Python: Introduce gdb.Instruction class

This adds a generic instruction class to Python and has gdb.RecordInstruction
inherit from it.

gdb/python/py-instruction.c

@@ -0,0 +1,67 @@
+/* Python interface to instruction objects.
+
+   Copyright 2017 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 "py-instruction.h"
+
+/* See py-instruction.h.  */
+
+PyTypeObject py_insn_type = {
+  PyVarObject_HEAD_INIT (NULL, 0)
+};
+
+/* Python instruction object.  */
+
+typedef struct {
+  PyObject_HEAD
+} py_insn_obj;
+
+/* Getter function for gdb.Instruction attributes.  */
+
+static PyObject *
+py_insn_getter (PyObject *self, void *closure)
+{
+  return PyErr_Format (PyExc_NotImplementedError, _("Not implemented."));
+}
+
+/* Instruction members.  */
+
+static gdb_PyGetSetDef py_insn_getset[] =
+{
+  { "pc", py_insn_getter, NULL, "instruction address", NULL},
+  { "data", py_insn_getter, NULL, "instruction memory", NULL},
+  { "decoded", py_insn_getter, NULL, "decoded instruction", NULL},
+  { "size", py_insn_getter, NULL, "instruction size in bytes", NULL},
+  {NULL}
+};
+
+/* Sets up the gdb.Instruction type.  */
+
+int
+gdbpy_initialize_instruction (void)
+{
+  py_insn_type.tp_new = PyType_GenericNew;
+  py_insn_type.tp_flags = Py_TPFLAGS_DEFAULT;
+  py_insn_type.tp_basicsize = sizeof (py_insn_obj);
+  py_insn_type.tp_name = "gdb.Instruction";
+  py_insn_type.tp_doc = "GDB instruction object";
+  py_insn_type.tp_getset = py_insn_getset;
+
+  return PyType_Ready (&py_insn_type);
+}

gdb/python/py-instruction.h

@@ -0,0 +1,30 @@
+/* Python interface to instruction objects.
+
+   Copyright 2017 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 GDB_PY_INSTRUCTION_H
+#define GDB_PY_INSTRUCTION_H
+
+#include "python-internal.h"
+
+/* Python type object for the abstract gdb.Instruction class.  This class
+   contains getters for four elements: "pc" (int), "data" (buffer), "decode"
+   (str) and "size" (int) that must be overriden by sub classes.  */
+extern PyTypeObject py_insn_type;
+
+#endif /* GDB_PY_INSTRUCTION_H */

gdb/python/py-record.c

@@ -18,6 +18,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
+#include "py-instruction.h"
 #include "py-record.h"
 #include "py-record-btrace.h"
 #include "py-record-full.h"
@@ -561,6 +562,7 @@ gdbpy_initialize_record (void)
   recpy_insn_type.tp_getset = recpy_insn_getset;
   recpy_insn_type.tp_richcompare = recpy_element_richcompare;
   recpy_insn_type.tp_hash = recpy_element_hash;
+  recpy_insn_type.tp_base = &py_insn_type;
 
   recpy_func_type.tp_new = PyType_GenericNew;
   recpy_func_type.tp_flags = Py_TPFLAGS_DEFAULT;

gdb/python/python-internal.h

@@ -562,6 +562,8 @@ int gdbpy_initialize_values (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_frames (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_instruction (void)
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_btrace (void)
   CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
 int gdbpy_initialize_record (void)

gdb/python/python.c

@@ -1626,6 +1626,7 @@ do_start_initialization ()
       || gdbpy_initialize_values () < 0
       || gdbpy_initialize_frames () < 0
       || gdbpy_initialize_commands () < 0
+      || gdbpy_initialize_instruction () < 0
       || gdbpy_initialize_record () < 0
       || gdbpy_initialize_btrace () < 0
       || gdbpy_initialize_symbols () < 0