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107b8a922a
2006-08-14 Ulrich Drepper <drepper@redhat.com> [BZ #1996] * libio/memstream.c (open_memstream): Allocate initial buffer with calloc. * libio/wmemstream.c (open_wmemstream): Likewise. * libio/strops.c: Pretty printing. (_IO_str_overflow): Clear uninitialized part of the new buffer. (enlarge_userbuf): New function. (_IO_str_seekoff): Call it if seek position is larger than current buffer. * libio/wstrops.c: Likewise. * libio/vasprintf.c: Add comment as to why we do not have to use calloc instead of malloc to allocate initial buffer. * libio/Makefile (tests): Add bug-memstream1 and bug-wmemstream1. * libio/bug-memstream1.c: New file. * libio/bug-wmemstream1.c: New file.
93 lines
3.4 KiB
C
93 lines
3.4 KiB
C
/* Copyright (C) 1995,1997,1999-2002,2004,2006 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA.
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As a special exception, if you link the code in this file with
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files compiled with a GNU compiler to produce an executable,
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that does not cause the resulting executable to be covered by
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the GNU Lesser General Public License. This exception does not
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however invalidate any other reasons why the executable file
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might be covered by the GNU Lesser General Public License.
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This exception applies to code released by its copyright holders
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in files containing the exception. */
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#include <malloc.h>
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#include <string.h>
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#include "libioP.h"
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#include "stdio.h"
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#include <stdio_ext.h>
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#include "strfile.h"
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int
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_IO_vasprintf (result_ptr, format, args)
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char **result_ptr;
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const char *format;
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_IO_va_list args;
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{
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/* Initial size of the buffer to be used. Will be doubled each time an
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overflow occurs. */
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const _IO_size_t init_string_size = 100;
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char *string;
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_IO_strfile sf;
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int ret;
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_IO_size_t needed;
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_IO_size_t allocated;
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/* No need to clear the memory here (unlike for open_memstream) since
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we know we will never seek on the stream. */
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string = (char *) malloc (init_string_size);
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if (string == NULL)
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return -1;
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#ifdef _IO_MTSAFE_IO
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sf._sbf._f._lock = NULL;
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#endif
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_IO_no_init ((_IO_FILE *) &sf._sbf, _IO_USER_LOCK, -1, NULL, NULL);
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_IO_JUMPS ((struct _IO_FILE_plus *) &sf._sbf) = &_IO_str_jumps;
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_IO_str_init_static_internal (&sf, string, init_string_size, string);
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sf._sbf._f._flags &= ~_IO_USER_BUF;
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sf._s._allocate_buffer = (_IO_alloc_type) malloc;
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sf._s._free_buffer = (_IO_free_type) free;
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ret = INTUSE(_IO_vfprintf) (&sf._sbf._f, format, args);
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if (ret < 0)
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{
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free (sf._sbf._f._IO_buf_base);
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return ret;
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}
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/* Only use realloc if the size we need is of the same (binary)
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order of magnitude then the memory we allocated. */
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needed = sf._sbf._f._IO_write_ptr - sf._sbf._f._IO_write_base + 1;
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allocated = sf._sbf._f._IO_write_end - sf._sbf._f._IO_write_base;
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if ((allocated >> 1) <= needed)
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*result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);
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else
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{
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*result_ptr = (char *) malloc (needed);
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if (*result_ptr != NULL)
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{
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memcpy (*result_ptr, sf._sbf._f._IO_buf_base, needed - 1);
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free (sf._sbf._f._IO_buf_base);
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}
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else
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/* We have no choice, use the buffer we already have. */
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*result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);
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}
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if (*result_ptr == NULL)
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*result_ptr = sf._sbf._f._IO_buf_base;
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(*result_ptr)[needed - 1] = '\0';
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return ret;
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}
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ldbl_weak_alias (_IO_vasprintf, vasprintf)
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