[v2,10/11] Make second argument of gettimeofday as 'void *'

  From: Zack Weinberg <zackw@panix.com>

Changes from previous version:

  - Remove warning for use of gettimeofday with a non-null __tz argument,
    the conditionals of making this work without false-positive seems quite 
    specific and fragile (gcc-only, optimized build, workaround for gcc
    bug).

--

Also make the public prototype of gettimeofday declare its second
argument with type "void *" unconditionally, consistent with POSIX.

It is also consistent with POSIX.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
 include/sys/time.h                            |  2 +-
 .../unix/sysv/linux/aarch64/gettimeofday.c    |  4 ++--
 .../unix/sysv/linux/powerpc/gettimeofday.c    |  4 ++--
 sysdeps/unix/sysv/linux/x86/gettimeofday.c    |  4 ++--
 time/gettimeofday.c                           |  4 ++--
 time/sys/time.h                               | 23 ++++++++++---------
 6 files changed, 21 insertions(+), 20 deletions(-)
  

On Fri, 25 Oct 2019 09:08:31 -0300
Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:

> From: Zack Weinberg <zackw@panix.com>
> 
> Changes from previous version:
> 
>   - Remove warning for use of gettimeofday with a non-null __tz
> argument, the conditionals of making this work without false-positive
> seems quite specific and fragile (gcc-only, optimized build,
> workaround for gcc bug).
> 
> --
> 
> Also make the public prototype of gettimeofday declare its second
> argument with type "void *" unconditionally, consistent with POSIX.
> 
> It is also consistent with POSIX.
> 
> Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
> powerpc64-linux-gnu, powerpc-linux-gnu, and aarch64-linux-gnu.
> 
> Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
>  include/sys/time.h                            |  2 +-
>  .../unix/sysv/linux/aarch64/gettimeofday.c    |  4 ++--
>  .../unix/sysv/linux/powerpc/gettimeofday.c    |  4 ++--
>  sysdeps/unix/sysv/linux/x86/gettimeofday.c    |  4 ++--
>  time/gettimeofday.c                           |  4 ++--
>  time/sys/time.h                               | 23
> ++++++++++--------- 6 files changed, 21 insertions(+), 20 deletions(-)
> 
> diff --git a/include/sys/time.h b/include/sys/time.h
> index 2bf4297e76..a461295c6a 100644
> --- a/include/sys/time.h
> +++ b/include/sys/time.h
> @@ -21,7 +21,7 @@
>  
>  # ifndef _ISOMAC
>  extern int __gettimeofday (struct timeval *__tv,
> -			   struct timezone *__tz);
> +			   void *__tz);
>  extern int __settimezone (const struct timezone *__tz)
>  	attribute_hidden;
>  extern int __adjtime (const struct timeval *__delta,
> diff --git a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c
> b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c index
> 075af3d0d3..7e772e05ce 100644 ---
> a/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c +++
> b/sysdeps/unix/sysv/linux/aarch64/gettimeofday.c @@ -31,7 +31,7 @@
>  /* Used as a fallback in the ifunc resolver if VDSO is not available
>     and for libc.so internal __gettimeofday calls.  */
>  static int
> -__gettimeofday_vsyscall (struct timeval *tv, struct timezone *tz)
> +__gettimeofday_vsyscall (struct timeval *restrict tv, void *restrict
> tz) {
>    if (__glibc_unlikely (tz != 0))
>      memset (tz, 0, sizeof *tz);
> @@ -50,7 +50,7 @@ libc_ifunc (__gettimeofday,
>  
>  #else
>  int
> -__gettimeofday (struct timeval *tv, struct timezone *tz)
> +__gettimeofday (struct timeval *restrict tv, void *restrict tz)
>  {
>    return __gettimeofday_vsyscall (tv, tz);
>  }
> diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c
> b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c index
> 02486dee3a..18d8f7cb7a 100644 ---
> a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c +++
> b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c @@ -24,7 +24,7 @@
>  #include <sysdep-vdso.h>
>  
>  static int
> -__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
> +__gettimeofday_syscall (struct timeval *restrict tv, void *restrict
> tz) {
>    if (__glibc_unlikely (tz != 0))
>      memset (tz, 0, sizeof *tz);
> @@ -46,7 +46,7 @@ libc_ifunc (__gettimeofday,
>  	    : (void *) __gettimeofday_syscall);
>  #else
>  int
> -__gettimeofday (struct timeval *tv, struct timezone *tz)
> +__gettimeofday (struct timeval *restrict tv, void *restrict tz)
>  {
>    return __gettimeofday_syscall (tv, tz);
>  }
> diff --git a/sysdeps/unix/sysv/linux/x86/gettimeofday.c
> b/sysdeps/unix/sysv/linux/x86/gettimeofday.c index
> cb20e358d8..190127d31e 100644 ---
> a/sysdeps/unix/sysv/linux/x86/gettimeofday.c +++
> b/sysdeps/unix/sysv/linux/x86/gettimeofday.c @@ -25,7 +25,7 @@
>  #include <sysdep-vdso.h>
>  
>  static int
> -__gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
> +__gettimeofday_syscall (struct timeval *restrict tv, void *restrict
> tz) {
>    if (__glibc_unlikely (tz != 0))
>      memset (tz, 0, sizeof *tz);
> @@ -45,7 +45,7 @@ libc_ifunc (__gettimeofday,
>  
>  #else
>  int
> -__gettimeofday (struct timeval *tv, struct timezone *tz)
> +__gettimeofday (struct timeval *restrict tv, void *restrict tz)
>  {
>    return __gettimeofday_syscall (tv, tz);
>  }
> diff --git a/time/gettimeofday.c b/time/gettimeofday.c
> index e8055b397d..ddaf46f481 100644
> --- a/time/gettimeofday.c
> +++ b/time/gettimeofday.c
> @@ -23,10 +23,10 @@
>     If *TZ is not NULL, clear it.
>     Returns 0 on success, -1 on errors.  */
>  int
> -___gettimeofday (struct timeval *tv, struct timezone *tz)
> +___gettimeofday (struct timeval *restrict tv, void *restrict tz)
>  {
>    if (__glibc_unlikely (tz != 0))
> -    memset (tz, 0, sizeof *tz);
> +    memset (tz, 0, sizeof (struct timezone));
>  
>    struct timespec ts;
>    if (__clock_gettime (CLOCK_REALTIME, &ts))
> diff --git a/time/sys/time.h b/time/sys/time.h
> index f8c946f94e..0473dae339 100644
> --- a/time/sys/time.h
> +++ b/time/sys/time.h
> @@ -54,23 +54,24 @@ struct timezone
>      int tz_minuteswest;		/* Minutes west of GMT.  */
>      int tz_dsttime;		/* Nonzero if DST is ever in
> effect.  */ };
> -
> -typedef struct timezone *__restrict __timezone_ptr_t;
> -#else
> -typedef void *__restrict __timezone_ptr_t;
>  #endif
>  
> -/* Get the current time of day and timezone information,
> -   putting it into *TV and *TZ.  If TZ is NULL, *TZ is not filled.
> -   Returns 0 on success, -1 on errors.
> -   NOTE: This form of timezone information is obsolete.
> -   Use the functions and variables declared in <time.h> instead.  */
> +/* Get the current time of day, putting it into *TV.
> +   If TZ is not null, *TZ must be a struct timezone, and both fields
> +   will be set to zero.
> +   Calling this function with a non-null TZ is obsolete;
> +   use localtime etc. instead.
> +   This function itself is semi-obsolete;
> +   most callers should use time or clock_gettime instead. */
>  extern int gettimeofday (struct timeval *__restrict __tv,
> -			 __timezone_ptr_t __tz) __THROW __nonnull
> ((1));
> +			 void *__restrict __tz) __THROW __nonnull
> ((1)); 
>  #ifdef __USE_MISC
>  /* Set the current time of day and timezone information.
> -   This call is restricted to the super-user.  */
> +   This call is restricted to the super-user.
> +   Setting the timezone in this way is obsolete, but we don't yet
> +   warn about it because it still has some uses for which there is
> +   no alternative.  */
>  extern int settimeofday (const struct timeval *__tv,
>  			 const struct timezone *__tz)
>       __THROW;

Reviewed-by: Lukasz Majewski <lukma@denx.de>


Best regards,

Lukasz Majewski

--

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