From e758e19c596f8d0683f6c8ca750eb4e79071523d Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 8 Apr 2020 14:33:35 -0600 Subject: [PATCH] Share some inferior-related Windows code This adds a couple of functions to nat/windows-nat.c and changes gdb and gdbserver to use them. One function checks the list of pending stops for a match (not yet used by gdbserver, but will be in a subsequent patch); and the other is a wrapper for ContinueDebugEvent that always uses the last "real" stop event. gdb/ChangeLog 2020-04-08 Tom Tromey * windows-nat.c (windows_continue): Use matching_pending_stop and continue_last_debug_event. * nat/windows-nat.h (matching_pending_stop) (continue_last_debug_event): Declare. * nat/windows-nat.c (DEBUG_EVENTS): New define. (matching_pending_stop, continue_last_debug_event): New functions. gdbserver/ChangeLog 2020-04-08 Tom Tromey * win32-low.c (child_continue): Call continue_last_debug_event. --- gdb/ChangeLog | 10 +++++++++ gdb/nat/windows-nat.c | 46 ++++++++++++++++++++++++++++++++++++++++++ gdb/nat/windows-nat.h | 13 ++++++++++++ gdb/windows-nat.c | 28 +++---------------------- gdbserver/ChangeLog | 4 ++++ gdbserver/win32-low.cc | 7 +------ 6 files changed, 77 insertions(+), 31 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 663e2af7dc..3929faf089 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2020-04-08 Tom Tromey + + * windows-nat.c (windows_continue): Use matching_pending_stop and + continue_last_debug_event. + * nat/windows-nat.h (matching_pending_stop) + (continue_last_debug_event): Declare. + * nat/windows-nat.c (DEBUG_EVENTS): New define. + (matching_pending_stop, continue_last_debug_event): New + functions. + 2020-04-08 Tom Tromey * windows-nat.c (MS_VC_EXCEPTION): Move to nat/windows-nat.c. diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c index 6bbf41c7b1..2c2454b6f6 100644 --- a/gdb/nat/windows-nat.c +++ b/gdb/nat/windows-nat.c @@ -37,6 +37,10 @@ DWORD desired_stop_thread_id = -1; std::vector pending_stops; EXCEPTION_RECORD siginfo_er; +/* Note that 'debug_events' must be locally defined in the relevant + functions. */ +#define DEBUG_EVENTS(x) if (debug_events) debug_printf x + windows_thread_info::~windows_thread_info () { CloseHandle (h); @@ -312,4 +316,46 @@ handle_exception (struct target_waitstatus *ourstatus, bool debug_exceptions) #undef DEBUG_EXCEPTION_SIMPLE } +/* See nat/windows-nat.h. */ + +bool +matching_pending_stop (bool debug_events) +{ + /* If there are pending stops, and we might plausibly hit one of + them, we don't want to actually continue the inferior -- we just + want to report the stop. In this case, we just pretend to + continue. See the comment by the definition of "pending_stops" + for details on why this is needed. */ + for (const auto &item : pending_stops) + { + if (desired_stop_thread_id == -1 + || desired_stop_thread_id == item.thread_id) + { + DEBUG_EVENTS (("windows_continue - pending stop anticipated, " + "desired=0x%x, item=0x%x\n", + desired_stop_thread_id, item.thread_id)); + return true; + } + } + + return false; +} + +/* See nat/windows-nat.h. */ + +BOOL +continue_last_debug_event (DWORD continue_status, bool debug_events) +{ + DEBUG_EVENTS (("ContinueDebugEvent (cpid=%d, ctid=0x%x, %s);\n", + (unsigned) last_wait_event.dwProcessId, + (unsigned) last_wait_event.dwThreadId, + continue_status == DBG_CONTINUE ? + "DBG_CONTINUE" : "DBG_EXCEPTION_NOT_HANDLED")); + + return ContinueDebugEvent (last_wait_event.dwProcessId, + last_wait_event.dwThreadId, + continue_status); +} + + } diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h index a4e0b39fca..0e9316577b 100644 --- a/gdb/nat/windows-nat.h +++ b/gdb/nat/windows-nat.h @@ -225,6 +225,19 @@ typedef enum extern handle_exception_result handle_exception (struct target_waitstatus *ourstatus, bool debug_exceptions); +/* Return true if there is a pending stop matching + desired_stop_thread_id. If DEBUG_EVENTS is true, logging will be + enabled. */ + +extern bool matching_pending_stop (bool debug_events); + +/* A simple wrapper for ContinueDebugEvent that continues the last + waited-for event. If DEBUG_EVENTS is true, logging will be + enabled. */ + +extern BOOL continue_last_debug_event (DWORD continue_status, + bool debug_events); + } #endif diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c index d48f90a5c7..d04dc06f3b 100644 --- a/gdb/windows-nat.c +++ b/gdb/windows-nat.c @@ -1239,28 +1239,8 @@ windows_continue (DWORD continue_status, int id, int killed) desired_stop_thread_id = id; - /* If there are pending stops, and we might plausibly hit one of - them, we don't want to actually continue the inferior -- we just - want to report the stop. In this case, we just pretend to - continue. See the comment by the definition of "pending_stops" - for details on why this is needed. */ - for (const auto &item : pending_stops) - { - if (desired_stop_thread_id == -1 - || desired_stop_thread_id == item.thread_id) - { - DEBUG_EVENTS (("windows_continue - pending stop anticipated, " - "desired=0x%x, item=0x%x\n", - desired_stop_thread_id, item.thread_id)); - return TRUE; - } - } - - DEBUG_EVENTS (("ContinueDebugEvent (cpid=%d, ctid=0x%x, %s);\n", - (unsigned) last_wait_event.dwProcessId, - (unsigned) last_wait_event.dwThreadId, - continue_status == DBG_CONTINUE ? - "DBG_CONTINUE" : "DBG_EXCEPTION_NOT_HANDLED")); + if (matching_pending_stop (debug_events)) + return TRUE; for (windows_thread_info *th : thread_list) if (id == -1 || id == (int) th->tid) @@ -1333,9 +1313,7 @@ windows_continue (DWORD continue_status, int id, int killed) th->suspend (); } - res = ContinueDebugEvent (last_wait_event.dwProcessId, - last_wait_event.dwThreadId, - continue_status); + res = continue_last_debug_event (continue_status, debug_events); if (!res) error (_("Failed to resume program execution" diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog index a00176aa42..6793795376 100644 --- a/gdbserver/ChangeLog +++ b/gdbserver/ChangeLog @@ -1,3 +1,7 @@ +2020-04-08 Tom Tromey + + * win32-low.c (child_continue): Call continue_last_debug_event. + 2020-04-08 Tom Tromey * win32-low.c (handle_exception): Remove. diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc index 7018083746..33f6470015 100644 --- a/gdbserver/win32-low.cc +++ b/gdbserver/win32-low.cc @@ -433,12 +433,7 @@ child_continue (DWORD continue_status, int thread_id) }); faked_breakpoint = 0; - if (!ContinueDebugEvent (current_event.dwProcessId, - current_event.dwThreadId, - continue_status)) - return FALSE; - - return TRUE; + return continue_last_debug_event (continue_status, debug_threads); } /* Fetch register(s) from the current thread context. */