/*
 *  SPL - The SPL Programming Language
 *  Copyright (C) 2004, 2005  Clifford Wolf <clifford@clifford.at>
 *
 *  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; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  compat.h: Some defines and inlines for non-gnu systems
 *
 */

#ifndef SPL_COMPAT_H
#define SPL_COMPAT_H

#include <stdlib.h>


#if defined __GNUC__ && (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
#  define UNUSED(x) x __attribute__((unused))
#elif defined(__LCLINT__)
#  define UNUSED(x) /*@unused@*/ x
#else
#  define UNUSED(x) x
#endif


#if defined __MACH__ && defined __APPLE__
#  define COMPAT_MEMRCHR
#  define COMPAT_STRNDUPA
#  define COMPAT_STRNDUP
#  define COMPAT_MEMMEM
#  define COMPAT_DPRINTF
#  define COMPAT_SENDFILE
#elif !(defined __GLIBC__ && defined __GLIBC_MINOR__) || defined _FORCE_COMPAT_FUNCS
#  define COMPAT_ALLOCA
#  define COMPAT_MEMRCHR
#  define COMPAT_STRSEP
#  define COMPAT_STRNDUPA
#  define COMPAT_STRNDUP
#  define COMPAT_MEMMEM
#  define COMPAT_ASPRINTF
#  define COMPAT_VASPRINTF
#  define COMPAT_DPRINTF
#  define COMPAT_SENDFILE
#endif


#ifdef COMPAT_ALLOCA
#  define my_alloca(_s) __builtin_alloca(_s)
#else
#  define my_alloca alloca
#endif

#ifdef COMPAT_MEMRCHR
    static inline void *my_memrchr(const void *s, int c, size_t n)
    {
    	const char *sx = s;
    	for (int counter = n; counter >= 0; counter--)
    		if (sx[counter] == c) return (void*)(sx+counter);
    	return 0;
    }
#else
#  define my_memrchr memrchr
#endif

#ifdef COMPAT_STRSEP
    static inline char *my_strsep(char **s, const char *ct)
    {
    	char *begin = *s, *end = *s;

    	if (!begin)
    		return 0;

    	while (*end && !strchr(ct, *end))
    		end++;

    	if (*end) {
    		*end = 0;
    		*s = end+1;
    	} else
    		*s = 0;

    	return begin;
    }
#else
#  define my_strsep	strsep
#endif


#ifdef COMPAT_STRNDUPA
#  define my_strndupa(s, n)						\
	({								\
		char *__new = (char *) __builtin_alloca ((n) + 1);	\
		strncpy(__new, (s), (n));				\
		__new[(n)] = '\0'; __new;				\
	})
#else
#  define my_strndupa strndupa
#endif

#ifdef COMPAT_STRNDUP
#  define my_strndup(s, n)						\
	({								\
		char *__new = (char *) malloc ((n) + 1);		\
		strncpy(__new, (s), (n));				\
		__new[(n)] = '\0'; __new;				\
	})
#else
#  define my_strndup strndup
#endif

#ifdef COMPAT_MEMMEM
    static inline void *my_memmem(const void *haystack, size_t haystacklen,
    		const void *needle, size_t needlelen)
    {
    	if (needlelen <= haystacklen) {
    		for (unsigned int i=0; i <= haystacklen-needlelen; i++)
    			if (!memcmp(haystack+i, needle, needlelen))
    				return (void*)(haystack+i);
    	}
    	return 0;
    }
#else
#  define my_memmem memmem
#endif

#if defined USEWIN32API

#ifndef COMPAT_H_NO_WIN_INCL
#    include <stdarg.h>
#    include <windef.h>
#    include <winbase.h>
#endif

#  define MY_O_BINARY O_BINARY
#  define my_sleep(sec) Sleep((sec)*1000)

#else

#  define MY_O_BINARY 0
#  define my_sleep sleep

#endif

#ifdef COMPAT_ASPRINTF
#  define my_asprintf(__result, fmt, ...)				\
	({								\
		int __size = 64, __rc;					\
		*(__result) = malloc(__size + 1);			\
		while (1) {						\
			__rc = snprintf(*(__result), __size + 1,	\
					(fmt), ## __VA_ARGS__);		\
			if (__rc >= 0 && __rc < __size) break;		\
			__size *= 2;					\
			*(__result) = realloc(*(__result), __size + 1);	\
		} 							\
		__rc;							\
	})
#else
#  define my_asprintf asprintf
#endif

#ifdef COMPAT_VASPRINTF
#  define my_vasprintf(__result, fmt, ap)				\
	({								\
		int __size = 64, __rc;					\
		*(__result) = malloc(__size + 1);			\
		while (1) {						\
		    va_list apc;    \
            va_copy(apc, ap);   \
			__rc = vsnprintf(*(__result), __size + 1,	\
					 (fmt), (apc));			\
			va_end(apc);    \
			if (__rc >= 0 && __rc < __size) break;		\
			__size *= 2;					\
			*(__result) = realloc(*(__result), __size + 1);	\
		} 							\
		__rc;							\
	})
#else
#  define my_vasprintf vasprintf
#endif


#ifdef COMPAT_DPRINTF
#  include <unistd.h>

    static inline int my_dprintf(int fd, const char *fmt, ...)		\
    {									\
    	char *data;							\
    	va_list ap;							\
    	va_start(ap, fmt);						\
    	const int rc = my_vasprintf(&data, fmt, ap);			\
    	va_end(ap);							\
    	for (int written = 0, rc2; written < rc; written += rc2) {	\
    		rc2 = write(fd, data+written, rc-written);		\
    		if (rc2 <= 0) break;					\
    	}								\
    	free(data);							\
    	return rc;							\
    }
#else
#  define my_dprintf dprintf
#endif


#ifdef COMPAT_SENDFILE
#  include <unistd.h>

    static inline ssize_t my_sendfile(int out_fd, int in_fd, off_t UNUSED(*offset), size_t count)
    {
    	char buffer[count];
    	const int read_rc = read(in_fd, buffer, count);

    	if (read_rc <= 0)
    		return read_rc;

    	int write_rc = 0;

    	while (write_rc < read_rc) {
    		int rc = write(out_fd, buffer+write_rc, read_rc-write_rc);
    		if (rc <= 0) return rc ? rc : write_rc;
    		write_rc += rc;
    	}

    	return write_rc;
    }
#else
#  define my_sendfile sendfile
#endif

#endif