Replace passive effect context with boolean (#18309)

packages/react-reconciler/src/ReactFiberWorkLoop.js

@@ -199,14 +199,13 @@ const {
 
 type ExecutionContext = number;
 
-const NoContext = /*                    */ 0b0000000;
-const BatchedContext = /*               */ 0b0000001;
-const EventContext = /*                 */ 0b0000010;
-const DiscreteEventContext = /*         */ 0b0000100;
-const LegacyUnbatchedContext = /*       */ 0b0001000;
-const RenderContext = /*                */ 0b0010000;
-const CommitContext = /*                */ 0b0100000;
-const PassiveEffectContext = /*         */ 0b1000000;
+const NoContext = /*                    */ 0b000000;
+const BatchedContext = /*               */ 0b000001;
+const EventContext = /*                 */ 0b000010;
+const DiscreteEventContext = /*         */ 0b000100;
+const LegacyUnbatchedContext = /*       */ 0b001000;
+const RenderContext = /*                */ 0b010000;
+const CommitContext = /*                */ 0b100000;
 
 type RootExitStatus = 0 | 1 | 2 | 3 | 4 | 5;
 const RootIncomplete = 0;
@@ -299,6 +298,10 @@ let spawnedWorkDuringRender: null | Array<ExpirationTime> = null;
 // receive the same expiration time. Otherwise we get tearing.
 let currentEventTime: ExpirationTime = NoWork;
 
+// Dev only flag that tracks if passive effects are currently being flushed.
+// We warn about state updates for unmounted components differently in this case.
+let isFlushingPassiveEffects = false;
+
 export function getWorkInProgressRoot(): FiberRoot | null {
   return workInProgressRoot;
 }
@@ -2273,6 +2276,10 @@ function flushPassiveEffectsImpl() {
     return false;
   }
 
+  if (__DEV__) {
+    isFlushingPassiveEffects = true;
+  }
+
   const root = rootWithPendingPassiveEffects;
   const expirationTime = pendingPassiveEffectsExpirationTime;
   rootWithPendingPassiveEffects = null;
@@ -2284,7 +2291,6 @@ function flushPassiveEffectsImpl() {
   );
   const prevExecutionContext = executionContext;
   executionContext |= CommitContext;
-  executionContext |= PassiveEffectContext;
   const prevInteractions = pushInteractions(root);
 
   if (runAllPassiveEffectDestroysBeforeCreates) {
@@ -2448,6 +2454,10 @@ function flushPassiveEffectsImpl() {
   nestedPassiveUpdateCount =
     rootWithPendingPassiveEffects === null ? 0 : nestedPassiveUpdateCount + 1;
 
+  if (__DEV__) {
+    isFlushingPassiveEffects = false;
+  }
+
   return true;
 }
 
@@ -2816,7 +2826,7 @@ function warnAboutUpdateOnUnmountedFiberInDEV(fiber) {
     }
 
     // If we are currently flushing passive effects, change the warning text.
-    if ((executionContext & PassiveEffectContext) !== NoContext) {
+    if (isFlushingPassiveEffects) {
       console.error(
         "Can't perform a React state update from within a useEffect cleanup function. " +
           'To fix, move state updates to the useEffect() body in %s.%s',