Introduce process_stratum_target

This adds a base class that all process_stratum targets inherit from.

default_thread_address_space/default_thread_architecture only make
sense for process_stratum targets, so they are transformed to
process_stratum_target methods/overrides.

gdb/ChangeLog:
2018-11-30  Pedro Alves  <palves@redhat.com>

	* Makefile.in (COMMON_SFILES): Add process-stratum-target.c.
	* bsd-kvm.c: Include "process-stratum-target.h".
	(bsd_kvm_target): Now inherits from process_stratum_target.
	(bsd_kvm_target::bsd_kvm_target): Default it.
	* corelow.c: Include "process-stratum-target.h".
	(core_target): Now inherits from process_stratum_target.
	(core_target::core_target): Don't set to_stratum here.
	* inf-child.c (inf_child_target::inf_child_target): Delete.
	* inf-child.h: Include "process-stratum-target.h".
	(inf_child_target): Inherit from process_stratum_target.
	(inf_child_target) <inf_child_target>: Default it.
	<can_async_p, supports_non_stop, supports_disable_randomization>:
	Delete overrides.
	* process-stratum-target.c: New file.
	* process-stratum-target.h: New file.
	* remote-sim.c: Include "process-stratum-target.h".
	(gdbsim_target): Inherit from process_stratum_target.
	<gdbsim_target>: Default it.
	* remote.c: Include "process-stratum-target.h".
	(remote_target): Inherit from process_stratum_target.
	<remote_target>: Default it.
	* target.c (default_thread_address_space)
	(default_thread_architecture): Delete.
	* target.h (target_ops) <thread_architecture>: Now returns NULL by
	default.
	<thread_address_space>: Ditto.
	* test-target.h: Include "process-stratum-target.h" instead of
	"target.h".
	(test_target_ops): Inherit from process_stratum_target.
	<test_target_ops>: Default it.
	* tracefile.c (tracefile_target::tracefile_target): Delete.
	* tracefile.h: Include "process-stratum-target.h".
	(tracefile_target): Inherit from process_stratum_target.
	<tracefile_target>: Default it.
	* target-delegates.c: Regenerate.

16 files changed, 165 insertions, 82 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 49450e3..faed74b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,43 @@
 2018-11-30  Pedro Alves  <palves@redhat.com>
 
+	* Makefile.in (COMMON_SFILES): Add process-stratum-target.c.
+	* bsd-kvm.c: Include "process-stratum-target.h".
+	(bsd_kvm_target): Now inherits from process_stratum_target.
+	(bsd_kvm_target::bsd_kvm_target): Default it.
+	* corelow.c: Include "process-stratum-target.h".
+	(core_target): Now inherits from process_stratum_target.
+	(core_target::core_target): Don't set to_stratum here.
+	* inf-child.c (inf_child_target::inf_child_target): Delete.
+	* inf-child.h: Include "process-stratum-target.h".
+	(inf_child_target): Inherit from process_stratum_target.
+	(inf_child_target) <inf_child_target>: Default it.
+	<can_async_p, supports_non_stop, supports_disable_randomization>:
+	Delete overrides.
+	* process-stratum-target.c: New file.
+	* process-stratum-target.h: New file.
+	* remote-sim.c: Include "process-stratum-target.h".
+	(gdbsim_target): Inherit from process_stratum_target.
+	<gdbsim_target>: Default it.
+	* remote.c: Include "process-stratum-target.h".
+	(remote_target): Inherit from process_stratum_target.
+	<remote_target>: Default it.
+	* target.c (default_thread_address_space)
+	(default_thread_architecture): Delete.
+	* target.h (target_ops) <thread_architecture>: Now returns NULL by
+	default.
+	<thread_address_space>: Ditto.
+	* test-target.h: Include "process-stratum-target.h" instead of
+	"target.h".
+	(test_target_ops): Inherit from process_stratum_target.
+	<test_target_ops>: Default it.
+	* tracefile.c (tracefile_target::tracefile_target): Delete.
+	* tracefile.h: Include "process-stratum-target.h".
+	(tracefile_target): Inherit from process_stratum_target.
+	<tracefile_target>: Default it.
+	* target-delegates.c: Regenerate.
+
+2018-11-30  Pedro Alves  <palves@redhat.com>
+
 	* Makefile.in (COMMON_SFILES): Add test-target.c.
 	* gdbarch-selftests.c: Include "test-target.h".
 	* regcache.c: Include "test-target.h".
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 7ec3c0a..1099d71 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1075,6 +1075,7 @@ COMMON_SFILES = \
 	parse.c \
 	printcmd.c \
 	probe.c \
+	process-stratum-target.c \
 	producer.c \
 	progspace.c \
 	progspace-and-thread.c \
diff --git a/gdb/bsd-kvm.c b/gdb/bsd-kvm.c
index af8305f..977baf9 100644
--- a/gdb/bsd-kvm.c
+++ b/gdb/bsd-kvm.c
@@ -24,6 +24,7 @@
 #include "frame.h"
 #include "regcache.h"
 #include "target.h"
+#include "process-stratum-target.h"
 #include "value.h"
 #include "gdbcore.h"
 #include "inferior.h"          /* for get_exec_file */
@@ -71,11 +72,10 @@ static const target_info bsd_kvm_target_info = {
 Optionally specify the filename of a core dump.")
 };
 
-class bsd_kvm_target final : public target_ops
+class bsd_kvm_target final : public process_stratum_target
 {
 public:
-  bsd_kvm_target ()
-  { this->to_stratum = process_stratum; }
+  bsd_kvm_target () = default;
 
   const target_info &info () const override
   { return bsd_kvm_target_info; }
diff --git a/gdb/corelow.c b/gdb/corelow.c
index 72f2807..deabf84 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -31,6 +31,7 @@
 #include "command.h"
 #include "bfd.h"
 #include "target.h"
+#include "process-stratum-target.h"
 #include "gdbcore.h"
 #include "gdbthread.h"
 #include "regcache.h"
@@ -61,7 +62,7 @@ static const target_info core_target_info = {
   N_("Use a core file as a target.  Specify the filename of the core file.")
 };
 
-class core_target final : public target_ops
+class core_target final : public process_stratum_target
 {
 public:
   core_target ();
@@ -132,8 +133,6 @@ private: /* per-core data */
 
 core_target::core_target ()
 {
-  to_stratum = process_stratum;
-
   m_core_gdbarch = gdbarch_from_bfd (core_bfd);
 
   /* Find a suitable core file handler to munch on core_bfd */
diff --git a/gdb/inf-child.c b/gdb/inf-child.c
index 44aa2f6..8cdfa05 100644
--- a/gdb/inf-child.c
+++ b/gdb/inf-child.c
@@ -439,11 +439,6 @@ inf_child_target::can_use_agent ()
   return agent_loaded_p ();
 }
 
-inf_child_target::inf_child_target ()
-{
-  this->to_stratum = process_stratum;
-}
-
 /* See inf-child.h.  */
 
 void
diff --git a/gdb/inf-child.h b/gdb/inf-child.h
index 98969bc..d301d39 100644
--- a/gdb/inf-child.h
+++ b/gdb/inf-child.h
@@ -21,15 +21,16 @@
 #define INF_CHILD_H
 
 #include "target.h"
+#include "process-stratum-target.h"
 
 /* A prototype child target.  The client can override it with local
    methods.  */
 
 class inf_child_target
-  : public memory_breakpoint_target<target_ops>
+  : public memory_breakpoint_target<process_stratum_target>
 {
 public:
-  inf_child_target ();
+  inf_child_target () = default;
   ~inf_child_target () override = 0;
 
   const target_info &info () const override;
@@ -69,12 +70,6 @@ public:
 
   void post_attach (int) override;
 
-  /* We must default these because they must be implemented by any
-     target that can run.  */
-  bool can_async_p ()  override { return false; }
-  bool supports_non_stop ()  override { return false; }
-  bool supports_disable_randomization () override { return false; }
-
   char *pid_to_exec_file (int pid) override;
 
   bool has_all_memory () override;
diff --git a/gdb/process-stratum-target.c b/gdb/process-stratum-target.c
new file mode 100644
index 0000000..9ce8d3d
--- /dev/null
+++ b/gdb/process-stratum-target.c
@@ -0,0 +1,49 @@
+/* Abstract base class inherited by all process_stratum targets
+
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "process-stratum-target.h"
+#include "inferior.h"
+
+process_stratum_target::~process_stratum_target ()
+{
+}
+
+struct address_space *
+process_stratum_target::thread_address_space (ptid_t ptid)
+{
+  /* Fall-back to the "main" address space of the inferior.  */
+  inferior *inf = find_inferior_ptid (ptid);
+
+  if (inf == NULL || inf->aspace == NULL)
+    internal_error (__FILE__, __LINE__,
+		    _("Can't determine the current "
+		      "address space of thread %s\n"),
+		    target_pid_to_str (ptid));
+
+  return inf->aspace;
+}
+
+struct gdbarch *
+process_stratum_target::thread_architecture (ptid_t ptid)
+{
+  inferior *inf = find_inferior_ptid (ptid);
+  gdb_assert (inf != NULL);
+  return inf->gdbarch;
+}
diff --git a/gdb/process-stratum-target.h b/gdb/process-stratum-target.h
new file mode 100644
index 0000000..0a799f7
--- /dev/null
+++ b/gdb/process-stratum-target.h
@@ -0,0 +1,51 @@
+/* Abstract base class inherited by all process_stratum targets
+
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef PROCESS_STRATUM_TARGET_H
+#define PROCESS_STRATUM_TARGET_H
+
+#include "target.h"
+
+/* Abstract base class inherited by all process_stratum targets.  */
+
+class process_stratum_target : public target_ops
+{
+public:
+  process_stratum_target ()
+  {
+    to_stratum = process_stratum;
+  }
+
+  ~process_stratum_target () override = 0;
+
+  /* We must default these because they must be implemented by any
+     target that can run.  */
+  bool can_async_p () override { return false; }
+  bool supports_non_stop () override { return false; }
+  bool supports_disable_randomization () override { return false; }
+
+  /* This default implementation returns the inferior's address
+     space.  */
+  struct address_space *thread_address_space (ptid_t ptid) override;
+
+  /* This default implementation always returns target_gdbarch ().  */
+  struct gdbarch *thread_architecture (ptid_t ptid) override;
+};
+
+#endif /* !defined (PROCESS_STRATUM_TARGET_H) */
diff --git a/gdb/remote-sim.c b/gdb/remote-sim.c
index 63e4145..1ceecaa 100644
--- a/gdb/remote-sim.c
+++ b/gdb/remote-sim.c
@@ -31,6 +31,7 @@
 #include <setjmp.h>
 #include "terminal.h"
 #include "target.h"
+#include "process-stratum-target.h"
 #include "gdbcore.h"
 #include "gdb/callback.h"
 #include "gdb/remote-sim.h"
@@ -82,10 +83,9 @@ static const target_info gdbsim_target_info = {
 };
 
 struct gdbsim_target final
-  : public memory_breakpoint_target<target_ops>
+  : public memory_breakpoint_target<process_stratum_target>
 {
-  gdbsim_target ()
-  { to_stratum = process_stratum; }
+  gdbsim_target () = default;
 
   const target_info &info () const override
   { return gdbsim_target_info; }
diff --git a/gdb/remote.c b/gdb/remote.c
index 90b5dab..ae35bec 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -27,6 +27,7 @@
 #include "bfd.h"
 #include "symfile.h"
 #include "target.h"
+#include "process-stratum-target.h"
 /*#include "terminal.h" */
 #include "gdbcmd.h"
 #include "objfiles.h"
@@ -404,13 +405,10 @@ static const target_info remote_target_info = {
   remote_doc
 };
 
-class remote_target : public target_ops
+class remote_target : public process_stratum_target
 {
 public:
-  remote_target ()
-  {
-    to_stratum = process_stratum;
-  }
+  remote_target () = default;
   ~remote_target () override;
 
   const target_info &info () const override
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index eeb5057..1e70823 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -2808,7 +2808,7 @@ target_ops::thread_architecture (ptid_t arg0)
 struct gdbarch *
 dummy_target::thread_architecture (ptid_t arg0)
 {
-  return default_thread_architecture (this, arg0);
+  return NULL;
 }
 
 struct gdbarch *
@@ -2834,7 +2834,7 @@ target_ops::thread_address_space (ptid_t arg0)
 struct address_space *
 dummy_target::thread_address_space (ptid_t arg0)
 {
-  return default_thread_address_space (this, arg0);
+  return NULL;
 }
 
 struct address_space *
diff --git a/gdb/target.c b/gdb/target.c
index 7fad3a9..8905ce3 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -82,16 +82,10 @@ static int default_verify_memory (struct target_ops *self,
 				  const gdb_byte *data,
 				  CORE_ADDR memaddr, ULONGEST size);
 
-static struct address_space *default_thread_address_space
-     (struct target_ops *self, ptid_t ptid);
-
 static void tcomplain (void) ATTRIBUTE_NORETURN;
 
 static struct target_ops *find_default_run_target (const char *);
 
-static struct gdbarch *default_thread_architecture (struct target_ops *ops,
-						    ptid_t ptid);
-
 static int dummy_find_memory_regions (struct target_ops *self,
 				      find_memory_region_ftype ignore1,
 				      void *ignore2);
@@ -2567,22 +2561,6 @@ target_get_osdata (const char *type)
   return target_read_stralloc (t, TARGET_OBJECT_OSDATA, type);
 }
 
-static struct address_space *
-default_thread_address_space (struct target_ops *self, ptid_t ptid)
-{
-  struct inferior *inf;
-
-  /* Fall-back to the "main" address space of the inferior.  */
-  inf = find_inferior_ptid (ptid);
-
-  if (inf == NULL || inf->aspace == NULL)
-    internal_error (__FILE__, __LINE__,
-		    _("Can't determine the current "
-		      "address space of thread %s\n"),
-		    target_pid_to_str (ptid));
-
-  return inf->aspace;
-}
 
 /* Determine the current address space of thread PTID.  */
 
@@ -3180,14 +3158,6 @@ default_watchpoint_addr_within_range (struct target_ops *target,
   return addr >= start && addr < start + length;
 }
 
-static struct gdbarch *
-default_thread_architecture (struct target_ops *ops, ptid_t ptid)
-{
-  inferior *inf = find_inferior_ptid (ptid);
-  gdb_assert (inf != NULL);
-  return inf->gdbarch;
-}
-
 /* See target.h.  */
 
 target_ops *
diff --git a/gdb/target.h b/gdb/target.h
index e170bbc..36f8d5e 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -882,18 +882,13 @@ struct target_ops
        to_thread_architecture would return SPU, otherwise PPC32 or PPC64).
        This is architecture used to perform decr_pc_after_break adjustment,
        and also determines the frame architecture of the innermost frame.
-       ptrace operations need to operate according to target_gdbarch ().
-
-       The default implementation always returns target_gdbarch ().  */
+       ptrace operations need to operate according to target_gdbarch ().  */
     virtual struct gdbarch *thread_architecture (ptid_t)
-      TARGET_DEFAULT_FUNC (default_thread_architecture);
-
-    /* Determine current address space of thread PTID.
+      TARGET_DEFAULT_RETURN (NULL);
 
-       The default implementation always returns the inferior's
-       address space.  */
+    /* Determine current address space of thread PTID.  */
     virtual struct address_space *thread_address_space (ptid_t)
-      TARGET_DEFAULT_FUNC (default_thread_address_space);
+      TARGET_DEFAULT_RETURN (NULL);
 
     /* Target file operations.  */
 
diff --git a/gdb/test-target.h b/gdb/test-target.h
index b3170f8..1286fc1 100644
--- a/gdb/test-target.h
+++ b/gdb/test-target.h
@@ -20,7 +20,7 @@
 #ifndef TEST_TARGET_H
 #define TEST_TARGET_H
 
-#include "target.h"
+#include "process-stratum-target.h"
 
 #if GDB_SELF_TEST
 namespace selftests {
@@ -28,14 +28,10 @@ namespace selftests {
 /* A mock process_stratum target_ops that doesn't read/write registers
    anywhere.  */
 
-class test_target_ops : public target_ops
+class test_target_ops : public process_stratum_target
 {
 public:
-  test_target_ops ()
-    : target_ops {}
-  {
-    to_stratum = process_stratum;
-  }
+  test_target_ops () = default;
 
   const target_info &info () const override;
 
diff --git a/gdb/tracefile.c b/gdb/tracefile.c
index b367f6e..88e79f7 100644
--- a/gdb/tracefile.c
+++ b/gdb/tracefile.c
@@ -470,11 +470,6 @@ tracefile_target::get_trace_status (struct trace_status *ts)
   return -1;
 }
 
-tracefile_target::tracefile_target ()
-{
-  this->to_stratum = process_stratum;
-}
-
 void
 _initialize_tracefile (void)
 {
diff --git a/gdb/tracefile.h b/gdb/tracefile.h
index 47f8bee..3ae3e7d 100644
--- a/gdb/tracefile.h
+++ b/gdb/tracefile.h
@@ -3,6 +3,7 @@
 
 #include "tracepoint.h"
 #include "target.h"
+#include "process-stratum-target.h"
 
 struct trace_file_writer;
 
@@ -116,10 +117,10 @@ extern struct trace_file_writer *tfile_trace_file_writer_new (void);
 
 /* Base class for tracefile related targets.  */
 
-class tracefile_target : public target_ops
+class tracefile_target : public process_stratum_target
 {
 public:
-  tracefile_target ();
+  tracefile_target () = default;
 
   int get_trace_status (trace_status *ts) override;
   bool has_all_memory () override;