[es6] implement spread calls

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/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
@@ skipping 797 matching lines @@
   set_allow_harmony_arrow_functions(FLAG_harmony_arrow_functions);
   set_allow_harmony_numeric_literals(FLAG_harmony_numeric_literals);
   set_allow_harmony_classes(FLAG_harmony_classes);
   set_allow_harmony_object_literals(FLAG_harmony_object_literals);
   set_allow_harmony_templates(FLAG_harmony_templates);
   set_allow_harmony_sloppy(FLAG_harmony_sloppy);
   set_allow_harmony_unicode(FLAG_harmony_unicode);
   set_allow_harmony_computed_property_names(
       FLAG_harmony_computed_property_names);
   set_allow_harmony_rest_params(FLAG_harmony_rest_parameters);
+  set_allow_harmony_spreadcalls(FLAG_harmony_spreadcalls);
   set_allow_strong_mode(FLAG_strong_mode);
   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->SetAstValueFactory(new AstValueFactory(zone(), hash_seed));
     ast_value_factory_ = info->ast_value_factory();
   }
@@ skipping 3208 matching lines @@
     reusable_preparser_->set_allow_harmony_classes(allow_harmony_classes());
     reusable_preparser_->set_allow_harmony_object_literals(
         allow_harmony_object_literals());
     reusable_preparser_->set_allow_harmony_templates(allow_harmony_templates());
     reusable_preparser_->set_allow_harmony_sloppy(allow_harmony_sloppy());
     reusable_preparser_->set_allow_harmony_unicode(allow_harmony_unicode());
     reusable_preparser_->set_allow_harmony_computed_property_names(
         allow_harmony_computed_property_names());
     reusable_preparser_->set_allow_harmony_rest_params(
         allow_harmony_rest_params());
+    reusable_preparser_->set_allow_harmony_spreadcalls(
+        allow_harmony_spreadcalls());
     reusable_preparser_->set_allow_strong_mode(allow_strong_mode());
   }
   PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
       language_mode(), function_state_->kind(), logger);
   if (pre_parse_timer_ != NULL) {
     pre_parse_timer_->Stop();
   }
   return result;
 }
 
@@ skipping 91 matching lines @@
 
 
 Expression* Parser::ParseV8Intrinsic(bool* ok) {
   // CallRuntime ::
   //   '%' Identifier Arguments
 
   int pos = peek_position();
   Expect(Token::MOD, CHECK_OK);
   // Allow "eval" or "arguments" for backward compatibility.
   const AstRawString* name = ParseIdentifier(kAllowEvalOrArguments, CHECK_OK);
-  ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
+  Scanner::Location spread_pos;
+  ZoneList<Expression*>* args = ParseArguments(&spread_pos, CHECK_OK);
+
+  // TODO(caitp): support intrinsics
+  DCHECK(!spread_pos.IsValid());
 
   if (extension_ != NULL) {
     // The extension structures are only accessible while parsing the
     // very first time not when reparsing because of lazy compilation.
     scope_->DeclarationScope()->ForceEagerCompilation();
   }
 
   const Runtime::Function* function = Runtime::FunctionForName(name->string());
 
   // Check for built-in IS_VAR macro.
@@ skipping 1299 matching lines @@
           running_hash, data, raw_string->length());
     } else {
       const uc16* data = reinterpret_cast<const uc16*>(raw_string->raw_data());
       running_hash = StringHasher::ComputeRunningHash(running_hash, data,
                                                       raw_string->length());
     }
   }
 
   return running_hash;
 }
+
+
+ZoneList<v8::internal::Expression*>* Parser::PrepareSpreadArguments(
+    ZoneList<v8::internal::Expression*>* list) {
+  ZoneList<v8::internal::Expression*>* args =
+      new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
+  if (list->length() == 1) {
+    args->Add(
+        factory()->NewCallRuntime(ast_value_factory()->spread_iterable_string(),
+                                  NULL, list, RelocInfo::kNoPosition),
+        zone());
+    return args;
+  } else {
+    int i = 0;

[arv (Not doing code reviews), 2015/02/23 17:55:56]

This could use a comment explaining what it desugars to.

[rossberg, 2015/02/25 14:28:18]

+1

[caitp (gmail), 2015/02/25 14:49:08]

Acknowledged.

+    int n = list->length();
+    while (i < n) {
+      ZoneList<v8::internal::Expression*>* unspread =
+          new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
+
+      // Push array of unspread parameters
+      while (i < n && !list->at(i)->IsSpreadOperation()) {
+        unspread->Add(list->at(i++), zone());
+      }
+      int literal_index = function_state_->NextMaterializedLiteralIndex();
+      args->Add(factory()->NewArrayLiteral(unspread, literal_index,

[arv (Not doing code reviews), 2015/02/23 17:55:56]

Will this be observable if someone overrides Array.prototoype[Symbol.iterator]?

[caitp (gmail), 2015/02/25 14:49:08]

The unspread array literals aren't iterated via iterator protocol, so no. Could
be observable if the length property were defined though.

+                                           RelocInfo::kNoPosition),
+                zone());
+
+      if (i == n) break;
+
+      // Push eagerly spread argument
+      ZoneList<v8::internal::Expression*>* spread =
+          new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
+      spread->Add(list->at(i++), zone());
+      args->Add(factory()->NewCallRuntime(
+                    ast_value_factory()->spread_iterable_string(), NULL, spread,
+                    RelocInfo::kNoPosition),
+                zone());
+    }
+
+    list = new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
+    list->Add(factory()->NewCallRuntime(
+                  ast_value_factory()->spread_arguments_string(), NULL, args,
+                  RelocInfo::kNoPosition),
+              zone());
+    return list;
+  }
+  UNREACHABLE();
+}
+
+
+Expression* Parser::SpreadCall(Expression* function,
+                               ZoneList<v8::internal::Expression*>* args,
+                               int pos) {
+  Expression* receiver;
+  if (function->IsProperty()) {
+    receiver = function->AsProperty()->obj();
+  } else {
+    receiver = factory()->NewUndefinedLiteral(pos);
+  }
+
+  args->InsertAt(0, function, zone());
+  args->InsertAt(1, receiver, zone());
+
+  const Runtime::Function* apply = Runtime::FunctionForId(Runtime::kApply);
+  return factory()->NewCallRuntime(ast_value_factory()->empty_string(), apply,
+                                   args, pos);
+}
+
+
+Expression* Parser::SpreadCallNew(Expression* function,
+                                  ZoneList<v8::internal::Expression*>* args,
+                                  int pos) {
+  args->InsertAt(0, function, zone());
+
+  const Runtime::Function* apply =
+      Runtime::FunctionForId(Runtime::kApplyConstruct);
+  return factory()->NewCallRuntime(ast_value_factory()->empty_string(), apply,
+                                   args, pos);
+}
 } }  // namespace v8::internal