[PATCH v3] libio: Flush stream at freopen (BZ#21037)

[Andreas Schwab]

On Okt 01 2018, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:

> diff --git a/sysdeps/unix/sysv/linux/fd_to_filename.h b/sysdeps/unix/sysv/linux/fd_to_filename.h
> index 297716b0ae..62bc9916b0 100644
> --- a/sysdeps/unix/sysv/linux/fd_to_filename.h
> +++ b/sysdeps/unix/sysv/linux/fd_to_filename.h
> @@ -16,30 +16,20 @@
>     License along with the GNU C Library; if not, see
>     <http://www.gnu.org/licenses/>.  */
>  
> -#include <stdlib.h>
> -#include <string.h>
>  #include <sys/stat.h>
> -#include <_itoa.h>
> +
> +#define FD_TO_FILENAME_SIZE ((sizeof ("/proc/self/fd/") - 1) \
> +			     + (sizeof ("4294967295") - 1) + 1)
>  
>  static inline const char *
> -fd_to_filename (int fd)
> +fd_to_filename (unsigned int fd, char *buf)
>  {
> -  char *ret = malloc (30);
> -
> -  if (ret != NULL)
> -    {
> -      struct stat64 st;
> -
> -      *_fitoa_word (fd, __stpcpy (ret, "/proc/self/fd/"), 10, 0) = '\0';
> -
> -      /* We must make sure the file exists.  */
> -      if (__lxstat64 (_STAT_VER, ret, &st) < 0)
> -	{
> -	  /* /proc is not mounted or something else happened.  Don't
> -	     return the file name.  */
> -	  free (ret);
> -	  ret = NULL;
> -	}
> -    }
> -  return ret;
> +  *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
> +
> +  /* We must make sure the file exists.  */
> +  struct stat64 st;
> +  if (__lxstat64 (_STAT_VER, buf, &st) < 0)
> +    /* /proc is not mounted or something else happened.  */
> +    return NULL;
> +  return buf;
>  }

In file included from freopen.c:33:
../sysdeps/unix/sysv/linux/fd_to_filename.h: In function ‘fd_to_filename’:
../sysdeps/unix/sysv/linux/fd_to_filename.h:27:4: error: implicit declaration of function ‘_fitoa_word’ [-Werror=implicit-function-declaration]
   *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
    ^~~~~~~~~~~
../sysdeps/unix/sysv/linux/fd_to_filename.h:27:21: error: implicit declaration of function ‘__stpcpy’; did you mean ‘__setpgid’? [-Werror=implicit-function-declaration]
   *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
                     ^~~~~~~~
                     __setpgid
../sysdeps/unix/sysv/linux/fd_to_filename.h:27:3: error: invalid type argument of unary ‘*’ (have ‘int’)
   *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[2]: *** [../o-iterator.mk:9: /suse/schwab/src/libc/n-riscv64/libio/freopen.o] Error 1

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."