1 /* mpz_set_str(mp_dest, string, base) -- Convert the \0-terminated
2 string STRING in base BASE to multiple precision integer in
3 MP_DEST. Allow white space in the string. If BASE == 0 determine
4 the base in the C standard way, i.e. 0xhh...h means base 16,
5 0oo...o means base 8, otherwise assume base 10.
6
7 Copyright 1991, 1993, 1994, 1996-1998, 2000-2003, 2005, 2011-2013 Free Software
8 Foundation, Inc.
9
10 This file is part of the GNU MP Library.
11
12 The GNU MP Library is free software; you can redistribute it and/or modify
13 it under the terms of either:
14
15 * the GNU Lesser General Public License as published by the Free
16 Software Foundation; either version 3 of the License, or (at your
17 option) any later version.
18
19 or
20
21 * the GNU General Public License as published by the Free Software
22 Foundation; either version 2 of the License, or (at your option) any
23 later version.
24
25 or both in parallel, as here.
26
27 The GNU MP Library is distributed in the hope that it will be useful, but
28 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
29 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
30 for more details.
31
32 You should have received copies of the GNU General Public License and the
33 GNU Lesser General Public License along with the GNU MP Library. If not,
34 see https://www.gnu.org/licenses/. */
35
36 #include <string.h>
37 #include <ctype.h>
38 #include "gmp-impl.h"
39 #include "longlong.h"
40
41 #define digit_value_tab __gmp_digit_value_tab
42
43 int
mpz_set_str(mpz_ptr x,const char * str,int base)44 mpz_set_str (mpz_ptr x, const char *str, int base)
45 {
46 size_t str_size;
47 char *s, *begs;
48 size_t i;
49 mp_size_t xsize;
50 int c;
51 int negative;
52 const unsigned char *digit_value;
53 TMP_DECL;
54
55 digit_value = digit_value_tab;
56 if (base > 36)
57 {
58 /* For bases > 36, use the collating sequence
59 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz. */
60 digit_value += 208;
61 if (UNLIKELY (base > 62))
62 return -1; /* too large base */
63 }
64
65 /* Skip whitespace. */
66 do
67 c = (unsigned char) *str++;
68 while (isspace (c));
69
70 negative = 0;
71 if (c == '-')
72 {
73 negative = 1;
74 c = (unsigned char) *str++;
75 }
76
77 if (digit_value[c] >= (base == 0 ? 10 : base))
78 return -1; /* error if no valid digits */
79
80 /* If BASE is 0, try to find out the base by looking at the initial
81 characters. */
82 if (base == 0)
83 {
84 base = 10;
85 if (c == '0')
86 {
87 base = 8;
88 c = (unsigned char) *str++;
89 if (c == 'x' || c == 'X')
90 {
91 base = 16;
92 c = (unsigned char) *str++;
93 }
94 else if (c == 'b' || c == 'B')
95 {
96 base = 2;
97 c = (unsigned char) *str++;
98 }
99 }
100 }
101
102 /* Skip leading zeros and white space. */
103 while (c == '0' || isspace (c))
104 c = (unsigned char) *str++;
105 /* Make sure the string does not become empty, mpn_set_str would fail. */
106 if (c == 0)
107 {
108 SIZ (x) = 0;
109 return 0;
110 }
111
112 TMP_MARK;
113 str_size = strlen (str - 1);
114 s = begs = (char *) TMP_ALLOC (str_size + 1);
115
116 /* Remove spaces from the string and convert the result from ASCII to a
117 byte array. */
118 for (i = 0; i < str_size; i++)
119 {
120 if (!isspace (c))
121 {
122 int dig = digit_value[c];
123 if (UNLIKELY (dig >= base))
124 {
125 TMP_FREE;
126 return -1;
127 }
128 *s++ = dig;
129 }
130 c = (unsigned char) *str++;
131 }
132
133 str_size = s - begs;
134
135 LIMBS_PER_DIGIT_IN_BASE (xsize, str_size, base);
136 MPZ_NEWALLOC (x, xsize);
137
138 /* Convert the byte array in base BASE to our bignum format. */
139 xsize = mpn_set_str (PTR (x), (unsigned char *) begs, str_size, base);
140 SIZ (x) = negative ? -xsize : xsize;
141
142 TMP_FREE;
143 return 0;
144 }
145