https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96553
Bug ID: 96553 Summary: ICE in unexpected expression ‘__alignof__ (auto:1)’ of kind alignof_expr Product: gcc Version: 11.0 Status: UNCONFIRMED Keywords: error-recovery, ice-on-invalid-code Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: haoxintu at gmail dot com Target Milestone: --- Hi, all. This code, reduced by C-Vise, makes GCC-trunk ICE and released versions "confused by earlier errors, bailing out". Input: //small.cc class Test{ Test &operator || ( alignas (auto) enum{}); }; Command: g++ small.cc Output: small.cc:2:34: warning: use of ‘auto’ in parameter declaration only available with ‘-fconcepts-ts’ 2 | Test &operator || ( alignas (auto) enum{}); | ^~~~ small.cc:2:40: error: types may not be defined in parameter types 2 | Test &operator || ( alignas (auto) enum{}); | ^~~~ small.cc:2:45: internal compiler error: unexpected expression ‘__alignof__ (auto:1)’ of kind alignof_expr 2 | Test &operator || ( alignas (auto) enum{}); | ^ 0x8e014c cxx_eval_constant_expression ../../gcc/cp/constexpr.c:6567 0x8e068f cxx_eval_outermost_constant_expr ../../gcc/cp/constexpr.c:6772 0x8e4aab maybe_constant_value(tree_node*, tree_node*, bool) ../../gcc/cp/constexpr.c:7045 0x95075b cp_check_const_attributes(tree_node*) ../../gcc/cp/decl2.c:1428 0x955b72 cp_check_const_attributes(tree_node*) ../../gcc/cp/decl2.c:1416 0x955b72 cplus_decl_attributes(tree_node**, tree_node*, int) ../../gcc/cp/decl2.c:1584 0x9f27a4 cp_parser_parameter_declaration_list ../../gcc/cp/parser.c:22725 0x9f2b21 cp_parser_parameter_declaration_clause ../../gcc/cp/parser.c:22622 0x9df4f1 cp_parser_direct_declarator ../../gcc/cp/parser.c:21299 0x9df4f1 cp_parser_declarator ../../gcc/cp/parser.c:21163 0x9df045 cp_parser_declarator ../../gcc/cp/parser.c:21141 0x9fe4ce cp_parser_member_declaration ../../gcc/cp/parser.c:25291 0x9d0ea8 cp_parser_member_specification_opt ../../gcc/cp/parser.c:24904 0x9d0ea8 cp_parser_class_specifier_1 ../../gcc/cp/parser.c:24001 0x9d3143 cp_parser_class_specifier ../../gcc/cp/parser.c:24308 0x9d3143 cp_parser_type_specifier ../../gcc/cp/parser.c:17811 0x9d40be cp_parser_decl_specifier_seq ../../gcc/cp/parser.c:14436 0x9d4e71 cp_parser_simple_declaration ../../gcc/cp/parser.c:13690 0xa002fe cp_parser_declaration ../../gcc/cp/parser.c:13510 0xa009db cp_parser_translation_unit ../../gcc/cp/parser.c:4793 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. My GCC version is updated on 2020-08-08. Thanks, Haoxin