cosmopolitan/libc/fmt/strtoul.c
Justine Tunney e557058ac8
Improve cosmo's conformance to libc-test
This change addresses various open source compatibility issues, so that
we pass 313/411 of the tests in https://github.com/jart/libc-test where
earlier today we were passing about 30/411 of them, due to header toil.
Please note that Glibc only passes 341/411 so 313 today is pretty good!

- Make the conformance of libc/isystem/ headers nearly perfect
- Import more of the remaining math library routines from Musl
- Fix inconsistencies with type signatures of calls like umask
- Write tests for getpriority/setpriority which work great now
- conform to `struct sockaddr *` on remaining socket functions
- Import a bunch of uninteresting stdlib functions e.g. rand48
- Introduce readdir_r, scandir, pthread_kill, sigsetjmp, etc..

Follow the instructions in our `tool/scripts/cosmocc` toolchain to run
these tests yourself. You use `make CC=cosmocc` on the test repository
2022-10-10 17:52:41 -07:00

60 lines
3.1 KiB
C

/*-*- 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 │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/errno.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/strtol.internal.h"
#include "libc/limits.h"
#include "libc/str/str.h"
#include "libc/str/tab.internal.h"
/**
* Decodes unsigned 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 decoded integer mod 2⁶⁴ negated if leading `-`
* @raise ERANGE on overflow
*/
unsigned long strtoul(const char *s, char **endptr, int base) {
char t = 0;
int d, c = *s;
unsigned long x = 0;
CONSUME_SPACES(s, c);
GET_SIGN(s, c, d);
GET_RADIX(s, c, base);
if ((c = kBase36[c & 255]) && --c < base) {
t |= 1;
do {
if (__builtin_mul_overflow(x, base, &x) ||
__builtin_add_overflow(x, c, &x)) {
if (endptr) *endptr = s + 1;
errno = ERANGE;
return ULONG_MAX;
}
} while ((c = kBase36[*++s & 255]) && --c < base);
}
if (t && endptr) *endptr = s;
return d > 0 ? x : -x;
}