Unreachable Code

src/main/java/ch/njol/skript/ScriptLoader.java

@@ -48,6 +48,7 @@
 import org.bukkit.event.Event;
 import org.eclipse.jdt.annotation.Nullable;
 import org.skriptlang.skript.lang.script.Script;
+import org.skriptlang.skript.lang.script.ScriptWarning;
 import org.skriptlang.skript.lang.structure.Structure;
 
 import java.io.File;
@@ -949,9 +950,10 @@ public static ArrayList<TriggerItem> loadItems(SectionNode node) {
 
 		if (Skript.debug())
 			parser.setIndentation(parser.getIndentation() + "    ");
-		
+
 		ArrayList<TriggerItem> items = new ArrayList<>();
 
+		boolean executionStops = false;
 		for (Node subNode : node) {
 			parser.setNode(subNode);
 
@@ -962,10 +964,11 @@ public static ArrayList<TriggerItem> loadItems(SectionNode node) {
 			if (!SkriptParser.validateLine(expr))
 				continue;
 
+			TriggerItem item;
 			if (subNode instanceof SimpleNode) {
 				long start = System.currentTimeMillis();
-				Statement stmt = Statement.parse(expr, items, "Can't understand this condition/effect: " + expr);
-				if (stmt == null)
+				item = Statement.parse(expr, items, "Can't understand this condition/effect: " + expr);
+				if (item == null)
 					continue;
 				long requiredTime = SkriptConfig.longParseTimeWarningThreshold.value().getMilliSeconds();
 				if (requiredTime > 0) {
@@ -978,34 +981,44 @@ public static ArrayList<TriggerItem> loadItems(SectionNode node) {
 				}
 
 				if (Skript.debug() || subNode.debug())
-					Skript.debug(SkriptColor.replaceColorChar(parser.getIndentation() + stmt.toString(null, true)));
+					Skript.debug(SkriptColor.replaceColorChar(parser.getIndentation() + item.toString(null, true)));
 
-				items.add(stmt);
+				items.add(item);
 			} else if (subNode instanceof SectionNode) {
 				TypeHints.enterScope(); // Begin conditional type hints
 
-				Section section = Section.parse(expr, "Can't understand this section: " + expr, (SectionNode) subNode, items);
-				if (section == null)
+				item = Section.parse(expr, "Can't understand this section: " + expr, (SectionNode) subNode, items);
+				if (item == null)
 					continue;
 
 				if (Skript.debug() || subNode.debug())
-					Skript.debug(SkriptColor.replaceColorChar(parser.getIndentation() + section.toString(null, true)));
+					Skript.debug(SkriptColor.replaceColorChar(parser.getIndentation() + item.toString(null, true)));
 
-				items.add(section);
+				items.add(item);
 
 				// Destroy these conditional type hints
 				TypeHints.exitScope();
+			} else {
+				continue;
+			}
+
+			if (executionStops
+					&& !SkriptConfig.disableUnreachableCodeWarnings.value()
+					&& parser.isActive()
+					&& !parser.getCurrentScript().suppressesWarning(ScriptWarning.UNREACHABLE_CODE)) {
+				Skript.warning("Unreachable code. The previous statement stops further execution.");
 			}
+			executionStops = item.executionIntent() != null;
 		}
-		
+
 		for (int i = 0; i < items.size() - 1; i++)
 			items.get(i).setNext(items.get(i + 1));
 
 		parser.setNode(node);
-		
+
 		if (Skript.debug())
 			parser.setIndentation(parser.getIndentation().substring(0, parser.getIndentation().length() - 4));
-		
+
 		return items;
 	}
 

src/main/java/ch/njol/skript/SkriptConfig.java

@@ -174,6 +174,7 @@ public static String formatDate(final long timestamp) {
 	public static final Option<Boolean> disableMissingAndOrWarnings = new Option<>("disable variable missing and/or warnings", false);
 	public static final Option<Boolean> disableVariableStartingWithExpressionWarnings =
 		new Option<>("disable starting a variable's name with an expression warnings", false);
+	public static final Option<Boolean> disableUnreachableCodeWarnings = new Option<>("disable unreachable code warnings", false);
 
 	@Deprecated
 	public static final Option<Boolean> enableScriptCaching = new Option<>("enable script caching", false)

src/main/java/ch/njol/skript/effects/EffContinue.java

@@ -23,17 +23,15 @@
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
-import ch.njol.skript.lang.Effect;
-import ch.njol.skript.lang.Expression;
-import ch.njol.skript.lang.Literal;
-import ch.njol.skript.lang.LoopSection;
+import ch.njol.skript.lang.*;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
-import ch.njol.skript.lang.TriggerItem;
 import ch.njol.util.Kleenean;
 import ch.njol.util.StringUtils;
 import org.bukkit.event.Event;
-import org.eclipse.jdt.annotation.Nullable;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.UnknownNullability;
 
+import java.util.ArrayList;
 import java.util.List;
 
 @Name("Continue")
@@ -65,35 +63,56 @@ public class EffContinue extends Effect {
 		);
 	}
 
-	@SuppressWarnings("NotNullFieldNotInitialized")
-	private LoopSection loop;
-	@SuppressWarnings("NotNullFieldNotInitialized")
-	private List<LoopSection> innerLoops;
+	private @UnknownNullability LoopSection loop;
+	private @UnknownNullability List<LoopSection> innerLoops;
+	private int breakLevels;
 
 	@Override
 	@SuppressWarnings("unchecked")
 	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
-		List<LoopSection> currentLoops = getParser().getCurrentSections(LoopSection.class);
+		List<TriggerSection> sections = getParser().getCurrentSections();
+		innerLoops = new ArrayList<>();
+		int loopLevels = 0;
+		LoopSection lastLoop = null;
 
-		int size = currentLoops.size();
-		if (size == 0) {
-			Skript.error("The 'continue' effect may only be used in loops");
+		int level = matchedPattern == 0 ? -1 : ((Literal<Integer>) exprs[0]).getSingle();
+		if (matchedPattern != 0 && level < 1) {
+			Skript.error("Can't continue the " + StringUtils.fancyOrderNumber(level) + " loop");
 			return false;
 		}
 
-		int level = matchedPattern == 0 ? size : ((Literal<Integer>) exprs[0]).getSingle();
-		if (level < 1) {
-			Skript.error("Can't continue the " + StringUtils.fancyOrderNumber(level) + " loop");
+		for (TriggerSection section : sections) {
+			if (loop != null)
+				breakLevels++;
+            if (!(section instanceof LoopSection loopSection))
+				continue;
+			loopLevels++;
+			if (level == -1) {
+				lastLoop = loopSection;
+			} else if (loopLevels == level) {
+				loop = loopSection;
+				breakLevels++;
+			} else if (loopLevels > level) {
+				innerLoops.add(loopSection);
+			}
+        }
+
+		if (loopLevels == 0) {
+			Skript.error("The 'continue' effect may only be used in loops");
 			return false;
 		}
-		if (level > size) {
+
+		if (level > loopLevels) {
 			Skript.error("Can't continue the " + StringUtils.fancyOrderNumber(level) + " loop as there " +
-				(size == 1 ? "is only 1 loop" : "are only " + size + " loops") + " present");
+				(loopLevels == 1 ? "is only 1 loop" : "are only " + loopLevels + " loops") + " present");
 			return false;
 		}
 
-		loop = currentLoops.get(level - 1);
-		innerLoops = currentLoops.subList(level, size);
+		if (level == -1) {
+			loop = lastLoop;
+			breakLevels++;
+		}
+
 		return true;
 	}
 
@@ -110,9 +129,14 @@ protected TriggerItem walk(Event event) {
 		return loop;
 	}
 
+	@Override
+	public @Nullable ExecutionIntent executionIntent() {
+		return ExecutionIntent.stopSections(breakLevels);
+	}
+
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
-		return "continue";
+		return "continue" + (loop == null ? "" : " the " + StringUtils.fancyOrderNumber(innerLoops.size() + 1) + " loop");
 	}
 
 }

src/main/java/ch/njol/skript/effects/EffExit.java

@@ -23,13 +23,8 @@
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
-import ch.njol.skript.lang.Effect;
-import ch.njol.skript.lang.Expression;
-import ch.njol.skript.lang.SectionExitHandler;
-import ch.njol.skript.lang.LoopSection;
+import ch.njol.skript.lang.*;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
-import ch.njol.skript.lang.TriggerItem;
-import ch.njol.skript.lang.TriggerSection;
 import ch.njol.skript.lang.parser.ParserInstance;
 import ch.njol.skript.log.ErrorQuality;
 import ch.njol.skript.sections.SecConditional;
@@ -51,7 +46,7 @@
 		"\tset loop-block to water"
 })
 @Since("<i>unknown</i> (before 2.1)")
-public class EffExit extends Effect { // TODO [code style] warn user about code after a stop effect
+public class EffExit extends Effect {
 
 	static {
 		Skript.registerEffect(EffExit.class,
@@ -60,15 +55,15 @@ public class EffExit extends Effect { // TODO [code style] warn user about code
 				"(exit|stop) <\\d+> (section|1:loop|2:conditional)s",
 				"(exit|stop) all (section|1:loop|2:conditional)s");
 	}
-	
+
 	private int breakLevels;
-	
+
 	private static final int EVERYTHING = 0;
 	private static final int LOOPS = 1;
 	private static final int CONDITIONALS = 2;
 	private static final String[] names = {"sections", "loops", "conditionals"};
 	private int type;
-	
+
 	@Override
 	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parser) {
 		switch (matchedPattern) {
@@ -99,7 +94,7 @@ public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelaye
 		}
 		return true;
 	}
-	
+
 	private static int numLevels(int type) {
 		List<TriggerSection> currentSections = ParserInstance.get().getCurrentSections();
 		if (type == EVERYTHING)
@@ -111,7 +106,7 @@ private static int numLevels(int type) {
 		}
 		return level;
 	}
-	
+
 	@Override
 	@Nullable
 	protected TriggerItem walk(Event event) {
@@ -123,23 +118,28 @@ protected TriggerItem walk(Event event) {
 				assert false : this;
 				return null;
 			}
-			if (node instanceof SectionExitHandler)
-				((SectionExitHandler) node).exit(event);
+			if (node instanceof SectionExitHandler exitHandler)
+				exitHandler.exit(event);
 
 			if (type == EVERYTHING || type == CONDITIONALS && node instanceof SecConditional || type == LOOPS && (node instanceof LoopSection))
 				i--;
 		}
-		return node instanceof LoopSection ? ((LoopSection) node).getActualNext() : node.getNext();
+		return node instanceof LoopSection ? node.getActualNext() : node.getNext();
 	}
-	
+
 	@Override
 	protected void execute(Event event) {
 		assert false;
 	}
-
+
+	@Override
+	public @Nullable ExecutionIntent executionIntent() {
+		return ExecutionIntent.stopSections(breakLevels);
+	}
+
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
 		return "stop " + breakLevels + " " + names[type];
 	}
-	
+
 }

src/main/java/ch/njol/skript/effects/EffReturn.java

@@ -23,14 +23,9 @@
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
-import ch.njol.skript.lang.Effect;
-import ch.njol.skript.lang.Expression;
-import ch.njol.skript.lang.ReturnHandler;
+import ch.njol.skript.lang.*;
 import ch.njol.skript.lang.ReturnHandler.ReturnHandlerStack;
-import ch.njol.skript.lang.SectionExitHandler;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
-import ch.njol.skript.lang.TriggerItem;
-import ch.njol.skript.lang.TriggerSection;
 import ch.njol.skript.lang.parser.ParserInstance;
 import ch.njol.skript.log.RetainingLogHandler;
 import ch.njol.skript.log.SkriptLogger;
@@ -114,14 +109,14 @@ protected TriggerItem walk(Event event) {
 
 		TriggerSection parent = getParent();
 		while (parent != null && parent != handler) {
-			if (parent instanceof SectionExitHandler)
-				((SectionExitHandler) parent).exit(event);
+			if (parent instanceof SectionExitHandler exitHandler)
+				exitHandler.exit(event);
 
 			parent = parent.getParent();
 		}
 
-		if (handler instanceof SectionExitHandler)
-			((SectionExitHandler) handler).exit(event);
+		if (handler instanceof SectionExitHandler exitHandler)
+			exitHandler.exit(event);
 
 		return null;
 	}
@@ -131,6 +126,11 @@ protected void execute(Event event) {
 		assert false;
 	}
 
+	@Override
+	public ExecutionIntent executionIntent() {
+		return ExecutionIntent.stopTrigger();
+	}
+
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
 		return "return " + value.toString(event, debug);