Introduce LanguageMode, drop StrictMode.

src/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/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
@@ skipping 264 matching lines @@
 
 FunctionLiteral* Parser::DefaultConstructor(bool call_super, Scope* scope,
                                             int pos, int end_pos) {
   int materialized_literal_count = -1;
   int expected_property_count = -1;
   int handler_count = 0;
   int parameter_count = 0;
   const AstRawString* name = ast_value_factory()->empty_string();
 
   Scope* function_scope = NewScope(scope, FUNCTION_SCOPE);
-  function_scope->SetStrictMode(STRICT);
+  function_scope->SetLanguageMode(
+      static_cast<LanguageMode>(scope->language_mode() | STRICT));
   // Set start and end position to the same value
   function_scope->set_start_position(pos);
   function_scope->set_end_position(pos);
   ZoneList<Statement*>* body = NULL;
 
   {
     AstNodeFactory function_factory(ast_value_factory());
     FunctionState function_state(&function_state_, &scope_, function_scope,
                                  &function_factory);
 
@@ skipping 615 matching lines @@
       *scope = Scope::DeserializeScopeChain(info->isolate(), zone(),
                                             *info->context(), *scope);
       // The Scope is backed up by ScopeInfo (which is in the V8 heap); this
       // means the Parser cannot operate independent of the V8 heap. Tell the
       // string table to internalize strings and values right after they're
       // created.
       ast_value_factory()->Internalize(isolate());
     }
     original_scope_ = *scope;
     if (info->is_eval()) {
-      if (!(*scope)->is_script_scope() || info->strict_mode() == STRICT) {
+      if (!(*scope)->is_script_scope() || is_strict(info->language_mode())) {
         *scope = NewScope(*scope, EVAL_SCOPE);
       }
     } else if (info->is_global()) {
       *scope = NewScope(*scope, SCRIPT_SCOPE);
     }
     (*scope)->set_start_position(0);
     // End position will be set by the caller.
 
     // Compute the parsing mode.
     Mode mode = (FLAG_lazy && allow_lazy()) ? PARSE_LAZILY : PARSE_EAGERLY;
     if (allow_natives() || extension_ != NULL ||
         (*scope)->is_eval_scope()) {
       mode = PARSE_EAGERLY;
     }
     ParsingModeScope parsing_mode(this, mode);
 
     // Enters 'scope'.
     AstNodeFactory function_factory(ast_value_factory());
     FunctionState function_state(&function_state_, &scope_, *scope,
                                  &function_factory);
 
-    scope_->SetStrictMode(info->strict_mode());
+    scope_->SetLanguageMode(info->language_mode());
     ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(16, zone());
     bool ok = true;
     int beg_pos = scanner()->location().beg_pos;
     if (info->is_module()) {
       DCHECK(allow_harmony_modules());
       Module* module = ParseModule(&ok);
       if (ok) {
         // TODO(adamk): Do something with returned Module
         CHECK(module);
         body->Add(factory()->NewEmptyStatement(RelocInfo::kNoPosition), zone());
       }
     } else {
       ParseStatementList(body, Token::EOS, info->is_eval(), eval_scope, &ok);
     }
 
-    if (ok && strict_mode() == STRICT) {
+    if (ok && is_strict(language_mode())) {
       CheckStrictOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
     }
 
-    if (ok && allow_harmony_scoping() && strict_mode() == STRICT) {
+    if (ok && allow_harmony_scoping() && is_strict(language_mode())) {
       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("single_function_literal");
         ok = false;
@@ skipping 78 matching lines @@
     Scope* scope = NewScope(scope_, SCRIPT_SCOPE);
     info()->SetScriptScope(scope);
     if (!info()->closure().is_null()) {
       scope = Scope::DeserializeScopeChain(isolate(), zone(),
                                            info()->closure()->context(), scope);
     }
     original_scope_ = scope;
     AstNodeFactory function_factory(ast_value_factory());
     FunctionState function_state(&function_state_, &scope_, scope,
                                  &function_factory);
-    DCHECK(scope->strict_mode() == SLOPPY || info()->strict_mode() == STRICT);
-    DCHECK(info()->strict_mode() == shared_info->strict_mode());
-    scope->SetStrictMode(shared_info->strict_mode());
+    DCHECK(!is_strict(scope->language_mode()) ||
+           is_strict(info()->language_mode()));
+    DCHECK(info()->language_mode() == shared_info->language_mode());
+    scope->SetLanguageMode(shared_info->language_mode());
     FunctionLiteral::FunctionType function_type = shared_info->is_expression()
         ? (shared_info->is_anonymous()
               ? FunctionLiteral::ANONYMOUS_EXPRESSION
               : FunctionLiteral::NAMED_EXPRESSION)
         : FunctionLiteral::DECLARATION;
     bool ok = true;
 
     if (shared_info->is_arrow()) {
       // The first expression being parsed is the parameter list of the arrow
       // function. Setting this avoids prevents ExpressionFromIdentifier()
@@ skipping 57 matching lines @@
     if (directive_prologue) {
       // A shot at a directive.
       ExpressionStatement* e_stat;
       Literal* literal;
       // Still processing directive prologue?
       if ((e_stat = stat->AsExpressionStatement()) != NULL &&
           (literal = e_stat->expression()->AsLiteral()) != NULL &&
           literal->raw_value()->IsString()) {
         // Check "use strict" directive (ES5 14.1) and "use asm" directive. Only
         // one can be present.
-        if (strict_mode() == SLOPPY &&
+        if (!is_strict(language_mode()) &&
             literal->raw_value()->AsString() ==
                 ast_value_factory()->use_strict_string() &&
             token_loc.end_pos - token_loc.beg_pos ==
                 ast_value_factory()->use_strict_string()->length() + 2) {
           // TODO(mstarzinger): Global strict eval calls, need their own scope
           // as specified in ES5 10.4.2(3). The correct fix would be to always
           // add this scope in DoParseProgram(), but that requires adaptations
           // all over the code base, so we go with a quick-fix for now.
           // In the same manner, we have to patch the parsing mode.
           if (is_eval && !scope_->is_eval_scope()) {
             DCHECK(scope_->is_script_scope());
             Scope* scope = NewScope(scope_, EVAL_SCOPE);
             scope->set_start_position(scope_->start_position());
             scope->set_end_position(scope_->end_position());
             scope_ = scope;
             if (eval_scope != NULL) {
               // Caller will correct the positions of the ad hoc eval scope.
               *eval_scope = scope;
             }
             mode_ = PARSE_EAGERLY;
           }
-          scope_->SetStrictMode(STRICT);
+          scope_->SetLanguageMode(
+              static_cast<LanguageMode>(scope_->language_mode() | STRICT));
           // "use strict" is the only directive for now.
           directive_prologue = false;
         } else if (literal->raw_value()->AsString() ==
                        ast_value_factory()->use_asm_string() &&
                    token_loc.end_pos - token_loc.beg_pos ==
                        ast_value_factory()->use_asm_string()->length() + 2) {
           // Store the usage count; The actual use counter on the isolate is
           // incremented after parsing is done.
           ++use_counts_[v8::Isolate::kUseAsm];
           scope_->SetAsmModule();
@@ skipping 20 matching lines @@
   switch (peek()) {
     case Token::FUNCTION:
       return ParseFunctionDeclaration(NULL, ok);
     case Token::CLASS:
       return ParseClassDeclaration(NULL, ok);
     case Token::CONST:
     case Token::VAR:
       return ParseVariableStatement(kStatementListItem, NULL, ok);
     case Token::LET:
       DCHECK(allow_harmony_scoping());
-      if (strict_mode() == STRICT) {
+      if (is_strict(language_mode())) {
         return ParseVariableStatement(kStatementListItem, NULL, ok);
       }
       // Fall through.
     default:
       return ParseStatement(NULL, ok);
   }
 }
 
 
 Statement* Parser::ParseModuleItem(bool* ok) {
@@ skipping 24 matching lines @@
 
   int pos = peek_position();
   // Construct block expecting 16 statements.
   Block* body = factory()->NewBlock(NULL, 16, false, RelocInfo::kNoPosition);
 #ifdef DEBUG
   if (FLAG_print_interface_details) PrintF("# Literal ");
 #endif
   Scope* scope = NewScope(scope_, MODULE_SCOPE);
 
   scope->set_start_position(scanner()->location().beg_pos);
-  scope->SetStrictMode(STRICT);
+  scope->SetLanguageMode(
+      static_cast<LanguageMode>(scope->language_mode() | STRICT));
 
   {
     BlockState block_state(&scope_, scope);
     Target target(&this->target_stack_, body);
 
     while (peek() != Token::EOS) {
       Statement* stat = ParseModuleItem(CHECK_OK);
       if (stat && !stat->IsEmpty()) {
         body->AddStatement(stat, zone());
       }
@@ skipping 460 matching lines @@
       // (Ecma 262 5th Edition, clause 14):
       // SourceElement:
       //    Statement
       //    FunctionDeclaration
       // Common language extension is to allow function declaration in place
       // of any statement. This language extension is disabled in strict mode.
       //
       // In Harmony mode, this case also handles the extension:
       // Statement:
       //    GeneratorDeclaration
-      if (strict_mode() == STRICT) {
+      if (is_strict(language_mode())) {
         ReportMessageAt(scanner()->peek_location(), "strict_function");
         *ok = false;
         return NULL;
       }
       return ParseFunctionDeclaration(NULL, ok);
     }
 
     case Token::DEBUGGER:
       return ParseDebuggerStatement(ok);
 
     case Token::VAR:
       return ParseVariableStatement(kStatement, NULL, ok);
 
     case Token::CONST:
       // In ES6 CONST is not allowed as a Statement, only as a
       // LexicalDeclaration, however we continue to allow it in sloppy mode for
       // backwards compatibility.
-      if (strict_mode() == SLOPPY) {
+      if (!is_strict(language_mode())) {
         return ParseVariableStatement(kStatement, NULL, ok);
       }
 
     // Fall through.
     default:
       return ParseExpressionOrLabelledStatement(labels, ok);
   }
 }
 
 
@@ skipping 47 matching lines @@
       // functions. The function CheckConflictingVarDeclarations checks for
       // var and let bindings from different scopes whereas this is a check for
       // conflicting declarations within the same scope. This check also covers
       // the special case
       //
       // function () { let x; { var x; } }
       //
       // because the var declaration is hoisted to the function scope where 'x'
       // is already bound.
       DCHECK(IsDeclaredVariableMode(var->mode()));
-      if (allow_harmony_scoping() && strict_mode() == STRICT) {
+      if (allow_harmony_scoping() && is_strict(language_mode())) {
         // In harmony we treat re-declarations as early errors. See
         // ES5 16 for a definition of early errors.
         ParserTraits::ReportMessage("var_redeclaration", name);
         *ok = false;
         return;
       }
       Expression* expression = NewThrowTypeError(
           "var_redeclaration", name, declaration->position());
       declaration_scope->SetIllegalRedeclaration(expression);
     } else if (mode == VAR) {
@@ skipping 20 matching lines @@
   declaration_scope->AddDeclaration(declaration);
 
   if (mode == CONST_LEGACY && declaration_scope->is_script_scope()) {
     // For global const variables we bind the proxy to a variable.
     DCHECK(resolve);  // should be set by all callers
     Variable::Kind kind = Variable::NORMAL;
     var = new (zone())
         Variable(declaration_scope, name, mode, true, kind,
                  kNeedsInitialization, kNotAssigned, proxy->interface());
   } else if (declaration_scope->is_eval_scope() &&
-             declaration_scope->strict_mode() == SLOPPY) {
+             !is_strict(declaration_scope->language_mode())) {
     // For variable declarations in a sloppy eval scope the proxy is bound
     // to a lookup variable to force a dynamic declaration using the
     // DeclareLookupSlot runtime function.
     Variable::Kind kind = Variable::NORMAL;
     // TODO(sigurds) figure out if kNotAssigned is OK here
     var = new (zone()) Variable(declaration_scope, name, mode, true, kind,
                                 declaration->initialization(), kNotAssigned,
                                 proxy->interface());
     var->AllocateTo(Variable::LOOKUP, -1);
     resolve = true;
@@ skipping 113 matching lines @@
                            is_generator ? FunctionKind::kGeneratorFunction
                                         : FunctionKind::kNormalFunction,
                            pos, FunctionLiteral::DECLARATION,
                            FunctionLiteral::NORMAL_ARITY, CHECK_OK);
   // Even if we're not at the top-level of the global or a function
   // scope, we treat it as such and introduce the function with its
   // initial value upon entering the corresponding scope.
   // In ES6, a function behaves as a lexical binding, except in
   // a script scope, or the initial scope of eval or another function.
   VariableMode mode =
-      allow_harmony_scoping() && strict_mode() == STRICT &&
-      !(scope_->is_script_scope() || scope_->is_eval_scope() ||
-          scope_->is_function_scope()) ? LET : VAR;
+      allow_harmony_scoping() && is_strict(language_mode()) &&
+              !(scope_->is_script_scope() || scope_->is_eval_scope() ||
+                scope_->is_function_scope())
+          ? LET
+          : VAR;
   VariableProxy* proxy = NewUnresolved(name, mode, Interface::NewValue());
   Declaration* declaration =
       factory()->NewFunctionDeclaration(proxy, mode, fun, scope_, pos);
   Declare(declaration, true, CHECK_OK);
   if (names) names->Add(name, zone());
   return factory()->NewEmptyStatement(RelocInfo::kNoPosition);
 }
 
 
 Statement* Parser::ParseClassDeclaration(ZoneList<const AstRawString*>* names,
                                          bool* ok) {
   // ClassDeclaration ::
   //   'class' Identifier ('extends' LeftHandExpression)? '{' ClassBody '}'
   //
   // A ClassDeclaration
   //
   //   class C { ... }
   //
   // has the same semantics as:
   //
   //   let C = class C { ... };
   //
   // so rewrite it as such.
 
   Expect(Token::CLASS, CHECK_OK);
-  if (!allow_harmony_sloppy() && strict_mode() == SLOPPY) {
+  if (!allow_harmony_sloppy() && !is_strict(language_mode())) {
     ReportMessage("sloppy_lexical");
     *ok = false;
     return NULL;
   }
 
   int pos = position();
   bool is_strict_reserved = false;
   const AstRawString* name =
       ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
   ClassLiteral* value = ParseClassLiteral(name, scanner()->location(),
                                           is_strict_reserved, pos, CHECK_OK);
 
   VariableProxy* proxy = NewUnresolved(name, LET, Interface::NewValue());
   Declaration* declaration =
       factory()->NewVariableDeclaration(proxy, LET, scope_, pos);
   Declare(declaration, true, CHECK_OK);
   proxy->var()->set_initializer_position(pos);
 
   Token::Value init_op = Token::INIT_LET;
   Assignment* assignment = factory()->NewAssignment(init_op, proxy, value, pos);
   Statement* assignment_statement =
       factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition);
   if (names) names->Add(name, zone());
   return assignment_statement;
 }
 
 
 Block* Parser::ParseBlock(ZoneList<const AstRawString*>* labels, bool* ok) {
-  if (allow_harmony_scoping() && strict_mode() == STRICT) {
+  if (allow_harmony_scoping() && is_strict(language_mode())) {
     return ParseScopedBlock(labels, ok);
   }
 
   // Block ::
   //   '{' Statement* '}'
 
   // Note that a Block does not introduce a new execution scope!
   // (ECMA-262, 3rd, 12.2)
   //
   // Construct block expecting 16 statements.
@@ skipping 90 matching lines @@
   // bindings are created uninitialized by their declaration nodes and
   // need initialization. 'var' declared bindings are always initialized
   // immediately by their declaration nodes.
   bool needs_init = false;
   bool is_const = false;
   Token::Value init_op = Token::INIT_VAR;
   if (peek() == Token::VAR) {
     Consume(Token::VAR);
   } else if (peek() == Token::CONST) {
     Consume(Token::CONST);
-    switch (strict_mode()) {
-      case SLOPPY:
-        mode = CONST_LEGACY;
-        init_op = Token::INIT_CONST_LEGACY;
-        break;
-      case STRICT:
-        DCHECK(var_context != kStatement);
-        // In ES5 const is not allowed in strict mode.
-        if (!allow_harmony_scoping()) {
-          ReportMessage("strict_const");
-          *ok = false;
-          return NULL;
-        }
-        mode = CONST;
-        init_op = Token::INIT_CONST;
+    if (!is_strict(language_mode())) {
+      mode = CONST_LEGACY;
+      init_op = Token::INIT_CONST_LEGACY;
+    } else {
+      DCHECK(var_context != kStatement);
+      // In ES5 const is not allowed in strict mode.
+      if (!allow_harmony_scoping()) {
+        ReportMessage("strict_const");
+        *ok = false;
+        return NULL;
+      }
+      mode = CONST;
+      init_op = Token::INIT_CONST;
     }
     is_const = true;
     needs_init = true;
-  } else if (peek() == Token::LET && strict_mode() == STRICT) {
+  } else if (peek() == Token::LET && is_strict(language_mode())) {
     DCHECK(allow_harmony_scoping());
     Consume(Token::LET);
     DCHECK(var_context != kStatement);
     mode = LET;
     needs_init = true;
     init_op = Token::INIT_LET;
   } else {
     UNREACHABLE();  // by current callers
   }
 
@@ skipping 150 matching lines @@
 
         // Construct the call to Runtime_InitializeConstGlobal
         // and add it to the initialization statement block.
         // Note that the function does different things depending on
         // the number of arguments (1 or 2).
         initialize = factory()->NewCallRuntime(
             ast_value_factory()->initialize_const_global_string(),
             Runtime::FunctionForId(Runtime::kInitializeConstGlobal), arguments,
             pos);
       } else {
-        // Add strict mode.
+        // Add language mode.
         // We may want to pass singleton to avoid Literal allocations.
-        StrictMode strict_mode = initialization_scope->strict_mode();
-        arguments->Add(factory()->NewNumberLiteral(strict_mode, pos), zone());
+        LanguageMode language_mode = initialization_scope->language_mode();
+        arguments->Add(factory()->NewNumberLiteral(language_mode, pos), zone());
 
         // Be careful not to assign a value to the global variable if
         // we're in a with. The initialization value should not
         // necessarily be stored in the global object in that case,
         // which is why we need to generate a separate assignment node.
         if (value != NULL && !inside_with()) {
           arguments->Add(value, zone());
           value = NULL;  // zap the value to avoid the unnecessary assignment
           // Construct the call to Runtime_InitializeVarGlobal
           // and add it to the initialization statement block.
@@ skipping 288 matching lines @@
 
 
 Statement* Parser::ParseWithStatement(ZoneList<const AstRawString*>* labels,
                                       bool* ok) {
   // WithStatement ::
   //   'with' '(' Expression ')' Statement
 
   Expect(Token::WITH, CHECK_OK);
   int pos = position();
 
-  if (strict_mode() == STRICT) {
+  if (is_strict(language_mode())) {
     ReportMessage("strict_mode_with");
     *ok = false;
     return NULL;
   }
 
   Expect(Token::LPAREN, CHECK_OK);
   Expression* expr = ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
   scope_->DeclarationScope()->RecordWithStatement();
@@ skipping 549 matching lines @@
   Scope* saved_scope = scope_;
   Scope* for_scope = NewScope(scope_, BLOCK_SCOPE);
   scope_ = for_scope;
 
   Expect(Token::FOR, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
   for_scope->set_start_position(scanner()->location().beg_pos);
   bool is_let_identifier_expression = false;
   if (peek() != Token::SEMICOLON) {
     if (peek() == Token::VAR ||
-        (peek() == Token::CONST && strict_mode() == SLOPPY)) {
+        (peek() == Token::CONST && !is_strict(language_mode()))) {
       bool is_const = peek() == Token::CONST;
       const AstRawString* name = NULL;
       VariableDeclarationProperties decl_props = kHasNoInitializers;
       Block* variable_statement =
           ParseVariableDeclarations(kForStatement, &decl_props, NULL, &name,
                                     CHECK_OK);
       bool accept_OF = decl_props == kHasNoInitializers;
       ForEachStatement::VisitMode mode;
       int each_pos = position();
 
@@ skipping 18 matching lines @@
         scope_ = saved_scope;
         for_scope->set_end_position(scanner()->location().end_pos);
         for_scope = for_scope->FinalizeBlockScope();
         DCHECK(for_scope == NULL);
         // Parsed for-in loop w/ variable/const declaration.
         return result;
       } else {
         init = variable_statement;
       }
     } else if ((peek() == Token::LET || peek() == Token::CONST) &&
-               strict_mode() == STRICT) {
+               is_strict(language_mode())) {
       bool is_const = peek() == Token::CONST;
       const AstRawString* name = NULL;
       VariableDeclarationProperties decl_props = kHasNoInitializers;
       Block* variable_statement =
           ParseVariableDeclarations(kForStatement, &decl_props, &let_bindings,
                                     &name, CHECK_OK);
       bool accept_IN = name != NULL && decl_props != kHasInitializers;
       bool accept_OF = decl_props == kHasNoInitializers;
       ForEachStatement::VisitMode mode;
       int each_pos = position();
@@ skipping 86 matching lines @@
       }
     }
   }
 
   // Standard 'for' loop
   ForStatement* loop = factory()->NewForStatement(labels, stmt_pos);
   Target target(&this->target_stack_, loop);
 
   // Parsed initializer at this point.
   // Detect attempts at 'let' declarations in sloppy mode.
-  if (peek() == Token::IDENTIFIER && strict_mode() == SLOPPY &&
+  if (peek() == Token::IDENTIFIER && !is_strict(language_mode()) &&
       is_let_identifier_expression) {
     ReportMessage("sloppy_lexical", NULL);
     *ok = false;
     return NULL;
   }
   Expect(Token::SEMICOLON, CHECK_OK);
 
   // If there are let bindings, then condition and the next statement of the
   // for loop must be parsed in a new scope.
   Scope* inner_scope = NULL;
@@ skipping 234 matching lines @@
   //   in all normal cases, function declarations are fully hoisted to a
   //   declaration scope and compiled relative to that.
   // - (2) is the case iff the current declaration scope is still the original
   //   one relative to the deserialized scope chain. Otherwise we must be
   //   compiling a function in an inner declaration scope in the eval, e.g. a
   //   nested function, and hoisting works normally relative to that.
   Scope* declaration_scope = scope_->DeclarationScope();
   Scope* original_declaration_scope = original_scope_->DeclarationScope();
   Scope* scope =
       function_type == FunctionLiteral::DECLARATION &&
-      (!allow_harmony_scoping() || strict_mode() == SLOPPY) &&
-      (original_scope_ == original_declaration_scope ||
-       declaration_scope != original_declaration_scope)
+              (!allow_harmony_scoping() || !is_strict(language_mode())) &&
+              (original_scope_ == original_declaration_scope ||
+               declaration_scope != original_declaration_scope)
           ? NewScope(declaration_scope, FUNCTION_SCOPE)
           : NewScope(scope_, FUNCTION_SCOPE);
   ZoneList<Statement*>* body = NULL;
   int materialized_literal_count = -1;
   int expected_property_count = -1;
   int handler_count = 0;
   FunctionLiteral::ParameterFlag duplicate_parameters =
       FunctionLiteral::kNoDuplicateParameters;
   FunctionLiteral::IsParenthesizedFlag parenthesized = parenthesized_function_
       ? FunctionLiteral::kIsParenthesized
@@ skipping 51 matching lines @@
       }
       if (!reserved_loc.IsValid() && is_strict_reserved) {
         reserved_loc = scanner()->location();
       }
       if (!dupe_error_loc.IsValid() && scope_->IsDeclared(param_name)) {
         duplicate_parameters = FunctionLiteral::kHasDuplicateParameters;
         dupe_error_loc = scanner()->location();
       }
 
       Variable* var = scope_->DeclareParameter(param_name, VAR, is_rest);
-      if (scope->strict_mode() == SLOPPY) {
+      if (!is_strict(scope->language_mode())) {
         // TODO(sigurds) Mark every parameter as maybe assigned. This is a
         // conservative approximation necessary to account for parameters
         // that are assigned via the arguments array.
         var->set_maybe_assigned();
       }
 
       num_parameters++;
       if (num_parameters > Code::kMaxArguments) {
         ReportMessage("too_many_parameters");
         *ok = false;
@@ skipping 16 matching lines @@
 
     // If we have a named function expression, we add a local variable
     // declaration to the body of the function with the name of the
     // function and let it refer to the function itself (closure).
     // NOTE: We create a proxy and resolve it here so that in the
     // future we can change the AST to only refer to VariableProxies
     // instead of Variables and Proxis as is the case now.
     Variable* fvar = NULL;
     Token::Value fvar_init_op = Token::INIT_CONST_LEGACY;
     if (function_type == FunctionLiteral::NAMED_EXPRESSION) {
-      if (allow_harmony_scoping() && strict_mode() == STRICT) {
+      if (allow_harmony_scoping() && is_strict(language_mode())) {
         fvar_init_op = Token::INIT_CONST;
       }
       VariableMode fvar_mode =
-          allow_harmony_scoping() && strict_mode() == STRICT
-              ? CONST : CONST_LEGACY;
+          allow_harmony_scoping() && is_strict(language_mode()) ? CONST
+                                                                : CONST_LEGACY;
       DCHECK(function_name != NULL);
       fvar = new (zone())
           Variable(scope_, function_name, fvar_mode, true /* is valid LHS */,
                    Variable::NORMAL, kCreatedInitialized, kNotAssigned,
                    Interface::NewConst());
       VariableProxy* proxy = factory()->NewVariableProxy(fvar);
       VariableDeclaration* fvar_declaration = factory()->NewVariableDeclaration(
           proxy, fvar_mode, scope_, RelocInfo::kNoPosition);
       scope_->DeclareFunctionVar(fvar_declaration);
     }
@@ skipping 44 matching lines @@
                                     is_generator, CHECK_OK);
       materialized_literal_count = function_state.materialized_literal_count();
       expected_property_count = function_state.expected_property_count();
       handler_count = function_state.handler_count();
     }
 
     // Validate strict mode.
     // Concise methods use StrictFormalParameters.
     // Functions for which IsSimpleParameterList() returns false use
     // StrictFormalParameters.
-    if (strict_mode() == STRICT || IsConciseMethod(kind) || is_rest) {
+    if (is_strict(language_mode()) || IsConciseMethod(kind) || is_rest) {
       CheckStrictFunctionNameAndParameters(function_name,
                                            name_is_strict_reserved,
                                            function_name_location,
                                            eval_args_error_log,
                                            dupe_error_loc,
                                            reserved_loc,
                                            CHECK_OK);
     }
-    if (strict_mode() == STRICT) {
+    if (is_strict(language_mode())) {
       CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
                               CHECK_OK);
     }
-    if (allow_harmony_scoping() && strict_mode() == STRICT) {
+    if (allow_harmony_scoping() && is_strict(language_mode())) {
       CheckConflictingVarDeclarations(scope, CHECK_OK);
     }
   }
 
   FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
       function_name, ast_value_factory(), scope, body,
       materialized_literal_count, expected_property_count, handler_count,
       num_parameters, duplicate_parameters, function_type,
       FunctionLiteral::kIsFunction, parenthesized, kind, pos);
   function_literal->set_function_token_position(function_token_pos);
@@ skipping 22 matching lines @@
       scanner()->SeekForward(entry.end_pos() - 1);
 
       scope_->set_end_position(entry.end_pos());
       Expect(Token::RBRACE, ok);
       if (!*ok) {
         return;
       }
       total_preparse_skipped_ += scope_->end_position() - function_block_pos;
       *materialized_literal_count = entry.literal_count();
       *expected_property_count = entry.property_count();
-      scope_->SetStrictMode(entry.strict_mode());
+      scope_->SetLanguageMode(entry.language_mode());
       return;
     }
     cached_parse_data_->Reject();
   }
   // With no cached data, we partially parse the function, without building an
   // AST. This gathers the data needed to build a lazy function.
   SingletonLogger logger;
   PreParser::PreParseResult result =
       ParseLazyFunctionBodyWithPreParser(&logger);
   if (result == PreParser::kPreParseStackOverflow) {
@@ skipping 10 matching lines @@
     return;
   }
   scope_->set_end_position(logger.end());
   Expect(Token::RBRACE, ok);
   if (!*ok) {
     return;
   }
   total_preparse_skipped_ += scope_->end_position() - function_block_pos;
   *materialized_literal_count = logger.literals();
   *expected_property_count = logger.properties();
-  scope_->SetStrictMode(logger.strict_mode());
+  scope_->SetLanguageMode(logger.language_mode());
   if (produce_cached_parse_data()) {
     DCHECK(log_);
     // Position right after terminal '}'.
     int body_end = scanner()->location().end_pos;
     log_->LogFunction(function_block_pos, body_end, *materialized_literal_count,
-                      *expected_property_count, scope_->strict_mode());
+                      *expected_property_count, scope_->language_mode());
   }
 }
 
 
 ZoneList<Statement*>* Parser::ParseEagerFunctionBody(
     const AstRawString* function_name, int pos, Variable* fvar,
     Token::Value fvar_init_op, bool is_generator, bool* ok) {
   // Everything inside an eagerly parsed function will be parsed eagerly
   // (see comment above).
   ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
@@ skipping 74 matching lines @@
     reusable_preparser_->set_allow_harmony_object_literals(
         allow_harmony_object_literals());
     reusable_preparser_->set_allow_harmony_templates(allow_harmony_templates());
     reusable_preparser_->set_allow_harmony_sloppy(allow_harmony_sloppy());
     reusable_preparser_->set_allow_harmony_unicode(allow_harmony_unicode());
     reusable_preparser_->set_allow_harmony_computed_property_names(
         allow_harmony_computed_property_names());
     reusable_preparser_->set_allow_harmony_rest_params(
         allow_harmony_rest_params());
   }
-  PreParser::PreParseResult result =
-      reusable_preparser_->PreParseLazyFunction(strict_mode(),
-                                                is_generator(),
-                                                logger);
+  PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
+      language_mode(), is_generator(), logger);
   if (pre_parse_timer_ != NULL) {
     pre_parse_timer_->Stop();
   }
   return result;
 }
 
 
 ClassLiteral* Parser::ParseClassLiteral(const AstRawString* name,
                                         Scanner::Location class_name_location,
                                         bool name_is_strict_reserved, int pos,
                                         bool* ok) {
   // All parts of a ClassDeclaration and ClassExpression are strict code.
   if (name_is_strict_reserved) {
     ReportMessageAt(class_name_location, "unexpected_strict_reserved");
     *ok = false;
     return NULL;
   }
   if (IsEvalOrArguments(name)) {
     ReportMessageAt(class_name_location, "strict_eval_arguments");
     *ok = false;
     return NULL;
   }
 
   Scope* block_scope = NewScope(scope_, BLOCK_SCOPE);
   BlockState block_state(&scope_, block_scope);
-  scope_->SetStrictMode(STRICT);
+  scope_->SetLanguageMode(
+      static_cast<LanguageMode>(scope_->language_mode() | STRICT));
   scope_->SetScopeName(name);
 
   VariableProxy* proxy = NULL;
   if (name != NULL) {
     proxy = NewUnresolved(name, CONST, Interface::NewConst());
     Declaration* declaration =
         factory()->NewVariableDeclaration(proxy, CONST, block_scope, pos);
     Declare(declaration, true, CHECK_OK);
   }
 
@@ skipping 1342 matching lines @@
     } else {
       const uc16* data = reinterpret_cast<const uc16*>(raw_string->raw_data());
       running_hash = StringHasher::ComputeRunningHash(running_hash, data,
                                                       raw_string->length());
     }
   }
 
   return running_hash;
 }
 } }  // namespace v8::internal