fix(ios): prevent app crash in Release builds#286
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The TurboModule bridge passes a null C++ reference when JS omits the optional roktConfig parameter. The existing guard `&roktConfig != nullptr` is undefined behavior in C++ — the compiler is permitted to assume a reference is never null and remove the check entirely. In Debug builds (-O0) the check survives by accident, so selectPlacements works when run from Xcode. In Release builds (-O2) the compiler optimizes the check away, and the subsequent call to roktConfig.cacheConfig() dereferences address 0x0, producing EXC_BAD_ACCESS (SIGSEGV) on the com.meta.react.turbomodulemanager.queue thread. Because the crash occurs on a background dispatch queue, the placement silently fails to appear with no visible error — partners report "selectPlacements does nothing" rather than a crash. Extracted the roktConfig dictionary conversion into a standalone static function annotated with __attribute__((optnone)) to prevent the compiler from applying UB-based optimizations, ensuring the null reference check is preserved in all build configurations.
jamesnrokt
approved these changes
Mar 5, 2026
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Summary
The TurboModule bridge passes a null C++ reference when JS omits the optional roktConfig parameter. The existing guard
&roktConfig != nullptris undefined behavior in C++ — the compiler is permitted to assume a reference is never null and remove the check entirely. In Debug builds (-O0) the check survives by accident, so selectPlacements works when run from Xcode. In Release builds (-O2) the compiler optimizes the check away, and the subsequent call to roktConfig.cacheConfig() dereferences address 0x0, producing EXC_BAD_ACCESS (SIGSEGV) on the com.meta.react.turbomodulemanager.queue thread.Because the crash occurs on a background dispatch queue, the placement silently fails to appear with no visible error — partners report "selectPlacements does nothing" rather than a crash. Extracted the roktConfig dictionary conversion into a standalone static function annotated with attribute((optnone)) to prevent the compiler from applying UB-based optimizations, ensuring the null reference check is preserved in all build configurations.
Testing Plan
{explain how this has been tested, and what additional testing should be done}
Master Issue
Closes https://go.mparticle.com/work/REPLACEME