Remove extraneous ';' (empty statement), remove unnecessary null checks and dead code

tool/src/org/antlr/v4/codegen/model/OutputModelObject.java

@@ -37,7 +37,7 @@ public abstract class OutputModelObject {
 	public OutputModelFactory factory;
 	public GrammarAST ast;
 
-	public OutputModelObject() {;}
+	public OutputModelObject() {}
 
 	public OutputModelObject(OutputModelFactory factory) { this(factory, null); }
 

tool/src/org/antlr/v4/parse/GrammarASTAdaptor.java

@@ -39,7 +39,7 @@ import org.antlr.v4.tool.ast.TerminalAST;
 
 public class GrammarASTAdaptor extends CommonTreeAdaptor {
     org.antlr.runtime.CharStream input; // where we can find chars ref'd by tokens in tree
-    public GrammarASTAdaptor() { ; }
+    public GrammarASTAdaptor() { }
     public GrammarASTAdaptor(org.antlr.runtime.CharStream input) { this.input = input; }
 
     @Override

tool/src/org/antlr/v4/parse/v4ParserException.java

@@ -35,7 +35,7 @@ import org.antlr.runtime.*;
 public class v4ParserException extends RecognitionException {
 	public String msg;
 	/** Used for remote debugger deserialization */
-	public v4ParserException() {;}
+	public v4ParserException() {}
 
 	public v4ParserException(String msg, IntStream input) {
 		super(input);

tool/src/org/antlr/v4/semantics/ActionSniffer.java

@@ -107,11 +107,11 @@ public class ActionSniffer extends BlankActionSplitterListener {
 
 	public void trackRef(Token x) {
 		List<TerminalAST> xRefs = alt.tokenRefs.get(x.getText());
-		if ( alt!=null && xRefs!=null ) {
+		if ( xRefs!=null ) {
 			alt.tokenRefsInActions.map(x.getText(), node);
 		}
 		List<GrammarAST> rRefs = alt.ruleRefs.get(x.getText());
-		if ( alt!=null && rRefs!=null ) {
+		if ( rRefs!=null ) {
 			alt.ruleRefsInActions.map(x.getText(), node);
 		}
 	}

tool/src/org/antlr/v4/semantics/SemanticPipeline.java

@@ -82,7 +82,7 @@ public class SemanticPipeline {
 		basics.process();
 
 		// don't continue if we get errors in this basic check
-		if ( false ) return;
+		//if ( false ) return;
 
 		// TRANSFORM LEFT-RECURSIVE RULES
 		LeftRecursiveRuleTransformer lrtrans =

tool/src/org/antlr/v4/tool/Attribute.java

@@ -48,7 +48,7 @@ public class Attribute {
 	/** Who contains us? */
 	public AttributeDict dict;
 
-    public Attribute() {;}
+    public Attribute() {}
 
     public Attribute(String name) { this(name,null); }