[es6] implement spread calls

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 7c2f8feb94bcafc8f2da3dbff5961bce23e37aa0..7d3d8f5967f3e02c6f3c12842ef56230566c6f05 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -878,6 +878,7 @@ Parser::Parser(ParseInfo* info)
   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) {
@@ -4176,6 +4177,8 @@ PreParser::PreParseResult Parser::ParseLazyFunctionBodyWithPreParser(
         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(
@@ -4294,7 +4297,11 @@ Expression* Parser::ParseV8Intrinsic(bool* ok) {
   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
@@ -5562,4 +5569,107 @@ uint32_t Parser::ComputeTemplateLiteralHash(const TemplateLiteral* lit) {
 
   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) {
+    // Spread-call with single spread argument produces an InternalArray
+    // containing the values from the array.
+    //
+    // Function is called or constructed with the produced array of arguments
+    //
+    // EG: Apply(Func, Spread(spread0))
+    args->Add(
+        factory()->NewCallRuntime(ast_value_factory()->spread_iterable_string(),
+                                  NULL, list, RelocInfo::kNoPosition),
+        zone());
+    return args;
+  } else {
+    // Spread-call with multiple arguments produces array literals for each
+    // sequences of unspread arguments, and converts each spread iterable to
+    // an Internal array. Finally, all of these produced arrays are flattened
+    // into a single InternalArray, containing the arguments for the call.
+    //
+    // EG: Apply(Func, Flatten([unspread0, unspread1], Spread(spread0),
+    //                         Spread(spread1), [unspread2, unspread3]))
+    int i = 0;
+    int n = list->length();
+    while (i < n) {
+      if (!list->at(i)->IsSpreadOperation()) {
+        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,
+                                             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;
+  bool is_super = function->IsSuperReference();
+
+  const AstRawString* fn;
+  args->InsertAt(0, function, zone());
+  if (is_super) {
+    fn = ast_value_factory()->reflect_construct_string();
+    args->Add(factory()->NewVariableProxy(scope_->new_target_var()), zone());
+  } else {
+    fn = ast_value_factory()->reflect_apply_string();
+    if (function->IsProperty()) {
+      receiver = function->AsProperty()->obj();
+    } else {
+      receiver = factory()->NewUndefinedLiteral(pos);
+    }
+    args->InsertAt(1, receiver, zone());
+  }
+
+  Expression* result = factory()->NewCallRuntime(fn, NULL, args, pos);
+  if (is_super) {
+    result->AsCallRuntime()->SetIsSuperCall();
+  }
+  return result;
+}
+
+
+Expression* Parser::SpreadCallNew(Expression* function,
+                                  ZoneList<v8::internal::Expression*>* args,
+                                  int pos) {
+  args->InsertAt(0, function, zone());
+
+  return factory()->NewCallRuntime(
+      ast_value_factory()->reflect_construct_string(), NULL, args, pos);
+}
 } }  // namespace v8::internal