[parser] Only validate expressions when we have to

Since ValidateExpression just throws the only queued (first) expression error,
we can delay throwing it until the latest possible moment. That's right before
the matching expression classifier dies (goes out of scope or accumulates).

Change-Id: I4538de333b789ae786278b94b76b4799ccdf4903
Reviewed-on: https://chromium-review.googlesource.com/c/1286678
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56785}

src/parsing/parser-base.h

@@ -1080,9 +1080,7 @@ class ParserBase {
       bool* is_rest_property, bool* ok);
   ExpressionListT ParseArguments(bool* has_spread, bool maybe_arrow, bool* ok);
   ExpressionListT ParseArguments(bool* has_spread, bool* ok) {
-    ExpressionListT result = ParseArguments(has_spread, false, ok);
-    ValidateExpression(CHECK_OK_CUSTOM(NullExpressionList));
-    return result;
+    return ParseArguments(has_spread, false, ok);
   }
 
   ExpressionT ParseAssignmentExpression(bool accept_IN, bool* ok);
@@ -2917,7 +2915,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseYieldExpression(
         V8_FALLTHROUGH;
       default:
         expression = ParseAssignmentExpression(accept_IN, CHECK_OK);
-        ValidateExpression(CHECK_OK);
         break;
     }
   }
@@ -2966,7 +2963,6 @@ ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
                                                bool accept_IN, int pos,
                                                bool* ok) {
   SourceRange then_range, else_range;
-  ValidateExpression(CHECK_OK);
   BindingPatternUnexpectedToken();
   ArrowFormalParametersUnexpectedToken();
 
@@ -2981,7 +2977,6 @@ ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
     left = ParseAssignmentExpression(true, CHECK_OK);
     AccumulateNonBindingPatternErrors();
   }
-  ValidateExpression(CHECK_OK);
   ExpressionT right;
   {
     SourceRangeScope range_scope(scanner(), &else_range);
@@ -2990,7 +2985,6 @@ ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
     right = ParseAssignmentExpression(accept_IN, CHECK_OK);
     AccumulateNonBindingPatternErrors();
   }
-  ValidateExpression(CHECK_OK);
   ExpressionT expr = factory()->NewConditional(expression, left, right, pos);
   impl()->RecordConditionalSourceRange(expr, then_range, else_range);
   return expr;
@@ -3008,8 +3002,6 @@ ParserBase<Impl>::ParseBinaryContinuation(ExpressionT x, int prec, int prec1,
   do {
     // prec1 >= 4
     while (Token::Precedence(peek()) == prec1) {
-      ValidateExpression(CHECK_OK);
-
       SourceRange right_range;
       int pos = peek_position();
       ExpressionT y;
@@ -3022,7 +3014,6 @@ ParserBase<Impl>::ParseBinaryContinuation(ExpressionT x, int prec, int prec1,
         const int next_prec = is_right_associative ? prec1 : prec1 + 1;
         y = ParseBinaryExpression(next_prec, accept_IN, CHECK_OK);
       }
-      ValidateExpression(CHECK_OK);
 
       // For now we distinguish between comparisons and other binary
       // operations.  (We could combine the two and get rid of this
@@ -3085,7 +3076,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseUnaryOpExpression(
   }
 
   ExpressionT expression = ParseUnaryExpression(CHECK_OK);
-  ValidateExpression(CHECK_OK);
 
   if (op == Token::DELETE) {
     if (impl()->IsIdentifier(expression) && is_strict(language_mode())) {
@@ -3124,7 +3114,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePrefixExpression(
       expression, beg_pos, end_position(),
       MessageTemplate::kInvalidLhsInPrefixOp, CHECK_OK);
   impl()->MarkExpressionAsAssigned(expression);
-  ValidateExpression(CHECK_OK);
 
   return factory()->NewCountOperation(op, true /* prefix */, expression,
                                       position());
@@ -3192,7 +3181,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePostfixExpression(
         expression, lhs_beg_pos, end_position(),
         MessageTemplate::kInvalidLhsInPostfixOp, CHECK_OK);
     impl()->MarkExpressionAsAssigned(expression);
-    ValidateExpression(CHECK_OK);
 
     Token::Value next = Next();
     expression =
@@ -3324,7 +3312,6 @@ ParserBase<Impl>::ParseLeftHandSideContinuation(ExpressionT result, bool* ok) {
         break;
     }
   } while (Token::IsPropertyOrCall(peek()));
-  ValidateExpression(CHECK_OK);
   return result;
 }
 
@@ -3370,7 +3357,6 @@ ParserBase<Impl>::ParseMemberWithPresentNewPrefixesExpression(bool* ok) {
   } else {
     result = ParseMemberWithNewPrefixesExpression(CHECK_OK);
   }
-  ValidateExpression(CHECK_OK);
   if (peek() == Token::LPAREN) {
     // NewExpression with arguments.
     bool has_spread;
@@ -3610,7 +3596,6 @@ ParserBase<Impl>::DoParseMemberExpressionContinuation(ExpressionT expression,
       }
     }
   } while (Token::IsProperty(peek()));
-  ValidateExpression(CHECK_OK);
   return expression;
 }
 
@@ -4545,7 +4530,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseTemplateLiteral(
 
     int expr_pos = peek_position();
     ExpressionT expression = ParseExpressionCoverGrammar(true, CHECK_OK);
-    ValidateExpression(CHECK_OK);
     impl()->AddTemplateExpression(&ts, expression);
 
     if (peek() != Token::RBRACE) {