https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92206
--- Comment #10 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Wed Nov 13 08:42:56 2019 New Revision: 278119 URL: https://gcc.gnu.org/viewcvs?rev=278119&root=gcc&view=rev Log: [C++] Fix interaction between aka changes and DR1558 (PR92206) One of the changes in r277281 was to make the typedef variant handling in strip_typedefs pass the raw DECL_ORIGINAL_TYPE to the recursive call, instead of applying TYPE_MAIN_VARIANT first. This PR shows that that interacts badly with the implementation of DR1558, because we then refuse to strip aliases with dependent template parameters and trip: gcc_assert (!typedef_variant_p (result) || ((flags & STF_USER_VISIBLE) && !user_facing_original_type_p (result))); Keeping the current behaviour but suppressing the ICE leads to a duplicate error (the dg-bogus in the first test), so that didn't seem like a good fix. I assume keeping the alias should never actually be necessary for DECL_ORIGINAL_TYPEs, because it will already have been checked somewhere, even for implicit TYPE_DECLs. This patch therefore passes a flag to say that we can safely strip aliases with dependent template parameters. 2019-11-13 Richard Sandiford <richard.sandif...@arm.com> gcc/cp/ PR c++/92206 * cp-tree.h (STF_STRIP_DEPENDENT): New constant. * tree.c (strip_typedefs): Add STF_STRIP_DEPENDENT to the flags when calling strip_typedefs recursively on a DECL_ORIGINAL_TYPE. Don't apply the fix for DR1558 in that case; allow aliases with dependent template parameters to be stripped instead. gcc/testsuite/ PR c++/92206 * g++.dg/cpp0x/alias-decl-pr92206-1.C: New test. * g++.dg/cpp0x/alias-decl-pr92206-2.C: Likewise. * g++.dg/cpp0x/alias-decl-pr92206-3.C: Likewise. Added: trunk/gcc/testsuite/g++.dg/cpp0x/alias-decl-pr92206-1.C trunk/gcc/testsuite/g++.dg/cpp0x/alias-decl-pr92206-2.C trunk/gcc/testsuite/g++.dg/cpp0x/alias-decl-pr92206-3.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-tree.h trunk/gcc/cp/tree.c trunk/gcc/testsuite/ChangeLog
