https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82235
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |mpolacek at gcc dot gnu.org
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Some debugging notes.
We're synthesizing the Bar::Bar(const Bar&) constructor in
do_build_copy_constructor which creates a list of Bar's fields along with their
initializers. Here we have
m D.2398->m
because we're initializing m from m of a copy. We pass this list down to
finish_mem_initializers, which passes each pair to perform_member_init.
perform_member_init sees that we're initializing an array so creates a
VEC_INIT_EXPR via build_vec_init_expr.
VEC_INIT_EXPRs are expanded in cp_gimplify_expr, so we call build_vec_init to
do so. We're initializing an array from another array and so do
4508 else if (type_build_ctor_call (type))
4509 elt_init = build_aggr_init (to, from, 0, complain)
where to = *D.2445 and from = *D.2447.
and build_aggr_init has
1822 if (init && init != void_type_node
1823 && TREE_CODE (init) != TREE_LIST
1824 && !(TREE_CODE (init) == TARGET_EXPR
1825 && TARGET_EXPR_DIRECT_INIT_P (init))
1826 && !DIRECT_LIST_INIT_P (init))
1827 flags |= LOOKUP_ONLYCONVERTING;
and init is an indirect_ref so we set L_O, never realizing that in this case we
don't want to set L_O.
I suppose we could introduce VEC_INIT_EXPR_DIRECT_INIT_P, set it in
perform_member_init, and then use it in cp_gimplify_expr to let build_aggr_init
know not to set L_O. Because cp_gimplify_expr can't know in what context the
VEC_INIT_EXPR was created.
