Teach Scopes whether they will end up being lazily compiled or not

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 182 matching lines @@
         allow_lazy_(false),
         allow_natives_(false),
         allow_tailcalls_(false),
         allow_harmony_restrictive_declarations_(false),
         allow_harmony_do_expressions_(false),
         allow_harmony_for_in_(false),
         allow_harmony_function_sent_(false),
         allow_harmony_async_await_(false),
         allow_harmony_restrictive_generators_(false),
         allow_harmony_trailing_commas_(false),
-        allow_harmony_class_fields_(false) {}
+        allow_harmony_class_fields_(false),
+        will_serialize_(false),
+        serializer_enabled_(false),
+        is_debug_(false) {}
 
 #define ALLOW_ACCESSORS(name)                           \
   bool allow_##name() const { return allow_##name##_; } \
   void set_allow_##name(bool allow) { allow_##name##_ = allow; }
 
   ALLOW_ACCESSORS(lazy);
   ALLOW_ACCESSORS(natives);
   ALLOW_ACCESSORS(tailcalls);
   ALLOW_ACCESSORS(harmony_restrictive_declarations);
   ALLOW_ACCESSORS(harmony_do_expressions);
   ALLOW_ACCESSORS(harmony_for_in);
   ALLOW_ACCESSORS(harmony_function_sent);
   ALLOW_ACCESSORS(harmony_async_await);
   ALLOW_ACCESSORS(harmony_restrictive_generators);
   ALLOW_ACCESSORS(harmony_trailing_commas);
   ALLOW_ACCESSORS(harmony_class_fields);
 
 #undef ALLOW_ACCESSORS
 
   uintptr_t stack_limit() const { return stack_limit_; }
 
   void set_stack_limit(uintptr_t stack_limit) { stack_limit_ = stack_limit; }
 
+  bool will_serialize() const { return will_serialize_; }
+  void set_will_serialize(bool will_serialize) {
+    will_serialize_ = will_serialize;
+  }
+  bool serializer_enabled() const { return serializer_enabled_; }
+  void set_serializer_enabled(bool serializer_enabled) {
+    serializer_enabled_ = serializer_enabled;
+  }
+  bool is_debug() const { return is_debug_; }
+  void set_is_debug(bool is_debug) { is_debug_ = is_debug; }
+
   Zone* zone() const { return zone_; }
 
  protected:
   friend class v8::internal::ExpressionClassifier<ParserTypes<Impl>>;
 
-  // clang-format off

[jochen (gone - plz use gerrit), 2016/10/06 11:30:15]

we shouldn't randomly disable clang-format, but stick to the coding style

   enum AllowRestrictedIdentifiers {
     kAllowRestrictedIdentifiers,
     kDontAllowRestrictedIdentifiers
   };
 
-  enum Mode {
-    PARSE_LAZILY,
-    PARSE_EAGERLY
-  };
+  enum Mode { PARSE_LAZILY, PARSE_EAGERLY };
 
-  enum LazyParsingResult {
-    kLazyParsingComplete,
-    kLazyParsingAborted
-  };
+  enum LazyParsingResult { kLazyParsingComplete, kLazyParsingAborted };
 
   enum VariableDeclarationContext {
     kStatementListItem,
     kStatement,
     kForStatement
   };
 
-  enum class FunctionBodyType {
-    kNormal,
-    kSingleExpression
-  };
-  // clang-format on
+  enum class FunctionBodyType { kNormal, kSingleExpression };
 
   class Checkpoint;
   class ClassLiteralChecker;
   class ObjectLiteralChecker;
 
   // ---------------------------------------------------------------------------
   // ScopeState and its subclasses implement the parser's scope stack.
   // ScopeState keeps track of the current scope, and the outer ScopeState. The
   // parser's scope_state_ points to the top ScopeState. ScopeState's
   // constructor push on the scope stack and the destructors pop. BlockState and
@@ skipping 1180 matching lines @@
   bool allow_tailcalls_;
   bool allow_harmony_restrictive_declarations_;
   bool allow_harmony_do_expressions_;
   bool allow_harmony_for_in_;
   bool allow_harmony_function_sent_;
   bool allow_harmony_async_await_;
   bool allow_harmony_restrictive_generators_;
   bool allow_harmony_trailing_commas_;
   bool allow_harmony_class_fields_;
 
+  bool will_serialize_;
+  bool serializer_enabled_;

[marja, 2016/10/06 11:53:06]

Seems unnecessary to need these bools in ParserBase.

They don't change, and they only affect the laziness decision, so I think it
would be enough to store one boolean which is set in the ctor.

Actually, we already have allow_lazy so why not use that? allow_lazy is already
a combination of various things which might disable laziness, and these are just
more of those things.

[jochen (gone - plz use gerrit), 2016/10/06 15:05:04]

allow_lazy is for native scripts for example - we need to parse them to find all
native functions. However, we still can compile lazily. Anyways, moving those
variables to parser works

+  bool is_debug_;
+
   friend class DiscardableZoneScope;
 };
 
 template <typename Impl>
 ParserBase<Impl>::FunctionState::FunctionState(
     FunctionState** function_state_stack, ScopeState** scope_stack,
     DeclarationScope* scope)
     : ScopeState(scope_stack, scope),
       next_materialized_literal_index_(0),
       expected_property_count_(0),
@@ skipping 815 matching lines @@
   typename Types::StatementList body = impl()->NewStatementList(1);
   body->Add(factory()->NewReturnStatement(value, kNoSourcePosition), zone());
   FunctionLiteralT function_literal = factory()->NewFunctionLiteral(
       impl()->EmptyIdentifierString(), initializer_scope, body,
       initializer_state.materialized_literal_count(),
       initializer_state.expected_property_count(), 0,
       FunctionLiteral::kNoDuplicateParameters,
       FunctionLiteral::kAnonymousExpression,
       FunctionLiteral::kShouldLazyCompile, initializer_scope->start_position());
   function_literal->set_is_class_field_initializer(true);
+  if (impl()->ShouldCompileLazily(function_literal)) {
+    initializer_scope->SetShouldCompileLazily(true);
+  }
   return function_literal;
 }
 
 template <typename Impl>
 typename ParserBase<Impl>::ObjectLiteralPropertyT
 ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
                                                 bool* is_computed_name,
                                                 bool* ok) {
   bool is_get = false;
   bool is_set = false;
@@ skipping 1732 matching lines @@
       formal_parameters.scope->start_position());
 
   function_literal->set_function_token_position(
       formal_parameters.scope->start_position());
   if (should_be_used_once_hint) {
     function_literal->set_should_be_used_once_hint();
   }
 
   impl()->AddFunctionForNameInference(function_literal);
 
+  if (impl()->ShouldCompileLazily(function_literal)) {
+    formal_parameters.scope->SetShouldCompileLazily(true);
+  }
+
   return function_literal;
 }
 
 template <typename Impl>
 typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
     IdentifierT name, Scanner::Location class_name_location,
     bool name_is_strict_reserved, int class_token_pos, bool* ok) {
   // All parts of a ClassDeclaration and ClassExpression are strict code.
   if (name_is_strict_reserved) {
     impl()->ReportMessageAt(class_name_location,
@@ skipping 630 matching lines @@
 template <typename Impl>
 typename ParserBase<Impl>::StatementT
 ParserBase<Impl>::ParseExpressionOrLabelledStatement(
     ZoneList<const AstRawString*>* labels,
     AllowLabelledFunctionStatement allow_function, bool* ok) {
   // ExpressionStatement | LabelledStatement ::
   //   Expression ';'
   //   Identifier ':' Statement
   //
   // ExpressionStatement[Yield] :
-  //   [lookahead ∉ {{, function, class, let [}] Expression[In, ?Yield] ;
+  //   [lookahead notin {{, function, class, let [}] Expression[In, ?Yield] ;

[jochen (gone - plz use gerrit), 2016/10/06 11:30:14]

clang-format.py can't deal with this character..

 
   int pos = peek_position();
 
   switch (peek()) {
     case Token::FUNCTION:
     case Token::LBRACE:
       UNREACHABLE();  // Always handled by the callers.
     case Token::CLASS:
       ReportUnexpectedToken(Next());
       *ok = false;
@@ skipping 748 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H