Share some Windows-related globals

This moves some Windows-related globals into nat/windows-nat.c,
sharing them between gdb and gdbserver.

gdb/ChangeLog
2020-04-08  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (current_process_handle, current_process_id)
	(main_thread_id, last_sig, current_event, last_wait_event)
	(current_windows_thread, desired_stop_thread_id, pending_stops)
	(struct pending_stop, siginfo_er): Move to nat/windows-nat.c.
	(display_selectors, fake_create_process)
	(get_windows_debug_event): Update.
	* nat/windows-nat.h (current_process_handle, current_process_id)
	(main_thread_id, last_sig, current_event, last_wait_event)
	(current_windows_thread, desired_stop_thread_id, pending_stops)
	(struct pending_stop, siginfo_er): Move from windows-nat.c.
	* nat/windows-nat.c (current_process_handle, current_process_id)
	(main_thread_id, last_sig, current_event, last_wait_event)
	(current_windows_thread, desired_stop_thread_id, pending_stops)
	(siginfo_er): New globals.  Move from windows-nat.c.

gdbserver/ChangeLog
2020-04-08  Tom Tromey  <tromey@adacore.com>

	* win32-low.c (current_process_handle, current_process_id)
	(main_thread_id, last_sig, current_event, siginfo_er): Move to
	nat/windows-nat.c.

2 files changed, 69 insertions, 1 deletions

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index 8217a98..80a1583 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -1,5 +1,5 @@
 /* Internal interfaces for the Windows code
-   Copyright (C) 1995-2019 Free Software Foundation, Inc.
+   Copyright (C) 1995-2020 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -22,6 +22,17 @@
 namespace windows_nat
 {
 
+HANDLE current_process_handle;
+DWORD current_process_id;
+DWORD main_thread_id;
+enum gdb_signal last_sig = GDB_SIGNAL_0;
+DEBUG_EVENT current_event;
+DEBUG_EVENT last_wait_event;
+windows_thread_info *current_windows_thread;
+DWORD desired_stop_thread_id = -1;
+std::vector<pending_stop> pending_stops;
+EXCEPTION_RECORD siginfo_er;
+
 windows_thread_info::~windows_thread_info ()
 {
   CloseHandle (h);
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 4176ed7..501147b 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -20,6 +20,9 @@
 #define NAT_WINDOWS_NAT_H
 
 #include <windows.h>
+#include <vector>
+
+#include "target/waitstatus.h"
 
 namespace windows_nat
 {
@@ -111,6 +114,60 @@ enum thread_disposition_type
 extern windows_thread_info *thread_rec (ptid_t ptid,
 					thread_disposition_type disposition);
 
+/* Currently executing process */
+extern HANDLE current_process_handle;
+extern DWORD current_process_id;
+extern DWORD main_thread_id;
+extern enum gdb_signal last_sig;
+
+/* The current debug event from WaitForDebugEvent or from a pending
+   stop.  */
+extern DEBUG_EVENT current_event;
+
+/* The most recent event from WaitForDebugEvent.  Unlike
+   current_event, this is guaranteed never to come from a pending
+   stop.  This is important because only data from the most recent
+   event from WaitForDebugEvent can be used when calling
+   ContinueDebugEvent.  */
+extern DEBUG_EVENT last_wait_event;
+
+/* Info on currently selected thread */
+extern windows_thread_info *current_windows_thread;
+
+/* The ID of the thread for which we anticipate a stop event.
+   Normally this is -1, meaning we'll accept an event in any
+   thread.  */
+extern DWORD desired_stop_thread_id;
+
+/* A single pending stop.  See "pending_stops" for more
+   information.  */
+struct pending_stop
+{
+  /* The thread id.  */
+  DWORD thread_id;
+
+  /* The target waitstatus we computed.  */
+  target_waitstatus status;
+
+  /* The event.  A few fields of this can be referenced after a stop,
+     and it seemed simplest to store the entire event.  */
+  DEBUG_EVENT event;
+};
+
+/* A vector of pending stops.  Sometimes, Windows will report a stop
+   on a thread that has been ostensibly suspended.  We believe what
+   happens here is that two threads hit a breakpoint simultaneously,
+   and the Windows kernel queues the stop events.  However, this can
+   result in the strange effect of trying to single step thread A --
+   leaving all other threads suspended -- and then seeing a stop in
+   thread B.  To handle this scenario, we queue all such "pending"
+   stops here, and then process them once the step has completed.  See
+   PR gdb/22992.  */
+extern std::vector<pending_stop> pending_stops;
+
+/* Contents of $_siginfo */
+extern EXCEPTION_RECORD siginfo_er;
+
 /* Return the name of the DLL referenced by H at ADDRESS.  UNICODE
    determines what sort of string is read from the inferior.  Returns
    the name of the DLL, or NULL on error.  If a name is returned, it