[PATCH v2 27/47] Windows gdb+gdbserver: Make last_sig per-thread state

[Pedro Alves <pedro@palves.net>]

With non-stop mode, each thread is controlled independently of the
others, and each thread has its own independent reason for its last
stop.

Thus, any thread-specific state that is currently per-process must be
converted to per-thread state.

This patch converts windows_process_info::last_sig to per-thread
state, moving it to windows_thread_info instead.

This adjusts both native gdb and gdbserver.

Change-Id: Ie8c673a819be445753d967afd3a6084565648448
---
 gdb/nat/windows-nat.c  |  8 +++++---
 gdb/nat/windows-nat.h  |  5 ++++-
 gdb/windows-nat.c      | 10 +++-------
 gdbserver/win32-low.cc |  7 +++----
 4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index 53d891f65d0..864788ec125 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -359,8 +359,6 @@ windows_process_info::handle_exception (DEBUG_EVENT &current_event,
 
   memcpy (&siginfo_er, rec, sizeof siginfo_er);
 
-  last_sig = GDB_SIGNAL_0;
-
   switch (code)
     {
     case EXCEPTION_ACCESS_VIOLATION:
@@ -494,7 +492,11 @@ windows_process_info::handle_exception (DEBUG_EVENT &current_event,
     }
 
   if (ourstatus->kind () == TARGET_WAITKIND_STOPPED)
-    last_sig = ourstatus->sig ();
+    {
+      ptid_t ptid (current_event.dwProcessId, current_event.dwThreadId, 0);
+      windows_thread_info *th = find_thread (ptid);
+      th->last_sig = ourstatus->sig ();
+    }
 
   return result;
 
diff --git a/gdb/nat/windows-nat.h b/gdb/nat/windows-nat.h
index 0b89c751e89..71cb118f5d6 100644
--- a/gdb/nat/windows-nat.h
+++ b/gdb/nat/windows-nat.h
@@ -104,6 +104,10 @@ struct windows_thread_info
      thread.  */
   DEBUG_EVENT last_event {};
 
+  /* The last signal reported for this thread, extracted out of
+     last_event.  */
+  enum gdb_signal last_sig = GDB_SIGNAL_0;
+
   /* The context of the thread, including any manipulations.  */
   union
   {
@@ -147,7 +151,6 @@ struct windows_process_info
   HANDLE handle = 0;
   DWORD process_id = 0;
   DWORD main_thread_id = 0;
-  enum gdb_signal last_sig = GDB_SIGNAL_0;
 
   /* Contents of $_siginfo */
   EXCEPTION_RECORD siginfo_er {};
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 8ccb7048665..87cf5e1a4e8 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -1258,6 +1258,7 @@ windows_per_inferior::continue_one_thread (windows_thread_info *th,
     });
 
   th->resume ();
+  th->last_sig = GDB_SIGNAL_0;
 }
 
 /* Resume thread specified by ID, or all artificially suspended
@@ -1358,7 +1359,7 @@ windows_nat_target::resume (ptid_t ptid, int step, enum gdb_signal sig)
 	  DEBUG_EXCEPT ("Cannot continue with signal %d here.  "
 			"Not stopped for EXCEPTION_DEBUG_EVENT", sig);
 	}
-      else if (sig == windows_process.last_sig)
+      else if (sig == th->last_sig)
 	continue_status = DBG_EXCEPTION_NOT_HANDLED;
       else
 #if 0
@@ -1382,11 +1383,9 @@ windows_nat_target::resume (ptid_t ptid, int step, enum gdb_signal sig)
 	}
 #endif
       DEBUG_EXCEPT ("Can only continue with received signal %d.",
-		    windows_process.last_sig);
+		    th->last_sig);
     }
 
-  windows_process.last_sig = GDB_SIGNAL_0;
-
   windows_process.with_context (th, [&] (auto *context)
     {
       if (step)
@@ -1486,8 +1485,6 @@ windows_nat_target::get_windows_debug_event
 	}
     }
 
-  windows_process.last_sig = GDB_SIGNAL_0;
-
   if ((options & TARGET_WNOHANG) != 0 && !m_debug_event_pending)
     {
       ourstatus->set_ignore ();
@@ -1806,7 +1803,6 @@ windows_nat_target::do_initial_windows_stuff (DWORD pid, bool attaching)
 {
   struct inferior *inf;
 
-  windows_process.last_sig = GDB_SIGNAL_0;
   windows_process.open_process_used = 0;
 #ifdef __CYGWIN__
   windows_process.cygwin_load_start = 0;
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index a4000980f67..c3e35a6f602 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -289,7 +289,6 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
 {
   struct process_info *proc;
 
-  windows_process.last_sig = GDB_SIGNAL_0;
   windows_process.handle = proch;
   windows_process.process_id = pid;
   windows_process.main_thread_id = 0;
@@ -396,6 +395,7 @@ continue_one_thread (thread_info *thread, int thread_id)
 	    }
 
 	  th->resume ();
+	  th->last_sig = GDB_SIGNAL_0;
 	}
     }
 }
@@ -758,11 +758,11 @@ resume_one_thread (thread_info *thread, bool step, gdb_signal sig,
 		   "Not stopped for EXCEPTION_DEBUG_EVENT.\n",
 		   gdb_signal_to_string (sig)));
 	}
-      else if (sig == windows_process.last_sig)
+      else if (sig == th->last_sig)
 	*continue_status = DBG_EXCEPTION_NOT_HANDLED;
       else
 	OUTMSG (("Can only continue with received signal %s.\n",
-		 gdb_signal_to_string (windows_process.last_sig)));
+		 gdb_signal_to_string (th->last_sig)));
     }
 
   win32_prepare_to_resume (th);
@@ -957,7 +957,6 @@ get_child_debug_event (DWORD *continue_status,
 {
   ptid_t ptid;
 
-  windows_process.last_sig = GDB_SIGNAL_0;
   ourstatus->set_spurious ();
   *continue_status = DBG_CONTINUE;
 
-- 
2.49.0