add dummy cpp file to cxxstableapi and link cxxstableapi to react-native-fantom

Author: coado

packages/react-native/ReactCommon/react/cxxstableapi/React-cxxstableapi.podspec

@@ -25,7 +25,7 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
-  s.source_files           = podspec_sources("*.h", "*.h")
+  s.source_files           = podspec_sources("*.{cpp,h}", "*.h")
   s.header_dir             = "react/cxxstableapi"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "DEFINES_MODULE" => "YES" }

packages/react-native/ReactCommon/react/cxxstableapi/StableApiAnchor.cpp

@@ -0,0 +1,27 @@
+/*
+ * 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.
+ */
+
+// The cxxstableapi guards are pure preprocessor headers, so this module has
+// nothing to compile. CocoaPods, however, emits a PBXAggregateTarget for a pod
+// with no compilable sources, and an aggregate target produces no .framework
+// under `use_frameworks!`. Dependents' header search paths point at
+// `React_cxxstableapi.framework/Headers`, so without a framework every
+// `#include <react/cxxstableapi/*.h>` fails to resolve.
+//
+// This translation unit exists solely to keep the pod a real framework target.
+// It is deliberately empty apart from the anchor below, which keeps the
+// resulting object file non-empty for linkers that object to one.
+
+namespace facebook::react {
+
+namespace {
+[[maybe_unused]] const char* stableApiAnchor() {
+  return "react/cxxstableapi";
+}
+} // namespace
+
+} // namespace facebook::react

private/react-native-fantom/tester/CMakeLists.txt

@@ -58,6 +58,7 @@ add_react_common_subdir(jsitooling)
 add_react_common_subdir(logger)
 add_react_common_subdir(oscompat)
 add_react_common_subdir(react/bridging)
+add_react_common_subdir(react/cxxstableapi)
 add_react_common_subdir(react/debug)
 add_react_common_subdir(react/featureflags)
 add_react_common_subdir(react/nativemodule/core)