On Tue, May 24, 2022 at 04:01:37PM -0400, Jason Merrill wrote: > On 5/24/22 09:55, Marek Polacek wrote: > > On Tue, May 24, 2022 at 08:36:39AM -0400, Jason Merrill wrote: > > > On 5/16/22 11:36, Marek Polacek wrote: > > > > +static tree > > > > +replace_placeholders_for_class_temp_r (tree *tp, int *, void *data) > > > > +{ > > > > + tree t = *tp; > > > > + tree full_expr = *static_cast<tree *>(data); > > > > + > > > > + /* We're looking for a TARGET_EXPR nested in the whole expression. > > > > */ > > > > + if (TREE_CODE (t) == TARGET_EXPR > > > > + && !potential_prvalue_result_of (t, full_expr)) > > > > + { > > > > + tree init = TARGET_EXPR_INITIAL (t); > > > > + while (TREE_CODE (init) == COMPOUND_EXPR) > > > > + init = TREE_OPERAND (init, 1); > > > > > > Hmm, how do we get a COMPOUND_EXPR around a CONSTRUCTOR? > > > > Sadly, that's possible for code like (from nsdmi-aggr18.C) > > > > struct D { > > int x = 42; > > B b = (true, A{x}); > > }; > > > > where the TARGET_EXPR_INITIAL is > > <<< Unknown tree: void_cst >>>, {.x=((struct D *) this)->x, > > .y=(&<PLACEHOLDER_EXPR struct A>)->x} > > Hmm, perhaps cp_build_compound_expr should build an additional TARGET_EXPR > around the COMPOUND_EXPR but leave the one inside alone. Feel free to > investigate that if you'd like, or the patch is OK as is.
Sorry, I was unclear. The whole expression is: TARGET_EXPR <D.2439, A::operator B (&TARGET_EXPR <D.2405, <<< Unknown tree: void_cst >>>, {.x=((struct D *) this)->x, .y=(&<PLACEHOLDER_EXPR struct A>)->x}>)> so there *is* a TARGET_EXPR around the COMPOUND_EXPR. We'd have to build a TARGET_EXPR around the COMPOUND_EXPR's RHS = the CONSTRUCTOR. Frankly, I'm not sure if it's worth the effort. The while loop is somewhat unsightly but not too bad. Marek