diff options
-rw-r--r-- | tests/basics/builtin_range_maxsize.py | 38 | ||||
-rw-r--r-- | tests/cpydiff/types_range_limits.py | 26 |
2 files changed, 64 insertions, 0 deletions
diff --git a/tests/basics/builtin_range_maxsize.py b/tests/basics/builtin_range_maxsize.py new file mode 100644 index 000000000..b0f3a5e51 --- /dev/null +++ b/tests/basics/builtin_range_maxsize.py @@ -0,0 +1,38 @@ +try: + from sys import maxsize +except ImportError: + print("SKIP") + raise SystemExit + +# Test the range builtin at extreme values. (https://github.com/micropython/micropython/issues/17684) +# +# This is written using asserts instead of prints because the value of `maxsize` differs. +# +# Numbers & counts right up against the max of mp_int_t also cause overflows, such as +# objrange.c:115:14: runtime error: signed integer overflow: 9223372036854775807 + 1 cannot be represented in type 'long int' +# so just avoid them for the purposes of this test. + +r = range(-maxsize + 1, -1) +assert r.start == -maxsize + 1 +assert r.stop == -1 +assert r[0] == -maxsize + 1 +assert r[1] == -maxsize + 2 +assert r[-1] == -2 +assert r[-2] == -3 + +ir = iter(r) +assert next(ir) == -maxsize + 1 +assert next(ir) == -maxsize + 2 + +r = range(0, maxsize - 1) +assert len(r) == maxsize - 1 +assert r.stop == maxsize - 1 + +r = range(maxsize, 0, -1) +assert len(r) == maxsize +assert r.start == maxsize +assert r[0] == maxsize +assert r[1] == maxsize - 1 +ir = iter(r) +assert next(ir) == maxsize +assert next(ir) == maxsize - 1 diff --git a/tests/cpydiff/types_range_limits.py b/tests/cpydiff/types_range_limits.py new file mode 100644 index 000000000..e53d5fd40 --- /dev/null +++ b/tests/cpydiff/types_range_limits.py @@ -0,0 +1,26 @@ +""" +categories: Types,range +description: Range objects with large start or stop arguments misbehave. +cause: Intermediate calculations overflow the C mp_int_t type +workaround: Avoid using such ranges +""" + +from sys import maxsize + +# A range including `maxsize-1` cannot be created +try: + print(range(-maxsize - 1, 0)) +except OverflowError: + print("OverflowError") + +# A range with `stop-start` exceeding sys.maxsize has incorrect len(), while CPython cannot calculate len(). +try: + print(len(range(-maxsize, maxsize))) +except OverflowError: + print("OverflowError") + +# A range with `stop-start` exceeding sys.maxsize has incorrect len() +try: + print(len(range(-maxsize, maxsize, maxsize))) +except OverflowError: + print("OverflowError") |