1 /* This file is part of Libspectre.
2 *
3 * Copyright (C) 2007, 2012 Albert Astals Cid <aacid@kde.org>
4 * Copyright (C) 2007 Carlos Garcia Campos <carlosgc@gnome.org>
5 *
6 * Libspectre is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2, or (at your option)
9 * any later version.
10 *
11 * Libspectre is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20
21 /* This function comes from spectre-utils from libspectre */
22
23 #include "gstrtod.h"
24
25 #include <clocale>
26 #include <cerrno>
27 #include <cstdlib>
28 #include <cstring>
29
30 #define ascii_isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
31 #define ascii_isdigit(c) (c >= '0' && c <= '9')
32
gatof(const char * nptr)33 double gatof(const char *nptr)
34 {
35 return gstrtod(nptr, nullptr);
36 }
37
gstrtod(const char * nptr,char ** endptr)38 double gstrtod(const char *nptr, char **endptr)
39 {
40 char *fail_pos;
41 double val;
42 struct lconv *locale_data;
43 const char *decimal_point;
44 int decimal_point_len;
45 const char *p, *decimal_point_pos;
46 const char *end = nullptr; /* Silence gcc */
47 int strtod_errno;
48
49 fail_pos = nullptr;
50
51 locale_data = localeconv();
52 decimal_point = locale_data->decimal_point;
53 decimal_point_len = strlen(decimal_point);
54
55 decimal_point_pos = nullptr;
56 end = nullptr;
57
58 if (decimal_point[0] != '.' || decimal_point[1] != 0) {
59 p = nptr;
60 /* Skip leading space */
61 while (ascii_isspace(*p))
62 p++;
63
64 /* Skip leading optional sign */
65 if (*p == '+' || *p == '-')
66 p++;
67
68 if (ascii_isdigit(*p) || *p == '.') {
69 while (ascii_isdigit(*p))
70 p++;
71
72 if (*p == '.')
73 decimal_point_pos = p++;
74
75 while (ascii_isdigit(*p))
76 p++;
77
78 if (*p == 'e' || *p == 'E')
79 p++;
80 if (*p == '+' || *p == '-')
81 p++;
82 while (ascii_isdigit(*p))
83 p++;
84
85 end = p;
86 }
87 /* For the other cases, we need not convert the decimal point */
88 }
89
90 if (decimal_point_pos) {
91 char *copy, *c;
92
93 /* We need to convert the '.' to the locale specific decimal point */
94 copy = (char *)malloc(end - nptr + 1 + decimal_point_len);
95
96 c = copy;
97 memcpy(c, nptr, decimal_point_pos - nptr);
98 c += decimal_point_pos - nptr;
99 memcpy(c, decimal_point, decimal_point_len);
100 c += decimal_point_len;
101 memcpy(c, decimal_point_pos + 1, end - (decimal_point_pos + 1));
102 c += end - (decimal_point_pos + 1);
103 *c = 0;
104
105 errno = 0;
106 val = strtod(copy, &fail_pos);
107 strtod_errno = errno;
108
109 if (fail_pos) {
110 if (fail_pos - copy > decimal_point_pos - nptr)
111 fail_pos = (char *)nptr + (fail_pos - copy) - (decimal_point_len - 1);
112 else
113 fail_pos = (char *)nptr + (fail_pos - copy);
114 }
115
116 free(copy);
117 } else if (end) {
118 char *copy;
119
120 copy = (char *)malloc(end - (char *)nptr + 1);
121 memcpy(copy, nptr, end - nptr);
122 *(copy + (end - (char *)nptr)) = 0;
123
124 errno = 0;
125 val = strtod(copy, &fail_pos);
126 strtod_errno = errno;
127
128 if (fail_pos) {
129 fail_pos = (char *)nptr + (fail_pos - copy);
130 }
131
132 free(copy);
133 } else {
134 errno = 0;
135 val = strtod(nptr, &fail_pos);
136 strtod_errno = errno;
137 }
138
139 if (endptr)
140 *endptr = fail_pos;
141
142 errno = strtod_errno;
143
144 return val;
145 }
146