1 /* Convenience functions implemented in Python.
2 
3    Copyright (C) 2008-2024 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 "value.h"
22 #include "python-internal.h"
23 #include "charset.h"
24 #include "cli/cli-cmds.h"
25 #include "cli/cli-decode.h"
26 #include "completer.h"
27 #include "expression.h"
28 #include "language.h"
29 
30 extern PyTypeObject fnpy_object_type
31     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("PyObject");
32 
33 
34 
35 /* Return a reference to a tuple ARGC elements long.  Each element of the
36    tuple is a PyObject converted from the corresponding element of ARGV.  */
37 
38 static gdbpy_ref<>
convert_values_to_python(int argc,struct value ** argv)39 convert_values_to_python (int argc, struct value **argv)
40 {
41   int i;
42   gdbpy_ref<> result (PyTuple_New (argc));
43 
44   if (result == NULL)
45     return NULL;
46 
47   for (i = 0; i < argc; ++i)
48     {
49       gdbpy_ref<> elt (value_to_value_object (argv[i]));
50       if (elt == NULL)
51           return NULL;
52       PyTuple_SetItem (result.get (), i, elt.release ());
53     }
54   return result;
55 }
56 
57 /* Call a Python function object's invoke method.  */
58 
59 static struct value *
fnpy_call(struct gdbarch * gdbarch,const struct language_defn * language,void * cookie,int argc,struct value ** argv)60 fnpy_call (struct gdbarch *gdbarch, const struct language_defn *language,
61              void *cookie, int argc, struct value **argv)
62 {
63   /* The gdbpy_enter object needs to be placed first, so that it's the last to
64      be destroyed.  */
65   gdbpy_enter enter_py (gdbarch, language);
66   struct value *value;
67   gdbpy_ref<> result;
68   gdbpy_ref<> args = convert_values_to_python (argc, argv);
69 
70   /* convert_values_to_python can return NULL on error.  If we
71      encounter this, do not call the function, but allow the Python ->
72      error code conversion below to deal with the Python exception.
73      Note, that this is different if the function simply does not
74      have arguments.  */
75 
76   if (args != NULL)
77     {
78       gdbpy_ref<> callable (PyObject_GetAttrString ((PyObject *) cookie,
79                                                                 "invoke"));
80       if (callable == NULL)
81           error (_("No method named 'invoke' in object."));
82 
83       result.reset (PyObject_Call (callable.get (), args.get (), NULL));
84     }
85 
86   if (result == NULL)
87     gdbpy_handle_exception ();
88 
89   value = convert_value_from_python (result.get ());
90   if (value == NULL)
91     {
92       gdbpy_print_stack ();
93       error (_("Error while executing Python code."));
94     }
95 
96   return value;
97 }
98 
99 /* Initializer for a Function object.  It takes one argument, the name
100    of the function.  */
101 
102 static int
fnpy_init(PyObject * self,PyObject * args,PyObject * kwds)103 fnpy_init (PyObject *self, PyObject *args, PyObject *kwds)
104 {
105   const char *name;
106   gdb::unique_xmalloc_ptr<char> docstring;
107 
108   if (! PyArg_ParseTuple (args, "s", &name))
109     return -1;
110 
111   gdbpy_ref<> self_ref = gdbpy_ref<>::new_reference (self);
112 
113   if (PyObject_HasAttrString (self, "__doc__"))
114     {
115       gdbpy_ref<> ds_obj (PyObject_GetAttrString (self, "__doc__"));
116       if (ds_obj != NULL)
117           {
118             if (gdbpy_is_string (ds_obj.get ()))
119               {
120                 docstring = python_string_to_host_string (ds_obj.get ());
121                 if (docstring == NULL)
122                     return -1;
123               }
124           }
125     }
126   if (! docstring)
127     docstring.reset (xstrdup (_("This function is not documented.")));
128 
129   add_internal_function (make_unique_xstrdup (name), std::move (docstring),
130                                fnpy_call, self_ref.release ());
131   return 0;
132 }
133 
134 /* Initialize internal function support.  */
135 
136 static int CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION
gdbpy_initialize_functions(void)137 gdbpy_initialize_functions (void)
138 {
139   fnpy_object_type.tp_new = PyType_GenericNew;
140   if (PyType_Ready (&fnpy_object_type) < 0)
141     return -1;
142 
143   return gdb_pymodule_addobject (gdb_module, "Function",
144                                          (PyObject *) &fnpy_object_type);
145 }
146 
147 GDBPY_INITIALIZE_FILE (gdbpy_initialize_functions);
148 
149 
150 
151 PyTypeObject fnpy_object_type =
152 {
153   PyVarObject_HEAD_INIT (NULL, 0)
154   "gdb.Function",               /*tp_name*/
155   sizeof (PyObject),                      /*tp_basicsize*/
156   0,                                      /*tp_itemsize*/
157   0,                                      /*tp_dealloc*/
158   0,                                      /*tp_print*/
159   0,                                      /*tp_getattr*/
160   0,                                      /*tp_setattr*/
161   0,                                      /*tp_compare*/
162   0,                                      /*tp_repr*/
163   0,                                      /*tp_as_number*/
164   0,                                      /*tp_as_sequence*/
165   0,                                      /*tp_as_mapping*/
166   0,                                      /*tp_hash */
167   0,                                      /*tp_call*/
168   0,                                      /*tp_str*/
169   0,                                      /*tp_getattro*/
170   0,                                      /*tp_setattro*/
171   0,                                      /*tp_as_buffer*/
172   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
173   "GDB function object",        /* tp_doc */
174   0,                                      /* tp_traverse */
175   0,                                      /* tp_clear */
176   0,                                      /* tp_richcompare */
177   0,                                      /* tp_weaklistoffset */
178   0,                                      /* tp_iter */
179   0,                                      /* tp_iternext */
180   0,                                      /* tp_methods */
181   0,                                      /* tp_members */
182   0,                                      /* tp_getset */
183   0,                                      /* tp_base */
184   0,                                      /* tp_dict */
185   0,                                      /* tp_descr_get */
186   0,                                      /* tp_descr_set */
187   0,                                      /* tp_dictoffset */
188   fnpy_init,                              /* tp_init */
189   0,                                      /* tp_alloc */
190 };
191