[parser] Only track parsing-mode (and possibly switch to the preparser) in the parser

src/parsing/parser-base.h

 // 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.
 
 #ifndef V8_PARSING_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
@@ skipping 180 matching lines @@
   const Impl* impl() const { return static_cast<const Impl*>(this); }
 
   ParserBase(Zone* zone, Scanner* scanner, uintptr_t stack_limit,
              v8::Extension* extension, AstValueFactory* ast_value_factory)
       : scope_state_(nullptr),
         function_state_(nullptr),
         extension_(extension),
         fni_(nullptr),
         ast_value_factory_(ast_value_factory),
         ast_node_factory_(ast_value_factory),
-        mode_(PARSE_EAGERLY),  // Lazy mode must be set explicitly.
         parsing_module_(false),
         stack_limit_(stack_limit),
         zone_(zone),
         classifier_(nullptr),
         scanner_(scanner),
         stack_overflow_(false),
         default_eager_compile_hint_(FunctionLiteral::kShouldLazyCompile),
         allow_lazy_(false),
         allow_natives_(false),
         allow_tailcalls_(false),
@@ skipping 36 matching lines @@
   Zone* zone() const { return zone_; }
 
  protected:
   friend class v8::internal::ExpressionClassifier<ParserTypes<Impl>>;
 
   enum AllowRestrictedIdentifiers {
     kAllowRestrictedIdentifiers,
     kDontAllowRestrictedIdentifiers
   };
 
-  enum Mode { PARSE_LAZILY, PARSE_EAGERLY };
-
   enum LazyParsingResult { kLazyParsingComplete, kLazyParsingAborted };
 
   enum VariableDeclarationContext {
     kStatementListItem,
     kStatement,
     kForStatement
   };
 
   enum class FunctionBodyType { kNormal, kSingleExpression };
 
@@ skipping 314 matching lines @@
           next_materialized_literal_index_;
       function_state_->expected_property_count_ = expected_property_count_;
     }
 
    private:
     FunctionState* function_state_;
     int next_materialized_literal_index_;
     int expected_property_count_;
   };
 
-  class ParsingModeScope BASE_EMBEDDED {
-   public:
-    ParsingModeScope(ParserBase* parser, Mode mode)
-        : parser_(parser),
-          old_mode_(parser->mode()) {
-      parser_->mode_ = mode;
-    }
-    ~ParsingModeScope() {
-      parser_->mode_ = old_mode_;
-    }
-
-   private:
-    ParserBase* parser_;
-    Mode old_mode_;
-  };
-
   struct DeclarationDescriptor {
     enum Kind { NORMAL, PARAMETER };
     Scope* scope;
     Scope* hoist_scope;
     VariableMode mode;
     int declaration_pos;
     int initialization_pos;
     Kind declaration_kind;
   };
 
@@ skipping 126 matching lines @@
   V8_INLINE DeclarationScope* GetClosureScope() const {
     return scope()->GetClosureScope();
   }
 
   Scanner* scanner() const { return scanner_; }
   AstValueFactory* ast_value_factory() const { return ast_value_factory_; }
   int position() const { return scanner_->location().beg_pos; }
   int peek_position() const { return scanner_->peek_location().beg_pos; }
   bool stack_overflow() const { return stack_overflow_; }
   void set_stack_overflow() { stack_overflow_ = true; }
-  Mode mode() const { return mode_; }
 
   INLINE(Token::Value peek()) {
     if (stack_overflow_) return Token::ILLEGAL;
     return scanner()->peek();
   }
 
   INLINE(Token::Value PeekAhead()) {
     if (stack_overflow_) return Token::ILLEGAL;
     return scanner()->PeekAhead();
   }
@@ skipping 666 matching lines @@
   }
 
   // Parser base's protected field members.
 
   ScopeState* scope_state_;        // Scope stack.
   FunctionState* function_state_;  // Function state stack.
   v8::Extension* extension_;
   FuncNameInferrer* fni_;
   AstValueFactory* ast_value_factory_;  // Not owned.
   typename Types::Factory ast_node_factory_;
-  Mode mode_;
   bool parsing_module_;
   uintptr_t stack_limit_;
 
   // Parser base's private field members.
 
  private:
   Zone* zone_;
   ExpressionClassifier* classifier_;
 
   Scanner* scanner_;
@@ skipping 2463 matching lines @@
     return impl()->EmptyExpression();
   }
 
   StatementListT body = impl()->NullStatementList();
   int materialized_literal_count = -1;
   int expected_property_count = -1;
 
   FunctionKind kind = formal_parameters.scope->function_kind();
   FunctionLiteral::EagerCompileHint eager_compile_hint =
       default_eager_compile_hint_;
-  bool can_preparse = mode() == PARSE_LAZILY &&
+  bool can_preparse = impl()->parse_lazily() &&
                       eager_compile_hint == FunctionLiteral::kShouldLazyCompile;
   // TODO(marja): consider lazy-parsing inner arrow functions too. is_this
   // handling in Scope::ResolveVariable needs to change.
   bool is_lazy_top_level_function =
       can_preparse && impl()->AllowsLazyParsingWithoutUnresolvedVariables();
   bool should_be_used_once_hint = false;
   {
     FunctionState function_state(&function_state_, &scope_state_,
                                  formal_parameters.scope);
 
@@ skipping 460 matching lines @@
         if (!scope()->HasSimpleParameters()) {
           // TC39 deemed "use strict" directives to be an error when occurring
           // in the body of a function with non-simple parameter list, on
           // 29/7/2015. https://goo.gl/ueA7Ln
           impl()->ReportMessageAt(
               token_loc, MessageTemplate::kIllegalLanguageModeDirective,
               "use strict");
           *ok = false;
           return kLazyParsingComplete;
         }
-        // Because declarations in strict eval code don't leak into the scope
-        // of the eval call, it is likely that functions declared in strict
-        // eval code will be used within the eval code, so lazy parsing is
-        // probably not a win.
-        if (scope()->is_eval_scope()) mode_ = PARSE_EAGERLY;
       } else if (impl()->IsUseAsmDirective(stat) &&
                  token_loc.end_pos - token_loc.beg_pos ==
                      sizeof("use asm") + 1) {
         // Directive "use asm".
         impl()->SetAsmModule();
       } else if (impl()->IsStringLiteral(stat)) {
         // Possibly an unknown directive.
         // Should not change mode, but will increment usage counters
         // as appropriate. Ditto usages below.
         RaiseLanguageMode(SLOPPY);
@@ skipping 1039 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H