refactor(ios): remove clang VFS overlay, resolve headers via new ReactNativeHeaders framework#57285
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`yarn format-check` (prettier) was failing CI on PR #57285. Run prettier on the ios-prebuild headers scripts (headers-compose.js, headers-inventory.js), replace-rncore-version.js, and __docs__/README.md so format-check passes. No logic changes. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The minimal machinery to build the packaged header structures: - headers-spec.js: the executable layout contract (rules R1-R8) — which namespaces are hoisted into the React framework, which carry module maps, and how collisions are rejected. - headers-inventory.js: scans the source tree and classifies every shipped header (language surface + modularizability bucket) — the input to the spec. computeInventory() feeds the build in-memory; the CLI writes a JSON manifest. - headers-compose.js: emits the layout — writes the <React/...> headers + umbrella + module map into each React.framework slice (detected by the framework's presence), and assembles the headers-only ReactNativeHeaders.xcframework (every other namespace + deps + Hermes). Called by xcframework.js during compose. This is the alternative header source that lets consumers resolve React Native headers without a clang VFS overlay. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Emit the headers-spec layout unconditionally and delete the VFS overlay across
JS, CI publish, and Ruby. Consumers resolve headers the way the SwiftPM branch
does: <React/...> from the vendored React.framework, every other namespace from
ReactNativeHeaders. No root Headers/ on the xcframework, no VFS.
JS:
- xcframework.js: always emit the React.framework spec layout and build
ReactNativeHeaders.xcframework (was gated behind RN_ZERO_I_LAYOUT=1). Remove
the legacy header path entirely — the podspec->root-Headers enumeration,
createModuleMapFile, and copyHeaderFilesToSlices — so the published
React.xcframework is a standard framework (Info.plist + per-slice
React.framework/{Headers,Modules}), no root Headers/ or Modules/. Ship
ReactNativeHeaders.xcframework inside the reactnative-core tarball (sibling of
React.xcframework) so the prebuilt pod can vend both; keep the standalone
ReactNativeHeaders.xcframework.tar.gz for the SPM path. Drop the
React-VFS-template.yaml emit and the ./vfs import.
- vfs.js: deleted (its only consumer was xcframework.js).
- types.js: drop the now-unused VFSEntry/VFSOverlay/HeaderMapping types.
- replace-rncore-version.js: drop the React-VFS.yaml preservation rationale.
Ruby/CocoaPods:
- React-Core-prebuilt.podspec: vend React.xcframework (its per-slice
React.framework + module map serves <React/...> and @import React via
FRAMEWORK_SEARCH_PATHS); flatten ReactNativeHeaders' headers into a top-level
Headers/ in prepare_command and expose them via the pod header search path.
Drop the VFS-era root header_mappings_dir/module_map.
- rncore.rb: remove the -ivfsoverlay injection and process_vfs_overlay;
add_rncore_dependency and configure_aggregate_xcconfig now add a
HEADER_SEARCH_PATHS to React-Core-prebuilt/Headers for podspec, aggregate, and
third-party targets.
- react_native_pods.rb: drop the process_vfs_overlay post-install call.
Docs: replace the "VFS Overlay System" section with the headers-spec layout;
drop the obsolete "Known Issues" (pre-headers-spec) section.
Verified end-to-end: prebuild compose produces a VFS-free, root-Headers-free
React.xcframework; rn-tester pod install + xcodebuild (prebuilt path) BUILD
SUCCEEDED with zero -ivfsoverlay.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
React.framework is a clang module; when an SPM consumer precompiles it, a
modular React/ header that #imports <react/...> hit
-Wnon-modular-include-in-framework-module because the lowercase react/
namespace (served from ReactNativeHeaders, per R1's Linux/Windows-safe layout)
was deliberately kept out of any module.
Give react/ a module where it already lives instead of relocating it (relocation
would require case-folding react.framework -> React.framework, which only works
on case-insensitive filesystems):
- headers-spec.js: drop the react/ namespace-module exemption so its
objc-modular-candidates get a module; emit that module as
ReactNativeHeaders_react (a module literally named 'react' would alias the
React framework module on a case-insensitive filesystem). Module names are
internal; <react/...> still resolves by header path and is now modular.
- headers-inventory.js: classify C++ default member initializers in aggregates
(e.g. struct { NSString *family = nil; } in RCTFontProperties.h) as ObjC++ so
these are not misclassified objc-modular-candidate and pulled into a plain
ObjC module they cannot compile in.
The unguarded ObjC/C react/ headers (e.g. JSRuntimeFactoryCAPI.h) now resolve
modularly; the C++ react/renderer/* includes are #ifdef __cplusplus-guarded and
skipped during the ObjC module emit, so they need no module.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
In prebuilt mode the React core pods' code + headers live entirely in React.xcframework / React-Core-prebuilt. Re-installing their SOURCE podspecs made them ship duplicate headers that shadow the prebuilt artifact and break the React framework's clang explicit-module precompile (-Wnon-modular-include-in-framework-module) under Xcode 26. Install those core pods as dependency-only FACADES instead: generated podspecs with no sources/headers, installed via :path (so nothing is fetched), each depending on React-Core-prebuilt. Version, subspecs, default_subspec and resources (e.g. the privacy manifest) are DERIVED from the real podspec so the facade stays graph- and resource-equivalent to the source pod. With the shadowing gone the React module precompiles cleanly with SWIFT_ENABLE_EXPLICIT_MODULES on, so the Xcode-26 workaround (#53457) is removed. The prebuilt header search path + ReactNativeHeaders module-map activation are consolidated into a single post-install injection site (configure_aggregate_xcconfig); add_rncore_dependency now only declares the React-Core-prebuilt dependency. rn-tester's NativeComponentExample uses the canonical <React/...> include for RCTFabricComponentsPlugins.h (resolved from the framework) so it builds against the facaded React-RCTFabric in prebuilt mode. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
`yarn format-check` (prettier) was failing CI on PR #57285. Run prettier on the ios-prebuild headers scripts (headers-compose.js, headers-inventory.js), replace-rncore-version.js, and __docs__/README.md so format-check passes. No logic changes. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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…tarball The prebuilt React core now ships two xcframeworks — React.xcframework and the headers-only ReactNativeHeaders.xcframework. React-Core-prebuilt's prepare_command flattens the latter's Headers (including module.modulemap) into the pod. The compose step only tar'd React.xcframework, so consumers got no React-Core-prebuilt/Headers/module.modulemap and failed the build with "module map file ... not found". Tar both xcframeworks. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
…le (R9) The public-umbrella model (which replaced the VFS overlay) excludes `+Private` and objc-blocked headers from React.framework's module, so privileged framework consumers (e.g. Expo) that `#import <React/RCTBridge+Private.h>`, `<React/RCTMountingManager.h>`, etc. fail to compile under explicit modules even though the headers still ship in React.framework/Headers. Add R9: a curated allowlist appended to the React module map — `RCTBridge+Private.h` as a real `header` (objc-modular-candidate, reaches no C++) and the six Fabric headers as `textual header` (objc-blocked; a real member would re-trip -Wnon-modular-include, and their <react/...> C++ includes resolve at the consumer's use site). Backwards-compatible: existing `#import <React/...>` (and Swift `import React`) sites are unchanged. Fails closed if an allowlisted header is removed/renamed or drifts bucket. Note: RCTUIKit.h / RCTRootContentView.h are absent from source entirely and need restoration, not exposure — out of scope here.
The flattened ReactNativeHeaders layout ships the individual React_RCTAppDelegate/*.h headers but no per-namespace umbrella. Consumers like Expo probe `<React_RCTAppDelegate/React_RCTAppDelegate-umbrella.h>` via __has_include (RCTAppDelegateUmbrella.h); with the umbrella gone the probe fails and RCTReactNativeFactory / RCTRootViewFactory are never declared, breaking the Expo pod's clang module. Add R10: emit a per-namespace umbrella (content DERIVED from namespaceModules so it can't drift — e.g. RCTArchConfiguratorProtocol.h, gone from this branch, is correctly omitted) and add it to that namespace's module so the import stays modular under explicit modules. Targeted via UMBRELLA_NAMESPACES (currently just React_RCTAppDelegate, the only umbrella Expo imports); fails closed if a listed namespace loses its modular headers.
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Summary
The prebuilt React.xcframework previously relied on a Clang VFS overlay (React-VFS.yaml) to make headers importable, because the headers were laid out in CocoaPods-style namespaced folders rather than standard framework conventions. The overlay had to be generated at build time, re-resolved at pod-install time per slice, and injected as
-ivfsoverlayflags into every Obj-C, C++, and Swift compile (including aggregate and third-party pod targets).This is fragile, hard to reason about, and incompatible with SwiftPM consumption.
This PR removes the VFS overlay entirely and resolves headers through standard framework/header-search-path mechanics instead.
Headers are now emitted into the artifact according to an explicit, executable spec:
<React/...>header plus a framework module map, so#import <React/...>and@import Reactresolve throughFRAMEWORK_SEARCH_PATHSautomatically.<react/...>,<yoga/...>,folly,glog, …), shipped alongside in the prebuilt tarball and exposed via a single header search path.ReactNativeDependenciesbinary-only.No clang VFS overlay, no per-target
-ivfsoverlayflags. The layout is driven by a single source of truth (headers-spec.js, rules R1–R8) that both the prebuild compose step and downstream SwiftPM tooling derive from, so the shipped header set cannot drift from the spec.Source headers are byte-identical to the repo — the only consumer-facing changes needed is bare-form angle includes (
#import <RCTAppDelegate.h>→#import <React/RCTAppDelegate.h>).Key changes
headers-spec.js(the executable layout contract),headers-compose.js(emitter for both xcframeworks),headers-inventory.js(podspec-driven header classifier feeding the spec + a diagnostic manifest).vfs.js, VFS types intypes.js, and the VFS processing/flag-injection paths inrncore.rbandxcframework.js.React-Core-prebuilt.podspec(vends both xcframeworks, flattens ReactNativeHeaders headers into Headers/ via prepare_command),rncore.rb/react_native_pods.rb(header search path instead of overlay flags), README (VFS docs replaced with the new model).Changelog:
[IOS] [CHANGED] - Remove the Clang VFS overlay from prebuilt React Native Core; resolve headers via React.xcframework + a new headers-only ReactNativeHeaders.xcframework
Test Plan
React.xcframeworkandReactNativeHeaders.xcframeworkpod install flattens headers into React-Core-prebuilt/Headers.React.xcframeworkandReactNativeHeaders.xcframeworkare changed between debug and release correctly.