glibc/libio/strfile.h
Zack Weinberg 349718d4d7 Add __vfscanf_internal and __vfwscanf_internal with flags arguments.
There are two flags currently defined: SCANF_LDBL_IS_DBL is the mode
used by __nldbl_ scanf variants, and SCANF_ISOC99_A is the mode used
by __isoc99_ scanf variants.  In this patch, the new functions honor
these flag bits if they're set, but they still also look at the
corresponding bits of environmental state, and callers all pass zero.

The new functions do *not* have the "errp" argument possessed by
_IO_vfscanf and _IO_vfwscanf.  All internal callers passed NULL for
that argument.  External callers could theoretically exist, so I
preserved wrappers, but they are flagged as compat symbols and they
don't preserve the three-way distinction among types of errors that
was formerly exposed.  These functions probably should have been in
the list of deprecated _IO_ symbols in 2.27 NEWS -- they're not just
aliases for vfscanf and vfwscanf.

(It was necessary to introduce ldbl_compat_symbol for _IO_vfscanf.
Please check that part of the patch very carefully, I am still not
confident I understand all of the details of ldbl-opt.)

This patch also introduces helper inlines in libio/strfile.h that
encapsulate the process of initializing an _IO_strfile object for
reading.  This allows us to call __vfscanf_internal directly from
sscanf, and __vfwscanf_internal directly from swscanf, without
duplicating the initialization code.  (Previously, they called their
v-counterparts, but that won't work if we want to control *both* C99
mode and ldbl-is-dbl mode using the flags argument to__vfscanf_internal.)
It's still a little awkward, especially for wide strfiles, but it's
much better than what we had.

Tested for powerpc and powerpc64le.
2018-12-05 18:15:42 -02:00

114 lines
3.8 KiB
C

/* Copyright (C) 1993-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>.
As a special exception, if you link the code in this file with
files compiled with a GNU compiler to produce an executable,
that does not cause the resulting executable to be covered by
the GNU Lesser General Public License. This exception does not
however invalidate any other reasons why the executable file
might be covered by the GNU Lesser General Public License.
This exception applies to code released by its copyright holders
in files containing the exception. */
#ifndef STRFILE_H_
#define STRFILE_H_
#include "libioP.h"
typedef void *(*_IO_alloc_type) (size_t);
typedef void (*_IO_free_type) (void*);
struct _IO_str_fields
{
/* These members are preserved for ABI compatibility. The glibc
implementation always calls malloc/free for user buffers if
_IO_USER_BUF or _IO_FLAGS2_USER_WBUF are not set. */
_IO_alloc_type _allocate_buffer_unused;
_IO_free_type _free_buffer_unused;
};
/* This is needed for the Irix6 N32 ABI, which has a 64 bit off_t type,
but a 32 bit pointer type. In this case, we get 4 bytes of padding
after the vtable pointer. Putting them in a structure together solves
this problem. */
struct _IO_streambuf
{
FILE _f;
const struct _IO_jump_t *vtable;
};
typedef struct _IO_strfile_
{
struct _IO_streambuf _sbf;
struct _IO_str_fields _s;
} _IO_strfile;
/* frozen: set when the program has requested that the array object not
be altered, reallocated, or freed. */
#define _IO_STR_FROZEN(FP) ((FP)->_f._flags & _IO_USER_BUF)
typedef struct
{
_IO_strfile f;
/* This is used for the characters which do not fit in the buffer
provided by the user. */
char overflow_buf[64];
} _IO_strnfile;
extern const struct _IO_jump_t _IO_strn_jumps attribute_hidden;
typedef struct
{
_IO_strfile f;
/* This is used for the characters which do not fit in the buffer
provided by the user. */
wchar_t overflow_buf[64];
} _IO_wstrnfile;
extern const struct _IO_jump_t _IO_wstrn_jumps attribute_hidden;
/* Initialize an _IO_strfile SF to read from narrow string STRING, and
return the corresponding FILE object. It is not necessary to fclose
the FILE when it is no longer needed. */
static inline FILE *
_IO_strfile_read (_IO_strfile *sf, const char *string)
{
sf->_sbf._f._lock = NULL;
_IO_no_init (&sf->_sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
_IO_JUMPS (&sf->_sbf) = &_IO_str_jumps;
_IO_str_init_static_internal (sf, (char*)string, 0, NULL);
return &sf->_sbf._f;
}
/* Initialize an _IO_strfile SF and _IO_wide_data WD to read from wide
string STRING, and return the corresponding FILE object. It is not
necessary to fclose the FILE when it is no longer needed. */
static inline FILE *
_IO_strfile_readw (_IO_strfile *sf, struct _IO_wide_data *wd,
const wchar_t *string)
{
sf->_sbf._f._lock = NULL;
_IO_no_init (&sf->_sbf._f, _IO_USER_LOCK, 0, wd, &_IO_wstr_jumps);
_IO_fwide (&sf->_sbf._f, 1);
_IO_wstr_init_static (&sf->_sbf._f, (wchar_t *)string, 0, NULL);
return &sf->_sbf._f;
}
#endif /* strfile.h. */