1 /* Convenience functions implemented in Python. 2 3 Copyright (C) 2008-2014 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 "exceptions.h" 24 #include "python-internal.h" 25 #include "charset.h" 26 #include "gdbcmd.h" 27 #include "cli/cli-decode.h" 28 #include "completer.h" 29 #include "expression.h" 30 #include "language.h" 31 32 static PyTypeObject fnpy_object_type 33 CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("PyObject"); 34 35 36 37 static PyObject * 38 convert_values_to_python (int argc, struct value **argv) 39 { 40 int i; 41 PyObject *result = PyTuple_New (argc); 42 43 if (! result) 44 return NULL; 45 46 for (i = 0; i < argc; ++i) 47 { 48 PyObject *elt = value_to_value_object (argv[i]); 49 if (! elt) 50 { 51 Py_DECREF (result); 52 return NULL; 53 } 54 PyTuple_SetItem (result, i, elt); 55 } 56 return result; 57 } 58 59 /* Call a Python function object's invoke method. */ 60 61 static struct value * 62 fnpy_call (struct gdbarch *gdbarch, const struct language_defn *language, 63 void *cookie, int argc, struct value **argv) 64 { 65 struct value *value = NULL; 66 /* 'result' must be set to NULL, this initially indicates whether 67 the function was called, or not. */ 68 PyObject *result = NULL; 69 PyObject *callable, *args; 70 struct cleanup *cleanup; 71 72 cleanup = ensure_python_env (gdbarch, language); 73 74 args = convert_values_to_python (argc, argv); 75 /* convert_values_to_python can return NULL on error. If we 76 encounter this, do not call the function, but allow the Python -> 77 error code conversion below to deal with the Python exception. 78 Note, that this is different if the function simply does not 79 have arguments. */ 80 81 if (args) 82 { 83 callable = PyObject_GetAttrString ((PyObject *) cookie, "invoke"); 84 if (! callable) 85 { 86 Py_DECREF (args); 87 error (_("No method named 'invoke' in object.")); 88 } 89 90 result = PyObject_Call (callable, args, NULL); 91 Py_DECREF (callable); 92 Py_DECREF (args); 93 } 94 95 if (!result) 96 { 97 PyObject *ptype, *pvalue, *ptraceback; 98 char *msg; 99 100 PyErr_Fetch (&ptype, &pvalue, &ptraceback); 101 102 /* Try to fetch an error message contained within ptype, pvalue. 103 When fetching the error message we need to make our own copy, 104 we no longer own ptype, pvalue after the call to PyErr_Restore. */ 105 106 msg = gdbpy_exception_to_string (ptype, pvalue); 107 make_cleanup (xfree, msg); 108 109 if (msg == NULL) 110 { 111 /* An error occurred computing the string representation of the 112 error message. This is rare, but we should inform the user. */ 113 114 printf_filtered (_("An error occurred in a Python " 115 "convenience function\n" 116 "and then another occurred computing the " 117 "error message.\n")); 118 gdbpy_print_stack (); 119 } 120 121 /* Don't print the stack for gdb.GdbError exceptions. 122 It is generally used to flag user errors. 123 124 We also don't want to print "Error occurred in Python command" 125 for user errors. However, a missing message for gdb.GdbError 126 exceptions is arguably a bug, so we flag it as such. */ 127 128 if (!PyErr_GivenExceptionMatches (ptype, gdbpy_gdberror_exc) 129 || msg == NULL || *msg == '\0') 130 { 131 PyErr_Restore (ptype, pvalue, ptraceback); 132 gdbpy_print_stack (); 133 if (msg != NULL && *msg != '\0') 134 error (_("Error occurred in Python convenience function: %s"), 135 msg); 136 else 137 error (_("Error occurred in Python convenience function.")); 138 } 139 else 140 { 141 Py_XDECREF (ptype); 142 Py_XDECREF (pvalue); 143 Py_XDECREF (ptraceback); 144 error ("%s", msg); 145 } 146 } 147 148 value = convert_value_from_python (result); 149 if (value == NULL) 150 { 151 Py_DECREF (result); 152 gdbpy_print_stack (); 153 error (_("Error while executing Python code.")); 154 } 155 156 Py_DECREF (result); 157 do_cleanups (cleanup); 158 159 return value; 160 } 161 162 /* Initializer for a Function object. It takes one argument, the name 163 of the function. */ 164 165 static int 166 fnpy_init (PyObject *self, PyObject *args, PyObject *kwds) 167 { 168 const char *name; 169 char *docstring = NULL; 170 171 if (! PyArg_ParseTuple (args, "s", &name)) 172 return -1; 173 Py_INCREF (self); 174 175 if (PyObject_HasAttrString (self, "__doc__")) 176 { 177 PyObject *ds_obj = PyObject_GetAttrString (self, "__doc__"); 178 if (ds_obj != NULL) 179 { 180 if (gdbpy_is_string (ds_obj)) 181 { 182 docstring = python_string_to_host_string (ds_obj); 183 if (docstring == NULL) 184 { 185 Py_DECREF (self); 186 Py_DECREF (ds_obj); 187 return -1; 188 } 189 } 190 191 Py_DECREF (ds_obj); 192 } 193 } 194 if (! docstring) 195 docstring = xstrdup (_("This function is not documented.")); 196 197 add_internal_function (name, docstring, fnpy_call, self); 198 return 0; 199 } 200 201 /* Initialize internal function support. */ 202 203 int 204 gdbpy_initialize_functions (void) 205 { 206 fnpy_object_type.tp_new = PyType_GenericNew; 207 if (PyType_Ready (&fnpy_object_type) < 0) 208 return -1; 209 210 return gdb_pymodule_addobject (gdb_module, "Function", 211 (PyObject *) &fnpy_object_type); 212 } 213 214 215 216 static PyTypeObject fnpy_object_type = 217 { 218 PyVarObject_HEAD_INIT (NULL, 0) 219 "gdb.Function", /*tp_name*/ 220 sizeof (PyObject), /*tp_basicsize*/ 221 0, /*tp_itemsize*/ 222 0, /*tp_dealloc*/ 223 0, /*tp_print*/ 224 0, /*tp_getattr*/ 225 0, /*tp_setattr*/ 226 0, /*tp_compare*/ 227 0, /*tp_repr*/ 228 0, /*tp_as_number*/ 229 0, /*tp_as_sequence*/ 230 0, /*tp_as_mapping*/ 231 0, /*tp_hash */ 232 0, /*tp_call*/ 233 0, /*tp_str*/ 234 0, /*tp_getattro*/ 235 0, /*tp_setattro*/ 236 0, /*tp_as_buffer*/ 237 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ 238 "GDB function object", /* tp_doc */ 239 0, /* tp_traverse */ 240 0, /* tp_clear */ 241 0, /* tp_richcompare */ 242 0, /* tp_weaklistoffset */ 243 0, /* tp_iter */ 244 0, /* tp_iternext */ 245 0, /* tp_methods */ 246 0, /* tp_members */ 247 0, /* tp_getset */ 248 0, /* tp_base */ 249 0, /* tp_dict */ 250 0, /* tp_descr_get */ 251 0, /* tp_descr_set */ 252 0, /* tp_dictoffset */ 253 fnpy_init, /* tp_init */ 254 0, /* tp_alloc */ 255 }; 256