libio/strfile.h

   1 /* Copyright (C) 1993-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.
  17
  18    As a special exception, if you link the code in this file with
  19    files compiled with a GNU compiler to produce an executable,
  20    that does not cause the resulting executable to be covered by
  21    the GNU Lesser General Public License.  This exception does not
  22    however invalidate any other reasons why the executable file
  23    might be covered by the GNU Lesser General Public License.
  24    This exception applies to code released by its copyright holders
  25    in files containing the exception.  */
  26
  27 #ifndef STRFILE_H_
  28 #define STRFILE_H_
  29
  30 #include "libioP.h"
  31
  32 typedef void *(*_IO_alloc_type) (size_t);
  33 typedef void (*_IO_free_type) (void*);
  34
  35 struct _IO_str_fields
  36 {
  37   /* These members are preserved for ABI compatibility.  The glibc
  38      implementation always calls malloc/free for user buffers if
  39      _IO_USER_BUF or _IO_FLAGS2_USER_WBUF are not set.  */
  40   _IO_alloc_type _allocate_buffer_unused;
  41   _IO_free_type _free_buffer_unused;
  42 };
  43
  44 /* This is needed for the Irix6 N32 ABI, which has a 64 bit off_t type,
  45    but a 32 bit pointer type.  In this case, we get 4 bytes of padding
  46    after the vtable pointer.  Putting them in a structure together solves
  47    this problem.  */
  48
  49 struct _IO_streambuf
  50 {
  51   FILE _f;
  52   const struct _IO_jump_t *vtable;
  53 };
  54
  55 typedef struct _IO_strfile_
  56 {
  57   struct _IO_streambuf _sbf;
  58   struct _IO_str_fields _s;
  59 } _IO_strfile;
  60
  61 /* frozen: set when the program has requested that the array object not
  62    be altered, reallocated, or freed. */
  63 #define _IO_STR_FROZEN(FP) ((FP)->_f._flags & _IO_USER_BUF)
  64
  65 typedef struct
  66 {
  67   _IO_strfile f;
  68   /* This is used for the characters which do not fit in the buffer
  69      provided by the user.  */
  70   char overflow_buf[64];
  71 } _IO_strnfile;
  72
  73 typedef struct
  74 {
  75   _IO_strfile f;
  76   /* This is used for the characters which do not fit in the buffer
  77      provided by the user.  */
  78   wchar_t overflow_buf[64];
  79 } _IO_wstrnfile;
  80
  81 /* Initialize an _IO_strfile SF to read from narrow string STRING, and
  82    return the corresponding FILE object.  It is not necessary to fclose
  83    the FILE when it is no longer needed.  */
  84 static inline FILE *
  85 _IO_strfile_read (_IO_strfile *sf, const char *string)
  86 {
  87   sf->_sbf._f._lock = NULL;
  88   _IO_no_init (&sf->_sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
  89   _IO_JUMPS (&sf->_sbf) = &_IO_str_jumps;
  90   _IO_str_init_static_internal (sf, (char*)string, 0, NULL);
  91   return &sf->_sbf._f;
  92 }
  93
  94 /* Initialize an _IO_strfile SF and _IO_wide_data WD to read from wide
  95    string STRING, and return the corresponding FILE object.  It is not
  96    necessary to fclose the FILE when it is no longer needed.  */
  97 static inline FILE *
  98 _IO_strfile_readw (_IO_strfile *sf, struct _IO_wide_data *wd,
  99                    const wchar_t *string)
 100 {
 101   sf->_sbf._f._lock = NULL;
 102   _IO_no_init (&sf->_sbf._f, _IO_USER_LOCK, 0, wd, &_IO_wstr_jumps);
 103   _IO_fwide (&sf->_sbf._f, 1);
 104   _IO_wstr_init_static (&sf->_sbf._f, (wchar_t *)string, 0, NULL);
 105   return &sf->_sbf._f;
 106 }
 107
 108 #endif /* strfile.h.  */