[promises] cleanup default promise handlers

src/builtins/builtins-promise.cc

 // Copyright 2016 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/builtins/builtins-promise.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 #include "src/code-factory.h"
 #include "src/code-stub-assembler.h"
@@ skipping 402 matching lines @@
   Node* const result = InternalPerformPromiseThen(
       context, promise, on_resolve, on_reject, var_deferred_promise.value(),
       var_deferred_on_resolve.value(), var_deferred_on_reject.value());
   return result;
 }
 
 Node* PromiseBuiltinsAssembler::InternalPerformPromiseThen(
     Node* context, Node* promise, Node* on_resolve, Node* on_reject,
     Node* deferred_promise, Node* deferred_on_resolve,
     Node* deferred_on_reject) {
-  Node* const native_context = LoadNativeContext(context);
 
   Variable var_on_resolve(this, MachineRepresentation::kTagged),
       var_on_reject(this, MachineRepresentation::kTagged);
 
   var_on_resolve.Bind(on_resolve);
   var_on_reject.Bind(on_reject);
 
   Label out(this), if_onresolvenotcallable(this), onrejectcheck(this),
       append_callbacks(this);
   GotoIf(TaggedIsSmi(on_resolve), &if_onresolvenotcallable);
 
+  Isolate* isolate = this->isolate();
   Node* const on_resolve_map = LoadMap(on_resolve);
   Branch(IsCallableMap(on_resolve_map), &onrejectcheck,
          &if_onresolvenotcallable);
 
   Bind(&if_onresolvenotcallable);
   {
-    var_on_resolve.Bind(LoadContextElement(
-        native_context, Context::PROMISE_ID_RESOLVE_HANDLER_INDEX));
+    Isolate* isolate = this->isolate();
+    Node* const default_resolve_handler_symbol = HeapConstant(
+        isolate->factory()->promise_default_resolve_handler_symbol());
+    var_on_resolve.Bind(default_resolve_handler_symbol);
     Goto(&onrejectcheck);
   }
 
   Bind(&onrejectcheck);
   {
     Label if_onrejectnotcallable(this);
     GotoIf(TaggedIsSmi(on_reject), &if_onrejectnotcallable);
 
     Node* const on_reject_map = LoadMap(on_reject);
     Branch(IsCallableMap(on_reject_map), &append_callbacks,
            &if_onrejectnotcallable);
 
     Bind(&if_onrejectnotcallable);
     {
-      var_on_reject.Bind(LoadContextElement(
-          native_context, Context::PROMISE_ID_REJECT_HANDLER_INDEX));
+      Node* const default_reject_handler_symbol = HeapConstant(
+          isolate->factory()->promise_default_reject_handler_symbol());
+      var_on_reject.Bind(default_reject_handler_symbol);
       Goto(&append_callbacks);
     }
   }
 
   Bind(&append_callbacks);
   {
     Label fulfilled_check(this);
     Node* const status = LoadObjectField(promise, JSPromise::kStatusOffset);
     GotoUnless(SmiEqual(status, SmiConstant(v8::Promise::kPending)),
                &fulfilled_check);
@@ skipping 789 matching lines @@
 
   Bind(&promisehook_before);
   {
     GotoUnless(IsPromiseHookEnabledOrDebugIsActive(), &run_handler);
     CallRuntime(Runtime::kPromiseHookBefore, context, deferred_promise);
     Goto(&run_handler);
   }
 
   Bind(&run_handler);
   {
-    Callable call_callable = CodeFactory::Call(isolate);
-    Node* const result =
-        CallJS(call_callable, context, handler, UndefinedConstant(), value);
+    Label if_defaulthandler(this), if_callablehandler(this),
+        if_internalhandler(this), if_customhandler(this, Label::kDeferred);
+    Variable var_result(this, MachineRepresentation::kTagged);
 
-    GotoIfException(result, &if_rejectpromise, &var_reason);
+    Branch(IsSymbol(handler), &if_defaulthandler, &if_callablehandler);
 
-    Label if_internalhandler(this), if_customhandler(this, Label::kDeferred);
-    Branch(IsUndefined(deferred_on_resolve), &if_internalhandler,
-           &if_customhandler);
+    Bind(&if_defaulthandler);
+    {
+      Label if_resolve(this), if_reject(this);
+      Node* const default_resolve_handler_symbol = HeapConstant(
+          isolate->factory()->promise_default_resolve_handler_symbol());
+      Branch(WordEqual(default_resolve_handler_symbol, handler), &if_resolve,
+             &if_reject);
+
+      Bind(&if_resolve);
+      {
+        var_result.Bind(value);
+        Branch(IsUndefined(deferred_on_resolve), &if_internalhandler,
+               &if_customhandler);
+      }
+
+      Bind(&if_reject);
+      {
+        var_reason.Bind(value);
+        Goto(&if_rejectpromise);
+      }
+    }
+
+    Bind(&if_callablehandler);
+    {
+      Callable call_callable = CodeFactory::Call(isolate);
+      Node* const result =
+          CallJS(call_callable, context, handler, UndefinedConstant(), value);
+      var_result.Bind(result);
+      GotoIfException(result, &if_rejectpromise, &var_reason);
+      Branch(IsUndefined(deferred_on_resolve), &if_internalhandler,
+             &if_customhandler);
+    }
 
     Bind(&if_internalhandler);
-    InternalResolvePromise(context, deferred_promise, result);
+    InternalResolvePromise(context, deferred_promise, var_result.value());
     Goto(&promisehook_after);
 
     Bind(&if_customhandler);
     {
+      Callable call_callable = CodeFactory::Call(isolate);
       Node* const maybe_exception =
           CallJS(call_callable, context, deferred_on_resolve,
-                 UndefinedConstant(), result);
+                 UndefinedConstant(), var_result.value());
       GotoIfException(maybe_exception, &if_rejectpromise, &var_reason);
       Goto(&promisehook_after);
     }
   }
 
   Bind(&if_rejectpromise);
   {
     Callable promise_handle_reject = CodeFactory::PromiseHandleReject(isolate);
     CallStub(promise_handle_reject, context, deferred_promise,
              deferred_on_reject, var_reason.value());
@@ skipping 229 matching lines @@
   Node* const reason = Parameter(2);
   Node* const debug_event = Parameter(3);
   Node* const context = Parameter(6);
 
   InternalPromiseReject(context, promise, reason, debug_event);
   Return(UndefinedConstant());
 }
 
 }  // namespace internal
 }  // namespace v8