gdbserver: turn target op 'supports_agent' into a method

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

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

	* target.h (struct process_stratum_target): Remove the target op.
	(class process_target): Add the target op.
	(target_supports_agent): Update the macro.
	* target.cc (process_target::supports_agent): Define.

	Update the derived classes and callers below.

	* linux-low.cc (linux_target_ops): Update.
	(linux_supports_agent): Turn into ...
	(linux_process_target::supports_agent): ... 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 +1,23 @@
+2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	Turn process_stratum_target's supports_agent op into a method of
+	process_target.
+
+	* target.h (struct process_stratum_target): Remove the target op.
+	(class process_target): Add the target op.
+	(target_supports_agent): Update the macro.
+	* target.cc (process_target::supports_agent): Define.
+
+	Update the derived classes and callers below.
+
+	* linux-low.cc (linux_target_ops): Update.
+	(linux_supports_agent): Turn into ...
+	(linux_process_target::supports_agent): ... 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 qxfer_libraries_svr4 op into a

gdbserver/linux-low.cc

@@ -6424,10 +6424,10 @@ linux_process_target::supports_disable_randomization ()
 #endif
 }
 
-static int
-linux_supports_agent (void)
+bool
+linux_process_target::supports_agent ()
 {
-  return 1;
+  return true;
 }
 
 static int
@@ -7463,7 +7463,6 @@ linux_get_hwcap2 (int wordsize)
 static linux_process_target the_linux_target;
 
 static process_stratum_target linux_target_ops = {
-  linux_supports_agent,
 #ifdef HAVE_LINUX_BTRACE
   linux_enable_btrace,
   linux_low_disable_btrace,

gdbserver/linux-low.h

@@ -431,6 +431,8 @@ public:
 			    unsigned char *readbuf,
 			    unsigned const char *writebuf,
 			    CORE_ADDR offset, int len) override;
+
+  bool supports_agent () 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,  /* support_agent */
   NULL,  /* enable_btrace */
   NULL,  /* disable_btrace */
   NULL,  /* read_btrace */

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, /* support_agent */
   NULL, /* enable_btrace */
   NULL, /* disable_btrace */
   NULL, /* read_btrace */

gdbserver/target.cc

@@ -720,3 +720,9 @@ process_target::qxfer_libraries_svr4 (const char *annex,
 {
   gdb_assert_not_reached ("target op qxfer_libraries_svr4 not supported");
 }
+
+bool
+process_target::supports_agent ()
+{
+  return false;
+}

gdbserver/target.h

@@ -70,9 +70,6 @@ class process_target;
    shared code.  */
 struct process_stratum_target
 {
-  /* Return true if target supports debugging agent.  */
-  int (*supports_agent) (void);
-
   /* Enable branch tracing for PTID based on CONF and allocate a branch trace
      target information struct for reading and for disabling branch trace.  */
   struct btrace_target_info *(*enable_btrace)
@@ -497,6 +494,9 @@ public:
 				    unsigned char *readbuf,
 				    unsigned const char *writebuf,
 				    CORE_ADDR offset, int len);
+
+  /* Return true if target supports debugging agent.  */
+  virtual bool supports_agent ();
 };
 
 extern process_stratum_target *the_target;
@@ -607,8 +607,7 @@ int kill_inferior (process_info *proc);
   the_target->pt->supports_disable_randomization ()
 
 #define target_supports_agent() \
-  (the_target->supports_agent ? \
-   (*the_target->supports_agent) () : 0)
+  the_target->pt->supports_agent ()
 
 static inline struct btrace_target_info *
 target_enable_btrace (ptid_t ptid, const struct btrace_config *conf)

gdbserver/win32-low.cc

@@ -1858,7 +1858,6 @@ win32_sw_breakpoint_from_kind (int kind, int *size)
 static win32_process_target the_win32_target;
 
 static process_stratum_target win32_target_ops = {
-  NULL, /* support_agent */
   NULL, /* enable_btrace */
   NULL, /* disable_btrace */
   NULL, /* read_btrace */