[antlr-interest] How do I fix "code too large" errors?

[Andrew Lentvorski]

Andrew Lentvorski wrote:
> Yes, I know that this is a Java error, but one does not need a huge 
> grammar to hit this.

Here's the grammar that causes the problem.  I put comments at the
FREETEXT lines which create the overflow in the lexer.

Any advice would be appreciated.

Thanks,
-a


grammar vcdfile2;

@lexer::members {
    boolean flgSimCommand = false;
    boolean flgFreeText = false;
    boolean flgNWSFreeText = false;
}

vcd	:	(declaration_command WS*)+ (simulation_command WS*)+ EOF;

simulation_command:	dumpvars_scmd | dumpoff_scmd | dumpon_scmd | SIMTIME | value_change;

value_change:	(VECTORT WS+ NWSFREETEXT) | (SCALART NWSFREETEXT);

dumpvars_scmd:	DUMPVARSK value_change+ ENDK;
dumpoff_scmd:	DUMPOFFK value_change+ ENDK;
dumpon_scmd:	DUMPONK value_change+ ENDK;

DUMPVARSK:	'$dumpvars';
DUMPOFFK:	'$dumpoff';
DUMPONK:	'$dumpon';

SIMTIME:	{flgSimCommand}?=> '#' ('0'..'9')+;
VECTORT:	{flgSimCommand}?=> 'b' ('0' | '1' | 'x' | 'X' | 'z' | 'Z')+ {flgNWSFreeText = true;};
SCALART:	{flgSimCommand}?=> ('0' | '1' | 'x' | 'X' | 'z' | 'Z') {flgNWSFreeText = true;};

declaration_command:	comment_dcmd | date_dcmd | enddef_dcmd | scope_dcmd | upscope_dcmd | var_dcmd | version_dcmd | timescale_dcmd ;

comment_dcmd:	COMMENTK FREETEXT ENDK;
date_dcmd:	DATEK FREETEXT ENDK;
enddef_dcmd:	ENDDEFK WS* ENDK;
scope_dcmd:	SCOPEK FREETEXT ENDK;
timescale_dcmd:	TIMESCALEK FREETEXT ENDK;
upscope_dcmd:	UPSCOPEK WS* ENDK;
var_dcmd:	VARK FREETEXT ENDK;
version_dcmd:	VERSIONK FREETEXT ENDK;
	

COMMENTK:	'$comment' {flgFreeText = true;};

DATEK	:	'$date' {flgFreeText = true;};
ENDDEFK	:	'$enddefinitions' {flgSimCommand = true;};
SCOPEK	:	'$scope' {flgFreeText = true;};
TIMESCALEK:	'$timescale' {flgFreeText = true;};
UPSCOPEK:	'$upscope';
VARK	:	'$var' {flgFreeText = true;};
VERSIONK:	'$version' {flgFreeText = true;};

ENDK	:	'$end';

/* The uncommented FREETEXT line below causes the lexer to blow through its limits */
FREETEXT:	{flgFreeText}?=> ( { ! (input.LA(1) == '$' && input.LA(2) == 'e' && input.LA(3) == 'n' && input.LA(4) == 'd') }?=> .)+;
/* This commented FREETEXT line below, however, does not hit the limits */
//FREETEXT:	{flgFreeText}?=> (~'$')+ {flgFreeText = false;};

NWSFREETEXT:	{flgNWSFreeText}?=> (~WS)+ {flgNWSFreeText=false;};

WS	:	(' '|'\n'|'\r'|'\t') ;
ANY	:	.;