Re: [PATCH 1/2] Reinstate ftime and move define it for POSIX.1-2001 or older

[Lukasz Majewski <lukma@denx.de>]

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Hi Adhemerval,

> This patch revert "Move ftime to a compatibility symbol" (commit
> 14633d3e568eb9770a7e5046eff257113e0453fb).  The 'ftime' is handled
> similar to 'gets', where it is only exported if the program is built
> for POSIX.1-2001 or order (_POSIX_C_SOURCE=200112L).
> 
> Checked on x86_64-linux-gnu and i686-linux-gnu.
> ---
>  NEWS                                          |  6 +--
>  include/features.h                            | 10 ++++
>  include/sys/timeb.h                           |  1 +
>  .../unix/sysv/linux/riscv/rv32/libc.abilist   |  1 +
>  time/Makefile                                 |  5 +-
>  time/ftime.c                                  | 22 ++-------
>  time/sys/timeb.h                              | 48
> +++++++++++++++++++ time/tst-ftime.c                              |
> 40 ++++++---------- 8 files changed, 84 insertions(+), 49 deletions(-)
>  create mode 100644 include/sys/timeb.h
>  create mode 100644 time/sys/timeb.h
> 
> diff --git a/NEWS b/NEWS
> index 6eb577a669..6105eb0b3e 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -37,10 +37,8 @@ Deprecated and removed features, and other changes
> affecting compatibility: implementations from HWCAP subdirectories
> are no longer loaded. Instead, the default implementation is used.
>  
> -* The deprecated <sys/timeb.h> header and the ftime function have
> been
> -  removed.  To support old binaries, the ftime function continue to
> exist
> -  as a compatibility symbol (on those architectures which had it).
> All
> -  programs should use gettimeofday or clock_gettime instead.
> +* The deprecated ftime function is now only declared for
> POSIX.1-2001 or
> +  older standard.
>  
>  Changes to build and runtime requirements:
>  
> diff --git a/include/features.h b/include/features.h
> index f3e62d3362..aec149ed10 100644
> --- a/include/features.h
> +++ b/include/features.h
> @@ -143,6 +143,7 @@
>  #undef	__GLIBC_USE_ISOC2X
>  #undef	__GLIBC_USE_DEPRECATED_GETS
>  #undef	__GLIBC_USE_DEPRECATED_SCANF
> +#undef	__GLIBC_USE_DEPRECATED_FTIME
>  
>  /* Suppress kernel-name space pollution unless user expressedly asks
>     for it.  */
> @@ -438,6 +439,15 @@
>  # define __GLIBC_USE_DEPRECATED_SCANF 0
>  #endif
>  
> +/* The function 'ftime' appeared in Version 7 AT&T UNIX, it was
> marked
> +   as LEGACY on IEEE 1003.1-2004, and removed on IEEE 1003.1-2008.
> */ +#if (defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE - 0) <= 200112L)
> \
> +    || defined _XOPEN_SOURCE_EXTENDED
> +# define __GLIBC_USE_DEPRECATED_FTIME 1
> +#else
> +# define __GLIBC_USE_DEPRECATED_FTIME 0
> +#endif

Am I right that we only export the struct timeb when program, which
links to glibc indicates that some older POSIX standard will be used?

> +
>  /* Get definitions of __STDC_* predefined macros, if the compiler has
>     not preincluded this header automatically.  */
>  #include <stdc-predef.h>
> diff --git a/include/sys/timeb.h b/include/sys/timeb.h
> new file mode 100644
> index 0000000000..9f4509c35e
> --- /dev/null
> +++ b/include/sys/timeb.h
> @@ -0,0 +1 @@
> +#include <time/sys/timeb.h>
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
> b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist index
> e977715088..36aa34a5e7 100644 ---
> a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist +++
> b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist @@ -795,6 +795,7 @@
> GLIBC_2.33 fsync F GLIBC_2.33 ftell F
>  GLIBC_2.33 ftello F
>  GLIBC_2.33 ftello64 F
> +GLIBC_2.33 ftime F
>  GLIBC_2.33 ftok F
>  GLIBC_2.33 ftruncate F
>  GLIBC_2.33 ftruncate64 F
> diff --git a/time/Makefile b/time/Makefile
> index ab8fb3303b..a4fb13d6a3 100644
> --- a/time/Makefile
> +++ b/time/Makefile
> @@ -22,7 +22,7 @@ subdir	:= time
>  
>  include ../Makeconfig
>  
> -headers := time.h sys/time.h bits/time.h
> 	\ +headers := time.h sys/time.h sys/timeb.h
> bits/time.h			\ bits/types/clockid_t.h
> bits/types/clock_t.h			\
> bits/types/struct_itimerspec.h				\
> bits/types/struct_timespec.h bits/types/struct_timeval.h	\ @@
> -45,10 +45,9 @@ aux :=	    era alt_digit lc-time-cleanup
> tests	:= test_time clocktest tst-posixtz tst-strptime
> tst_wcsftime \ tst-getdate tst-mktime tst-mktime2 tst-ftime_l
> tst-strftime \ tst-mktime3 tst-strptime2 bug-asctime bug-asctime_r
> bug-mktime1 \
> -	   tst-strptime3 bug-getdate1 tst-strptime-whitespace \
> +	   tst-strptime3 bug-getdate1 tst-strptime-whitespace
> tst-ftime \ tst-tzname tst-y2039 bug-mktime4 tst-strftime2
> tst-strftime3 \ tst-clock tst-clock2 tst-clock_nanosleep tst-cpuclock1
> -tests-internal := tst-ftime
>  
>  include ../Rules
>  
> diff --git a/time/ftime.c b/time/ftime.c
> index be3295ef76..ec88d9963f 100644
> --- a/time/ftime.c
> +++ b/time/ftime.c
> @@ -16,23 +16,14 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -#include <shlib-compat.h>
> -
> -#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_33)
> -
> +#include <features.h>
> +#undef __GLIBC_USE_DEPRECATED_FTIME
> +#define __GLIBC_USE_DEPRECATED_FTIME 1
> +#include <sys/timeb.h>
>  #include <time.h>
>  
> -struct timeb
> -  {
> -    time_t time;		/* Seconds since epoch, as from
> `time'.  */
> -    unsigned short int millitm;	/* Additional milliseconds.
> */
> -    short int timezone;		/* Minutes west of GMT.  */
> -    short int dstflag;		/* Nonzero if Daylight Savings
> Time used.  */
> -  };
> -
>  int
> -attribute_compat_text_section
> -__ftime (struct timeb *timebuf)
> +ftime (struct timeb *timebuf)
>  {
>    struct timespec ts;
>    __clock_gettime (CLOCK_REALTIME, &ts);
> @@ -43,6 +34,3 @@ __ftime (struct timeb *timebuf)
>    timebuf->dstflag = 0;
>    return 0;
>  }
> -
> -compat_symbol (libc, __ftime, ftime, GLIBC_2_0);
> -#endif
> diff --git a/time/sys/timeb.h b/time/sys/timeb.h
> new file mode 100644
> index 0000000000..be7b46c178
> --- /dev/null
> +++ b/time/sys/timeb.h
> @@ -0,0 +1,48 @@
> +/* Copyright (C) 1994-2020 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef _SYS_TIMEB_H
> +#define _SYS_TIMEB_H	1
> +
> +#include <features.h>
> +
> +#include <bits/types/time_t.h>
> +
> +__BEGIN_DECLS
> +
> +#if __GLIBC_USE (DEPRECATED_FTIME)
> +
> +/* Structure returned by the `ftime' function.  */
> +
> +struct timeb
> +  {
> +    time_t time;		/* Seconds since epoch, as from
> `time'.  */
> +    unsigned short int millitm;	/* Additional milliseconds.
> */
> +    short int timezone;		/* Minutes west of GMT.  */
> +    short int dstflag;		/* Nonzero if Daylight Savings
> Time used.  */
> +  };
> +
> +/* Fill in TIMEBUF with information about the current time.  */
> +
> +extern int ftime (struct timeb *__timebuf)
> +  __nonnull ((1)) __attribute_deprecated__;
> +
> +#endif
> +
> +__END_DECLS
> +
> +#endif	/* sys/timeb.h */
> diff --git a/time/tst-ftime.c b/time/tst-ftime.c
> index 6978feb0f1..9d3c9e08ba 100644
> --- a/time/tst-ftime.c
> +++ b/time/tst-ftime.c
> @@ -16,24 +16,14 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> +#include <features.h>
> +#undef __GLIBC_USE_DEPRECATED_FTIME
> +#define __GLIBC_USE_DEPRECATED_FTIME 1
> +#include <sys/timeb.h>
> +#include <libc-diag.h>
>  
> -#include <shlib-compat.h>
> -#if TEST_COMPAT (libc, GLIBC_2_0, GLIBC_2_33)
> -#include <time.h>
>  #include <support/check.h>
>  
> -compat_symbol_reference (libc, ftime, ftime, GLIBC_2_0);
> -
> -struct timeb
> -  {
> -    time_t time;
> -    unsigned short int millitm;
> -    short int timezone;
> -    short int dstflag;
> -  };
> -
> -extern int ftime (struct timeb *__timebuf);
> -
>  static int
>  do_test (void)
>  {
> @@ -44,23 +34,23 @@ do_test (void)
>      {
>        prev = curr;
>  
> -      /* ftime was deprecated on 2.31 and removed on 2.33.  */
> +      /* ftime was deprecated on 2.31.  */
> +      DIAG_PUSH_NEEDS_COMMENT;
> +      DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
> +
>        TEST_COMPARE (ftime (&curr), 0);
> -      TEST_VERIFY_EXIT (curr.time >= prev.time);
> +
> +      DIAG_POP_NEEDS_COMMENT;
> +
> +      TEST_VERIFY (curr.time >= prev.time);
> +
>        if (curr.time == prev.time)
> -	TEST_VERIFY_EXIT (curr.millitm >= prev.millitm);
> +	TEST_VERIFY (curr.millitm >= prev.millitm);
>  
>        if (curr.time > prev.time)
>          sec ++;
>      }
>    return 0;
>  }
> -#else
> -static int
> -do_test (void)
> -{
> -  return EXIT_UNSUPPORTED;
> -}
> -#endif
>  
>  #include <support/test-driver.c>




Best regards,

Lukasz Majewski

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