On Fri, Dec 9, 2011 at 4:04 PM, James Wright james@chumsley.org wrote:
Hi,
I have encountered the following problem a couple of times before, although not as reproducibly as the memory corruption issue from my previous message: If I use the #m reader macro in a function somewhere, dump an SBCL core image, load the image, and call the function, I get memory corruption. I have mostly dealt with it up until now by not using the #m() notation in anything that I plan to dump to a binary.
This is odd. There is a make-load-form for foreign-arrays, so I assumed this would work. Example?
I believe that the cause is that the #m macro returns a foreign-array object directly (when foreign-array is the default grid type). If it returned a `make-grid' form instead, it would operate identically on e.g. the REPL. It would have the advantage, however, of being usable in a dumped image, since the array would be created at run-time instead of at read-time, and hence no foreign-pointers would be saved into the image.
My intent is that it be analogous to #, e.g. #(1.0d0 2.0d0) expands to a (CL) array. I used to have it the way you want but I changed it as of 3e610bd4d5261 to be analogous to the regular array macro (in fact, #m should make a CL array if grid:*default-grid-type* is set accordingly; I'm still not sure about the wisdom of doing that). I had a good reason for changing it, but I can't recall exactly what it was. Something was not working right is all I recall.
By the way, do you know about grid:grid? Maybe that's what you want. It's a function, so it evaluates its arguments (grid:grid pi pi pi) #m(3.141592653589793d0 3.141592653589793d0 3.141592653589793d0)
I've attached a patch that changes the #m reader macro to return a creation form instead of a literal. I hope you'll consider adding it. I've pasted a repl session below that demonstrates the difference.
Thanks,
James
I think I'd like to figure out why #m can't be saved before I consider changing this back.
Liam