replaced references 'trace_simp' and 'debug_simp' by configuration options stored in the context

--- a/NEWS	Fri Mar 26 20:30:03 2010 +0100
+++ b/NEWS	Fri Mar 26 23:46:22 2010 +0100
@@ -61,6 +61,15 @@
 * Use of cumulative prems via "!" in some proof methods has been
 discontinued (legacy feature).
 
+* References 'trace_simp' and 'debug_simp' have been replaced by
+configuration options stored in the context. Enabling tracing
+(the case of debugging is similar) in proofs works via
+
+  using [[trace_simp=true]]
+
+Tracing is then active for all invocations of the simplifier
+in subsequent goal refinement steps.
+
 
 *** Pure ***
 

--- a/src/Pure/Isar/attrib.ML	Fri Mar 26 20:30:03 2010 +0100
+++ b/src/Pure/Isar/attrib.ML	Fri Mar 26 23:46:22 2010 +0100
@@ -396,6 +396,8 @@
   register_config Unify.search_bound_value #>
   register_config Unify.trace_simp_value #>
   register_config Unify.trace_types_value #>
-  register_config MetaSimplifier.simp_depth_limit_value));
+  register_config MetaSimplifier.simp_depth_limit_value #>
+  register_config MetaSimplifier.debug_simp_value #>
+  register_config MetaSimplifier.trace_simp_value));
 
 end;

--- a/src/Pure/ProofGeneral/preferences.ML	Fri Mar 26 20:30:03 2010 +0100
+++ b/src/Pure/ProofGeneral/preferences.ML	Fri Mar 26 23:46:22 2010 +0100
@@ -146,10 +146,7 @@
     "Show leading question mark of variable name"];
 
 val tracing_preferences =
- [bool_pref trace_simp
-    "trace-simplifier"
-    "Trace simplification rules.",
-  nat_pref trace_simp_depth_limit
+ [nat_pref trace_simp_depth_limit
     "trace-simplifier-depth"
     "Trace simplifier depth limit.",
   bool_pref trace_rules

--- a/src/Pure/meta_simplifier.ML	Fri Mar 26 20:30:03 2010 +0100
+++ b/src/Pure/meta_simplifier.ML	Fri Mar 26 23:46:22 2010 +0100
@@ -11,8 +11,10 @@
 
 signature BASIC_META_SIMPLIFIER =
 sig
-  val debug_simp: bool Unsynchronized.ref
-  val trace_simp: bool Unsynchronized.ref
+  val debug_simp: bool Config.T
+  val debug_simp_value: Config.value Config.T
+  val trace_simp: bool Config.T
+  val trace_simp_value: Config.value Config.T
   val trace_simp_depth_limit: int Unsynchronized.ref
   type rrule
   val eq_rrule: rrule * rrule -> bool
@@ -271,8 +273,11 @@
 
 exception SIMPLIFIER of string * thm;
 
-val debug_simp = Unsynchronized.ref false;
-val trace_simp = Unsynchronized.ref false;
+val debug_simp_value = Config.declare false "debug_simp" (Config.Bool false);
+val debug_simp = Config.bool debug_simp_value;
+
+val trace_simp_value = Config.declare false "trace_simp" (Config.Bool false);
+val trace_simp = Config.bool trace_simp_value;
 
 local
 
@@ -285,33 +290,39 @@
     fun subst (((b, T), _), x') = (Free (b, T), Syntax.mark_boundT (x', T));
   in Term.subst_atomic (ListPair.map subst (bs, xs)) t end;
 
+fun print_term ss warn a t ctxt = prnt ss warn (a () ^ "\n" ^
+  Syntax.string_of_term ctxt
+    (if Config.get ctxt debug_simp then t else show_bounds ss t));
+
 in
 
-fun print_term ss warn a thy t = prnt ss warn (a ^ "\n" ^
-  Syntax.string_of_term_global thy (if ! debug_simp then t else show_bounds ss t));
+fun print_term_global ss warn a thy t =
+  print_term ss warn (K a) t (ProofContext.init thy);
 
-fun debug warn a ss = if ! debug_simp then prnt ss warn (a ()) else ();
-fun trace warn a ss = if ! trace_simp then prnt ss warn (a ()) else ();
+fun if_enabled (Simpset ({context, ...}, _)) flag f =
+  (case context of
+    SOME ctxt => if Config.get ctxt flag then f ctxt else ()
+  | NONE => ())
 
-fun debug_term warn a ss thy t = if ! debug_simp then print_term ss warn (a ()) thy t else ();
-fun trace_term warn a ss thy t = if ! trace_simp then print_term ss warn (a ()) thy t else ();
+fun debug warn a ss = if_enabled ss debug_simp (fn _ => prnt ss warn (a ()));
+fun trace warn a ss = if_enabled ss trace_simp (fn _ => prnt ss warn (a ()));
+
+fun debug_term warn a ss t = if_enabled ss debug_simp (print_term ss warn a t);
+fun trace_term warn a ss t = if_enabled ss trace_simp (print_term ss warn a t);
 
 fun trace_cterm warn a ss ct =
-  if ! trace_simp then print_term ss warn (a ()) (Thm.theory_of_cterm ct) (Thm.term_of ct)
-  else ();
+  if_enabled ss trace_simp (print_term ss warn a (Thm.term_of ct));
 
 fun trace_thm a ss th =
-  if ! trace_simp then print_term ss false (a ()) (Thm.theory_of_thm th) (Thm.full_prop_of th)
-  else ();
+  if_enabled ss trace_simp (print_term ss false a (Thm.full_prop_of th));
 
 fun trace_named_thm a ss (th, name) =
-  if ! trace_simp then
-    print_term ss false (if name = "" then a () else a () ^ " " ^ quote name ^ ":")
-      (Thm.theory_of_thm th) (Thm.full_prop_of th)
-  else ();
+  if_enabled ss trace_simp (print_term ss false
+    (fn () => if name = "" then a () else a () ^ " " ^ quote name ^ ":")
+    (Thm.full_prop_of th));
 
 fun warn_thm a ss th =
-  print_term ss true a (Thm.theory_of_thm th) (Thm.full_prop_of th);
+  print_term_global ss true a (Thm.theory_of_thm th) (Thm.full_prop_of th);
 
 fun cond_warn_thm a (ss as Simpset ({context, ...}, _)) th =
   if is_some context then () else warn_thm a ss th;
@@ -824,7 +835,7 @@
       val _ $ _ $ prop0 = Thm.prop_of thm;
     in
       trace_thm (fn () => "Proved wrong thm (Check subgoaler?)") ss thm';
-      trace_term false (fn () => "Should have proved:") ss thy prop0;
+      trace_term false (fn () => "Should have proved:") ss prop0;
       NONE
     end;
 
@@ -943,7 +954,7 @@
     fun proc_rews [] = NONE
       | proc_rews (Proc {name, proc, lhs, ...} :: ps) =
           if Pattern.matches thyt (Thm.term_of lhs, Thm.term_of t) then
-            (debug_term false (fn () => "Trying procedure " ^ quote name ^ " on:") ss thyt eta_t;
+            (debug_term false (fn () => "Trying procedure " ^ quote name ^ " on:") ss eta_t;
              case proc ss eta_t' of
                NONE => (debug false (fn () => "FAILED") ss; proc_rews ps)
              | SOME raw_thm =>
@@ -1216,7 +1227,7 @@
         | _ => I) (term_of ct) [];
     in
       if null bs then ()
-      else print_term ss true ("Simplifier: term contains loose bounds: " ^ commas_quote bs)
+      else print_term_global ss true ("Simplifier: term contains loose bounds: " ^ commas_quote bs)
         (Thm.theory_of_cterm ct) (Thm.term_of ct)
     end
   else ();