Add support for Python 3.

* NEWS: Mention Python 3 support.
* varobj.c (value_get_print_value): Use
python_string_to_target_string.
* python/py-block.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
* python/py-breakpoint.c: Ditto.
* python/py-cmd.c:  Ditto.
* python/py-event.c: Ditto.
* python/py-event.h: Ditto.
* python/py-evtregistry.c: Ditto.
* python/py-finishbreakpoint.c: Ditto.
* python/py-frame.c: Ditto.
* python/py-function.c: Ditto.
* python/py-infthread.c: Ditto.
* python/py-lazy-string.c: Ditto.
* python/py-progspace.c: Ditto.
* /python/py-symbol.c: Ditto.
* python/py-evts.c:  (gdbpy_initialize_py_events): Add module
initialization for Python 3.
* python/py-inferior.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(infpy_read_memory): Return memoryview object if Python 3.
(infpy_write_memory): Use "s*" operand parsing code for Python 3.
(infpy_search_memory): Ditto.
(get_buffer): New function for Python 3.
* python/py-objfile.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(objfpy_dealloc): Use Py_TYPE to call tp_free.
* python/py-param.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(get_attr): Use PyUnicode_CompareWithASCIIString if Python 3.
(set_attr): Ditto.
* python/py-prettyprint.c (print_string_repr): use PyBytes methods
instead of PyString methods if Python 3.
(print_children): Skip push_dummy_python_frame call if Python 3.
* python/py-symtab.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(salpy_dealloc): Use Py_TYPE to call tp_free.
* python/py-type.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(field_dealloc): Use Py_TYPE to call tp_free.
(typy_dealloc): Ditto.
(type_object_as_number): Adjust struct initializations for
differences in layout for Python 2 vs. Python 3.
* python/py-utils.c (python_string_to_unicode): Omit non-Unicode
string case for Python 3.
(unicode_to_encoded_python_string): Shorten code (no functional
change).
(python_string_to_target_python_string): Comment that in Python 3
returned value is a Python "bytes" type.
(gdbpy_is_string): Omit non-Unicode string check in Python 3.
(gdb_py_object_from_longest): Omit non-long integer case in Python
3.
(gdb_py_object_from_ulongest): Ditto.
* python/py-value.c: Use PyVarObject_HEAD_INIT in initialization
of type objects.
(valpy_dealloc): Use Py_TYPE to call tp_free.
(valpy_int): Omit function if Python 3.
(convert_value_from_python): Use "%S" format (Python object as a
string) if Python 3.
(value_object_as_number): Adjust struct initializations for
differences in layout for Python 2 vs. Python 3.
* python/python-config.py: Adjust syntax for Python 3
compatibility.
Include "sys.abiflags" string as part of python library name, if
that attribute exists (Python 3).
* python/python-internal.h (IS_PY3): Define if Python 3.
(Py_TPFLAGS_HAVE_ITER, Py_TPFLAGS_CHECKTYPES): Define with
placeholder value if Python 3.
(PyInt_Check, PyInt_FromLong, PyInt_AsLong, PyString_FromString,
PyString_Decode, PyString_FromFormat, PyString_Check): Define as
analogous Python 3 API function if Python 3.
(PyVarObject_HEAD_INIT): Define if not already defined.
(Py_TYPE): Ditto.
* python/python.c (eval_python_command): Omit Py_FlushLine call if
Python 3.
Check return values of all Python API calls for error.
Supply dummy "python" and "python-interactive" commands if Python
initialization failed.
(_initialize_python): Convert argc to wchar_t** if Python 3.
Add module initialization for Python 3.
(finish_python_initialization): Pass wchar_t * argument to
PySys_SetPath if Python 3.
* python/lib/gdb/__init__.py: Define "reload" if Python 3.
(_GdbFile): New class for common output file behavior.
(GdbOutFile): Subclass from _GdbFile.
(GdbOutputErrorFile): Ditto.
(auto_load_packages): Adjust syntax for Python 3 compatibility.
* python/lib/gdb/printing.py: Define basestr and int if Python 3.
* python/lib/gdb/prompt.py: Use sorted() function rather than
sort() method.
* python/lib/gdb/command/explore.py: Define raw_input if Python 3.
Adjust syntax for Python 3 compatibility.
* python/lib/gdb/command/pretty_printers.py: Use sorted() function
rather than sort() method.
Adjust syntax for Python 3 compatibility.
* python/lib/gdb/command/type_printers.py: Ditto.
* doc/gdb.texinfo (Inferior.read_memory): Mention that the return
value is a memoryview object if Python 3.

gdb/python/py-utils.c

@@ -54,7 +54,8 @@ make_cleanup_py_decref (PyObject *py)
 
    As an added bonus, the functions accepts a unicode string and returns it
    right away, so callers don't need to check which kind of string they've
-   got.
+   got.  In Python 3, all strings are Unicode so this case is always the 
+   one that applies.
 
    If the given object is not one of the mentioned string types, NULL is
    returned, with the TypeError python exception set.  */
@@ -70,9 +71,10 @@ python_string_to_unicode (PyObject *obj)
       unicode_str = obj;
       Py_INCREF (obj);
     }
-  
+#ifndef IS_PY3K
   else if (PyString_Check (obj))
     unicode_str = PyUnicode_FromEncodedObject (obj, host_charset (), NULL);
+#endif
   else
     {
       PyErr_SetString (PyExc_TypeError,
@@ -99,7 +101,11 @@ unicode_to_encoded_string (PyObject *unicode_str, const char *charset)
   if (string == NULL)
     return NULL;
 
+#ifdef IS_PY3K
+  result = xstrdup (PyBytes_AsString (string));
+#else
   result = xstrdup (PyString_AsString (string));
+#endif
 
   Py_DECREF (string);
 
@@ -113,14 +119,8 @@ unicode_to_encoded_string (PyObject *unicode_str, const char *charset)
 static PyObject *
 unicode_to_encoded_python_string (PyObject *unicode_str, const char *charset)
 {
-  PyObject *string;
-
   /* Translate string to named charset.  */
-  string = PyUnicode_AsEncodedString (unicode_str, charset, NULL);
-  if (string == NULL)
-    return NULL;
-
-  return string;
+  return PyUnicode_AsEncodedString (unicode_str, charset, NULL);
 }
 
 /* Returns a newly allocated string with the contents of the given unicode
@@ -167,7 +167,9 @@ python_string_to_target_string (PyObject *obj)
 
 /* Converts a python string (8-bit or unicode) to a target string in the
    target's charset.  Returns NULL on error, with a python exception
-   set.  */
+   set.
+
+   In Python 3, the returned object is a "bytes" object (not a string).  */
 PyObject *
 python_string_to_target_python_string (PyObject *obj)
 {
@@ -221,7 +223,11 @@ target_string_to_unicode (const gdb_byte *str, int length)
 int
 gdbpy_is_string (PyObject *obj)
 {
+#ifdef IS_PY3K
+  return PyUnicode_Check (obj);
+#else
   return PyString_Check (obj) || PyUnicode_Check (obj);
+#endif
 }
 
 /* Return the string representation of OBJ, i.e., str (obj).
@@ -235,7 +241,11 @@ gdbpy_obj_to_string (PyObject *obj)
 
   if (str_obj != NULL)
     {
+#ifdef IS_PY3K
+      char *msg = python_string_to_host_string (str_obj);
+#else
       char *msg = xstrdup (PyString_AsString (str_obj));
+#endif
 
       Py_DECREF (str_obj);
       return msg;
@@ -335,6 +345,11 @@ get_addr_from_python (PyObject *obj, CORE_ADDR *addr)
 PyObject *
 gdb_py_object_from_longest (LONGEST l)
 {
+#ifdef IS_PY3K
+  if (sizeof (l) > sizeof (long))
+    return PyLong_FromLongLong (l);
+  return PyLong_FromLong (l);
+#else
 #ifdef HAVE_LONG_LONG		/* Defined by Python.  */
   /* If we have 'long long', and the value overflows a 'long', use a
      Python Long; otherwise use a Python Int.  */
@@ -343,6 +358,7 @@ gdb_py_object_from_longest (LONGEST l)
     return PyLong_FromLongLong (l);
 #endif
   return PyInt_FromLong (l);
+#endif
 }
 
 /* Convert a ULONGEST to the appropriate Python object -- either an
@@ -351,6 +367,11 @@ gdb_py_object_from_longest (LONGEST l)
 PyObject *
 gdb_py_object_from_ulongest (ULONGEST l)
 {
+#ifdef IS_PY3K
+  if (sizeof (l) > sizeof (unsigned long))
+    return PyLong_FromUnsignedLongLong (l);
+  return PyLong_FromUnsignedLong (l);
+#else
 #ifdef HAVE_LONG_LONG		/* Defined by Python.  */
   /* If we have 'long long', and the value overflows a 'long', use a
      Python Long; otherwise use a Python Int.  */
@@ -362,6 +383,7 @@ gdb_py_object_from_ulongest (ULONGEST l)
     return PyLong_FromUnsignedLong (l);
 
   return PyInt_FromLong (l);
+#endif
 }
 
 /* Like PyInt_AsLong, but returns 0 on failure, 1 on success, and puts