Remove destructuring and default arguments runtime flags

src/parsing/parser.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-rewriter.h"
 #include "src/ast/ast-expression-visitor.h"
@@ skipping 761 matching lines @@
       parsing_on_main_thread_(true) {
   // Even though we were passed ParseInfo, we should not store it in
   // Parser - this makes sure that Isolate is not accidentally accessed via
   // ParseInfo during background parsing.
   DCHECK(!info->script().is_null() || info->source_stream() != NULL);
   set_allow_lazy(info->allow_lazy_parsing());
   set_allow_natives(FLAG_allow_natives_syntax || info->is_native());
   set_allow_harmony_sloppy(FLAG_harmony_sloppy);
   set_allow_harmony_sloppy_function(FLAG_harmony_sloppy_function);
   set_allow_harmony_sloppy_let(FLAG_harmony_sloppy_let);
-  set_allow_harmony_default_parameters(FLAG_harmony_default_parameters);
-  set_allow_harmony_destructuring_bind(FLAG_harmony_destructuring_bind);
-  set_allow_harmony_destructuring_assignment(
-      FLAG_harmony_destructuring_assignment);
   set_allow_legacy_const(FLAG_legacy_const);
   set_allow_harmony_do_expressions(FLAG_harmony_do_expressions);
   set_allow_harmony_function_name(FLAG_harmony_function_name);
   set_allow_harmony_function_sent(FLAG_harmony_function_sent);
   set_allow_harmony_restrictive_declarations(
       FLAG_harmony_restrictive_declarations);
   for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
        ++feature) {
     use_counts_[feature] = 0;
   }
@@ skipping 138 matching lines @@
     if (ok && is_strict(language_mode())) {
       CheckStrictOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
     }
     if (ok && is_sloppy(language_mode()) && allow_harmony_sloppy_function()) {
       // TODO(littledan): Function bindings on the global object that modify
       // pre-existing bindings should be made writable, enumerable and
       // nonconfigurable if possible, whereas this code will leave attributes
       // unchanged if the property already exists.
       InsertSloppyBlockFunctionVarBindings(scope, &ok);
     }
-    if (ok && (is_strict(language_mode()) || allow_harmony_sloppy() ||
-               allow_harmony_destructuring_bind())) {
+    if (ok) {
       CheckConflictingVarDeclarations(scope_, &ok);
     }
 
     if (ok && info->parse_restriction() == ONLY_SINGLE_FUNCTION_LITERAL) {
       if (body->length() != 1 ||
           !body->at(0)->IsExpressionStatement() ||
           !body->at(0)->AsExpressionStatement()->
               expression()->IsFunctionLiteral()) {
         ReportMessage(MessageTemplate::kSingleFunctionLiteral);
         ok = false;
@@ skipping 1360 matching lines @@
   do {
     FuncNameInferrer::State fni_state(fni_);
 
     // Parse name.
     if (!first_declaration) Consume(Token::COMMA);
 
     Expression* pattern;
     int decl_pos = peek_position();
     {
       ExpressionClassifier pattern_classifier(this);
-      Token::Value next = peek();
       pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
       ValidateBindingPattern(&pattern_classifier, CHECK_OK);
       if (IsLexicalVariableMode(parsing_result->descriptor.mode)) {
         ValidateLetPattern(&pattern_classifier, CHECK_OK);
       }
-      if (!allow_harmony_destructuring_bind() && !pattern->IsVariableProxy()) {
-        ReportUnexpectedToken(next);
-        *ok = false;
-        return nullptr;
-      }
     }
 
     Scanner::Location variable_loc = scanner()->location();
     const AstRawString* single_name =
         pattern->IsVariableProxy() ? pattern->AsVariableProxy()->raw_name()
                                    : nullptr;
     if (single_name != nullptr) {
       if (fni_ != NULL) fni_->PushVariableName(single_name);
     }
 
@@ skipping 793 matching lines @@
 
 void Parser::InitializeForEachStatement(ForEachStatement* stmt,
                                         Expression* each, Expression* subject,
                                         Statement* body) {
   ForOfStatement* for_of = stmt->AsForOfStatement();
   if (for_of != NULL) {
     InitializeForOfStatement(for_of, each, subject, body,
                              RelocInfo::kNoPosition);
   } else {
     if (each->IsArrayLiteral() || each->IsObjectLiteral()) {
-      DCHECK(allow_harmony_destructuring_assignment());
       Variable* temp =
           scope_->NewTemporary(ast_value_factory()->empty_string());
       VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
       Expression* assign_each = PatternRewriter::RewriteDestructuringAssignment(
           this, factory()->NewAssignment(Token::ASSIGN, each, temp_proxy,
                                          RelocInfo::kNoPosition),
           scope_);
       auto block =
           factory()->NewBlock(nullptr, 2, false, RelocInfo::kNoPosition);
       block->statements()->Add(factory()->NewExpressionStatement(
@@ skipping 55 matching lines @@
   // each = result.value
   {
     Expression* value_literal = factory()->NewStringLiteral(
         ast_value_factory()->value_string(), RelocInfo::kNoPosition);
     Expression* result_proxy = factory()->NewVariableProxy(result);
     Expression* result_value = factory()->NewProperty(
         result_proxy, value_literal, RelocInfo::kNoPosition);
     assign_each = factory()->NewAssignment(Token::ASSIGN, each, result_value,
                                            RelocInfo::kNoPosition);
     if (each->IsArrayLiteral() || each->IsObjectLiteral()) {
-      DCHECK(allow_harmony_destructuring_assignment());
       assign_each = PatternRewriter::RewriteDestructuringAssignment(
           this, assign_each->AsAssignment(), scope_);
     }
   }
 
   for_of->Initialize(each, iterable, body, iterator, assign_iterator,
                      next_result, result_done, assign_each);
 }
 
 Statement* Parser::DesugarLexicalBindingsInForStatement(
@@ skipping 456 matching lines @@
       Expression* expression = ParseExpression(false, &classifier, CHECK_OK);
       int lhs_end_pos = scanner()->location().end_pos;
       ForEachStatement::VisitMode mode = ForEachStatement::ENUMERATE;
       is_let_identifier_expression =
           expression->IsVariableProxy() &&
           expression->AsVariableProxy()->raw_name() ==
               ast_value_factory()->let_string();
 
       bool is_for_each = CheckInOrOf(&mode, ok);
       if (!*ok) return nullptr;
-      bool is_destructuring =
-          is_for_each && allow_harmony_destructuring_assignment() &&
-          (expression->IsArrayLiteral() || expression->IsObjectLiteral());
+      bool is_destructuring = is_for_each && (expression->IsArrayLiteral() ||
+                                              expression->IsObjectLiteral());
 
       if (is_destructuring) {
         ValidateAssignmentPattern(&classifier, CHECK_OK);
       } else {
         RewriteNonPattern(&classifier, CHECK_OK);
       }
 
       if (is_for_each) {
         if (!is_destructuring) {
           expression = this->CheckAndRewriteReferenceExpression(
@@ skipping 233 matching lines @@
   Expression* initializer = nullptr;
   if (expr->IsVariableProxy()) {
     // When the formal parameter was originally seen, it was parsed as a
     // VariableProxy and recorded as unresolved in the scope.  Here we undo that
     // parse-time side-effect for parameters that are single-names (not
     // patterns; for patterns that happens uniformly in
     // PatternRewriter::VisitVariableProxy).
     parser_->scope_->RemoveUnresolved(expr->AsVariableProxy());
   } else if (expr->IsAssignment()) {
     Assignment* assignment = expr->AsAssignment();
-    DCHECK(parser_->allow_harmony_default_parameters());
     DCHECK(!assignment->is_compound());
     initializer = assignment->value();
     expr = assignment->target();
 
     // TODO(adamk): Only call this if necessary.
     RewriteParameterInitializerScope(parser_->stack_limit(), initializer,
                                      parser_->scope_, parameters->scope);
   }
 
   // TODO(adamk): params_loc.end_pos is not the correct initializer position,
@@ skipping 296 matching lines @@
     ValidateFormalParameters(&formals_classifier, language_mode,
                              allow_duplicate_parameters, CHECK_OK);
 
     if (is_strict(language_mode)) {
       CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
                               CHECK_OK);
     }
     if (is_sloppy(language_mode) && allow_harmony_sloppy_function()) {
       InsertSloppyBlockFunctionVarBindings(scope, CHECK_OK);
     }
-    if (is_strict(language_mode) || allow_harmony_sloppy() ||
-        allow_harmony_destructuring_bind()) {
-      CheckConflictingVarDeclarations(scope, CHECK_OK);
-    }
+    CheckConflictingVarDeclarations(scope, CHECK_OK);
 
     if (body) {
       // If body can be inspected, rewrite queued destructuring assignments
       ParserTraits::RewriteDestructuringAssignments();
     }
     has_duplicate_parameters =
       !formals_classifier.is_valid_formal_parameter_list_without_duplicates();
   }
 
   FunctionLiteral::ParameterFlag duplicate_parameters =
@@ skipping 398 matching lines @@
   DCHECK_EQ(Token::LBRACE, scanner()->current_token());
 
   if (reusable_preparser_ == NULL) {
     reusable_preparser_ = new PreParser(zone(), &scanner_, ast_value_factory(),
                                         NULL, stack_limit_);
     reusable_preparser_->set_allow_lazy(true);
 #define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
     SET_ALLOW(natives);
     SET_ALLOW(harmony_sloppy);
     SET_ALLOW(harmony_sloppy_let);
-    SET_ALLOW(harmony_default_parameters);
-    SET_ALLOW(harmony_destructuring_bind);
-    SET_ALLOW(harmony_destructuring_assignment);
     SET_ALLOW(harmony_do_expressions);
     SET_ALLOW(harmony_function_name);
     SET_ALLOW(harmony_function_sent);
 #undef SET_ALLOW
   }
   PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
       language_mode(), function_state_->kind(), scope_->has_simple_parameters(),
       logger, bookmark);
   if (pre_parse_timer_ != NULL) {
     pre_parse_timer_->Stop();
@@ skipping 746 matching lines @@
     for (int i = begin; i < end; i++) {
       DCHECK(non_patterns_to_rewrite->at(i)->IsRewritableExpression());
       rewriter.Rewrite(non_patterns_to_rewrite->at(i));
     }
     non_patterns_to_rewrite->Rewind(begin);
   }
 }
 
 
 void Parser::RewriteDestructuringAssignments() {
-  if (!allow_harmony_destructuring_assignment()) return;
   const auto& assignments =
       function_state_->destructuring_assignments_to_rewrite();
   for (int i = assignments.length() - 1; i >= 0; --i) {
     // Rewrite list in reverse, so that nested assignment patterns are rewritten
     // correctly.
     const DestructuringAssignment& pair = assignments.at(i);
     RewritableExpression* to_rewrite =
         pair.assignment->AsRewritableExpression();
     DCHECK_NOT_NULL(to_rewrite);
     if (!to_rewrite->is_rewritten()) {
@@ skipping 1327 matching lines @@
                         try_block, target);
     final_loop = target;
   }
 
   return final_loop;
 }
 
 
 }  // namespace internal
 }  // namespace v8