1 /* mpfr_inp_str -- input a number in base BASE from stdio stream STREAM 2 and store the result in ROP 3 4 Copyright 1999, 2001-2002, 2004, 2006-2023 Free Software Foundation, Inc. 5 Contributed by the AriC and Caramba projects, INRIA. 6 7 This file is part of the GNU MPFR Library. 8 9 The GNU MPFR Library is free software; you can redistribute it and/or modify 10 it under the terms of the GNU Lesser General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or (at your 12 option) any later version. 13 14 The GNU MPFR Library is distributed in the hope that it will be useful, but 15 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 16 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 17 License for more details. 18 19 You should have received a copy of the GNU Lesser General Public License 20 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 21 https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 22 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ 23 24 #include <ctype.h> 25 26 #include "mpfr-impl.h" 27 28 /* The original version of this function came from GMP's mpf/inp_str.c; 29 it has been adapted for MPFR. */ 30 31 size_t 32 mpfr_inp_str (mpfr_ptr rop, FILE *stream, int base, mpfr_rnd_t rnd_mode) 33 { 34 unsigned char *str; 35 size_t alloc_size, str_size; 36 int c; 37 int retval; 38 size_t nread; 39 40 alloc_size = 100; 41 str = (unsigned char *) mpfr_allocate_func (alloc_size); 42 str_size = 0; 43 nread = 0; 44 45 /* Skip whitespace. EOF will be detected later. */ 46 do 47 { 48 c = getc (stream); 49 nread++; 50 } 51 while (isspace (c)); 52 53 /* number of characters read is nread */ 54 55 for (;;) 56 { 57 MPFR_ASSERTD (str_size < (size_t) -1); 58 if (str_size >= alloc_size) 59 { 60 size_t old_alloc_size = alloc_size; 61 alloc_size = alloc_size / 2 * 3; 62 /* Handle overflow in unsigned integer arithmetic... */ 63 if (MPFR_UNLIKELY (alloc_size <= old_alloc_size)) 64 alloc_size = (size_t) -1; 65 MPFR_ASSERTD (str_size < alloc_size); 66 str = (unsigned char *) 67 mpfr_reallocate_func (str, old_alloc_size, alloc_size); 68 } 69 if (c == EOF || isspace (c)) 70 break; 71 str[str_size++] = (unsigned char) c; 72 if (str_size == (size_t) -1) 73 break; 74 c = getc (stream); 75 } 76 /* FIXME: The use of ungetc has been deprecated since C99 when it 77 occurs at the beginning of a binary stream, and this may happen 78 on /dev/null. One could add a "if (c != EOF)" test, but let's 79 wait for some discussion in comp.std.c first... */ 80 ungetc (c, stream); 81 82 if (MPFR_UNLIKELY (str_size == (size_t) -1 || str_size == 0 || 83 (c == EOF && ! feof (stream)))) 84 { 85 /* size_t overflow or I/O error */ 86 retval = -1; 87 } 88 else 89 { 90 /* number of characters read is nread + str_size - 1 */ 91 92 /* We exited the "for" loop by the first break instruction, 93 then necessarily str_size >= alloc_size was checked, so 94 now str_size < alloc_size. */ 95 MPFR_ASSERTD (str_size < alloc_size); 96 97 str[str_size] = '\0'; 98 99 retval = mpfr_set_str (rop, (char *) str, base, rnd_mode); 100 } 101 102 mpfr_free_func (str, alloc_size); 103 104 if (retval == -1) 105 return 0; /* error */ 106 107 MPFR_ASSERTD (nread >= 1); 108 str_size += nread - 1; 109 if (MPFR_UNLIKELY (str_size < nread - 1)) /* size_t overflow */ 110 return 0; /* however, rop has been set successfully */ 111 else 112 return str_size; 113 } 114