fix(ios): harden prebuilt header layout consumption (review findings)

- copy facade resources into the facade pod dir: CocoaPods file accessors
  cannot glob past the pod root, so the ..-escaping globs shipped the
  privacy-manifest / i18n resource bundles empty
- quote -fmodule-map-file so a PODS_ROOT containing spaces stays a single
  clang argument (matches the quoted HEADER_SEARCH_PATHS beside it)
- fail closed in React-Core-prebuilt's prepare_command and in
  replace-rncore-version.js when the tarball lacks
  ReactNativeHeaders.xcframework, instead of silently leaving an empty or
  deleted Headers/ with the module-map flag dangling
- thread rnRoot through planFromInventory/isUmbrellaSafe instead of the
  hardcoded hosting-package root (the one spot that didn't take the
  inventory's root)
- drop the dead ios-prebuild templates/ files (their only consumers were
  removed by the headers-spec compose)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: chrfalch

packages/react-native/React-Core-prebuilt.podspec

@@ -47,16 +47,25 @@ Pod::Spec.new do |s|
     XCFRAMEWORK_PATH="${CURRENT_PATH}/React.xcframework"
 
     # Flatten ReactNativeHeaders' headers (identical across slices) into Headers/
-    # BEFORE we sweep stray root entries into React.xcframework.
+    # BEFORE we sweep stray root entries into React.xcframework. Fail closed:
+    # a tarball without ReactNativeHeaders.xcframework (an artifact published
+    # before the headers-spec layout, or a truncated download) would otherwise
+    # yield a green install with an empty Headers/ and every <react/...> or
+    # <yoga/...> include failing much later, far from the cause.
     mkdir -p Headers
     RNH_XCFRAMEWORK_PATH=$(find "$CURRENT_PATH" -type d -name "ReactNativeHeaders.xcframework" | head -n 1)
-    if [ -n "$RNH_XCFRAMEWORK_PATH" ]; then
-      RNH_HEADERS_PATH=$(find "$RNH_XCFRAMEWORK_PATH" -type d -name "Headers" | head -n 1)
-      if [ -n "$RNH_HEADERS_PATH" ]; then
-        cp -R "$RNH_HEADERS_PATH/." Headers
-      fi
-      rm -rf "$RNH_XCFRAMEWORK_PATH"
+    if [ -z "$RNH_XCFRAMEWORK_PATH" ]; then
+      echo "[React-Core-prebuilt] ERROR: ReactNativeHeaders.xcframework not found in the prebuilt tarball." >&2
+      echo "The artifact predates the headers-spec layout or is incomplete; use a matching react-native version." >&2
+      exit 1
+    fi
+    RNH_HEADERS_PATH=$(find "$RNH_XCFRAMEWORK_PATH" -type d -name "Headers" | head -n 1)
+    if [ -z "$RNH_HEADERS_PATH" ]; then
+      echo "[React-Core-prebuilt] ERROR: no Headers directory inside $RNH_XCFRAMEWORK_PATH." >&2
+      exit 1
     fi
+    cp -R "$RNH_HEADERS_PATH/." Headers
+    rm -rf "$RNH_XCFRAMEWORK_PATH"
 
     mkdir -p "${XCFRAMEWORK_PATH}"
     find "$CURRENT_PATH" -mindepth 1 -maxdepth 1 \

packages/react-native/scripts/cocoapods/rncore.rb

@@ -563,7 +563,8 @@ def self.add_prebuilt_header_search_paths(attributes, headers_search_path)
         # (`yoga`, `RCTDeprecation`, `ReactNativeHeaders_react`, ...) are modular —
         # otherwise the React framework's clang explicit-module precompile trips
         # -Wnon-modular-include-in-framework-module on `<yoga/...>` / `<react/...>`.
-        module_map_flag = " -fmodule-map-file=$(PODS_ROOT)/React-Core-prebuilt/Headers/module.modulemap"
+        # Quoted so a $(PODS_ROOT) containing spaces stays a single clang argument.
+        module_map_flag = " \"-fmodule-map-file=$(PODS_ROOT)/React-Core-prebuilt/Headers/module.modulemap\""
         ReactNativePodsUtils.add_flag_to_map_with_inheritance(attributes, "OTHER_CFLAGS", module_map_flag)
         ReactNativePodsUtils.add_flag_to_map_with_inheritance(attributes, "OTHER_SWIFT_FLAGS", " -Xcc" + module_map_flag)
     end

packages/react-native/scripts/cocoapods/rncore_facades.rb

@@ -135,8 +135,11 @@ def self.generate(react_native_path, install_root, version, ios_version)
 
             # Preserve non-code RESOURCES (privacy manifest, i18n bundles, ...). They
             # don't shadow headers, and React-Core-prebuilt doesn't vend them, so the
-            # facade must carry them or prebuilt installs lose them. Globs are made
-            # relative to the facade dir so they resolve back to the real source tree.
+            # facade must carry them or prebuilt installs lose them. The matched
+            # files are COPIED into the facade dir (like the re-exposed headers):
+            # CocoaPods file accessors only match globs against files under the pod
+            # root, so a `..`-escaping glob back into the source tree would silently
+            # match nothing and the bundles would ship empty.
             resource_bundles = derive_resource_bundles(real, podspec_dir, dir)
             spec["resource_bundles"] = resource_bundles unless resource_bundles.empty?
             resources = derive_resources(real, podspec_dir, dir)
@@ -209,16 +212,16 @@ def self.derive_subspecs(real)
     end
     private_class_method :derive_subspecs
 
-    # Effective resource_bundles of the real spec (e.g. React-Core_privacy), with
-    # globs rewritten relative to the facade dir so they point back at the real
-    # source files. Unions the `resource_bundle` (singular) and `resource_bundles`
-    # (plural) DSL forms.
+    # Effective resource_bundles of the real spec (e.g. React-Core_privacy),
+    # copied into the facade dir under resources/<bundle>/. Unions the
+    # `resource_bundle` (singular) and `resource_bundles` (plural) DSL forms.
     def self.derive_resource_bundles(real, podspec_dir, facade_dir)
         out = {}
         [real.attributes_hash["resource_bundle"], real.attributes_hash["resource_bundles"]].each do |rb|
             next unless rb.is_a?(Hash)
             rb.each do |bundle, globs|
-                out[bundle] = Array(globs).map { |g| rel_glob(g, podspec_dir, facade_dir) }
+                copied = copy_resources(Array(globs), podspec_dir, facade_dir, File.join("resources", bundle))
+                out[bundle] = copied unless copied.empty?
             end
         end
         out
@@ -248,19 +251,32 @@ def self.copy_reexposed_headers(globs, podspec_dir, facade_dir, name)
     end
     private_class_method :copy_reexposed_headers
 
-    # Loose `resources` of the real spec, rewritten relative to the facade dir.
+    # Loose `resources` of the real spec, copied into the facade dir.
     def self.derive_resources(real, podspec_dir, facade_dir)
-        Array(real.attributes_hash["resources"]).map { |g| rel_glob(g, podspec_dir, facade_dir) }
+        copy_resources(Array(real.attributes_hash["resources"]), podspec_dir, facade_dir, "resources")
     end
     private_class_method :derive_resources
 
-    # Rewrite a glob declared relative to `podspec_dir` into one relative to
-    # `facade_dir`, so the generated facade (which lives under the app's build/)
-    # still resolves the resource in the react-native source tree.
-    def self.rel_glob(glob, podspec_dir, facade_dir)
-        require "pathname"
-        abs = File.expand_path(glob, podspec_dir)
-        Pathname.new(abs).relative_path_from(Pathname.new(facade_dir)).to_s
+    # Copies everything the resource globs match (files or whole directories,
+    # e.g. *.lproj bundles) into `<facade_dir>/<subdir>/` and returns
+    # facade-relative paths for the copies. Globs resolve against the real
+    # podspec dir. A glob that matches nothing is tolerated — the source pod
+    # would ship nothing for it either, so the facade stays equivalent.
+    # rm_rf-before-cp_r keeps the snapshot fresh across repeated `pod install`s.
+    def self.copy_resources(globs, podspec_dir, facade_dir, subdir)
+        copied = []
+        globs.each do |g|
+            matches = Dir.glob(File.expand_path(g, podspec_dir))
+            next if matches.empty?
+            dest_dir = File.join(facade_dir, subdir)
+            FileUtils.mkdir_p(dest_dir)
+            matches.each do |src|
+                FileUtils.rm_rf(File.join(dest_dir, File.basename(src)))
+                FileUtils.cp_r(src, dest_dir)
+                copied << File.join(subdir, File.basename(src))
+            end
+        end
+        copied.uniq
     end
-    private_class_method :rel_glob
+    private_class_method :copy_resources
 end

packages/react-native/scripts/ios-prebuild/headers-compose.js

@@ -37,7 +37,7 @@ const path = require('path');
  * artifact must not be produced.
  */
 function computeSpecPlan(rnRoot /*: string */) /*: HeadersSpecPlan */ {
-  const plan = planFromInventory(computeInventory(rnRoot));
+  const plan = planFromInventory(computeInventory(rnRoot), rnRoot);
   if (plan.collisions.length > 0) {
     throw new Error(
       `headers-spec collisions (R8):\n  ${plan.collisions.join('\n  ')}`,

packages/react-native/scripts/ios-prebuild/headers-spec.js

@@ -61,6 +61,9 @@
 const fs = require('fs');
 const path = require('path');
 
+// Fallback root only — inventory `source` paths are relative to the root the
+// inventory was computed from, so callers with a different tree (SPM tooling,
+// headers-inventory --root) must pass that root to planFromInventory.
 const RN_ROOT = path.join(__dirname, '..', '..');
 
 /*::
@@ -164,13 +167,13 @@ function validatePrivateReactHeaders(manifest /*: any */) /*: void */ {
   }
 }
 
-function isUmbrellaSafe(h /*: any */) /*: boolean */ {
+function isUmbrellaSafe(h /*: any */, rnRoot /*: string */) /*: boolean */ {
   if (h.bucket !== 'objc-modular-candidate' || h.naturalPath.includes('+')) {
     return false;
   }
   try {
     return !EXTERN_INLINE_RE.test(
-      fs.readFileSync(path.join(RN_ROOT, h.identities[0].source), 'utf8'),
+      fs.readFileSync(path.join(rnRoot, h.identities[0].source), 'utf8'),
     );
   } catch {
     return false;
@@ -206,8 +209,15 @@ function renderNamespaceUmbrella(
 /**
  * Computes the full layout plan from the header inventory manifest
  * (build/header-inventory.json — regenerate with header-inventory.js).
+ * `rnRoot` is the tree the inventory's relative `source` paths resolve
+ * against; defaults to the manifest's recorded root, then to the package
+ * hosting this script.
  */
-function planFromInventory(manifest /*: any */) /*: HeadersSpecPlan */ {
+function planFromInventory(
+  manifest /*: any */,
+  rnRoot /*:: ?: string */,
+) /*: HeadersSpecPlan */ {
+  const root = rnRoot ?? manifest.root ?? RN_ROOT;
   validatePrivateReactHeaders(manifest); // R9: fail closed on allowlist drift
   const react /*: Array<SpecEntry> */ = [];
   const reactNativeHeaders /*: Array<SpecEntry> */ = [];
@@ -248,7 +258,7 @@ function planFromInventory(manifest /*: any */) /*: HeadersSpecPlan */ {
     entryList.push({relPath, source, naturalPath: np});
 
     // R4: React umbrella membership.
-    if (np.startsWith('React/') && isUmbrellaSafe(h)) {
+    if (np.startsWith('React/') && isUmbrellaSafe(h, root)) {
       umbrella.push(np);
     }
     // R5: namespace modules (only for ReactNativeHeaders namespaces). Every
@@ -260,7 +270,7 @@ function planFromInventory(manifest /*: any */) /*: HeadersSpecPlan */ {
     // case-insensitive filesystem.
     if (entryList === reactNativeHeaders) {
       const ns = np.split('/')[0];
-      if (MODULE_IDENT_RE.test(ns) && isUmbrellaSafe(h)) {
+      if (MODULE_IDENT_RE.test(ns) && isUmbrellaSafe(h, root)) {
         if (!namespaceModules[ns]) {
           namespaceModules[ns] = [];
         }