Skip to content
Permalink
main
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

cpython/Python/structmember.c

Go to file
 
 
Cannot retrieve contributors at this time
293 lines (284 sloc) 8.79 KB
Raw Blame
Open in GitHub Desktop
/* Map C struct members to Python object attributes */
#include "Python.h"
#include "structmember.h" // PyMemberDef
PyObject *
PyMember_GetOne(const char *obj_addr, PyMemberDef *l)
{
PyObject *v;
const char* addr = obj_addr + l->offset;
switch (l->type) {
case T_BOOL:
v = PyBool_FromLong(*(char*)addr);
break;
case T_BYTE:
v = PyLong_FromLong(*(char*)addr);
break;
case T_UBYTE:
v = PyLong_FromUnsignedLong(*(unsigned char*)addr);
break;
case T_SHORT:
v = PyLong_FromLong(*(short*)addr);
break;
case T_USHORT:
v = PyLong_FromUnsignedLong(*(unsigned short*)addr);
break;
case T_INT:
v = PyLong_FromLong(*(int*)addr);
break;
case T_UINT:
v = PyLong_FromUnsignedLong(*(unsigned int*)addr);
break;
case T_LONG:
v = PyLong_FromLong(*(long*)addr);
break;
case T_ULONG:
v = PyLong_FromUnsignedLong(*(unsigned long*)addr);
break;
case T_PYSSIZET:
v = PyLong_FromSsize_t(*(Py_ssize_t*)addr);
break;
case T_FLOAT:
v = PyFloat_FromDouble((double)*(float*)addr);
break;
case T_DOUBLE:
v = PyFloat_FromDouble(*(double*)addr);
break;
case T_STRING:
if (*(char**)addr == NULL) {
v = Py_NewRef(Py_None);
}
else
v = PyUnicode_FromString(*(char**)addr);
break;
case T_STRING_INPLACE:
v = PyUnicode_FromString((char*)addr);
break;
case T_CHAR:
v = PyUnicode_FromStringAndSize((char*)addr, 1);
break;
case T_OBJECT:
v = *(PyObject **)addr;
if (v == NULL)
v = Py_None;
Py_INCREF(v);
break;
case T_OBJECT_EX:
v = *(PyObject **)addr;
if (v == NULL) {
PyObject *obj = (PyObject *)obj_addr;
PyTypeObject *tp = Py_TYPE(obj);
PyErr_Format(PyExc_AttributeError,
"'%.200s' object has no attribute '%s'",
tp->tp_name, l->name);
}
Py_XINCREF(v);
break;
case T_LONGLONG:
v = PyLong_FromLongLong(*(long long *)addr);
break;
case T_ULONGLONG:
v = PyLong_FromUnsignedLongLong(*(unsigned long long *)addr);
break;
case T_NONE:
v = Py_NewRef(Py_None);
break;
default:
PyErr_SetString(PyExc_SystemError, "bad memberdescr type");
v = NULL;
}
return v;
}
#define WARN(msg) \
do { \
if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0) \
return -1; \
} while (0)
int
PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)
{
PyObject *oldv;
addr += l->offset;
if ((l->flags & READONLY))
{
PyErr_SetString(PyExc_AttributeError, "readonly attribute");
return -1;
}
if (v == NULL) {
if (l->type == T_OBJECT_EX) {
/* Check if the attribute is set. */
if (*(PyObject **)addr == NULL) {
PyErr_SetString(PyExc_AttributeError, l->name);
return -1;
}
}
else if (l->type != T_OBJECT) {
PyErr_SetString(PyExc_TypeError,
"can't delete numeric/char attribute");
return -1;
}
}
switch (l->type) {
case T_BOOL:{
if (!PyBool_Check(v)) {
PyErr_SetString(PyExc_TypeError,
"attribute value type must be bool");
return -1;
}
if (v == Py_True)
*(char*)addr = (char) 1;
else
*(char*)addr = (char) 0;
break;
}
case T_BYTE:{
long long_val = PyLong_AsLong(v);
if ((long_val == -1) && PyErr_Occurred())
return -1;
*(char*)addr = (char)long_val;
/* XXX: For compatibility, only warn about truncations
for now. */
if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN))
WARN("Truncation of value to char");
break;
}
case T_UBYTE:{
long long_val = PyLong_AsLong(v);
if ((long_val == -1) && PyErr_Occurred())
return -1;
*(unsigned char*)addr = (unsigned char)long_val;
if ((long_val > UCHAR_MAX) || (long_val < 0))
WARN("Truncation of value to unsigned char");
break;
}
case T_SHORT:{
long long_val = PyLong_AsLong(v);
if ((long_val == -1) && PyErr_Occurred())
return -1;
*(short*)addr = (short)long_val;
if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN))
WARN("Truncation of value to short");
break;
}
case T_USHORT:{
long long_val = PyLong_AsLong(v);
if ((long_val == -1) && PyErr_Occurred())
return -1;
*(unsigned short*)addr = (unsigned short)long_val;
if ((long_val > USHRT_MAX) || (long_val < 0))
WARN("Truncation of value to unsigned short");
break;
}
case T_INT:{
long long_val = PyLong_AsLong(v);
if ((long_val == -1) && PyErr_Occurred())
return -1;
*(int *)addr = (int)long_val;
if ((long_val > INT_MAX) || (long_val < INT_MIN))
WARN("Truncation of value to int");
break;
}
case T_UINT:{
unsigned long ulong_val = PyLong_AsUnsignedLong(v);
if ((ulong_val == (unsigned long)-1) && PyErr_Occurred()) {
/* XXX: For compatibility, accept negative int values
as well. */
PyErr_Clear();
ulong_val = PyLong_AsLong(v);
if ((ulong_val == (unsigned long)-1) &&
PyErr_Occurred())
return -1;
*(unsigned int *)addr = (unsigned int)ulong_val;
WARN("Writing negative value into unsigned field");
} else
*(unsigned int *)addr = (unsigned int)ulong_val;
if (ulong_val > UINT_MAX)
WARN("Truncation of value to unsigned int");
break;
}
case T_LONG:{
*(long*)addr = PyLong_AsLong(v);
if ((*(long*)addr == -1) && PyErr_Occurred())
return -1;
break;
}
case T_ULONG:{
*(unsigned long*)addr = PyLong_AsUnsignedLong(v);
if ((*(unsigned long*)addr == (unsigned long)-1)
&& PyErr_Occurred()) {
/* XXX: For compatibility, accept negative int values
as well. */
PyErr_Clear();
*(unsigned long*)addr = PyLong_AsLong(v);
if ((*(unsigned long*)addr == (unsigned long)-1)
&& PyErr_Occurred())
return -1;
WARN("Writing negative value into unsigned field");
}
break;
}
case T_PYSSIZET:{
*(Py_ssize_t*)addr = PyLong_AsSsize_t(v);
if ((*(Py_ssize_t*)addr == (Py_ssize_t)-1)
&& PyErr_Occurred())
return -1;
break;
}
case T_FLOAT:{
double double_val = PyFloat_AsDouble(v);
if ((double_val == -1) && PyErr_Occurred())
return -1;
*(float*)addr = (float)double_val;
break;
}
case T_DOUBLE:
*(double*)addr = PyFloat_AsDouble(v);
if ((*(double*)addr == -1) && PyErr_Occurred())
return -1;
break;
case T_OBJECT:
case T_OBJECT_EX:
oldv = *(PyObject **)addr;
*(PyObject **)addr = Py_XNewRef(v);
Py_XDECREF(oldv);
break;
case T_CHAR: {
const char *string;
Py_ssize_t len;
string = PyUnicode_AsUTF8AndSize(v, &len);
if (string == NULL || len != 1) {
PyErr_BadArgument();
return -1;
}
*(char*)addr = string[0];
break;
}
case T_STRING:
case T_STRING_INPLACE:
PyErr_SetString(PyExc_TypeError, "readonly attribute");
return -1;
case T_LONGLONG:{
long long value;
*(long long*)addr = value = PyLong_AsLongLong(v);
if ((value == -1) && PyErr_Occurred())
return -1;
break;
}
case T_ULONGLONG:{
unsigned long long value;
/* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong
doesn't ??? */
if (PyLong_Check(v))
*(unsigned long long*)addr = value = PyLong_AsUnsignedLongLong(v);
else
*(unsigned long long*)addr = value = PyLong_AsLong(v);
if ((value == (unsigned long long)-1) && PyErr_Occurred())
return -1;
break;
}
default:
PyErr_Format(PyExc_SystemError,
"bad memberdescr type for %s", l->name);
return -1;
}
return 0;
}