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/* mpfr_inp_str -- input a number in base BASE from stdio stream STREAM
and store the result in ROP
Copyright 1999, 2001-2002, 2004, 2006-2023 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.
This file is part of the GNU MPFR Library.
The GNU MPFR 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 3 of the License, or (at your
option) any later version.
The GNU MPFR 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 MPFR Library; see the file COPYING.LESSER. If not, see
https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <ctype.h>
#include "mpfr-impl.h"
/* The original version of this function came from GMP's mpf/inp_str.c;
it has been adapted for MPFR. */
size_t
mpfr_inp_str (mpfr_ptr rop, FILE *stream, int base, mpfr_rnd_t rnd_mode)
{
unsigned char *str;
size_t alloc_size, str_size;
int c;
int retval;
size_t nread;
alloc_size = 100;
str = (unsigned char *) mpfr_allocate_func (alloc_size);
str_size = 0;
nread = 0;
/* Skip whitespace. EOF will be detected later. */
do
{
c = getc (stream);
nread++;
}
while (isspace (c));
/* number of characters read is nread */
for (;;)
{
MPFR_ASSERTD (str_size < (size_t) -1);
if (str_size >= alloc_size)
{
size_t old_alloc_size = alloc_size;
alloc_size = alloc_size / 2 * 3;
/* Handle overflow in unsigned integer arithmetic... */
if (MPFR_UNLIKELY (alloc_size <= old_alloc_size))
alloc_size = (size_t) -1;
MPFR_ASSERTD (str_size < alloc_size);
str = (unsigned char *)
mpfr_reallocate_func (str, old_alloc_size, alloc_size);
}
if (c == EOF || isspace (c))
break;
str[str_size++] = (unsigned char) c;
/* If c is '\0' (while not being a whitespace character), the word will
not have a valid format. But in the context of a string in memory,
'\0' is a terminating null character. So, to avoid ending with a
valid string format (like "1" with ignored characters after the
terminating null character), we need to make sure that the string
does not have a valid format; so let's start it with '*'. Note
that we should read the full word, so we cannot break. */
if (MPFR_UNLIKELY (c == '\0'))
str[0] = '*';
if (str_size == (size_t) -1)
break;
c = getc (stream);
}
/* The use of ungetc has been deprecated since C99 when it occurs at the
beginning of a binary stream, and this may happen on /dev/null. Here,
this is possible only for c == EOF. The condition "if (c != EOF)" below
is just there to handle this case. */
if (c != EOF)
ungetc (c, stream);
if (MPFR_UNLIKELY (str_size == (size_t) -1 || str_size == 0 ||
(c == EOF && ! feof (stream))))
{
/* size_t overflow or I/O error */
retval = -1;
}
else
{
/* number of characters read is nread + str_size - 1 */
/* We exited the "for" loop by the first break instruction,
then necessarily str_size >= alloc_size was checked, so
now str_size < alloc_size. */
MPFR_ASSERTD (str_size < alloc_size);
str[str_size] = '\0';
retval = mpfr_set_str (rop, (char *) str, base, rnd_mode);
}
mpfr_free_func (str, alloc_size);
if (retval == -1)
return 0; /* error */
MPFR_ASSERTD (nread >= 1);
str_size += nread - 1;
if (MPFR_UNLIKELY (str_size < nread - 1)) /* size_t overflow */
return 0; /* however, rop has been set successfully */
else
return str_size;
}
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