https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116424
--- Comment #16 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:5eca4dc76ded61a959447bd11d1edf6d4030a51d commit r13-9251-g5eca4dc76ded61a959447bd11d1edf6d4030a51d Author: Marek Polacek <pola...@redhat.com> Date: Tue Aug 27 18:25:17 2024 -0400 c++: ICE with ()-init and TARGET_EXPR eliding [PR116424] Here we crash on a cp_gimplify_expr/TARGET_EXPR assert: gcc_checking_assert (!TARGET_EXPR_ELIDING_P (*expr_p) || !TREE_ADDRESSABLE (TREE_TYPE (*expr_p))); We cannot elide the TARGET_EXPR because we're taking its address. It is set as eliding in massage_init_elt. I've tried to not set TARGET_EXPR_ELIDING_P when the context is not direct-initialization. That didn't work: even when it's not direct-initialization now, it can become one later, for instance, after split_nonconstant_init. One problem is that replace_placeholders_for_class_temp_r will replace placeholders in non-eliding TARGET_EXPRs with the slot, but if we then elide the TARGET_EXPR, we end up with a "stray" VAR_DECL and crash. (Only some TARGET_EXPRs are handled by replace_decl.) I thought I'd have to go back to <https://gcc.gnu.org/pipermail/gcc-patches/2024-May/651163.html> but then I realized that this problem occurrs only with ()-init but not {}-init. With {}-init, there is no problem, because we are clearing TARGET_EXPR_ELIDING_P in process_init_constructor_record: /* We can't actually elide the temporary when initializing a potentially-overlapping field from a function that returns by value. */ if (ce->index && TREE_CODE (next) == TARGET_EXPR && unsafe_copy_elision_p (ce->index, next)) TARGET_EXPR_ELIDING_P (next) = false; But that does not happen for ()-init because we have no ce->index. ()-init doesn't allow brace elision so we don't really reshape them. But I can just move the clearing a few lines down and then it handles both ()-init and {}-init. PR c++/116424 gcc/cp/ChangeLog: * typeck2.cc (process_init_constructor_record): Move the clearing of TARGET_EXPR_ELIDING_P down. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/paren-init38.C: New test. (cherry picked from commit 15f857af2943a4aa282d04ff71f860352ad3291b)
