https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100344
--- Comment #11 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:eef4fa6968ae0682679c27dae06409db3d113d5d commit r12-391-geef4fa6968ae0682679c27dae06409db3d113d5d Author: Patrick Palka <ppa...@redhat.com> Date: Mon May 3 13:35:26 2021 -0400 c++: mark_used and ADL with template-id [PR100344] My r11-295 patch for PR68942 didn't consider that the callee of an ADL-eligible function call can be a TEMPLATE_ID_EXPR, and we don't want to disable mark_used when substituting into the template arguments of this TEMPLATE_ID_EXPR because the arguments are clearly used regardless of the outcome of ADL. In the first testcase below, this oversight causes us to trip over the assert in build_call_a for the call to find_index<int> because the function no longer had its TREE_USED bit set from mark_used. So this patch restricts the original fix to disable mark_used only when the callee is a FUNCTION_DECL, which seems to be the only case that matters for PR68942. For instance, in the second testcase below we already don't mark_used the deleted function specialization even before r11-295. gcc/cp/ChangeLog: PR c++/68942 PR c++/100344 * pt.c (tsubst_copy_and_build) <case CALL_EXPR>: Set tf_conv only when the callee is a FUNCTION_DECL. gcc/testsuite/ChangeLog: PR c++/68942 PR c++/100344 * g++.dg/template/call8.C: New test. * g++.dg/template/koenig12a.C: New test.
