fix(iOS): exclude C++-guarded foreign-namespace headers from React umbrella#57575
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fix(iOS): exclude C++-guarded foreign-namespace headers from React umbrella#57575chrfalch wants to merge 1 commit into
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…brella The prebuilt React-Core artifact's generated module.modulemap placed RCTFrameTimingsObserver.h in the React umbrella. That header includes <jsinspector-modern/tracing/FrameTimingSequence.h> under #ifdef __cplusplus, transitively reaching react/timing/primitives.h — a header owned by the ReactNativeHeaders_react module. The headers inventory's reachability fixpoint only follows unguarded include edges (modeling a pure-ObjC consumer), so it could not see this edge and classified the header as umbrella-safe. For Swift pods with C++ interop (e.g. react-native-unistyles), building the React clang module opens the __cplusplus guard, and primitives.h ends up owned by two modules in one compilation: C++ redefinition errors (HighResDuration, HighResTimeStamp, TraceEvent, FrameTimingSequence) and "could not build module 'React'". This broke the react-native-unistyles job in nightly-tests on 0.88.0-nightly-20260716. Fix: add a curated UMBRELLA_CXX_GUARDED_EXCLUSIONS set, checked in isUmbrellaSafe, mirroring the existing PRIVATE_REACT_HEADERS pattern, with fail-closed validation (validateUmbrellaExclusions) so a renamed or deleted entry surfaces immediately. The header still ships in React.framework/Headers and remains importable via #import <React/RCTFrameTimingsObserver.h>; it is only removed from the modular umbrella surface. Co-Authored-By: Claude Fable 5 <[email protected]>
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Summary:
The first nightly containing the prebuilt/SwiftPM stack (
0.88.0-nightly-20260716) broke thereact-native-unistylesjob in react-native-community/nightly-tests with:Root cause:
RCTFrameTimingsObserver.hincludes<jsinspector-modern/tracing/FrameTimingSequence.h>under#ifdef __cplusplus, transitively reachingreact/timing/primitives.h, which is owned by theReactNativeHeaders_reactmodule. The headers inventory's reachability fixpoint only follows unguarded include edges (modeling a pure-ObjC consumer), so it couldn't see this edge and classified the header as umbrella-safe. Swift pods with C++ interop (unistyles, Nitro-based libs) build theReactclang module as ObjC++, opening the guard — one header owned by two modules in a single compilation → C++ redefinition errors. Pure-ObjC consumers never open the guard, which is why only C++-interop libraries failed.Fix: a curated
UMBRELLA_CXX_GUARDED_EXCLUSIONSset checked inisUmbrellaSafe, mirroring the existingPRIVATE_REACT_HEADERSpattern, with fail-closed validation (validateUmbrellaExclusions, wired intoplanFromInventory) so a renamed/deleted entry surfaces immediately.The header still ships in
React.framework/Headersand stays importable via#import <React/RCTFrameTimingsObserver.h>(its only consumer today isRCTHost.mm); it is only removed from the modular umbrella surface. If a modular consumer ever needs it, it can be promoted to aPRIVATE_REACT_HEADERS.textual-style entry instead.Changelog:
[IOS] [FIXED] - Fix "redefinition of 'HighResDuration'" / "could not build module 'React'" when building Swift pods with C++ interop against the prebuilt React-Core artifact
Test Plan:
scripts/ios-prebuild/__tests__/headers-spec-test.js: the excluded header is kept out of the umbrella (fails against the previous code withReceived array: ["React/RCTFrameTimingsObserver.h"]), and exclusion drift fails closed.RCT_USE_RN_DEP=1 RCT_USE_PREBUILT_RNCORE=1).🤖 Generated with Claude Code