http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60217
Bug ID: 60217 Summary: Numerous ICEs involving wrong usage of __bases Product: gcc Version: 4.9.0 Status: UNCONFIRMED Keywords: ice-on-invalid-code Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: reichelt at gcc dot gnu.org One note up front: The testcases below involving __bases can be compiled in C++98 mode. But, since __bases yields a parameter pack, shouldn't its use only be allowed in C++11 mode - or at least trigger a warning in C++98 mode? The following invalid code snippet triggers an ICE since GCC 4.7.0 (when __bases was introduced): ================================== template<typename> struct A { typedef A<__bases(int)> B; }; ================================== bug.cc:3:25: internal compiler error: tree check: expected tree that contains 'typed' structure, have 'bases' in any_template_arguments_need_structural_equality_p, at cp/pt.c:20994 typedef A<__bases(int)> B; ^ 0xdc0f94 tree_contains_struct_check_failed(tree_node const*, tree_node_structure_enum, char const*, int, char const*) ../../gcc/gcc/tree.c:9364 0x626497 contains_struct_check ../../gcc/gcc/tree.h:2823 0x626497 any_template_arguments_need_structural_equality_p ../../gcc/gcc/cp/pt.c:20994 0x626497 lookup_template_class_1 ../../gcc/gcc/cp/pt.c:7553 0x626497 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*, int, int) ../../gcc/gcc/cp/pt.c:7725 0x72dcb2 finish_template_type(tree_node*, tree_node*, int) ../../gcc/gcc/cp/semantics.c:2953 0x6c2068 cp_parser_template_id ../../gcc/gcc/cp/parser.c:13440 0x6c2388 cp_parser_class_name ../../gcc/gcc/cp/parser.c:19074 0x6b3bb9 cp_parser_qualifying_entity ../../gcc/gcc/cp/parser.c:5524 0x6b3bb9 cp_parser_nested_name_specifier_opt ../../gcc/gcc/cp/parser.c:5249 0x6cba67 cp_parser_simple_type_specifier ../../gcc/gcc/cp/parser.c:14638 0x6a948d cp_parser_type_specifier ../../gcc/gcc/cp/parser.c:14380 0x6c2ba0 cp_parser_decl_specifier_seq ../../gcc/gcc/cp/parser.c:11547 0x6a5fb3 cp_parser_member_declaration ../../gcc/gcc/cp/parser.c:20121 0x6a9724 cp_parser_member_specification_opt ../../gcc/gcc/cp/parser.c:19976 0x6a9724 cp_parser_class_specifier_1 ../../gcc/gcc/cp/parser.c:19210 0x6a9724 cp_parser_class_specifier ../../gcc/gcc/cp/parser.c:19437 0x6a9724 cp_parser_type_specifier ../../gcc/gcc/cp/parser.c:14302 0x6c2ba0 cp_parser_decl_specifier_seq ../../gcc/gcc/cp/parser.c:11547 0x6c8883 cp_parser_single_declaration ../../gcc/gcc/cp/parser.c:23039 Please submit a full bug report, [etc.] With an even shorter testcase one can trigger a different ICE: ================================== template<typename> struct A { typedef __bases(int) B; }; ================================== bug.cc:3:24: internal compiler error: tree check: expected tree that contains 'common' structure, have 'bases' in set_underlying_type, at c-family/c-common.c:11445 typedef __bases(int) B; ^ 0xdc0f94 tree_contains_struct_check_failed(tree_node const*, tree_node_structure_enum, char const*, int, char const*) ../../gcc/gcc/tree.c:9364 0x7e1c54 contains_struct_check ../../gcc/gcc/tree.h:2823 0x7e1c54 set_underlying_type(tree_node*) ../../gcc/gcc/c-family/c-common.c:11445 0x686426 grokfield(cp_declarator const*, cp_decl_specifier_seq*, tree_node*, bool, tree_node*, tree_node*) ../../gcc/gcc/cp/decl2.c:898 0x6a611f cp_parser_member_declaration ../../gcc/gcc/cp/parser.c:20429 0x6a9724 cp_parser_member_specification_opt ../../gcc/gcc/cp/parser.c:19976 0x6a9724 cp_parser_class_specifier_1 ../../gcc/gcc/cp/parser.c:19210 0x6a9724 cp_parser_class_specifier ../../gcc/gcc/cp/parser.c:19437 0x6a9724 cp_parser_type_specifier ../../gcc/gcc/cp/parser.c:14302 0x6c2ba0 cp_parser_decl_specifier_seq ../../gcc/gcc/cp/parser.c:11547 0x6c8883 cp_parser_single_declaration ../../gcc/gcc/cp/parser.c:23039 0x6c8d64 cp_parser_template_declaration_after_export ../../gcc/gcc/cp/parser.c:22915 0x6d4119 cp_parser_declaration ../../gcc/gcc/cp/parser.c:10947 0x6d2c08 cp_parser_declaration_seq_opt ../../gcc/gcc/cp/parser.c:10869 0x6d44aa cp_parser_translation_unit ../../gcc/gcc/cp/parser.c:4014 0x6d44aa c_parse_file() ../../gcc/gcc/cp/parser.c:31536 0x7f3813 c_common_parse_file() ../../gcc/gcc/c-family/c-opts.c:1060 Please submit a full bug report, [etc.] The last testcase only crashes trunk: ================================== template<typename> struct A { typedef A<__bases(int) = int> B; }; ================================== bug.cc:3:24: internal compiler error: tree check: expected tree that contains 'typed' structure, have 'bases' in build_functional_cast, at cp/typeck2.c:1787 typedef A<__bases(int) = int> B; ^ 0xdc0f94 tree_contains_struct_check_failed(tree_node const*, tree_node_structure_enum, char const*, int, char const*) ../../gcc/gcc/tree.c:9364 0x653589 contains_struct_check ../../gcc/gcc/tree.h:2823 0x653589 build_functional_cast(tree_node*, tree_node*, int) ../../gcc/gcc/cp/typeck2.c:1787 0x6b8559 cp_parser_functional_cast ../../gcc/gcc/cp/parser.c:23195 0x6b20fa cp_parser_postfix_expression ../../gcc/gcc/cp/parser.c:5884 0x6b5116 cp_parser_unary_expression ../../gcc/gcc/cp/parser.c:7170 0x6b5e3f cp_parser_binary_expression ../../gcc/gcc/cp/parser.c:7874 0x6b6331 cp_parser_assignment_expression ../../gcc/gcc/cp/parser.c:8112 0x6b6793 cp_parser_assignment_expression ../../gcc/gcc/cp/parser.c:8162 0x6b6793 cp_parser_constant_expression ../../gcc/gcc/cp/parser.c:8372 0x6c0d30 cp_parser_template_argument ../../gcc/gcc/cp/parser.c:13998 0x6c0d30 cp_parser_template_argument_list ../../gcc/gcc/cp/parser.c:13721 0x6c0d30 cp_parser_enclosed_template_argument_list ../../gcc/gcc/cp/parser.c:23330 0x6c1d22 cp_parser_template_id ../../gcc/gcc/cp/parser.c:13419 0x6c2388 cp_parser_class_name ../../gcc/gcc/cp/parser.c:19074 0x6b3bb9 cp_parser_qualifying_entity ../../gcc/gcc/cp/parser.c:5524 0x6b3bb9 cp_parser_nested_name_specifier_opt ../../gcc/gcc/cp/parser.c:5249 0x6cba67 cp_parser_simple_type_specifier ../../gcc/gcc/cp/parser.c:14638 0x6a948d cp_parser_type_specifier ../../gcc/gcc/cp/parser.c:14380 0x6c2ba0 cp_parser_decl_specifier_seq ../../gcc/gcc/cp/parser.c:11547 Please submit a full bug report, [etc.]