Re-apply formal argument, arrow function parsing refactors

src/parser.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_PARSER_H_
 #define V8_PARSER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/compiler.h"  // TODO(titzer): remove this include dependency
@@ skipping 539 matching lines @@
     // Return types for traversing functions.
     typedef const AstRawString* Identifier;
     typedef v8::internal::Expression* Expression;
     typedef Yield* YieldExpression;
     typedef v8::internal::FunctionLiteral* FunctionLiteral;
     typedef v8::internal::ClassLiteral* ClassLiteral;
     typedef v8::internal::Literal* Literal;
     typedef ObjectLiteral::Property* ObjectLiteralProperty;
     typedef ZoneList<v8::internal::Expression*>* ExpressionList;
     typedef ZoneList<ObjectLiteral::Property*>* PropertyList;
+    typedef const v8::internal::AstRawString* FormalParameter;
+    typedef Scope FormalParameterScope;
     typedef ZoneList<v8::internal::Statement*>* StatementList;
 
     // For constructing objects returned by the traversing functions.
     typedef AstNodeFactory Factory;
   };
 
   explicit ParserTraits(Parser* parser) : parser_(parser) {}
 
   // Helper functions for recursive descent.
   bool IsEval(const AstRawString* identifier) const;
@@ skipping 117 matching lines @@
                        const AstRawString* arg,
                        ParseErrorType error_type = kSyntaxError);
 
   // "null" return type creators.
   static const AstRawString* EmptyIdentifier() {
     return NULL;
   }
   static Expression* EmptyExpression() {
     return NULL;
   }
-  static Expression* EmptyArrowParamList() { return NULL; }
   static Literal* EmptyLiteral() {
     return NULL;
   }
   static ObjectLiteralProperty* EmptyObjectLiteralProperty() { return NULL; }
   static FunctionLiteral* EmptyFunctionLiteral() { return NULL; }
 
   // Used in error return values.
   static ZoneList<Expression*>* NullExpressionList() {
     return NULL;
   }
+  static const AstRawString* EmptyFormalParameter() { return NULL; }
 
   // Non-NULL empty string.
   V8_INLINE const AstRawString* EmptyIdentifierString();
 
   // Odd-ball literal creators.
   Literal* GetLiteralTheHole(int position, AstNodeFactory* factory);
 
   // Producing data during the recursive descent.
   const AstRawString* GetSymbol(Scanner* scanner);
   const AstRawString* GetNextSymbol(Scanner* scanner);
@@ skipping 18 matching lines @@
   }
   ZoneList<ObjectLiteral::Property*>* NewPropertyList(int size, Zone* zone) {
     return new(zone) ZoneList<ObjectLiteral::Property*>(size, zone);
   }
   ZoneList<v8::internal::Statement*>* NewStatementList(int size, Zone* zone) {
     return new(zone) ZoneList<v8::internal::Statement*>(size, zone);
   }
   V8_INLINE Scope* NewScope(Scope* parent_scope, ScopeType scope_type,
                             FunctionKind kind = kNormalFunction);
 
-  // Utility functions
-  int DeclareArrowParametersFromExpression(Expression* expression, Scope* scope,
-                                           Scanner::Location* undefined_loc,
-                                           Scanner::Location* dupe_loc,
-                                           bool* ok);
+  bool DeclareFormalParameter(Scope* scope, const AstRawString* name,
+                              bool is_rest) {
+    bool was_declared = scope->IsDeclared(name);
+    Variable* var = scope->DeclareParameter(name, VAR, is_rest);

[marja, 2015/04/21 08:01:50]

As discussed offline: this does 2 Lookups; it's possible to refactor so that it
does only 1.

Probably that's worthwhile to try out, since it looks like we're on a critical
path for CodeLoad here.

+    if (is_sloppy(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();
+    }
+    return was_declared;
+  }
+
+  void DeclareArrowFunctionParameters(Scope* scope, Expression* expr,
+                                      const Scanner::Location& params_loc,
+                                      FormalParameterErrorLocations* error_locs,
+                                      bool* ok);
+  void ParseArrowFunctionFormalParameters(
+      Scope* scope, Expression* params, const Scanner::Location& params_loc,
+      FormalParameterErrorLocations* error_locs, bool* is_rest, bool* ok);
 
   // Temporary glue; these functions will move to ParserBase.
   Expression* ParseV8Intrinsic(bool* ok);
   FunctionLiteral* ParseFunctionLiteral(
       const AstRawString* name, Scanner::Location function_name_location,
       bool name_is_strict_reserved, FunctionKind kind,
       int function_token_position, FunctionLiteral::FunctionType type,
       FunctionLiteral::ArityRestriction arity_restriction, bool* ok);
   V8_INLINE void SkipLazyFunctionBody(const AstRawString* name,
                                       int* materialized_literal_count,
@@ skipping 277 matching lines @@
   Expression* SpreadCallNew(Expression* function,
                             ZoneList<v8::internal::Expression*>* args, int pos);
 
   Scanner scanner_;
   PreParser* reusable_preparser_;
   Scope* original_scope_;  // for ES5 function declarations in sloppy eval
   Target* target_stack_;  // for break, continue statements
   ScriptCompiler::CompileOptions compile_options_;
   ParseData* cached_parse_data_;
 
-  bool parsing_lazy_arrow_parameters_;  // for lazily parsed arrow functions.
-
   PendingCompilationErrorHandler pending_error_handler_;
 
   // Other information which will be stored in Parser and moved to Isolate after
   // parsing.
   int use_counts_[v8::Isolate::kUseCounterFeatureCount];
   int total_preparse_skipped_;
   HistogramTimer* pre_parse_timer_;
 
   bool parsing_on_main_thread_;
 };
@@ skipping 102 matching lines @@
 }
 
 
 Expression* ParserTraits::SpreadCallNew(
     Expression* function, ZoneList<v8::internal::Expression*>* args, int pos) {
   return parser_->SpreadCallNew(function, args, pos);
 }
 } }  // namespace v8::internal
 
 #endif  // V8_PARSER_H_