Define CLOCKS_PER_SEC type to the type clock_t
Commit Message
C99 specifies that CLOCKS_PER_SEC is a constant expression with the type
clock_t. This patch adds a generic <bits/time2.h> to define CLOCKS_PER_SEC
and provides the Linux/x86-64 version of <bits/time2.h> to support x32.
Tested on i686, x32 and x86-64. OK to install?
Thanks.
H.J.
---
[BZ #17797]
* bits/time2.h: New file.
* sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
* bits/time.h: Include <bits/time2.h>.
(CLOCKS_PER_SEC): Removed.
* sysdeps/unix/sysv/linux/bits/time.h: Likewise.
* time/Makefile (headers): Add bits/time2.h.
* time/clocktest.c (main): Replace %ld with %jd and cast to
intmax_t.
---
ChangeLog | 12 ++++++++++
bits/time.h | 9 ++------
bits/time2.h | 34 ++++++++++++++++++++++++++++
sysdeps/unix/sysv/linux/bits/time.h | 9 ++------
sysdeps/unix/sysv/linux/x86/bits/time2.h | 38 ++++++++++++++++++++++++++++++++
time/Makefile | 2 +-
time/clocktest.c | 4 ++--
7 files changed, 91 insertions(+), 17 deletions(-)
create mode 100644 bits/time2.h
create mode 100644 sysdeps/unix/sysv/linux/x86/bits/time2.h
Comments
On 01/05/2015 12:46 PM, H.J. Lu wrote:
> C99 specifies that CLOCKS_PER_SEC is a constant expression
A minor point (mostly for comments): CLOCKS_PER_SEC needn't be a
constant expression. Even POSIX doesn't require that: on the contrary,
it explicitly warns you that it might not be a constant expression, even
though it must evaluate to 1000000.
> + * bits/time2.h: New file.
> + * sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
Wouldn't it be simpler and clearer to replace "# define CLOCKS_PER_SEC
1000000l" with "# define CLOCKS_PER_SEC ((clock_t) 1000000)"? That way,
one wouldn't need all these other little files running around.
On Mon, Jan 5, 2015 at 2:32 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
> On 01/05/2015 12:46 PM, H.J. Lu wrote:
>>
>> C99 specifies that CLOCKS_PER_SEC is a constant expression
>
>
> A minor point (mostly for comments): CLOCKS_PER_SEC needn't be a constant
> expression. Even POSIX doesn't require that: on the contrary, it explicitly
> warns you that it might not be a constant expression, even though it must
> evaluate to 1000000.
>
>> + * bits/time2.h: New file.
>> + * sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
>
>
> Wouldn't it be simpler and clearer to replace "# define CLOCKS_PER_SEC
> 1000000l" with "# define CLOCKS_PER_SEC ((clock_t) 1000000)"? That way, one
> wouldn't need all these other little files running around.
My copy of C99 has
---
CLOCKS_PER_SEC
which expands to a constant expression with type clock_t (described below)
that is the number per second of the value returned by the clock function.
---
Has it been changed?
On Mon, Jan 5, 2015 at 2:45 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Mon, Jan 5, 2015 at 2:32 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
>> On 01/05/2015 12:46 PM, H.J. Lu wrote:
>>>
>>> C99 specifies that CLOCKS_PER_SEC is a constant expression
>>
>>
>> A minor point (mostly for comments): CLOCKS_PER_SEC needn't be a constant
>> expression. Even POSIX doesn't require that: on the contrary, it explicitly
>> warns you that it might not be a constant expression, even though it must
>> evaluate to 1000000.
>>
>>> + * bits/time2.h: New file.
>>> + * sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
>>
>>
>> Wouldn't it be simpler and clearer to replace "# define CLOCKS_PER_SEC
>> 1000000l" with "# define CLOCKS_PER_SEC ((clock_t) 1000000)"? That way, one
>> wouldn't need all these other little files running around.
>
> My copy of C99 has
>
> ---
> CLOCKS_PER_SEC
>
> which expands to a constant expression with type clock_t (described below)
> that is the number per second of the value returned by the clock function.
> ---
>
> Has it been changed?
Yes, it does:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_281.htm
I will update my patch.
Thanks.
@@ -1,3 +1,15 @@
+2015-01-05 H.J. Lu <hongjiu.lu@intel.com>
+
+ [BZ #17797]
+ * bits/time2.h: New file.
+ * sysdeps/unix/sysv/linux/x86/bits/time2.h: Likewise.
+ * bits/time.h: Include <bits/time2.h>.
+ (CLOCKS_PER_SEC): Removed.
+ * sysdeps/unix/sysv/linux/bits/time.h: Likewise.
+ * time/Makefile (headers): Add bits/time2.h.
+ * time/clocktest.c (main): Replace %ld with %jd and cast to
+ intmax_t.
+
2015-01-05 Joseph Myers <joseph@codesourcery.com>
[BZ #17796]
@@ -24,13 +24,8 @@
# ifndef _BITS_TIME_H
# define _BITS_TIME_H 1
-/* ISO/IEC 9899:1990 7.12.1: <time.h>
- The macro `CLOCKS_PER_SEC' is the number per second of the value
- returned by the `clock' function. */
-/* CAE XSH, Issue 4, Version 2: <time.h>
- The value of CLOCKS_PER_SEC is required to be 1 million on all
- XSI-conformant systems. */
-# define CLOCKS_PER_SEC 1000000l
+/* Get CLOCKS_PER_SEC. */
+# include <bits/time2.h>
# if !defined __STRICT_ANSI__ && !defined __USE_XOPEN2K
/* Even though CLOCKS_PER_SEC has such a strange value CLK_TCK
new file mode 100644
@@ -0,0 +1,34 @@
+/* CLOCKS_PER_SEC. Generic version.
+ Copyright (C) 2015 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/>. */
+
+/*
+ * Never include this file directly; use <time.h> instead.
+ */
+
+#ifndef _BITS_TIME_H
+# error "Never include <bits/time2.h> directly; use <time.h> instead."
+#endif
+
+/* ISO/IEC 9899:1999 7.23: Date and time <time.h>
+ The macro `CLOCKS_PER_SEC' is a constant expression with type `clock_t'
+ that is the number per second of the value returned by the `clock'
+ function. */
+/* CAE XSH, Issue 4, Version 2: <time.h>
+ The value of CLOCKS_PER_SEC is required to be 1 million on all
+ XSI-conformant systems. */
+#define CLOCKS_PER_SEC 1000000l
@@ -39,13 +39,8 @@ struct timeval
# ifndef _BITS_TIME_H
# define _BITS_TIME_H 1
-/* ISO/IEC 9899:1990 7.12.1: <time.h>
- The macro `CLOCKS_PER_SEC' is the number per second of the value
- returned by the `clock' function. */
-/* CAE XSH, Issue 4, Version 2: <time.h>
- The value of CLOCKS_PER_SEC is required to be 1 million on all
- XSI-conformant systems. */
-# define CLOCKS_PER_SEC 1000000l
+/* Get CLOCKS_PER_SEC. */
+# include <bits/time2.h>
# if (!defined __STRICT_ANSI__ || defined __USE_POSIX) \
&& !defined __USE_XOPEN2K
new file mode 100644
@@ -0,0 +1,38 @@
+/* CLOCKS_PER_SEC. Linux/x86-64 version.
+ Copyright (C) 2015 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/>. */
+
+/*
+ * Never include this file directly; use <time.h> instead.
+ */
+
+#ifndef _BITS_TIME_H
+# error "Never include <bits/time2.h> directly; use <time.h> instead."
+#endif
+
+/* ISO/IEC 9899:1999 7.23: Date and time <time.h>
+ The macro `CLOCKS_PER_SEC' is a constant expression with type `clock_t'
+ that is the number per second of the value returned by the `clock'
+ function. */
+/* CAE XSH, Issue 4, Version 2: <time.h>
+ The value of CLOCKS_PER_SEC is required to be 1 million on all
+ XSI-conformant systems. */
+#if defined __x86_64__ && defined __ILP32__
+# define CLOCKS_PER_SEC 1000000ll
+#else
+# define CLOCKS_PER_SEC 1000000l
+#endif
@@ -22,7 +22,7 @@ subdir := time
include ../Makeconfig
-headers := time.h sys/time.h sys/timeb.h bits/time.h
+headers := time.h sys/time.h sys/timeb.h bits/time.h bits/time2.h
routines := offtime asctime clock ctime ctime_r difftime \
gmtime localtime mktime time \
@@ -30,7 +30,7 @@ main (int argc, char ** argv)
printf ("%jd clock ticks per second (start=%jd,stop=%jd)\n",
(intmax_t) (stop - start), (intmax_t) start, (intmax_t) stop);
- printf ("CLOCKS_PER_SEC=%ld, sysconf(_SC_CLK_TCK)=%ld\n",
- CLOCKS_PER_SEC, sysconf(_SC_CLK_TCK));
+ printf ("CLOCKS_PER_SEC=%jd, sysconf(_SC_CLK_TCK)=%ld\n",
+ (intmax_t) CLOCKS_PER_SEC, sysconf(_SC_CLK_TCK));
return 0;
}