[Python-Dev] Re: [snake-farm] test test_slice failed -- [9, 7, 5, 3, 1] == [0] (original) (raw)

Neal Norwitz neal@metaslash.com
Tue, 05 Nov 2002 18:23:19 -0500

On Tue, Nov 05, 2002 at 10:38:18PM +0100, Anders Qvist wrote:

Between 1036491804 and 1036522446 (should be GMT 2002-11-05, 10:20 and 2002-11-05, 18:54 respectively), testslice started failing with the following message:

test testslice failed -- [9, 7, 5, 3, 1] == [0] om moghedien; linux/alpha. There has been some changes containing pointer arithmetic around line 160 of sliceobjects.c, which might be guilty (just a shot in the dark; 64-bit clean?):

It is a 64-bit problem, but doesn't have to do with the checkin to sliceobject. The new test (below) broke with old code too.

    vereq(range(10)[::sys.maxint - 1], [0])

The problem is that sizeof(int) != sizeof(long). The parameters for PySlice_GetIndices() and PySlice_GetIndicesEx() take ints, not longs. So the code is doing:

    range(10)[::-2]

since the high 32 bits are lost.

The only solution I can think of is to have 2 interfaces:

PySlice_GetIndicesEx() was added in 2.3.

Otherwise, we are stuck with slices only being able to support 32 bits even on 64 bit architectures.

Other ideas?

Neal