Line data    Source code

       1             : /* Set the error indicator of a stream.
       2             :    Copyright (C) 2007-2025 Free Software Foundation, Inc.
       3             : 
       4             :    This file is free software: you can redistribute it and/or modify
       5             :    it under the terms of the GNU Lesser General Public License as
       6             :    published by the Free Software Foundation; either version 2.1 of the
       7             :    License, or (at your option) any later version.
       8             : 
       9             :    This file is distributed in the hope that it will be useful,
      10             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12             :    GNU Lesser General Public License for more details.
      13             : 
      14             :    You should have received a copy of the GNU Lesser General Public License
      15             :    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16             : 
      17             : #include <config.h>
      18             : 
      19             : /* Specification.  */
      20             : #include "fseterr.h"
      21             : 
      22             : #include <errno.h>
      23             : 
      24             : #include "stdio-impl.h"
      25             : 
      26             : /* This file is not used on systems that have the __fseterr function,
      27             :    namely OpenBSD >= 7.6, musl libc, Haiku >= hrev58760.  */
      28             : 
      29             : void
      30           0 : fseterr (FILE *fp)
      31             : {
      32             :   /* Most systems provide FILE as a struct and the necessary bitmask in
      33             :      <stdio.h>, because they need it for implementing getc() and putc() as
      34             :      fast macros.  */
      35             : #if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
      36             :   /* GNU libc, BeOS, Haiku, Linux libc5 */
      37           0 :   fp->_flags |= _IO_ERR_SEEN;
      38             : #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
      39             :   /* FreeBSD, NetBSD, OpenBSD < 7.6, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
      40             :   fp_->_flags |= __SERR;
      41             : #elif defined __EMX__               /* emx+gcc */
      42             :   fp->_flags |= _IOERR;
      43             : #elif defined __minix               /* Minix */
      44             :   fp->_flags |= _IOERR;
      45             : #elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
      46             :   fp_->_flag |= _IOERR;
      47             : #elif defined __UCLIBC__            /* uClibc */
      48             :   fp->__modeflags |= __FLAG_ERROR;
      49             : #elif defined __QNX__               /* QNX */
      50             :   fp->_Mode |= 0x200 /* _MERR */;
      51             : #elif defined __MINT__              /* Atari FreeMiNT */
      52             :   fp->__error = 1;
      53             : #elif defined EPLAN9                /* Plan9 */
      54             :   if (fp->state != 0 /* CLOSED */)
      55             :     fp->state = 5 /* ERR */;
      56             : #elif 0                             /* unknown  */
      57             :   /* Portable fallback, based on an idea by Rich Felker.
      58             :      Wow! 6 system calls for something that is just a bit operation!
      59             :      Not activated on any system, because there is no way to repair FP when
      60             :      the sequence of system calls fails, and library code should not call
      61             :      abort().  */
      62             :   int saved_errno;
      63             :   int fd;
      64             :   int fd2;
      65             : 
      66             :   saved_errno = errno;
      67             :   fflush (fp);
      68             :   fd = fileno (fp);
      69             :   fd2 = dup (fd);
      70             :   if (fd2 >= 0)
      71             :     {
      72             :       close (fd);
      73             :       fputc ('\0', fp); /* This should set the error indicator.  */
      74             :       fflush (fp);      /* Or this.  */
      75             :       if (dup2 (fd2, fd) < 0)
      76             :         /* Whee... we botched the stream and now cannot restore it!  */
      77             :         abort ();
      78             :       close (fd2);
      79             :     }
      80             :   errno = saved_errno;
      81             : #else
      82             :  #error "Please port gnulib fseterr.c to your platform! Look at the definitions of ferror and clearerr on your system, then report this to bug-gnulib."
      83             : #endif
      84           0 : }