1/*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35/*
36 * Convert a string to a long long integer.
37 *
38 * Assumes that the upper and lower case
39 * alphabets and digits are each contiguous.
40 */
41long long
42qt_strtoll(const char * nptr, char **endptr, int base)
43{
44 const char *s;
45 unsigned long long acc;
46 char c;
47 unsigned long long cutoff;
48 int neg, any, cutlim;
49
50 /*
51 * Skip white space and pick up leading +/- sign if any.
52 * If base is 0, allow 0x for hex and 0 for octal, else
53 * assume decimal; if base is already 16, allow 0x.
54 */
55 s = nptr;
56 do {
57 c = *s++;
58 } while (ascii_isspace(c));
59 if (c == '-') {
60 neg = 1;
61 c = *s++;
62 } else {
63 neg = 0;
64 if (c == '+')
65 c = *s++;
66 }
67 if ((base == 0 || base == 16) &&
68 c == '0' && (*s == 'x' || *s == 'X') &&
69 ((s[1] >= '0' && s[1] <= '9') ||
70 (s[1] >= 'A' && s[1] <= 'F') ||
71 (s[1] >= 'a' && s[1] <= 'f'))) {
72 c = s[1];
73 s += 2;
74 base = 16;
75 }
76 if (base == 0)
77 base = c == '0' ? 8 : 10;
78 acc = any = 0;
79 if (base < 2 || base > 36)
80 goto noconv;
81
82 /*
83 * Compute the cutoff value between legal numbers and illegal
84 * numbers. That is the largest legal value, divided by the
85 * base. An input number that is greater than this value, if
86 * followed by a legal input character, is too big. One that
87 * is equal to this value may be valid or not; the limit
88 * between valid and invalid numbers is then based on the last
89 * digit. For instance, if the range for quads is
90 * [-9223372036854775808..9223372036854775807] and the input base
91 * is 10, cutoff will be set to 922337203685477580 and cutlim to
92 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
93 * accumulated a value > 922337203685477580, or equal but the
94 * next digit is > 7 (or 8), the number is too big, and we will
95 * return a range error.
96 *
97 * Set 'any' if any `digits' consumed; make it negative to indicate
98 * overflow.
99 */
100 cutoff = neg ? (unsigned long long)-(LLONG_MIN + LLONG_MAX) + LLONG_MAX
101 : LLONG_MAX;
102 cutlim = cutoff % base;
103 cutoff /= base;
104 for ( ; ; c = *s++) {
105 if (c >= '0' && c <= '9')
106 c -= '0';
107 else if (c >= 'A' && c <= 'Z')
108 c -= 'A' - 10;
109 else if (c >= 'a' && c <= 'z')
110 c -= 'a' - 10;
111 else
112 break;
113 if (c >= base)
114 break;
115 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
116 any = -1;
117 else {
118 any = 1;
119 acc *= base;
120 acc += c;
121 }
122 }
123 if (any < 0) {
124 acc = neg ? LLONG_MIN : LLONG_MAX;
125 errno = ERANGE;
126 } else if (!any) {
127noconv:
128 errno = EINVAL;
129 } else if (neg)
130 acc = -acc;
131 if (endptr != NULL)
132 *endptr = const_cast<char *>(any ? s - 1 : nptr);
133 return (acc);
134}
135

source code of qtbase/src/3rdparty/freebsd/strtoll.c