With a 13.2 based package, on SLE-11 using gcc 4.3.4, I run into: ... (gdb) FAIL: gdb.objc/basicclass.exp: breakpoint in category method continue Continuing. Breakpoint 5, -[BasicClass(Private) hiddenMethod] (self=0x605170, _cmd=0x601400 <_OBJC_SELECTOR_TABLE+32>) at /usr/src/packages/BUILD/gdb-13.2/gdb/testsuite/gdb.objc/basicclass.m:62 62 return self; (gdb) FAIL: gdb.objc/basicclass.exp: continue until category method print [self printHi] Fatal signal: Segmentation fault ----- Backtrace ----- 0x4fffc2 gdb_internal_backtrace_1 ../../gdb/bt-utils.c:122 0x4fffc2 _Z22gdb_internal_backtracev ../../gdb/bt-utils.c:168 0x6146d7 handle_fatal_signal ../../gdb/event-top.c:971 0x61475f handle_sigsegv ../../gdb/event-top.c:1044 0x151a6dc0f84f ??? 0x8f2860 _Z10value_typePK5value ../../gdb/value.c:1111 0x683270 value_arg_coerce ../../gdb/infcall.c:184 0x683270 _Z27call_function_by_hand_dummyP5valueP4typeN3gdb10array_viewIS0_EEPFvPviES6_ ../../gdb/infcall.c:1112 0x685c5e _Z21call_function_by_handP5valueP4typeN3gdb10array_viewIS0_EE ../../gdb/infcall.c:786 0x60e290 eval_op_objc_msgcall ../../gdb/eval.c:2176 0x60e290 _ZN4expr22objc_msgcall_operation8evaluateEP4typeP10expression6noside ../../gdb/eval.c:2253 0x61288e _ZN10expression8evaluateEP4type6noside ../../gdb/eval.c:101 0x77c8fc process_print_command_args ../../gdb/printcmd.c:1310 0x77d2cd print_command_1 ../../gdb/printcmd.c:1323 0x533125 _Z8cmd_funcP16cmd_list_elementPKci ../../gdb/cli/cli-decode.c:2543 0x8a24a6 _Z15execute_commandPKci ../../gdb/top.c:690 0x615403 _Z15command_handlerPKc ../../gdb/event-top.c:628 0x6163cd _Z20command_line_handlerOSt10unique_ptrIcN3gdb13xfree_deleterIcEEE ../../gdb/event-top.c:864 0x61498b gdb_rl_callback_handler ../../gdb/event-top.c:256 0x92085f rl_callback_read_char ../../../readline/readline/callback.c:290 0x614b9d gdb_rl_callback_read_char_wrapper_noexcept ../../gdb/event-top.c:192 0x614d6f gdb_rl_callback_read_char_wrapper ../../gdb/event-top.c:231 0x6147ff stdin_event_handler ../../gdb/event-top.c:553 0xac559c gdb_wait_for_event ../../gdbsupport/event-loop.cc:694 0xac5d31 _Z16gdb_do_one_eventi ../../gdbsupport/event-loop.cc:264 0x6f26f9 start_event_loop ../../gdb/main.c:411 0x6f26f9 captured_command_loop ../../gdb/main.c:471 0x6f3f04 captured_main ../../gdb/main.c:1330 0x6f3f04 _Z8gdb_mainP18captured_main_args ../../gdb/main.c:1345 0x414c84 main ../../gdb/gdb.c:32 --------------------- A fatal error internal to GDB has been detected, further debugging is not possible. GDB will now terminate. This is a bug, please report it. For instructions, see: <http://bugs.opensuse.org/>. ...
In more detail: ... Breakpoint 5, -[BasicClass(Private) hiddenMethod] (self=0x605170, _cmd=0x601400 <_OBJC_SELECTOR_TABLE+32>) at /usr/src/packages/BUILD/gdb-13.2/build-x86_64-suse-linux/gdb/testsuite/../../../gdb/testsuite/gdb.objc/basicclass.m:62 62 return self; Thread 1 "gdb" received signal SIGSEGV, Segmentation fault. value_type (value=value@entry=0x0) at ../../gdb/value.c:1111 1111 return value->type; (gdb) bt #0 value_type (value=value@entry=0x0) at ../../gdb/value.c:1111 #1 0x0000000000683271 in value_arg_coerce (is_prototyped=0, param_type=<optimized out>, arg=0x0, gdbarch=0x7ffff017c0d0) at ../../gdb/infcall.c:184 #2 call_function_by_hand_dummy (function=function@entry=0x7ffff026bf50, default_return_type=default_return_type@entry=0x0, args=..., dummy_dtor=dummy_dtor@entry=0x0, dummy_dtor_data=dummy_dtor_data@entry=0x0) at ../../gdb/infcall.c:1112 #3 0x0000000000685c5f in call_function_by_hand (function=function@entry=0x7ffff026bf50, default_return_type=default_return_type@entry=0x0, args=...) at ../../gdb/infcall.c:786 #4 0x000000000060e291 in eval_op_objc_msgcall (exp=<optimized out>, args=..., target=0x7ffff02563c0, selector=6304368, noside=EVAL_NORMAL, expect_type=0x0) at ../../gdb/eval.c:2176 #5 expr::objc_msgcall_operation::evaluate (this=<optimized out>, expect_type=0x0, exp=<optimized out>, noside=EVAL_NORMAL) at ../../gdb/eval.c:2253 #6 0x000000000061288f in expression::evaluate (this=0x7ffff01aca60, expect_type=expect_type@entry=0x0, noside=noside@entry=EVAL_NORMAL) at ../../gdb/eval.c:101 #7 0x0000000000612a67 in evaluate_expression (exp=<optimized out>, expect_type=expect_type@entry=0x0) at ../../gdb/eval.c:115 #8 0x000000000077c8fd in process_print_command_args (args=0x7ffff01d93ce "[self printHi]", print_opts=print_opts@entry=0x7fffffffdeb0, voidprint=voidprint@entry=true) at ../../gdb/printcmd.c:1310 #9 0x000000000077d2ce in print_command_1 (args=<optimized out>, voidprint=<optimized out>) at ../../gdb/printcmd.c:1323 #10 0x0000000000533126 in cmd_func (cmd=<optimized out>, args=<optimized out>, from_tty=<optimized out>) at ../../gdb/cli/cli-decode.c:2543 #11 0x00000000008a24a7 in execute_command (p=<optimized out>, p@entry=0x7ffff01d93c8 "print [self printHi]", from_tty=0) at ../../gdb/top.c:690 #12 0x0000000000615404 in command_handler (command=0x7ffff01d93c8 "print [self printHi]") at ../../gdb/event-top.c:628 #13 0x000000000089fcec in read_command_file (stream=stream@entry=0x7ffff0127320) at ../../gdb/top.c:457 #14 0x000000000054228e in script_from_file (stream=stream@entry=0x7ffff0127320, file=file@entry=0x7fffffffe8d5 "outputs/gdb.objc/basicclass/gdb.in.1") at ../../gdb/cli/cli-script.c:1641 #15 0x0000000000530294 in source_script_from_stream ( file_to_open=0x7ffff0080c48 "outputs/gdb.objc/basicclass/gdb.in.1", file=0x7fffffffe8d5 "outputs/gdb.objc/basicclass/gdb.in.1", stream=0x7ffff0127320) at ../../gdb/cli/cli-cmds.c:729 #16 source_script_with_search (file=0x7fffffffe8d5 "outputs/gdb.objc/basicclass/gdb.in.1", file@entry=<error reading variable: value has been optimized out>, from_tty=<error reading variable: value has been optimized out>, search_path=<error reading variable: value has been optimized out>) at ../../gdb/cli/cli-cmds.c:774 #17 0x00000000006f1d24 in catch_command_errors (command=<optimized out>, arg=<optimized out>, from_tty=<optimized out>, do_bp_actions=do_bp_actions@entry=false) at ../../gdb/main.c:513 #18 0x00000000006f1df6 in execute_cmdargs (cmdarg_vec=cmdarg_vec@entry=0x7fffffffe2d0, file_type=file_type@entry=CMDARG_FILE, cmd_type=cmd_type@entry=CMDARG_COMMAND, ret=ret@entry=0x7fffffffe26c) at ../../gdb/main.c:606 #19 0x00000000006f2ffa in captured_main_1 (context=context@entry=0x7fffffffe420) at ../../gdb/main.c:1299 #20 0x00000000006f3efb in captured_main (data=data@entry=0x7fffffffe420) at ../../gdb/main.c:1320 #21 gdb_main (args=args@entry=0x7fffffffe440) at ../../gdb/main.c:1345 #22 0x0000000000414c85 in main (argc=<optimized out>, argv=<optimized out>) at ../../gdb/gdb.c:32 ...
Commit [1] changed the arrayview argument of the last 2 call_function_by_hand calls to include the NULL pointer at the end, I suspect this is the reason for the crash. It also added the following comment to the split out function: > /* Note that ARGS needs 2 empty slots up front and must end with a > null pointer. */ Why is this null pointer even needed? [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=5e80600ed0e929faaeac205dbf0d4e7f9b2842cb
(In reply to Hannes Domani from comment #2) > Why is this null pointer even needed? It probably isn't; but before it took an array_view, maybe call_function_by_hand required a NULL-terminated array.
I can't seem to run this test: UNSUPPORTED: gdb.objc/basicclass.exp: couldn't compile basicclass.m: unrecognized error My recollection is that some change to the objective-c runtime made all the gdb.objc tests stop compiling, and nobody has ever gone back and tried to fix them.