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https://github.com/RustPython/RustPython.git
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Changjoon
96011dd218
PR #7727 added an overflow guard in float_pow's negative-base non-integer-exponent branch (which delegates to complex_pow). The remaining else branch — covering positive base or negative-base integer exponent — directly returned v1.powf(v2) without inspecting the result, so finite inputs that produced an out-of-range value silently leaked f64::INFINITY (or -INFINITY) instead of raising. Examples that now raise OverflowError as in CPython: pow(2.0, 2000) pow(10.0, 400) pow(-2.0, 2001) pow(0.5, -2000) pow(1e150, 3) Mirror the inline overflow guard already used in complex.rs::complex_pow: when the result is infinite but neither input is, raise OverflowError. The both-finite check preserves intentional infinities like pow(inf, 2.0). Closes #7729
185 lines
5.6 KiB
Python
185 lines
5.6 KiB
Python
from testutils import assert_equal, assert_raises
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assert pow(3, 2) == 9
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assert pow(5, 3, 100) == 25
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assert pow(41, 7, 2) == 1
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assert pow(7, 2, 49) == 0
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assert pow(0, 0) == 1
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assert pow(2, 2) == 4
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assert pow(1, 2.0) == 1.0
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assert pow(2.0, 1) == 2.0
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assert pow(0, 10**1000) == 0
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assert pow(1, 10**1000) == 1
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assert pow(-1, 10**1000 + 1) == -1
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assert pow(-1, 10**1000) == 1
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assert pow(2, 4, 5) == 1
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assert_raises(TypeError, pow, 2, 4, 5.0)
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assert_raises(TypeError, pow, 2, 4.0, 5)
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assert_raises(TypeError, pow, 2.0, 4, 5)
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assert pow(2, -1, 5) == 3
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assert_raises(ValueError, pow, 2, 2, 0)
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assert_raises(OverflowError, pow, -2, 2000.5)
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assert_raises(OverflowError, pow, -2.0, 2000.5)
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assert_raises(OverflowError, complex(-2).__pow__, complex(2000.5))
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# float pow overflow (positive base or negative^integer) — finite inputs
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# producing a result outside f64 range must raise OverflowError, not silently
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# return inf.
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assert_raises(OverflowError, pow, 2.0, 2000)
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assert_raises(OverflowError, pow, 2.0, 2000.0)
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assert_raises(OverflowError, pow, 10.0, 400)
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assert_raises(OverflowError, pow, 1.5, 10000)
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assert_raises(OverflowError, pow, -2.0, 2000)
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assert_raises(OverflowError, pow, -2.0, 2001)
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assert_raises(OverflowError, pow, 1e150, 3)
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assert_raises(OverflowError, pow, 0.5, -2000)
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# Intentional infinities — when an input is already inf, the result inf is
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# expected and must NOT raise OverflowError.
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import math
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assert pow(math.inf, 2.0) == math.inf
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assert pow(2.0, math.inf) == math.inf
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assert pow(math.inf, math.inf) == math.inf
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# Underflow yields exact zero (not OverflowError).
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assert pow(2.0, -2000) == 0.0
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# pow(1.0, anything) == 1.0 — must not trigger overflow path.
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assert pow(1.0, 1e308) == 1.0
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# NaN propagates without raising.
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assert math.isnan(pow(math.nan, 2.0))
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assert math.isnan(pow(2.0, math.nan))
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assert_raises(TypeError, pow, 1, None, 0)
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assert_raises(TypeError, pow, True, 1.5, False)
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assert_almost_equal = assert_equal
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def powtest(type):
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if type != float:
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for i in range(-1000, 1000):
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assert_equal(pow(type(i), 0), 1)
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assert_equal(pow(type(i), 1), type(i))
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assert_equal(pow(type(0), 1), type(0))
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assert_equal(pow(type(1), 1), type(1))
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for i in range(-100, 100):
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assert_equal(pow(type(i), 3), i * i * i)
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pow2 = 1
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for i in range(0, 31):
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assert_equal(pow(2, i), pow2)
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if i != 30:
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pow2 = pow2 * 2
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for othertype in (int,):
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for i in list(range(-10, 0)) + list(range(1, 10)):
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ii = type(i)
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for j in range(1, 11):
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jj = -othertype(j)
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pow(ii, jj)
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for othertype in int, float:
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for i in range(1, 100):
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zero = type(0)
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exp = -othertype(i / 10.0)
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if exp == 0:
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continue
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assert_raises(ZeroDivisionError, pow, zero, exp)
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il, ih = -20, 20
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jl, jh = -5, 5
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kl, kh = -10, 10
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asseq = assert_equal
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if type == float:
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il = 1
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asseq = assert_almost_equal
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elif type == int:
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jl = 0
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elif type == int:
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jl, jh = 0, 15
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for i in range(il, ih + 1):
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for j in range(jl, jh + 1):
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for k in range(kl, kh + 1):
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if k != 0:
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if type == float or j < 0:
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assert_raises(TypeError, pow, type(i), j, k)
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continue
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asseq(pow(type(i), j, k), pow(type(i), j) % type(k))
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def test_powint():
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powtest(int)
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def test_powfloat():
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powtest(float)
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def test_other():
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# Other tests-- not very systematic
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assert_equal(pow(3, 3) % 8, pow(3, 3, 8))
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assert_equal(pow(3, 3) % -8, pow(3, 3, -8))
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assert_equal(pow(3, 2) % -2, pow(3, 2, -2))
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assert_equal(pow(-3, 3) % 8, pow(-3, 3, 8))
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assert_equal(pow(-3, 3) % -8, pow(-3, 3, -8))
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assert_equal(pow(5, 2) % -8, pow(5, 2, -8))
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assert_equal(pow(3, 3) % 8, pow(3, 3, 8))
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assert_equal(pow(3, 3) % -8, pow(3, 3, -8))
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assert_equal(pow(3, 2) % -2, pow(3, 2, -2))
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assert_equal(pow(-3, 3) % 8, pow(-3, 3, 8))
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assert_equal(pow(-3, 3) % -8, pow(-3, 3, -8))
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assert_equal(pow(5, 2) % -8, pow(5, 2, -8))
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for i in range(-10, 11):
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for j in range(0, 6):
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for k in range(-7, 11):
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if j >= 0 and k != 0:
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assert_equal(pow(i, j) % k, pow(i, j, k))
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if j >= 0 and k != 0:
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assert_equal(pow(int(i), j) % k, pow(int(i), j, k))
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def test_bug643260():
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class TestRpow:
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def __rpow__(self, other):
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return None
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None ** TestRpow() # Won't fail when __rpow__ invoked. SF bug #643260.
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def test_bug705231():
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# -1.0 raised to an integer should never blow up. It did if the
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# platform pow() was buggy, and Python didn't worm around it.
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eq = assert_equal
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a = -1.0
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# The next two tests can still fail if the platform floor()
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# function doesn't treat all large inputs as integers
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# test_math should also fail if that is happening
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eq(pow(a, 1.23e167), 1.0)
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eq(pow(a, -1.23e167), 1.0)
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for b in range(-10, 11):
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eq(pow(a, float(b)), b & 1 and -1.0 or 1.0)
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for n in range(0, 100):
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fiveto = float(5**n)
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# For small n, fiveto will be odd. Eventually we run out of
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# mantissa bits, though, and thereafer fiveto will be even.
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expected = fiveto % 2.0 and -1.0 or 1.0
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eq(pow(a, fiveto), expected)
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eq(pow(a, -fiveto), expected)
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eq(expected, 1.0) # else we didn't push fiveto to evenness
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tests = [f for name, f in locals().items() if name.startswith("test_")]
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for f in tests:
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f()
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