https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67436
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |ice-on-valid-code
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-09-02
Ever confirmed|0 |1
Known to fail| |6.0
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Johannes S. Mueller-Roemer from comment #0)
> I encountered an error with a missing __tls_init after using a thread_local
> variable within a generic lambda. I was able to work around this bug by
> creating a reference to the thread_local and using the reference in the
> lambda instead.
That sounds similar to an example discussed by the committee recently:
void f() {
thread_local int n = 10;
std::thread([&] { std::cout << n << std::endl; }).join();
}
The reference to n inside the lambda is to the variable in the new thread,
which was never initialized because the flow of control never reached its
initializer. This is probably a defect in the standard.
> I was not able to reproduce the exact same behavior with a minimal example,
> however this code
>
> int main(int, char**)
> {
> thread_local int foo;
> [&] (auto bar) {
> foo += bar;
> }(1u);
> return 0;
> }
>
> Causes an internal compiler error
Confirmed, also ICEs on trunk.
