diff --git a/Lib/test/test_bigaddrspace.py b/Lib/test/test_bigaddrspace.py new file mode 100644 index 000000000..50272e996 --- /dev/null +++ b/Lib/test/test_bigaddrspace.py @@ -0,0 +1,98 @@ +""" +These tests are meant to exercise that requests to create objects bigger +than what the address space allows are properly met with an OverflowError +(rather than crash weirdly). + +Primarily, this means 32-bit builds with at least 2 GiB of available memory. +You need to pass the -M option to regrtest (e.g. "-M 2.1G") for tests to +be enabled. +""" + +from test import support +from test.support import bigaddrspacetest, MAX_Py_ssize_t + +import unittest +import operator +import sys + + +class BytesTest(unittest.TestCase): + + @bigaddrspacetest + def test_concat(self): + # Allocate a bytestring that's near the maximum size allowed by + # the address space, and then try to build a new, larger one through + # concatenation. + try: + x = b"x" * (MAX_Py_ssize_t - 128) + self.assertRaises(OverflowError, operator.add, x, b"x" * 128) + finally: + x = None + + @bigaddrspacetest + def test_optimized_concat(self): + try: + x = b"x" * (MAX_Py_ssize_t - 128) + + with self.assertRaises(OverflowError) as cm: + # this statement used a fast path in ceval.c + x = x + b"x" * 128 + + with self.assertRaises(OverflowError) as cm: + # this statement used a fast path in ceval.c + x += b"x" * 128 + finally: + x = None + + @bigaddrspacetest + def test_repeat(self): + try: + x = b"x" * (MAX_Py_ssize_t - 128) + self.assertRaises(OverflowError, operator.mul, x, 128) + finally: + x = None + + +class StrTest(unittest.TestCase): + + unicodesize = 4 + + @bigaddrspacetest + def test_concat(self): + try: + # Create a string that would fill almost the address space + x = "x" * int(MAX_Py_ssize_t // (1.1 * self.unicodesize)) + # Unicode objects trigger MemoryError in case an operation that's + # going to cause a size overflow is executed + self.assertRaises(MemoryError, operator.add, x, x) + finally: + x = None + + @bigaddrspacetest + def test_optimized_concat(self): + try: + x = "x" * int(MAX_Py_ssize_t // (1.1 * self.unicodesize)) + + with self.assertRaises(MemoryError) as cm: + # this statement uses a fast path in ceval.c + x = x + x + + with self.assertRaises(MemoryError) as cm: + # this statement uses a fast path in ceval.c + x += x + finally: + x = None + + @bigaddrspacetest + def test_repeat(self): + try: + x = "x" * int(MAX_Py_ssize_t // (1.1 * self.unicodesize)) + self.assertRaises(MemoryError, operator.mul, x, 2) + finally: + x = None + + +if __name__ == '__main__': + if len(sys.argv) > 1: + support.set_memlimit(sys.argv[1]) + unittest.main()