Austin Schuh | dace2a6 | 2020-08-18 10:56:48 -0700 | [diff] [blame^] | 1 | /* mpz_inp_str(dest_integer, stream, base) -- Input a number in base |
| 2 | BASE from stdio stream STREAM and store the result in DEST_INTEGER. |
| 3 | |
| 4 | OF THE FUNCTIONS IN THIS FILE, ONLY mpz_inp_str IS FOR EXTERNAL USE, THE |
| 5 | REST ARE INTERNALS AND ARE ALMOST CERTAIN TO BE SUBJECT TO INCOMPATIBLE |
| 6 | CHANGES OR DISAPPEAR COMPLETELY IN FUTURE GNU MP RELEASES. |
| 7 | |
| 8 | Copyright 1991, 1993, 1994, 1996, 1998, 2000-2003, 2011-2013 Free Software |
| 9 | Foundation, Inc. |
| 10 | |
| 11 | This file is part of the GNU MP Library. |
| 12 | |
| 13 | The GNU MP Library is free software; you can redistribute it and/or modify |
| 14 | it under the terms of either: |
| 15 | |
| 16 | * the GNU Lesser General Public License as published by the Free |
| 17 | Software Foundation; either version 3 of the License, or (at your |
| 18 | option) any later version. |
| 19 | |
| 20 | or |
| 21 | |
| 22 | * the GNU General Public License as published by the Free Software |
| 23 | Foundation; either version 2 of the License, or (at your option) any |
| 24 | later version. |
| 25 | |
| 26 | or both in parallel, as here. |
| 27 | |
| 28 | The GNU MP Library is distributed in the hope that it will be useful, but |
| 29 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 30 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 31 | for more details. |
| 32 | |
| 33 | You should have received copies of the GNU General Public License and the |
| 34 | GNU Lesser General Public License along with the GNU MP Library. If not, |
| 35 | see https://www.gnu.org/licenses/. */ |
| 36 | |
| 37 | #include <stdio.h> |
| 38 | #include <ctype.h> |
| 39 | #include "gmp-impl.h" |
| 40 | #include "longlong.h" |
| 41 | |
| 42 | #define digit_value_tab __gmp_digit_value_tab |
| 43 | |
| 44 | size_t |
| 45 | mpz_inp_str (mpz_ptr x, FILE *stream, int base) |
| 46 | { |
| 47 | int c; |
| 48 | size_t nread; |
| 49 | |
| 50 | if (stream == 0) |
| 51 | stream = stdin; |
| 52 | |
| 53 | nread = 0; |
| 54 | |
| 55 | /* Skip whitespace. */ |
| 56 | do |
| 57 | { |
| 58 | c = getc (stream); |
| 59 | nread++; |
| 60 | } |
| 61 | while (isspace (c)); |
| 62 | |
| 63 | return mpz_inp_str_nowhite (x, stream, base, c, nread); |
| 64 | } |
| 65 | |
| 66 | /* shared by mpq_inp_str */ |
| 67 | size_t |
| 68 | mpz_inp_str_nowhite (mpz_ptr x, FILE *stream, int base, int c, size_t nread) |
| 69 | { |
| 70 | char *str; |
| 71 | size_t alloc_size, str_size; |
| 72 | int negative; |
| 73 | mp_size_t xsize; |
| 74 | const unsigned char *digit_value; |
| 75 | |
| 76 | ASSERT_ALWAYS (EOF == -1); /* FIXME: handle this by adding explicit */ |
| 77 | /* comparisons of c and EOF before each */ |
| 78 | /* read of digit_value[]. */ |
| 79 | |
| 80 | digit_value = digit_value_tab; |
| 81 | if (base > 36) |
| 82 | { |
| 83 | /* For bases > 36, use the collating sequence |
| 84 | 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz. */ |
| 85 | digit_value += 208; |
| 86 | if (UNLIKELY (base > 62)) |
| 87 | return 0; /* too large base */ |
| 88 | } |
| 89 | |
| 90 | negative = 0; |
| 91 | if (c == '-') |
| 92 | { |
| 93 | negative = 1; |
| 94 | c = getc (stream); |
| 95 | nread++; |
| 96 | } |
| 97 | |
| 98 | if (c == EOF || digit_value[c] >= (base == 0 ? 10 : base)) |
| 99 | return 0; /* error if no digits */ |
| 100 | |
| 101 | /* If BASE is 0, try to find out the base by looking at the initial |
| 102 | characters. */ |
| 103 | if (base == 0) |
| 104 | { |
| 105 | base = 10; |
| 106 | if (c == '0') |
| 107 | { |
| 108 | base = 8; |
| 109 | c = getc (stream); |
| 110 | nread++; |
| 111 | if (c == 'x' || c == 'X') |
| 112 | { |
| 113 | base = 16; |
| 114 | c = getc (stream); |
| 115 | nread++; |
| 116 | } |
| 117 | else if (c == 'b' || c == 'B') |
| 118 | { |
| 119 | base = 2; |
| 120 | c = getc (stream); |
| 121 | nread++; |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | /* Skip leading zeros. */ |
| 127 | while (c == '0') |
| 128 | { |
| 129 | c = getc (stream); |
| 130 | nread++; |
| 131 | } |
| 132 | |
| 133 | alloc_size = 100; |
| 134 | str = __GMP_ALLOCATE_FUNC_TYPE (alloc_size, char); |
| 135 | str_size = 0; |
| 136 | |
| 137 | while (c != EOF) |
| 138 | { |
| 139 | int dig; |
| 140 | dig = digit_value[c]; |
| 141 | if (dig >= base) |
| 142 | break; |
| 143 | if (str_size >= alloc_size) |
| 144 | { |
| 145 | size_t old_alloc_size = alloc_size; |
| 146 | alloc_size = alloc_size * 3 / 2; |
| 147 | str = __GMP_REALLOCATE_FUNC_TYPE (str, old_alloc_size, alloc_size, char); |
| 148 | } |
| 149 | str[str_size++] = dig; |
| 150 | c = getc (stream); |
| 151 | } |
| 152 | nread += str_size; |
| 153 | |
| 154 | ungetc (c, stream); |
| 155 | nread--; |
| 156 | |
| 157 | /* Make sure the string is not empty, mpn_set_str would fail. */ |
| 158 | if (str_size == 0) |
| 159 | { |
| 160 | SIZ (x) = 0; |
| 161 | } |
| 162 | else |
| 163 | { |
| 164 | LIMBS_PER_DIGIT_IN_BASE (xsize, str_size, base); |
| 165 | MPZ_NEWALLOC (x, xsize); |
| 166 | |
| 167 | /* Convert the byte array in base BASE to our bignum format. */ |
| 168 | xsize = mpn_set_str (PTR (x), (unsigned char *) str, str_size, base); |
| 169 | SIZ (x) = negative ? -xsize : xsize; |
| 170 | } |
| 171 | (*__gmp_free_func) (str, alloc_size); |
| 172 | return nread; |
| 173 | } |