https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102594
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:96e0370f4daef29b918aafcff68c7f5e4ef397fd commit r15-3933-g96e0370f4daef29b918aafcff68c7f5e4ef397fd Author: Marek Polacek <pola...@redhat.com> Date: Thu Sep 5 16:45:32 2024 -0400 c++: ICE with structured bindings and m-d array [PR102594] We ICE in decay_conversion with this test: struct S { S() {} }; S arr[1][1]; auto [m](arr3); But not when the last line is: auto [n] = arr3; Therefore the difference is between copy- and direct-init. In particular, in build_vec_init we have: if (direct_init) from = build_tree_list (NULL_TREE, from); and then we call build_vec_init again with init==from. Then decay_conversion gets the TREE_LIST and it crashes. build_aggr_init has: /* Wrap the initializer in a CONSTRUCTOR so that build_vec_init recognizes it as direct-initialization. */ init = build_constructor_single (init_list_type_node, NULL_TREE, init); CONSTRUCTOR_IS_DIRECT_INIT (init) = true; so I propose to do the same in build_vec_init. PR c++/102594 gcc/cp/ChangeLog: * init.cc (build_vec_init): Build up a CONSTRUCTOR to signal direct-initialization rather than a TREE_LIST. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/decomp61.C: New test. Reviewed-by: Jason Merrill <ja...@redhat.com>
