gdb/python/py-function.c

   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 \f
  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<>
  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 *
  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
 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
 137 gdbpy_initialize_functions (void)
 138 {
 139   fnpy_object_type.tp_new = PyType_GenericNew;
 140   return gdbpy_type_ready (&fnpy_object_type);
 141 }
 142
 143 GDBPY_INITIALIZE_FILE (gdbpy_initialize_functions);
 144
 145 \f
 146
 147 PyTypeObject fnpy_object_type =
 148 {
 149   PyVarObject_HEAD_INIT (NULL, 0)
 150   "gdb.Function",                 /*tp_name*/
 151   sizeof (PyObject),              /*tp_basicsize*/
 152   0,                              /*tp_itemsize*/
 153   0,                              /*tp_dealloc*/
 154   0,                              /*tp_print*/
 155   0,                              /*tp_getattr*/
 156   0,                              /*tp_setattr*/
 157   0,                              /*tp_compare*/
 158   0,                              /*tp_repr*/
 159   0,                              /*tp_as_number*/
 160   0,                              /*tp_as_sequence*/
 161   0,                              /*tp_as_mapping*/
 162   0,                              /*tp_hash */
 163   0,                              /*tp_call*/
 164   0,                              /*tp_str*/
 165   0,                              /*tp_getattro*/
 166   0,                              /*tp_setattro*/
 167   0,                              /*tp_as_buffer*/
 168   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
 169   "GDB function object",          /* tp_doc */
 170   0,                              /* tp_traverse */
 171   0,                              /* tp_clear */
 172   0,                              /* tp_richcompare */
 173   0,                              /* tp_weaklistoffset */
 174   0,                              /* tp_iter */
 175   0,                              /* tp_iternext */
 176   0,                              /* tp_methods */
 177   0,                              /* tp_members */
 178   0,                              /* tp_getset */
 179   0,                              /* tp_base */
 180   0,                              /* tp_dict */
 181   0,                              /* tp_descr_get */
 182   0,                              /* tp_descr_set */
 183   0,                              /* tp_dictoffset */
 184   fnpy_init,                      /* tp_init */
 185   0,                              /* tp_alloc */
 186 };