https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108117
--- Comment #8 from Feng Xue <fxue at os dot amperecomputing.com> --- (In reply to Andrew Pinski from comment #7) > (In reply to Feng Xue from comment #6) > > (In reply to Andrew Pinski from comment #2) > > > https://en.cppreference.com/w/c/program/setjmp > > > > I think that most programmers are not aware of this, neither I for sure. > > Usage of volatile here is not that intuitive as for purpose of > > multi-execution synchronization > > You should read up on > https://en.cppreference.com/w/cpp/utility/program/signal too. >From viewpoint of programmer, setjmp/longjmp is somewhat similar to C++ exception handling, which happens in one logical execution context, while signal implies two unrelated contexts. In another angle, because gcc already model control flow and SSA web for setjmp/longjmp, explicit volatile specification is not really needed. But signal mechanism is kind of asynchronous exception, for which it is impractical for compiler to do that, so volatile is must.
