[weakrefs] Remove --no-harmony-weak-refs flag

Bug: v8:8179
Change-Id: I7f699073807d1874d0c10a4f1641de6bfb0efe6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2741582
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73871}

src/flags/flag-definitions.h

@@ -259,8 +259,6 @@ DEFINE_BOOL(use_strict, false, "enforce strict mode")
 
 DEFINE_BOOL(harmony, false, "enable all completed harmony features")
 DEFINE_BOOL(harmony_shipping, true, "enable all shipped harmony features")
-// Enabling FinalizationRegistry#cleanupSome also enables weak refs
-DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
 
 // Update bootstrapper.cc whenever adding a new feature flag.
 
@@ -299,7 +297,6 @@ DEFINE_IMPLICATION(harmony_weak_refs_with_cleanup_some, harmony_weak_refs)
 #define HARMONY_SHIPPING_BASE(V)                                  \
   V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")       \
   V(harmony_atomics, "harmony atomics")                           \
-  V(harmony_weak_refs, "harmony weak references")                 \
   V(harmony_regexp_match_indices, "harmony regexp match indices") \
   V(harmony_private_brand_checks, "harmony private brand checks") \
   V(harmony_top_level_await, "harmony top level await")

src/heap/heap.cc

@@ -6277,8 +6277,6 @@ MaybeHandle<JSFinalizationRegistry> Heap::DequeueDirtyJSFinalizationRegistry() {
 }
 
 void Heap::RemoveDirtyFinalizationRegistriesOnContext(NativeContext context) {
-  if (!FLAG_harmony_weak_refs) return;
-
   DisallowGarbageCollection no_gc;
 
   Isolate* isolate = this->isolate();
@@ -6308,7 +6306,6 @@ void Heap::RemoveDirtyFinalizationRegistriesOnContext(NativeContext context) {
 }
 
 void Heap::KeepDuringJob(Handle<JSReceiver> target) {
-  DCHECK(FLAG_harmony_weak_refs);
   DCHECK(weak_refs_keep_during_job().IsUndefined() ||
          weak_refs_keep_during_job().IsOrderedHashSet());
   Handle<OrderedHashSet> table;

src/heap/mark-compact.cc

@@ -2483,9 +2483,6 @@ void MarkCompactCollector::ClearWeakReferences() {
 }
 
 void MarkCompactCollector::ClearJSWeakRefs() {
-  if (!FLAG_harmony_weak_refs) {
-    return;
-  }
   JSWeakRef weak_ref;
   while (weak_objects_.js_weak_refs.Pop(kMainThreadTask, &weak_ref)) {
     HeapObject target = HeapObject::cast(weak_ref.target());

src/heap/weak-object-worklists.cc

@@ -115,19 +115,17 @@ void WeakObjects::UpdateWeakObjectsInCode(
 
 void WeakObjects::UpdateJSWeakRefs(
     WeakObjectWorklist<JSWeakRef>& js_weak_refs) {
-  if (FLAG_harmony_weak_refs) {
-    js_weak_refs.Update(
-        [](JSWeakRef js_weak_ref_in, JSWeakRef* js_weak_ref_out) -> bool {
-          JSWeakRef forwarded = ForwardingAddress(js_weak_ref_in);
-
-          if (!forwarded.is_null()) {
-            *js_weak_ref_out = forwarded;
-            return true;
-          }
-
-          return false;
-        });
-  }
+  js_weak_refs.Update(
+      [](JSWeakRef js_weak_ref_in, JSWeakRef* js_weak_ref_out) -> bool {
+        JSWeakRef forwarded = ForwardingAddress(js_weak_ref_in);
+
+        if (!forwarded.is_null()) {
+          *js_weak_ref_out = forwarded;
+          return true;
+        }
+
+        return false;
+      });
 }
 
 void WeakObjects::UpdateWeakCells(WeakObjectWorklist<WeakCell>& weak_cells) {

src/init/bootstrapper.cc

@@ -3871,6 +3871,61 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     native_context()->set_bound_function_with_constructor_map(*map);
   }
 
+  {  // -- F i n a l i z a t i o n R e g i s t r y
+    Handle<JSFunction> finalization_registry_fun = InstallFunction(
+        isolate_, global, factory->FinalizationRegistry_string(),
+        JS_FINALIZATION_REGISTRY_TYPE, JSFinalizationRegistry::kHeaderSize, 0,
+        factory->the_hole_value(), Builtins::kFinalizationRegistryConstructor);
+    InstallWithIntrinsicDefaultProto(
+        isolate_, finalization_registry_fun,
+        Context::JS_FINALIZATION_REGISTRY_FUNCTION_INDEX);
+
+    finalization_registry_fun->shared().DontAdaptArguments();
+    finalization_registry_fun->shared().set_length(1);
+
+    Handle<JSObject> finalization_registry_prototype(
+        JSObject::cast(finalization_registry_fun->instance_prototype()),
+        isolate());
+
+    InstallToStringTag(isolate_, finalization_registry_prototype,
+                       factory->FinalizationRegistry_string());
+
+    SimpleInstallFunction(isolate_, finalization_registry_prototype, "register",
+                          Builtins::kFinalizationRegistryRegister, 2, false);
+
+    SimpleInstallFunction(isolate_, finalization_registry_prototype,
+                          "unregister",
+                          Builtins::kFinalizationRegistryUnregister, 1, false);
+
+    // The cleanupSome function is created but not exposed, as it is used
+    // internally by InvokeFinalizationRegistryCleanupFromTask.
+    //
+    // It is exposed by FLAG_harmony_weak_refs_with_cleanup_some.
+    Handle<JSFunction> cleanup_some_fun = SimpleCreateFunction(
+        isolate_, factory->InternalizeUtf8String("cleanupSome"),
+        Builtins::kFinalizationRegistryPrototypeCleanupSome, 0, false);
+    native_context()->set_finalization_registry_cleanup_some(*cleanup_some_fun);
+  }
+
+  {  // -- W e a k R e f
+    Handle<JSFunction> weak_ref_fun = InstallFunction(
+        isolate_, global, "WeakRef", JS_WEAK_REF_TYPE, JSWeakRef::kHeaderSize,
+        0, factory->the_hole_value(), Builtins::kWeakRefConstructor);
+    InstallWithIntrinsicDefaultProto(isolate_, weak_ref_fun,
+                                     Context::JS_WEAK_REF_FUNCTION_INDEX);
+
+    weak_ref_fun->shared().DontAdaptArguments();
+    weak_ref_fun->shared().set_length(1);
+
+    Handle<JSObject> weak_ref_prototype(
+        JSObject::cast(weak_ref_fun->instance_prototype()), isolate());
+
+    InstallToStringTag(isolate_, weak_ref_prototype, factory->WeakRef_string());
+
+    SimpleInstallFunction(isolate_, weak_ref_prototype, "deref",
+                          Builtins::kWeakRefDeref, 0, true);
+  }
+
   {  // --- sloppy arguments map
     Handle<String> arguments_string = factory->Arguments_string();
     Handle<JSFunction> function = CreateFunctionForBuiltinWithPrototype(
@@ -4363,75 +4418,8 @@ void Genesis::InitializeGlobal_harmony_atomics() {
   InstallToStringTag(isolate_, isolate()->atomics_object(), "Atomics");
 }
 
-void Genesis::InitializeGlobal_harmony_weak_refs() {
-  if (!FLAG_harmony_weak_refs) return;
-
-  Factory* factory = isolate()->factory();
-  Handle<JSGlobalObject> global(native_context()->global_object(), isolate());
-
-  {
-    // Create %FinalizationRegistry%
-    Handle<JSFunction> finalization_registry_fun = InstallFunction(
-        isolate(), global, factory->FinalizationRegistry_string(),
-        JS_FINALIZATION_REGISTRY_TYPE, JSFinalizationRegistry::kHeaderSize, 0,
-        factory->the_hole_value(), Builtins::kFinalizationRegistryConstructor);
-    InstallWithIntrinsicDefaultProto(
-        isolate(), finalization_registry_fun,
-        Context::JS_FINALIZATION_REGISTRY_FUNCTION_INDEX);
-
-    finalization_registry_fun->shared().DontAdaptArguments();
-    finalization_registry_fun->shared().set_length(1);
-
-    Handle<JSObject> finalization_registry_prototype(
-        JSObject::cast(finalization_registry_fun->instance_prototype()),
-        isolate());
-
-    InstallToStringTag(isolate(), finalization_registry_prototype,
-                       factory->FinalizationRegistry_string());
-
-    SimpleInstallFunction(isolate(), finalization_registry_prototype,
-                          "register", Builtins::kFinalizationRegistryRegister,
-                          2, false);
-
-    SimpleInstallFunction(isolate(), finalization_registry_prototype,
-                          "unregister",
-                          Builtins::kFinalizationRegistryUnregister, 1, false);
-
-    // The cleanupSome function is created but not exposed, as it is used
-    // internally by InvokeFinalizationRegistryCleanupFromTask.
-    //
-    // It is exposed by FLAG_harmony_weak_refs_with_cleanup_some.
-    Handle<JSFunction> cleanup_some_fun = SimpleCreateFunction(
-        isolate(), factory->InternalizeUtf8String("cleanupSome"),
-        Builtins::kFinalizationRegistryPrototypeCleanupSome, 0, false);
-    native_context()->set_finalization_registry_cleanup_some(*cleanup_some_fun);
-  }
-  {
-    // Create %WeakRef%
-    Handle<JSFunction> weak_ref_fun = InstallFunction(
-        isolate(), global, factory->WeakRef_string(), JS_WEAK_REF_TYPE,
-        JSWeakRef::kHeaderSize, 0, factory->the_hole_value(),
-        Builtins::kWeakRefConstructor);
-    InstallWithIntrinsicDefaultProto(isolate(), weak_ref_fun,
-                                     Context::JS_WEAK_REF_FUNCTION_INDEX);
-
-    weak_ref_fun->shared().DontAdaptArguments();
-    weak_ref_fun->shared().set_length(1);
-
-    Handle<JSObject> weak_ref_prototype(
-        JSObject::cast(weak_ref_fun->instance_prototype()), isolate());
-
-    InstallToStringTag(isolate(), weak_ref_prototype,
-                       factory->WeakRef_string());
-
-    SimpleInstallFunction(isolate(), weak_ref_prototype, "deref",
-                          Builtins::kWeakRefDeref, 0, true);
-  }
-}
-
 void Genesis::InitializeGlobal_harmony_weak_refs_with_cleanup_some() {
   if (!FLAG_harmony_weak_refs_with_cleanup_some) return;
-  DCHECK(FLAG_harmony_weak_refs);
 
   Handle<JSFunction> finalization_registry_fun =
       isolate()->js_finalization_registry_fun();

test/cctest/test-js-weak-refs.cc

@@ -209,7 +209,6 @@ Handle<JSWeakRef> MakeWeakRefAndKeepDuringJob(Isolate* isolate) {
 }  // namespace
 
 TEST(TestRegister) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -247,7 +246,6 @@ TEST(TestRegister) {
 }
 
 TEST(TestRegisterWithKey) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -300,7 +298,6 @@ TEST(TestRegisterWithKey) {
 }
 
 TEST(TestWeakCellNullify1) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -335,7 +332,6 @@ TEST(TestWeakCellNullify1) {
 }
 
 TEST(TestWeakCellNullify2) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -369,7 +365,6 @@ TEST(TestWeakCellNullify2) {
 }
 
 TEST(TestJSFinalizationRegistryPopClearedCellHoldings1) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -425,7 +420,6 @@ TEST(TestJSFinalizationRegistryPopClearedCellHoldings1) {
 TEST(TestJSFinalizationRegistryPopClearedCellHoldings2) {
   // Test that when all WeakCells for a key are popped, the key is removed from
   // the key map.
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -476,7 +470,6 @@ TEST(TestJSFinalizationRegistryPopClearedCellHoldings2) {
 }
 
 TEST(TestUnregisterActiveCells) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -529,7 +522,6 @@ TEST(TestUnregisterActiveCells) {
 }
 
 TEST(TestUnregisterActiveAndClearedCells) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -585,7 +577,6 @@ TEST(TestUnregisterActiveAndClearedCells) {
 }
 
 TEST(TestWeakCellUnregisterTwice) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -633,7 +624,6 @@ TEST(TestWeakCellUnregisterTwice) {
 }
 
 TEST(TestWeakCellUnregisterPopped) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -674,7 +664,6 @@ TEST(TestWeakCellUnregisterPopped) {
 }
 
 TEST(TestWeakCellUnregisterNonexistentKey) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -687,7 +676,6 @@ TEST(TestWeakCellUnregisterNonexistentKey) {
 }
 
 TEST(TestJSWeakRef) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
 
@@ -716,7 +704,6 @@ TEST(TestJSWeakRef) {
 }
 
 TEST(TestJSWeakRefIncrementalMarking) {
-  FLAG_harmony_weak_refs = true;
   if (!FLAG_incremental_marking) {
     return;
   }
@@ -752,7 +739,6 @@ TEST(TestJSWeakRefIncrementalMarking) {
 }
 
 TEST(TestJSWeakRefKeepDuringJob) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
 
@@ -790,7 +776,6 @@ TEST(TestJSWeakRefKeepDuringJob) {
 }
 
 TEST(TestJSWeakRefKeepDuringJobIncrementalMarking) {
-  FLAG_harmony_weak_refs = true;
   if (!FLAG_incremental_marking) {
     return;
   }
@@ -819,7 +804,6 @@ TEST(TestJSWeakRefKeepDuringJobIncrementalMarking) {
 }
 
 TEST(TestRemoveUnregisterToken) {
-  FLAG_harmony_weak_refs = true;
   CcTest::InitializeVM();
   LocalContext context;
   Isolate* isolate = CcTest::i_isolate();
@@ -883,7 +867,6 @@ TEST(TestRemoveUnregisterToken) {
 }
 
 TEST(JSWeakRefScavengedInWorklist) {
-  FLAG_harmony_weak_refs = true;
   if (!FLAG_incremental_marking || FLAG_single_generation) {
     return;
   }
@@ -928,7 +911,6 @@ TEST(JSWeakRefScavengedInWorklist) {
 }
 
 TEST(JSWeakRefTenuredInWorklist) {
-  FLAG_harmony_weak_refs = true;
   if (!FLAG_incremental_marking || FLAG_single_generation) {
     return;
   }
@@ -976,7 +958,6 @@ TEST(JSWeakRefTenuredInWorklist) {
 }
 
 TEST(UnregisterTokenHeapVerifier) {
-  FLAG_harmony_weak_refs = true;
   if (!FLAG_incremental_marking) return;
   ManualGCScope manual_gc_scope;
 #ifdef VERIFY_HEAP

test/message/fail/weak-refs-finalizationregistry1.js

@@ -2,6 +2,4 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 let fg = new FinalizationRegistry();

test/message/fail/weak-refs-finalizationregistry1.out

-*%(basename)s:7: TypeError: FinalizationRegistry: cleanup must be callable
+*%(basename)s:*: TypeError: FinalizationRegistry: cleanup must be callable
 let fg = new FinalizationRegistry();
          ^
 TypeError: FinalizationRegistry: cleanup must be callable
     at new FinalizationRegistry (<anonymous>)
-    at *%(basename)s:7:10
+    at *%(basename)s:*:10

test/message/fail/weak-refs-finalizationregistry2.js

@@ -2,6 +2,4 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 let fg = new FinalizationRegistry({});

test/message/fail/weak-refs-finalizationregistry2.out

-*%(basename)s:7: TypeError: FinalizationRegistry: cleanup must be callable
+*%(basename)s:*: TypeError: FinalizationRegistry: cleanup must be callable
 let fg = new FinalizationRegistry({});
          ^
 TypeError: FinalizationRegistry: cleanup must be callable
     at new FinalizationRegistry (<anonymous>)
-    at *%(basename)s:7:10
+    at *%(basename)s:*:10

test/message/fail/weak-refs-register1.js

@@ -2,7 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 let fg = new FinalizationRegistry(() => {});
 fg.register(1);

test/message/fail/weak-refs-register1.out

-*%(basename)s:8: TypeError: FinalizationRegistry.prototype.register: target must be an object
+*%(basename)s:*: TypeError: FinalizationRegistry.prototype.register: target must be an object
 fg.register(1);
    ^
 TypeError: FinalizationRegistry.prototype.register: target must be an object
     at FinalizationRegistry.register (<anonymous>)
-    at *%(basename)s:8:4
+    at *%(basename)s:*:4

test/message/fail/weak-refs-register2.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 let fg = new FinalizationRegistry(() => {});
 let o = {};
 fg.register(o, o);

test/message/fail/weak-refs-register2.out

-*%(basename)s:9: TypeError: FinalizationRegistry.prototype.register: target and holdings must not be same
+*%(basename)s:*: TypeError: FinalizationRegistry.prototype.register: target and holdings must not be same
 fg.register(o, o);
    ^
 TypeError: FinalizationRegistry.prototype.register: target and holdings must not be same
     at FinalizationRegistry.register (<anonymous>)
-    at *%(basename)s:9:4
+    at *%(basename)s:*:4

test/message/fail/weak-refs-unregister.js

@@ -2,7 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 let fg = new FinalizationRegistry(() => {});
 fg.unregister(1);

test/message/fail/weak-refs-unregister.out

-*%(basename)s:8: TypeError: unregisterToken ('1') must be an object
+*%(basename)s:*: TypeError: unregisterToken ('1') must be an object
 fg.unregister(1);
    ^
 TypeError: unregisterToken ('1') must be an object
     at FinalizationRegistry.unregister (<anonymous>)
-    at *%(basename)s:8:4
+    at *%(basename)s:*:4

test/message/weakref-finalizationregistry-error.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 // Flags: --no-stress-opt
 
 // Since cleanup tasks are top-level tasks, errors thrown from them don't stop

test/mjsunit/compiler/monomorphic-named-load-with-no-map.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Flags: --allow-natives-syntax --harmony-weak-refs --expose-gc
+// Flags: --allow-natives-syntax --expose-gc
 
 // Helper to convert setTimeout into an awaitable promise.
 function asyncTimeout(timeout) {

test/mjsunit/harmony/weakrefs/basics.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 (function TestConstructFinalizationRegistry() {
   let fg = new FinalizationRegistry(() => {});
   assertEquals(fg.toString(), "[object FinalizationRegistry]");

test/mjsunit/harmony/weakrefs/cleanup-from-different-realm.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let r = Realm.create();
 

test/mjsunit/harmony/weakrefs/cleanup-is-not-a-microtask.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking --allow-natives-syntax
+// Flags: --expose-gc --noincremental-marking --allow-natives-syntax
 
 // This test asserts that the cleanup function call, scheduled by GC, is a
 // microtask and not a normal task.

test/mjsunit/harmony/weakrefs/cleanup-on-detached-realm.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanedUp = false;
 let r = Realm.create();

test/mjsunit/harmony/weakrefs/cleanup-proxy-from-different-realm.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let r = Realm.create();
 

test/mjsunit/harmony/weakrefs/cleanup.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_called = 0;
 let holdings_list = [];

test/mjsunit/harmony/weakrefs/cleanupsome-optional.js

@@ -5,7 +5,7 @@
 // Flags: --harmony-weak-refs
 
 // FinalizationRegistry#cleanupSome is normative optional and has its own
-// flag. Test that it's not present with only --harmony-weak-refs.
+// flag. Test that it's not present.
 
 assertEquals(undefined, Object.getOwnPropertyDescriptor(
   FinalizationRegistry.prototype, "cleanupSome"));

test/mjsunit/harmony/weakrefs/clearkeptobjects-on-quit.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs
-
 // A newly created WeakRef is kept alive until the end of the next microtask
 // checkpoint. V8 asserts that the kept objects list is cleared at the end of
 // microtask checkpoints when the microtask policy is auto. Test that d8, which

test/mjsunit/harmony/weakrefs/finalizationregistry-and-weakref.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_called = false;
 let cleanup = function(holdings) {

test/mjsunit/harmony/weakrefs/finalizationregistry-independent-lifetime.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_called = false;
 function cleanup(holdings) {

test/mjsunit/harmony/weakrefs/finalizationregistry-keeps-holdings-alive.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_called = false;
 let holdings_list = [];

test/mjsunit/harmony/weakrefs/finalizationregistry-scheduled-for-cleanup-multiple-times.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 // Flags: --no-stress-flush-bytecode
 
 let cleanup0_call_count = 0;

test/mjsunit/harmony/weakrefs/multiple-dirty-finalization-groups.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/reentrant-gc-from-cleanup.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let call_count = 0;
 let reentrant_gc = function(holdings) {

test/mjsunit/harmony/weakrefs/two-weakrefs.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let o1 = {};
 let o2 = {};

test/mjsunit/harmony/weakrefs/undefined-holdings.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-after-cleanup.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-before-cleanup.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking --noincremental-marking
+// Flags: --expose-gc --noincremental-marking --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup = function(holdings) {

test/mjsunit/harmony/weakrefs/unregister-called-twice.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup = function(holdings) {

test/mjsunit/harmony/weakrefs/unregister-inside-cleanup.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-inside-cleanup2.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-inside-cleanup3.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-many.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup_holdings_count = 0;

test/mjsunit/harmony/weakrefs/unregister-when-cleanup-already-scheduled.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_call_count = 0;
 let cleanup = function(holdings) {

test/mjsunit/harmony/weakrefs/weak-cell-basics.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let cleanup_called = false;
 let cleanup = function(holdings_arg) {

test/mjsunit/harmony/weakrefs/weakref-creation-keeps-alive.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let wr;
 (function() {

test/mjsunit/harmony/weakrefs/weakref-deref-keeps-alive.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-weak-refs --expose-gc --noincremental-marking
+// Flags: --expose-gc --noincremental-marking
 
 let wr;
 let wr_control; // control WeakRef for testing what happens without deref

test/unittests/execution/microtask-queue-unittest.cc

@@ -41,7 +41,6 @@ class WithFinalizationRegistryMixin : public TMixin {
   static void SetUpTestCase() {
     CHECK_NULL(save_flags_);
     save_flags_ = new SaveFlags();
-    FLAG_harmony_weak_refs = true;
     FLAG_expose_gc = true;
     FLAG_allow_natives_syntax = true;
     TMixin::SetUpTestCase();