https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120766
Bug ID: 120766 Summary: ICE Segmentation fault with duplicate extern variable of template type Product: gcc Version: 16.0 Status: UNCONFIRMED Keywords: ice-on-valid-code Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: rush102333 at gmail dot com Target Milestone: --- Probably starts from gcc-12: https://godbolt.org/z/acEsfbn3j Simplified Test: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ template<typename _Tp, typename _Bt = _Tp> class RepPtrStore { _Tp * _obj; void foo(); }; template<typename _Tp,typename _Bt> void RepPtrStore<_Tp,_Bt>::foo() { extern _Tp * new_r; extern _Tp * new_r; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Stack Dump: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ <source>: In member function 'void RepPtrStore<_Tp, _Bt>::foo()': <source>:10:18: internal compiler error: Segmentation fault 10 | extern _Tp * new_r; | ^~~~~ 0x283a3d5 diagnostic_context::diagnostic_impl(rich_location*, diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag (*) [1], diagnostic_t) ???:0 0x285bb66 internal_error(char const*, ...) ???:0 0xdf3f3f merge_decl_attributes(tree_node*, tree_node*) ???:0 0xbbd06f duplicate_decls(tree_node*, tree_node*, bool, bool) ???:0 0xc9836f pushdecl(tree_node*, bool) ???:0 0xbcbd9d start_decl(cp_declarator const*, cp_decl_specifier_seq*, int, tree_node*, tree_node*, tree_node**) ???:0 0xd07833 c_parse_file() ???:0 0xe6f319 c_common_parse_file() ???:0 Please submit a full bug report, with preprocessed source (by using -freport-bug). Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~