *, struct tm *),
+ struct tm *(*convert) (const __time64_t *, struct tm *),
mktime_offset_t *offset)
{
struct tm tm;
@@ -520,9 +519,9 @@ __mktime_internal (struct tm *tp,
#if defined _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS
-/* Convert *TP to a time_t value. */
-time_t
-mktime (struct tm *tp)
+/* Convert *TP to a __time64_t value. */
+__time64_t
+__mktime64 (struct tm *tp)
{
/* POSIX.1 8.1.1 requires that whenever mktime() is called, the
time zone names contained in the external variable 'tzname' shall
@@ -531,7 +530,7 @@ mktime (struct tm *tp)
# if defined _LIBC || NEED_MKTIME_WORKING
static mktime_offset_t localtime_offset;
- return __mktime_internal (tp, __localtime_r, &localtime_offset);
+ return __mktime_internal (tp, __localtime64_r, &localtime_offset);
# else
# undef mktime
return mktime (tp);
@@ -539,11 +538,29 @@ mktime (struct tm *tp)
}
#endif /* _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS */
-#ifdef weak_alias
-weak_alias (mktime, timelocal)
+#if defined _LIBC && __TIMESIZE != 64
+
+libc_hidden_def (__mktime64)
+
+time_t
+mktime (struct tm *tp)
+{
+ struct tm tm = *tp;
+ __time64_t t = __mktime64 (&tm);
+ if (in_time_t_range (t))
+ {
+ *tp = tm;
+ return t;
+ }
+ else
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+}
+
#endif
-#ifdef _LIBC
+weak_alias (mktime, timelocal)
libc_hidden_def (mktime)
libc_hidden_weak (timelocal)
-#endif
diff --git a/time/timegm.c b/time/timegm.c
index bfd36d0..bae0cee 100644
--- a/time/timegm.c
+++ b/time/timegm.c
@@ -18,17 +18,41 @@
<http://www.gnu.org/licenses/>. */
#ifndef _LIBC
-# include <config.h>
+# include <libc-config.h>
#endif
#include <time.h>
+#include <errno.h>
#include "mktime-internal.h"
-time_t
-timegm (struct tm *tmp)
+__time64_t
+__timegm64 (struct tm *tmp)
{
static mktime_offset_t gmtime_offset;
tmp->tm_isdst = 0;
- return __mktime_internal (tmp, __gmtime_r, &gmtime_offset);
+ return __mktime_internal (tmp, __gmtime64_r, &gmtime_offset);
}
+
+#if defined _LIBC && __TIMESIZE != 64
+
+libc_hidden_def (__timegm64)
+
+time_t
+timegm (struct tm *tmp)
+{
+ struct tm tm = *tmp;
+ __time64_t t = __timegm64 (&tm);
+ if (in_time_t_range (t))
+ {
+ *tmp = tm;
+ return t;
+ }
+ else
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
+}
+
+#endif