Use subclasses of windows_process_info

This changes windows_process_info to use virtual methods for its
callbacks, and then changes the two clients of this code to subclass
this class to implement the methods.

I considered using CRTP here, but that would require making the new
structures visible to the compilation of of nat/windows-nat.c.  This
seemed like a bit of a pain, so I didn't do it.

This change then lets us change all the per-inferior globals to be
members of the new subclass.  Note that there can still only be a
single inferior -- currently there's a single global of the new type.
This is just another step toward possibly implementing multi-inferior
for Windows.

It's possible this could be cleaned up further... ideally I'd like to
move more of the data into the base class.  However, because gdb
supports Cygwin and gdbserver does not, and because I don't have a way
to build or test Cygwin, larger refactorings are difficult.

2 files changed, 65 insertions, 56 deletions

diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index a9af646..2722407 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -39,7 +39,7 @@
 using namespace windows_nat;
 
 /* See win32-low.h.  */
-windows_process_info windows_process;
+gdbserver_windows_process windows_process;
 
 #ifndef USE_WIN32API
 #include <sys/cygwin.h>
@@ -67,25 +67,6 @@ windows_process_info windows_process;
 
 int using_threads = 1;
 
-/* Globals.  */
-static int attaching = 0;
-
-/* A status that hasn't been reported to the core yet, and so
-   win32_wait should return it next, instead of fetching the next
-   debug event off the win32 API.  */
-static struct target_waitstatus cached_status;
-
-/* Non zero if an interrupt request is to be satisfied by suspending
-   all threads.  */
-static int soft_interrupt_requested = 0;
-
-/* Non zero if the inferior is stopped in a simulated breakpoint done
-   by suspending all the threads.  */
-static int faked_breakpoint = 0;
-
-/* True if current_process_handle needs to be closed.  */
-static bool open_process_used = false;
-
 const struct target_desc *win32_tdesc;
 #ifdef __x86_64__
 const struct target_desc *wow64_win32_tdesc;
@@ -166,7 +147,7 @@ win32_require_context (windows_thread_info *th)
 /* See nat/windows-nat.h.  */
 
 windows_thread_info *
-windows_nat::windows_process_info::thread_rec
+gdbserver_windows_process::thread_rec
      (ptid_t ptid, thread_disposition_type disposition)
 {
   thread_info *thread = find_thread_ptid (ptid);
@@ -326,10 +307,6 @@ child_init_thread_list (void)
   for_each_thread (delete_thread_info);
 }
 
-/* Zero during the child initialization phase, and nonzero otherwise.  */
-
-static int child_initialization_done = 0;
-
 static void
 do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
 {
@@ -339,9 +316,9 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
   windows_process.handle = proch;
   windows_process.main_thread_id = 0;
 
-  soft_interrupt_requested = 0;
-  faked_breakpoint = 0;
-  open_process_used = true;
+  windows_process.soft_interrupt_requested = 0;
+  windows_process.faked_breakpoint = 0;
+  windows_process.open_process_used = true;
 
   memset (&windows_process.current_event, 0,
 	  sizeof (windows_process.current_event));
@@ -373,12 +350,12 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
 #endif
     proc->tdesc = win32_tdesc;
   child_init_thread_list ();
-  child_initialization_done = 0;
+  windows_process.child_initialization_done = 0;
 
   if (the_low_target.initial_stuff != NULL)
     (*the_low_target.initial_stuff) ();
 
-  cached_status.set_ignore ();
+  windows_process.cached_status.set_ignore ();
 
   /* Flush all currently pending debug events (thread and dll list) up
      to the initial breakpoint.  */
@@ -391,7 +368,7 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
       /* Note win32_wait doesn't return thread events.  */
       if (status.kind () != TARGET_WAITKIND_LOADED)
 	{
-	  cached_status = status;
+	  windows_process.cached_status = status;
 	  break;
 	}
 
@@ -423,7 +400,7 @@ do_initial_child_stuff (HANDLE proch, DWORD pid, int attached)
      phase, and then process them all in one batch now.  */
   windows_process.add_all_dlls ();
 
-  child_initialization_done = 1;
+  windows_process.child_initialization_done = 1;
 }
 
 /* Resume all artificially suspended threads if we are continuing
@@ -470,7 +447,7 @@ child_continue (DWORD continue_status, int thread_id)
     {
       continue_one_thread (thread, thread_id);
     });
-  faked_breakpoint = 0;
+  windows_process.faked_breakpoint = 0;
 
   return continue_last_debug_event (continue_status, debug_threads);
 }
@@ -615,7 +592,7 @@ win32_process_target::create_inferior (const char *program,
   char *args = (char *) str_program_args.c_str ();
 
   /* win32_wait needs to know we're not attaching.  */
-  attaching = 0;
+  windows_process.attaching = 0;
 
   if (!program)
     error ("No executable specified, specify executable to debug.\n");
@@ -700,7 +677,7 @@ win32_process_target::attach (unsigned long pid)
 	  DebugSetProcessKillOnExit (FALSE);
 
 	  /* win32_wait needs to know we're attaching.  */
-	  attaching = 1;
+	  windows_process.attaching = 1;
 	  do_initial_child_stuff (h, pid, 1);
 	  return 0;
 	}
@@ -716,7 +693,7 @@ win32_process_target::attach (unsigned long pid)
 /* See nat/windows-nat.h.  */
 
 int
-windows_nat::windows_process_info::handle_output_debug_string
+gdbserver_windows_process::handle_output_debug_string
      (struct target_waitstatus *ourstatus)
 {
 #define READ_BUFFER_LEN 1024
@@ -765,10 +742,10 @@ windows_nat::windows_process_info::handle_output_debug_string
 static void
 win32_clear_inferiors (void)
 {
-  if (open_process_used)
+  if (windows_process.open_process_used)
     {
       CloseHandle (windows_process.handle);
-      open_process_used = false;
+      windows_process.open_process_used = false;
     }
 
   for_each_thread (delete_thread_info);
@@ -946,8 +923,7 @@ win32_process_target::resume (thread_resume *resume_info, size_t n)
 /* See nat/windows-nat.h.  */
 
 void
-windows_nat::windows_process_info::handle_load_dll (const char *name,
-						    LPVOID base)
+gdbserver_windows_process::handle_load_dll (const char *name, LPVOID base)
 {
   CORE_ADDR load_addr = (CORE_ADDR) (uintptr_t) base;
 
@@ -1001,7 +977,7 @@ windows_nat::windows_process_info::handle_load_dll (const char *name,
 /* See nat/windows-nat.h.  */
 
 void
-windows_nat::windows_process_info::handle_unload_dll ()
+gdbserver_windows_process::handle_unload_dll ()
 {
   CORE_ADDR load_addr =
 	  (CORE_ADDR) (uintptr_t) current_event.u.UnloadDll.lpBaseOfDll;
@@ -1026,7 +1002,7 @@ fake_breakpoint_event (void)
 {
   OUTMSG2(("fake_breakpoint_event\n"));
 
-  faked_breakpoint = 1;
+  windows_process.faked_breakpoint = 1;
 
   memset (&windows_process.current_event, 0,
 	  sizeof (windows_process.current_event));
@@ -1041,7 +1017,7 @@ fake_breakpoint_event (void)
 /* See nat/windows-nat.h.  */
 
 bool
-windows_nat::windows_process_info::handle_access_violation
+gdbserver_windows_process::handle_access_violation
      (const EXCEPTION_RECORD *rec)
 {
   return false;
@@ -1067,7 +1043,7 @@ maybe_adjust_pc ()
 	   == EXCEPTION_BREAKPOINT)
 	  || (windows_process.current_event.u.Exception.ExceptionRecord.ExceptionCode
 	      == STATUS_WX86_BREAKPOINT))
-      && child_initialization_done)
+      && windows_process.child_initialization_done)
     {
       th->stopped_at_software_breakpoint = true;
       CORE_ADDR pc = regcache_read_pc (regcache);
@@ -1093,14 +1069,14 @@ get_child_debug_event (DWORD *continue_status,
 
   DEBUG_EVENT *current_event = &windows_process.current_event;
 
-  if (soft_interrupt_requested)
+  if (windows_process.soft_interrupt_requested)
     {
-      soft_interrupt_requested = 0;
+      windows_process.soft_interrupt_requested = 0;
       fake_breakpoint_event ();
       goto gotevent;
     }
 
-  attaching = 0;
+  windows_process.attaching = 0;
   {
     gdb::optional<pending_stop> stop
       = windows_process.fetch_pending_stop (debug_threads);
@@ -1169,10 +1145,10 @@ get_child_debug_event (DWORD *continue_status,
 		(unsigned) current_event->dwThreadId));
       CloseHandle (current_event->u.CreateProcessInfo.hFile);
 
-      if (open_process_used)
+      if (windows_process.open_process_used)
 	{
 	  CloseHandle (windows_process.handle);
-	  open_process_used = false;
+	  windows_process.open_process_used = false;
 	}
 
       windows_process.handle = current_event->u.CreateProcessInfo.hProcess;
@@ -1211,7 +1187,7 @@ get_child_debug_event (DWORD *continue_status,
 		(unsigned) current_event->dwProcessId,
 		(unsigned) current_event->dwThreadId));
       CloseHandle (current_event->u.LoadDll.hFile);
-      if (! child_initialization_done)
+      if (! windows_process.child_initialization_done)
 	break;
       windows_process.dll_loaded_event ();
 
@@ -1223,7 +1199,7 @@ get_child_debug_event (DWORD *continue_status,
 		"for pid=%u tid=%x\n",
 		(unsigned) current_event->dwProcessId,
 		(unsigned) current_event->dwThreadId));
-      if (! child_initialization_done)
+      if (! windows_process.child_initialization_done)
 	break;
       windows_process.handle_unload_dll ();
       ourstatus->set_loaded ();
@@ -1285,14 +1261,14 @@ ptid_t
 win32_process_target::wait (ptid_t ptid, target_waitstatus *ourstatus,
 			    target_wait_flags options)
 {
-  if (cached_status.kind () != TARGET_WAITKIND_IGNORE)
+  if (windows_process.cached_status.kind () != TARGET_WAITKIND_IGNORE)
     {
       /* The core always does a wait after creating the inferior, and
 	 do_initial_child_stuff already ran the inferior to the
 	 initial breakpoint (or an exit, if creating the process
 	 fails).  Report it now.  */
-      *ourstatus = cached_status;
-      cached_status.set_ignore ();
+      *ourstatus = windows_process.cached_status;
+      windows_process.cached_status.set_ignore ();
       return debug_event_ptid (&windows_process.current_event);
     }
 
@@ -1384,7 +1360,7 @@ win32_process_target::request_interrupt ()
     return;
 
   /* Last resort, suspend all threads manually.  */
-  soft_interrupt_requested = 1;
+  windows_process.soft_interrupt_requested = 1;
 }
 
 bool
diff --git a/gdbserver/win32-low.h b/gdbserver/win32-low.h
index b29e8b3..58bb105 100644
--- a/gdbserver/win32-low.h
+++ b/gdbserver/win32-low.h
@@ -172,8 +172,41 @@ public:
   }
 };
 
+struct gdbserver_windows_process : public windows_nat::windows_process_info
+{
+  windows_nat::windows_thread_info *thread_rec
+       (ptid_t ptid,
+	windows_nat::thread_disposition_type disposition) override;
+  int handle_output_debug_string (struct target_waitstatus *ourstatus) override;
+  void handle_load_dll (const char *dll_name, LPVOID base) override;
+  void handle_unload_dll () override;
+  bool handle_access_violation (const EXCEPTION_RECORD *rec) override;
+
+  int attaching = 0;
+
+  /* A status that hasn't been reported to the core yet, and so
+     win32_wait should return it next, instead of fetching the next
+     debug event off the win32 API.  */
+  struct target_waitstatus cached_status;
+
+  /* Non zero if an interrupt request is to be satisfied by suspending
+     all threads.  */
+  int soft_interrupt_requested = 0;
+
+  /* Non zero if the inferior is stopped in a simulated breakpoint done
+     by suspending all the threads.  */
+  int faked_breakpoint = 0;
+
+  /* True if current_process_handle needs to be closed.  */
+  bool open_process_used = false;
+
+  /* Zero during the child initialization phase, and nonzero
+     otherwise.  */
+  int child_initialization_done = 0;
+};
+
 /* The sole Windows process.  */
-extern windows_nat::windows_process_info windows_process;
+extern gdbserver_windows_process windows_process;
 
 /* Retrieve the context for this thread, if not already retrieved.  */
 extern void win32_require_context (windows_nat::windows_thread_info *th);