$NetBSD: patch-ab,v 1.6 2015/12/29 23:34:45 dholland Exp $

Use sys/param.h to detect timing configuration.
XXX: don't use sys/param.h.
All the world's not a Sun.
Avoid illegal lvalue cast.
Support more systems when looking inside FILE.

--- include.h.orig	1995-01-27 08:38:48.000000000 +0100
+++ include.h	2007-10-13 14:34:37.000000000 +0200
@@ -21,6 +21,7 @@
 
 #include <stdio.h>
 #include <math.h>
+#include <sys/param.h>
 
 /*	CPUTIME : print CPU time for UNIX 4.2 BSD
 *	if your system has times() function   #define CPUTIME 60
@@ -28,7 +29,11 @@
 *		else         		      #define CPUTIME 0
 */
 
+#if (defined(BSD) && BSD >= 199306)
+#define CPUTIME 60
+#else
 #define SUN4 1
+#endif
 #define KANJI 1		/* 1: allow EUC Kanji for str functions */
 
 /* Tee print macro */
@@ -133,10 +138,21 @@ struct term {			/* atomic formula (liter
 #define str_value(Term)   ((Term)->tag.s_value)
 #define filep_value(Term) ((Term)->tag.f_value)
 #define head_of_list(Term) (((struct clause *)Term)->c_form)
-#define tail_of_list(Term) ((struct term *)((struct clause *)Term)->c_link)
+#define tail_of_list(Term) (*((struct term **)&(((struct clause *)Term)->c_link)))
 
+#if defined(__linux__)
+#define is_readable(FP) (!(FP->_flags & _IO_NO_READS))
+#define is_writable(FP) (!(FP->_flags & _IO_NO_WRITES))
+#elif defined(__DragonFly__)
+#define is_readable(FP) (((struct __FILE_public *)(FP))->_flags & __SRD)
+#define is_writable(FP) (((struct __FILE_public *)(FP))->_flags & __SWR)
+#elif (defined(BSD) && BSD >= 199306)
+#define is_readable(FP) (FP->_flags & __SRD)
+#define is_writable(FP) (FP->_flags & __SWR)
+#else
 #define is_readable(FP) (FP->_flag & _IOREAD)
 #define is_writable(FP) (FP->_flag & _IOWRT)
+#endif
 
 #define is_functor(Term) ((Term)->type.ident > CONST_LIST_TYPE)
 #define isconst_functor(Term)  ((Term)->t_arity <= 0)