[GR-40878] Avoid appending a statement for an always-true delete expression.

PullRequest: js/2582

Author: woess

graal-js/src/com.oracle.js.parser/src/com/oracle/js/parser/Parser.java

@@ -117,7 +117,6 @@
 import java.util.Map;
 import java.util.function.Consumer;
 
-import com.oracle.js.parser.ir.ClassElement;
 import org.graalvm.collections.Pair;
 
 import com.oracle.js.parser.ir.AccessNode;
@@ -129,6 +128,7 @@
 import com.oracle.js.parser.ir.CallNode;
 import com.oracle.js.parser.ir.CaseNode;
 import com.oracle.js.parser.ir.CatchNode;
+import com.oracle.js.parser.ir.ClassElement;
 import com.oracle.js.parser.ir.ClassNode;
 import com.oracle.js.parser.ir.ContinueNode;
 import com.oracle.js.parser.ir.DebuggerNode;
@@ -5848,7 +5848,6 @@ private ParserException invalidLHSError(final Expression lhs) {
      * @return Expression node.
      */
     private Expression unaryExpression(boolean yield, boolean await, CoverExpressionError coverExpression) {
-        final int unaryLine = line;
         final long unaryToken = token;
 
         switch (type) {
@@ -5860,7 +5859,7 @@ private Expression unaryExpression(boolean yield, boolean await, CoverExpression
                     throw error(AbstractParser.message(MSG_UNEXPECTED_TOKEN, type.getNameOrType()));
                 }
 
-                return verifyDeleteExpression(unaryLine, unaryToken, expr);
+                return verifyDeleteExpression(unaryToken, expr);
             }
             case VOID:
             case TYPEOF:
@@ -5913,7 +5912,7 @@ private Expression unaryExpression(boolean yield, boolean await, CoverExpression
         return expression;
     }
 
-    private Expression verifyDeleteExpression(final int unaryLine, final long unaryToken, final Expression expr) {
+    private Expression verifyDeleteExpression(final long unaryToken, final Expression expr) {
         if (expr instanceof BaseNode || expr instanceof IdentNode) {
             if (isStrictMode) {
                 if (expr instanceof IdentNode) {
@@ -5925,10 +5924,8 @@ private Expression verifyDeleteExpression(final int unaryLine, final long unaryT
                     throw error(AbstractParser.message(MSG_STRICT_CANT_DELETE_PRIVATE), unaryToken);
                 }
             }
-            return new UnaryNode(unaryToken, expr);
         }
-        appendStatement(new ExpressionStatement(unaryLine, unaryToken, finish, expr));
-        return LiteralNode.newInstance(unaryToken, finish, true);
+        return new UnaryNode(unaryToken, expr);
     }
 
     private Expression verifyIncDecExpression(final long unaryToken, final TokenType opType, final Expression lhs, final boolean isPostfix) {

graal-js/src/com.oracle.truffle.js.parser/src/com/oracle/truffle/js/parser/GraalJSTranslator.java

@@ -2492,7 +2492,11 @@ private JavaScriptNode enterDeleteIdent(UnaryNode unaryNode) {
             result = varRef.createDeleteNode();
         } else {
             // deleting a non-reference, always returns true
-            result = factory.createDual(context, transform(rhs), factory.createConstantBoolean(true));
+            if (rhs instanceof LiteralNode.PrimitiveLiteralNode<?>) {
+                result = factory.createConstantBoolean(true);
+            } else {
+                result = factory.createDual(context, transform(rhs), factory.createConstantBoolean(true));
+            }
         }
         return tagExpression(result, unaryNode);
     }

graal-js/src/com.oracle.truffle.js.test/js/GR-40878.js

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2022, 2022, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Licensed under the Universal Permissive License v 1.0 as shown at http://oss.oracle.com/licenses/upl.
+ */
+
+/**
+ * Verify correct parsing of a for-in statement with an always-true delete expression as (an invalid) lhs expr.
+ */
+
+load("assert.js");
+
+assertThrows(() => eval('for(x = delete 0 in "") {}'), SyntaxError); // Invalid left side value of for..in loop
+assertThrows(() => eval('for(x = delete 0 of "") {}'), SyntaxError); // Invalid left side value of for..of loop
+assertThrows(() => eval('(async function() { for await(x = delete 0 of "") {}})'), SyntaxError);
+
+eval('for(var x = delete (Math.max([[1]], -14)) in new Array(4)) { this.v2 = x; }');
+assertThrows(() => eval('for(let x = delete (Math.max([[1]], -14)) in new Array(4)) { this.v2 = x; }'));
+eval('for(x = delete 0; !delete true; x = delete "") {}');
+
+assertThrows(() => eval(`
+    (async function() {
+        for await(let b of async function(y) {
+            "use strict";
+            o0.a1[({
+                valueOf: function() {
+                    for(x = delete "" in /x/g ) for (let i = 0; i < 999; i++) {}
+                    return 9;
+                }
+            })];
+        }) for await(let a of /*MARR*/[null]) throw e;
+        eval.message;
+    })`
+), SyntaxError);