On Sat, 2008-01-19 at 16:12 -0600, Patrick R. Michaud wrote: > On Fri, Jan 18, 2008 at 09:41:01PM -0800, Geoffrey Broadwell wrote: > > "Null PMC access in invoke(); misspelled sub name in function call?" > > I fear this error message may actually send a beginner down a false > trail. This particular error occurs anytime we attempt to call > a sub that cannot be located in the current lexical/namespace/global > symbol table. So, there could be other causes for the error besides > a simple misspelling.
Fair enough. I had indeed experienced the error both in the direct code I presented in the initial ticket, and in the case of a symbol table lookup. But no matter what route I took to get there, there were only two mistakes I had made: either I had misspelled the name somewhere, or I hadn't inserted it into the symbol table before looking it up (which itself had a few different causes -- one time it even turned out to be saving one file but not another in my editor). > The "Null PMC access in invoke()" except gets thrown at the > point of the invokecc call, at which point we no longer have > convenient access to the name. Nodnod, understood. > So, the options I see at this point are to modify the find_name > opcode to throw an exception when asked to locate a non-existent > symbol (note that this is somewhat counter to the way we've been > heading), or to have the PIR compiler generate code to check > the result of find_name and throw an exception. I personally don't want any runtime cost to improve this error message; I was merely suggesting the first thing that came to mind to demystify the original message. Heck, we can put a whole paragraph in the error message if need be, but *no runtime cost for correct code* please. I'd rather have a bad error message than a slower VM. -'f
