[esnext] prototype runtime implementation for async functions

src/parsing/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_PARSING_PARSER_H_
 #define V8_PARSING_PARSER_H_
 
 #include "src/allocation.h"
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
@@ skipping 511 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 void AddParameterInitializationBlock(
       const ParserFormalParameters& parameters,
-      ZoneList<v8::internal::Statement*>* body, bool* ok);
+      ZoneList<v8::internal::Statement*>* body, bool is_async, bool* ok);
+
+  void ParseAsyncArrowSingleExpressionBody(
+      ZoneList<Statement*>* body, bool accept_IN,
+      Type::ExpressionClassifier* classifier, int pos, bool* ok);
 
   V8_INLINE Scope* NewScope(Scope* parent_scope, ScopeType scope_type,
                             FunctionKind kind = kNormalFunction);
 
   V8_INLINE void AddFormalParameter(ParserFormalParameters* parameters,
                                     Expression* pattern,
                                     Expression* initializer,
                                     int initializer_end_position, bool is_rest);
   V8_INLINE void DeclareFormalParameter(
       Scope* scope, const ParserFormalParameters::Parameter& parameter,
@@ skipping 415 matching lines @@
                                   Expression* subject, Statement* body,
                                   int each_keyword_pos);
   void InitializeForOfStatement(ForOfStatement* stmt, Expression* each,
                                 Expression* iterable, Statement* body,
                                 int next_result_pos = RelocInfo::kNoPosition);
   Statement* DesugarLexicalBindingsInForStatement(
       Scope* inner_scope, VariableMode mode,
       ZoneList<const AstRawString*>* names, ForStatement* loop, Statement* init,
       Expression* cond, Statement* next, Statement* body, bool* ok);
 
+  void DesugarAsyncFunctionBody(const AstRawString* function_name, Scope* scope,
+                                ZoneList<Statement*>* body,
+                                Type::ExpressionClassifier* classifier,
+                                FunctionKind kind, FunctionBody type,
+                                bool accept_IN, int pos, bool* ok);
+
   void RewriteDoExpression(Expression* expr, bool* ok);
 
   FunctionLiteral* ParseFunctionLiteral(
       const AstRawString* name, Scanner::Location function_name_location,
       FunctionNameValidity function_name_validity, FunctionKind kind,
       int function_token_position, FunctionLiteral::FunctionType type,
       LanguageMode language_mode, bool* ok);
 
   ClassLiteral* ParseClassLiteral(ExpressionClassifier* classifier,
                                   const AstRawString* name,
@@ skipping 50 matching lines @@
   // In this case, it'll reset the scanner using the bookmark.
   void SkipLazyFunctionBody(int* materialized_literal_count,
                             int* expected_property_count, bool* ok,
                             Scanner::BookmarkScope* bookmark = nullptr);
 
   PreParser::PreParseResult ParseLazyFunctionBodyWithPreParser(
       SingletonLogger* logger, Scanner::BookmarkScope* bookmark = nullptr);
 
   Block* BuildParameterInitializationBlock(
       const ParserFormalParameters& parameters, bool* ok);
+  Block* BuildRejectPromiseOnException(Block* block);
 
   // Consumes the ending }.
   ZoneList<Statement*>* ParseEagerFunctionBody(
       const AstRawString* function_name, int pos,
       const ParserFormalParameters& parameters, FunctionKind kind,
       FunctionLiteral::FunctionType function_type, bool* ok);
 
   void ThrowPendingError(Isolate* isolate, Handle<Script> script);
 
   TemplateLiteralState OpenTemplateLiteral(int pos);
@@ skipping 24 matching lines @@
                                                     Expression* right, int pos);
 
   friend class NonPatternRewriter;
   V8_INLINE Expression* RewriteSpreads(ArrayLiteral* lit);
 
   V8_INLINE void RewriteNonPattern(ExpressionClassifier* classifier, bool* ok);
 
   friend class InitializerRewriter;
   void RewriteParameterInitializer(Expression* expr, Scope* scope);
 
+  Expression* EmitCreateJSGeneratorObject(int pos);
+  Expression* EmitPromiseResolve(Expression* value, int pos);
+  Expression* EmitPromiseReject(Expression* value, 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_;
 
   PendingCompilationErrorHandler pending_error_handler_;
 
   // Other information which will be stored in Parser and moved to Isolate after
@@ skipping 149 matching lines @@
         parser_->scanner()->location());
   }
   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();
   }
 }
 
-

[Dan Ehrenberg, 2016/05/04 22:52:36]

Nit: no need to delete the line

 void ParserTraits::AddParameterInitializationBlock(
     const ParserFormalParameters& parameters,
-    ZoneList<v8::internal::Statement*>* body, bool* ok) {
+    ZoneList<v8::internal::Statement*>* body, bool is_async, bool* ok) {
   if (!parameters.is_simple) {
     auto* init_block =
         parser_->BuildParameterInitializationBlock(parameters, ok);
     if (!*ok) return;
+
+    if (is_async) {
+      init_block = parser_->BuildRejectPromiseOnException(init_block);
+    }
+
     if (init_block != nullptr) {
       body->Add(init_block, parser_->zone());
     }
   }
 }
 
 Expression* ParserTraits::ParseAsyncFunctionExpression(bool* ok) {
   return parser_->ParseAsyncFunctionExpression(ok);
 }
 
 DoExpression* ParserTraits::ParseDoExpression(bool* ok) {
   return parser_->ParseDoExpression(ok);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_H_