diff options
| -rw-r--r-- | Lib/test/test_struct.py | 51 | ||||
| -rw-r--r-- | Modules/_struct.c | 8 |
2 files changed, 43 insertions, 16 deletions
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py index 53c0875..919cd63 100644 --- a/Lib/test/test_struct.py +++ b/Lib/test/test_struct.py @@ -3,7 +3,7 @@ import unittest import struct import sys -from test.support import run_unittest +from test.support import run_unittest, cpython_only ISBIGENDIAN = sys.byteorder == "big" IS32BIT = sys.maxsize == 0x7fffffff @@ -40,6 +40,33 @@ def bigendian_to_native(value): return string_reverse(value) class StructTest(unittest.TestCase): + def setUp(self): + # due to missing size_t information from struct, it is assumed that + # sizeof(Py_ssize_t) = sizeof(void*) + self.header = 'PP' + if hasattr(sys, "gettotalrefcount"): + self.header += '2P' + + def check_sizeof(self, format_str, number_of_codes): + def size(fmt): + """Wrapper around struct.calcsize which enforces the alignment + of the end of a structure to the alignment requirement of pointer. + + Note: This wrapper should only be used if a pointer member is + included and no member with a size larger than a pointer exists. + """ + return struct.calcsize(fmt + '0P') + + struct_obj = struct.Struct(format_str) + # The size of 'PyStructObject' + totalsize = size(self.header + '5P') + # The size taken up by the 'formatcode' dynamic array + totalsize += size('3P') * (number_of_codes + 1) + result = sys.getsizeof(struct_obj) + msg = 'wrong size for %s: got %d, expected %d' \ + % (type(struct_obj), result, totalsize) + self.assertEqual(result, totalsize, msg) + def test_isbigendian(self): self.assertEqual((struct.pack('=i', 1)[0] == 0), ISBIGENDIAN) @@ -572,15 +599,19 @@ class StructTest(unittest.TestCase): s = struct.Struct('i') s.__init__('ii') - def test_sizeof(self): - self.assertGreater(sys.getsizeof(struct.Struct('BHILfdspP')), - sys.getsizeof(struct.Struct('B'))) - self.assertGreater(sys.getsizeof(struct.Struct('123B')), - sys.getsizeof(struct.Struct('B'))) - self.assertGreater(sys.getsizeof(struct.Struct('B' * 1234)), - sys.getsizeof(struct.Struct('123B'))) - self.assertGreater(sys.getsizeof(struct.Struct('1234B')), - sys.getsizeof(struct.Struct('123B'))) + @cpython_only + def test__sizeof__(self): + for code in integer_codes: + self.check_sizeof(code, 1) + self.check_sizeof('BHILfdspP', 9) + self.check_sizeof('B' * 1234, 1234) + self.check_sizeof('fd', 2) + self.check_sizeof('xxxxxxxxxxxxxx', 0) + self.check_sizeof('100H', 100) + self.check_sizeof('187s', 1) + self.check_sizeof('20p', 1) + self.check_sizeof('0s', 1) + self.check_sizeof('0c', 0) def test_main(): run_unittest(StructTest) diff --git a/Modules/_struct.c b/Modules/_struct.c index 04692f0..0b20e26 100644 --- a/Modules/_struct.c +++ b/Modules/_struct.c @@ -1756,15 +1756,11 @@ PyDoc_STRVAR(s_sizeof__doc__, "S.__sizeof__() -> size of S in memory, in bytes"); static PyObject * -s_sizeof(PyStructObject *self) +s_sizeof(PyStructObject *self, void *unused) { Py_ssize_t size; - formatcode *code; - size = sizeof(PyStructObject) + sizeof(formatcode); - for (code = self->s_codes; code->fmtdef != NULL; code++) { - size += sizeof(formatcode); - } + size = sizeof(PyStructObject) + sizeof(formatcode) * (self->s_len + 1); return PyLong_FromSsize_t(size); } |