[Bug-openmcl] ASSOC bug

[Gary Byers]

On Sat, 10 Jul 2004, Chris Wright wrote:

> Hello,
>
> In OpenMCL version 0.14-031220, CCL::ASSEQL (as called by ASSOC)
> doesn't signal a TYPE-ERROR when given certain types of bad association
> lists.  I haven't kept up with the lastest CVS, so I don't know if this
> has been fixed already.
>
> Someshta:/Volumes/Tundra/Programming/lisp/ccl cwright$ ./dppccl
> Welcome to OpenMCL Version (Alpha: Darwin) 0.14-031220!
> ? (assoc 3 '(3))
> Unhandled exception 11 at 0x020a3e9c, context->regs at #xf0135738
> Read operation to unmapped address 0x0000000f
>  While executing: #<Function ASSEQL #x06076f36>
> ? for help
> [3598] OpenMCL kernel debugger: B

This was fixed in 0.14.1, and doesn't seem to have regressed in 0.14.2-p1
(the current version.)

>
> A quick look in the source makes me think that the use of CCL::%CAR on
> the list elements is the culprit, but a toplevel (CCL::%CAR 3) doesn't
> drop into the kernel debugger, and (ASSOC 3 '(foo)) returns NIL.
>

CCL::%CAR will only be unsafe (and a few cycles faster) in compiled code.
(You're right that it was used unsafely in ASSEQL and a few related places).

> Cheers,
>
> Chris Wright
>
>
>
>