Leaked source code of windows server 2003
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# Stackobj.pm
#
# Copyright (c) 1996 Malcolm Beattie
#
# You may distribute under the terms of either the GNU General Public
# License or the Artistic License, as specified in the README file.
#
package B::Stackobj;
use Exporter ();
@ISA = qw(Exporter);
@EXPORT_OK = qw(set_callback T_UNKNOWN T_DOUBLE T_INT VALID_UNSIGNED
VALID_INT VALID_DOUBLE VALID_SV REGISTER TEMPORARY);
%EXPORT_TAGS = (types => [qw(T_UNKNOWN T_DOUBLE T_INT)],
flags => [qw(VALID_INT VALID_DOUBLE VALID_SV
VALID_UNSIGNED REGISTER TEMPORARY)]);
use Carp qw(confess);
use strict;
use B qw(class SVf_IOK SVf_NOK SVf_IVisUV);
# Types
sub T_UNKNOWN () { 0 }
sub T_DOUBLE () { 1 }
sub T_INT () { 2 }
sub T_SPECIAL () { 3 }
# Flags
sub VALID_INT () { 0x01 }
sub VALID_UNSIGNED () { 0x02 }
sub VALID_DOUBLE () { 0x04 }
sub VALID_SV () { 0x08 }
sub REGISTER () { 0x10 } # no implicit write-back when calling subs
sub TEMPORARY () { 0x20 } # no implicit write-back needed at all
sub SAVE_INT () { 0x40 } #if int part needs to be saved at all
sub SAVE_DOUBLE () { 0x80 } #if double part needs to be saved at all
#
# Callback for runtime code generation
#
my $runtime_callback = sub { confess "set_callback not yet called" };
sub set_callback (&) { $runtime_callback = shift }
sub runtime { &$runtime_callback(@_) }
#
# Methods
#
sub write_back { confess "stack object does not implement write_back" }
sub invalidate { shift->{flags} &= ~(VALID_INT |VALID_UNSIGNED | VALID_DOUBLE) }
sub as_sv {
my $obj = shift;
if (!($obj->{flags} & VALID_SV)) {
$obj->write_back;
$obj->{flags} |= VALID_SV;
}
return $obj->{sv};
}
sub as_int {
my $obj = shift;
if (!($obj->{flags} & VALID_INT)) {
$obj->load_int;
$obj->{flags} |= VALID_INT|SAVE_INT;
}
return $obj->{iv};
}
sub as_double {
my $obj = shift;
if (!($obj->{flags} & VALID_DOUBLE)) {
$obj->load_double;
$obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE;
}
return $obj->{nv};
}
sub as_numeric {
my $obj = shift;
return $obj->{type} == T_INT ? $obj->as_int : $obj->as_double;
}
sub as_bool {
my $obj=shift;
if ($obj->{flags} & VALID_INT ){
return $obj->{iv};
}
if ($obj->{flags} & VALID_DOUBLE ){
return $obj->{nv};
}
return sprintf("(SvTRUE(%s))", $obj->as_sv) ;
}
#
# Debugging methods
#
sub peek {
my $obj = shift;
my $type = $obj->{type};
my $flags = $obj->{flags};
my @flags;
if ($type == T_UNKNOWN) {
$type = "T_UNKNOWN";
} elsif ($type == T_INT) {
$type = "T_INT";
} elsif ($type == T_DOUBLE) {
$type = "T_DOUBLE";
} else {
$type = "(illegal type $type)";
}
push(@flags, "VALID_INT") if $flags & VALID_INT;
push(@flags, "VALID_DOUBLE") if $flags & VALID_DOUBLE;
push(@flags, "VALID_SV") if $flags & VALID_SV;
push(@flags, "REGISTER") if $flags & REGISTER;
push(@flags, "TEMPORARY") if $flags & TEMPORARY;
@flags = ("none") unless @flags;
return sprintf("%s type=$type flags=%s sv=$obj->{sv}",
class($obj), join("|", @flags));
}
sub minipeek {
my $obj = shift;
my $type = $obj->{type};
my $flags = $obj->{flags};
if ($type == T_INT || $flags & VALID_INT) {
return $obj->{iv};
} elsif ($type == T_DOUBLE || $flags & VALID_DOUBLE) {
return $obj->{nv};
} else {
return $obj->{sv};
}
}
#
# Caller needs to ensure that set_int, set_double,
# set_numeric and set_sv are only invoked on legal lvalues.
#
sub set_int {
my ($obj, $expr,$unsigned) = @_;
runtime("$obj->{iv} = $expr;");
$obj->{flags} &= ~(VALID_SV | VALID_DOUBLE);
$obj->{flags} |= VALID_INT|SAVE_INT;
$obj->{flags} |= VALID_UNSIGNED if $unsigned;
}
sub set_double {
my ($obj, $expr) = @_;
runtime("$obj->{nv} = $expr;");
$obj->{flags} &= ~(VALID_SV | VALID_INT);
$obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE;
}
sub set_numeric {
my ($obj, $expr) = @_;
if ($obj->{type} == T_INT) {
$obj->set_int($expr);
} else {
$obj->set_double($expr);
}
}
sub set_sv {
my ($obj, $expr) = @_;
runtime("SvSetSV($obj->{sv}, $expr);");
$obj->invalidate;
$obj->{flags} |= VALID_SV;
}
#
# Stackobj::Padsv
#
@B::Stackobj::Padsv::ISA = 'B::Stackobj';
sub B::Stackobj::Padsv::new {
my ($class, $type, $extra_flags, $ix, $iname, $dname) = @_;
$extra_flags |= SAVE_INT if $extra_flags & VALID_INT;
$extra_flags |= SAVE_DOUBLE if $extra_flags & VALID_DOUBLE;
bless {
type => $type,
flags => VALID_SV | $extra_flags,
sv => "PL_curpad[$ix]",
iv => "$iname",
nv => "$dname"
}, $class;
}
sub B::Stackobj::Padsv::load_int {
my $obj = shift;
if ($obj->{flags} & VALID_DOUBLE) {
runtime("$obj->{iv} = $obj->{nv};");
} else {
runtime("$obj->{iv} = SvIV($obj->{sv});");
}
$obj->{flags} |= VALID_INT|SAVE_INT;
}
sub B::Stackobj::Padsv::load_double {
my $obj = shift;
$obj->write_back;
runtime("$obj->{nv} = SvNV($obj->{sv});");
$obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE;
}
sub B::Stackobj::Padsv::save_int {
my $obj = shift;
return $obj->{flags} & SAVE_INT;
}
sub B::Stackobj::Padsv::save_double {
my $obj = shift;
return $obj->{flags} & SAVE_DOUBLE;
}
sub B::Stackobj::Padsv::write_back {
my $obj = shift;
my $flags = $obj->{flags};
return if $flags & VALID_SV;
if ($flags & VALID_INT) {
if ($flags & VALID_UNSIGNED ){
runtime("sv_setuv($obj->{sv}, $obj->{iv});");
}else{
runtime("sv_setiv($obj->{sv}, $obj->{iv});");
}
} elsif ($flags & VALID_DOUBLE) {
runtime("sv_setnv($obj->{sv}, $obj->{nv});");
} else {
confess "write_back failed for lexical @{[$obj->peek]}\n";
}
$obj->{flags} |= VALID_SV;
}
#
# Stackobj::Const
#
@B::Stackobj::Const::ISA = 'B::Stackobj';
sub B::Stackobj::Const::new {
my ($class, $sv) = @_;
my $obj = bless {
flags => 0,
sv => $sv # holds the SV object until write_back happens
}, $class;
if ( ref($sv) eq "B::SPECIAL" ){
$obj->{type}= T_SPECIAL;
}else{
my $svflags = $sv->FLAGS;
if ($svflags & SVf_IOK) {
$obj->{flags} = VALID_INT|VALID_DOUBLE;
$obj->{type} = T_INT;
if ($svflags & SVf_IVisUV){
$obj->{flags} |= VALID_UNSIGNED;
$obj->{nv} = $obj->{iv} = $sv->UVX;
}else{
$obj->{nv} = $obj->{iv} = $sv->IV;
}
} elsif ($svflags & SVf_NOK) {
$obj->{flags} = VALID_INT|VALID_DOUBLE;
$obj->{type} = T_DOUBLE;
$obj->{iv} = $obj->{nv} = $sv->NV;
} else {
$obj->{type} = T_UNKNOWN;
}
}
return $obj;
}
sub B::Stackobj::Const::write_back {
my $obj = shift;
return if $obj->{flags} & VALID_SV;
# Save the SV object and replace $obj->{sv} by its C source code name
$obj->{sv} = $obj->{sv}->save;
$obj->{flags} |= VALID_SV|VALID_INT|VALID_DOUBLE;
}
sub B::Stackobj::Const::load_int {
my $obj = shift;
if (ref($obj->{sv}) eq "B::RV"){
$obj->{iv} = int($obj->{sv}->RV->PV);
}else{
$obj->{iv} = int($obj->{sv}->PV);
}
$obj->{flags} |= VALID_INT;
}
sub B::Stackobj::Const::load_double {
my $obj = shift;
if (ref($obj->{sv}) eq "B::RV"){
$obj->{nv} = $obj->{sv}->RV->PV + 0.0;
}else{
$obj->{nv} = $obj->{sv}->PV + 0.0;
}
$obj->{flags} |= VALID_DOUBLE;
}
sub B::Stackobj::Const::invalidate {}
#
# Stackobj::Bool
#
@B::Stackobj::Bool::ISA = 'B::Stackobj';
sub B::Stackobj::Bool::new {
my ($class, $preg) = @_;
my $obj = bless {
type => T_INT,
flags => VALID_INT|VALID_DOUBLE,
iv => $$preg,
nv => $$preg,
preg => $preg # this holds our ref to the pseudo-reg
}, $class;
return $obj;
}
sub B::Stackobj::Bool::write_back {
my $obj = shift;
return if $obj->{flags} & VALID_SV;
$obj->{sv} = "($obj->{iv} ? &PL_sv_yes : &PL_sv_no)";
$obj->{flags} |= VALID_SV;
}
# XXX Might want to handle as_double/set_double/load_double?
sub B::Stackobj::Bool::invalidate {}
1;
__END__
=head1 NAME
B::Stackobj - Helper module for CC backend
=head1 SYNOPSIS
use B::Stackobj;
=head1 DESCRIPTION
See F<ext/B/README>.
=head1 AUTHOR
Malcolm Beattie, C<[email protected]>
=cut