xref: /aosp_15_r20/external/arm-trusted-firmware/lib/libc/strtoll.c (revision 54fd6939e177f8ff529b10183254802c76df6d08)
1*54fd6939SJiyong Park /*-
2*54fd6939SJiyong Park  * SPDX-License-Identifier: BSD-3-Clause
3*54fd6939SJiyong Park  *
4*54fd6939SJiyong Park  * Copyright (c) 1992, 1993
5*54fd6939SJiyong Park  *	The Regents of the University of California.  All rights reserved.
6*54fd6939SJiyong Park  *
7*54fd6939SJiyong Park  * Copyright (c) 2011 The FreeBSD Foundation
8*54fd6939SJiyong Park  * All rights reserved.
9*54fd6939SJiyong Park  * Portions of this software were developed by David Chisnall
10*54fd6939SJiyong Park  * under sponsorship from the FreeBSD Foundation.
11*54fd6939SJiyong Park  *
12*54fd6939SJiyong Park  * Redistribution and use in source and binary forms, with or without
13*54fd6939SJiyong Park  * modification, are permitted provided that the following conditions
14*54fd6939SJiyong Park  * are met:
15*54fd6939SJiyong Park  * 1. Redistributions of source code must retain the above copyright
16*54fd6939SJiyong Park  *    notice, this list of conditions and the following disclaimer.
17*54fd6939SJiyong Park  * 2. Redistributions in binary form must reproduce the above copyright
18*54fd6939SJiyong Park  *    notice, this list of conditions and the following disclaimer in the
19*54fd6939SJiyong Park  *    documentation and/or other materials provided with the distribution.
20*54fd6939SJiyong Park  * 3. Neither the name of the University nor the names of its contributors
21*54fd6939SJiyong Park  *    may be used to endorse or promote products derived from this software
22*54fd6939SJiyong Park  *    without specific prior written permission.
23*54fd6939SJiyong Park  *
24*54fd6939SJiyong Park  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25*54fd6939SJiyong Park  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26*54fd6939SJiyong Park  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27*54fd6939SJiyong Park  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28*54fd6939SJiyong Park  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29*54fd6939SJiyong Park  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30*54fd6939SJiyong Park  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31*54fd6939SJiyong Park  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32*54fd6939SJiyong Park  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33*54fd6939SJiyong Park  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34*54fd6939SJiyong Park  * SUCH DAMAGE.
35*54fd6939SJiyong Park  */
36*54fd6939SJiyong Park 
37*54fd6939SJiyong Park #include <errno.h>
38*54fd6939SJiyong Park #include <limits.h>
39*54fd6939SJiyong Park #include <stddef.h>
40*54fd6939SJiyong Park #include <stdlib.h>
41*54fd6939SJiyong Park 
42*54fd6939SJiyong Park /*
43*54fd6939SJiyong Park  * Convert a string to a long long integer.
44*54fd6939SJiyong Park  *
45*54fd6939SJiyong Park  * Assumes that the upper and lower case
46*54fd6939SJiyong Park  * alphabets and digits are each contiguous.
47*54fd6939SJiyong Park  */
strtoll(const char * nptr,char ** endptr,int base)48*54fd6939SJiyong Park long long strtoll(const char *nptr, char **endptr, int base)
49*54fd6939SJiyong Park {
50*54fd6939SJiyong Park 	const char *s;
51*54fd6939SJiyong Park 	unsigned long long acc;
52*54fd6939SJiyong Park 	char c;
53*54fd6939SJiyong Park 	unsigned long long cutoff;
54*54fd6939SJiyong Park 	int neg, any, cutlim;
55*54fd6939SJiyong Park 
56*54fd6939SJiyong Park 	/*
57*54fd6939SJiyong Park 	 * Skip white space and pick up leading +/- sign if any.
58*54fd6939SJiyong Park 	 * If base is 0, allow 0x for hex and 0 for octal, else
59*54fd6939SJiyong Park 	 * assume decimal; if base is already 16, allow 0x.
60*54fd6939SJiyong Park 	 */
61*54fd6939SJiyong Park 	s = nptr;
62*54fd6939SJiyong Park 	do {
63*54fd6939SJiyong Park 		c = *s++;
64*54fd6939SJiyong Park 	} while (isspace((unsigned char)c));
65*54fd6939SJiyong Park 	if (c == '-') {
66*54fd6939SJiyong Park 		neg = 1;
67*54fd6939SJiyong Park 		c = *s++;
68*54fd6939SJiyong Park 	} else {
69*54fd6939SJiyong Park 		neg = 0;
70*54fd6939SJiyong Park 		if (c == '+')
71*54fd6939SJiyong Park 			c = *s++;
72*54fd6939SJiyong Park 	}
73*54fd6939SJiyong Park 	if ((base == 0 || base == 16) &&
74*54fd6939SJiyong Park 	    c == '0' && (*s == 'x' || *s == 'X') &&
75*54fd6939SJiyong Park 	    ((s[1] >= '0' && s[1] <= '9') ||
76*54fd6939SJiyong Park 	    (s[1] >= 'A' && s[1] <= 'F') ||
77*54fd6939SJiyong Park 	    (s[1] >= 'a' && s[1] <= 'f'))) {
78*54fd6939SJiyong Park 		c = s[1];
79*54fd6939SJiyong Park 		s += 2;
80*54fd6939SJiyong Park 		base = 16;
81*54fd6939SJiyong Park 	}
82*54fd6939SJiyong Park 	if (base == 0)
83*54fd6939SJiyong Park 		base = c == '0' ? 8 : 10;
84*54fd6939SJiyong Park 	acc = any = 0;
85*54fd6939SJiyong Park 
86*54fd6939SJiyong Park 	/*
87*54fd6939SJiyong Park 	 * Compute the cutoff value between legal numbers and illegal
88*54fd6939SJiyong Park 	 * numbers.  That is the largest legal value, divided by the
89*54fd6939SJiyong Park 	 * base.  An input number that is greater than this value, if
90*54fd6939SJiyong Park 	 * followed by a legal input character, is too big.  One that
91*54fd6939SJiyong Park 	 * is equal to this value may be valid or not; the limit
92*54fd6939SJiyong Park 	 * between valid and invalid numbers is then based on the last
93*54fd6939SJiyong Park 	 * digit.  For instance, if the range for quads is
94*54fd6939SJiyong Park 	 * [-9223372036854775808..9223372036854775807] and the input base
95*54fd6939SJiyong Park 	 * is 10, cutoff will be set to 922337203685477580 and cutlim to
96*54fd6939SJiyong Park 	 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
97*54fd6939SJiyong Park 	 * accumulated a value > 922337203685477580, or equal but the
98*54fd6939SJiyong Park 	 * next digit is > 7 (or 8), the number is too big, and we will
99*54fd6939SJiyong Park 	 * return a range error.
100*54fd6939SJiyong Park 	 *
101*54fd6939SJiyong Park 	 * Set 'any' if any `digits' consumed; make it negative to indicate
102*54fd6939SJiyong Park 	 * overflow.
103*54fd6939SJiyong Park 	 */
104*54fd6939SJiyong Park 	cutoff = neg ? (unsigned long long)-(LLONG_MIN + LLONG_MAX) + LLONG_MAX
105*54fd6939SJiyong Park 	    : LLONG_MAX;
106*54fd6939SJiyong Park 	cutlim = cutoff % base;
107*54fd6939SJiyong Park 	cutoff /= base;
108*54fd6939SJiyong Park 	for ( ; ; c = *s++) {
109*54fd6939SJiyong Park 		if (c >= '0' && c <= '9')
110*54fd6939SJiyong Park 			c -= '0';
111*54fd6939SJiyong Park 		else if (c >= 'A' && c <= 'Z')
112*54fd6939SJiyong Park 			c -= 'A' - 10;
113*54fd6939SJiyong Park 		else if (c >= 'a' && c <= 'z')
114*54fd6939SJiyong Park 			c -= 'a' - 10;
115*54fd6939SJiyong Park 		else
116*54fd6939SJiyong Park 			break;
117*54fd6939SJiyong Park 		if (c >= base)
118*54fd6939SJiyong Park 			break;
119*54fd6939SJiyong Park 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
120*54fd6939SJiyong Park 			any = -1;
121*54fd6939SJiyong Park 		else {
122*54fd6939SJiyong Park 			any = 1;
123*54fd6939SJiyong Park 			acc *= base;
124*54fd6939SJiyong Park 			acc += c;
125*54fd6939SJiyong Park 		}
126*54fd6939SJiyong Park 	}
127*54fd6939SJiyong Park 	if (any < 0) {
128*54fd6939SJiyong Park 		acc = neg ? LLONG_MIN : LLONG_MAX;
129*54fd6939SJiyong Park 	} else if (neg)
130*54fd6939SJiyong Park 		acc = -acc;
131*54fd6939SJiyong Park 	if (endptr != NULL)
132*54fd6939SJiyong Park 		*endptr = (char *)(any ? s - 1 : nptr);
133*54fd6939SJiyong Park 	return (acc);
134*54fd6939SJiyong Park }
135