(root)/
Python-3.12.0/
Python/
structmember.c
       1  
       2  /* Map C struct members to Python object attributes */
       3  
       4  #include "Python.h"
       5  #include "structmember.h"         // PyMemberDef
       6  
       7  PyObject *
       8  PyMember_GetOne(const char *obj_addr, PyMemberDef *l)
       9  {
      10      PyObject *v;
      11      if (l->flags & Py_RELATIVE_OFFSET) {
      12          PyErr_SetString(
      13              PyExc_SystemError,
      14              "PyMember_GetOne used with Py_RELATIVE_OFFSET");
      15          return NULL;
      16      }
      17  
      18      const char* addr = obj_addr + l->offset;
      19      switch (l->type) {
      20      case T_BOOL:
      21          v = PyBool_FromLong(*(char*)addr);
      22          break;
      23      case T_BYTE:
      24          v = PyLong_FromLong(*(char*)addr);
      25          break;
      26      case T_UBYTE:
      27          v = PyLong_FromUnsignedLong(*(unsigned char*)addr);
      28          break;
      29      case T_SHORT:
      30          v = PyLong_FromLong(*(short*)addr);
      31          break;
      32      case T_USHORT:
      33          v = PyLong_FromUnsignedLong(*(unsigned short*)addr);
      34          break;
      35      case T_INT:
      36          v = PyLong_FromLong(*(int*)addr);
      37          break;
      38      case T_UINT:
      39          v = PyLong_FromUnsignedLong(*(unsigned int*)addr);
      40          break;
      41      case T_LONG:
      42          v = PyLong_FromLong(*(long*)addr);
      43          break;
      44      case T_ULONG:
      45          v = PyLong_FromUnsignedLong(*(unsigned long*)addr);
      46          break;
      47      case T_PYSSIZET:
      48          v = PyLong_FromSsize_t(*(Py_ssize_t*)addr);
      49          break;
      50      case T_FLOAT:
      51          v = PyFloat_FromDouble((double)*(float*)addr);
      52          break;
      53      case T_DOUBLE:
      54          v = PyFloat_FromDouble(*(double*)addr);
      55          break;
      56      case T_STRING:
      57          if (*(char**)addr == NULL) {
      58              v = Py_NewRef(Py_None);
      59          }
      60          else
      61              v = PyUnicode_FromString(*(char**)addr);
      62          break;
      63      case T_STRING_INPLACE:
      64          v = PyUnicode_FromString((char*)addr);
      65          break;
      66      case T_CHAR:
      67          v = PyUnicode_FromStringAndSize((char*)addr, 1);
      68          break;
      69      case T_OBJECT:
      70          v = *(PyObject **)addr;
      71          if (v == NULL)
      72              v = Py_None;
      73          Py_INCREF(v);
      74          break;
      75      case T_OBJECT_EX:
      76          v = *(PyObject **)addr;
      77          if (v == NULL) {
      78              PyObject *obj = (PyObject *)obj_addr;
      79              PyTypeObject *tp = Py_TYPE(obj);
      80              PyErr_Format(PyExc_AttributeError,
      81                           "'%.200s' object has no attribute '%s'",
      82                           tp->tp_name, l->name);
      83          }
      84          Py_XINCREF(v);
      85          break;
      86      case T_LONGLONG:
      87          v = PyLong_FromLongLong(*(long long *)addr);
      88          break;
      89      case T_ULONGLONG:
      90          v = PyLong_FromUnsignedLongLong(*(unsigned long long *)addr);
      91          break;
      92      case T_NONE:
      93          v = Py_NewRef(Py_None);
      94          break;
      95      default:
      96          PyErr_SetString(PyExc_SystemError, "bad memberdescr type");
      97          v = NULL;
      98      }
      99      return v;
     100  }
     101  
     102  #define WARN(msg)                                               \
     103      do {                                                        \
     104      if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0)         \
     105          return -1;                                              \
     106      } while (0)
     107  
     108  int
     109  PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
     110  {
     111      PyObject *oldv;
     112      if (l->flags & Py_RELATIVE_OFFSET) {
     113          PyErr_SetString(
     114              PyExc_SystemError,
     115              "PyMember_SetOne used with Py_RELATIVE_OFFSET");
     116          return -1;
     117      }
     118  
     119      addr += l->offset;
     120  
     121      if ((l->flags & READONLY))
     122      {
     123          PyErr_SetString(PyExc_AttributeError, "readonly attribute");
     124          return -1;
     125      }
     126      if (v == NULL) {
     127          if (l->type == T_OBJECT_EX) {
     128              /* Check if the attribute is set. */
     129              if (*(PyObject **)addr == NULL) {
     130                  PyErr_SetString(PyExc_AttributeError, l->name);
     131                  return -1;
     132              }
     133          }
     134          else if (l->type != T_OBJECT) {
     135              PyErr_SetString(PyExc_TypeError,
     136                              "can't delete numeric/char attribute");
     137              return -1;
     138          }
     139      }
     140      switch (l->type) {
     141      case T_BOOL:{
     142          if (!PyBool_Check(v)) {
     143              PyErr_SetString(PyExc_TypeError,
     144                              "attribute value type must be bool");
     145              return -1;
     146          }
     147          if (v == Py_True)
     148              *(char*)addr = (char) 1;
     149          else
     150              *(char*)addr = (char) 0;
     151          break;
     152          }
     153      case T_BYTE:{
     154          long long_val = PyLong_AsLong(v);
     155          if ((long_val == -1) && PyErr_Occurred())
     156              return -1;
     157          *(char*)addr = (char)long_val;
     158          /* XXX: For compatibility, only warn about truncations
     159             for now. */
     160          if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN))
     161              WARN("Truncation of value to char");
     162          break;
     163          }
     164      case T_UBYTE:{
     165          long long_val = PyLong_AsLong(v);
     166          if ((long_val == -1) && PyErr_Occurred())
     167              return -1;
     168          *(unsigned char*)addr = (unsigned char)long_val;
     169          if ((long_val > UCHAR_MAX) || (long_val < 0))
     170              WARN("Truncation of value to unsigned char");
     171          break;
     172          }
     173      case T_SHORT:{
     174          long long_val = PyLong_AsLong(v);
     175          if ((long_val == -1) && PyErr_Occurred())
     176              return -1;
     177          *(short*)addr = (short)long_val;
     178          if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN))
     179              WARN("Truncation of value to short");
     180          break;
     181          }
     182      case T_USHORT:{
     183          long long_val = PyLong_AsLong(v);
     184          if ((long_val == -1) && PyErr_Occurred())
     185              return -1;
     186          *(unsigned short*)addr = (unsigned short)long_val;
     187          if ((long_val > USHRT_MAX) || (long_val < 0))
     188              WARN("Truncation of value to unsigned short");
     189          break;
     190          }
     191      case T_INT:{
     192          long long_val = PyLong_AsLong(v);
     193          if ((long_val == -1) && PyErr_Occurred())
     194              return -1;
     195          *(int *)addr = (int)long_val;
     196          if ((long_val > INT_MAX) || (long_val < INT_MIN))
     197              WARN("Truncation of value to int");
     198          break;
     199          }
     200      case T_UINT:{
     201          unsigned long ulong_val = PyLong_AsUnsignedLong(v);
     202          if ((ulong_val == (unsigned long)-1) && PyErr_Occurred()) {
     203              /* XXX: For compatibility, accept negative int values
     204                 as well. */
     205              PyErr_Clear();
     206              ulong_val = PyLong_AsLong(v);
     207              if ((ulong_val == (unsigned long)-1) &&
     208                  PyErr_Occurred())
     209                  return -1;
     210              *(unsigned int *)addr = (unsigned int)ulong_val;
     211              WARN("Writing negative value into unsigned field");
     212          } else
     213              *(unsigned int *)addr = (unsigned int)ulong_val;
     214          if (ulong_val > UINT_MAX)
     215              WARN("Truncation of value to unsigned int");
     216          break;
     217          }
     218      case T_LONG:{
     219          *(long*)addr = PyLong_AsLong(v);
     220          if ((*(long*)addr == -1) && PyErr_Occurred())
     221              return -1;
     222          break;
     223          }
     224      case T_ULONG:{
     225          *(unsigned long*)addr = PyLong_AsUnsignedLong(v);
     226          if ((*(unsigned long*)addr == (unsigned long)-1)
     227              && PyErr_Occurred()) {
     228              /* XXX: For compatibility, accept negative int values
     229                 as well. */
     230              PyErr_Clear();
     231              *(unsigned long*)addr = PyLong_AsLong(v);
     232              if ((*(unsigned long*)addr == (unsigned long)-1)
     233                  && PyErr_Occurred())
     234                  return -1;
     235              WARN("Writing negative value into unsigned field");
     236          }
     237          break;
     238          }
     239      case T_PYSSIZET:{
     240          *(Py_ssize_t*)addr = PyLong_AsSsize_t(v);
     241          if ((*(Py_ssize_t*)addr == (Py_ssize_t)-1)
     242              && PyErr_Occurred())
     243                          return -1;
     244          break;
     245          }
     246      case T_FLOAT:{
     247          double double_val = PyFloat_AsDouble(v);
     248          if ((double_val == -1) && PyErr_Occurred())
     249              return -1;
     250          *(float*)addr = (float)double_val;
     251          break;
     252          }
     253      case T_DOUBLE:
     254          *(double*)addr = PyFloat_AsDouble(v);
     255          if ((*(double*)addr == -1) && PyErr_Occurred())
     256              return -1;
     257          break;
     258      case T_OBJECT:
     259      case T_OBJECT_EX:
     260          oldv = *(PyObject **)addr;
     261          *(PyObject **)addr = Py_XNewRef(v);
     262          Py_XDECREF(oldv);
     263          break;
     264      case T_CHAR: {
     265          const char *string;
     266          Py_ssize_t len;
     267  
     268          string = PyUnicode_AsUTF8AndSize(v, &len);
     269          if (string == NULL || len != 1) {
     270              PyErr_BadArgument();
     271              return -1;
     272          }
     273          *(char*)addr = string[0];
     274          break;
     275          }
     276      case T_STRING:
     277      case T_STRING_INPLACE:
     278          PyErr_SetString(PyExc_TypeError, "readonly attribute");
     279          return -1;
     280      case T_LONGLONG:{
     281          long long value;
     282          *(long long*)addr = value = PyLong_AsLongLong(v);
     283          if ((value == -1) && PyErr_Occurred())
     284              return -1;
     285          break;
     286          }
     287      case T_ULONGLONG:{
     288          unsigned long long value;
     289          /* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong
     290              doesn't ??? */
     291          if (PyLong_Check(v))
     292              *(unsigned long long*)addr = value = PyLong_AsUnsignedLongLong(v);
     293          else
     294              *(unsigned long long*)addr = value = PyLong_AsLong(v);
     295          if ((value == (unsigned long long)-1) && PyErr_Occurred())
     296              return -1;
     297          break;
     298          }
     299      default:
     300          PyErr_Format(PyExc_SystemError,
     301                       "bad memberdescr type for %s", l->name);
     302          return -1;
     303      }
     304      return 0;
     305  }