https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107593
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:07ef737cf1ab08f5c36786c7ab1ffc596fe52138 commit r12-9093-g07ef737cf1ab08f5c36786c7ab1ffc596fe52138 Author: Marek Polacek <pola...@redhat.com> Date: Tue Jan 31 11:54:03 2023 -0500 c++: fix ICE with -Wduplicated-cond [PR107593] Here we crash because a CAST_EXPR, representing T(), doesn't have its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't expect that. (o_e_p is called from warn_duplicated_cond_add_or_warn.) In the past we've adjusted o_e_p to better cope with template codes, but in this case I think we just want to avoid attempting to warn about inst-dependent expressions; I don't think I've ever envisioned -Wduplicated-cond to warn about them. Also destroy the chain when an inst-dependent expression is encountered to not warn in Wduplicated-cond4.C. The ICE started with r12-6022, two-stage name lookup for overloaded operators, which gave dependent operators a TREE_TYPE (in particular, DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p: /* Similar, if either does not have a type (like a template id), they aren't equal. */ if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1)) return false; PR c++/107593 PR c++/108597 gcc/c-family/ChangeLog: * c-common.h (instantiation_dependent_expression_p): Declare. * c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition is dependent, invalidate the chain. gcc/c/ChangeLog: * c-objc-common.cc (instantiation_dependent_expression_p): New. gcc/cp/ChangeLog: * cp-tree.h (instantiation_dependent_expression_p): Don't declare here. gcc/testsuite/ChangeLog: * g++.dg/warn/Wduplicated-cond3.C: New test. * g++.dg/warn/Wduplicated-cond4.C: New test. * g++.dg/warn/Wduplicated-cond5.C: New test.
