+2020-04-02  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+       Remove the 'install_fast_tracepoint_jump_pad' and
+       'get_min_fast_tracepoint_insn_len' linux target ops to let the
+       concrete linux target define the ops by overriding the declarations
+       of process_stratum_target.
+
+       * linux-low.h (struct linux_target_ops): Remove the ops.
+       (class linux_process_target) <supports_fast_tracepoints>
+       <install_fast_tracepoint_jump_pad>
+       <get_min_fast_tracepoint_insn_len>: Remove.
+       * linux-low.cc (linux_process_target::supports_fast_tracepoints)
+       (linux_process_target::install_fast_tracepoint_jump_pad)
+       (linux_process_target::get_min_fast_tracepoint_insn_len): Remove.
+       * linux-x86-low.cc (class x86_target) <supports_fast_tracepoints>
+       <install_fast_tracepoint_jump_pad>
+       <get_min_fast_tracepoint_insn_len>: Declare.
+       (x86_target::supports_fast_tracepoints): Define.
+       (x86_install_fast_tracepoint_jump_pad): Turn into...
+       (x86_target::install_fast_tracepoint_jump_pad): ...this.
+       (x86_get_min_fast_tracepoint_insn_len): Turn into...
+       (x86_target::get_min_fast_tracepoint_insn_len): ...this.
+       (the_low_target): Remove the op fields.
+       * linux-aarch64-low.cc (class aarch64_target)
+       <supports_fast_tracepoints>
+       <install_fast_tracepoint_jump_pad>
+       <get_min_fast_tracepoint_insn_len>: Declare.
+       (aarch64_target::supports_fast_tracepoints): Define.
+       (aarch64_install_fast_tracepoint_jump_pad): Turn into...
+       (aarch64_target::install_fast_tracepoint_jump_pad): ...this.
+       (aarch64_get_min_fast_tracepoint_insn_len): Turn into...
+       (aarch64_target::get_min_fast_tracepoint_insn_len): ...this.
+       (the_low_target): Remove the op fields.
+       * linux-ppc-low.cc (class ppc_target) <supports_fast_tracepoints>
+       <install_fast_tracepoint_jump_pad>
+       <get_min_fast_tracepoint_insn_len>: Declare.
+       (ppc_target::supports_fast_tracepoints): Define.
+       (ppc_install_fast_tracepoint_jump_pad): Turn into...
+       (ppc_target::install_fast_tracepoint_jump_pad): ...this.
+       (ppc_get_min_fast_tracepoint_insn_len): Turn into...
+       (ppc_target::get_min_fast_tracepoint_insn_len): ...this.
+       (the_low_target): Remove the op fields.
+       * linux-s390-low.cc (class s390_target) <supports_fast_tracepoints>
+       <install_fast_tracepoint_jump_pad>
+       <get_min_fast_tracepoint_insn_len>: Declare.
+       (s390_target::supports_fast_tracepoints): Define.
+       (s390_install_fast_tracepoint_jump_pad): Turn into...
+       (s390_target::install_fast_tracepoint_jump_pad): ...this.
+       (s390_get_min_fast_tracepoint_insn_len): Turn into...
+       (s390_target::get_min_fast_tracepoint_insn_len): ...this.
+       (the_low_target): Remove the op fields.
+       * linux-arm-low.cc (the_low_target): Remove the op fields.
+       * linux-bfin-low.cc (the_low_target): Ditto.
+       * linux-crisv32-low.cc (the_low_target): Ditto.
+       * linux-m32r-low.cc (the_low_target): Ditto.
+       * linux-m68k-low.cc (the_low_target): Ditto.
+       * linux-sh-low.cc (the_low_target): Ditto.
+       * linux-tic6x-low.cc (the_low_target): Ditto.
+       * linux-tile-low.cc (the_low_target): Ditto.
+       * linux-xtensa-low.cc (the_low_target): Ditto.
+
 2020-04-02  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
 
        Turn the 'get_thread_area' linux target op into a method of
 
 
   bool supports_tracepoints () override;
 
+  bool supports_fast_tracepoints () override;
+
+  int install_fast_tracepoint_jump_pad
+    (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+     CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+     CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+     unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+     CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+     char *err) override;
+
+  int get_min_fast_tracepoint_insn_len () override;
+
 protected:
 
   void low_arch_setup () override;
   aarch64_ftrace_insn_reloc_others,
 };
 
-/* Implementation of linux_target_ops method
+bool
+aarch64_target::supports_fast_tracepoints ()
+{
+  return true;
+}
+
+/* Implementation of target ops method
    "install_fast_tracepoint_jump_pad".  */
 
-static int
-aarch64_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
-                                         CORE_ADDR tpaddr,
-                                         CORE_ADDR collector,
-                                         CORE_ADDR lockaddr,
-                                         ULONGEST orig_size,
-                                         CORE_ADDR *jump_entry,
-                                         CORE_ADDR *trampoline,
-                                         ULONGEST *trampoline_size,
-                                         unsigned char *jjump_pad_insn,
-                                         ULONGEST *jjump_pad_insn_size,
-                                         CORE_ADDR *adjusted_insn_addr,
-                                         CORE_ADDR *adjusted_insn_addr_end,
-                                         char *err)
+int
+aarch64_target::install_fast_tracepoint_jump_pad
+  (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+   CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+   CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+   unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+   CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+   char *err)
 {
   uint32_t buf[256];
   uint32_t *p = buf;
   return &aarch64_emit_ops_impl;
 }
 
-/* Implementation of linux_target_ops method
+/* Implementation of target ops method
    "get_min_fast_tracepoint_insn_len".  */
 
-static int
-aarch64_get_min_fast_tracepoint_insn_len (void)
+int
+aarch64_target::get_min_fast_tracepoint_insn_len ()
 {
   return 4;
 }
 
 struct linux_target_ops the_low_target =
 {
-  aarch64_install_fast_tracepoint_jump_pad,
   aarch64_emit_ops,
-  aarch64_get_min_fast_tracepoint_insn_len,
   aarch64_supports_range_stepping,
   aarch64_supports_hardware_single_step,
   aarch64_get_syscall_trapinfo,
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   arm_supports_hardware_single_step,
   arm_get_syscall_trapinfo,
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   bfin_supports_hardware_single_step,
 };
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   cris_supports_hardware_single_step,
 };
 
     target_unpause_all (true);
 }
 
-bool
-linux_process_target::supports_fast_tracepoints ()
-{
-  return the_low_target.install_fast_tracepoint_jump_pad != nullptr;
-}
-
-int
-linux_process_target::install_fast_tracepoint_jump_pad
-  (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
-   CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
-   CORE_ADDR *trampoline, ULONGEST *trampoline_size,
-   unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
-   CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
-   char *err)
-{
-  return (*the_low_target.install_fast_tracepoint_jump_pad)
-    (tpoint, tpaddr, collector, lockaddr, orig_size,
-     jump_entry, trampoline, trampoline_size,
-     jjump_pad_insn, jjump_pad_insn_size,
-     adjusted_insn_addr, adjusted_insn_addr_end,
-     err);
-}
-
 emit_ops *
 linux_process_target::emit_ops ()
 {
     return NULL;
 }
 
-int
-linux_process_target::get_min_fast_tracepoint_insn_len ()
-{
-  return (*the_low_target.get_min_fast_tracepoint_insn_len) ();
-}
-
 /* Extract &phdr and num_phdr in the inferior.  Return 0 on success.  */
 
 static int
 
 
 struct linux_target_ops
 {
-  /* Install a fast tracepoint jump pad.  See target.h for
-     comments.  */
-  int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
-                                          CORE_ADDR collector,
-                                          CORE_ADDR lockaddr,
-                                          ULONGEST orig_size,
-                                          CORE_ADDR *jump_entry,
-                                          CORE_ADDR *trampoline,
-                                          ULONGEST *trampoline_size,
-                                          unsigned char *jjump_pad_insn,
-                                          ULONGEST *jjump_pad_insn_size,
-                                          CORE_ADDR *adjusted_insn_addr,
-                                          CORE_ADDR *adjusted_insn_addr_end,
-                                          char *err);
-
   /* Return the bytecode operations vector for the current inferior.
      Returns NULL if bytecode compilation is not supported.  */
   struct emit_ops *(*emit_ops) (void);
 
-  /* Return the minimum length of an instruction that can be safely overwritten
-     for use as a fast tracepoint.  */
-  int (*get_min_fast_tracepoint_insn_len) (void);
-
   /* Returns true if the low target supports range stepping.  */
   int (*supports_range_stepping) (void);
 
 
   void stabilize_threads () override;
 
-  bool supports_fast_tracepoints () override;
-
-  int install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
-                                       CORE_ADDR tpaddr,
-                                       CORE_ADDR collector,
-                                       CORE_ADDR lockaddr,
-                                       ULONGEST orig_size,
-                                       CORE_ADDR *jump_entry,
-                                       CORE_ADDR *trampoline,
-                                       ULONGEST *trampoline_size,
-                                       unsigned char *jjump_pad_insn,
-                                       ULONGEST *jjump_pad_insn_size,
-                                       CORE_ADDR *adjusted_insn_addr,
-                                       CORE_ADDR *adjusted_insn_addr_end,
-                                       char *err) override;
-
-  int get_min_fast_tracepoint_insn_len () override;
-
   struct emit_ops *emit_ops () override;
 
   bool supports_disable_randomization () override;
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   m32r_supports_hardware_single_step,
 };
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   m68k_supports_hardware_single_step,
 };
 
 
   bool supports_tracepoints () override;
 
+  bool supports_fast_tracepoints () override;
+
+  int install_fast_tracepoint_jump_pad
+    (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+     CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+     CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+     unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+     CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+     char *err) override;
+
+  int get_min_fast_tracepoint_insn_len () override;
+
 protected:
 
   void low_arch_setup () override;
   *to += 4;
 }
 
+bool
+ppc_target::supports_fast_tracepoints ()
+{
+  return true;
+}
+
 /* Implement install_fast_tracepoint_jump_pad of target_ops.
    See target.h for details.  */
 
-static int
-ppc_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
-                                     CORE_ADDR collector,
-                                     CORE_ADDR lockaddr,
-                                     ULONGEST orig_size,
-                                     CORE_ADDR *jump_entry,
-                                     CORE_ADDR *trampoline,
-                                     ULONGEST *trampoline_size,
-                                     unsigned char *jjump_pad_insn,
-                                     ULONGEST *jjump_pad_insn_size,
-                                     CORE_ADDR *adjusted_insn_addr,
-                                     CORE_ADDR *adjusted_insn_addr_end,
-                                     char *err)
+int
+ppc_target::install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
+                                             CORE_ADDR tpaddr,
+                                             CORE_ADDR collector,
+                                             CORE_ADDR lockaddr,
+                                             ULONGEST orig_size,
+                                             CORE_ADDR *jump_entry,
+                                             CORE_ADDR *trampoline,
+                                             ULONGEST *trampoline_size,
+                                             unsigned char *jjump_pad_insn,
+                                             ULONGEST *jjump_pad_insn_size,
+                                             CORE_ADDR *adjusted_insn_addr,
+                                             CORE_ADDR *adjusted_insn_addr_end,
+                                             char *err)
 {
   uint32_t buf[256];
   uint32_t *p = buf;
 
 /* Returns the minimum instruction length for installing a tracepoint.  */
 
-static int
-ppc_get_min_fast_tracepoint_insn_len (void)
+int
+ppc_target::get_min_fast_tracepoint_insn_len ()
 {
   return 4;
 }
 }
 
 struct linux_target_ops the_low_target = {
-  ppc_install_fast_tracepoint_jump_pad,
   ppc_emit_ops,
-  ppc_get_min_fast_tracepoint_insn_len,
   NULL, /* supports_range_stepping */
   ppc_supports_hardware_single_step,
   NULL, /* get_syscall_trapinfo */
 
 
   bool supports_tracepoints () override;
 
+  bool supports_fast_tracepoints () override;
+
+  int install_fast_tracepoint_jump_pad
+    (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+     CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+     CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+     unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+     CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+     char *err) override;
+
+  int get_min_fast_tracepoint_insn_len () override;
+
   void low_collect_ptrace_register (regcache *regcache, int regno,
                                    char *buf) override;
 
   return 0;
 }
 
-/* Implementation of linux_target_ops method
+bool
+s390_target::supports_fast_tracepoints ()
+{
+  return true;
+}
+
+/* Implementation of target ops method
    "install_fast_tracepoint_jump_pad".  */
 
-static int
-s390_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
-                                      CORE_ADDR tpaddr,
-                                      CORE_ADDR collector,
-                                      CORE_ADDR lockaddr,
-                                      ULONGEST orig_size,
-                                      CORE_ADDR *jump_entry,
-                                      CORE_ADDR *trampoline,
-                                      ULONGEST *trampoline_size,
-                                      unsigned char *jjump_pad_insn,
-                                      ULONGEST *jjump_pad_insn_size,
-                                      CORE_ADDR *adjusted_insn_addr,
-                                      CORE_ADDR *adjusted_insn_addr_end,
-                                      char *err)
+int
+s390_target::install_fast_tracepoint_jump_pad
+  (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+   CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+   CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+   unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+   CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+   char *err)
 {
   int i;
   int64_t loffset;
   return 0;
 }
 
-/* Implementation of linux_target_ops method
+/* Implementation of target ops method
    "get_min_fast_tracepoint_insn_len".  */
 
-static int
-s390_get_min_fast_tracepoint_insn_len (void)
+int
+s390_target::get_min_fast_tracepoint_insn_len ()
 {
   /* We only support using 6-byte jumps to reach the tracepoint code.
      If the tracepoint buffer were allocated sufficiently close (64kiB)
 }
 
 struct linux_target_ops the_low_target = {
-  s390_install_fast_tracepoint_jump_pad,
   s390_emit_ops,
-  s390_get_min_fast_tracepoint_insn_len,
   NULL, /* supports_range_stepping */
   s390_supports_hardware_single_step,
   NULL, /* get_syscall_trapinfo */
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   sh_supports_hardware_single_step,
 };
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   tic6x_supports_hardware_single_step,
 };
 
 
 struct linux_target_ops the_low_target =
 {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   tile_supports_hardware_single_step,
 };
 
 
   bool supports_tracepoints () override;
 
+  bool supports_fast_tracepoints () override;
+
+  int install_fast_tracepoint_jump_pad
+    (CORE_ADDR tpoint, CORE_ADDR tpaddr, CORE_ADDR collector,
+     CORE_ADDR lockaddr, ULONGEST orig_size, CORE_ADDR *jump_entry,
+     CORE_ADDR *trampoline, ULONGEST *trampoline_size,
+     unsigned char *jjump_pad_insn, ULONGEST *jjump_pad_insn_size,
+     CORE_ADDR *adjusted_insn_addr, CORE_ADDR *adjusted_insn_addr_end,
+     char *err) override;
+
+  int get_min_fast_tracepoint_insn_len () override;
+
 protected:
 
   void low_arch_setup () override;
   return 0;
 }
 
-static int
-x86_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
-                                     CORE_ADDR collector,
-                                     CORE_ADDR lockaddr,
-                                     ULONGEST orig_size,
-                                     CORE_ADDR *jump_entry,
-                                     CORE_ADDR *trampoline,
-                                     ULONGEST *trampoline_size,
-                                     unsigned char *jjump_pad_insn,
-                                     ULONGEST *jjump_pad_insn_size,
-                                     CORE_ADDR *adjusted_insn_addr,
-                                     CORE_ADDR *adjusted_insn_addr_end,
-                                     char *err)
+bool
+x86_target::supports_fast_tracepoints ()
+{
+  return true;
+}
+
+int
+x86_target::install_fast_tracepoint_jump_pad (CORE_ADDR tpoint,
+                                             CORE_ADDR tpaddr,
+                                             CORE_ADDR collector,
+                                             CORE_ADDR lockaddr,
+                                             ULONGEST orig_size,
+                                             CORE_ADDR *jump_entry,
+                                             CORE_ADDR *trampoline,
+                                             ULONGEST *trampoline_size,
+                                             unsigned char *jjump_pad_insn,
+                                             ULONGEST *jjump_pad_insn_size,
+                                             CORE_ADDR *adjusted_insn_addr,
+                                             CORE_ADDR *adjusted_insn_addr_end,
+                                             char *err)
 {
 #ifdef __x86_64__
   if (is_64bit_tdesc ())
 /* Return the minimum instruction length for fast tracepoints on x86/x86-64
    architectures.  */
 
-static int
-x86_get_min_fast_tracepoint_insn_len (void)
+int
+x86_target::get_min_fast_tracepoint_insn_len ()
 {
   static int warned_about_fast_tracepoints = 0;
 
 
 struct linux_target_ops the_low_target =
 {
-  x86_install_fast_tracepoint_jump_pad,
   x86_emit_ops,
-  x86_get_min_fast_tracepoint_insn_len,
   x86_supports_range_stepping,
   x86_supports_hardware_single_step,
   x86_get_syscall_trapinfo,
 
 }
 
 struct linux_target_ops the_low_target = {
-  NULL, /* install_fast_tracepoint_jump_pad */
   NULL, /* emit_ops */
-  NULL, /* get_min_fast_tracepoint_insn_len */
   NULL, /* supports_range_stepping */
   xtensa_supports_hardware_single_step,
 };