[PATCH 3/5] Refactor the NetBSD amd64 gdbserver support

Kamil Rytarowski
2020-09-23T04:26:33Z

Replace the pre-C++ construct of netbsd_target_ops, netbsd_regset_info
and netbsd_tdesc with C++ inheritance approach found in the Linux
gdbserver code. Add netbsd_amd64_target, that inherits from the
netbsd_process_target class and add proper singleton object for
the_netbsd_target, initialized from netbsd_amd64_target.

Call low_arch_setup () on post process creation, which sets machine
specific properties of the traced process.

Remove global singleton the_netbsd_target object from the generic
gdbserver code.

This refactoring introduces no functional change from the end-user
point of view.

gdbserver/ChangeLog:

* netbsd-amd64-low.cc (netbsd_x86_64_arch_setup): Remove.
(netbsd_target_regsets): Now const.
(the_low_target): Remove.
(class netbsd_amd64_target, the_netbsd_amd64_target)
(the_netbsd_target): Add.
* netbsd-low.cc (netbsd_process_target::post_create_inferior): Call
low_arch_setup ().
(netbsd_process_target::fetch_registers)
(netbsd_process_target::store_registers, initialize_low): Update.
(the_netbsd_target): Remove.
* netbsd-low.h (netbsd_target_regsets, netbsd_target_ops)
(the_low_target, netbsd_tdesc): Remove.
(netbsd_process_target::get_regs_info)
(netbsd_process_target::low_arch_setup): Add.
---
gdbserver/ChangeLog | 17 +++++++++++
gdbserver/netbsd-amd64-low.cc | 53 ++++++++++++++++++++++++-----------
gdbserver/netbsd-low.cc | 13 ++++-----
gdbserver/netbsd-low.h | 30 ++++++--------------
4 files changed, 67 insertions(+), 46 deletions(-)

diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index d47fcfd300a..5eb0eef82b2 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,3 +1,20 @@
+2020-09-22 Kamil Rytarowski <n54@gmx.com>
+
+ * netbsd-amd64-low.cc (netbsd_x86_64_arch_setup): Remove.
+ (netbsd_target_regsets): Now const.
+ (the_low_target): Remove.
+ (class netbsd_amd64_target, the_netbsd_amd64_target)
+ (the_netbsd_target): Add.
+ * netbsd-low.cc (netbsd_process_target::post_create_inferior): Call
+ low_arch_setup ().
+ (netbsd_process_target::fetch_registers)
+ (netbsd_process_target::store_registers, initialize_low): Update.
+ (the_netbsd_target): Remove.
+ * netbsd-low.h (netbsd_target_regsets, netbsd_target_ops)
+ (the_low_target, netbsd_tdesc): Remove.
+ (netbsd_process_target::get_regs_info)
+ (netbsd_process_target::low_arch_setup): Add.
+
2020-09-18 Tom Tromey <tromey@adacore.com>

* netbsd-low.h (class netbsd_process_target) <wait>: Update.
diff --git a/gdbserver/netbsd-amd64-low.cc b/gdbserver/netbsd-amd64-low.cc
index 9b8ea9b8aa6..2324bdbbfea 100644
--- a/gdbserver/netbsd-amd64-low.cc
+++ b/gdbserver/netbsd-amd64-low.cc
@@ -155,22 +155,9 @@ netbsd_x86_64_store_gregset (struct regcache *regcache, const char *buf)
netbsd_x86_64_supply_gp (AMD64_GS_REGNUM, GS);
}

-/* Implements the netbsd_target_ops.arch_setup routine. */
-
-static void
-netbsd_x86_64_arch_setup (void)
-{
- struct target_desc *tdesc
- = amd64_create_target_description (X86_XSTATE_SSE_MASK, false, false, false);
-
- init_target_desc (tdesc, amd64_expedite_regs);
-
- netbsd_tdesc = tdesc;
-}
-
/* Description of all the x86-netbsd register sets. */

-struct netbsd_regset_info netbsd_target_regsets[] =
+const static struct netbsd_regset_info netbsd_target_regsets[] =
{
/* General Purpose Registers. */
{PT_GETREGS, PT_SETREGS, sizeof (struct reg),
@@ -179,9 +166,41 @@ struct netbsd_regset_info netbsd_target_regsets[] =
{0, 0, -1, NULL, NULL }
};

-/* The netbsd_target_ops vector for x86-netbsd. */
+/* NetBSD target op definitions for the amd64 architecture. */

-struct netbsd_target_ops the_low_target =
+class netbsd_amd64_target : public netbsd_process_target
{
- netbsd_x86_64_arch_setup,
+protected:
+ const netbsd_regset_info *get_regs_info () override;
+
+ void low_arch_setup () override;
};
+
+/* Return the information to access registers. */
+
+const netbsd_regset_info *
+netbsd_amd64_target::get_regs_info ()
+{
+ return netbsd_target_regsets;
+}
+
+/* Architecture-specific setup for the current process. */
+
+void
+netbsd_amd64_target::low_arch_setup ()
+{
+ target_desc *tdesc
+ = amd64_create_target_description (X86_XSTATE_SSE_MASK, false, false, false);
+
+ init_target_desc (tdesc, amd64_expedite_regs);
+
+ current_process ()->tdesc = tdesc;
+}
+
+/* The singleton target ops object. */
+
+static netbsd_amd64_target the_netbsd_amd64_target;
+
+/* The NetBSD target ops object. */
+
+netbsd_process_target *the_netbsd_target = &the_netbsd_amd64_target;
diff --git a/gdbserver/netbsd-low.cc b/gdbserver/netbsd-low.cc
index 3eb2c0f25f6..58bfcad4fd9 100644
--- a/gdbserver/netbsd-low.cc
+++ b/gdbserver/netbsd-low.cc
@@ -114,6 +114,8 @@ netbsd_process_target::post_create_inferior ()
{
pid_t pid = current_process ()->pid;
netbsd_nat::enable_proc_events (pid);
+
+ low_arch_setup ();
}

/* Implement the attach target_ops method. */
@@ -504,7 +506,7 @@ netbsd_process_target::thread_alive (ptid_t ptid)
void
netbsd_process_target::fetch_registers (struct regcache *regcache, int regno)
{
- struct netbsd_regset_info *regset = netbsd_target_regsets;
+ const netbsd_regset_info *regset = get_regs_info();
ptid_t inferior_ptid = ptid_of (current_thread);

while (regset->size >= 0)
@@ -525,7 +527,7 @@ netbsd_process_target::fetch_registers (struct regcache *regcache, int regno)
void
netbsd_process_target::store_registers (struct regcache *regcache, int regno)
{
- struct netbsd_regset_info *regset = netbsd_target_regsets;
+ const netbsd_regset_info *regset = get_regs_info();
ptid_t inferior_ptid = ptid_of (current_thread);

while (regset->size >= 0)
@@ -1317,13 +1319,8 @@ netbsd_process_target::supports_read_auxv ()
return true;
}

-/* The NetBSD target ops object. */
-
-static netbsd_process_target the_netbsd_target;
-
void
initialize_low ()
{
- set_target_ops (&the_netbsd_target);
- the_low_target.arch_setup ();
+ set_target_ops (the_netbsd_target);
}
diff --git a/gdbserver/netbsd-low.h b/gdbserver/netbsd-low.h
index 96ad6d92474..c229a0f9f61 100644
--- a/gdbserver/netbsd-low.h
+++ b/gdbserver/netbsd-low.h
@@ -35,21 +35,6 @@ struct netbsd_regset_info
void (*store_function) (struct regcache *regcache, const char *buf);
};

-/* A list of regsets for the target being debugged, terminated by an entry
- where the size is negative.
-
- This list should be created by the target-specific code. */
-
-extern struct netbsd_regset_info netbsd_target_regsets[];
-
-/* The target-specific operations for NetBSD support. */
-
-struct netbsd_target_ops
-{
- /* Architecture-specific setup. */
- void (*arch_setup) ();
-};
-
/* Target ops definitions for a NetBSD target. */

class netbsd_process_target : public process_stratum_target
@@ -141,14 +126,17 @@ class netbsd_process_target : public process_stratum_target
const char *thread_name (ptid_t thread) override;

bool supports_catch_syscall () override;
-};

-/* The inferior's target description. This is a global because the
- NetBSD ports support neither bi-arch nor multi-process. */
+protected:
+ /* The architecture-specific "low" methods are listed below. */

-extern struct netbsd_target_ops the_low_target;
+ /* Return the information to access registers. */
+ virtual const netbsd_regset_info *get_regs_info () = 0;
+
+ /* Architecture-specific setup for the current process. */
+ virtual void low_arch_setup () = 0;
+};

-/* XXX: multilib */
-extern const struct target_desc *netbsd_tdesc;
+extern netbsd_process_target *the_netbsd_target;

#endif /* GDBSERVER_NETBSD_LOW_H */
--
2.28.0