https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89933
Bug ID: 89933 Summary: [7/8/9 Regression] ICE in merge_decls, at c/c-decl.c:2517 Product: gcc Version: 9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: gs...@t-online.de Target Milestone: --- Doubled line affects versions 7 up to trunk. gcc-6 rejects it with an error. clang7 and icc19 accepts it without any warning/error. $ cat z1.c typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__)); typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__)); $ gcc-9-20190331 -c z1.c z1.c:2:1: internal compiler error: Segmentation fault 2 | typedef unsigned int a __attribute__ ((__aligned__(8), __may_alias__)); | ^~~~~~~ 0xa748df crash_signal ../../gcc/toplev.c:326 0x5c9023 merge_decls ../../gcc/c/c-decl.c:2517 0x5c9023 duplicate_decls ../../gcc/c/c-decl.c:2886 0x5cb067 pushdecl(tree_node*) ../../gcc/c/c-decl.c:3072 0x5db56d start_decl(c_declarator*, c_declspecs*, bool, tree_node*) ../../gcc/c/c-decl.c:5016 0x61d983 c_parser_declaration_or_fndef ../../gcc/c/c-parser.c:2154 0x623a53 c_parser_external_declaration ../../gcc/c/c-parser.c:1653 0x624519 c_parser_translation_unit ../../gcc/c/c-parser.c:1534 0x624519 c_parse_file() ../../gcc/c/c-parser.c:19854 0x66ba20 c_common_parse_file() ../../gcc/c-family/c-opts.c:1156