Issue #13874: read_null() of faulthandler uses volatile to avoid optimisation
Issue #13874: read_null() of faulthandler uses volatile to avoid optimisation

Clang 3.0 removes "y = *x;" instruction if the optimisation level is 3.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator