gdbserver: turn target op 'thread_stopped' into a method

gdbserver/ChangeLog:
2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	Turn process_stratum_target's thread_stopped op into a method of
	process_target.

	* target.h (struct process_stratum_target): Remove the target op.
	(class process_target): Add the target op.  Also add
	'supports_thread_stopped'.
	(target_thread_stopped): Update the macro.
	* target.cc (process_target::thread_stopped): Define.
	(process_target::supports_thread_stopped): Define.
	(prepare_to_access_memory): Update.

	Update the derived classes and callers below.

	* server.cc (queue_stop_reply_callback): Update.
	* linux-low.cc (linux_target_ops): Update.
	(linux_process_target::supports_thread_stopped): Define.
	(linux_thread_stopped): Turn into ...
	(linux_process_target::thread_stopped): ... this.
	* linux-low.h (class linux_process_target): Update.
	* lynx-low.cc (lynx_target_ops): Update.
	* nto-low.cc (nto_target_ops): Update.
	* win32-low.cc (win32_target_ops): Update.

gdbserver/ChangeLog

@@ -1,3 +1,28 @@
+2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	Turn process_stratum_target's thread_stopped op into a method of
+	process_target.
+
+	* target.h (struct process_stratum_target): Remove the target op.
+	(class process_target): Add the target op.  Also add
+	'supports_thread_stopped'.
+	(target_thread_stopped): Update the macro.
+	* target.cc (process_target::thread_stopped): Define.
+	(process_target::supports_thread_stopped): Define.
+	(prepare_to_access_memory): Update.
+
+	Update the derived classes and callers below.
+
+	* server.cc (queue_stop_reply_callback): Update.
+	* linux-low.cc (linux_target_ops): Update.
+	(linux_process_target::supports_thread_stopped): Define.
+	(linux_thread_stopped): Turn into ...
+	(linux_process_target::thread_stopped): ... this.
+	* linux-low.h (class linux_process_target): Update.
+	* lynx-low.cc (lynx_target_ops): Update.
+	* nto-low.cc (nto_target_ops): Update.
+	* win32-low.cc (win32_target_ops): Update.
+
 2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
 
 	Turn process_stratum_target's read_pc and write_pc ops into

gdbserver/linux-low.cc

@@ -6572,8 +6572,14 @@ linux_process_target::write_pc (regcache *regcache, CORE_ADDR pc)
   (*the_low_target.set_pc) (regcache, pc);
 }
 
-static int
+bool
-linux_thread_stopped (struct thread_info *thread)
+linux_process_target::supports_thread_stopped ()
+{
+  return true;
+}
+
+bool
+linux_process_target::thread_stopped (thread_info *thread)
 {
   return get_thread_lwp (thread)->stopped;
 }
@@ -7449,7 +7455,6 @@ linux_get_hwcap2 (int wordsize)
 static linux_process_target the_linux_target;
 
 static process_stratum_target linux_target_ops = {
-  linux_thread_stopped,
   NULL,
   linux_pause_all,
   linux_unpause_all,

gdbserver/linux-low.h

@@ -392,6 +392,10 @@ public:
   CORE_ADDR read_pc (regcache *regcache) override;
 
   void write_pc (regcache *regcache, CORE_ADDR pc) override;
+
+  bool supports_thread_stopped () override;
+
+  bool thread_stopped (thread_info *thread) override;
 };
 
 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))

gdbserver/lynx-low.cc

@@ -735,7 +735,6 @@ static lynx_process_target the_lynx_target;
 /* The LynxOS target_ops vector.  */
 
 static process_stratum_target lynx_target_ops = {
-  NULL,  /* thread_stopped */
   NULL,  /* get_tib_address */
   NULL,  /* pause_all */
   NULL,  /* unpause_all */

gdbserver/nto-low.cc

@@ -947,7 +947,6 @@ nto_sw_breakpoint_from_kind (int kind, int *size)
 static nto_process_target the_nto_target;
 
 static process_stratum_target nto_target_ops = {
-  NULL, /* thread_stopped */
   NULL, /* get_tib_address */
   NULL, /* pause_all */
   NULL, /* unpause_all */

gdbserver/server.cc

@@ -3217,7 +3217,7 @@ queue_stop_reply_callback (thread_info *thread)
 {
   /* For now, assume targets that don't have this callback also don't
      manage the thread's last_status field.  */
-  if (the_target->thread_stopped == NULL)
+  if (!the_target->pt->supports_thread_stopped ())
     {
       struct vstop_notif *new_notif = new struct vstop_notif;
 
@@ -3229,7 +3229,7 @@ queue_stop_reply_callback (thread_info *thread)
     }
   else
     {
-      if (thread_stopped (thread))
+      if (target_thread_stopped (thread))
 	{
 	  if (debug_threads)
 	    {

gdbserver/target.cc

@@ -66,8 +66,8 @@ prepare_to_access_memory (void)
     {
       if (mythread_alive (thread->id))
 	{
-	  if (stopped == NULL && the_target->thread_stopped != NULL
+	  if (stopped == NULL && the_target->pt->supports_thread_stopped ()
-	      && thread_stopped (thread))
+	      && target_thread_stopped (thread))
 	    stopped = thread;
 
 	  if (first == NULL)
@@ -626,3 +626,15 @@ process_target::write_pc (regcache *regcache, CORE_ADDR pc)
 {
   gdb_assert_not_reached ("process_target::write_pc: Unable to update PC");
 }
+
+bool
+process_target::supports_thread_stopped ()
+{
+  return false;
+}
+
+bool
+process_target::thread_stopped (thread_info *thread)
+{
+  gdb_assert_not_reached ("target op thread_stopped not supported");
+}

gdbserver/target.h

@@ -70,9 +70,6 @@ class process_target;
    shared code.  */
 struct process_stratum_target
 {
-  /* Return true if THREAD is known to be stopped now.  */
-  int (*thread_stopped) (struct thread_info *thread);
-
   /* Read Thread Information Block address.  */
   int (*get_tib_address) (ptid_t ptid, CORE_ADDR *address);
 
@@ -488,6 +485,12 @@ public:
 
   /* Write PC to REGCACHE.  */
   virtual void write_pc (regcache *regcache, CORE_ADDR pc);
+
+  /* Return true if the thread_stopped op is supported.  */
+  virtual bool supports_thread_stopped ();
+
+  /* Return true if THREAD is known to be stopped now.  */
+  virtual bool thread_stopped (thread_info *thread);
 };
 
 extern process_stratum_target *the_target;
@@ -559,8 +562,8 @@ int kill_inferior (process_info *proc);
   (the_target->get_min_fast_tracepoint_insn_len		\
    ? (*the_target->get_min_fast_tracepoint_insn_len) () : 0)
 
-#define thread_stopped(thread) \
+#define target_thread_stopped(thread) \
-  (*the_target->thread_stopped) (thread)
+  the_target->pt->thread_stopped (thread)
 
 #define pause_all(freeze)			\
   do						\

gdbserver/win32-low.cc

@@ -1852,7 +1852,6 @@ win32_sw_breakpoint_from_kind (int kind, int *size)
 static win32_process_target the_win32_target;
 
 static process_stratum_target win32_target_ops = {
-  NULL, /* thread_stopped */
   win32_get_tib_address,
   NULL, /* pause_all */
   NULL, /* unpause_all */