[antlr-interest] java.lang.OutOfMemoryError: Java heap space
win at wincent.com
Tue Jun 5 11:18:39 PDT 2007
I'm trying to develop a parser for wiki markup and part of that
requires the recognition of URI tokens according to RFC 3986 (<http://
www.ietf.org/rfc/rfc3986.txt>). The internal structure of the URI
isn't of any interest to me, I just want to get a token for each URI,
so I'm doing all this in the lexer.
For testing purposes, I'm doing this first in a separate grammar,
which you can see here:
Basically this is the grammar from the RFC, but converted from the
ABNF used in that document (the ABNF is itself described in <http://
www.ietf.org/rfc/rfc2234.txt>) to use ANTLR's EBNF notation, and then
with some minor tweaks to eliminate ANTLRWorks warnings about
ambiguity or analysis problems. As far as I can tell, however, the
grammar matches the description in the RFC.
When I try to pipe this through ANTLR (v3 final) I get this:
Exception in thread "main" java.lang.OutOfMemoryError: Java heap
I tried cranking up the heap size, 256 MB, 512 MB, 768 MB and so on...
java -Xms32m -Xmx2048m org.antlr.Tool RFC3986.g
But to no avail... I got up to almost a gig and a half before swap
start thrashing itself to death and I had to kill the ANTLR process.
The funny thing is the grammar check works fine in ANTLRWorks (no
warnings printed to the console), it has no problems showing me
syntax diagrams, producing rule dependency graphs, or handling input
that I pass in via the interpreter.
I tried this with both C and Java as the target language, so the
problem seems to be language independent. From what I've read on this
list I guess the cause is something nasty in my grammar that I'll
need to work around. The trouble is, I don't even know where to begin
to look. Can anybody provide some pointers?
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