https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94938
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:e5613c55c2900cd23c9e78592f10258e19c74ab3 commit r10-8120-ge5613c55c2900cd23c9e78592f10258e19c74ab3 Author: Marek Polacek <pola...@redhat.com> Date: Thu May 7 14:34:15 2020 -0400 c++: ICE in value_dependent_expression_p in C++98 mode [PR94938] Here we ICE with -std=c++98 since the newly added call to uses_template_parms (r10-6357): we hit 26530 gcc_assert (cxx_dialect >= cxx11 26531 || INTEGRAL_OR_ENUMERATION_TYPE_P (type)); and TYPE is a record type. The problem is that the argument to value_dependent_expression_p does not satisfy potential_constant_expression which it must, as the comment explains. I thought about fixing this in uses_template_parms -- only call v_d_e_p if p_c_e is true, but in this case we want to also suppress the warnings if we don't have a constant expression. I couldn't simply check TREE_CONSTANT as in compute_array_index_type_loc, because then we'd stop warning in the new Wtype-limits3.C test. Fixed by using type_dependent_expression_p_push instead. This means that we won't suppress the warnings for value-dependent expressions that aren't type-dependent, e.g. sizeof (T). This only seems to make a difference for -Wdiv-by-zero, now tested in Wdiv-by-zero-3.C, where I think it's reasonable to warn. It could make -Wtautological-compare warn more, but that warning doesn't trigger when it gets constant arguments. Wtype-limits4.C is a test reduced from poly-int.h and it tests a scenario that was missing in our testsuite. This patch also moves the warning_sentinels after the RECURs -- we mean to use them for build_x_binary_op purposes only. PR c++/94938 * pt.c (tsubst_copy_and_build): Call type_dependent_expression_p_push instead of uses_template_parms. Move the warning_sentinels after the RECURs. * g++.dg/warn/Wdiv-by-zero-3.C: New test. * g++.dg/warn/Wtype-limits4.C: New test. * g++.dg/warn/template-2.C: New test. * g++.old-deja/g++.pt/crash10.C: Add dg-warning.
