[v2,1/2] Y2038: Add 64-bit time for all architectures
Commit Message
* Add macro __TIMESIZE equal to the bit size of time_t.
It equals the architecture __WORDSIZE except for x32
where it equals 64.
* Add type __time64_t which is always 64-bit. On 64-bit
architectures and on x32, it is #defined as time_t.
On other architectures, it has its own type.
* Replace all occurrences of internal_time_t with
__time64_t.
The __time64_t type is public so that the public time_t type
can be a typedef or #define of __time64_t when we switch the
public API to 64-bit time.
Also, provide a function (inline) to check if a __time64_t
value fits in a (possibly 32-bit) time_t. This is used when
a 32-bit-time wrapper calls a glibc function which returns
a __time64_t, so that the wrapper can detect times which
it cannot properly return to its caller, and can flag an
EOVERFLOW accordingly.
---
bits/timesize.h | 23 ++++++++++++
bits/timesizes.h | 37 ++++++++++++++++++++
include/sys/types.h | 1 +
include/time.h | 21 +++++++----
posix/bits/types.h | 8 +++++
stdlib/Makefile | 2 +-
sysdeps/unix/sysv/linux/x86/bits/timesizes.h | 32 +++++++++++++++++
sysdeps/x86/bits/timesize.h | 21 +++++++++++
time/tzfile.c | 18 +++++-----
9 files changed, 147 insertions(+), 16 deletions(-)
create mode 100644 bits/timesize.h
create mode 100644 bits/timesizes.h
create mode 100644 sysdeps/unix/sysv/linux/x86/bits/timesizes.h
create mode 100644 sysdeps/x86/bits/timesize.h
Comments
On Thu, 14 Jun 2018, Albert ARIBAUD (3ADEV) wrote:
> diff --git a/include/sys/types.h b/include/sys/types.h
> index 716732f4d4..107b0672ac 100644
> --- a/include/sys/types.h
> +++ b/include/sys/types.h
> @@ -1 +1,2 @@
> #include <posix/sys/types.h>
> +#include <bits/timesizes.h>
include/ wrappers should include the installed header and do nothing more
in the _ISOMAC case. For this header you shouldn't need any !_ISOMAC case
to include more, because sys/types.h includes bits/types.h and you've
already put a bits/timesizes.h include in there.
So no change to include/sys/types.h should be needed at all.
On 06/14/2018 06:51 AM, Albert ARIBAUD (3ADEV) wrote:
> +/* check whether a time64_t value fits in a time_t */
> +# if __TIMESIZE == 64
> +/* __time64_t is time_t, so it always fits_in_time_t */
> +# define fits_in_time_t(x) 1
> +# else
> +/* Not all __time64_t values can fit; check by type-casting */
> +static inline bool
> +fits_in_time_t (__time64_t t)
> +{
> + return t == (time_t) t;
> +}
> +# endif
Don't bother with the "#if". Just have the static function
unconditionally. It should generate zero instructions if time_t is 64 bits.
Hi Paul,
On Thu, 14 Jun 2018 09:56:03 -0700, Paul Eggert <eggert@cs.ucla.edu>
wrote :
> On 06/14/2018 06:51 AM, Albert ARIBAUD (3ADEV) wrote:
> > +/* check whether a time64_t value fits in a time_t */
> > +# if __TIMESIZE == 64
> > +/* __time64_t is time_t, so it always fits_in_time_t */
> > +# define fits_in_time_t(x) 1
> > +# else
> > +/* Not all __time64_t values can fit; check by type-casting */
> > +static inline bool
> > +fits_in_time_t (__time64_t t)
> > +{
> > + return t == (time_t) t;
> > +}
> > +# endif
>
> Don't bother with the "#if". Just have the static function
> unconditionally. It should generate zero instructions if time_t is 64 bits.
Done, thanks.
Cordialement,
Albert ARIBAUD
3ADEV
Hi Joseph,
On Thu, 14 Jun 2018 13:57:16 +0000, Joseph Myers
<joseph@codesourcery.com> wrote :
> On Thu, 14 Jun 2018, Albert ARIBAUD (3ADEV) wrote:
>
> > diff --git a/include/sys/types.h b/include/sys/types.h
> > index 716732f4d4..107b0672ac 100644
> > --- a/include/sys/types.h
> > +++ b/include/sys/types.h
> > @@ -1 +1,2 @@
> > #include <posix/sys/types.h>
> > +#include <bits/timesizes.h>
>
> include/ wrappers should include the installed header and do nothing more
> in the _ISOMAC case. For this header you shouldn't need any !_ISOMAC case
> to include more, because sys/types.h includes bits/types.h and you've
> already put a bits/timesizes.h include in there.
>
> So no change to include/sys/types.h should be needed at all.
Fixed, thanks.
Cordialement,
Albert ARIBAUD
3ADEV
On Thu, 2018-06-14 at 15:51 +0200, Albert ARIBAUD (3ADEV) wrote:
> * Add macro __TIMESIZE equal to the bit size of time_t.
> It equals the architecture __WORDSIZE except for x32
> where it equals 64.
>
> * Add type __time64_t which is always 64-bit. On 64-bit
> architectures and on x32, it is #defined as time_t.
> On other architectures, it has its own type.
[...]
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86/bits/timesizes.h
[...]
> +/* Both x86-64 and x32 use 64-bit time. */
> +#define __TIME64_T_TYPE __TIME_T_TYPE
[...]
But won't this file be used for regular 32-bit x86 (i386/i686) as well?
Ben.
On Mon, 2018-07-30 at 13:38 +0800, Ben Hutchings wrote:
> On Thu, 2018-06-14 at 15:51 +0200, Albert ARIBAUD (3ADEV) wrote:
> > * Add macro __TIMESIZE equal to the bit size of time_t.
> > It equals the architecture __WORDSIZE except for x32
> > where it equals 64.
> >
> > * Add type __time64_t which is always 64-bit. On 64-bit
> > architectures and on x32, it is #defined as time_t.
> > On other architectures, it has its own type.
>
> [...]
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/x86/bits/timesizes.h
>
> [...]
> > +/* Both x86-64 and x32 use 64-bit time. */
> > +#define __TIME64_T_TYPE __TIME_T_TYPE
>
> [...]
>
> But won't this file be used for regular 32-bit x86 (i386/i686) as well?
Never mind, I see this got fixed in v5.
Ben.
new file mode 100644
@@ -0,0 +1,23 @@
+/* Bit size of the time_t type at glibc build time, general case.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <bits/wordsize.h> // for __WORDSIZE
+
+/* Size in bits of the 'time_t' type; equals __WORDSIZE except for x32 */
+#define __TIMESIZE __WORDSIZE
new file mode 100644
@@ -0,0 +1,37 @@
+/* bits/timesizes.h -- underlying types for __time64_t. Generic version.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _BITS_TYPES_H
+# error "Never include <bits/timesizes.h> directly; use <sys/types.h> instead."
+#endif
+
+#ifndef _BITS_TIMESIZES_H
+#define _BITS_TIMESIZES_H 1
+
+/* See <bits/types.h> for the meaning of these macros. This file exists so
+ that <bits/types.h> need not vary across different GNU platforms. */
+
+#if __TIMESIZE == 64
+/* If we already have 64-bit time then use it */
+#define __TIME64_T_TYPE __TIME_T_TYPE
+#else
+/* Define a 64-bit type alongsize the 32-bit one */
+#define __TIME64_T_TYPE __SQUAD_TYPE
+#endif
+
+#endif /* bits/timesizes.h */
@@ -1 +1,2 @@
#include <posix/sys/types.h>
+#include <bits/timesizes.h>
@@ -3,6 +3,7 @@
#ifndef _ISOMAC
# include <bits/types/locale_t.h>
+# include <stdbool.h>
extern __typeof (strftime_l) __strftime_l;
libc_hidden_proto (__strftime_l)
@@ -26,10 +27,6 @@ extern __typeof (clock_getcpuclockid) __clock_getcpuclockid;
/* Now define the internal interfaces. */
struct tm;
-/* time_t variant for representing time zone data, independent of
- time_t. */
-typedef __int64_t internal_time_t;
-
/* Defined in mktime.c. */
extern const unsigned short int __mon_yday[2][13] attribute_hidden;
@@ -43,7 +40,7 @@ extern int __use_tzfile attribute_hidden;
extern void __tzfile_read (const char *file, size_t extra,
char **extrap) attribute_hidden;
-extern void __tzfile_compute (internal_time_t timer, int use_localtime,
+extern void __tzfile_compute (__time64_t timer, int use_localtime,
long int *leap_correct, int *leap_hit,
struct tm *tp) attribute_hidden;
extern void __tzfile_default (const char *std, const char *dst,
@@ -101,10 +98,22 @@ extern char * __strptime_internal (const char *rp, const char *fmt,
extern double __difftime (time_t time1, time_t time0);
-
/* Use in the clock_* functions. Size of the field representing the
actual clock ID. */
#define CLOCK_IDFIELD_SIZE 3
+/* check whether a time64_t value fits in a time_t */
+# if __TIMESIZE == 64
+/* __time64_t is time_t, so it always fits_in_time_t */
+# define fits_in_time_t(x) 1
+# else
+/* Not all __time64_t values can fit; check by type-casting */
+static inline bool
+fits_in_time_t (__time64_t t)
+{
+ return t == (time_t) t;
+}
+# endif
+
#endif
#endif
@@ -25,6 +25,7 @@
#include <features.h>
#include <bits/wordsize.h>
+#include <bits/timesize.h>
/* Convenience types. */
typedef unsigned char __u_char;
@@ -138,6 +139,7 @@ __extension__ typedef unsigned long long int __uintmax_t;
# error
#endif
#include <bits/typesizes.h> /* Defines __*_T_TYPE macros. */
+#include <bits/timesizes.h> /* Defines __TIME*_T_TYPE macros. */
__STD_TYPE __DEV_T_TYPE __dev_t; /* Type of device numbers. */
@@ -211,6 +213,12 @@ __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
+# define __time64_t time_t
+#else
+__STD_TYPE __TIME64_T_TYPE __time64_t; /* Seconds since the Epoch (_TIME_BITS==64). */
+#endif
+
#undef __STD_TYPE
#endif /* bits/types.h */
@@ -29,7 +29,7 @@ headers := stdlib.h bits/stdlib.h bits/stdlib-ldbl.h bits/stdlib-float.h \
ucontext.h sys/ucontext.h \
alloca.h fmtmsg.h \
bits/stdlib-bsearch.h sys/random.h bits/stdint-intn.h \
- bits/stdint-uintn.h
+ bits/stdint-uintn.h bits/timesizes.h bits/timesize.h \
routines := \
atof atoi atol atoll \
new file mode 100644
@@ -0,0 +1,32 @@
+/* bits/typesizes.h -- underlying types for __time64_t. Linux/x86-64 version.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _BITS_TYPES_H
+# error "Never include <bits/timesizes.h> directly; use <sys/types.h> instead."
+#endif
+
+#ifndef _BITS_TIMESIZES_H
+#define _BITS_TIMESIZES_H 1
+
+/* See <bits/types.h> for the meaning of these macros. This file exists so
+ that <bits/types.h> need not vary across different GNU platforms. */
+
+/* Both x86-64 and x32 use 64-bit time. */
+#define __TIME64_T_TYPE __TIME_T_TYPE
+
+#endif /* bits/timesizes.h */
new file mode 100644
@@ -0,0 +1,21 @@
+/* Bit size of the time_t type at glibc build time, x86-64 and x32 case.
+ Copyright (C) 2018 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+/* Both x86-64 and x32 use 64-bit time. */
+#define __TIMESIZE 64
@@ -44,12 +44,12 @@ struct ttinfo
struct leap
{
- internal_time_t transition; /* Time the transition takes effect. */
+ __time64_t transition; /* Time the transition takes effect. */
long int change; /* Seconds of correction to apply. */
};
static size_t num_transitions;
-libc_freeres_ptr (static internal_time_t *transitions);
+libc_freeres_ptr (static __time64_t *transitions);
static unsigned char *type_idxs;
static size_t num_types;
static struct ttinfo *types;
@@ -113,8 +113,8 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
size_t tzspec_len;
char *new = NULL;
- _Static_assert (sizeof (internal_time_t) == 8,
- "internal_time_t must be eight bytes");
+ _Static_assert (sizeof (__time64_t) == 8,
+ "__time64_t must be eight bytes");
__use_tzfile = 0;
@@ -220,9 +220,9 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
if (__builtin_expect (num_transitions
> ((SIZE_MAX - (__alignof__ (struct ttinfo) - 1))
- / (sizeof (internal_time_t) + 1)), 0))
+ / (sizeof (__time64_t) + 1)), 0))
goto lose;
- total_size = num_transitions * (sizeof (internal_time_t) + 1);
+ total_size = num_transitions * (sizeof (__time64_t) + 1);
total_size = ((total_size + __alignof__ (struct ttinfo) - 1)
& ~(__alignof__ (struct ttinfo) - 1));
types_idx = total_size;
@@ -279,7 +279,7 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
goto lose;
type_idxs = (unsigned char *) transitions + (num_transitions
- * sizeof (internal_time_t));
+ * sizeof (__time64_t));
types = (struct ttinfo *) ((char *) transitions + types_idx);
zone_names = (char *) types + num_types * sizeof (struct ttinfo);
leaps = (struct leap *) ((char *) transitions + leaps_idx);
@@ -580,7 +580,7 @@ __tzfile_default (const char *std, const char *dst,
}
void
-__tzfile_compute (internal_time_t timer, int use_localtime,
+__tzfile_compute (__time64_t timer, int use_localtime,
long int *leap_correct, int *leap_hit,
struct tm *tp)
{
@@ -669,7 +669,7 @@ __tzfile_compute (internal_time_t timer, int use_localtime,
initial search spot from it. Half of a gregorian year
has on average 365.2425 * 86400 / 2 = 15778476 seconds.
The value i can be truncated if size_t is smaller than
- internal_time_t, but this is harmless because it is just
+ __time64_t, but this is harmless because it is just
a guess. */
i = (transitions[num_transitions - 1] - timer) / 15778476;
if (i < num_transitions)