http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60374
Bug ID: 60374 Summary: [4.7/4.8/4.9 Regression] ICE with invalid template specialization Product: gcc Version: 4.9.0 Status: UNCONFIRMED Keywords: error-recovery, ice-on-invalid-code Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: reichelt at gcc dot gnu.org The following invalid testcase (compiled with "-std=c++11") triggers an ICE since GCC 4.7.0: =============================================== template<typename> struct A {}; template<typename...T> struct A<T::T...> {}; A<int> a; =============================================== bug.cc:3:31: error: template argument 'T:: T' involves template parameter(s) template<typename...T> struct A<T::T...> {}; ^ bug.cc:5:8: internal compiler error: in unify_one_argument, at cp/pt.c:16311 A<int> a; ^ 0x63a5ec unify_one_argument ../../gcc/gcc/cp/pt.c:16310 0x63b430 unify_pack_expansion ../../gcc/gcc/cp/pt.c:17129 0x6389de unify ../../gcc/gcc/cp/pt.c:17884 0x63e6ff get_class_bindings ../../gcc/gcc/cp/pt.c:18610 0x63f37e most_specialized_class ../../gcc/gcc/cp/pt.c:18852 0x64ecf9 instantiate_class_template_1 ../../gcc/gcc/cp/pt.c:8867 0x64ecf9 instantiate_class_template(tree_node*) ../../gcc/gcc/cp/pt.c:9399 0x6e1d83 complete_type(tree_node*) ../../gcc/gcc/cp/typeck.c:134 0x5c8e58 start_decl_1(tree_node*, bool) ../../gcc/gcc/cp/decl.c:4719 0x5f1ef7 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int, tree_node*, tree_node*, tree_node**) ../../gcc/gcc/cp/decl.c:4682 0x6ce2be cp_parser_init_declarator ../../gcc/gcc/cp/parser.c:16684 0x6cfd49 cp_parser_simple_declaration ../../gcc/gcc/cp/parser.c:11205 0x6b3003 cp_parser_block_declaration ../../gcc/gcc/cp/parser.c:11086 0x6da2d2 cp_parser_declaration ../../gcc/gcc/cp/parser.c:10983 0x6d8fc8 cp_parser_declaration_seq_opt ../../gcc/gcc/cp/parser.c:10869 0x6da87a cp_parser_translation_unit ../../gcc/gcc/cp/parser.c:4014 0x6da87a c_parse_file() ../../gcc/gcc/cp/parser.c:31590 0x7f9fe3 c_common_parse_file() ../../gcc/gcc/c-family/c-opts.c:1060 Please submit a full bug report, [etc.]