Add supertype to swift nodes

pmd-core/src/main/java/net/sourceforge/pmd/lang/ast/impl/antlr4/AntlrBaseNode.java

@@ -5,19 +5,19 @@
 package net.sourceforge.pmd.lang.ast.impl.antlr4;
 
 import org.antlr.v4.runtime.ParserRuleContext;
+import org.antlr.v4.runtime.tree.ParseTree;
 
 import net.sourceforge.pmd.util.DataMap;
 import net.sourceforge.pmd.util.DataMap.DataKey;
 
-public abstract class AntlrBaseNode extends ParserRuleContext implements AntlrNode {
+public abstract class AntlrBaseNode<I extends AntlrBaseNode<I>> extends ParserRuleContext implements AntlrNode {
 
     private final DataMap<DataKey<?, ?>> userData = DataMap.newDataMap();
 
     /**
      * Constructor required by {@link ParserRuleContext}
      */
-    @SuppressWarnings("unused")
-    public AntlrBaseNode() {
+    protected AntlrBaseNode() {
         // Nothing to be done
     }
 
@@ -27,8 +27,7 @@ public abstract class AntlrBaseNode extends ParserRuleContext implements AntlrNo
      * @param parent The parent
      * @param invokingStateNumber the invokingState defined by {@link org.antlr.v4.runtime.RuleContext} parent
      */
-    @SuppressWarnings("unused")
-    public AntlrBaseNode(final ParserRuleContext parent, final int invokingStateNumber) {
+    protected AntlrBaseNode(final ParserRuleContext parent, final int invokingStateNumber) {
         super(parent, invokingStateNumber);
     }
 
@@ -70,15 +69,17 @@ public abstract class AntlrBaseNode extends ParserRuleContext implements AntlrNo
     }
 
     @Override
-    public AntlrNode getChild(int i) {
-        return (AntlrNode) super.getChild(i);
+    public I getChild(int i) {
+        return cast(super.getChild(i));
     }
 
     @Override
-    public AntlrBaseNode getParent() {
-        return (AntlrBaseNode) super.getParent();
+    public I getParent() {
+        return cast(super.getParent());
     }
 
+    protected abstract I cast(ParseTree o);
+
     @Override
     public int getNumChildren() {
         return getChildCount();

pmd-swift/src/main/antlr4/net/sourceforge/pmd/lang/swift/ast/Swift.g4

@@ -54,7 +54,7 @@ import net.sourceforge.pmd.lang.ast.impl.antlr4.*;
 }
 
 options {
-    contextSuperClass = AntlrBaseNode;
+    contextSuperClass = SwiftNode;
     superClass = PmdAntlrParserBase;
 }
 

pmd-swift/src/main/java/net/sourceforge/pmd/lang/swift/ast/SwiftNode.java

@@ -0,0 +1,29 @@
+/*
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.swift.ast;
+
+import org.antlr.v4.runtime.ParserRuleContext;
+import org.antlr.v4.runtime.tree.ParseTree;
+
+import net.sourceforge.pmd.lang.ast.impl.antlr4.AntlrBaseNode;
+
+/**
+ * Supertype of all swift nodes.
+ */
+public abstract class SwiftNode extends AntlrBaseNode<SwiftNode> {
+
+    protected SwiftNode() {
+        super();
+    }
+
+    protected SwiftNode(final ParserRuleContext parent, final int invokingStateNumber) {
+        super(parent, invokingStateNumber);
+    }
+
+    @Override
+    protected SwiftNode cast(ParseTree o) {
+        return (SwiftNode) o;
+    }
+}