On 3/15/10 10:45 AM, Helmut Eller wrote:
* Raymond Toy [2010-03-15 15:01+0100] writes:
On 3/12/10 11:45 AM, Helmut Eller wrote:
* Raymond Toy [2010-03-12 12:35+0100] writes:
So COMPILE has silently zapped the structure. We should probably print he warning for this too.
Yes, definitely. Also for this:
(defstruct xyz a) (setf (fdefinition 'xyz-a) (lambda () 42))
I added a hook to *setf-fdefinition-hook* to check for this case. Works ok, but now I can't compile clx/depdefs.lisp. CMUCL complains about redefining reply-size and buffer-lock which are slot accessor functions. But I haven't figured out from the code where the redefinition is coming from.
Also, consider this:
(defstruct abc a b c) (defun abc-a () 42)
CMUCL undefines the structure, but
CMUCL undefines the structure? That seems a bit aggressive. I think it should only delete the (c:info function info 'abc-a) entry if that's not done yet. The compiler uses that to recognize "known" functions.
The code that does this is define-function-name in proclaim.lisp. If the name is an accessor-for, then undefine-structure is called. The comment for undefine-structure says it's supposed to blow away all compiler info and undefining all associated functions.
I don't know if (setf abc-a) still works if the info entry for abc-a is cleared.
(defstruct abc a)
produces an error about incompatibly redefining the structure.
That seems totally OK to me.
Well, I was expecting that if we undefined the structure, then there would be no information about the structure, and hence didn't exist. But perhaps that can't be completely true if there are already structure objects of that type.
If we undefined the structure, I would expect make-xyz (or make-abc) not to work.
What to do?
I wouldn't undefine the entire structure; only redefine the named
That's the historical behavior, but I don't think I've ever run into this before, even when playing around. I only noticed this when looking at compile and define-function-name to see how things worked.
accessor function. For the printer we could come up with something like SLOT-VALUE but it should work without PCL.
There's probably some way to do this without PCL. Ray