Add support for parsing empty statements

Author: waleedyaseen

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Add a formatter option for space around commas in return lists.
 - Add a formatter option for space within return list parenthesis.
 - Add error recovery for statements.
+- Add support for parsing empty statements.
 
 ### Changed
 - The build window will now display internal compiler errors as well.

src/main/gen/io/runescript/plugin/lang/parser/RsParser.java

@@ -43,9 +43,9 @@ static boolean parse_root_(IElementType t, PsiBuilder b, int l) {
   }
 
   public static final TokenSet[] EXTENDS_SETS_ = new TokenSet[] {
-    create_token_set_(ARRAY_VARIABLE_DECLARATION_STATEMENT, ASSIGNMENT_STATEMENT, BLOCK_STATEMENT, EXPRESSION_STATEMENT,
-      IF_STATEMENT, LOCAL_VARIABLE_DECLARATION_STATEMENT, RETURN_STATEMENT, STATEMENT,
-      SWITCH_STATEMENT, WHILE_STATEMENT),
+    create_token_set_(ARRAY_VARIABLE_DECLARATION_STATEMENT, ASSIGNMENT_STATEMENT, BLOCK_STATEMENT, EMPTY_STATEMENT,
+      EXPRESSION_STATEMENT, IF_STATEMENT, LOCAL_VARIABLE_DECLARATION_STATEMENT, RETURN_STATEMENT,
+      STATEMENT, SWITCH_STATEMENT, WHILE_STATEMENT),
     create_token_set_(ARITHMETIC_EXPRESSION, ARITHMETIC_VALUE_EXPRESSION, ARRAY_ACCESS_EXPRESSION, BOOLEAN_LITERAL_EXPRESSION,
       CALC_EXPRESSION, COMMAND_EXPRESSION, CONDITION_EXPRESSION, CONSTANT_EXPRESSION,
       COORD_LITERAL_EXPRESSION, DYNAMIC_EXPRESSION, EXPRESSION, GOSUB_EXPRESSION,
@@ -536,6 +536,18 @@ public static boolean DynamicExpression(PsiBuilder b, int l) {
     return r;
   }
 
+  /* ********************************************************** */
+  // ';'
+  public static boolean EmptyStatement(PsiBuilder b, int l) {
+    if (!recursion_guard_(b, l, "EmptyStatement")) return false;
+    if (!nextTokenIs(b, "<Statement>", SEMICOLON)) return false;
+    boolean r;
+    Marker m = enter_section_(b, l, _NONE_, EMPTY_STATEMENT, "<Statement>");
+    r = consumeToken(b, SEMICOLON);
+    exit_section_(b, l, m, r, false, null);
+    return r;
+  }
+
   /* ********************************************************** */
   // ParExpression
   //              | ArrayAccessExpression
@@ -1253,6 +1265,7 @@ private static boolean Script_6(PsiBuilder b, int l) {
   //             | LocalVariableDeclarationStatement
   //             | AssignmentStatement
   //             | ExpressionStatement
+  //             | EmptyStatement
   public static boolean Statement(PsiBuilder b, int l) {
     if (!recursion_guard_(b, l, "Statement")) return false;
     boolean r;
@@ -1266,6 +1279,7 @@ public static boolean Statement(PsiBuilder b, int l) {
     if (!r) r = LocalVariableDeclarationStatement(b, l + 1);
     if (!r) r = AssignmentStatement(b, l + 1);
     if (!r) r = ExpressionStatement(b, l + 1);
+    if (!r) r = EmptyStatement(b, l + 1);
     exit_section_(b, l, m, r, false, null);
     return r;
   }

src/main/gen/io/runescript/plugin/lang/psi/RsElementTypes.java

@@ -25,6 +25,7 @@ public interface RsElementTypes {
   IElementType CONSTANT_EXPRESSION = new RsElementType("CONSTANT_EXPRESSION");
   IElementType COORD_LITERAL_EXPRESSION = new RsElementType("COORD_LITERAL_EXPRESSION");
   IElementType DYNAMIC_EXPRESSION = new RsElementType("DYNAMIC_EXPRESSION");
+  IElementType EMPTY_STATEMENT = new RsElementType("EMPTY_STATEMENT");
   IElementType EXPRESSION = new RsElementType("EXPRESSION");
   IElementType EXPRESSION_STATEMENT = new RsElementType("EXPRESSION_STATEMENT");
   IElementType GOSUB_EXPRESSION = new RsElementType("GOSUB_EXPRESSION");
@@ -156,6 +157,9 @@ else if (type == COORD_LITERAL_EXPRESSION) {
       else if (type == DYNAMIC_EXPRESSION) {
         return new RsDynamicExpressionImpl(node);
       }
+      else if (type == EMPTY_STATEMENT) {
+        return new RsEmptyStatementImpl(node);
+      }
       else if (type == EXPRESSION_STATEMENT) {
         return new RsExpressionStatementImpl(node);
       }

src/main/gen/io/runescript/plugin/lang/psi/RsEmptyStatement.java

@@ -0,0 +1,13 @@
+// This class is automatically generated. Do not edit.
+package io.runescript.plugin.lang.psi;
+
+import java.util.List;
+import org.jetbrains.annotations.*;
+import com.intellij.psi.PsiElement;
+
+public interface RsEmptyStatement extends RsStatement {
+
+  @NotNull
+  PsiElement getSemicolon();
+
+}

src/main/gen/io/runescript/plugin/lang/psi/RsVisitor.java

@@ -79,6 +79,10 @@ public void visitDynamicExpression(@NotNull RsDynamicExpression o) {
     // visitNamedElement(o);
   }
 
+  public void visitEmptyStatement(@NotNull RsEmptyStatement o) {
+    visitStatement(o);
+  }
+
   public void visitExpression(@NotNull RsExpression o) {
     visitPsiElement(o);
   }

src/main/gen/io/runescript/plugin/lang/psi/impl/RsEmptyStatementImpl.java

@@ -0,0 +1,36 @@
+// This class is automatically generated. Do not edit.
+package io.runescript.plugin.lang.psi.impl;
+
+import java.util.List;
+import org.jetbrains.annotations.*;
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiElementVisitor;
+import com.intellij.psi.util.PsiTreeUtil;
+import static io.runescript.plugin.lang.psi.RsElementTypes.*;
+import io.runescript.plugin.lang.psi.*;
+
+public class RsEmptyStatementImpl extends RsStatementImpl implements RsEmptyStatement {
+
+  public RsEmptyStatementImpl(@NotNull ASTNode node) {
+    super(node);
+  }
+
+  @Override
+  public void accept(@NotNull RsVisitor visitor) {
+    visitor.visitEmptyStatement(this);
+  }
+
+  @Override
+  public void accept(@NotNull PsiElementVisitor visitor) {
+    if (visitor instanceof RsVisitor) accept((RsVisitor)visitor);
+    else super.accept(visitor);
+  }
+
+  @Override
+  @NotNull
+  public PsiElement getSemicolon() {
+    return notNullChild(findChildByType(SEMICOLON));
+  }
+
+}

src/main/grammars/RuneScript.bnf

@@ -95,6 +95,7 @@ Statement ::= BlockStatement
             | LocalVariableDeclarationStatement
             | AssignmentStatement
             | ExpressionStatement
+            | EmptyStatement
 
 BlockStatement ::= '{' StatementList '}'
 IfStatement ::= IF '(' LogicalOrWrapper ')' Statement (ELSE Statement)? {
@@ -137,6 +138,7 @@ private AssignableExpression ::= ArrayAccessExpression | LocalVariableExpression
 ExpressionStatement ::= Expression ';' {
     pin=1
 }
+EmptyStatement ::= ';'
 
 // Arithmetic & Bitwise Expressions
 

src/main/kotlin/io/runescript/plugin/ide/codeInsight/controlFlow/RsControlFlowBuilder.kt

@@ -147,6 +147,10 @@ class RsControlFlowBuilder : ControlFlowBuilder() {
             addInstruction(o)
         }
 
+        override fun visitEmptyStatement(o: RsEmptyStatement) {
+            addInstruction(o)
+        }
+
         override fun visitIfStatement(o: RsIfStatement) {
             // ------------------------
             // Case 1:false statement is not present

src/main/kotlin/io/runescript/plugin/lang/psi/type/inference/RsTypeInferenceVisitor.kt

@@ -369,6 +369,10 @@ class RsTypeInferenceVisitor(private val myInferenceData: RsTypeInference) : RsV
         o.expression.accept(this)
     }
 
+    override fun visitEmptyStatement(o: RsEmptyStatement) {
+        // Do nothing.
+    }
+
     override fun visitSwitchStatement(o: RsSwitchStatement) {
         val type = RsPrimitiveType.lookupReferencable(o.switch.text.substring("switch_".length))
         val expression = o.expression