3 # Copyright (c) 1996 Malcolm Beattie
5 # You may distribute under the terms of either the GNU General Public
6 # License or the Artistic License, as specified in the README file.
11 @EXPORT_OK = qw(set_callback T_UNKNOWN T_DOUBLE T_INT
12 VALID_INT VALID_DOUBLE VALID_SV REGISTER TEMPORARY);
13 %EXPORT_TAGS = (types => [qw(T_UNKNOWN T_DOUBLE T_INT)],
14 flags => [qw(VALID_INT VALID_DOUBLE VALID_SV
15 REGISTER TEMPORARY)]);
19 use B qw(class SVf_IOK SVf_NOK);
22 sub T_UNKNOWN () { 0 }
25 sub T_SPECIAL () { 3 }
28 sub VALID_INT () { 0x01 }
29 sub VALID_DOUBLE () { 0x02 }
30 sub VALID_SV () { 0x04 }
31 sub REGISTER () { 0x08 } # no implicit write-back when calling subs
32 sub TEMPORARY () { 0x10 } # no implicit write-back needed at all
35 # Callback for runtime code generation
37 my $runtime_callback = sub { confess "set_callback not yet called" };
38 sub set_callback (&) { $runtime_callback = shift }
39 sub runtime { &$runtime_callback(@_) }
45 sub write_back { confess "stack object does not implement write_back" }
47 sub invalidate { shift->{flags} &= ~(VALID_INT | VALID_DOUBLE) }
51 if (!($obj->{flags} & VALID_SV)) {
53 $obj->{flags} |= VALID_SV;
60 if (!($obj->{flags} & VALID_INT)) {
62 $obj->{flags} |= VALID_INT;
69 if (!($obj->{flags} & VALID_DOUBLE)) {
71 $obj->{flags} |= VALID_DOUBLE;
78 return $obj->{type} == T_INT ? $obj->as_int : $obj->as_double;
83 if ($obj->{flags} & VALID_INT ){
86 if ($obj->{flags} & VALID_DOUBLE ){
89 return sprintf("(SvTRUE(%s))", $obj->as_sv) ;
97 my $type = $obj->{type};
98 my $flags = $obj->{flags};
100 if ($type == T_UNKNOWN) {
102 } elsif ($type == T_INT) {
104 } elsif ($type == T_DOUBLE) {
107 $type = "(illegal type $type)";
109 push(@flags, "VALID_INT") if $flags & VALID_INT;
110 push(@flags, "VALID_DOUBLE") if $flags & VALID_DOUBLE;
111 push(@flags, "VALID_SV") if $flags & VALID_SV;
112 push(@flags, "REGISTER") if $flags & REGISTER;
113 push(@flags, "TEMPORARY") if $flags & TEMPORARY;
114 @flags = ("none") unless @flags;
115 return sprintf("%s type=$type flags=%s sv=$obj->{sv}",
116 class($obj), join("|", @flags));
121 my $type = $obj->{type};
122 my $flags = $obj->{flags};
123 if ($type == T_INT || $flags & VALID_INT) {
125 } elsif ($type == T_DOUBLE || $flags & VALID_DOUBLE) {
133 # Caller needs to ensure that set_int, set_double,
134 # set_numeric and set_sv are only invoked on legal lvalues.
137 my ($obj, $expr) = @_;
138 runtime("$obj->{iv} = $expr;");
139 $obj->{flags} &= ~(VALID_SV | VALID_DOUBLE);
140 $obj->{flags} |= VALID_INT;
144 my ($obj, $expr) = @_;
145 runtime("$obj->{nv} = $expr;");
146 $obj->{flags} &= ~(VALID_SV | VALID_INT);
147 $obj->{flags} |= VALID_DOUBLE;
151 my ($obj, $expr) = @_;
152 if ($obj->{type} == T_INT) {
153 $obj->set_int($expr);
155 $obj->set_double($expr);
160 my ($obj, $expr) = @_;
161 runtime("SvSetSV($obj->{sv}, $expr);");
163 $obj->{flags} |= VALID_SV;
170 @B::Stackobj::Padsv::ISA = 'B::Stackobj';
171 sub B::Stackobj::Padsv::new {
172 my ($class, $type, $extra_flags, $ix, $iname, $dname) = @_;
175 flags => VALID_SV | $extra_flags,
176 sv => "PL_curpad[$ix]",
182 sub B::Stackobj::Padsv::load_int {
184 if ($obj->{flags} & VALID_DOUBLE) {
185 runtime("$obj->{iv} = $obj->{nv};");
187 runtime("$obj->{iv} = SvIV($obj->{sv});");
189 $obj->{flags} |= VALID_INT;
192 sub B::Stackobj::Padsv::load_double {
195 runtime("$obj->{nv} = SvNV($obj->{sv});");
196 $obj->{flags} |= VALID_DOUBLE;
199 sub B::Stackobj::Padsv::write_back {
201 my $flags = $obj->{flags};
202 return if $flags & VALID_SV;
203 if ($flags & VALID_INT) {
204 runtime("sv_setiv($obj->{sv}, $obj->{iv});");
205 } elsif ($flags & VALID_DOUBLE) {
206 runtime("sv_setnv($obj->{sv}, $obj->{nv});");
208 confess "write_back failed for lexical @{[$obj->peek]}\n";
210 $obj->{flags} |= VALID_SV;
217 @B::Stackobj::Const::ISA = 'B::Stackobj';
218 sub B::Stackobj::Const::new {
219 my ($class, $sv) = @_;
222 sv => $sv # holds the SV object until write_back happens
224 if ( ref($sv) eq "B::SPECIAL" ){
225 $obj->{type}= T_SPECIAL;
227 my $svflags = $sv->FLAGS;
228 if ($svflags & SVf_IOK) {
229 $obj->{flags} = VALID_INT|VALID_DOUBLE;
230 $obj->{type} = T_INT;
231 $obj->{nv} = $obj->{iv} = $sv->IV;
232 } elsif ($svflags & SVf_NOK) {
233 $obj->{flags} = VALID_INT|VALID_DOUBLE;
234 $obj->{type} = T_DOUBLE;
235 $obj->{iv} = $obj->{nv} = $sv->NV;
237 $obj->{type} = T_UNKNOWN;
243 sub B::Stackobj::Const::write_back {
245 return if $obj->{flags} & VALID_SV;
246 # Save the SV object and replace $obj->{sv} by its C source code name
247 $obj->{sv} = $obj->{sv}->save;
248 $obj->{flags} |= VALID_SV|VALID_INT|VALID_DOUBLE;
251 sub B::Stackobj::Const::load_int {
253 $obj->{iv} = int($obj->{sv}->PV);
254 $obj->{flags} |= VALID_INT;
257 sub B::Stackobj::Const::load_double {
259 $obj->{nv} = $obj->{sv}->PV + 0.0;
260 $obj->{flags} |= VALID_DOUBLE;
263 sub B::Stackobj::Const::invalidate {}
269 @B::Stackobj::Bool::ISA = 'B::Stackobj';
270 sub B::Stackobj::Bool::new {
271 my ($class, $preg) = @_;
274 flags => VALID_INT|VALID_DOUBLE,
277 preg => $preg # this holds our ref to the pseudo-reg
282 sub B::Stackobj::Bool::write_back {
284 return if $obj->{flags} & VALID_SV;
285 $obj->{sv} = "($obj->{iv} ? &PL_sv_yes : &PL_sv_no)";
286 $obj->{flags} |= VALID_SV;
289 # XXX Might want to handle as_double/set_double/load_double?
291 sub B::Stackobj::Bool::invalidate {}
299 B::Stackobj - Helper module for CC backend
311 Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>