[ios][precompile] add support for clang virtual file system by chrfalch · Pull Request #54842 · facebook/react-native

chrfalch · 2025-12-10T14:15:26Z

Summary:

To solve our problem with header files from the React.XCFramework not being consumable due to the legacy Cocoapods headers, we used to point all header search / resolving into the Pods/Headers folder when building even with the framework installed.

This is a problem since an xcframework expects a modular header structure that can be consumed from within the headers folder of the framework.

The headers are used for both Objective-c compiling and for creating clang modules that can be consumed by Swift in our setup.

This commit fixes the above issues and makes a modular clang virtual file system from the header files we distribute. This vfs-overlay file will then be used by the rncore.rb script when installing the 'React-Core-prebuilt' pod and map the header files requested in the source code to the actual location on disk where the React.xcframework headers are installed.

Here are the changes:

Added vfs.js with types for creating clang virtual file system overlays
Added resolving the paths in the vfs file to the actual install path
Added installing the vfs overlay with the switch -ivfsoverlay <path> to compiler settings for both obj-c and swift on pod installation
Add vfs targets to the app target on post install

Prev PR: #54841

Changelog:

[IOS] [FIXED] - added support for clang virtual file system in React.XCFramework

Test Plan:

Run RNTester with prebuilt

github-actions · 2025-12-10T14:24:27Z

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github-actions · 2025-12-10T16:39:45Z

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github-actions · 2025-12-11T09:06:54Z

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cipolleschi

It makes sense. I trust that you tested it out!

packages/react-native/scripts/ios-prebuild/vfs.js

meta-codesync · 2026-01-14T11:10:43Z

@cipolleschi has imported this pull request. If you are a Meta employee, you can view this in D90674493.

cortinico

Review automatically exported from Phabricator review in Meta.

cipolleschi · 2026-01-26T16:25:22Z

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


 require_relative './utils.rb'

 ### Adds ReactNativeCore-prebuilt as a dependency to the given podspec if we're not


from @cortinico

is this stale?

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

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

Replace the regex-based approach for parsing podspec files with a declarative configuration system for header file collection: Add headers-config.js with explicit podspec configurations defining header patterns, directories, and subspecs - Add vfs.js to generate VFS overlay YAML files for Clang virtual file system support - Refactor headers.js to use the new configuration-based approach with support for nested subspecs and path preservation - Update xcframework.js to handle the new header mapping structure with source/target paths - This provides more reliable and maintainable header file collection for XCFramework builds by avoiding fragile regex parsing of Ruby podspec files.

Now it reads from podspec files, except for some special cases that we have in the config file. Updated RCTSwiftUIWrapper.podspec to use podspec_sources (which we use to detect source) I tested this against the header files I got with the previous iteration, and also with the ones installed by Cocoapods.

To solve our problem with header files from the React.XCFramework not being consumable due to the legacy Cocoapods headers, we used to point all header search / resolving into the Pods/Headers folder when building even with the framework installed. This is a problem since an xcframework expects a modular header structure that can be consumed from within the headers folder of the framework. The headers are used for both Objective-c compiling and for creating clang modules that can be consumed by Swift in our setup. This commit fixes the above issues and makes a modular clang virtual file system from the header files we distribute. This vfs-overlay file will then be used by the `rncore.rb` script when installing the 'React-Core-prebuilt' pod and map the header files requested in the source code to the actual location on disk where the React.xcframework headers are installed. Here are the changes: - Added vfs.js with types for creating clang virtual file system overlays - Added resolving the paths in the vfs file to the actual install path - Added installing the vfs overlay with the switch `-ivfsoverlay <path>` to compiler settings for both obj-c and swift on pod installation - Add vfs targets to the app target on post install

Had some podspecs with header_dir set to a variable that wasn't emitted correctly in the VFS file. This commit fixes this by adding explicit reading of header-dir as well as exceptions for the specs that had variables. - Tested comparing the output from a regular pod install with the generated header files. - Tested with RNTester - Tested in BareExpo with prebuild Expo modules and full compile.

Tried to build some smartness in last comitt - not working in a generic way so I reverted it. This is handled by the exception in header-config.js instead.

…te targets when installing This one uses installer.pod_targets.each to do this. Added helper function to avoid code ducplication.

Summary: Replace the regex-based approach for parsing podspec files with a declarative configuration system for header file collection: Add headers-config.js with explicit podspec configurations defining header patterns, directories, and subspecs - Add vfs.js to generate VFS overlay YAML files for Clang virtual file system support - Refactor headers.js to use the new configuration-based approach with support for nested subspecs and path preservation - Update xcframework.js to handle the new header mapping structure with source/target paths - This provides more reliable and maintainable header file collection for XCFramework builds by avoiding fragile regex parsing of Ruby podspec files. Prev PR: #54840 Next PR: #54842 bypass-github-export-checks ## Changelog: [IOS] [FIXED] - refactored header files generator for prebuilt React framework Pull Request resolved: #54841 Test Plan: Run RNTester with prebuilt Reviewed By: cortinico Differential Revision: D90674355 Pulled By: cipolleschi fbshipit-source-id: 66ec997a8731b6bf91a8f3c2ab42a94e7b0601e8

meta-codesync · 2026-01-27T22:35:28Z

@cipolleschi merged this pull request in f0422ab.

… on iOS (#55394) Summary: When the user switches from Debug -> Release we'll replace the React-Core-prebuilt XCFramework. Previously we nuked the ios/Pods/React-Core-prebuilt folder - but after we added support for VFS overlays to honor header files in the XCFramework this folder will also contain the VFS-file (React-VFS.yaml) which shouldn't be removed. Removing this file causes an error when building. This commit fixes this by deleting all directories inside the Pods/React-Core-prebuilt folder, leaving any files (React-VFS.yaml) untouched. I've tested this in a new project and in RN-Tester and it works. I measured the size of the XCFramework when switching between Debug/Release to confirm that the switch still works. I also changed the name of the podspec script since it showd RNDeps and not RNCore. This issue was introduced in #54842 and not yet released in any version. ## Changelog: [IOS] [FIXED] - Fixed replace script deleting the react-vfs.yaml file on iOS Pull Request resolved: #55394 Test Plan: Run RN-Tester with precompiled binaries and build both release and debug. Reviewed By: cortinico Differential Revision: D92159099 Pulled By: cipolleschi fbshipit-source-id: 3ae7bd03431b225672ac4b4f7b91e6ef44765019

chrfalch requested a review from cipolleschi December 10, 2025 14:15

meta-cla bot added the CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. label Dec 10, 2025

facebook-github-bot added p: Expo Partner: Expo Partner Shared with Meta Applied via automation to indicate that an Issue or Pull Request has been shared with the team. labels Dec 10, 2025

chrfalch force-pushed the chrfalch/react-precompile-add-vfs-support branch from 3e2aec1 to ed64fda Compare December 11, 2025 08:58

cipolleschi changed the base branch from main to chrfalch/react-precompile-refactor-header-file-generator December 16, 2025 15:58

cipolleschi approved these changes Dec 16, 2025

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packages/react-native/scripts/ios-prebuild/vfs.js Outdated Show resolved Hide resolved

cipolleschi approved these changes Dec 17, 2025

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cipolleschi mentioned this pull request Dec 17, 2025

[ios][precompile] refactor header files generator for prebuilt React framework #54841

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chrfalch force-pushed the chrfalch/react-precompile-refactor-header-file-generator branch from d0c3305 to b1fdfaf Compare January 5, 2026 13:43

chrfalch force-pushed the chrfalch/react-precompile-add-vfs-support branch from ba99f11 to 2ddcbd1 Compare January 5, 2026 13:45

chrfalch changed the base branch from chrfalch/react-precompile-refactor-header-file-generator to main January 5, 2026 13:45

cortinico approved these changes Jan 21, 2026

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cipolleschi approved these changes Jan 26, 2026

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chrfalch added 9 commits January 26, 2026 20:15

codereview: removed superflous parameter

6097ca6

Reverted unneeded change after adding exceptions

961b199

Tried to build some smartness in last comitt - not working in a generic way so I reverted it. This is handled by the exception in header-config.js instead.

Added exception for Yoga to preserve directories

2943685

codereview: removed toPosix function

78a668d

testing: we need to addd vfs overlay to all targets, not only aggrega…

7fea6c5

…te targets when installing This one uses installer.pod_targets.each to do this. Added helper function to avoid code ducplication.

chrfalch force-pushed the chrfalch/react-precompile-add-vfs-support branch from 2ddcbd1 to 7fea6c5 Compare January 26, 2026 19:15

codereivew: added missing log

ea1abc3

chrfalch added 2 commits January 26, 2026 20:36

codereview: updated readme and added reference

ab9b5a5

codereview: lint fix

4a30613

meta-codesync bot closed this in f0422ab Jan 27, 2026

facebook-github-bot added the Merged This PR has been merged. label Jan 27, 2026

chrfalch mentioned this pull request Feb 3, 2026

fix(precompile) fixed replace script deleting the react-vfs.yaml file on iOS #55394

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[ios][precompile] add support for clang virtual file system#54842

[ios][precompile] add support for clang virtual file system#54842
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chrfalch/react-precompile-add-vfs-support

chrfalch commented Dec 10, 2025 •

edited by cipolleschi

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		require_relative './utils.rb'

		### Adds ReactNativeCore-prebuilt as a dependency to the given podspec if we're not

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chrfalch commented Dec 10, 2025 •

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