Accessing unaligned structure fields works now on all architectures.

Including unittest.

Lib/ctypes/test/test_byteswap.py

@@ -2,7 +2,6 @@ import sys, unittest, struct, math
 from binascii import hexlify
 
 from ctypes import *
-from ctypes.test import is_resource_enabled
 
 def bin(s):
     return hexlify(buffer(s)).upper()
@@ -222,54 +221,60 @@ class Test(unittest.TestCase):
         s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
         self.failUnlessEqual(bin(s1), bin(s2))
 
-    if is_resource_enabled("unaligned_access"):
+    def test_unaligned_nonnative_struct_fields(self):
+        if sys.byteorder == "little":
+            base = BigEndianStructure
+            fmt = ">b h xi xd"
+        else:
+            base = LittleEndianStructure
+            fmt = "<b h xi xd"
 
-        def test_unaligned_nonnative_struct_fields(self):
+        class S(base):
-            if sys.byteorder == "little":
+            _pack_ = 1
-                base = BigEndianStructure
+            _fields_ = [("b", c_byte),
-                fmt = ">b h xi xd"
-            else:
-                base = LittleEndianStructure
-                fmt = "<b h xi xd"
 
-            class S(base):
+                        ("h", c_short),
-                _pack_ = 1
-                _fields_ = [("b", c_byte),
 
-                            ("h", c_short),
+                        ("_1", c_byte),
+                        ("i", c_int),
 
-                            ("_1", c_byte),
+                        ("_2", c_byte),
-                            ("i", c_int),
+                        ("d", c_double)]
 
-                            ("_2", c_byte),
+        s1 = S()
-                            ("d", c_double)]
+        s1.b = 0x12
+        s1.h = 0x1234
+        s1.i = 0x12345678
+        s1.d = 3.14
+        s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
+        self.failUnlessEqual(bin(s1), bin(s2))
 
-            s1 = S(0x12, 0x1234, 0, 0x12345678, 0, 3.14)
+    def test_unaligned_native_struct_fields(self):
-            s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
+        if sys.byteorder == "little":
-            self.failUnlessEqual(bin(s1), bin(s2))
+            fmt = "<b h xi xd"
+        else:
+            base = LittleEndianStructure
+            fmt = ">b h xi xd"
 
-        def test_unaligned_native_struct_fields(self):
+        class S(Structure):
-            if sys.byteorder == "little":
+            _pack_ = 1
-                fmt = "<b h xi xd"
+            _fields_ = [("b", c_byte),
-            else:
-                base = LittleEndianStructure
-                fmt = ">b h xi xd"
 
-            class S(Structure):
+                        ("h", c_short),
-                _pack_ = 1
-                _fields_ = [("b", c_byte),
 
-                            ("h", c_short),
+                        ("_1", c_byte),
+                        ("i", c_int),
 
-                            ("_1", c_byte),
+                        ("_2", c_byte),
-                            ("i", c_int),
+                        ("d", c_double)]
 
-                            ("_2", c_byte),
+        s1 = S()
-                            ("d", c_double)]
+        s1.b = 0x12
-
+        s1.h = 0x1234
-            s1 = S(0x12, 0x1234, 0, 0x12345678, 0, 3.14)
+        s1.i = 0x12345678
-            s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
+        s1.d = 3.14
-            self.failUnlessEqual(bin(s1), bin(s2))
+        s2 = struct.pack(fmt, 0x12, 0x1234, 0x12345678, 3.14)
+        self.failUnlessEqual(bin(s1), bin(s2))
 
 if __name__ == "__main__":
     unittest.main()

Lib/ctypes/test/test_unaligned_structures.py

@@ -0,0 +1,45 @@
+import sys, unittest
+from ctypes import *
+
+structures = []
+byteswapped_structures = []
+
+
+if sys.byteorder == "little":
+    SwappedStructure = BigEndianStructure
+else:
+    SwappedStructure = LittleEndianStructure
+
+for typ in [c_short, c_int, c_long, c_longlong,
+            c_float, c_double,
+            c_ushort, c_uint, c_ulong, c_ulonglong]:
+    class X(Structure):
+        _pack_ = 1
+        _fields_ = [("pad", c_byte),
+                    ("value", typ)]
+    class Y(SwappedStructure):
+        _pack_ = 1
+        _fields_ = [("pad", c_byte),
+                    ("value", typ)]
+    structures.append(X)
+    byteswapped_structures.append(Y)
+
+class TestStructures(unittest.TestCase):
+    def test_native(self):
+        for typ in structures:
+##            print typ.value
+            self.failUnlessEqual(typ.value.offset, 1)
+            o = typ()
+            o.value = 4
+            self.failUnlessEqual(o.value, 4)
+
+    def test_swapped(self):
+        for typ in byteswapped_structures:
+##            print >> sys.stderr, typ.value
+            self.failUnlessEqual(typ.value.offset, 1)
+            o = typ()
+            o.value = 4
+            self.failUnlessEqual(o.value, 4)
+
+if __name__ == '__main__':
+    unittest.main()

Modules/_ctypes/cfield.c

@@ -536,9 +536,12 @@ static PyObject *
 h_set(void *ptr, PyObject *value, unsigned size)
 {
 	long val;
+	short x;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	*(short *)ptr = (short)SET(*(short *)ptr, (short)val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, (short)val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -550,24 +553,28 @@ h_set_sw(void *ptr, PyObject *value, unsigned size)
 	short field;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	field = SWAP_2(*(short *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_2(field);
 	field = SET(field, (short)val, size);
-	*(short *)ptr = SWAP_2(field);
+	field = SWAP_2(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
 static PyObject *
 h_get(void *ptr, unsigned size)
 {
-	short val = *(short *)ptr;
+	short val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
-	return PyInt_FromLong(val);
+	return PyInt_FromLong((long)val);
 }
 
 static PyObject *
 h_get_sw(void *ptr, unsigned size)
 {
-	short val = *(short *)ptr;
+	short val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_2(val);
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
@@ -577,10 +584,12 @@ static PyObject *
 H_set(void *ptr, PyObject *value, unsigned size)
 {
 	unsigned long val;
+	unsigned short x;
 	if (get_ulong(value, &val) < 0)
 		return NULL;
-	*(unsigned short *)ptr = (unsigned short)SET(*(unsigned short *)ptr,
+	memcpy(&x, ptr, sizeof(x));
-						     (unsigned short)val, size);
+	x = SET(x, (unsigned short)val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -591,9 +600,11 @@ H_set_sw(void *ptr, PyObject *value, unsigned size)
 	unsigned short field;
 	if (get_ulong(value, &val) < 0)
 		return NULL;
-	field = SWAP_2(*(unsigned short *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_2(field);
 	field = SET(field, (unsigned short)val, size);
-	*(unsigned short *)ptr = SWAP_2(field);
+	field = SWAP_2(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
@@ -601,7 +612,8 @@ H_set_sw(void *ptr, PyObject *value, unsigned size)
 static PyObject *
 H_get(void *ptr, unsigned size)
 {
-	unsigned short val = *(unsigned short *)ptr;
+	unsigned short val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
 }
@@ -609,7 +621,8 @@ H_get(void *ptr, unsigned size)
 static PyObject *
 H_get_sw(void *ptr, unsigned size)
 {
-	unsigned short val = *(unsigned short *)ptr;
+	unsigned short val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_2(val);
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
@@ -619,9 +632,12 @@ static PyObject *
 i_set(void *ptr, PyObject *value, unsigned size)
 {
 	long val;
+	int x;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	*(int *)ptr = (int)SET(*(int *)ptr, (int)val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, (int)val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -632,9 +648,11 @@ i_set_sw(void *ptr, PyObject *value, unsigned size)
 	int field;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	field = SWAP_INT(*(int *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_INT(field);
 	field = SET(field, (int)val, size);
-	*(int *)ptr = SWAP_INT(field);
+	field = SWAP_INT(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
@@ -642,7 +660,8 @@ i_set_sw(void *ptr, PyObject *value, unsigned size)
 static PyObject *
 i_get(void *ptr, unsigned size)
 {
-	int val = *(int *)ptr;
+	int val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
 }
@@ -650,7 +669,8 @@ i_get(void *ptr, unsigned size)
 static PyObject *
 i_get_sw(void *ptr, unsigned size)
 {
-	int val = *(int *)ptr;
+	int val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_INT(val);
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
@@ -684,9 +704,12 @@ static PyObject *
 I_set(void *ptr, PyObject *value, unsigned size)
 {
 	unsigned long val;
+	unsigned int x;
 	if (get_ulong(value, &val) < 0)
 		return  NULL;
-	*(unsigned int *)ptr = (unsigned int)SET(*(unsigned int *)ptr, (unsigned int)val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, (unsigned int)val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -697,9 +720,10 @@ I_set_sw(void *ptr, PyObject *value, unsigned size)
 	unsigned int field;
 	if (get_ulong(value, &val) < 0)
 		return  NULL;
-	field = SWAP_INT(*(unsigned int *)ptr);
+	memcpy(&field, ptr, sizeof(field));
 	field = (unsigned int)SET(field, (unsigned int)val, size);
-	*(unsigned int *)ptr = SWAP_INT(field);
+	field = SWAP_INT(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
@@ -707,7 +731,8 @@ I_set_sw(void *ptr, PyObject *value, unsigned size)
 static PyObject *
 I_get(void *ptr, unsigned size)
 {
-	unsigned int val = *(unsigned int *)ptr;
+	unsigned int val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLong(val);
 }
@@ -715,7 +740,8 @@ I_get(void *ptr, unsigned size)
 static PyObject *
 I_get_sw(void *ptr, unsigned size)
 {
-	unsigned int val = *(unsigned int *)ptr;
+	unsigned int val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_INT(val);
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLong(val);
@@ -725,9 +751,12 @@ static PyObject *
 l_set(void *ptr, PyObject *value, unsigned size)
 {
 	long val;
+	long x;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	*(long *)ptr = (long)SET(*(long *)ptr, val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -738,9 +767,11 @@ l_set_sw(void *ptr, PyObject *value, unsigned size)
 	long field;
 	if (get_long(value, &val) < 0)
 		return NULL;
-	field = SWAP_LONG(*(long *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_LONG(field);
 	field = (long)SET(field, val, size);
-	*(long *)ptr = SWAP_LONG(field);
+	field = SWAP_LONG(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
@@ -748,7 +779,8 @@ l_set_sw(void *ptr, PyObject *value, unsigned size)
 static PyObject *
 l_get(void *ptr, unsigned size)
 {
-	long val = *(long *)ptr;
+	long val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
 }
@@ -756,7 +788,8 @@ l_get(void *ptr, unsigned size)
 static PyObject *
 l_get_sw(void *ptr, unsigned size)
 {
-	long val = *(long *)ptr;
+	long val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_LONG(val);
 	GET_BITFIELD(val, size);
 	return PyInt_FromLong(val);
@@ -766,9 +799,12 @@ static PyObject *
 L_set(void *ptr, PyObject *value, unsigned size)
 {
 	unsigned long val;
+	unsigned long x;
 	if (get_ulong(value, &val) < 0)
 		return  NULL;
-	*(unsigned long *)ptr = (unsigned long)SET(*(unsigned long *)ptr, val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -779,9 +815,11 @@ L_set_sw(void *ptr, PyObject *value, unsigned size)
 	unsigned long field;
 	if (get_ulong(value, &val) < 0)
 		return  NULL;
-	field = SWAP_LONG(*(unsigned long *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_LONG(field);
 	field = (unsigned long)SET(field, val, size);
-	*(unsigned long *)ptr = SWAP_LONG(field);
+	field = SWAP_LONG(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
@@ -789,7 +827,8 @@ L_set_sw(void *ptr, PyObject *value, unsigned size)
 static PyObject *
 L_get(void *ptr, unsigned size)
 {
-	unsigned long val = *(unsigned long *)ptr;
+	unsigned long val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLong(val);
 }
@@ -797,7 +836,8 @@ L_get(void *ptr, unsigned size)
 static PyObject *
 L_get_sw(void *ptr, unsigned size)
 {
-	unsigned long val = *(unsigned long *)ptr;
+	unsigned long val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_LONG(val);
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLong(val);
@@ -808,9 +848,12 @@ static PyObject *
 q_set(void *ptr, PyObject *value, unsigned size)
 {
 	PY_LONG_LONG val;
+	PY_LONG_LONG x;
 	if (get_longlong(value, &val) < 0)
 		return NULL;
-	*(PY_LONG_LONG *)ptr = (PY_LONG_LONG)SET(*(PY_LONG_LONG *)ptr, val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -821,16 +864,19 @@ q_set_sw(void *ptr, PyObject *value, unsigned size)
 	PY_LONG_LONG field;
 	if (get_longlong(value, &val) < 0)
 		return NULL;
-	field = SWAP_8(*(PY_LONG_LONG *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_8(field);
 	field = (PY_LONG_LONG)SET(field, val, size);
-	*(PY_LONG_LONG *)ptr = SWAP_8(field);
+	field = SWAP_8(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
 static PyObject *
 q_get(void *ptr, unsigned size)
 {
-	PY_LONG_LONG val = *(PY_LONG_LONG *)ptr;
+	PY_LONG_LONG val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyLong_FromLongLong(val);
 }
@@ -838,7 +884,8 @@ q_get(void *ptr, unsigned size)
 static PyObject *
 q_get_sw(void *ptr, unsigned size)
 {
-	PY_LONG_LONG val = *(PY_LONG_LONG *)ptr;
+	PY_LONG_LONG val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_8(val);
 	GET_BITFIELD(val, size);
 	return PyLong_FromLongLong(val);
@@ -848,9 +895,12 @@ static PyObject *
 Q_set(void *ptr, PyObject *value, unsigned size)
 {
 	unsigned PY_LONG_LONG val;
+	unsigned PY_LONG_LONG x;
 	if (get_ulonglong(value, &val) < 0)
 		return NULL;
-	*(unsigned PY_LONG_LONG *)ptr = (unsigned PY_LONG_LONG)SET(*(unsigned PY_LONG_LONG *)ptr, val, size);
+	memcpy(&x, ptr, sizeof(x));
+	x = SET(x, val, size);
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
@@ -861,16 +911,19 @@ Q_set_sw(void *ptr, PyObject *value, unsigned size)
 	unsigned PY_LONG_LONG field;
 	if (get_ulonglong(value, &val) < 0)
 		return NULL;
-	field = SWAP_8(*(unsigned PY_LONG_LONG *)ptr);
+	memcpy(&field, ptr, sizeof(field));
+	field = SWAP_8(field);
 	field = (unsigned PY_LONG_LONG)SET(field, val, size);
-	*(unsigned PY_LONG_LONG *)ptr = SWAP_8(field);
+	field = SWAP_8(field);
+	memcpy(ptr, &field, sizeof(field));
 	_RET(value);
 }
 
 static PyObject *
 Q_get(void *ptr, unsigned size)
 {
-	unsigned PY_LONG_LONG val = *(unsigned PY_LONG_LONG *)ptr;
+	unsigned PY_LONG_LONG val;
+	memcpy(&val, ptr, sizeof(val));
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLongLong(val);
 }
@@ -878,7 +931,8 @@ Q_get(void *ptr, unsigned size)
 static PyObject *
 Q_get_sw(void *ptr, unsigned size)
 {
-	unsigned PY_LONG_LONG val = *(unsigned PY_LONG_LONG *)ptr;
+	unsigned PY_LONG_LONG val;
+	memcpy(&val, ptr, sizeof(val));
 	val = SWAP_8(val);
 	GET_BITFIELD(val, size);
 	return PyLong_FromUnsignedLongLong(val);
@@ -903,14 +957,16 @@ d_set(void *ptr, PyObject *value, unsigned size)
 			     value->ob_type->tp_name);
 		return NULL;
 	}
-	*(double *)ptr = x;
+	memcpy(ptr, &x, sizeof(double));
 	_RET(value);
 }
 
 static PyObject *
 d_get(void *ptr, unsigned size)
 {
-	return PyFloat_FromDouble(*(double *)ptr);
+	double val;
+	memcpy(&val, ptr, sizeof(val));
+	return PyFloat_FromDouble(val);
 }
 
 static PyObject *
@@ -957,14 +1013,16 @@ f_set(void *ptr, PyObject *value, unsigned size)
 			     value->ob_type->tp_name);
 		return NULL;
 	}
-	*(float *)ptr = x;
+	memcpy(ptr, &x, sizeof(x));
 	_RET(value);
 }
 
 static PyObject *
 f_get(void *ptr, unsigned size)
 {
-	return PyFloat_FromDouble(*(float *)ptr);
+	float val;
+	memcpy(&val, ptr, sizeof(val));
+	return PyFloat_FromDouble(val);
 }
 
 static PyObject *