ES6 symbols: Implement Symbol intrinsic and basic functionality

src/hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4617 matching lines @@
       HHasInstanceTypeAndBranch* typecheck =
           new(zone()) HHasInstanceTypeAndBranch(return_value,
                                                 FIRST_SPEC_OBJECT_TYPE,
                                                 LAST_SPEC_OBJECT_TYPE);
       HBasicBlock* if_spec_object = graph()->CreateBasicBlock();
       HBasicBlock* not_spec_object = graph()->CreateBasicBlock();
       typecheck->SetSuccessorAt(0, if_spec_object);
       typecheck->SetSuccessorAt(1, not_spec_object);
       current_block()->Finish(typecheck);
       if_spec_object->AddLeaveInlined(return_value, state);
-      not_spec_object->AddLeaveInlined(receiver, state);
+      if (!FLAG_harmony_symbols) {
+        not_spec_object->AddLeaveInlined(receiver, state);
+      } else {
+        HHasInstanceTypeAndBranch* symbolcheck =
+          new(zone()) HHasInstanceTypeAndBranch(return_value, SYMBOL_TYPE);
+        HBasicBlock* is_symbol = graph()->CreateBasicBlock();
+        HBasicBlock* not_symbol = graph()->CreateBasicBlock();
+        symbolcheck->SetSuccessorAt(0, is_symbol);
+        symbolcheck->SetSuccessorAt(1, not_symbol);
+        not_spec_object->Finish(symbolcheck);
+        is_symbol->AddLeaveInlined(return_value, state);
+        not_symbol->AddLeaveInlined(receiver, state);
+      }
     }
   } else if (state->inlining_kind() == SETTER_CALL_RETURN) {
     // Return from an inlined setter call. The returned value is never used, the
     // value of an assignment is always the value of the RHS of the assignment.
     CHECK_ALIVE(VisitForEffect(stmt->expression()));
     if (context->IsTest()) {
       HValue* rhs = environment()->arguments_environment()->Lookup(1);
       context->ReturnValue(rhs);
     } else if (context->IsEffect()) {
       current_block()->Goto(function_return(), state);
@@ skipping 4832 matching lines @@
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* value = Pop();
   HHasInstanceTypeAndBranch* result =
       new(zone()) HHasInstanceTypeAndBranch(value,
                                             FIRST_SPEC_OBJECT_TYPE,
                                             LAST_SPEC_OBJECT_TYPE);
   return ast_context()->ReturnControl(result, call->id());
 }
 
 
+void HOptimizedGraphBuilder::GenerateIsSymbol(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  HValue* value = Pop();
+  HHasInstanceTypeAndBranch* result =
+      new(zone()) HHasInstanceTypeAndBranch(value, SYMBOL_TYPE);
+  return ast_context()->ReturnControl(result, call->id());
+}
+
+
 void HOptimizedGraphBuilder::GenerateIsFunction(CallRuntime* call) {
   ASSERT(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* value = Pop();
   HHasInstanceTypeAndBranch* result =
       new(zone()) HHasInstanceTypeAndBranch(value, JS_FUNCTION_TYPE);
   return ast_context()->ReturnControl(result, call->id());
 }
 
 
@@ skipping 1122 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal