[es7] implement |do| expressions proposal

src/parser.cc

 // 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.
 
 #include "src/parser.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/ast-literal-reindexer.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
 #include "src/bootstrapper.h"
 #include "src/char-predicates-inl.h"
 #include "src/codegen.h"
 #include "src/compiler.h"
 #include "src/messages.h"
 #include "src/preparser.h"
+#include "src/rewriter.h"
 #include "src/runtime/runtime.h"
 #include "src/scanner-character-streams.h"
 #include "src/scopeinfo.h"
 #include "src/string-stream.h"
 
 namespace v8 {
 namespace internal {
 
 ScriptData::ScriptData(const byte* data, int length)
     : owns_data_(false), rejected_(false), data_(data), length_(length) {
@@ skipping 889 matching lines @@
   set_allow_harmony_sloppy_function(FLAG_harmony_sloppy_function);
   set_allow_harmony_sloppy_let(FLAG_harmony_sloppy_let);
   set_allow_harmony_rest_parameters(FLAG_harmony_rest_parameters);
   set_allow_harmony_default_parameters(FLAG_harmony_default_parameters);
   set_allow_harmony_spread_calls(FLAG_harmony_spread_calls);
   set_allow_harmony_destructuring(FLAG_harmony_destructuring);
   set_allow_harmony_spread_arrays(FLAG_harmony_spread_arrays);
   set_allow_harmony_new_target(FLAG_harmony_new_target);
   set_allow_strong_mode(FLAG_strong_mode);
   set_allow_legacy_const(FLAG_legacy_const);
+  set_allow_harmony_do_expressions(FLAG_harmony_do_expressions);
   for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
        ++feature) {
     use_counts_[feature] = 0;
   }
   if (info->ast_value_factory() == NULL) {
     // info takes ownership of AstValueFactory.
     info->set_ast_value_factory(new AstValueFactory(zone(), info->hash_seed()));
     info->set_ast_value_factory_owned();
     ast_value_factory_ = info->ast_value_factory();
   }
@@ skipping 3083 matching lines @@
     DCHECK(parser_->allow_harmony_default_parameters());
     DCHECK(!assignment->is_compound());
     initializer = assignment->value();
     expr = assignment->target();
   }
 
   AddFormalParameter(parameters, expr, initializer, is_rest);
 }
 
 
+DoExpression* Parser::ParseDoExpression(bool* ok) {
+  // AssignmentExpression ::
+  //     do '{' StatementList '}'
+  int pos = peek_position();
+
+  Expect(Token::DO, CHECK_OK);
+  Variable* result =
+      scope_->NewTemporary(ast_value_factory()->dot_result_string());
+  Block* block = ParseScopedBlock(nullptr, CHECK_OK);
+  DoExpression* expr = factory()->NewDoExpression(block, result, pos);
+  if (!Rewriter::Rewrite(this, expr, ast_value_factory())) {
+    *ok = false;
+    return nullptr;
+  }
+  return expr;
+}
+
+
 void ParserTraits::ParseArrowFunctionFormalParameterList(
     ParserFormalParameters* parameters, Expression* expr,
     const Scanner::Location& params_loc,
     Scanner::Location* duplicate_loc, bool* ok) {
   if (expr->IsEmptyParentheses()) return;
 
   ParseArrowFunctionFormalParameters(parameters, expr, params_loc, ok);
   if (!*ok) return;
 
   ExpressionClassifier classifier;
@@ skipping 719 matching lines @@
     SET_ALLOW(natives);
     SET_ALLOW(harmony_sloppy);
     SET_ALLOW(harmony_sloppy_let);
     SET_ALLOW(harmony_rest_parameters);
     SET_ALLOW(harmony_default_parameters);
     SET_ALLOW(harmony_spread_calls);
     SET_ALLOW(harmony_destructuring);
     SET_ALLOW(harmony_spread_arrays);
     SET_ALLOW(harmony_new_target);
     SET_ALLOW(strong_mode);
+    SET_ALLOW(harmony_do_expressions);
 #undef SET_ALLOW
   }
   PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
       language_mode(), function_state_->kind(), scope_->has_simple_parameters(),
       logger, bookmark);
   if (pre_parse_timer_ != NULL) {
     pre_parse_timer_->Stop();
   }
   return result;
 }
@@ skipping 1558 matching lines @@
 
 Expression* Parser::SpreadCallNew(Expression* function,
                                   ZoneList<v8::internal::Expression*>* args,
                                   int pos) {
   args->InsertAt(0, function, zone());
 
   return factory()->NewCallRuntime(Context::REFLECT_CONSTRUCT_INDEX, args, pos);
 }
 }  // namespace internal
 }  // namespace v8