Ignore never by default

src/spins/Compile.java

@@ -148,9 +148,6 @@ public class Compile {
 		final OptionParser parser = 
 			new OptionParser("java spins.Compiler", shortd, longd, true);
 
-		final BooleanOption nonever = new BooleanOption('n', "No never");
-		parser.addOption(nonever);
-
 		final StringOption define = new StringOption('D',
 			"sets preprocessor macro define value", true);
 		parser.addOption(define);
@@ -195,7 +192,11 @@ public class Compile {
 		final BooleanOption total = new BooleanOption('T',
 			"make next-state a total function\n");
 		parser.addOption(total);
-        
+
+		final BooleanOption useNever = new BooleanOption('N',
+			"Force use of never claim (slow; it is preferable to supply the LTL formula to LTSmin).\n");
+		parser.addOption(useNever);
+
         final BooleanOption preprocessor = new BooleanOption('I',
 			"prints output of preprocessor\n");
 		parser.addOption(preprocessor);
@@ -272,13 +273,18 @@ public class Compile {
 		}
 
         Options opts = new Options(verbose.isSet(), no_guards.isSet(),
-                must_write.isSet(), !no_cnf.isSet(),
-                nonever.isSet(), java.isSet(), no_atomic.isSet(), total.isSet());
+                					  must_write.isSet(), !no_cnf.isSet(),
+                					  java.isSet(), no_atomic.isSet(), total.isSet());
 
 		final Specification spec = 
 			Compile.compile(file, !optimalizations.isSet("3"), opts);
 
-        if (nonever.isSet()) spec.setNever(null);
+		if (!useNever.isSet() && spec.getNever() != null) {
+    			LTSminTreeWalker.NEVER = false;
+    			System.out.println("\nWARNING: Ignoring NEVER claim. Supply LTL formula to LTSmin or override with -N.\n\n");
+        		spec.setNever(null);
+        }
+
         if (spec == null) {
             System.exit(-4);
         }
@@ -347,9 +353,11 @@ public class Compile {
 										Expression progress) {
 		final File dotFile = new File(outputDir, name + ".spins.dot");
 
+		
 		LTSminTreeWalker walker = new LTSminTreeWalker(spec, ltsmin_ltl);
 		LTSminModel model = walker.createLTSminModel(name, opts,
 		                                             exports, progress);
+
 		String out = "digraph {\n";
 		for (LTSminTransition t : model.getTransitions()) {
 			String s[] = t.getName().split(" X ");

src/spins/promela/compiler/ltsmin/LTSminDMWalker.java

@@ -101,7 +101,7 @@ public class LTSminDMWalker {
 	}
 	
 	private static RWMatrix DUMMY_MATRIX = new RWMatrix(null, null, null);
-	private static Options DUMMY_OPTIONS = new Options(false, false, false, false, false, false, false, false);
+	private static Options DUMMY_OPTIONS = new Options(false, false, false, false, false, false, false);
 	private static Params sParams = new Params(null, null, DUMMY_MATRIX,
 	                                           0, DUMMY_OPTIONS);
 	public static void walkOneGuard(LTSminModel model, DepMatrix dm,

src/spins/promela/compiler/ltsmin/LTSminTreeWalker.java

@@ -40,13 +40,11 @@ import java.io.IOException;
 import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
-import java.util.Set;
 
 import spins.promela.compiler.Preprocessor;
 import spins.promela.compiler.Preprocessor.DefineMapping;
@@ -158,7 +156,7 @@ public class LTSminTreeWalker {
 	}
 
 	private final Specification spec;
-	static boolean NEVER;
+	public static boolean NEVER;
 	static boolean LTSMIN_LTL = false;
 
 	private LTSminDebug debug;
@@ -173,19 +171,17 @@ public class LTSminTreeWalker {
 
 	public static class Options {
 	    public Options(boolean verbose, boolean no_gm, boolean must_write,
-	                   boolean cnf, boolean nonever,
+	                   boolean cnf,
 	                   boolean unless_java_semantics, boolean no_atomic,
 	                   boolean total) {
 	        this.verbose = verbose;
 	        this.no_gm = no_gm;
 	        this.must_write = must_write;
 	        this.cnf = cnf;
-	        this.nonever = nonever;
 	        this.unless_java_semantics = unless_java_semantics;
 	        this.no_atomic = no_atomic;
 	        this.total = total;
         }
-	    public boolean nonever = false;
         public boolean verbose = false;
 	    public boolean no_gm = false;
 	    public boolean must_write = false;
@@ -206,7 +202,7 @@ public class LTSminTreeWalker {
                                          Expression progress) {
 		this.debug = new LTSminDebug(opts.verbose);
 		UNLESS_JAVA_SEMANTICS = opts.unless_java_semantics;
-
+		
         debug.say("Generating next-state function ...");
         debug.say_indent++;
         LTSminProgress report = new LTSminProgress(debug).startTimer();
@@ -485,7 +481,7 @@ public class LTSminTreeWalker {
 				id++;
 			}
 		}
-		if (null != spec.getNever()) {
+		if (NEVER) {
 			Proctype never = spec.getNever();
 			ProcInstance n = instantiate(never, -1, -1);
 			spec.setNever(n);
@@ -1249,7 +1245,7 @@ public class LTSminTreeWalker {
         }
         
         if (never_t.getTo().isInAtomic() || never_t.getFrom().isInAtomic())
-    		throw new AssertionError("Atomic in never claim not implemented");
+    			throw new AssertionError("Atomic in never claim not implemented");
 		lt.addGuard(pcGuard(never_t.getFrom(), spec.getNever()));
         createEnabledGuard(never_t, lt);
         lt.addAction(assign(spec.getNever().getPC(),