https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90047
--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> --- Author: jason Date: Thu Apr 18 03:32:24 2019 New Revision: 270433 URL: https://gcc.gnu.org/viewcvs?rev=270433&root=gcc&view=rev Log: PR c++/90047 - ICE with enable_if alias template. In order to make alias templates useful for SFINAE we instantiate them under the prevailing 'complain' argument, so an error encountered while instantiating during SFINAE context is silent. The problem in this PR comes when we later look up the erroneous instantiation and don't give an error at that point. Fixed by not adding an erroneous instantiation to the hash table, so we instantiate it again when needed and get the error. This required changes to a number of tests, which previously said "substitution failed:" with no explanation of what the failure was; now we properly explain. * pt.c (tsubst_decl) [TYPE_DECL]: Don't put an erroneous decl in the hash table when we're in SFINAE context. Added: trunk/gcc/testsuite/g++.dg/cpp0x/alias-decl-67.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/pt.c trunk/gcc/testsuite/g++.old-deja/g++.robertl/eb43.C trunk/libstdc++-v3/testsuite/20_util/duration/arithmetic/dr3050.cc trunk/libstdc++-v3/testsuite/20_util/from_chars/1_c++20_neg.cc trunk/libstdc++-v3/testsuite/20_util/from_chars/1_neg.cc trunk/libstdc++-v3/testsuite/20_util/shared_ptr/assign/auto_ptr_neg.cc trunk/libstdc++-v3/testsuite/20_util/shared_ptr/assign/shared_ptr_neg.cc trunk/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_neg.cc trunk/libstdc++-v3/testsuite/20_util/to_chars/1_neg.cc trunk/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc trunk/libstdc++-v3/testsuite/20_util/unique_ptr/cons/ptr_deleter_neg.cc trunk/libstdc++-v3/testsuite/20_util/unique_ptr/modifiers/reset_neg.cc trunk/libstdc++-v3/testsuite/23_containers/deque/requirements/dr438/assign_neg.cc trunk/libstdc++-v3/testsuite/23_containers/deque/requirements/dr438/constructor_1_neg.cc trunk/libstdc++-v3/testsuite/23_containers/deque/requirements/dr438/constructor_2_neg.cc trunk/libstdc++-v3/testsuite/23_containers/deque/requirements/dr438/insert_neg.cc trunk/libstdc++-v3/testsuite/23_containers/forward_list/requirements/dr438/assign_neg.cc trunk/libstdc++-v3/testsuite/23_containers/forward_list/requirements/dr438/constructor_1_neg.cc trunk/libstdc++-v3/testsuite/23_containers/forward_list/requirements/dr438/constructor_2_neg.cc trunk/libstdc++-v3/testsuite/23_containers/forward_list/requirements/dr438/insert_neg.cc trunk/libstdc++-v3/testsuite/23_containers/list/requirements/dr438/assign_neg.cc trunk/libstdc++-v3/testsuite/23_containers/list/requirements/dr438/constructor_1_neg.cc trunk/libstdc++-v3/testsuite/23_containers/list/requirements/dr438/constructor_2_neg.cc trunk/libstdc++-v3/testsuite/23_containers/list/requirements/dr438/insert_neg.cc trunk/libstdc++-v3/testsuite/23_containers/vector/requirements/dr438/assign_neg.cc trunk/libstdc++-v3/testsuite/23_containers/vector/requirements/dr438/constructor_1_neg.cc trunk/libstdc++-v3/testsuite/23_containers/vector/requirements/dr438/constructor_2_neg.cc trunk/libstdc++-v3/testsuite/23_containers/vector/requirements/dr438/insert_neg.cc trunk/libstdc++-v3/testsuite/experimental/memory/shared_ptr/cons/copy_ctor_neg.cc trunk/libstdc++-v3/testsuite/experimental/memory/shared_ptr/cons/pointer_ctor_neg.cc trunk/libstdc++-v3/testsuite/experimental/memory/shared_ptr/modifiers/reset_neg.cc
