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_BOOL:

    65 		v = PyBool_FromLong(*(char*)addr);

    66 		break;

    67 	case T_BYTE:

    68 		v = PyInt_FromLong(*(char*)addr);

    69 		break;

    70 	case T_UBYTE:

    71 		v = PyLong_FromUnsignedLong(*(unsigned char*)addr);

    72 		break;

    73 	case T_SHORT:

    74 		v = PyInt_FromLong(*(short*)addr);

    75 		break;

    76 	case T_USHORT:

    77 		v = PyLong_FromUnsignedLong(*(unsigned short*)addr);

    78 		break;

    79 	case T_INT:

    80 		v = PyInt_FromLong(*(int*)addr);

    81 		break;

    82 	case T_UINT:

    83 		v = PyLong_FromUnsignedLong(*(unsigned int*)addr);

    84 		break;

    85 	case T_LONG:

    86 		v = PyInt_FromLong(*(long*)addr);

    87 		break;

    88 	case T_ULONG:

    89 		v = PyLong_FromUnsignedLong(*(unsigned long*)addr);

    90 		break;

    91 	case T_PYSSIZET:

    92 		v = PyInt_FromSsize_t(*(Py_ssize_t*)addr);

    93 		break;

    94 	case T_FLOAT:

    95 		v = PyFloat_FromDouble((double)*(float*)addr);

    96 		break;

    97 	case T_DOUBLE:

    98 		v = PyFloat_FromDouble(*(double*)addr);

    99 		break;

   100 	case T_STRING:

   101 		if (*(char**)addr == NULL) {

   102 			Py_INCREF(Py_None);

   103 			v = Py_None;

   104 		}

   105 		else

   106 			v = PyString_FromString(*(char**)addr);

   107 		break;

   108 	case T_STRING_INPLACE:

   109 		v = PyString_FromString((char*)addr);

   110 		break;

   111 	case T_CHAR:

   112 		v = PyString_FromStringAndSize((char*)addr, 1);

   113 		break;

   114 	case T_OBJECT:

   115 		v = *(PyObject **)addr;

   116 		if (v == NULL)

   117 			v = Py_None;

   118 		Py_INCREF(v);

   119 		break;

   120 	case T_OBJECT_EX:

   121 		v = *(PyObject **)addr;

   122 		if (v == NULL)

   123 			PyErr_SetString(PyExc_AttributeError, l->name);

   124 		Py_XINCREF(v);

   125 		break;

   126 #ifdef HAVE_LONG_LONG

   127 	case T_LONGLONG:

   128 		v = PyLong_FromLongLong(*(PY_LONG_LONG *)addr);

   129 		break;

   130 	case T_ULONGLONG:

   131 		v = PyLong_FromUnsignedLongLong(*(unsigned PY_LONG_LONG *)addr);

   132 		break;

   133 #endif /* HAVE_LONG_LONG */

   134 	default:

   135 		PyErr_SetString(PyExc_SystemError, "bad memberdescr type");

   136 		v = NULL;

   137 	}

   138 	return v;

   139 }

   140 

   141 int

   142 PyMember_Set(char *addr, struct memberlist *mlist, const char *name, PyObject *v)

   143 {

   144 	struct memberlist *l;

   145 

   146 	for (l = mlist; l->name != NULL; l++) {

   147 		if (strcmp(l->name, name) == 0) {

   148 			PyMemberDef copy;

   149 			copy.name = l->name;

   150 			copy.type = l->type;

   151 			copy.offset = l->offset;

   152 			copy.flags = l->flags;

   153 			copy.doc = NULL;

   154 			return PyMember_SetOne(addr, &copy, v);

   155 		}

   156 	}

   157 

   158 	PyErr_SetString(PyExc_AttributeError, name);

   159 	return -1;

   160 }

   161 

   162 #define WARN(msg)					\

   163     do {						\

   164 	if (PyErr_Warn(PyExc_RuntimeWarning, msg) < 0)	\

   165 		return -1;				\

   166     } while (0)

   167 

   168 int

   169 PyMember_SetOne(char *addr, PyMemberDef *l, PyObject *v)

   170 {

   171 	PyObject *oldv;

   172 

   173 	if ((l->flags & READONLY) || l->type == T_STRING)

   174 	{

   175 		PyErr_SetString(PyExc_TypeError, "readonly attribute");

   176 		return -1;

   177 	}

   178 	if ((l->flags & PY_WRITE_RESTRICTED) && PyEval_GetRestricted()) {

   179 		PyErr_SetString(PyExc_RuntimeError, "restricted attribute");

   180 		return -1;

   181 	}

   182 	if (v == NULL && l->type != T_OBJECT_EX && l->type != T_OBJECT) {

   183 		PyErr_SetString(PyExc_TypeError,

   184 				"can't delete numeric/char attribute");

   185 		return -1;

   186 	}

   187 	addr += l->offset;

   188 	switch (l->type) {

   189 	case T_BOOL:{

   190 		if (!PyBool_Check(v)) {

   191 			PyErr_SetString(PyExc_TypeError,

   192 					"attribute value type must be bool");

   193 			return -1;

   194 		}

   195 		if (v == Py_True)

   196 			*(char*)addr = (char) 1;

   197 		else

   198 			*(char*)addr = (char) 0;

   199 		break;

   200 		}

   201 	case T_BYTE:{

   202 		long long_val = PyInt_AsLong(v);

   203 		if ((long_val == -1) && PyErr_Occurred())

   204 			return -1;

   205 		*(char*)addr = (char)long_val;

   206 		/* XXX: For compatibility, only warn about truncations

   207 		   for now. */

   208 		if ((long_val > CHAR_MAX) || (long_val < CHAR_MIN))

   209 			WARN("Truncation of value to char");

   210 		break;

   211 		}

   212 	case T_UBYTE:{

   213 		long long_val = PyInt_AsLong(v);

   214 		if ((long_val == -1) && PyErr_Occurred())

   215 			return -1;

   216 		*(unsigned char*)addr = (unsigned char)long_val;

   217 		if ((long_val > UCHAR_MAX) || (long_val < 0))

   218 			WARN("Truncation of value to unsigned char");

   219 		break;

   220 		}

   221 	case T_SHORT:{

   222 		long long_val = PyInt_AsLong(v);

   223 		if ((long_val == -1) && PyErr_Occurred())

   224 			return -1;

   225 		*(short*)addr = (short)long_val;

   226 		if ((long_val > SHRT_MAX) || (long_val < SHRT_MIN))

   227 			WARN("Truncation of value to short");

   228 		break;

   229 		}

   230 	case T_USHORT:{

   231 		long long_val = PyInt_AsLong(v);

   232 		if ((long_val == -1) && PyErr_Occurred())

   233 			return -1;

   234 		*(unsigned short*)addr = (unsigned short)long_val;

   235 		if ((long_val > USHRT_MAX) || (long_val < 0))

   236 			WARN("Truncation of value to unsigned short");

   237 		break;

   238 		}

   239   	case T_INT:{

   240 		long long_val = PyInt_AsLong(v);

   241 		if ((long_val == -1) && PyErr_Occurred())

   242 			return -1;

   243 		*(int *)addr = (int)long_val;

   244 		if ((long_val > INT_MAX) || (long_val < INT_MIN))

   245 			WARN("Truncation of value to int");

   246 		break;

   247 		}

   248 	case T_UINT:{

   249 		unsigned long ulong_val = PyLong_AsUnsignedLong(v);

   250 		if ((ulong_val == (unsigned int)-1) && PyErr_Occurred()) {

   251 			/* XXX: For compatibility, accept negative int values

   252 			   as well. */

   253 			PyErr_Clear();

   254 			ulong_val = PyLong_AsLong(v);

   255 			if ((ulong_val == (unsigned int)-1) && PyErr_Occurred())

   256 				return -1;

   257 			*(unsigned int *)addr = (unsigned int)ulong_val;

   258 			WARN("Writing negative value into unsigned field");

   259 		} else

   260 			*(unsigned int *)addr = (unsigned int)ulong_val;

   261 		if (ulong_val > UINT_MAX)

   262 			WARN("Truncation of value to unsigned int");

   263 		break;

   264 		}

   265 	case T_LONG:{

   266 		*(long*)addr = PyLong_AsLong(v);

   267 		if ((*(long*)addr == -1) && PyErr_Occurred())

   268 			return -1;

   269 		break;

   270 		}

   271 	case T_ULONG:{

   272 		*(unsigned long*)addr = PyLong_AsUnsignedLong(v);

   273 		if ((*(unsigned long*)addr == (unsigned long)-1)

   274 		    && PyErr_Occurred()) {

   275 			/* XXX: For compatibility, accept negative int values

   276 			   as well. */

   277 			PyErr_Clear();

   278 			*(unsigned long*)addr = PyLong_AsLong(v);

   279 			if ((*(unsigned long*)addr == (unsigned int)-1)

   280 			    && PyErr_Occurred())

   281 				return -1;

   282 			WARN("Writing negative value into unsigned field");

   283 		}

   284 		break;

   285 		}

   286 	case T_PYSSIZET:{

   287 		*(Py_ssize_t*)addr = PyInt_AsSsize_t(v);

   288 		if ((*(Py_ssize_t*)addr == (Py_ssize_t)-1)

   289 		    && PyErr_Occurred())

   290 				return -1;

   291 		break;

   292 		}

   293 	case T_FLOAT:{

   294 		double double_val = PyFloat_AsDouble(v);

   295 		if ((double_val == -1) && PyErr_Occurred())

   296 			return -1;

   297 		*(float*)addr = (float)double_val;

   298 		break;

   299 		}

   300 	case T_DOUBLE:

   301 		*(double*)addr = PyFloat_AsDouble(v);

   302 		if ((*(double*)addr == -1) && PyErr_Occurred())

   303 			return -1;

   304 		break;

   305 	case T_OBJECT:

   306 	case T_OBJECT_EX:

   307 		Py_XINCREF(v);

   308 		oldv = *(PyObject **)addr;

   309 		*(PyObject **)addr = v;

   310 		Py_XDECREF(oldv);

   311 		break;

   312 	case T_CHAR:

   313 		if (PyString_Check(v) && PyString_Size(v) == 1) {

   314 			*(char*)addr = PyString_AsString(v)[0];

   315 		}

   316 		else {

   317 			PyErr_BadArgument();

   318 			return -1;

   319 		}

   320 		break;

   321 #ifdef HAVE_LONG_LONG

   322 	case T_LONGLONG:{

   323 		PY_LONG_LONG value;

   324 		*(PY_LONG_LONG*)addr = value = PyLong_AsLongLong(v);

   325 		if ((value == -1) && PyErr_Occurred())

   326 			return -1;

   327 		break;

   328 		}

   329 	case T_ULONGLONG:{

   330 		unsigned PY_LONG_LONG value;

   331 		/* ??? PyLong_AsLongLong accepts an int, but PyLong_AsUnsignedLongLong

   332 			doesn't ??? */

   333 		if (PyLong_Check(v))

   334 			*(unsigned PY_LONG_LONG*)addr = value = PyLong_AsUnsignedLongLong(v);

   335 		else

   336 			*(unsigned PY_LONG_LONG*)addr = value = PyInt_AsLong(v);

   337 		if ((value == (unsigned PY_LONG_LONG)-1) && PyErr_Occurred())

   338 			return -1;

   339 		break;

   340 		}

   341 #endif /* HAVE_LONG_LONG */

   342 	default:

   343 		PyErr_Format(PyExc_SystemError,

   344 			     "bad memberdescr type for %s", l->name);

   345 		return -1;

   346 	}

   347 	return 0;

   348 }