gdb/python/python-utils.c

   1 /* General utility routines for GDB/Python.
   2
   3    Copyright (C) 2008 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 #include "defs.h"
  21 #include "charset.h"
  22 #include "python-internal.h"
  23
  24
  25 /* This is a cleanup function which decrements the refcount on a
  26    Python object.  */
  27
  28 static void
  29 py_decref (void *p)
  30 {
  31   PyObject *py = p;
  32   /* Note that we need the extra braces in this 'if' to avoid a
  33      warning from gcc.  */
  34   if (py)
  35     {
  36       Py_DECREF (py);
  37     }
  38 }
  39
  40 /* Return a new cleanup which will decrement the Python object's
  41    refcount when run.  */
  42
  43 struct cleanup *
  44 make_cleanup_py_decref (PyObject *py)
  45 {
  46   return make_cleanup (py_decref, (void *) py);
  47 }
  48
  49 /* A cleanup function to restore the thread state.  */
  50
  51 static void
  52 py_gil_restore (void *p)
  53 {
  54   PyGILState_STATE *state = p;
  55   PyGILState_Release (*state);
  56 }
  57
  58 /* Return a new cleanup which will restore the Python GIL state.  */
  59
  60 struct cleanup *
  61 make_cleanup_py_restore_gil (PyGILState_STATE *state)
  62 {
  63   return make_cleanup (py_gil_restore, state);
  64 }
  65
  66 /* Converts a Python 8-bit string to a unicode string object.  Assumes the
  67    8-bit string is in the host charset.  If an error occurs during conversion,
  68    returns NULL with a python exception set.
  69
  70    As an added bonus, the functions accepts a unicode string and returns it
  71    right away, so callers don't need to check which kind of string they've
  72    got.
  73
  74    If the given object is not one of the mentioned string types, NULL is
  75    returned, with the TypeError python exception set.  */
  76 PyObject *
  77 python_string_to_unicode (PyObject *obj)
  78 {
  79   PyObject *unicode_str;
  80
  81   /* If obj is already a unicode string, just return it.
  82      I wish life was always that simple...  */
  83   if (PyUnicode_Check (obj))
  84     unicode_str = obj;
  85   else if (PyString_Check (obj))
  86     unicode_str = PyUnicode_FromEncodedObject (obj, host_charset (), NULL);
  87   else
  88     {
  89       PyErr_SetString (PyExc_TypeError,
  90                        _("Expected a string or unicode object."));
  91       unicode_str = NULL;
  92     }
  93
  94   return unicode_str;
  95 }
  96
  97 /* Returns a newly allocated string with the contents of the given unicode
  98    string object converted to the target's charset.  If an error occurs during
  99    the conversion, NULL will be returned and a python exception will be set.
 100
 101    The caller is responsible for xfree'ing the string.  */
 102 char *
 103 unicode_to_target_string (PyObject *unicode_str)
 104 {
 105   char *target_string;
 106   PyObject *string;
 107
 108   /* Translate string to target's charset.  */
 109   string = PyUnicode_AsEncodedString (unicode_str, target_charset (), NULL);
 110   if (string == NULL)
 111     return NULL;
 112
 113   target_string = xstrdup (PyString_AsString (string));
 114
 115   Py_DECREF (string);
 116
 117   return target_string;
 118 }
 119
 120 /* Converts a python string (8-bit or unicode) to a target string in
 121    the target's charset.  Returns NULL on error, with a python exception set.
 122
 123    The caller is responsible for xfree'ing the string.  */
 124 char *
 125 python_string_to_target_string (PyObject *obj)
 126 {
 127   PyObject *str;
 128
 129   str = python_string_to_unicode (obj);
 130   if (str == NULL)
 131     return NULL;
 132
 133   return unicode_to_target_string (str);
 134 }