ADDED: cov_property/1

Allows querying coverage collection system properties (currently
only whether coverage data collection is active).

library/prolog_coverage.pl

@@ -41,7 +41,8 @@
             show_coverage/2,            % :Goal, +Options (deprecated)
             cov_save_data/2,            % +File, +Options
             cov_load_data/2,            % +File, +Options
-            cov_reset/0                 %
+            cov_reset/0,                %
+            cov_property/1              % ?Property
           ]).
 :- autoload(library(apply), [exclude/3, maplist/2, convlist/3]).
 :- autoload(library(ordsets),
@@ -940,6 +941,19 @@
     '$cov_reset'.
 
 
+%!  cov_property(?Property)
+%
+%   True when coverage analysis satisfies   Property.  Currently defined
+%   properties are:
+%
+%     - active(?Nesting)
+%       True when coverage data is   being  collected. Nesting expresses
+%       the nesting of coverage/1 calls and is normally 1 (one).
+
+cov_property(active(Level)) :-
+    '$cov_active'(Level).
+
+
 		 /*******************************
 		 *             MESSAGES		*
 		 *******************************/

src/pl-coverage.c

@@ -563,16 +563,28 @@ PRED_IMPL("$cov_stop", 1, cov_stop, 0)
 }
 
 
+static
+PRED_IMPL("$cov_active", 1, cov_active, 0)
+{ PRED_LD
+
+  if ( !LD->coverage.active )
+    return FALSE;
+
+  return PL_unify_integer(A1, LD->coverage.active);
+}
+
+
 		 /*******************************
 		 *      PUBLISH PREDICATES	*
 		 *******************************/
 
 BeginPredDefs(coverage)
-  PRED_DEF("$cov_data",	 3, cov_data,  PL_FA_NONDETERMINISTIC)
-  PRED_DEF("$cov_add",   3, cov_add,   0)
-  PRED_DEF("$cov_reset", 0, cov_reset, 0)
-  PRED_DEF("$cov_start", 1, cov_start, 0)
-  PRED_DEF("$cov_stop",	 1, cov_stop,  0)
+  PRED_DEF("$cov_data",	  3, cov_data,   PL_FA_NONDETERMINISTIC)
+  PRED_DEF("$cov_add",    3, cov_add,    0)
+  PRED_DEF("$cov_reset",  0, cov_reset,  0)
+  PRED_DEF("$cov_start",  1, cov_start,  0)
+  PRED_DEF("$cov_stop",	  1, cov_stop,   0)
+  PRED_DEF("$cov_active", 1, cov_active, 0)
 EndPredDefs
 
 #endif /*O_COVERAGE*/