[parser] Make IsValidPattern a range-check over Object/Array literal

Change-Id: I53fc5b8ff39c91fe509e292cf32f54ff4f8e2eb7
Reviewed-on: https://chromium-review.googlesource.com/c/1335694
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57508}

src/ast/ast.h

@@ -250,6 +250,11 @@ class Expression : public AstNode {
 
   bool IsCompileTimeValue();
 
+  bool IsValidPattern() {
+    STATIC_ASSERT(kObjectLiteral + 1 == kArrayLiteral);
+    return IsInRange(node_type(), kObjectLiteral, kArrayLiteral);
+  }
+
  protected:
   Expression(int pos, NodeType type) : AstNode(pos, type) {}
 

src/parsing/parser-base.h

@@ -1211,10 +1211,6 @@ class ParserBase {
     return true;
   }
 
-  bool IsValidPattern(ExpressionT expression) {
-    return expression->IsObjectLiteral() || expression->IsArrayLiteral();
-  }
-
   // Due to hoisting, the value of a 'var'-declared variable may actually change
   // even if the code contains only the "initial" assignment, namely when that
   // assignment occurs inside a loop.  For example:
@@ -2689,7 +2685,7 @@ ParserBase<Impl>::ParseAssignmentExpression() {
   }
 
   // Destructuring assignmment.
-  if (V8_UNLIKELY(IsValidPattern(expression) && op == Token::ASSIGN)) {
+  if (V8_UNLIKELY(expression->IsValidPattern() && op == Token::ASSIGN)) {
     ValidateAssignmentPattern();
 
     // This is definitely not an expression so don't accumulate
@@ -4453,7 +4449,7 @@ bool ParserBase<Impl>::IsValidReferenceExpression(ExpressionT expression) {
 template <typename Impl>
 void ParserBase<Impl>::CheckDestructuringElement(ExpressionT expression,
                                                  int begin, int end) {
-  if (!IsValidPattern(expression) && !expression->IsAssignment() &&
+  if (!expression->IsValidPattern() && !expression->IsAssignment() &&
       !IsValidReferenceExpression(expression)) {
     if (expression->IsProperty()) ValidateExpression();
     classifier()->RecordAssignmentPatternError(

src/parsing/preparser.h

@@ -236,6 +236,12 @@ class PreParserExpression {
     return TypeField::decode(code_) == kArrayLiteralExpression;
   }
 
+  bool IsValidPattern() const {
+    STATIC_ASSERT(kObjectLiteralExpression + 1 == kArrayLiteralExpression);
+    return IsInRange(TypeField::decode(code_),
+                     kObjectLiteralExpression, kArrayLiteralExpression);
+  }
+
   bool IsStringLiteral() const {
     return TypeField::decode(code_) == kStringLiteralExpression;
   }