[C++/mingw] Simplify first chance exception handling

Building in C++ errors out with:

../../src/gdb/windows-nat.c: In function 'int get_windows_debug_event(target_ops*, int, target_waitstatus*)':
../../src/gdb/windows-nat.c:1503:13: warning: invalid conversion from 'int' to 'gdb_signal' [-fpermissive]
    last_sig = 1;
             ^
../../src/gdb/windows-nat.c:1533:43: warning: invalid conversion from 'int' to 'gdb_signal' [-fpermissive]
  windows_resume (ops, minus_one_ptid, 0, 1);
                                           ^
../../src/gdb/windows-nat.c:1228:1: warning:   initializing argument 4 of 'void windows_resume(target_ops*, ptid_t, int, gdb_signal)' [-fpermissive]
 windows_resume (struct target_ops *ops,
 ^

Looking at the code, I can't figure out why we treat first chance
exceptions any different here.

AFAICS, we set last_sig to 1, and then call windows_resume passing
signal==1, so the DBG_EXCEPTION_NOT_HANDLED code path in win32_resume
is taken:

~~~
  if (sig != GDB_SIGNAL_0)
    {
      if (current_event.dwDebugEventCode != EXCEPTION_DEBUG_EVENT)
	{
	  OUTMSG (("Cannot continue with signal %d here.\n", sig));
	}
      else if (sig == last_sig)
	continue_status = DBG_EXCEPTION_NOT_HANDLED;
      else
	OUTMSG (("Can only continue with recieved signal %d.\n", last_sig));
    }
~~~

Fix this by removing this special casing.  gdbserver also goes
straight to continuing with DBG_EXCEPTION_NOT_HANDLED, AFAICS.

gdb/ChangeLog:
2015-11-17  Pedro Alves  <palves@redhat.com>

	* windows-nat.c (handle_exception): Return 0 for first chance
	exceptions.
	(get_windows_debug_event): Adjust.
This commit is contained in:
Pedro Alves 2015-11-17 15:17:45 +00:00
parent ce7715e259
commit 95824559df
2 changed files with 12 additions and 18 deletions

View File

@ -1,3 +1,9 @@
2015-11-17 Pedro Alves <palves@redhat.com>
* windows-nat.c (handle_exception): Return 0 for first chance
exceptions.
(get_windows_debug_event): Adjust.
2015-11-17 Pedro Alves <palves@redhat.com>
* windows-nat.c (xslate): Use GDB_SIGNAL_UNKNOWN instead of -1 as

View File

@ -1124,7 +1124,7 @@ handle_exception (struct target_waitstatus *ourstatus)
default:
/* Treat unhandled first chance exceptions specially. */
if (current_event.u.Exception.dwFirstChance)
return -1;
return 0;
printf_unfiltered ("gdb: unknown target exception 0x%08x at %s\n",
(unsigned) current_event.u.Exception.ExceptionRecord.ExceptionCode,
host_address_to_string (
@ -1491,19 +1491,10 @@ get_windows_debug_event (struct target_ops *ops,
"EXCEPTION_DEBUG_EVENT"));
if (saw_create != 1)
break;
switch (handle_exception (ourstatus))
{
case 0:
continue_status = DBG_EXCEPTION_NOT_HANDLED;
break;
case 1:
thread_id = current_event.dwThreadId;
break;
case -1:
last_sig = 1;
continue_status = -1;
break;
}
if (handle_exception (ourstatus))
thread_id = current_event.dwThreadId;
else
continue_status = DBG_EXCEPTION_NOT_HANDLED;
break;
case OUTPUT_DEBUG_STRING_EVENT: /* Message from the kernel. */
@ -1529,10 +1520,7 @@ get_windows_debug_event (struct target_ops *ops,
if (!thread_id || saw_create != 1)
{
if (continue_status == -1)
windows_resume (ops, minus_one_ptid, 0, 1);
else
CHECK (windows_continue (continue_status, -1, 0));
CHECK (windows_continue (continue_status, -1, 0));
}
else
{