srini@synopsys.Synopsys.COM (Srinivas Raghvendra) (03/05/91)
This is a question about the standard Yacc tool distributed with Unix.
I notice that Yacc uses a #define named YYMAXDEPTH and that this value has
been set at 150.
(1) I notice that even for moderately nested constructs, this seems
insufficient. (I get a Yacc stack overflow). Has anybody else faced
the same problem ?
(2) If the answer to (1) is Yes, what is a reasonable value for
YYMAXDEPTH ?
Srinivas Raghvendra, Synopsys, Inc., Mountain View, CA
(415)962-5000, srini@synopsys.com
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In article <694@synopsys.COM> srini@synopsys.Synopsys.COM (Srinivas Raghvendra) writes: >This is a question about the standard Yacc tool distributed with Unix. > >I notice that Yacc uses a #define named YYMAXDEPTH and that this value has >been set at 150. > (1) I notice that even for moderately nested constructs, this seems > insufficient. (I get a Yacc stack overflow). Has anybody else faced > the same problem ? > (2) If the answer to (1) is Yes, what is a reasonable value for > YYMAXDEPTH ? You may want to use the __RUNTIME_YYMAXDEPTH option, which allows runtime allocation of YACC stacks. You may choose a convenient value for the increment YYINCREMENT. This uses malloc (3) routines to manage stacks. Caveat: The version of yacc that I have (on HP-UX 7.0) demands char *malloc (), which may interfere with ANSI headers. Dipankar Gupta Hewlett-Packard India Software Operation, Bangalore, India dg@hplb.hpl.hp.com [This must be an HP-ism, it's not present in the SVR3 yacc parser. Personally, I've always found the default depth to be plenty. What sort of grammars are you parsing that overflow? -John] -- Send compilers articles to compilers@iecc.cambridge.ma.us or {ima | spdcc | world}!iecc!compilers. Meta-mail to compilers-request.
bliss@sp64.csrd.uiuc.edu (Brian Bliss) (03/09/91)
In article <694@synopsys.COM>, srini@synopsys.Synopsys.COM (Srinivas Raghvendra) writes: |> I notice that Yacc uses a #define named YYMAXDEPTH and that this value has |> been set at 150. |> (1) I notice that even for moderately nested constructs, this seems |> insufficient. (I get a Yacc stack overflow). If you get overflows, you are probably using too many right-recursive productions in you grammar. change these to left-recursive productions and the stack won't grow without bound. (i.e. lemme see your grammar). bb -- Send compilers articles to compilers@iecc.cambridge.ma.us or {ima | spdcc | world}!iecc!compilers. Meta-mail to compilers-request.
kathy@hpdcdb.fc.hp.com (Kathy Harris) (03/14/91)
dg@hpl.hp.com (Dipankar Gupta) writes: >You may want to use the __RUNTIME_YYMAXDEPTH option, which allows runtime This is an HP-UX feature, not part of standard (POSIX, ???) yacc. Kathy Harris Colorado Language Labratory Hewlett Packard Ft. Collins, Co. -- Send compilers articles to compilers@iecc.cambridge.ma.us or {ima | spdcc | world}!iecc!compilers. Meta-mail to compilers-request.