Revert "[parser] Remove RETURN_IF* part 16"

This reverts commit fd22cfc8.

Reason for revert: Breaking MSAN build, see
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/23602

Original change's description:
> [parser] Remove RETURN_IF* part 16
> 
> Bug: v8:8363, v8:7926
> Change-Id: I9f0b9e25cf6b47c8ff32451880e348b92ab3cfaa
> Reviewed-on: https://chromium-review.googlesource.com/c/1309760
> Commit-Queue: Toon Verwaest <verwaest@chromium.org>
> Reviewed-by: Igor Sheludko <ishell@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#57172}

TBR=ishell@chromium.org,verwaest@chromium.org

Change-Id: Ic03a669c1a9598c7bd5ca186d783987e91dca5b5
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8363, v8:7926
Reviewed-on: https://chromium-review.googlesource.com/c/1309828Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57175}

src/ast/ast.h

@@ -449,7 +449,9 @@ class FunctionDeclaration final : public Declaration {
   friend class AstNodeFactory;
 
   FunctionDeclaration(VariableProxy* proxy, FunctionLiteral* fun, int pos)
-      : Declaration(proxy, pos, kFunctionDeclaration), fun_(fun) {}
+      : Declaration(proxy, pos, kFunctionDeclaration), fun_(fun) {
+    DCHECK_NOT_NULL(fun);
+  }
 
   FunctionLiteral* fun_;
 };

src/parsing/parser-base.h

@@ -1547,7 +1547,7 @@ ParserBase<Impl>::ParseAndClassifyIdentifier() {
     if (impl()->IsEvalOrArguments(name)) {
       if (impl()->IsArguments(name) && scope()->ShouldBanArguments()) {
         ReportMessage(MessageTemplate::kArgumentsDisallowedInInitializer);
-        return impl()->EmptyIdentifierString();
+        return impl()->NullIdentifier();
       }
 
       classifier()->RecordStrictModeFormalParameterError(
@@ -1575,7 +1575,7 @@ ParserBase<Impl>::ParseAndClassifyIdentifier() {
     return impl()->GetSymbol();
   } else {
     ReportUnexpectedToken(next);
-    return impl()->EmptyIdentifierString();
+    return impl()->NullIdentifier();
   }
 }
 
@@ -1594,7 +1594,7 @@ ParserBase<Impl>::ParseIdentifierOrStrictReservedWord(
     *is_strict_reserved = true;
   } else {
     ReportUnexpectedToken(next);
-    return impl()->EmptyIdentifierString();
+    return impl()->NullIdentifier();
   }
 
   return impl()->GetSymbol();
@@ -1606,7 +1606,7 @@ typename ParserBase<Impl>::IdentifierT ParserBase<Impl>::ParseIdentifierName() {
   if (!Token::IsAnyIdentifier(next) && next != Token::ESCAPED_KEYWORD &&
       !Token::IsKeyword(next)) {
     ReportUnexpectedToken(next);
-    return impl()->EmptyIdentifierString();
+    return impl()->NullIdentifier();
   }
 
   return impl()->GetSymbol();
@@ -1628,6 +1628,7 @@ ParserBase<Impl>::ParseIdentifierNameOrPrivateName() {
     name = ParseIdentifierName();
     key = factory()->NewStringLiteral(name, pos);
   }
+  RETURN_IF_PARSE_ERROR;
   impl()->PushLiteralName(name);
   return key;
 }
@@ -2130,6 +2131,7 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParsePropertyName(
   if (*kind == ParsePropertyKind::kNotSet) {
     ParsePropertyKindFromToken(peek(), kind);
   }
+  RETURN_IF_PARSE_ERROR;
   impl()->PushLiteralName(*name);
   return is_array_index ? factory()->NewNumberLiteral(index, pos)
                         : factory()->NewStringLiteral(*name, pos);
@@ -2703,6 +2705,8 @@ ParserBase<Impl>::ParseAssignmentExpression(bool accept_IN) {
     }
 
     scope->set_start_position(lhs_beg_pos);
+    // TODO(verwaest): Disable DCHECKs in failure mode?
+    RETURN_IF_PARSE_ERROR;
     impl()->DeclareArrowFunctionFormalParameters(&parameters, expression, loc);
 
     expression =
@@ -3833,6 +3837,8 @@ ParserBase<Impl>::ParseHoistableDeclaration(
   }
 
   FuncNameInferrerState fni_state(&fni_);
+  // TODO(verwaest): Remove once we have FailureIdentifier.
+  RETURN_IF_PARSE_ERROR_CUSTOM(NullStatement);
   impl()->PushEnclosingName(name);
 
   FunctionKind kind = FunctionKindFor(flags);
@@ -3856,6 +3862,7 @@ ParserBase<Impl>::ParseHoistableDeclaration(
                                   !scope()->is_declaration_scope() &&
                                   flags == ParseFunctionFlag::kIsNormal;
 
+  RETURN_IF_PARSE_ERROR_CUSTOM(NullStatement);
   return impl()->DeclareFunction(variable_name, function, mode, pos,
                                  is_sloppy_block_function, names);
 }
@@ -3897,6 +3904,7 @@ typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseClassDeclaration(
   ExpressionT value = ParseClassLiteral(name, scanner()->location(),
                                         is_strict_reserved, class_token_pos);
   int end_pos = position();
+  RETURN_IF_PARSE_ERROR_CUSTOM(NullStatement);
   return impl()->DeclareClass(variable_name, value, names, class_token_pos,
                               end_pos);
 }
@@ -4130,7 +4138,7 @@ ParserBase<Impl>::ParseArrowFunctionLiteral(
   base::ElapsedTimer timer;
   if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
 
-  DCHECK_IMPLIES(!has_error(), peek() == Token::ARROW);
+  DCHECK_EQ(Token::ARROW, peek());
   if (scanner_->HasLineTerminatorBeforeNext()) {
     // ASI inserts `;` after arrow parameters if a line terminator is found.
     // `=> ...` is never a valid expression, so report as syntax error.

src/parsing/parser.cc

@@ -2436,7 +2436,7 @@ void Parser::AddArrowFunctionFormalParameters(
 void Parser::DeclareArrowFunctionFormalParameters(
     ParserFormalParameters* parameters, Expression* expr,
     const Scanner::Location& params_loc) {
-  if (expr->IsEmptyParentheses() || has_error()) return;
+  if (expr->IsEmptyParentheses()) return;
 
   AddArrowFunctionFormalParameters(parameters, expr, params_loc.end_pos);
 
@@ -2446,8 +2446,7 @@ void Parser::DeclareArrowFunctionFormalParameters(
   }
 
   DeclareFormalParameters(parameters);
-  DCHECK_IMPLIES(parameters->is_simple,
-                 parameters->scope->has_simple_parameters());
+  DCHECK_EQ(parameters->is_simple, parameters->scope->has_simple_parameters());
 }
 
 void Parser::PrepareGeneratorVariables() {

src/parsing/parser.h

@@ -862,6 +862,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
   V8_INLINE VariableProxy* ExpressionFromIdentifier(
       const AstRawString* name, int start_position,
       InferName infer = InferName::kYes) {
+    if (has_error()) return nullptr;
     if (infer == InferName::kYes) {
       fni_.PushVariableName(name);
     }