bd556b6996
There were two issues with the existing code: 1. "1 << i" is computed as a 32-bit number so would overflow when executed on 64-bit machines (when mp_uint_t is 64-bit). This meant that *args beyond 32 positions would not be handled correctly. 2. star_args must fit as a positive small int so that it is encoded correctly in the emitted code. MP_SMALL_INT_BITS is too big because it overflows a small int by 1 bit. MP_SMALL_INT_BITS - 1 does not work because it produces a signed small int which is then sign extended when extracted (even by mp_obj_get_int_truncated), and this sign extension means that any position arg after *args is also treated as a star-arg. So the maximum bit position is MP_SMALL_INT_BITS - 2. This means that MP_OBJ_SMALL_INT_VALUE() can be used instead of mp_obj_get_int_truncated() to get the value of star_args. These issues are fixed by this commit, and a test added. Signed-off-by: Damien George <damien@micropython.org>
37 lines
930 B
Python
37 lines
930 B
Python
# Test the limit of the number of arguments to a function call.
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# This currently tests the case of *args after many positional args.
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def f(*args):
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return len(args)
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def test(n):
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pos_args = ",".join(str(i) for i in range(n))
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s = "f({}, *(100, 101), 102, 103)".format(pos_args)
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try:
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return eval(s)
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except SyntaxError:
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return "SyntaxError"
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# If the port has at least 32-bits then this test should pass.
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print(test(29))
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# This test should fail on all ports (overflows a small int).
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print(test(70))
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# Check that there is a correct transition to the limit of too many args before *args.
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reached_limit = False
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for i in range(30, 70):
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result = test(i)
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if reached_limit:
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if result != "SyntaxError":
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print("FAIL")
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else:
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if result == "SyntaxError":
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reached_limit = True
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else:
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if result != i + 4:
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print("FAIL")
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