https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97328
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:3d423c6f6a69d87ad52ba3af75f3debd8a8b8810 commit r11-4231-g3d423c6f6a69d87ad52ba3af75f3debd8a8b8810 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Oct 22 07:40:40 2020 -0400 c++: Handle RANGE_EXPR index in init_subob_ctx [PR97328] In the testcase below, we're ICEing during constexpr evaluation of the CONSTRUCTOR {.data={{}, [1 ... 7]={}}} of type 'vector'. The interesting thing about this CONSTRUCTOR is that it has a RANGE_EXPR index for an element initializer which doesn't satisfy reduced_constant_expression_p (because the field 't' is uninitialized). This is a problem because init_subob_ctx currently punts on setting up a sub-aggregate initialization context when given a RANGE_EXPR index, so we later trip over the asserts in verify_ctor_sanity when recursing into cxx_eval_bare_aggregate on this element initializer. Fix this by making init_subob_ctx set up an appropriate initialization context when supplied a RANGE_EXPR index. gcc/cp/ChangeLog: PR c++/97328 * constexpr.c (init_subob_ctx): Don't punt on RANGE_EXPR indexes, instead build a sub-aggregate initialization context with no subobject. gcc/testsuite/ChangeLog: PR c++/97328 * g++.dg/cpp2a/constexpr-init19.C: New test. * g++.dg/cpp2a/constexpr-init20.C: New test.