On 10 August 2016 at 15:44, Paolo Bonzini <bonz...@gnu.org> wrote: > > > On 10/08/2016 16:42, Manuel López-Ibáñez wrote: >> > > My only fear is that people not using -Wpedantic nor -pedantic-errors >> > > expect that GNU extensions work. This is a GNU extension that defines >> > > something that is undefined according to ISO. Enabling the warning >> > > with -Wextra is just annoying those people who may not care about >> > > other compilers. >> > >> > I think this warning falls in the same category as >> > -Wshift-negative-value. (In fact I dislike -Wshift-negative-value a >> > lot, and would put that one under -Wpedantic only). >> >> It is not the same category. One is compile-time UB and the other is >> runtime UB. See: >> https://gcc.gnu.org/ml/gcc-patches/2015-04/msg01551.html >> and https://gcc.gnu.org/ml/gcc-patches/2015-04/msg01529.html > > Right---what I meant is it's the same kind of "annoying for people who > expect that GNU extensions work" warning.
Oh, I agree. I'm just mentioning what the current definition/behavior is (and documenting it here: https://gcc.gnu.org/wiki/DiagnosticsGuidelines FWIW), not what I think should be. Perhaps we need something like -Wextra-pedantic, for things that are undefined by ISO C but defined by GNU. Thus, they would not trigger pedwarns and no error with -pedantic-errors. Or we need to split -Wpedantic into -Wpedantic-pedwarns and -Wpedantic-nopedwarns (with better names). This way -pedantic-errors would be equivalent to -Werror=pedantic-pedwarns + -Werror=pedwarns-not-controlled-by-pedantic. i find -pedantic-errors too out of place with the rest of -W* options. Manuel.
