glibc/libio/oldfmemopen.c
Zack Weinberg 9964a14579 Mechanically remove _IO_ name aliases for types and constants.
This patch mechanically removes all remaining uses, and the
definitions, of the following libio name aliases:

 name                         replaced with
 ----                         -------------
 _IO_FILE                     FILE
 _IO_fpos_t                   __fpos_t
 _IO_fpos64_t                 __fpos64_t
 _IO_size_t                   size_t
 _IO_ssize_t                  ssize_t or __ssize_t
 _IO_off_t                    off_t
 _IO_off64_t                  off64_t
 _IO_pid_t                    pid_t
 _IO_uid_t                    uid_t
 _IO_wint_t                   wint_t
 _IO_va_list                  va_list or __gnuc_va_list
 _IO_BUFSIZ                   BUFSIZ
 _IO_cookie_io_functions_t    cookie_io_functions_t
 __io_read_fn                 cookie_read_function_t
 __io_write_fn                cookie_write_function_t
 __io_seek_fn                 cookie_seek_function_t
 __io_close_fn                cookie_close_function_t

I used __fpos_t and __fpos64_t instead of fpos_t and fpos64_t because
the definitions of fpos_t and fpos64_t depend on the largefile mode.
I used __ssize_t and __gnuc_va_list in a handful of headers where
namespace cleanliness might be relevant even though they're
internal-use-only.  In all other cases, I used the public-namespace
name.

There are a tiny handful of places where I left a use of 'struct _IO_FILE'
alone, because it was being used together with 'struct _IO_FILE_plus'
or 'struct _IO_FILE_complete' in the same arithmetic expression.

Because this patch was almost entirely done with search and replace, I
may have introduced indentation botches.  I did proofread the diff,
but I may have missed something.

The ChangeLog below calls out all of the places where this was not a
pure search-and-replace change.

Installed stripped libraries and executables are unchanged by this patch,
except that some assertions in vfscanf.c change line numbers.

	* libio/libio.h (_IO_FILE): Delete; all uses changed to FILE.
	(_IO_fpos_t): Delete; all uses changed to __fpos_t.
	(_IO_fpos64_t): Delete; all uses changed to __fpos64_t.
	(_IO_size_t): Delete; all uses changed to size_t.
	(_IO_ssize_t): Delete; all uses changed to ssize_t or __ssize_t.
	(_IO_off_t): Delete; all uses changed to off_t.
	(_IO_off64_t): Delete; all uses changed to off64_t.
	(_IO_pid_t): Delete; all uses changed to pid_t.
	(_IO_uid_t): Delete; all uses changed to uid_t.
	(_IO_wint_t): Delete; all uses changed to wint_t.
	(_IO_va_list): Delete; all uses changed to va_list or __gnuc_va_list.
	(_IO_BUFSIZ): Delete; all uses changed to BUFSIZ.
	(_IO_cookie_io_functions_t): Delete; all uses changed to
	cookie_io_functions_t.
	(__io_read_fn): Delete; all uses changed to cookie_read_function_t.
	(__io_write_fn): Delete; all uses changed to cookie_write_function_t.
	(__io_seek_fn): Delete; all uses changed to cookie_seek_function_t.
	(__io_close_fn): Delete: all uses changed to cookie_close_function_t.

	* libio/iofopncook.c: Remove unnecessary forward declarations.
	* libio/iolibio.h: Correct outdated commentary.
	* malloc/malloc.c (__malloc_stats): Remove unnecessary casts.
	* stdio-common/fxprintf.c (__fxprintf_nocancel):
	Remove unnecessary casts.
	* stdio-common/getline.c: Use _IO_getdelim directly.
	Don't redefine ssize_t.
	* stdio-common/printf_fp.c, stdio_common/printf_fphex.c
	* stdio-common/printf_size.c: Don't redefine size_t or FILE.
	Remove outdated comments.
	* stdio-common/vfscanf.c: Don't redefine va_list.
2018-02-21 14:11:05 -05:00

275 lines
6.0 KiB
C

/* Fmemopen implementation.
Copyright (C) 2000-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Hanno Mueller, kontakt@hanno.de, 2000.
The GNU C Library 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.
The GNU C Library 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 the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
/*
* fmemopen() - "my" version of a string stream
* Hanno Mueller, kontakt@hanno.de
*
*
* I needed fmemopen() for an application that I currently work on,
* but couldn't find it in libio. The following snippet of code is an
* attempt to implement what glibc's documentation describes.
*
*
*
* I already see some potential problems:
*
* - I never used the "original" fmemopen(). I am sure that "my"
* fmemopen() behaves differently than the original version.
*
* - The documentation doesn't say wether a string stream allows
* seeks. I checked the old fmemopen implementation in glibc's stdio
* directory, wasn't quite able to see what is going on in that
* source, but as far as I understand there was no seek there. For
* my application, I needed fseek() and ftell(), so it's here.
*
* - "append" mode and fseek(p, SEEK_END) have two different ideas
* about the "end" of the stream.
*
* As described in the documentation, when opening the file in
* "append" mode, the position pointer will be set to the first null
* character of the string buffer (yet the buffer may already
* contain more data). For fseek(), the last byte of the buffer is
* used as the end of the stream.
*
* - It is unclear to me what the documentation tries to say when it
* explains what happens when you use fmemopen with a NULL
* buffer.
*
* Quote: "fmemopen [then] allocates an array SIZE bytes long. This
* is really only useful if you are going to write things to the
* buffer and then read them back in again."
*
* What does that mean if the original fmemopen() did not allow
* seeking? How do you read what you just wrote without seeking back
* to the beginning of the stream?
*
* - I think there should be a second version of fmemopen() that does
* not add null characters for each write. (At least in my
* application, I am not actually using strings but binary data and
* so I don't need the stream to add null characters on its own.)
*/
#include "libioP.h"
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_22)
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
typedef struct fmemopen_cookie_struct fmemopen_cookie_t;
struct fmemopen_cookie_struct
{
char *buffer;
int mybuffer;
int binmode;
size_t size;
off64_t pos;
size_t maxpos;
};
static ssize_t
fmemopen_read (void *cookie, char *b, size_t s)
{
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
if (c->pos + s > c->size)
{
if ((size_t) c->pos == c->size)
return 0;
s = c->size - c->pos;
}
memcpy (b, &(c->buffer[c->pos]), s);
c->pos += s;
if ((size_t) c->pos > c->maxpos)
c->maxpos = c->pos;
return s;
}
static ssize_t
fmemopen_write (void *cookie, const char *b, size_t s)
{
fmemopen_cookie_t *c;
int addnullc;
c = (fmemopen_cookie_t *) cookie;
addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0');
if (c->pos + s + addnullc > c->size)
{
if ((size_t) (c->pos + addnullc) >= c->size)
{
__set_errno (ENOSPC);
return 0;
}
s = c->size - c->pos - addnullc;
}
memcpy (&(c->buffer[c->pos]), b, s);
c->pos += s;
if ((size_t) c->pos > c->maxpos)
{
c->maxpos = c->pos;
if (addnullc)
c->buffer[c->maxpos] = '\0';
}
return s;
}
static int
fmemopen_seek (void *cookie, off64_t *p, int w)
{
off64_t np;
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
switch (w)
{
case SEEK_SET:
np = *p;
break;
case SEEK_CUR:
np = c->pos + *p;
break;
case SEEK_END:
np = (c->binmode ? c->size : c->maxpos) - *p;
break;
default:
return -1;
}
if (np < 0 || (size_t) np > c->size)
return -1;
*p = c->pos = np;
return 0;
}
static int
fmemopen_close (void *cookie)
{
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
if (c->mybuffer)
free (c->buffer);
free (c);
return 0;
}
FILE *
__old_fmemopen (void *buf, size_t len, const char *mode)
{
cookie_io_functions_t iof;
fmemopen_cookie_t *c;
FILE *result;
if (__glibc_unlikely (len == 0))
{
einval:
__set_errno (EINVAL);
return NULL;
}
c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t));
if (c == NULL)
return NULL;
c->mybuffer = (buf == NULL);
if (c->mybuffer)
{
c->buffer = (char *) malloc (len);
if (c->buffer == NULL)
{
free (c);
return NULL;
}
c->buffer[0] = '\0';
c->maxpos = 0;
}
else
{
if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf))
{
free (c);
goto einval;
}
c->buffer = buf;
if (mode[0] == 'w')
c->buffer[0] = '\0';
c->maxpos = strnlen (c->buffer, len);
}
c->size = len;
if (mode[0] == 'a')
c->pos = c->maxpos;
else
c->pos = 0;
c->binmode = mode[0] != '\0' && mode[1] == 'b';
iof.read = fmemopen_read;
iof.write = fmemopen_write;
iof.seek = fmemopen_seek;
iof.close = fmemopen_close;
result = _IO_fopencookie (c, mode, iof);
if (__glibc_unlikely (result == NULL))
{
if (c->mybuffer)
free (c->buffer);
free (c);
}
return result;
}
compat_symbol (libc, __old_fmemopen, fmemopen, GLIBC_2_2);
#endif