Add a new method 'disassemble' to gdb.Architecture class.

* python/py-arch.c (archpy_disassmble): Implementation of the
	new method gdb.Architecture.disassemble.
	(arch_object_methods): Add entry for the new method.

	* doc/gdb.texinfo (Architectures In Python): Add description
	about the new method gdb.Architecture.disassemble.

	* testsuite/gdb.python/py-arch.c: New test case
	* testsuite/gdb.python/py-arch.exp: New tests to test
	gdb.Architecture.disassemble
	* testsuite/gdb.python/Makefile.in: Add py-arch to the list of
	EXECUTABLES.

gdb/python/py-arch.c

@@ -20,6 +20,7 @@
 #include "defs.h"
 #include "gdbarch.h"
 #include "arch-utils.h"
+#include "disasm.h"
 #include "python-internal.h"
 
 typedef struct arch_object_type_object {
@@ -86,6 +87,145 @@ archpy_name (PyObject *self, PyObject *args)
   return py_name;
 }
 
+/* Implementation of
+   gdb.Architecture.disassemble (self, start_pc [, end_pc [,count]]) -> List.
+   Returns a list of instructions in a memory address range.  Each instruction
+   in the list is a Python dict object.
+*/
+
+static PyObject *
+archpy_disassemble (PyObject *self, PyObject *args, PyObject *kw)
+{
+  static char *keywords[] = { "start_pc", "end_pc", "count", NULL };
+  CORE_ADDR start, end = 0;
+  CORE_ADDR pc;
+  gdb_py_ulongest start_temp;
+  long count = 0, i;
+  PyObject *result_list, *end_obj = NULL, *count_obj = NULL;
+  struct gdbarch *gdbarch = arch_object_to_gdbarch (self);
+
+  if (!PyArg_ParseTupleAndKeywords (args, kw, GDB_PY_LLU_ARG "|OO", keywords,
+                                    &start_temp, &end_obj, &count_obj))
+    return NULL;
+
+  start = start_temp;
+  if (end_obj)
+    {
+      if (PyObject_TypeCheck (end_obj, &PyInt_Type))
+        /* If the end_pc value is specified without a trailing 'L', end_obj will
+           be an integer and not a long integer.  */
+        end = PyInt_AsLong (end_obj);
+      else if (PyObject_TypeCheck (end_obj, &PyLong_Type))
+        end = PyLong_AsUnsignedLongLong (end_obj);
+      else
+        {
+          Py_DECREF (end_obj);
+          Py_XDECREF (count_obj);
+          PyErr_SetString (PyExc_TypeError,
+                           _("Argument 'end_pc' should be a (long) integer."));
+
+          return NULL;
+        }
+
+      if (end < start)
+        {
+          Py_DECREF (end_obj);
+          Py_XDECREF (count_obj);
+          PyErr_SetString (PyExc_ValueError,
+                           _("Argument 'end_pc' should be greater than or "
+                             "equal to the argument 'start_pc'."));
+
+          return NULL;
+        }
+    }
+  if (count_obj)
+    {
+      count = PyInt_AsLong (count_obj);
+      if (PyErr_Occurred () || count < 0)
+        {
+          Py_DECREF (count_obj);
+          Py_XDECREF (end_obj);
+          PyErr_SetString (PyExc_TypeError,
+                           _("Argument 'count' should be an non-negative "
+                             "integer."));
+
+          return NULL;
+        }
+    }
+
+  result_list = PyList_New (0);
+  if (result_list == NULL)
+    return NULL;
+
+  for (pc = start, i = 0;
+       /* All args are specified.  */
+       (end_obj && count_obj && pc <= end && i < count)
+       /* end_pc is specified, but no count.  */
+       || (end_obj && count_obj == NULL && pc <= end)
+       /* end_pc is not specified, but a count is.  */
+       || (end_obj == NULL && count_obj && i < count)
+       /* Both end_pc and count are not specified.  */
+       || (end_obj == NULL && count_obj == NULL && pc == start);)
+    {
+      int insn_len = 0;
+      char *as = NULL;
+      struct ui_file *memfile = mem_fileopen ();
+      PyObject *insn_dict = PyDict_New ();
+      volatile struct gdb_exception except;
+
+      if (insn_dict == NULL)
+        {
+          Py_DECREF (result_list);
+          ui_file_delete (memfile);
+
+          return NULL;
+        }
+      if (PyList_Append (result_list, insn_dict))
+        {
+          Py_DECREF (result_list);
+          Py_DECREF (insn_dict);
+          ui_file_delete (memfile);
+
+          return NULL;  /* PyList_Append Sets the exception.  */
+        }
+
+      TRY_CATCH (except, RETURN_MASK_ALL)
+        {
+          insn_len = gdb_print_insn (gdbarch, pc, memfile, NULL);
+        }
+      if (except.reason < 0)
+        {
+          Py_DECREF (result_list);
+          ui_file_delete (memfile);
+
+          return gdbpy_convert_exception (except);
+        }
+
+      as = ui_file_xstrdup (memfile, NULL);
+      if (PyDict_SetItemString (insn_dict, "addr",
+                                gdb_py_long_from_ulongest (pc))
+          || PyDict_SetItemString (insn_dict, "asm",
+                                   PyString_FromString (*as ? as : "<unknown>"))
+          || PyDict_SetItemString (insn_dict, "length",
+                                   PyInt_FromLong (insn_len)))
+        {
+          Py_DECREF (result_list);
+
+          ui_file_delete (memfile);
+          xfree (as);
+
+          return NULL;
+        }
+
+      pc += insn_len;
+      i++;
+      ui_file_delete (memfile);
+      xfree (as);
+    }
+
+  return result_list;
+}
+
 /* Initializes the Architecture class in the gdb module.  */
 
 void
@@ -105,6 +245,11 @@ static PyMethodDef arch_object_methods [] = {
   { "name", archpy_name, METH_NOARGS,
     "name () -> String.\n\
 Return the name of the architecture as a string value." },
+  { "disassemble", (PyCFunction) archpy_disassemble,
+    METH_VARARGS | METH_KEYWORDS,
+    "disassemble (start_pc [, end_pc [, count]]) -> List.\n\
+Return a list of at most COUNT disassembled instructions from START_PC to\n\
+END_PC." },
   {NULL}  /* Sentinel */
 };