(Pre)Parser: Move FunctionState, BlockState and Scope handling to ParserBase.

Notes:
- This removes Parser::FunctionState and PreParser::FunctionState and adds
ParserBase::FunctionState etc.
- Also the scope stacks and function state stacks are moved to ParserBase.
- PreParser::FunctionState didn't add and subtract
JSFunction::kLiteralsPrefixSize (unlike Parser::FunctionState). Since the
actual value of NextMaterializedLiteralIndex is not used in the Preparser,
this change is valid.
- Traits no longer need functions like is_classic_mode(), since now there is a
 unified way of getting the information from the FunctionState / Scope.

R=ulan@chromium.org
BUG=v8:3126
LOG=N

Review URL: https://codereview.chromium.org/135213007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19361 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/parser.cc

@@ -462,58 +462,6 @@ class TargetScope BASE_EMBEDDED {
 };
 
 
-// ----------------------------------------------------------------------------
-// FunctionState and BlockState together implement the parser's scope stack.
-// The parser's current scope is in scope_.  The BlockState and
-// FunctionState constructors push on the scope stack and the destructors
-// pop.  They are also used to hold the parser's per-function and per-block
-// state.
-
-class Parser::BlockState BASE_EMBEDDED {
- public:
-  BlockState(Scope** scope_stack, Scope* scope)
-      : scope_stack_(scope_stack),
-        outer_scope_(*scope_stack) {
-    *scope_stack = scope;
-  }
-
-  ~BlockState() { *scope_stack_ = outer_scope_; }
-
- private:
-  Scope** scope_stack_;
-  Scope* outer_scope_;
-};
-
-
-Parser::FunctionState::FunctionState(FunctionState** function_state_stack,
-                                     Scope** scope_stack, Scope* scope,
-                                     Zone* zone)
-    : next_materialized_literal_index_(JSFunction::kLiteralsPrefixSize),
-      next_handler_index_(0),
-      expected_property_count_(0),
-      generator_object_variable_(NULL),
-      function_state_stack_(function_state_stack),
-      outer_function_state_(*function_state_stack),
-      scope_stack_(scope_stack),
-      outer_scope_(*scope_stack),
-      isolate_(zone->isolate()),
-      saved_ast_node_id_(isolate_->ast_node_id()),
-      factory_(zone) {
-  *scope_stack_ = scope;
-  *function_state_stack = this;
-  isolate_->set_ast_node_id(BailoutId::FirstUsable().ToInt());
-}
-
-
-Parser::FunctionState::~FunctionState() {
-  *scope_stack_ = outer_scope_;
-  *function_state_stack_ = outer_function_state_;
-  if (outer_function_state_ != NULL) {
-    isolate_->set_ast_node_id(saved_ast_node_id_);
-  }
-}
-
-
 // ----------------------------------------------------------------------------
 // The CHECK_OK macro is a convenient macro to enforce error
 // handling for functions that may fail (by returning !*ok).
@@ -537,16 +485,6 @@ Parser::FunctionState::~FunctionState() {
 // ----------------------------------------------------------------------------
 // Implementation of Parser
 
-bool ParserTraits::is_classic_mode() const {
-  return parser_->scope_->is_classic_mode();
-}
-
-
-bool ParserTraits::is_generator() const {
-  return parser_->function_state_->is_generator();
-}
-
-
 bool ParserTraits::IsEvalOrArguments(Handle<String> identifier) const {
   return identifier.is_identical_to(
              parser_->isolate()->factory()->eval_string()) ||
@@ -555,11 +493,6 @@ bool ParserTraits::IsEvalOrArguments(Handle<String> identifier) const {
 }
 
 
-int ParserTraits::NextMaterializedLiteralIndex() {
-  return parser_->function_state_->NextMaterializedLiteralIndex();
-}
-
-
 void ParserTraits::ReportMessageAt(Scanner::Location source_location,
                                    const char* message,
                                    Vector<const char*> args) {
@@ -623,14 +556,6 @@ Handle<String> ParserTraits::NextLiteralString(PretenureFlag tenured) {
 }
 
 
-Expression* ParserTraits::NewRegExpLiteral(Handle<String> js_pattern,
-                                           Handle<String> js_flags,
-                                           int literal_index,
-                                           int pos) {
-  return parser_->factory()->NewRegExpLiteral(
-      js_pattern, js_flags, literal_index, pos);
-}
-
 Parser::Parser(CompilationInfo* info)
     : ParserBase<ParserTraits>(&scanner_,
                                info->isolate()->stack_guard()->real_climit(),
@@ -640,9 +565,7 @@ Parser::Parser(CompilationInfo* info)
       script_(info->script()),
       scanner_(isolate_->unicode_cache()),
       reusable_preparser_(NULL),
-      scope_(NULL),
       original_scope_(NULL),
-      function_state_(NULL),
       target_stack_(NULL),
       extension_(info->extension()),
       pre_parse_data_(NULL),
@@ -4066,8 +3989,7 @@ FunctionLiteral* Parser::ParseFunctionLiteral(
 
       // Calling a generator returns a generator object.  That object is stored
       // in a temporary variable, a definition that is used by "yield"
-      // expressions.  Presence of a variable for the generator object in the
-      // FunctionState indicates that this function is a generator.
+      // expressions. This also marks the FunctionState as a generator.
       Variable* temp = scope_->DeclarationScope()->NewTemporary(
           isolate()->factory()->dot_generator_object_string());
       function_state.set_generator_object_variable(temp);

src/parser.h

@@ -409,18 +409,41 @@ class SingletonLogger;
 
 class ParserTraits {
  public:
-  typedef Parser* ParserType;
-  // Return types for traversing functions.
-  typedef Handle<String> IdentifierType;
-  typedef Expression* ExpressionType;
+  struct Type {
+    typedef v8::internal::Parser* Parser;
+
+    // Types used by FunctionState and BlockState.
+    typedef v8::internal::Scope Scope;
+    typedef AstNodeFactory<AstConstructionVisitor> Factory;
+    typedef Variable GeneratorVariable;
+    typedef v8::internal::Zone Zone;
+
+    // Return types for traversing functions.
+    typedef Handle<String> Identifier;
+    typedef v8::internal::Expression* Expression;
+  };
 
   explicit ParserTraits(Parser* parser) : parser_(parser) {}
 
+  // Custom operations executed when FunctionStates are created and destructed.
+  template<typename FS>
+  static void SetUpFunctionState(FS* function_state, Zone* zone) {
+    Isolate* isolate = zone->isolate();
+    function_state->isolate_ = isolate;
+    function_state->saved_ast_node_id_ = isolate->ast_node_id();
+    isolate->set_ast_node_id(BailoutId::FirstUsable().ToInt());
+  }
+
+  template<typename FS>
+  static void TearDownFunctionState(FS* function_state) {
+    if (function_state->outer_function_state_ != NULL) {
+      function_state->isolate_->set_ast_node_id(
+          function_state->saved_ast_node_id_);
+    }
+  }
+
   // Helper functions for recursive descent.
-  bool is_classic_mode() const;
-  bool is_generator() const;
   bool IsEvalOrArguments(Handle<String> identifier) const;
-  int NextMaterializedLiteralIndex();
 
   // Reporting errors.
   void ReportMessageAt(Scanner::Location source_location,
@@ -432,20 +455,16 @@ class ParserTraits {
                        Vector<Handle<String> > args);
 
   // "null" return type creators.
-  static IdentifierType EmptyIdentifier() {
+  static Handle<String> EmptyIdentifier() {
     return Handle<String>();
   }
-  static ExpressionType EmptyExpression() {
+  static Expression* EmptyExpression() {
     return NULL;
   }
 
   // Producing data during the recursive descent.
-  IdentifierType GetSymbol();
-  IdentifierType NextLiteralString(PretenureFlag tenured);
-  ExpressionType NewRegExpLiteral(IdentifierType js_pattern,
-                                  IdentifierType js_flags,
-                                  int literal_index,
-                                  int pos);
+  Handle<String> GetSymbol();
+  Handle<String> NextLiteralString(PretenureFlag tenured);
 
  private:
   Parser* parser_;
@@ -494,68 +513,6 @@ class Parser : public ParserBase<ParserTraits> {
     kHasNoInitializers
   };
 
-  class BlockState;
-
-  class FunctionState BASE_EMBEDDED {
-   public:
-    FunctionState(FunctionState** function_state_stack,
-                  Scope** scope_stack, Scope* scope,
-                  Zone* zone);
-    ~FunctionState();
-
-    int NextMaterializedLiteralIndex() {
-      return next_materialized_literal_index_++;
-    }
-    int materialized_literal_count() {
-      return next_materialized_literal_index_ - JSFunction::kLiteralsPrefixSize;
-    }
-
-    int NextHandlerIndex() { return next_handler_index_++; }
-    int handler_count() { return next_handler_index_; }
-
-    void AddProperty() { expected_property_count_++; }
-    int expected_property_count() { return expected_property_count_; }
-
-    void set_generator_object_variable(Variable *variable) {
-      ASSERT(variable != NULL);
-      ASSERT(!is_generator());
-      generator_object_variable_ = variable;
-    }
-    Variable* generator_object_variable() const {
-      return generator_object_variable_;
-    }
-    bool is_generator() const {
-      return generator_object_variable_ != NULL;
-    }
-
-    AstNodeFactory<AstConstructionVisitor>* factory() { return &factory_; }
-
-   private:
-    // Used to assign an index to each literal that needs materialization in
-    // the function.  Includes regexp literals, and boilerplate for object and
-    // array literals.
-    int next_materialized_literal_index_;
-
-    // Used to assign a per-function index to try and catch handlers.
-    int next_handler_index_;
-
-    // Properties count estimation.
-    int expected_property_count_;
-
-    // For generators, the variable that holds the generator object.  This
-    // variable is used by yield expressions and return statements.  NULL
-    // indicates that this function is not a generator.
-    Variable* generator_object_variable_;
-
-    FunctionState** function_state_stack_;
-    FunctionState* outer_function_state_;
-    Scope** scope_stack_;
-    Scope* outer_scope_;
-    Isolate* isolate_;
-    int saved_ast_node_id_;
-    AstNodeFactory<AstConstructionVisitor> factory_;
-  };
-
   class ParsingModeScope BASE_EMBEDDED {
    public:
     ParsingModeScope(Parser* parser, Mode mode)
@@ -770,19 +727,13 @@ class Parser : public ParserBase<ParserTraits> {
   PreParser::PreParseResult LazyParseFunctionLiteral(
        SingletonLogger* logger);
 
-  AstNodeFactory<AstConstructionVisitor>* factory() {
-    return function_state_->factory();
-  }
-
   Isolate* isolate_;
   ZoneList<Handle<String> > symbol_cache_;
 
   Handle<Script> script_;
   Scanner scanner_;
   PreParser* reusable_preparser_;
-  Scope* scope_;  // Scope stack.
   Scope* original_scope_;  // for ES5 function declarations in sloppy eval
-  FunctionState* function_state_;  // Function state stack.
   Target* target_stack_;  // for break, continue statements
   v8::Extension* extension_;
   ScriptDataImpl* pre_parse_data_;

src/preparser.cc

@@ -55,21 +55,6 @@ int isfinite(double value);
 namespace v8 {
 namespace internal {
 
-bool PreParserTraits::is_classic_mode() const {
-  return pre_parser_->scope_->language_mode() == CLASSIC_MODE;
-}
-
-
-bool PreParserTraits::is_generator() const {
-  return pre_parser_->function_state_->is_generator();
-}
-
-
-int PreParserTraits::NextMaterializedLiteralIndex() {
-  return pre_parser_->function_state_->NextMaterializedLiteralIndex();
-}
-
-
 void PreParserTraits::ReportMessageAt(Scanner::Location location,
                                       const char* message,
                                       Vector<const char*> args) {
@@ -126,10 +111,12 @@ PreParser::PreParseResult PreParser::PreParseLazyFunction(
     LanguageMode mode, bool is_generator, ParserRecorder* log) {
   log_ = log;
   // Lazy functions always have trivial outer scopes (no with/catch scopes).
-  FunctionState top_scope(&function_state_, &scope_, GLOBAL_SCOPE);
+  PreParserScope top_scope(scope_, GLOBAL_SCOPE);
+  FunctionState top_state(&function_state_, &scope_, &top_scope);
   scope_->SetLanguageMode(mode);
-  FunctionState function_scope(&function_state_, &scope_, FUNCTION_SCOPE);
-  function_scope.set_is_generator(is_generator);
+  PreParserScope function_scope(scope_, FUNCTION_SCOPE);
+  FunctionState function_state(&function_state_, &scope_, &function_scope);
+  function_state.set_is_generator(is_generator);
   ASSERT_EQ(Token::LBRACE, scanner()->current_token());
   bool ok = true;
   int start_position = peek_position();
@@ -602,7 +589,8 @@ PreParser::Statement PreParser::ParseWithStatement(bool* ok) {
   ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
-  BlockState block_state(&scope_, WITH_SCOPE);
+  PreParserScope with_scope(scope_, WITH_SCOPE);
+  BlockState block_state(&scope_, &with_scope);
   ParseStatement(CHECK_OK);
   return Statement::Default();
 }
@@ -776,7 +764,8 @@ PreParser::Statement PreParser::ParseTryStatement(bool* ok) {
     ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
     Expect(Token::RPAREN, CHECK_OK);
     {
-      BlockState block_state(&scope_, WITH_SCOPE);
+      PreParserScope with_scope(scope_, WITH_SCOPE);
+      BlockState block_state(&scope_, &with_scope);
       ParseBlock(CHECK_OK);
     }
     tok = peek();
@@ -1341,8 +1330,9 @@ PreParser::Expression PreParser::ParseFunctionLiteral(
   // Parse function body.
   ScopeType outer_scope_type = scope_->type();
   bool inside_with = scope_->inside_with();
-  FunctionState function_scope(&function_state_, &scope_, FUNCTION_SCOPE);
-  function_scope.set_is_generator(is_generator);
+  PreParserScope function_scope(scope_, FUNCTION_SCOPE);
+  FunctionState function_state(&function_state_, &scope_, &function_scope);
+  function_state.set_is_generator(is_generator);
   //  FormalParameterList ::
   //    '(' (Identifier)*[','] ')'
   Expect(Token::LPAREN, CHECK_OK);
@@ -1452,7 +1442,7 @@ void PreParser::ParseLazyFunctionLiteralBody(bool* ok) {
   int body_end = scanner()->peek_location().end_pos;
   log_->LogFunction(body_start, body_end,
                     function_state_->materialized_literal_count(),
-                    function_state_->expected_properties(),
+                    function_state_->expected_property_count(),
                     scope_->language_mode());
 }