I'm suddenly getting hundreds of these warnings when I build in macOS: /Users/dan/Dev/jdk/jdk/src/hotspot/share/gc/g1/heapRegionSet.hpp:126:5: warning: macro expansion producing 'defined' has undefined behavior [-Wexpansion-to-defined] #if HEAP_REGION_SET_FORCE_VERIFY ^ /Users/dan/Dev/jdk/jdk/src/hotspot/share/gc/g1/heapRegionSet.hpp:53:38: note: expanded from macro 'HEAP_REGION_SET_FORCE_VERIFY' #define HEAP_REGION_SET_FORCE_VERIFY defined(ASSERT) ^
Not clear what triggered them, but my guess is an Xcode update. Is this a known problem? Can anyone reproduce?