[antlr-interest] Strange "code too large" error since *very simple* gated semantic predicates
loic.lefevre at bnpparibas.com
loic.lefevre at bnpparibas.com
Tue Dec 15 09:56:08 PST 2009
Hello,
I'm encountering a strange antlr issue. I get a "code too large" error
from the java compiler
on the DFA method specialStateTransition for the following grammar rule:
block_4_tags
: {"103".equals(messageType)}?=> block_4_mt103_tags
| {"202".equals(messageType)}?=> block_4_mt202_tags
;
The generated method has a switch with 339 labels.
Example of generated code:
public int specialStateTransition(int s, IntStream _input) throws
NoViableAltException {
TokenStream input = (TokenStream)_input;
int _s = s;
switch ( s ) {
case 0 :
int LA4_238 = input.LA(1);
int index4_238 = input.index();
input.rewind();
s = -1;
if ( (LA4_238==CAPITAL_LETTER) &&
(("202".equals(messageType)))) {s = 278;}
else if ( (LA4_238==DIGIT) &&
(("202".equals(messageType)))) {s = 279;}
input.seek(index4_238);
if ( s>=0 ) return s;
break;
case 1 :
int LA4_321 = input.LA(1);
int index4_321 = input.index();
input.rewind();
s = -1;
if ( (LA4_321==DIGIT) &&
(("202".equals(messageType)))) {s = 342;}
else if ( (LA4_321==LETTER) &&
(("202".equals(messageType)))) {s = 312;}
else if ( (LA4_321==CAPITAL_LETTER) &&
(("202".equals(messageType)))) {s = 313;}
else if ( (LA4_321==SLASH) &&
(("202".equals(messageType)))) {s = 314;}
else if ( (LA4_321==SPACE) &&
(("202".equals(messageType)))) {s = 315;}
else if ( (LA4_321==ANTI_SLASH) &&
(("202".equals(messageType)))) {s = 316;}
else if ( (LA4_321==MINUS) &&
(("202".equals(messageType)))) {s = 317;}
else if ( (LA4_321==COLON) &&
(("202".equals(messageType)))) {s = 318;}
else if ( (LA4_321==LPAREN) &&
(("202".equals(messageType)))) {s = 319;}
else if ( (LA4_321==RPAREN) &&
(("202".equals(messageType)))) {s = 320;}
else if ( (LA4_321==DOT) &&
(("202".equals(messageType)))) {s = 321;}
else if ( (LA4_321==COMMA) &&
(("202".equals(messageType)))) {s = 322;}
else if ( (LA4_321==PLUS) &&
(("202".equals(messageType)))) {s = 323;}
else if ( (LA4_321==QUOTE) &&
(("202".equals(messageType)))) {s = 324;}
else if ( (LA4_321==QUESTION_MARK) &&
(("202".equals(messageType)))) {s = 325;}
input.seek(index4_321);
if ( s>=0 ) return s;
break;
...
As you can see the gated semantic predicates are propagated to almost
every Java statements!
And this is *very* strange since the calling code is:
public final void block_4_tags() throws RecognitionException {
int block_4_tags_StartIndex = input.index();
try {
if ( state.backtracking>0 && alreadyParsedRule(input, 12) ) {
return ; }
// SWIFTMT.g:153:9: ({...}? => block_4_mt103_tags | {...}? =>
block_4_mt202_tags )
int alt4=2;
alt4 = dfa4.predict(input);
switch (alt4) {
case 1 :
// SWIFTMT.g:153:11: {...}? => block_4_mt103_tags
{
if ( !(("103".equals(messageType))) ) {
if (state.backtracking>0) {state.failed=true;
return ;}
throw new FailedPredicateException(input,
"block_4_tags", "\"103\".equals(messageType)");
}
if ( state.backtracking==0 ) {
System.out.println("Tags for MT103 chosen!");
}
pushFollow(FOLLOW_block_4_mt103_tags_in_block_4_tags809);
block_4_mt103_tags();
state._fsp--;
if (state.failed) return ;
}
break;
case 2 :
// SWIFTMT.g:154:11: {...}? => block_4_mt202_tags
{
if ( !(("202".equals(messageType))) ) {
if (state.backtracking>0) {state.failed=true;
return ;}
throw new FailedPredicateException(input,
"block_4_tags", "\"202\".equals(messageType)");
}
pushFollow(FOLLOW_block_4_mt202_tags_in_block_4_tags824);
block_4_mt202_tags();
state._fsp--;
if (state.failed) return ;
}
break;
}
}
catch (RecognitionException re) {
reportError(re);
recover(input,re);
}
finally {
if ( state.backtracking>0 ) { memoize(input, 12,
block_4_tags_StartIndex); }
}
return ;
}
I would rather expect something like:
if( "103".equals(messageType) ) {
pushFollow(FOLLOW_block_4_mt103_tags_in_block_4_tags809);
block_4_mt103_tags();
state._fsp--;
if (state.failed) return ;
} else
if( "202".equals(messageType) ) {
pushFollow(FOLLOW_block_4_mt202_tags_in_block_4_tags824);
block_4_mt202_tags();
state._fsp--;
if (state.failed) return ;
} else { /* error check? */ }
and of course this DFA4 would never exist :o)
Is it currently possible?
Has anyone some workaround?
I'll also try int comparison (I'm lucky since these are numbers) but I've
got more message types to test (290+).
Regards,
Loïc
This message and any attachments (the "message") is
intended solely for the addressees and is confidential.
If you receive this message in error, please delete it and
immediately notify the sender. Any use not in accord with
its purpose, any dissemination or disclosure, either whole
or partial, is prohibited except formal approval. The internet
can not guarantee the integrity of this message.
BNP PARIBAS (and its subsidiaries) shall (will) not
therefore be liable for the message if modified.
Do not print this message unless it is necessary,
consider the environment.
---------------------------------------------
Ce message et toutes les pieces jointes (ci-apres le
"message") sont etablis a l'intention exclusive de ses
destinataires et sont confidentiels. Si vous recevez ce
message par erreur, merci de le detruire et d'en avertir
immediatement l'expediteur. Toute utilisation de ce
message non conforme a sa destination, toute diffusion
ou toute publication, totale ou partielle, est interdite, sauf
autorisation expresse. L'internet ne permettant pas
d'assurer l'integrite de ce message, BNP PARIBAS (et ses
filiales) decline(nt) toute responsabilite au titre de ce
message, dans l'hypothese ou il aurait ete modifie.
N'imprimez ce message que si necessaire,
pensez a l'environnement.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.antlr.org/pipermail/antlr-interest/attachments/20091215/f58a8e92/attachment.html
More information about the antlr-interest
mailing list