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 PyObject *
   9 PyMember_GetOne(const char *addr, PyMemberDef *l)
  10 {
  11         PyObject *v;
  12
  13         addr += l->offset;
  14         switch (l->type) {
  15         case T_BOOL:
  16                 v = PyBool_FromLong(*(char*)addr);
  17                 break;
  18         case T_BYTE:
  19                 v = PyLong_FromLong(*(char*)addr);
  20                 break;
  21         case T_UBYTE:
  22                 v = PyLong_FromUnsignedLong(*(unsigned char*)addr);
  23                 break;
  24         case T_SHORT:
  25                 v = PyLong_FromLong(*(short*)addr);
  26                 break;
  27         case T_USHORT:
  28                 v = PyLong_FromUnsignedLong(*(unsigned short*)addr);
  29                 break;
  30         case T_INT:
  31                 v = PyLong_FromLong(*(int*)addr);
  32                 break;
  33         case T_UINT:
  34                 v = PyLong_FromUnsignedLong(*(unsigned int*)addr);
  35                 break;
  36         case T_LONG:
  37                 v = PyLong_FromLong(*(long*)addr);
  38                 break;
  39         case T_ULONG:
  40                 v = PyLong_FromUnsignedLong(*(unsigned long*)addr);
  41                 break;
  42         case T_PYSSIZET:
  43                 v = PyLong_FromSsize_t(*(Py_ssize_t*)addr);
  44                 break;
  45         case T_FLOAT:
  46                 v = PyFloat_FromDouble((double)*(float*)addr);
  47                 break;
  48         case T_DOUBLE:
  49                 v = PyFloat_FromDouble(*(double*)addr);
  50                 break;
  51         case T_STRING:
  52                 if (*(char**)addr == NULL) {
  53                         Py_INCREF(Py_None);
  54                         v = Py_None;
  55                 }
  56                 else
  57                         v = PyUnicode_FromString(*(char**)addr);
  58                 break;
  59         case T_STRING_INPLACE:
  60                 v = PyUnicode_FromString((char*)addr);
  61                 break;
  62         case T_CHAR:
  63                 v = PyUnicode_FromStringAndSize((char*)addr, 1);
  64                 break;
  65         case T_OBJECT:
  66                 v = *(PyObject **)addr;
  67                 if (v == NULL)
  68                         v = Py_None;
  69                 Py_INCREF(v);
  70                 break;
  71         case T_OBJECT_EX:
  72                 v = *(PyObject **)addr;
  73                 if (v == NULL)
  74                         PyErr_SetString(PyExc_AttributeError, l->name);
  75                 Py_XINCREF(v);
  76                 break;
  77 #ifdef HAVE_LONG_LONG
  78         case T_LONGLONG:
  79                 v = PyLong_FromLongLong(*(PY_LONG_LONG *)addr);
  80                 break;
  81         case T_ULONGLONG:
  82                 v = PyLong_FromUnsignedLongLong(*(unsigned PY_LONG_LONG *)addr);
  83                 break;
  84 #endif /* HAVE_LONG_LONG */
  85         case T_NONE:
  86                 v = Py_None;
  87                 Py_INCREF(v);
  88                 break;
  89         default:
  90                 PyErr_SetString(PyExc_SystemError, "bad memberdescr type");
  91                 v = NULL;
  92         }
  93         return v;
  94 }
  95
  96 #define WARN(msg)                                               \
  97     do {                                                        \
  98         if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0)     \
  99                 return -1;                                      \
 100     } while (0)
 101
 102 int
 103 PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
 104 {
 105         PyObject *oldv;
 106
 107         if ((l->flags & READONLY) || l->type == T_STRING)
 108         {
 109                 PyErr_SetString(PyExc_AttributeError, "readonly attribute");
 110                 return -1;
 111         }
 112         if (v == NULL && l->type != T_OBJECT_EX && l->type != T_OBJECT) {
 113                 PyErr_SetString(PyExc_TypeError,
 114                                 "can't delete numeric/char attribute");
 115                 return -1;
 116         }
 117         addr += l->offset;
 118         switch (l->type) {
 119         case T_BOOL:{
 120                 if (!PyBool_Check(v)) {
 121                         PyErr_SetString(PyExc_TypeError,
 122                                         "attribute value type must be bool");
 123                         return -1;
 124                 }
 125                 if (v == Py_True)
 126                         *(char*)addr = (char) 1;
 127                 else
 128                         *(char*)addr = (char) 0;
 129                 break;
 130                 }
 131         case T_BYTE:{
 132                 long long_val = PyLong_AsLong(v);
 133                 if ((long_val == -1) && PyErr_Occurred())
 134                         return -1;
 135                 *(char*)addr = (char)long_val;
 136                 /* XXX: For compatibility, only warn about truncations
 137                    for now. */
 138                 if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN))
 139                         WARN("Truncation of value to char");
 140                 break;
 141                 }
 142         case T_UBYTE:{
 143                 long long_val = PyLong_AsLong(v);
 144                 if ((long_val == -1) && PyErr_Occurred())
 145                         return -1;
 146                 *(unsigned char*)addr = (unsigned char)long_val;
 147                 if ((long_val > UCHAR_MAX) || (long_val < 0))
 148                         WARN("Truncation of value to unsigned char");
 149                 break;
 150                 }
 151         case T_SHORT:{
 152                 long long_val = PyLong_AsLong(v);
 153                 if ((long_val == -1) && PyErr_Occurred())
 154                         return -1;
 155                 *(short*)addr = (short)long_val;
 156                 if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN))
 157                         WARN("Truncation of value to short");
 158                 break;
 159                 }
 160         case T_USHORT:{
 161                 long long_val = PyLong_AsLong(v);
 162                 if ((long_val == -1) && PyErr_Occurred())
 163                         return -1;
 164                 *(unsigned short*)addr = (unsigned short)long_val;
 165                 if ((long_val > USHRT_MAX) || (long_val < 0))
 166                         WARN("Truncation of value to unsigned short");
 167                 break;
 168                 }
 169         case T_INT:{
 170                 long long_val = PyLong_AsLong(v);
 171                 if ((long_val == -1) && PyErr_Occurred())
 172                         return -1;
 173                 *(int *)addr = (int)long_val;
 174                 if ((long_val > INT_MAX) || (long_val < INT_MIN))
 175                         WARN("Truncation of value to int");
 176                 break;
 177                 }
 178         case T_UINT:{
 179                 unsigned long ulong_val = PyLong_AsUnsignedLong(v);
 180                 if ((ulong_val == (unsigned int)-1) && PyErr_Occurred()) {
 181                         /* XXX: For compatibility, accept negative int values
 182                            as well. */
 183                         PyErr_Clear();
 184                         ulong_val = PyLong_AsLong(v);
 185                         if ((ulong_val == (unsigned int)-1) && PyErr_Occurred())
 186                                 return -1;
 187                         *(unsigned int *)addr = (unsigned int)ulong_val;
 188                         WARN("Writing negative value into unsigned field");
 189                 } else
 190                         *(unsigned int *)addr = (unsigned int)ulong_val;
 191                 if (ulong_val > UINT_MAX)
 192                         WARN("Truncation of value to unsigned int");
 193                 break;
 194                 }
 195         case T_LONG:{
 196                 *(long*)addr = PyLong_AsLong(v);
 197                 if ((*(long*)addr == -1) && PyErr_Occurred())
 198                         return -1;
 199                 break;
 200                 }
 201         case T_ULONG:{
 202                 *(unsigned long*)addr = PyLong_AsUnsignedLong(v);
 203                 if ((*(unsigned long*)addr == (unsigned long)-1)
 204                     && PyErr_Occurred()) {
 205                         /* XXX: For compatibility, accept negative int values
 206                            as well. */
 207                         PyErr_Clear();
 208                         *(unsigned long*)addr = PyLong_AsLong(v);
 209                         if ((*(unsigned long*)addr == (unsigned int)-1)
 210                             && PyErr_Occurred())
 211                                 return -1;
 212                         WARN("Writing negative value into unsigned field");
 213                 }
 214                 break;
 215                 }
 216         case T_PYSSIZET:{
 217                 *(Py_ssize_t*)addr = PyLong_AsSsize_t(v);
 218                 if ((*(Py_ssize_t*)addr == (Py_ssize_t)-1)
 219                     && PyErr_Occurred())
 220                                 return -1;
 221                 break;
 222                 }
 223         case T_FLOAT:{
 224                 double double_val = PyFloat_AsDouble(v);
 225                 if ((double_val == -1) && PyErr_Occurred())
 226                         return -1;
 227                 *(float*)addr = (float)double_val;
 228                 break;
 229                 }
 230         case T_DOUBLE:
 231                 *(double*)addr = PyFloat_AsDouble(v);
 232                 if ((*(double*)addr == -1) && PyErr_Occurred())
 233                         return -1;
 234                 break;
 235         case T_OBJECT:
 236         case T_OBJECT_EX:
 237                 Py_XINCREF(v);
 238                 oldv = *(PyObject **)addr;
 239                 *(PyObject **)addr = v;
 240                 Py_XDECREF(oldv);
 241                 break;
 242         case T_CHAR: {
 243                 char *string;
 244                 Py_ssize_t len;
 245
 246                 if (!PyUnicode_Check(v)) {
 247                         PyErr_BadArgument();
 248                         return -1;
 249                 }
 250                 string = _PyUnicode_AsStringAndSize(v, &len);
 251                 if (len != 1) {
 252                         PyErr_BadArgument();
 253                         return -1;
 254                 }
 255                 *(char*)addr = string[0];
 256                 break;
 257                 }
 258 #ifdef HAVE_LONG_LONG
 259         case T_LONGLONG:{
 260                 PY_LONG_LONG value;
 261                 *(PY_LONG_LONG*)addr = value = PyLong_AsLongLong(v);
 262                 if ((value == -1) && PyErr_Occurred())
 263                         return -1;
 264                 break;
 265                 }
 266         case T_ULONGLONG:{
 267                 unsigned PY_LONG_LONG value;
 268                 /* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong
 269                         doesn't ??? */
 270                 if (PyLong_Check(v))
 271                         *(unsigned PY_LONG_LONG*)addr = value = PyLong_AsUnsignedLongLong(v);
 272                 else
 273                         *(unsigned PY_LONG_LONG*)addr = value = PyLong_AsLong(v);
 274                 if ((value == (unsigned PY_LONG_LONG)-1) && PyErr_Occurred())
 275                         return -1;
 276                 break;
 277                 }
 278 #endif /* HAVE_LONG_LONG */
 279         default:
 280                 PyErr_Format(PyExc_SystemError,
 281                              "bad memberdescr type for %s", l->name);
 282                 return -1;
 283         }
 284         return 0;
 285 }