/*
 * Misc. functions for systems that don't have them
 *
 * Copyright 1996 Alexandre Julliard
 */

#include "config.h"
#include <sys/types.h>
#include <sys/time.h>

#ifndef HAVE_USLEEP
#ifdef __EMX__
unsigned int usleep (unsigned int useconds) { DosSleep(useconds); }
#else
unsigned int usleep (unsigned int useconds)
{
    struct timeval delay;

    delay.tv_sec = 0;
    delay.tv_usec = useconds;

    select( 0, 0, 0, 0, &delay );
    return 0;
}
#endif
#endif /* HAVE_USLEEP */

#ifndef HAVE_MEMMOVE
void *memmove( void *dest, const void *src, unsigned int len )
{
    register char *dst = dest;

    /* Use memcpy if not overlapping */
    if ((dst + len <= (char *)src) || ((char *)src + len <= dst))
    {
        memcpy( dst, src, len );
    }
    /* Otherwise do it the hard way (FIXME: could do better than this) */
    else if (dst < src)
    {
        while (len--) *dst++ = *((char *)src)++;
    }
    else
    {
        dst += len - 1;
        src = (char *)src + len - 1;
        while (len--) *dst-- = *((char *)src)--;
    }
    return dest;
}
#endif  /* HAVE_MEMMOVE */

#ifndef HAVE_STRERROR
const char *strerror( int err )
{
    /* Let's hope we have sys_errlist then */
    return sys_errlist[err];
}
#endif  /* HAVE_STRERROR */

#if !defined(HAVE_CLONE) && defined(__linux__)
#include <assert.h>
#include <errno.h>
#include <syscall.h>
int clone( int (*fn)(void *), void *stack, int flags, void *arg )
{
#ifdef __i386__
    int ret;
    void **stack_ptr = (void **)stack;
    *--stack_ptr = arg;  /* Push argument on stack */
    *--stack_ptr = fn;   /* Push function pointer (popped into ebx) */
    __asm__ __volatile__( "pushl %%ebx\n\t"
                          "movl %2,%%ebx\n\t"
                          "int $0x80\n\t"
                          "popl %%ebx\n\t"   /* Contains fn in the child */
                          "testl %%eax,%%eax\n\t"
                          "jnz 0f\n\t"
                          "call *%%ebx\n\t"       /* Should never return */
                          "xorl %%eax,%%eax\n\t"  /* Just in case it does*/
                          "0:"
                          : "=a" (ret)
                          : "0" (SYS_clone), "g" (flags), "c" (stack_ptr) );
    assert( ret );  /* If ret is 0, we returned from the child function */
    if (ret > 0) return ret;
    errno = -ret;
    return -1;
#else
    errno = EINVAL;
    return -1;
#endif  /* __i386__ */
}
#endif  /* !HAVE_CLONE && __linux__ */