This is a maintenance fork
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

122 lines
4.0 KiB

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/conv/conv.h"
#include "libc/limits.h"
#include "libc/nexgen32e/bsr.h"
#include "libc/str/str.h"
/**
* Decodes 128-bit signed integer from ASCII string.
*
* @param s is a non-NULL NUL-terminated string
* @param endptr if non-NULL will always receive a pointer to the char
* following the last one this function processed, which is usually
* the NUL byte, or in the case of invalid strings, would point to
* the first invalid character
* @param base can be anywhere between [2,36] or 0 to auto-detect based
* on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or
* decimal (base 10) by default.
* @return the decoded saturated number
* @see strtoumax
*/
intmax_t strtoimax(const char *s, char **endptr, int base) {
uintmax_t x;
intmax_t res;
unsigned diglet, bits;
bool neg, islong, isunsigned;
x = 0;
bits = 0;
neg = false;
while (isspace(*s)) {
s++;
}
switch (*s) {
case '-':
neg = true;
/* 𝑠𝑙𝑖𝑑𝑒 */
case '+':
s++;
break;
default:
break;
}
if (!(2 <= base && base <= 36)) {
if (*s == '0') {
s++;
if (*s == 'x' || *s == 'X') {
s++;
base = 16;
} else if (*s == 'b' || *s == 'B') {
s++;
base = 2;
} else {
base = 8;
}
} else {
base = 10;
}
}
for (;;) {
diglet = kBase36[*s & 0xff];
if (!diglet || diglet > base) break;
diglet -= 1;
if (!diglet || !x || (bits = bsr(diglet) + bsrmax(x)) < 127) {
s++;
x *= base;
x += diglet;
} else if (neg) {
if (bits == 127) {
x *= base;
x += diglet;
if (x == INTMAX_MIN) s++;
}
x = INTMAX_MIN;
break;
} else {
x = INTMAX_MAX;
break;
}
}
if ((isunsigned = *s == 'u' || *s == 'U')) s++;
if ((islong = *s == 'l' || *s == 'L')) s++;
if (endptr) *endptr = s;
if (neg) {
res = -x;
} else {
res = x;
}
if (isunsigned) {
if (islong) {
res = (uint64_t)res;
} else {
res = (uint32_t)res;
}
}
return res;
}