From 87e727c0c64e2a45ef48452884b2c07f3a79c516 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 11 May 2023 13:16:09 +0100 Subject: Windows gdb: Simplify windows_nat_target::wait The logic in windows_nat_target::wait, where we decide what to do depending on the result from get_windows_debug_event is harder to grasp than it looks. It is not easy to tell what should happen when in async mode get_windows_debug_event returns that there's no event to process. And then, if get_windows_debug_event returns null_ptid / TARGET_WAITKIND_SPURIOUS, then we need to issue a ContinueDebugEvent. There's also this comment in windows_nat_target::wait, which we're not really implementing today: ~~~~ /* We loop when we get a non-standard exception rather than return with a SPURIOUS because resume can try and step or modify things, which needs a current_thread->h. But some of these exceptions mark the birth or death of threads, which mean that the current thread isn't necessarily what you think it is. */ ~~~~ This patch changes things a bit so that the code is more obvious: - look at the status kind, instead of ptid_t. - add an explicit early return case for no-event. - add an explicit case for TARGET_WAITKIND_SPURIOUS. - with those, we no longer need to handle the case of find_thread not finding a thread, so we can drop one indentation level. Change-Id: I76c41762e1f893a7ff23465856ccf6a44af1f0e7 --- gdb/windows-nat.c | 41 +++++++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c index 9b1bede..9730377 100644 --- a/gdb/windows-nat.c +++ b/gdb/windows-nat.c @@ -1764,7 +1764,10 @@ windows_nat_target::get_windows_debug_event } if (thread_id == 0) - return null_ptid; + { + ourstatus->set_ignore (); + return null_ptid; + } return ptid_t (windows_process.current_event.dwProcessId, thread_id, 0); } @@ -1785,27 +1788,33 @@ windows_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus, { ptid_t result = get_windows_debug_event (pid, ourstatus, options); - if (result != null_ptid) + if ((options & TARGET_WNOHANG) != 0 + && ourstatus->kind () == TARGET_WAITKIND_IGNORE) + return result; + + if (ourstatus->kind () == TARGET_WAITKIND_SPURIOUS) + { + CHECK (windows_continue (DBG_CONTINUE, + windows_process.desired_stop_thread_id, 0)); + } + else if (ourstatus->kind () != TARGET_WAITKIND_IGNORE) { if (ourstatus->kind () != TARGET_WAITKIND_EXITED - && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) + && ourstatus->kind () != TARGET_WAITKIND_SIGNALLED) { windows_thread_info *th = windows_process.find_thread (result); - if (th != nullptr) + th->stopped_at_software_breakpoint = false; + if (windows_process.current_event.dwDebugEventCode + == EXCEPTION_DEBUG_EVENT + && ((windows_process.current_event.u.Exception.ExceptionRecord.ExceptionCode + == EXCEPTION_BREAKPOINT) + || (windows_process.current_event.u.Exception.ExceptionRecord.ExceptionCode + == STATUS_WX86_BREAKPOINT)) + && windows_process.windows_initialization_done) { - th->stopped_at_software_breakpoint = false; - if (windows_process.current_event.dwDebugEventCode - == EXCEPTION_DEBUG_EVENT - && ((windows_process.current_event.u.Exception.ExceptionRecord.ExceptionCode - == EXCEPTION_BREAKPOINT) - || (windows_process.current_event.u.Exception.ExceptionRecord.ExceptionCode - == STATUS_WX86_BREAKPOINT)) - && windows_process.windows_initialization_done) - { - th->stopped_at_software_breakpoint = true; - th->pc_adjusted = false; - } + th->stopped_at_software_breakpoint = true; + th->pc_adjusted = false; } } -- cgit v1.1