[PATCH 0/5] Fix to Cygwin-specific signal handling (v2)

[Jon Turney <jon.turney@dronecode.org.uk>]

Some cleanups in windows-nat.c and a fix to Cygwin-specific signal handling.

Using the 'catch-signal' test from the testsuite, on x86_64 Cygwin:

$ ./gdb testsuite/outputs/gdb.base/catch-signal/catch-signal.exe
[...]
(gdb) catch signal
Catchpoint 1 (standard signals)
(gdb) r
[...]
Catchpoint 1 (signal SIGHUP), main () at
../../../gdb/testsuite/gdb.base/catch-signal.c:40
40        raise (SIGHUP);               /* second HUP */
(gdb) c
Continuing.
[hangs]

with up to [4/5] applied:

$ ./gdb testsuite/outputs/gdb.base/catch-signal/catch-signal.exe
[...]
(gdb) catch signal
Catchpoint 1 (standard signals)
(gdb) r
[...]
Catchpoint 1 (signal SIGHUP), main () at
../../../gdb/testsuite/gdb.base/catch-signal.c:40
40        raise (SIGHUP);               /* second HUP */
(gdb) c
Continuing.
main () at ../../../gdb/testsuite/gdb.base/catch-signal.c:40
40        raise (SIGHUP);               /* second HUP */
ContinueDebugEvent failed, GetLastError = 87
(gdb)

It can be seen that changing current_event.dwThreadId as 
handle_output_debug_string does when processing a Cygwin signal message, leads 
to ContinueDebugEvent() being applied to the wrong thead, with tragic 
consequences.

with [5/5] applied:

$ ./gdb testsuite/outputs/gdb.base/catch-signal/catch-signal.exe
[...]
(gdb) catch signal
Catchpoint 1 (standard signals)
(gdb) r
[...]
Catchpoint 1 (signal SIGHUP), main () at
../../../gdb/testsuite/gdb.base/catch-signal.c:40
40        raise (SIGHUP);               /* second HUP */
(gdb) c
Continuing.
Catchpoint 1 (signal SIGHUP), main () at
../../../gdb/testsuite/gdb.base/catch-signal.c:42
42        raise (SIGHUP);               /* third HUP */
(gdb)

It looks like tests don't finish with an unresponsive gdb, and there are more 
tests in the testsuite which have this problem than my computer has cores, so 
eventually it ends up stuck on those tests, and the test run doesn't finish.

After these patches, there still remain some problems with Cygwin-specific 
signal handling, which hopefully I can address in future patches.

Jon Turney (5):
  windows-nat: Don't use ternary conditional operator in
    get_windows_debug_event
  windows-nat: Cleanups in get_windows_debug_event
  windows-nat: Fix misspelling in debug output
  windows-nat: Report an error if ContinueDebugEvent() fails
  windows-nat: Don't change current_event.dwThreadId in
    handle_output_debug_string()

 gdb/ChangeLog     | 26 ++++++++++++++++++++++++++
 gdb/windows-nat.c | 41 +++++++++++++++++++++++------------------
 2 files changed, 49 insertions(+), 18 deletions(-)

-- 
2.1.4