I see, thanks Andrew. Anyone else have opinions on this besides Liu or Andrew? The responses have been surprisingly quiet thus far
best regards, Julian On Wed, 5 Jul 2023, 09:40 Andrew Pinski, <pins...@gmail.com> wrote: > On Tue, Jul 4, 2023 at 6:32 PM Julian Waters <tanksherma...@gmail.com> > wrote: > > > > Hi Andrew, thanks for the quick response, > > > > What if the method has a return value? I know it sounds > counterintuitive, but in some places HotSpot relies on the noreturn > attribute being applied to methods that do return a value in an unreachable > code path. Does the unreachable builtin cover that case too? > > It is wrong to use noreturn on a function other than one which has a > return type of void as documented. > > https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noreturn-function-attribute > : > ``` > It does not make sense for a noreturn function to have a return type > other than void. > ``` > > Thanks, > Andrew Pinski > > > > > > best regards. > > Julian > > > > On Wed, Jul 5, 2023 at 9:07 AM Andrew Pinski <pins...@gmail.com> wrote: > >> > >> On Tue, Jul 4, 2023 at 5:54 PM Julian Waters via Gcc <gcc@gcc.gnu.org> > wrote: > >> > > >> > Hi all, > >> > > >> > Currently to disable the warning that a noreturn method does return, > it's > >> > required to disable warnings entirely. This can be very inconvenient > when > >> > -Werror is enabled with a noreturn method that isn't specifically > calling > >> > something like std::abort() at the end, when one wants all other > -Wall and > >> > -Wextra warnings to be reported, for instance in the Java HotSpot VM > (which > >> > I'm currently adapting to compile with gcc on all supported > platforms). Is > >> > there a possibility we can add a disable warning option specifically > for > >> > this case? Something like -Wno-returning-noreturn. I'm interested in > adding > >> > this myself if it's not convenient for gcc's maintainers to do so at > the > >> > moment, but I'd need some guidance on where to look and what the > relevant > >> > code is > >> > >> You could just add > >> __builtin_unreachable(); (or std::unreachable(); if you are C++23 or > >> unreachable() if you are using C23). > >> Or even add while(true) ; > >> > >> I am pretty sure not having an option is on purpose and not really > >> interested in adding an option here because of the above workarounds. > >> > >> Thanks, > >> Andrew Pinski > >> > >> > > >> > best regards, > >> > Julian >
