Am 09.10.19 um 11:19 schrieb Jonathan Wakely: > On Wed, 9 Oct 2019 at 04:49, Klaus Doldinger wrote: >> >> Hi all, >> >> following is an example regarding the generation of guards for the >> static m in template X. > > I didn't check the implementation, but according to the documentation, > -fno-threadsafe-statics only affects local static, so it's > unsurprising that it doesn't have any effect on a static member > variable. > > For the local static variable, GCC and Clang still emit the guard > variable with -fno-threadsafe-statics but they do not emit the code to > use that variable (there are no calls to __cxa_guard_acquire or > __cxa_guard_release). I believe the guard variable stills gets be > emitted for ABI reasons, because another translation unit compiled > without -fno-threadsafe-statics might be expecting it to exist. > Ok. Looks like constinit (C++20) and a constexpr user-defined ctor could solve the problem. Thanks for pointing me into the right direction.
