On Thu, Nov 3, 2011 at 8:50 PM, Jason Merrill <ja...@redhat.com> wrote: > 12.2 states that a temporary bound to a reference lives as long as the > reference itself. We have done that for reference variables, but not in > other cases, such as aggregate initialization of a struct with reference > members. In C++11, elements of a std::initializer_list have the same > semantics; they live as long as the std::initializer_list. Again, we were > implementing that for initializer_list variables but not for > initializer_list subobjects. This patch fixes that. > > Furthermore, if a temporary's lifetime is extended, we need to also extend > the lifetimes of any temporaries bound to references in its initializer, and > so on. > > The patch introduces a function extend_ref_init_temps called from > store_init_value after the call to digest_init. To expose elements of an > initializer_list to this function, I needed to stop using > build_aggr_init_full_exprs for aggregate initialization of arrays, and > consequently needed to call build_vec_init from store_init_value to use one > EH region for cleaning up the whole array rather than one per element. To > deal with multiple extended temporaries, we need to change the cleanup > pointer from a single tree to a VEC, and add a discriminator to the mangled > name of reference init temporaries; this has no ABI impact, since the > temporaries have no linkage, but I also updated the demangler accordingly. > > Since we now do lifetime extension in extend_ref_init_temps, we can > drastically simplify initialize_reference and do away with > build_init_list_var_init. > > Tested x86_64-pc-linux-gnu, applying to trunk.
This caused: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53650 -- H.J.
