1 files changed, 76 insertions, 0 deletions

diff --git a/gl/freading.c b/gl/freading.c
new file mode 100644
index 00000000..be4f561a
--- /dev/null
+++ b/gl/freading.c
@@ -0,0 +1,76 @@
+/* Retrieve information about a FILE stream.
+   Copyright (C) 2007-2021 Free Software Foundation, Inc.
+
+   This file 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.
+
+   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "freading.h"
+
+#include "stdio-impl.h"
+
+/* Don't use glibc's __freading function in glibc < 2.7, see
+   <https://sourceware.org/bugzilla/show_bug.cgi?id=4359>  */
+#if !(HAVE___FREADING && (!defined __GLIBC__ || defined __UCLIBC__ || __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7)))
+
+bool
+freading (FILE *fp)
+{
+  /* Most systems provide FILE as a struct and the necessary bitmask in
+     <stdio.h>, because they need it for implementing getc() and putc() as
+     fast macros.  */
+# if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
+  /* GNU libc, BeOS, Haiku, Linux libc5 */
+  return ((fp->_flags & _IO_NO_WRITES) != 0
+          || ((fp->_flags & (_IO_NO_READS | _IO_CURRENTLY_PUTTING)) == 0
+              && fp->_IO_read_base != NULL));
+# elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
+  /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin < 1.7.34, Minix 3, Android */
+  return (fp_->_flags & __SRD) != 0;
+# elif defined __EMX__               /* emx+gcc */
+  return (fp->_flags & _IOREAD) != 0;
+# elif defined __minix               /* Minix */
+  return (fp->_flags & _IOREADING) != 0;
+# elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
+#  if defined __sun                  /* Solaris */
+  return (fp_->_flag & _IOREAD) != 0 && (fp_->_flag & _IOWRT) == 0;
+#  else
+  return (fp_->_flag & _IOREAD) != 0;
+#  endif
+# elif defined __UCLIBC__            /* uClibc */
+  return (fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) != 0;
+# elif defined __QNX__               /* QNX */
+  return ((fp->_Mode & 0x2 /* _MOPENW */) == 0
+          || (fp->_Mode & 0x1000 /* _MREAD */) != 0);
+# elif defined __MINT__              /* Atari FreeMiNT */
+  if (!fp->__mode.__write)
+    return 1;
+  if (!fp->__mode.__read)
+    return 0;
+#  ifdef _IO_CURRENTLY_GETTING /* Flag added on 2009-02-28 */
+  return (fp->__flags & _IO_CURRENTLY_GETTING) != 0;
+#  else
+  return (fp->__buffer < fp->__get_limit /*|| fp->__bufp == fp->__put_limit ??*/);
+#  endif
+# elif defined EPLAN9                /* Plan9 */
+  if (fp->state == 0 /* CLOSED */ || fp->state == 4 /* WR */)
+    return 0;
+  return (fp->state == 3 /* RD */ && (fp->bufl == 0 || fp->rp < fp->wp));
+# else
+#  error "Please port gnulib freading.c to your platform!"
+# endif
+}
+
+#endif