[es6] implement destructuring assignment [clean diff]

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 1009 matching lines @@
     Scanner::Location bindings_loc;
   };
 
   class PatternRewriter : private AstVisitor {
    public:
     static void DeclareAndInitializeVariables(
         Block* block, const DeclarationDescriptor* declaration_descriptor,
         const DeclarationParsingResult::Declaration* declaration,
         ZoneList<const AstRawString*>* names, bool* ok);
 
+    static Variable* RewriteDestructuringAssignment(Parser* parser,
+                                                    Block* block,
+                                                    Expression* pattern,
+                                                    Expression* value,
+                                                    Variable* result, bool* ok);
+
     void set_initializer_position(int pos) { initializer_position_ = pos; }
 
    private:
     PatternRewriter() {}
 
 #define DECLARE_VISIT(type) void Visit##type(v8::internal::type* node) override;
     // Visiting functions for AST nodes make this an AstVisitor.
     AST_NODE_LIST(DECLARE_VISIT)
 #undef DECLARE_VISIT
     virtual void Visit(AstNode* node) override;
 
+    enum PatternContext { BINDING = 0, INITIALIZER, ASSIGNMENT };
+
+    PatternContext context() const { return context_; }
+    void set_context(PatternContext ctx) { context_ = ctx; }
+
     void RecurseIntoSubpattern(AstNode* pattern, Expression* value) {
       Expression* old_value = current_value_;
       current_value_ = value;
       pattern->Accept(this);
       current_value_ = old_value;
     }
 
     Variable* CreateTempVar(Expression* value = nullptr);
 
-    AstNodeFactory* factory() const { return descriptor_->parser->factory(); }
+    AstNodeFactory* factory() const { return parser_->factory(); }
+    Parser* parser() const { return parser_; }
+    Scope* parser_scope() const { return parser_->scope_; }
     AstValueFactory* ast_value_factory() const {
-      return descriptor_->parser->ast_value_factory();
+      return parser_->ast_value_factory();
     }
-    bool inside_with() const { return descriptor_->parser->inside_with(); }
-    Zone* zone() const { return descriptor_->parser->zone(); }
+    bool inside_with() const { return parser_->inside_with(); }
+    Zone* zone() const { return parser_->zone(); }
 
+    Parser* parser_;
+    PatternContext context_;
     Expression* pattern_;
     int initializer_position_;
     Block* block_;
     const DeclarationDescriptor* descriptor_;
     ZoneList<const AstRawString*>* names_;
     Expression* current_value_;
     bool* ok_;
+    Variable* rhs_;
   };
 
 
   void ParseVariableDeclarations(VariableDeclarationContext var_context,
                                  DeclarationParsingResult* parsing_result,
                                  bool* ok);
   Statement* ParseExpressionOrLabelledStatement(
       ZoneList<const AstRawString*>* labels, bool* ok);
   IfStatement* ParseIfStatement(ZoneList<const AstRawString*>* labels,
                                 bool* ok);
@@ skipping 31 matching lines @@
                                   Expression* subject,
                                   Statement* body);
   Statement* DesugarLexicalBindingsInForStatement(
       Scope* inner_scope, bool is_const, ZoneList<const AstRawString*>* names,
       ForStatement* loop, Statement* init, Expression* cond, Statement* next,
       Statement* body, bool* ok);
 
   void RewriteDoExpression(Expression* expr, bool* ok);
 
   Expression* DesugarDestructuringAssignment(Expression* expr);
+  Expression* DesugarDestructuringAssignmentInternal(Expression* expr,
+                                                     Variable** result);
 
   FunctionLiteral* ParseFunctionLiteral(
       const AstRawString* name, Scanner::Location function_name_location,
       FunctionNameValidity function_name_validity, FunctionKind kind,
       int function_token_position, FunctionLiteral::FunctionType type,
       FunctionLiteral::ArityRestriction arity_restriction,
       LanguageMode language_mode, bool* ok);
 
 
   ClassLiteral* ParseClassLiteral(const AstRawString* name,
@@ skipping 272 matching lines @@
 inline Expression* ParserTraits::RewriteDestructuringAssignment(
     Expression* expr) {
   return parser_->DesugarDestructuringAssignment(expr);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSER_H_