From b382c060e3b7c5997987c2724805facccb44ce5e Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Thu, 31 Jan 2019 12:46:35 +0000
Subject: [PATCH] booting

---
 C/yap-args.c |  3 +--
 pl/boot.yap  | 46 ++++++++++++++++++++++++----------------------
 2 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/C/yap-args.c b/C/yap-args.c
index fbf25935d..c640c4851 100755
--- a/C/yap-args.c
+++ b/C/yap-args.c
@@ -1208,7 +1208,7 @@ X_API void YAP_Init(YAP_init_args *yap_init) {
     }
     LOCAL_consult_level = -1;
   }
-  Yap_do_low_level_trace=1;
+
   YAP_RunGoalOnce(TermInitProlog);
   if (yap_init->install && Yap_OUTPUT_STARTUP) {
     Term t = MkAtomTerm(Yap_LookupAtom(Yap_OUTPUT_STARTUP));
@@ -1217,7 +1217,6 @@ X_API void YAP_Init(YAP_init_args *yap_init) {
 
     YAP_RunGoalOnce(g);
   }
-  Yap_do_low_level_trace=0;
 
   end_init(yap_init);
 }
diff --git a/pl/boot.yap b/pl/boot.yap
index 97c21a4da..49b5d1ae9 100644
--- a/pl/boot.yap
+++ b/pl/boot.yap
@@ -38,6 +38,7 @@
 system_module(Mod, SysExps) :-
     system_module(Mod, SysExps, []).
 
+system_module(_Mod, _SysExps, _Decls) :- !.
 system_module(_Mod, _SysExps, _Decls) :-
       % '$new_system_predicates'(SysExps),
        fail.
@@ -75,7 +76,28 @@ private(_).
         (not)/1,
         repeat/0,
         throw/1,
-        true/0]).
+			     true/0]).
+
+:- system_module( '$_init', [!/0,
+        ':-'/1,
+        '?-'/1,
+        []/0,
+        extensions_to_present_answer/1,
+        fail/0,
+        false/0,
+        goal_expansion/2,
+        goal_expansion/3,
+        otherwise/0,
+        term_expansion/2,
+        version/2],
+	[
+	'$do_log_upd_clause'/6,
+        '$do_log_upd_clause0'/6,
+        '$do_log_upd_clause_erase'/6,
+        '$do_static_clause'/5],
+        '$system_module'/1]).
+
+:- use_system_module( '$_boot', ['$cut_by'/1]).
 
 % be careful here not to generate an undefined exception..
 
@@ -143,26 +165,6 @@ print_boot_message(Type,Error,Desc) :-
 :-  '$new_multifile'('$full_clause_optimisation'(_H, _M, _B0, _BF), prolog).
 :-  '$new_multifile'('$exec_directive'(_,_,_,_,_), prolog).
 
-:- system_module( '$_init', [!/0,
-        ':-'/1,
-        '?-'/1,
-        []/0,
-        extensions_to_present_answer/1,
-        fail/0,
-        false/0,
-        goal_expansion/2,
-        goal_expansion/3,
-        otherwise/0,
-        term_expansion/2,
-        version/2],
-	[
-	'$do_log_upd_clause'/6,
-        '$do_log_upd_clause0'/6,
-        '$do_log_upd_clause_erase'/6,
-        '$do_static_clause'/5], [
-        '$system_module'/1]).
-
-:- use_system_module( '$_boot', ['$cut_by'/1]).
 
 
 %:- start_low_level_trace.
@@ -216,7 +218,7 @@ print_boot_message(Type,Error,Desc) :-
 	  '$execute_command'(EG,EM,VL,Pos,Con,C) ;
 	  % do term expansion
 	  '$expand_term'(C, Con, EC),
-	  ( var(EC) ->
+	  ( nonvar(EC) ->
 	    '$yap_strip_module'(EC, EM2, EG2)
 	  ;
 	    '$yap_strip_module'(C, EM2, EG2)