http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59082
Bug ID: 59082 Summary: [4.7/4.8/4.9 Regression] ICE with duplicate (virtual) base Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: reichelt at gcc dot gnu.org The following invalid code snippet triggers an ICE since GCC 4.2.0: ================================ struct A {}; struct B : virtual A, A {}; A foo(const B &b) { return b; } ================================ bug.cc:3:23: error: duplicate base type 'A' invalid struct B : virtual A, A {}; ^ bug.cc: In function 'A foo(const B&)': bug.cc:7:10: internal compiler error: Segmentation fault return b; ^ 0xb2a93f crash_signal ../../gcc/gcc/toplev.c:334 0x618b2d contains_struct_check ../../gcc/gcc/tree.h:2819 0x618b2d build_vfield_ref(tree_node*, tree_node*) ../../gcc/gcc/cp/class.c:639 0x61816b build_base_path(tree_code, tree_node*, tree_node*, int, int) ../../gcc/gcc/cp/class.c:429 0x553a0c convert_like_real ../../gcc/gcc/cp/call.c:6108 0x552e1e convert_like_real ../../gcc/gcc/cp/call.c:6086 0x55491c build_over_call ../../gcc/gcc/cp/call.c:6944 0x550f3e build_new_method_call_1 ../../gcc/gcc/cp/call.c:7814 0x550f3e build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc, vl_embed>**, tree_node*, int, tree_node**, int) ../../gcc/gcc/cp/call.c:7884 0x551e87 build_special_member_call(tree_node*, tree_node*, vec<tree_node*, va_gc, vl_embed>**, tree_node*, int, int) ../../gcc/gcc/cp/call.c:7441 0x553223 build_temp ../../gcc/gcc/cp/call.c:5784 0x553223 convert_like_real ../../gcc/gcc/cp/call.c:6128 0x5576d9 perform_implicit_conversion_flags(tree_node*, tree_node*, int, int) ../../gcc/gcc/cp/call.c:9019 0x6853c3 check_return_expr(tree_node*, bool*) ../../gcc/gcc/cp/typeck.c:8538 0x6c4bde finish_return_stmt(tree_node*) ../../gcc/gcc/cp/semantics.c:798 0x64d726 cp_parser_jump_statement ../../gcc/gcc/cp/parser.c:10590 0x64d726 cp_parser_statement ../../gcc/gcc/cp/parser.c:9284 0x64dcb9 cp_parser_statement_seq_opt ../../gcc/gcc/cp/parser.c:9654 0x64de2e cp_parser_compound_statement ../../gcc/gcc/cp/parser.c:9608 0x6614cb cp_parser_function_body ../../gcc/gcc/cp/parser.c:18461 Please submit a full bug report, [etc.]