/* See the end of this file for copyright and license terms. */

#include <gay/types.h>

#include <string.h>

int memcmp(const void *s1, const void *s2, size_t n)
{
	int delta = 0;

	while (n-- > 0) {
		/* POSIX explicitly wants a cast to unsigned char */
		delta = *(const unsigned char *)s1++ - *(const unsigned char *)s2++;
		if (delta != 0)
			break;
	}

	return delta;
}

void *memcpy(void *dest, const void *src, size_t n)
{
	u8 *tmp = (u8 *)dest;

	while (n-- > 0)
		*tmp++ = *(const u8 *)src++;

	return dest;
}

void *memset(void *ptr, int c, size_t n)
{
	char *tmp = (char *)ptr;

	while (n-- > 0)
		*tmp++ = (char)c;

	return ptr;
}

void *memmove(void *dest, const void *src, size_t n)
{
	char *tmp = (char *)dest;
	const char *s = (const char *)src;

	if (dest == src)
		return dest;

	if (dest < src) {
		while (n-- != 0)
			*tmp++ = *s++;
	} else {
		tmp += n;
		s += n;
		while (n-- != 0)
			*--tmp = *--s;
	}

	return dest;
}

int strcmp(const char *s1, const char *s2)
{
	while (*s1 == *s2) {
		if (*s1++ == '\0' || *s2++ == '\0')
			break;
	}

	/* POSIX explicitly wants a cast to unsigned char */
	return *((const unsigned char *)s1) - *((const unsigned char *)s2);
}

char *strcpy(char *dest, const char *src)
{
	char *tmp = dest;

	while ((*tmp++ = *src++) != '\0');
		/* nothing */

	return dest;
}

char *strncpy(char *dest, const char *src, size_t n)
{
	char *tmp = dest;

	while (n-- != 0) {
		if ((*tmp++ = *src++) == '\0')
			break;
	}

	return dest;
}

size_t strlen(const char *s)
{
	const char *tmp = s;

	while (*tmp++ != '\0');
		/* nothing */

	return (size_t)tmp - (size_t)s - 1;
}

size_t strnlen(const char *s, size_t maxlen)
{
	const char *tmp = s;

	while (*tmp++ != '\0' && maxlen-- > 0);
		/* nothing */

	return (size_t)tmp - (size_t)s - 1;
}

/*
 * This file is part of GayBSD.
 * Copyright (c) 2021 fef <owo@fef.moe>.
 *
 * GayBSD is nonviolent software: you may only use, redistribute, and/or
 * modify it under the terms of the Cooperative Nonviolent Public License
 * (CNPL) as found in the LICENSE file in the source code root directory
 * or at <https://git.pixie.town/thufie/npl-builder>; either version 7
 * of the license, or (at your option) any later version.
 *
 * GayBSD comes with ABSOLUTELY NO WARRANTY, to the extent
 * permitted by applicable law.  See the CNPL for details.
 */