On Wed, Jun 10, 2026 at 08:15:31AM +0200, Jakub Jelinek wrote: > Hi! > > The following testcase shows that declaring std::initializer_list<T> > with bases can lead to ICEs, right now we were just testing that > it is a class template, not a union, and contains one pointer member > and one size_t member. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Looks good (not an approval). > 2026-06-09 Jakub Jelinek <[email protected]> > > PR c++/125647 > * class.cc (finish_struct): Reject std::initializer_list template > with bases. > > * g++.dg/cpp0x/initlist134.C: New test. > > --- gcc/cp/class.cc.jj 2026-06-02 08:15:04.582141780 +0200 > +++ gcc/cp/class.cc 2026-06-09 12:09:17.352024884 +0200 > @@ -8370,6 +8370,8 @@ finish_struct (tree t, tree attributes) > } > /* It also cannot be a union. */ > ok &= NON_UNION_CLASS_TYPE_P (t); > + if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t))) > + ok = false; > if (!ok) > fatal_error (input_location, "definition of %qD does not match " > "%<#include <initializer_list>%>", TYPE_NAME (t)); > --- gcc/testsuite/g++.dg/cpp0x/initlist134.C.jj 2026-06-09 > 12:14:39.307861068 +0200 > +++ gcc/testsuite/g++.dg/cpp0x/initlist134.C 2026-06-09 12:19:58.905734199 > +0200 > @@ -0,0 +1,18 @@ > +// PR c++/125647 > +// { dg-do compile { target c++11 } } > + > +struct A { int a; }; > +namespace std { > + template <class T> > + class initializer_list : A { T *d; decltype (sizeof 0) s; }; // { > dg-error "definition of 'class std::initializer_list<T>' does not match > '#include <initializer_list>'" } > +} > + > +void foo (std::initializer_list <int>); > + > +void > +bar () > +{ > + foo ({ 1, 2, 3 }); > +} > + > +// { dg-prune-output "compilation terminated" } > > Jakub > Marek
