1/* Convenience functions implemented in Python.
2
3   Copyright (C) 2008-2020 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20
21#include "defs.h"
22#include "value.h"
23#include "python-internal.h"
24#include "charset.h"
25#include "gdbcmd.h"
26#include "cli/cli-decode.h"
27#include "completer.h"
28#include "expression.h"
29#include "language.h"
30
31extern PyTypeObject fnpy_object_type
32    CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("PyObject");
33
34
35
36/* Return a reference to a tuple ARGC elements long.  Each element of the
37   tuple is a PyObject converted from the corresponding element of ARGV.  */
38
39static gdbpy_ref<>
40convert_values_to_python (int argc, struct value **argv)
41{
42  int i;
43  gdbpy_ref<> result (PyTuple_New (argc));
44
45  if (result == NULL)
46    return NULL;
47
48  for (i = 0; i < argc; ++i)
49    {
50      gdbpy_ref<> elt (value_to_value_object (argv[i]));
51      if (elt == NULL)
52	return NULL;
53      PyTuple_SetItem (result.get (), i, elt.release ());
54    }
55  return result;
56}
57
58/* Call a Python function object's invoke method.  */
59
60static struct value *
61fnpy_call (struct gdbarch *gdbarch, const struct language_defn *language,
62	   void *cookie, int argc, struct value **argv)
63{
64  /* The gdbpy_enter object needs to be placed first, so that it's the last to
65     be destroyed.  */
66  gdbpy_enter enter_py (gdbarch, language);
67  struct value *value;
68  gdbpy_ref<> result;
69  gdbpy_ref<> args = convert_values_to_python (argc, argv);
70
71  /* convert_values_to_python can return NULL on error.  If we
72     encounter this, do not call the function, but allow the Python ->
73     error code conversion below to deal with the Python exception.
74     Note, that this is different if the function simply does not
75     have arguments.  */
76
77  if (args != NULL)
78    {
79      gdbpy_ref<> callable (PyObject_GetAttrString ((PyObject *) cookie,
80						    "invoke"));
81      if (callable == NULL)
82	error (_("No method named 'invoke' in object."));
83
84      result.reset (PyObject_Call (callable.get (), args.get (), NULL));
85    }
86
87  if (result == NULL)
88    gdbpy_handle_exception ();
89
90  value = convert_value_from_python (result.get ());
91  if (value == NULL)
92    {
93      gdbpy_print_stack ();
94      error (_("Error while executing Python code."));
95    }
96
97  return value;
98}
99
100/* Initializer for a Function object.  It takes one argument, the name
101   of the function.  */
102
103static int
104fnpy_init (PyObject *self, PyObject *args, PyObject *kwds)
105{
106  const char *name;
107  gdb::unique_xmalloc_ptr<char> docstring;
108
109  if (! PyArg_ParseTuple (args, "s", &name))
110    return -1;
111
112  gdbpy_ref<> self_ref = gdbpy_ref<>::new_reference (self);
113
114  if (PyObject_HasAttrString (self, "__doc__"))
115    {
116      gdbpy_ref<> ds_obj (PyObject_GetAttrString (self, "__doc__"));
117      if (ds_obj != NULL)
118	{
119	  if (gdbpy_is_string (ds_obj.get ()))
120	    {
121	      docstring = python_string_to_host_string (ds_obj.get ());
122	      if (docstring == NULL)
123		return -1;
124	    }
125	}
126    }
127  if (! docstring)
128    docstring.reset (xstrdup (_("This function is not documented.")));
129
130  add_internal_function (make_unique_xstrdup (name), std::move (docstring),
131			 fnpy_call, self_ref.release ());
132  return 0;
133}
134
135/* Initialize internal function support.  */
136
137int
138gdbpy_initialize_functions (void)
139{
140  fnpy_object_type.tp_new = PyType_GenericNew;
141  if (PyType_Ready (&fnpy_object_type) < 0)
142    return -1;
143
144  return gdb_pymodule_addobject (gdb_module, "Function",
145				 (PyObject *) &fnpy_object_type);
146}
147
148
149
150PyTypeObject fnpy_object_type =
151{
152  PyVarObject_HEAD_INIT (NULL, 0)
153  "gdb.Function",		  /*tp_name*/
154  sizeof (PyObject),		  /*tp_basicsize*/
155  0,				  /*tp_itemsize*/
156  0,				  /*tp_dealloc*/
157  0,				  /*tp_print*/
158  0,				  /*tp_getattr*/
159  0,				  /*tp_setattr*/
160  0,				  /*tp_compare*/
161  0,				  /*tp_repr*/
162  0,				  /*tp_as_number*/
163  0,				  /*tp_as_sequence*/
164  0,				  /*tp_as_mapping*/
165  0,				  /*tp_hash */
166  0,				  /*tp_call*/
167  0,				  /*tp_str*/
168  0,				  /*tp_getattro*/
169  0,				  /*tp_setattro*/
170  0,				  /*tp_as_buffer*/
171  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
172  "GDB function object",	  /* tp_doc */
173  0,				  /* tp_traverse */
174  0,				  /* tp_clear */
175  0,				  /* tp_richcompare */
176  0,				  /* tp_weaklistoffset */
177  0,				  /* tp_iter */
178  0,				  /* tp_iternext */
179  0,				  /* tp_methods */
180  0,				  /* tp_members */
181  0,				  /* tp_getset */
182  0,				  /* tp_base */
183  0,				  /* tp_dict */
184  0,				  /* tp_descr_get */
185  0,				  /* tp_descr_set */
186  0,				  /* tp_dictoffset */
187  fnpy_init,			  /* tp_init */
188  0,				  /* tp_alloc */
189};
190