maint/gnulib/lib/fpurge.c

/* */
This source file includes following definitions.
fpurge
   1 /* Flushing buffers of a FILE stream.
   2    Copyright (C) 2007-2021 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 <stdio.h>
  21 
  22 #if HAVE___FPURGE                   /* glibc >= 2.2, Haiku, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.10, Android API >= 23, musl libc */
  23 # if HAVE_STDIO_EXT_H
  24 #  include <stdio_ext.h>
  25 # endif
  26 #endif
  27 #include <stdlib.h>
  28 
  29 #include "stdio-impl.h"
  30 
  31 int
  32 fpurge (FILE *fp)
     /*  */
  33 {
  34 #if HAVE___FPURGE                   /* glibc >= 2.2, Haiku, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.10, Android API >= 23, musl libc */
  35 
  36   __fpurge (fp);
  37   /* The __fpurge function does not have a return value.  */
  38   return 0;
  39 
  40 #elif HAVE_FPURGE                   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin >= 1.7 */
  41 
  42   /* Call the system's fpurge function.  */
  43 # undef fpurge
  44 # if !HAVE_DECL_FPURGE
  45   extern int fpurge (FILE *);
  46 # endif
  47   int result = fpurge (fp);
  48 # if defined __sferror || defined __DragonFly__ || defined __ANDROID__
  49   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
  50   if (result == 0)
  51     /* Correct the invariants that fpurge broke.
  52        <stdio.h> on BSD systems says:
  53          "The following always hold: if _flags & __SRD, _w is 0."
  54        If this invariant is not fulfilled and the stream is read-write but
  55        currently reading, subsequent putc or fputc calls will write directly
  56        into the buffer, although they shouldn't be allowed to.  */
  57     if ((fp_->_flags & __SRD) != 0)
  58       fp_->_w = 0;
  59 # endif
  60   return result;
  61 
  62 #else
  63 
  64   /* Most systems provide FILE as a struct and the necessary bitmask in
  65      <stdio.h>, because they need it for implementing getc() and putc() as
  66      fast macros.  */
  67 # if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
  68   /* GNU libc, BeOS, Haiku, Linux libc5 */
  69   fp->_IO_read_end = fp->_IO_read_ptr;
  70   fp->_IO_write_ptr = fp->_IO_write_base;
  71   /* Avoid memory leak when there is an active ungetc buffer.  */
  72   if (fp->_IO_save_base != NULL)
  73     {
  74       free (fp->_IO_save_base);
  75       fp->_IO_save_base = NULL;
  76     }
  77   return 0;
  78 # elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
  79   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
  80   fp_->_p = fp_->_bf._base;
  81   fp_->_r = 0;
  82   fp_->_w = ((fp_->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */
  83              ? fp_->_bf._size
  84              : 0);
  85   /* Avoid memory leak when there is an active ungetc buffer.  */
  86   if (fp_ub._base != NULL)
  87     {
  88       if (fp_ub._base != fp_->_ubuf)
  89         free (fp_ub._base);
  90       fp_ub._base = NULL;
  91     }
  92   return 0;
  93 # elif defined __EMX__              /* emx+gcc */
  94   fp->_ptr = fp->_buffer;
  95   fp->_rcount = 0;
  96   fp->_wcount = 0;
  97   fp->_ungetc_count = 0;
  98   return 0;
  99 # elif defined __minix              /* Minix */
 100   fp->_ptr = fp->_buf;
 101   if (fp->_ptr != NULL)
 102     fp->_count = 0;
 103   return 0;
 104 # elif defined _IOERR               /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
 105   fp_->_ptr = fp_->_base;
 106   if (fp_->_ptr != NULL)
 107     fp_->_cnt = 0;
 108   return 0;
 109 # elif defined __UCLIBC__           /* uClibc */
 110 #  ifdef __STDIO_BUFFERS
 111   if (fp->__modeflags & __FLAG_WRITING)
 112     fp->__bufpos = fp->__bufstart;
 113   else if (fp->__modeflags & (__FLAG_READONLY | __FLAG_READING))
 114     fp->__bufpos = fp->__bufread;
 115 #  endif
 116   return 0;
 117 # elif defined __QNX__              /* QNX */
 118   fp->_Rback = fp->_Back + sizeof (fp->_Back);
 119   fp->_Rsave = NULL;
 120   if (fp->_Mode & 0x2000 /* _MWRITE */)
 121     /* fp->_Buf <= fp->_Next <= fp->_Wend */
 122     fp->_Next = fp->_Buf;
 123   else
 124     /* fp->_Buf <= fp->_Next <= fp->_Rend */
 125     fp->_Rend = fp->_Next;
 126   return 0;
 127 # elif defined __MINT__             /* Atari FreeMiNT */
 128   if (fp->__pushed_back)
 129     {
 130       fp->__bufp = fp->__pushback_bufp;
 131       fp->__pushed_back = 0;
 132     }
 133   /* Preserve the current file position.  */
 134   if (fp->__target != -1)
 135     fp->__target += fp->__bufp - fp->__buffer;
 136   fp->__bufp = fp->__buffer;
 137   /* Nothing in the buffer, next getc is nontrivial.  */
 138   fp->__get_limit = fp->__bufp;
 139   /* Nothing in the buffer, next putc is nontrivial.  */
 140   fp->__put_limit = fp->__buffer;
 141   return 0;
 142 # elif defined EPLAN9               /* Plan9 */
 143   fp->rp = fp->wp = fp->lp = fp->buf;
 144   return 0;
 145 # else
 146 #  error "Please port gnulib fpurge.c to your platform! Look at the definitions of fflush, setvbuf and ungetc on your system, then report this to bug-gnulib."
 147 # endif
 148 
 149 #endif
 150 }
/* */
root/maint/gnulib/lib/fpurge.c

DEFINITIONS
