wireshark/tools/pidl/expr.yp

# expr.yp
# Copyright (C) 2006 Jelmer Vernooij <jelmer@samba.org>
# Published under the GNU GPL
# 
%left	'->'
%right	'!' '~'
%left	'*' '/' '%'
%left	'+' '-'
%left	'<<' '>>'
%left	'>' '<'
%left	'==' '!='
%left	'&'
%left	'|'
%left	'&&'
%left	'||'
%left	'?' ':'
%left	NEG DEREF ADDROF INV
%left	'.'

%%
exp:
	NUM
	|
	TEXT                { "\"$_[1]\"" }
	|
	func
	|
	var
	|
	'~' exp %prec INV   { "~$_[2]" }
	|
	exp '+' exp         { "$_[1] + $_[3]" }
	|
	exp '-' exp         { "$_[1] - $_[3]" }
	|
	exp '*' exp         { "$_[1] * $_[3]" }
	|
	exp '%' exp         { "$_[1] % $_[3]" }
	|
	exp '<' exp         { "$_[1] < $_[3]" }
	|
	exp '>' exp         { "$_[1] > $_[3]" }
	|
	exp '|' exp         { "$_[1] | $_[3]" }
	|
	exp '==' exp        { "$_[1] == $_[3]" }
	|
	exp '<=' exp        { "$_[1] <= $_[3]" }
	|
	exp '=>' exp        { "$_[1] => $_[3]" }
	|
	exp '<<' exp        { "$_[1] << $_[3]" }
	|
	exp '>>' exp        { "$_[1] >> $_[3]" }
	|
	exp '!=' exp        { "$_[1] != $_[3]" }
	|
	exp '||' exp        { "$_[1] || $_[3]" }
	|
	exp '&&' exp        { "$_[1] && $_[3]" }
	|
	exp '&' exp         { "$_[1] & $_[3]" }
	|
	exp '?' exp ':' exp { "$_[1]?$_[3]:$_[5]" }
	|
	'~' exp             { "~$_[1]" }
	|
	'!' exp             { "not $_[1]" }
	|
	exp '/' exp         { "$_[1] / $_[3]" }
	|
	'-' exp %prec NEG   { "-$_[2]" }
	|
	'&' exp %prec ADDROF { "&$_[2]" }
	|
	exp '^' exp         { "$_[1]^$_[3]" }
	|
	'(' exp ')'         { "($_[2])" }
;

possible_pointer:
	VAR                              { $_[0]->_Lookup($_[1]) }
	|
	'*' possible_pointer %prec DEREF { $_[0]->_Dereference($_[2]); "*$_[2]" }
;

var:
	possible_pointer    { $_[0]->_Use($_[1]) }
	|
	var '.'	VAR         { $_[0]->_Use("$_[1].$_[3]") }
	|
	'(' var ')'         { "($_[2])" }
	|
	var '->' VAR        { $_[0]->_Use("*$_[1]"); $_[1]."->".$_[3] }
;


func:
	VAR '(' opt_args ')' { "$_[1]($_[3])" }
;

opt_args:
	#empty
	{ "" }
	|
	args
;

exp_or_possible_pointer:
	exp
	|
	possible_pointer
;

args:
	exp_or_possible_pointer
	|
	exp_or_possible_pointer ',' args { "$_[1], $_[3]" }
;

%%

package Parse::Pidl::Expr;

sub _Lexer {
	my($parser)=shift;

	$parser->YYData->{INPUT}=~s/^[ \t]//;

	for ($parser->YYData->{INPUT}) {
		if (s/^(0x[0-9A-Fa-f]+)//) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return('NUM',$1);
		}
		if (s/^([0-9]+(?:\.[0-9]+)?)//) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return('NUM',$1);
		}
		if (s/^([A-Za-z_][A-Za-z0-9_]*)//) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return('VAR',$1);
		}
		if (s/^\"(.*?)\"//) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return('TEXT',$1); 
		}
		if (s/^(==|!=|<=|>=|->|\|\||<<|>>|&&)//s) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return($1,$1);
		}
		if (s/^(.)//s) {
			$parser->YYData->{LAST_TOKEN} = $1;
			return($1,$1);
		}
	}
}

sub _Use($$)
{
	my ($self, $x) = @_;
	if (defined($self->YYData->{USE})) {
		return $self->YYData->{USE}->($x);
	}
	return $x;
}

sub _Lookup($$) 
{
	my ($self, $x) = @_;
	return $self->YYData->{LOOKUP}->($x);
}

sub _Dereference($$)
{
	my ($self, $x) = @_;
	if (defined($self->YYData->{DEREFERENCE})) {
		$self->YYData->{DEREFERENCE}->($x);
	}
}

sub _Error($)
{
	my ($self) = @_;
	if (defined($self->YYData->{LAST_TOKEN})) {
		$self->YYData->{ERROR}->("Parse error in `".$self->YYData->{FULL_INPUT}."' near `". $self->YYData->{LAST_TOKEN} . "'");
	} else {
		$self->YYData->{ERROR}->("Parse error in `".$self->YYData->{FULL_INPUT}."'");
	}
}

sub Run {
	my($self, $data, $error, $lookup, $deref, $use) = @_;

	$self->YYData->{FULL_INPUT} = $data;
	$self->YYData->{INPUT} = $data;
	$self->YYData->{LOOKUP} = $lookup;
	$self->YYData->{DEREFERENCE} = $deref;
	$self->YYData->{ERROR} = $error;
	$self->YYData->{USE} = $use;

	return $self->YYParse( yylex => \&_Lexer, yyerror => \&_Error);
}