fix: Bring back Cxx TurboModule autolinking via `registerCxxModuleToG…

…lobalModuleMap` (#46360)

Summary:
Reverts the PR #45967 from philIip to bring back the `registerCxxModuleToGlobalModuleMap(..)` function, which I use in Nitro Modules and MMKV.

Ontop of that, this also removes the "experimental" `RCT_EXPORT_CXX_MODULE_EXPERIMENTAL` macro, which I think was the original intent of this PR as this macro is a bit unsafe.

I also added some small docs to `registerCxxModuleToGlobalModuleMap` while I'm at it.

## Changelog:

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[GENERAL] [CHANGED] - Bring back CxxTurboModule autolinking function, but remove `RCT_EXPORT_CXX_MODULE_EXPERIMENTAL` macro

[ANDROID|GENERAL|IOS|INTERNAL] [BREAKING|ADDED|CHANGED|DEPRECATED|REMOVED|FIXED|SECURITY] - Message

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Pull Request resolved: #46360

Test Plan: Build Nitro Modules. Worked for me! :)

Reviewed By: realsoelynn

Differential Revision: D62310637

Pulled By: philIip

fbshipit-source-id: 2caa2b8ea094dda5e13c81431a9a645cbcf8f807

packages/react-native/ReactAndroid/src/main/jni/react/turbomodule/ReactCommon/TurboModuleManager.cpp

@@ -15,6 +15,7 @@
 #include <jsi/jsi.h>
 
 #include <ReactCommon/BindingsInstallerHolder.h>
+#include <ReactCommon/CxxTurboModuleUtils.h>
 #include <ReactCommon/JavaInteropTurboModule.h>
 #include <ReactCommon/TurboCxxModule.h>
 #include <ReactCommon/TurboModuleBinding.h>
@@ -168,6 +169,14 @@ std::shared_ptr<TurboModule> TurboModuleManager::getTurboModule(
     return cxxModule;
   }
 
+  auto& cxxTurboModuleMapProvider = globalExportedCxxTurboModuleMap();
+  auto it = cxxTurboModuleMapProvider.find(name);
+  if (it != cxxTurboModuleMapProvider.end()) {
+    auto turboModule = it->second(jsCallInvoker_);
+    turboModuleCache_.insert({name, turboModule});
+    return turboModule;
+  }
+
   static auto getTurboJavaModule =
       javaPart->getClass()
           ->getMethod<jni::alias_ref<JTurboModule>(const std::string&)>(

packages/react-native/ReactCommon/react/nativemodule/core/ReactCommon/CxxTurboModuleUtils.cpp

@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+
+#include "CxxTurboModuleUtils.h"
+
+namespace facebook::react {
+
+std::unordered_map<
+    std::string,
+    std::function<
+        std::shared_ptr<TurboModule>(std::shared_ptr<CallInvoker> jsInvoker)>>&
+globalExportedCxxTurboModuleMap() {
+  static std::unordered_map<
+      std::string,
+      std::function<std::shared_ptr<TurboModule>(
+          std::shared_ptr<CallInvoker> jsInvoker)>>
+      map;
+  return map;
+}
+
+void registerCxxModuleToGlobalModuleMap(
+    std::string name,
+    std::function<std::shared_ptr<TurboModule>(
+        std::shared_ptr<CallInvoker> jsInvoker)> moduleProviderFunc) {
+  globalExportedCxxTurboModuleMap()[name] = moduleProviderFunc;
+}
+
+} // namespace facebook::react

packages/react-native/ReactCommon/react/nativemodule/core/ReactCommon/CxxTurboModuleUtils.h

@@ -0,0 +1,35 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <string>
+#include <unordered_map>
+
+#include <ReactCommon/CallInvoker.h>
+#include <ReactCommon/TurboModule.h>
+
+namespace facebook::react {
+
+std::unordered_map<
+    std::string,
+    std::function<
+        std::shared_ptr<TurboModule>(std::shared_ptr<CallInvoker> jsInvoker)>>&
+globalExportedCxxTurboModuleMap();
+
+/**
+ * Registers the given C++ TurboModule initializer function
+ * in the global module map.
+ * This needs to be called before the TurboModule is requested from JS,
+ * for example in a `+ load`, your AppDelegate's start, or from Java init.
+ */
+void registerCxxModuleToGlobalModuleMap(
+    std::string name,
+    std::function<std::shared_ptr<TurboModule>(
+        std::shared_ptr<CallInvoker> jsInvoker)> moduleProviderFunc);
+
+} // namespace facebook::react

packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModuleManager.mm

@@ -29,6 +29,7 @@
 #import <React/RCTPerformanceLogger.h>
 #import <React/RCTRuntimeExecutorModule.h>
 #import <React/RCTUtils.h>
+#import <ReactCommon/CxxTurboModuleUtils.h>
 #import <ReactCommon/RCTTurboModuleWithJSIBindings.h>
 #import <ReactCommon/TurboCxxModule.h>
 #import <ReactCommon/TurboModulePerfLogger.h>
@@ -328,6 +329,14 @@ - (instancetype)initWithBridgeProxy:(RCTBridgeProxy *)bridgeProxy
     TurboModulePerfLogger::moduleCreateFail(moduleName, moduleId);
   }
 
+  auto &cxxTurboModuleMapProvider = globalExportedCxxTurboModuleMap();
+  auto it = cxxTurboModuleMapProvider.find(moduleName);
+  if (it != cxxTurboModuleMapProvider.end()) {
+    auto turboModule = it->second(_jsInvoker);
+    _turboModuleCache.insert({moduleName, turboModule});
+    return turboModule;
+  }
+
   /**
    * Step 2: Look for platform-specific modules.
    */