bart%videovax.tv.tek.com@RELAY.CS.NET (Bart Massey) (07/27/90)
I have a YACC-able grammar in front of me, of about 2000 lines, which I
wrote for a complicated assembly language with a bunch of magic
preprocessing. When I produce a parser for this grammar using either GNU
Bison or AT&T YACC, the resulting program fails to reject some inputs
containing simple syntax errors. I didn't even realize there was a problem
until I tried producing the parser using Corbett's "Berkeley YACC", at which
point the resulting program correctly rejected these incorrect inputs.
Please excuse the vagueness of the above, but I haven't been able to reduce
this hairy kludge of mine to a simple grammar/program which displays the
problem. My question is: under what known circumstances, if any, do both
Bison and YACC produce parsers which fail to reject incorrect programs?
Does BYACC fix any of these?
I hesitate to even ask such a vague question, but I thought I'd give it
a shot, since the underlying issue seems pretty critical to me -- I'm trusting
this parser to distinguish syntactically correct inputs from syntactically
incorrect ones...
Any comments or ideas, or should I just go crawl back under whatever rock
I crawled out from under? :-)
Bart Massey
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