From 0092e6fd45c4c6b6c4fc446d22c8b63eb168465c Mon Sep 17 00:00:00 2001
From: vsc <vsc@b08c6af1-5177-4d33-ba66-4b1c6b8b522a>
Date: Thu, 4 Mar 2004 18:33:34 +0000
Subject: [PATCH] support yap_flag(system_options,...

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1016 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
---
 C/corout.c        | 24 +++++++++++++++++++++++-
 C/stdpreds.c      |  2 --
 H/Yapproto.h      |  4 +---
 docs/yap.tex      |  8 ++++++++
 pl/directives.yap | 28 ++++++++++++++++++++++++++++
 5 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/C/corout.c b/C/corout.c
index 57627c600..3a04863e9 100644
--- a/C/corout.c
+++ b/C/corout.c
@@ -1220,8 +1220,28 @@ Yap_WakeUp(CELL *pt0) {
 }
 #endif
 
+static Int
+p_yap_has_rational_trees(void)
+{
+#if RATIONAL_TREES
+  return TRUE;
+#else
+  return FALSE;
+#endif
+}
 
-void Yap_InitCoroutPreds(void)
+static Int
+p_yap_has_coroutining(void)
+{
+#if COROUTINING
+  return TRUE;
+#else
+  return FALSE;
+#endif
+}
+
+void
+Yap_InitCoroutPreds(void)
 {
 #ifdef COROUTINING
   Atom            at;
@@ -1237,6 +1257,8 @@ void Yap_InitCoroutPreds(void)
   WakeUpCode = pred;
   Yap_InitAttVarPreds();
 #endif /* COROUTINING */
+  Yap_InitCPred("$yap_has_rational_trees", 0, p_yap_has_rational_trees, SafePredFlag);
+  Yap_InitCPred("$yap_has_coroutining", 0, p_yap_has_coroutining, SafePredFlag);
   Yap_InitCPred("$read_svar_list", 2, p_read_svar_list, SafePredFlag);
   Yap_InitCPred("$set_svar_list", 2, p_set_svar_list, SafePredFlag);
   Yap_InitCPred("$freeze", 2, p_freeze, 0);
diff --git a/C/stdpreds.c b/C/stdpreds.c
index ff77cd757..fe7ca875f 100644
--- a/C/stdpreds.c
+++ b/C/stdpreds.c
@@ -2796,9 +2796,7 @@ Yap_InitCPreds(void)
 #if defined(YAPOR) || defined(TABLING)
   Yap_init_optyap_preds();
 #endif /* YAPOR || TABLING */
-#ifdef THREADS
   Yap_InitThreadPreds();
-#endif /* ANALYST */
   {
     void            (*(*(p))) (void) = E_Modules;
     while (*p)
diff --git a/H/Yapproto.h b/H/Yapproto.h
index 3f191ca4e..b07f919c0 100644
--- a/H/Yapproto.h
+++ b/H/Yapproto.h
@@ -10,7 +10,7 @@
 * File:		Yap.proto						 *
 * mods:									 *
 * comments:	Function declarations for YAP				 *
-* version:      $Id: Yapproto.h,v 1.49 2004-03-02 16:44:58 vsc Exp $	 *
+* version:      $Id: Yapproto.h,v 1.50 2004-03-04 18:33:33 vsc Exp $	 *
 *************************************************************************/
 
 /* prototype file for Yap */
@@ -284,9 +284,7 @@ int	STD_PROTO(Yap_ProcessSIGINT,(void));
 double  STD_PROTO(Yap_random, (void));
 
 /* threads.c */
-#ifdef THREADS
 void   STD_PROTO(Yap_InitThreadPreds,(void));
-#endif /* ANALYST */
 
 /* tracer.c */
 #ifdef LOW_LEVEL_TRACER
diff --git a/docs/yap.tex b/docs/yap.tex
index 5821342ee..b6f3dcc52 100644
--- a/docs/yap.tex
+++ b/docs/yap.tex
@@ -6460,6 +6460,14 @@ Report the syntax error and generate an error.
 Just fail
 @end table
 
+@item system_options
+@findex system_options (yap_flag/2 option)
+@* This read only flag tells which options were used to compile
+Yap. Currently it informs whether the system supports
+@code{coroutining}, @code{depth_limit}, the @code{low_level_tracer},
+@code{or-parallelism}, @code{rational_trees}, @code{tabling},
+@code{threads}, or the @code{wam_profiler}.
+
 @item to_chars_mode
 @findex to_chars_modes (yap_flag/2 option)
 @* Define whether YAP should follow @code{quintus}-like
diff --git a/pl/directives.yap b/pl/directives.yap
index 0d2566295..0d3200284 100644
--- a/pl/directives.yap
+++ b/pl/directives.yap
@@ -404,6 +404,33 @@ yap_flag(single_var_warnings,X) :-
 yap_flag(single_var_warnings,X) :-
 	'$do_error'(domain_error(flag_value,single_var_warnings+X),yap_flag(single_var_warnings,X)).
 
+yap_flag(single_var_warnings,X) :-
+	var(X), !,
+	('$syntax_check_mode'(on,_), '$syntax_check_single_var'(on,_) ->
+	    X = on
+	;
+	    X = off
+	).
+yap_flag(system_options,X) :-
+	'$system_options'(X).
+
+'$system_options'(coroutining) :-
+	'$yap_has_coroutining'.
+'$system_options'(depth_limit) :-
+	\+ '$undefined'(get_depth_limit(_), prolog).
+'$system_options'(low_level_tracer) :-
+	\+ '$undefined'(start_low_level_trace, prolog).
+'$system_options'(or_parallelism) :-
+	\+ '$undefined'('$yapor_on', prolog).
+'$system_options'(rational_trees) :-
+	'$yap_has_rational_trees'.
+'$system_options'(tabling) :-
+	\+ '$undefined'('$do_table'(_,_), prolog).
+'$system_options'(threads) :-
+	\+ '$no_threads'.
+'$system_options'(wam_profiler) :-
+	\+ '$undefined'(reset_op_counters, prolog).
+	
 yap_flag(unknown,X) :-
 	var(X), !,
 	unknown(X,_).
@@ -565,6 +592,7 @@ yap_flag(host_type,X) :-
 	    V = strict_iso ;
 	    V = stack_dump_on_error ;
 	    V = syntax_errors ;
+	    V = system_options ;
 	    V = to_chars_mode ;
 	    V = toplevel_hook ;
 	    V = toplevel_print_options ;