1 | /* Set the error indicator of a stream. |
2 | Copyright (C) 2007-2019 Free Software Foundation, Inc. |
3 | |
4 | This program is free software: you can redistribute it and/or modify |
5 | it under the terms of the GNU General Public License as published by |
6 | the Free Software Foundation; either version 3 of the License, or |
7 | (at your option) any later version. |
8 | |
9 | This program 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 General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU 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 musl libc. */ |
28 | |
29 | void |
30 | 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 | fp->_flags |= _IO_ERR_SEEN; |
38 | #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__ |
39 | /* FreeBSD, NetBSD, OpenBSD, 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, 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 | } |
85 | |