1 /* Python interface to lazy strings.
3 Copyright (C) 2010 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
21 #include "python-internal.h"
24 #include "exceptions.h"
30 /* Holds the address of the lazy string. */
33 /* Holds the encoding that will be applied to the string
34 when the string is printed by GDB. If the encoding is set
35 to None then GDB will select the most appropriate
36 encoding when the sting is printed. */
39 /* Holds the length of the string in characters. If the
40 length is -1, then the string will be fetched and encoded up to
41 the first null of appropriate width. */
44 /* This attribute holds the type that is represented by the lazy
49 static PyTypeObject lazy_string_object_type;
52 stpy_get_address (PyObject *self, void *closure)
54 lazy_string_object *self_string = (lazy_string_object *) self;
55 return PyLong_FromUnsignedLongLong (self_string->address);
59 stpy_get_encoding (PyObject *self, void *closure)
61 lazy_string_object *self_string = (lazy_string_object *) self;
64 /* An encoding can be set to NULL by the user, so check before
65 attempting a Python FromString call. If NULL return Py_None. */
66 if (self_string->encoding)
67 result = PyString_FromString (self_string->encoding);
78 stpy_get_length (PyObject *self, void *closure)
80 lazy_string_object *self_string = (lazy_string_object *) self;
81 return PyLong_FromLong (self_string->length);
85 stpy_get_type (PyObject *self, void *closure)
87 lazy_string_object *str_obj = (lazy_string_object *) self;
88 return type_to_type_object (str_obj->type);
92 stpy_convert_to_value (PyObject *self, PyObject *args)
94 lazy_string_object *self_string = (lazy_string_object *) self;
97 val = value_at_lazy (self_string->type, self_string->address);
98 return value_to_value_object (val);
102 stpy_dealloc (PyObject *self)
104 lazy_string_object *self_string = (lazy_string_object *) self;
105 xfree (self_string->encoding);
109 gdbpy_create_lazy_string_object (CORE_ADDR address, long length,
110 const char *encoding, struct type *type)
112 lazy_string_object *str_obj = NULL;
116 PyErr_SetString (PyExc_MemoryError,
117 "Cannot create a lazy string from a GDB-side string.");
123 PyErr_SetString (PyExc_RuntimeError,
124 "A lazy string's type cannot be NULL.");
128 str_obj = PyObject_New (lazy_string_object, &lazy_string_object_type);
132 str_obj->address = address;
133 str_obj->length = length;
134 if (encoding == NULL || !strcmp (encoding, ""))
135 str_obj->encoding = NULL;
137 str_obj->encoding = xstrdup (encoding);
138 str_obj->type = type;
140 return (PyObject *) str_obj;
144 gdbpy_initialize_lazy_string (void)
146 if (PyType_Ready (&lazy_string_object_type) < 0)
149 Py_INCREF (&lazy_string_object_type);
152 /* Determine whether the printer object pointed to by OBJ is a
153 Python lazy string. */
155 gdbpy_is_lazy_string (PyObject *result)
157 return PyObject_TypeCheck (result, &lazy_string_object_type);
160 /* Extract and return the actual string from the lazy string object
161 STRING. Addtionally, the string type is written to *STR_TYPE, the
162 string length is written to *LENGTH, and the string encoding is
163 written to *ENCODING. On error, NULL is returned. The caller is
164 responsible for freeing the returned buffer. */
166 gdbpy_extract_lazy_string (PyObject *string, struct type **str_type,
167 long *length, char **encoding)
171 gdb_byte *buffer = NULL;
174 struct gdbarch *gdbarch;
175 enum bfd_endian byte_order;
176 PyObject *py_len = NULL, *py_encoding = NULL;
177 PyObject *py_addr = NULL, *py_type = NULL;
178 volatile struct gdb_exception except;
180 py_len = PyObject_GetAttrString (string, "length");
181 py_encoding = PyObject_GetAttrString (string, "encoding");
182 py_addr = PyObject_GetAttrString (string, "address");
183 py_type = PyObject_GetAttrString (string, "type");
185 /* A NULL encoding, length, address or type is not ok. */
186 if (!py_len || !py_encoding || !py_addr || !py_type)
189 *length = PyLong_AsLong (py_len);
190 addr = PyLong_AsUnsignedLongLong (py_addr);
192 /* If the user supplies Py_None an encoding, set encoding to NULL.
193 This will trigger the resulting LA_PRINT_CALL to automatically
194 select an encoding. */
195 if (py_encoding == Py_None)
198 *encoding = xstrdup (PyString_AsString (py_encoding));
200 *str_type = type_object_to_type (py_type);
201 gdbarch = get_type_arch (*str_type);
202 byte_order = gdbarch_byte_order (gdbarch);
203 width = TYPE_LENGTH (*str_type);
205 TRY_CATCH (except, RETURN_MASK_ALL)
207 errcode = read_string (addr, *length, width,
208 *length, byte_order, &buffer,
211 if (except.reason < 0)
213 PyErr_Format (except.reason == RETURN_QUIT \
214 ? PyExc_KeyboardInterrupt : PyExc_RuntimeError, \
215 "%s", except.message); \
223 *length = bytes_read / width;
225 Py_DECREF (py_encoding);
232 Py_XDECREF (py_encoding);
234 Py_XDECREF (py_addr);
235 Py_XDECREF (py_type);
244 static PyMethodDef lazy_string_object_methods[] = {
245 { "value", stpy_convert_to_value, METH_NOARGS,
246 "Create a (lazy) value that contains a pointer to the string." },
247 {NULL} /* Sentinel */
251 static PyGetSetDef lazy_string_object_getset[] = {
252 { "address", stpy_get_address, NULL, "Address of the string.", NULL },
253 { "encoding", stpy_get_encoding, NULL, "Encoding of the string.", NULL },
254 { "length", stpy_get_length, NULL, "Length of the string.", NULL },
255 { "type", stpy_get_type, NULL, "Type associated with the string.", NULL },
256 { NULL } /* Sentinel */
259 static PyTypeObject lazy_string_object_type = {
260 PyObject_HEAD_INIT (NULL)
262 "gdb.LazyString", /*tp_name*/
263 sizeof (lazy_string_object), /*tp_basicsize*/
265 stpy_dealloc, /*tp_dealloc*/
272 0, /*tp_as_sequence*/
280 Py_TPFLAGS_DEFAULT, /*tp_flags*/
281 "GDB lazy string object", /* tp_doc */
284 0, /* tp_richcompare */
285 0, /* tp_weaklistoffset */
288 lazy_string_object_methods, /* tp_methods */
290 lazy_string_object_getset /* tp_getset */