Move useMemoCache hook to react/compiler-runtime

For Meta-internal purposes, we keep the export on `react` itself to reduce churn.

packages/react-debug-tools/src/__tests__/ReactHooksInspectionIntegration-test.js

@@ -37,7 +37,7 @@ describe('ReactHooksInspectionIntegration', () => {
     ReactDOM = require('react-dom');
     act = require('internal-test-utils').act;
     ReactDebugTools = require('react-debug-tools');
-    useMemoCache = React.unstable_useMemoCache;
+    useMemoCache = require('react/jsx-runtime').c;
   });
 
   it('should inspect the current state of useState hooks', async () => {

packages/react-devtools-shell/src/app/InspectableElements/UseMemoCache.js

@@ -1,7 +1,8 @@
 import * as React from 'react';
+import {c} from 'react/compiler-runtime';
 
 export default function UseMemoCache(): React.Node {
-  React.unstable_useMemoCache(1);
+  c(1);
 
   return null;
 }

packages/react-reconciler/src/ReactInternalTypes.js

@@ -416,7 +416,7 @@ export type Dispatcher = {
   ): T,
   useId(): string,
   useCacheRefresh?: () => <T>(?() => T, ?T) => void,
-  useMemoCache?: (size: number) => Array<any>,
+  useMemoCache: (size: number) => Array<any>,
   useHostTransitionStatus?: () => TransitionStatus,
   useOptimistic?: <S, A>(
     passthrough: S,

packages/react-reconciler/src/__tests__/useMemoCache-test.js

@@ -27,8 +27,8 @@ describe('useMemoCache()', () => {
     Scheduler = require('scheduler');
     act = require('internal-test-utils').act;
     assertLog = require('internal-test-utils').assertLog;
+    useMemoCache = require('react/compiler-runtime').c;
     useState = React.useState;
-    useMemoCache = React.unstable_useMemoCache;
     MemoCacheSentinel = Symbol.for('react.memo_cache_sentinel');
 
     class _ErrorBoundary extends React.Component {

packages/react/index.classic.fb.js

@@ -36,7 +36,6 @@ export {
   unstable_SuspenseList,
   unstable_getCacheForType,
   unstable_useCacheRefresh,
-  unstable_useMemoCache,
   useId,
   useCallback,
   useContext,
@@ -57,4 +56,12 @@ export {
   useActionState,
   version,
 } from './src/ReactClient';
+
 export {jsx, jsxs, jsxDEV} from './src/jsx/ReactJSX';
+
+// export for backwards compatibility during upgrade
+export {useMemoCache as unstable_useMemoCache} from './src/ReactHooks';
+
+// export to match the name of the OSS function typically exported from
+// react/compiler-runtime
+export {useMemoCache as c} from './src/ReactHooks';

packages/react/index.experimental.js

@@ -34,7 +34,6 @@ export {
   unstable_getCacheForType,
   unstable_SuspenseList,
   unstable_useCacheRefresh,
-  unstable_useMemoCache,
   useId,
   useCallback,
   useContext,

packages/react/index.js

@@ -57,7 +57,6 @@ export {
   unstable_TracingMarker,
   unstable_getCacheForType,
   unstable_useCacheRefresh,
-  unstable_useMemoCache,
   useId,
   useCallback,
   useContext,

packages/react/index.modern.fb.js

@@ -36,7 +36,6 @@ export {
   unstable_TracingMarker,
   unstable_getCacheForType,
   unstable_useCacheRefresh,
-  unstable_useMemoCache,
   useId,
   useCallback,
   useContext,
@@ -58,3 +57,10 @@ export {
   version,
 } from './src/ReactClient';
 export {jsx, jsxs, jsxDEV} from './src/jsx/ReactJSX';
+
+// export for backwards compatibility during upgrade
+export {useMemoCache as unstable_useMemoCache} from './src/ReactHooks';
+
+// export to match the name of the OSS function typically exported from
+// react/compiler-runtime
+export {useMemoCache as c} from './src/ReactHooks';

packages/react/package.json

@@ -34,6 +34,10 @@
       "react-server": "./jsx-dev-runtime.react-server.js",
       "default": "./jsx-dev-runtime.js"
     },
+    "./compiler-runtime": {
+      "react-server": "./compiler-runtime.js",
+      "default": "./compiler-runtime.js"
+    },
     "./src/*": "./src/*"
   },
   "repository": {

packages/react/src/ReactClient.js

@@ -55,7 +55,6 @@ import {
   useId,
   useCacheRefresh,
   use,
-  useMemoCache,
   useOptimistic,
   useActionState,
 } from './ReactHooks';
@@ -117,7 +116,6 @@ export {
   getCacheForType as unstable_getCacheForType,
   useCacheRefresh as unstable_useCacheRefresh,
   use,
-  useMemoCache as unstable_useMemoCache,
   // enableScopeAPI
   REACT_SCOPE_TYPE as unstable_Scope,
   // enableTransitionTracing

packages/react/src/compiler-runtime.js

@@ -0,0 +1,8 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export {useMemoCache as c} from './src/ReactHooks';

packages/shared/ReactFeatureFlags.js

@@ -102,7 +102,7 @@ export const enableSuspenseAvoidThisFallbackFizz = false;
 
 export const enableCPUSuspense = __EXPERIMENTAL__;
 
-// Enables unstable_useMemoCache hook, intended as a compilation target for
+// Enables useMemoCache hook, intended as a compilation target for
 // auto-memoization.
 export const enableUseMemoCacheHook = __EXPERIMENTAL__;
 // Test this at Meta before enabling.

scripts/rollup/bundles.js

@@ -115,6 +115,17 @@ const bundles = [
     externals: ['react', 'ReactNativeInternalFeatureFlags'],
   },
 
+  /******* Compiler Runtime *******/
+  {
+    bundleTypes: [NODE_DEV, NODE_PROD, NODE_PROFILING],
+    moduleType: ISOMORPHIC,
+    entry: 'react/compiler-runtime',
+    global: 'CompilerRuntime',
+    minifyWithProdErrorCodes: true,
+    wrapWithModuleBoundaries: false,
+    externals: ['react'],
+  },
+
   /******* React JSX Runtime React Server *******/
   {
     bundleTypes: [NODE_DEV, NODE_PROD],