Python/structmember.c

   1
   2 /* Map C struct members to Python object attributes */
   3
   4 #include "Python.h"
   5
   6 #include "structmember.h"
   7
   8 static PyObject *
   9 listmembers(struct memberlist *mlist)
  10 {
  11         int i, n;
  12         PyObject *v;
  13         for (n = 0; mlist[n].name != NULL; n++)
  14                 ;
  15         v = PyList_New(n);
  16         if (v != NULL) {
  17                 for (i = 0; i < n; i++)
  18                         PyList_SetItem(v, i,
  19                                        PyString_FromString(mlist[i].name));
  20                 if (PyErr_Occurred()) {
  21                         Py_DECREF(v);
  22                         v = NULL;
  23                 }
  24                 else {
  25                         PyList_Sort(v);
  26                 }
  27         }
  28         return v;
  29 }
  30
  31 PyObject *
  32 PyMember_Get(const char *addr, struct memberlist *mlist, const char *name)
  33 {
  34         struct memberlist *l;
  35
  36         if (strcmp(name, "__members__") == 0)
  37                 return listmembers(mlist);
  38         for (l = mlist; l->name != NULL; l++) {
  39                 if (strcmp(l->name, name) == 0) {
  40                         PyMemberDef copy;
  41                         copy.name = l->name;
  42                         copy.type = l->type;
  43                         copy.offset = l->offset;
  44                         copy.flags = l->flags;
  45                         copy.doc = NULL;
  46                         return PyMember_GetOne(addr, &copy);
  47                 }
  48         }
  49         PyErr_SetString(PyExc_AttributeError, name);
  50         return NULL;
  51 }
  52
  53 PyObject *
  54 PyMember_GetOne(const char *addr, PyMemberDef *l)
  55 {
  56         PyObject *v;
  57         if ((l->flags & READ_RESTRICTED) &&
  58             PyEval_GetRestricted()) {
  59                 PyErr_SetString(PyExc_RuntimeError, "restricted attribute");
  60                 return NULL;
  61         }
  62         addr += l->offset;
  63         switch (l->type) {
  64         case T_BYTE:
  65                 v = PyInt_FromLong(*(char*)addr);
  66                 break;
  67         case T_UBYTE:
  68                 v = PyLong_FromUnsignedLong(*(unsigned char*)addr);
  69                 break;
  70         case T_SHORT:
  71                 v = PyInt_FromLong(*(short*)addr);
  72                 break;
  73         case T_USHORT:
  74                 v = PyLong_FromUnsignedLong(*(unsigned short*)addr);
  75                 break;
  76         case T_INT:
  77                 v = PyInt_FromLong(*(int*)addr);
  78                 break;
  79         case T_UINT:
  80                 v = PyLong_FromUnsignedLong(*(unsigned int*)addr);
  81                 break;
  82         case T_LONG:
  83                 v = PyInt_FromLong(*(long*)addr);
  84                 break;
  85         case T_ULONG:
  86                 v = PyLong_FromUnsignedLong(*(unsigned long*)addr);
  87                 break;
  88         case T_FLOAT:
  89                 v = PyFloat_FromDouble((double)*(float*)addr);
  90                 break;
  91         case T_DOUBLE:
  92                 v = PyFloat_FromDouble(*(double*)addr);
  93                 break;
  94         case T_STRING:
  95                 if (*(char**)addr == NULL) {
  96                         Py_INCREF(Py_None);
  97                         v = Py_None;
  98                 }
  99                 else
 100                         v = PyString_FromString(*(char**)addr);
 101                 break;
 102         case T_STRING_INPLACE:
 103                 v = PyString_FromString((char*)addr);
 104                 break;
 105         case T_CHAR:
 106                 v = PyString_FromStringAndSize((char*)addr, 1);
 107                 break;
 108         case T_OBJECT:
 109                 v = *(PyObject **)addr;
 110                 if (v == NULL)
 111                         v = Py_None;
 112                 Py_INCREF(v);
 113                 break;
 114         case T_OBJECT_EX:
 115                 v = *(PyObject **)addr;
 116                 if (v == NULL)
 117                         PyErr_SetString(PyExc_AttributeError, l->name);
 118                 Py_XINCREF(v);
 119                 break;
 120 #ifdef HAVE_LONG_LONG
 121         case T_LONGLONG:
 122                 v = PyLong_FromLongLong(*(PY_LONG_LONG *)addr);
 123                 break;
 124         case T_ULONGLONG:
 125                 v = PyLong_FromUnsignedLongLong(*(unsigned PY_LONG_LONG *)addr);
 126                 break;
 127 #endif /* HAVE_LONG_LONG */
 128         default:
 129                 PyErr_SetString(PyExc_SystemError, "bad memberdescr type");
 130                 v = NULL;
 131         }
 132         return v;
 133 }
 134
 135 int
 136 PyMember_Set(char *addr, struct memberlist *mlist, const char *name, PyObject *v)
 137 {
 138         struct memberlist *l;
 139
 140         for (l = mlist; l->name != NULL; l++) {
 141                 if (strcmp(l->name, name) == 0) {
 142                         PyMemberDef copy;
 143                         copy.name = l->name;
 144                         copy.type = l->type;
 145                         copy.offset = l->offset;
 146                         copy.flags = l->flags;
 147                         copy.doc = NULL;
 148                         return PyMember_SetOne(addr, &copy, v);
 149                 }
 150         }
 151
 152         PyErr_SetString(PyExc_AttributeError, name);
 153         return -1;
 154 }
 155
 156 int
 157 PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
 158 {
 159         PyObject *oldv;
 160
 161         if ((l->flags & READONLY) || l->type == T_STRING)
 162         {
 163                 PyErr_SetString(PyExc_TypeError, "readonly attribute");
 164                 return -1;
 165         }
 166         if ((l->flags & WRITE_RESTRICTED) && PyEval_GetRestricted()) {
 167                 PyErr_SetString(PyExc_RuntimeError, "restricted attribute");
 168                 return -1;
 169         }
 170         if (v == NULL && l->type != T_OBJECT_EX && l->type != T_OBJECT) {
 171                 PyErr_SetString(PyExc_TypeError,
 172                                 "can't delete numeric/char attribute");
 173                 return -1;
 174         }
 175         addr += l->offset;
 176         switch (l->type) {
 177         case T_BYTE:{
 178                 long long_val;
 179                 long_val = PyInt_AsLong(v);
 180                 if ((long_val == -1) && PyErr_Occurred())
 181                         return -1;
 182                 /* XXX: For compatibility, only warn about truncations
 183                    for now. */
 184                 if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN))
 185                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to char");
 186                 *(char*)addr = (char)long_val;
 187                 break;
 188                 }
 189         case T_UBYTE:{
 190                 long long_val;
 191                 long_val = PyInt_AsLong(v);
 192                 if ((long_val == -1) && PyErr_Occurred())
 193                         return -1;
 194                 if ((long_val > UCHAR_MAX) || (long_val < 0))
 195                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to unsigned char");
 196                 *(unsigned char*)addr = (unsigned char)long_val;
 197                 break;
 198                 }
 199         case T_SHORT:{
 200                 long long_val;
 201                 long_val = PyInt_AsLong(v);
 202                 if ((long_val == -1) && PyErr_Occurred())
 203                         return -1;
 204                 if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN))
 205                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to short");
 206                 *(short*)addr = (short)long_val;
 207                 break;
 208                 }
 209         case T_USHORT:{
 210                 long long_val;
 211                 long_val = PyInt_AsLong(v);
 212                 if ((long_val == -1) && PyErr_Occurred())
 213                         return -1;
 214                 if ((long_val > USHRT_MAX) || (long_val < 0))
 215                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to unsigned short");
 216                 *(unsigned short*)addr = (unsigned short)long_val;
 217                 break;
 218                 }
 219         case T_INT:{
 220                 long long_val;
 221                 long_val = PyInt_AsLong(v);
 222                 if ((long_val == -1) && PyErr_Occurred())
 223                         return -1;
 224                 if ((long_val > INT_MAX) || (long_val < INT_MIN))
 225                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to int");
 226                 *(int *)addr = (int)long_val;
 227                 break;
 228                 }
 229         case T_UINT:{
 230                 unsigned long ulong_val;
 231                 ulong_val = PyLong_AsUnsignedLong(v);
 232                 if ((ulong_val == (unsigned int)-1) && PyErr_Occurred()) {
 233                         /* XXX: For compatibility, accept negative int values
 234                            as well. */
 235                         PyErr_Clear();
 236                         ulong_val = PyLong_AsLong(v);
 237                         if ((ulong_val == (unsigned int)-1) && PyErr_Occurred())
 238                                 return -1;
 239                         PyErr_Warn(PyExc_RuntimeWarning, "Writing negative value into unsigned field");
 240                 }
 241                 if (ulong_val > UINT_MAX)
 242                         PyErr_Warn(PyExc_RuntimeWarning, "Truncation of value to unsigned int");
 243                 *(unsigned int *)addr = (unsigned int)ulong_val;
 244                 break;
 245                 }
 246         case T_LONG:{
 247                 *(long*)addr = PyLong_AsLong(v);
 248                 if ((*(long*)addr == -1) && PyErr_Occurred())
 249                         return -1;
 250                 break;
 251                 }
 252         case T_ULONG:{
 253                 *(unsigned long*)addr = PyLong_AsUnsignedLong(v);
 254                 if ((*(unsigned long*)addr == (unsigned long)-1)
 255                     && PyErr_Occurred()) {
 256                         /* XXX: For compatibility, accept negative int values
 257                            as well. */
 258                         PyErr_Clear();
 259                         *(unsigned long*)addr = PyLong_AsLong(v);
 260                         if ((*(unsigned long*)addr == (unsigned int)-1) && PyErr_Occurred())
 261                                 return -1;
 262                         PyErr_Warn(PyExc_RuntimeWarning, "Writing negative value into unsigned field");
 263                 }
 264                 break;
 265                 }
 266         case T_FLOAT:{
 267                 double double_val;
 268                 double_val = PyFloat_AsDouble(v);
 269                 if ((double_val == -1) && PyErr_Occurred())
 270                         return -1;
 271                 *(float*)addr = (float)double_val;
 272                 break;
 273                 }
 274         case T_DOUBLE:
 275                 *(double*)addr = PyFloat_AsDouble(v);
 276                 if ((*(double*)addr == -1) && PyErr_Occurred())
 277                         return -1;
 278                 break;
 279         case T_OBJECT:
 280         case T_OBJECT_EX:
 281                 Py_XINCREF(v);
 282                 oldv = *(PyObject **)addr;
 283                 *(PyObject **)addr = v;
 284                 Py_XDECREF(oldv);
 285                 break;
 286         case T_CHAR:
 287                 if (PyString_Check(v) && PyString_Size(v) == 1) {
 288                         *(char*)addr = PyString_AsString(v)[0];
 289                 }
 290                 else {
 291                         PyErr_BadArgument();
 292                         return -1;
 293                 }
 294                 break;
 295 #ifdef HAVE_LONG_LONG
 296         case T_LONGLONG:
 297                 if (!PyLong_Check(v)) {
 298                         PyErr_BadArgument();
 299                         return -1;
 300                 } else {
 301                         PY_LONG_LONG value;
 302                         *(PY_LONG_LONG*)addr = value = PyLong_AsLongLong(v);
 303                         if ((value == -1) && PyErr_Occurred()) {
 304                                 return -1;
 305                         }
 306                 }
 307                 break;
 308         case T_ULONGLONG:
 309                 if (!PyLong_Check(v)) {
 310                         PyErr_BadArgument();
 311                         return -1;
 312                 } else {
 313                         unsigned PY_LONG_LONG value;
 314                         *(unsigned PY_LONG_LONG*)addr = value = PyLong_AsUnsignedLongLong(v);
 315                         if ((value == (unsigned PY_LONG_LONG)-1) &&
 316                             PyErr_Occurred()) {
 317                                 return -1;
 318                         }
 319                 }
 320                 break;
 321 #endif /* HAVE_LONG_LONG */
 322         default:
 323                 PyErr_Format(PyExc_SystemError,
 324                              "bad memberdescr type for %s", l->name);
 325                 return -1;
 326         }
 327         return 0;
 328 }