[v2,48/58] gdbserver: turn btrace-related target ops into methods

diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc
index 9ba2927eef4..1af37044a8e 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -7149,10 +7149,17 @@  linux_process_target::qxfer_libraries_svr4 (const char *annex,
 
 #ifdef HAVE_LINUX_BTRACE
 
+btrace_target_info *
+linux_process_target::enable_btrace (ptid_t ptid,
+				     const btrace_config *conf)
+{
+  return linux_enable_btrace (ptid, conf);
+}
+
 /* See to_disable_btrace target method.  */
 
-static int
-linux_low_disable_btrace (struct btrace_target_info *tinfo)
+int
+linux_process_target::disable_btrace (btrace_target_info *tinfo)
 {
   enum btrace_error err;
 
@@ -7211,9 +7218,10 @@  linux_low_encode_raw (struct buffer *buffer, const gdb_byte *data,
 
 /* See to_read_btrace target method.  */
 
-static int
-linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
-		       enum btrace_read_type type)
+int
+linux_process_target::read_btrace (btrace_target_info *tinfo,
+				   buffer *buffer,
+				   enum btrace_read_type type)
 {
   struct btrace_data btrace;
   enum btrace_error err;
@@ -7270,9 +7278,9 @@  linux_low_read_btrace (struct btrace_target_info *tinfo, struct buffer *buffer,
 
 /* See to_btrace_conf target method.  */
 
-static int
-linux_low_btrace_conf (const struct btrace_target_info *tinfo,
-		       struct buffer *buffer)
+int
+linux_process_target::read_btrace_conf (const btrace_target_info *tinfo,
+					buffer *buffer)
 {
   const struct btrace_config *conf;
 
@@ -7459,17 +7467,6 @@  linux_get_hwcap2 (int wordsize)
 static linux_process_target the_linux_target;
 
 static process_stratum_target linux_target_ops = {
-#ifdef HAVE_LINUX_BTRACE
-  linux_enable_btrace,
-  linux_low_disable_btrace,
-  linux_low_read_btrace,
-  linux_low_btrace_conf,
-#else
-  NULL,
-  NULL,
-  NULL,
-  NULL,
-#endif
   linux_supports_range_stepping,
   linux_proc_pid_to_exec_file,
   linux_mntns_open_cloexec,
diff --git a/gdbserver/linux-low.h b/gdbserver/linux-low.h
index 0f0f3e0b869..8c33dccc678 100644
--- a/gdbserver/linux-low.h
+++ b/gdbserver/linux-low.h
@@ -433,6 +433,19 @@  public:
 			    CORE_ADDR offset, int len) override;
 
   bool supports_agent () override;
+
+#ifdef HAVE_LINUX_BTRACE
+  btrace_target_info *enable_btrace (ptid_t ptid,
+				     const btrace_config *conf) override;
+
+  int disable_btrace (btrace_target_info *tinfo) override;
+
+  int read_btrace (btrace_target_info *tinfo, buffer *buf,
+		   enum btrace_read_type type) override;
+
+  int read_btrace_conf (const btrace_target_info *tinfo,
+			buffer *buf) override;
+#endif
 };
 
 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
diff --git a/gdbserver/lynx-low.cc b/gdbserver/lynx-low.cc
index 031166ed126..a890b660bb1 100644
--- a/gdbserver/lynx-low.cc
+++ b/gdbserver/lynx-low.cc
@@ -735,10 +735,6 @@  static lynx_process_target the_lynx_target;
 /* The LynxOS target_ops vector.  */
 
 static process_stratum_target lynx_target_ops = {
-  NULL,  /* enable_btrace */
-  NULL,  /* disable_btrace */
-  NULL,  /* read_btrace */
-  NULL,  /* read_btrace_conf */
   NULL,  /* supports_range_stepping */
   NULL,  /* pid_to_exec_file */
   NULL,  /* multifs_open */
diff --git a/gdbserver/nto-low.cc b/gdbserver/nto-low.cc
index 27fe3ca4132..ef79105877b 100644
--- a/gdbserver/nto-low.cc
+++ b/gdbserver/nto-low.cc
@@ -947,10 +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, /* enable_btrace */
-  NULL, /* disable_btrace */
-  NULL, /* read_btrace */
-  NULL, /* read_btrace_conf */
   NULL, /* supports_range_stepping */
   NULL, /* pid_to_exec_file */
   NULL, /* multifs_open */
diff --git a/gdbserver/target.cc b/gdbserver/target.cc
index 2bbd8b4d7a9..e2ce7ff0869 100644
--- a/gdbserver/target.cc
+++ b/gdbserver/target.cc
@@ -726,3 +726,30 @@  process_target::supports_agent ()
 {
   return false;
 }
+
+btrace_target_info *
+process_target::enable_btrace (ptid_t ptid, const btrace_config *conf)
+{
+  error (_("Target does not support branch tracing."));
+}
+
+int
+process_target::disable_btrace (btrace_target_info *tinfo)
+{
+  error (_("Target does not support branch tracing."));
+}
+
+int
+process_target::read_btrace (btrace_target_info *tinfo,
+			     buffer *buffer,
+			     enum btrace_read_type type)
+{
+  error (_("Target does not support branch tracing."));
+}
+
+int
+process_target::read_btrace_conf (const btrace_target_info *tinfo,
+				  buffer *buffer)
+{
+  error (_("Target does not support branch tracing."));
+}
diff --git a/gdbserver/target.h b/gdbserver/target.h
index 8a1c12260f1..9d7c599b1e6 100644
--- a/gdbserver/target.h
+++ b/gdbserver/target.h
@@ -70,26 +70,6 @@  class process_target;
    shared code.  */
 struct process_stratum_target
 {
-  /* 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)
-    (ptid_t ptid, const struct btrace_config *conf);
-
-  /* Disable branch tracing.
-     Returns zero on success, non-zero otherwise.  */
-  int (*disable_btrace) (struct btrace_target_info *tinfo);
-
-  /* Read branch trace data into buffer.
-     Return 0 on success; print an error message into BUFFER and return -1,
-     otherwise.  */
-  int (*read_btrace) (struct btrace_target_info *, struct buffer *,
-		      enum btrace_read_type type);
-
-  /* Read the branch trace configuration into BUFFER.
-     Return 0 on success; print an error message into BUFFER and return -1
-     otherwise.  */
-  int (*read_btrace_conf) (const struct btrace_target_info *, struct buffer *);
-
   /* Return true if target supports range stepping.  */
   int (*supports_range_stepping) (void);
 
@@ -497,6 +477,27 @@  public:
 
   /* Return true if target supports debugging agent.  */
   virtual bool supports_agent ();
+
+  /* Enable branch tracing for PTID based on CONF and allocate a branch trace
+     target information struct for reading and for disabling branch trace.  */
+  virtual btrace_target_info *enable_btrace (ptid_t ptid,
+					     const btrace_config *conf);
+
+  /* Disable branch tracing.
+     Returns zero on success, non-zero otherwise.  */
+  virtual int disable_btrace (btrace_target_info *tinfo);
+
+  /* Read branch trace data into buffer.
+     Return 0 on success; print an error message into BUFFER and return -1,
+     otherwise.  */
+  virtual int read_btrace (btrace_target_info *tinfo, buffer *buf,
+			   enum btrace_read_type type);
+
+  /* Read the branch trace configuration into BUFFER.
+     Return 0 on success; print an error message into BUFFER and return -1
+     otherwise.  */
+  virtual int read_btrace_conf (const btrace_target_info *tinfo,
+				buffer *buf);
 };
 
 extern process_stratum_target *the_target;
@@ -612,19 +613,13 @@  int kill_inferior (process_info *proc);
 static inline struct btrace_target_info *
 target_enable_btrace (ptid_t ptid, const struct btrace_config *conf)
 {
-  if (the_target->enable_btrace == nullptr)
-    error (_("Target does not support branch tracing."));
-
-  return (*the_target->enable_btrace) (ptid, conf);
+  return the_target->pt->enable_btrace (ptid, conf);
 }
 
 static inline int
 target_disable_btrace (struct btrace_target_info *tinfo)
 {
-  if (the_target->disable_btrace == nullptr)
-    error (_("Target does not support branch tracing."));
-
-  return (*the_target->disable_btrace) (tinfo);
+  return the_target->pt->disable_btrace (tinfo);
 }
 
 static inline int
@@ -632,20 +627,14 @@  target_read_btrace (struct btrace_target_info *tinfo,
 		    struct buffer *buffer,
 		    enum btrace_read_type type)
 {
-  if (the_target->read_btrace == nullptr)
-    error (_("Target does not support branch tracing."));
-
-  return (*the_target->read_btrace) (tinfo, buffer, type);
+  return the_target->pt->read_btrace (tinfo, buffer, type);
 }
 
 static inline int
 target_read_btrace_conf (struct btrace_target_info *tinfo,
 			 struct buffer *buffer)
 {
-  if (the_target->read_btrace_conf == nullptr)
-    error (_("Target does not support branch tracing."));
-
-  return (*the_target->read_btrace_conf) (tinfo, buffer);
+  return the_target->pt->read_btrace_conf (tinfo, buffer);
 }
 
 #define target_supports_range_stepping() \
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 84b6ea3e285..7fdc90feff1 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1858,10 +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, /* enable_btrace */
-  NULL, /* disable_btrace */
-  NULL, /* read_btrace */
-  NULL, /* read_btrace_conf */
   NULL, /* supports_range_stepping */
   NULL, /* pid_to_exec_file */
   NULL, /* multifs_open */