| 1 | # Stackobj.pm |
| 2 | # |
| 3 | # Copyright (c) 1996 Malcolm Beattie |
| 4 | # |
| 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. |
| 7 | # |
| 8 | package B::Stackobj; |
| 9 | |
| 10 | our $VERSION = '1.00'; |
| 11 | |
| 12 | use Exporter (); |
| 13 | @ISA = qw(Exporter); |
| 14 | @EXPORT_OK = qw(set_callback T_UNKNOWN T_DOUBLE T_INT VALID_UNSIGNED |
| 15 | VALID_INT VALID_DOUBLE VALID_SV REGISTER TEMPORARY); |
| 16 | %EXPORT_TAGS = (types => [qw(T_UNKNOWN T_DOUBLE T_INT)], |
| 17 | flags => [qw(VALID_INT VALID_DOUBLE VALID_SV |
| 18 | VALID_UNSIGNED REGISTER TEMPORARY)]); |
| 19 | |
| 20 | use Carp qw(confess); |
| 21 | use strict; |
| 22 | use B qw(class SVf_IOK SVf_NOK SVf_IVisUV); |
| 23 | |
| 24 | # Types |
| 25 | sub T_UNKNOWN () { 0 } |
| 26 | sub T_DOUBLE () { 1 } |
| 27 | sub T_INT () { 2 } |
| 28 | sub T_SPECIAL () { 3 } |
| 29 | |
| 30 | # Flags |
| 31 | sub VALID_INT () { 0x01 } |
| 32 | sub VALID_UNSIGNED () { 0x02 } |
| 33 | sub VALID_DOUBLE () { 0x04 } |
| 34 | sub VALID_SV () { 0x08 } |
| 35 | sub REGISTER () { 0x10 } # no implicit write-back when calling subs |
| 36 | sub TEMPORARY () { 0x20 } # no implicit write-back needed at all |
| 37 | sub SAVE_INT () { 0x40 } #if int part needs to be saved at all |
| 38 | sub SAVE_DOUBLE () { 0x80 } #if double part needs to be saved at all |
| 39 | |
| 40 | |
| 41 | # |
| 42 | # Callback for runtime code generation |
| 43 | # |
| 44 | my $runtime_callback = sub { confess "set_callback not yet called" }; |
| 45 | sub set_callback (&) { $runtime_callback = shift } |
| 46 | sub runtime { &$runtime_callback(@_) } |
| 47 | |
| 48 | # |
| 49 | # Methods |
| 50 | # |
| 51 | |
| 52 | sub write_back { confess "stack object does not implement write_back" } |
| 53 | |
| 54 | sub invalidate { shift->{flags} &= ~(VALID_INT |VALID_UNSIGNED | VALID_DOUBLE) } |
| 55 | |
| 56 | sub as_sv { |
| 57 | my $obj = shift; |
| 58 | if (!($obj->{flags} & VALID_SV)) { |
| 59 | $obj->write_back; |
| 60 | $obj->{flags} |= VALID_SV; |
| 61 | } |
| 62 | return $obj->{sv}; |
| 63 | } |
| 64 | |
| 65 | sub as_int { |
| 66 | my $obj = shift; |
| 67 | if (!($obj->{flags} & VALID_INT)) { |
| 68 | $obj->load_int; |
| 69 | $obj->{flags} |= VALID_INT|SAVE_INT; |
| 70 | } |
| 71 | return $obj->{iv}; |
| 72 | } |
| 73 | |
| 74 | sub as_double { |
| 75 | my $obj = shift; |
| 76 | if (!($obj->{flags} & VALID_DOUBLE)) { |
| 77 | $obj->load_double; |
| 78 | $obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE; |
| 79 | } |
| 80 | return $obj->{nv}; |
| 81 | } |
| 82 | |
| 83 | sub as_numeric { |
| 84 | my $obj = shift; |
| 85 | return $obj->{type} == T_INT ? $obj->as_int : $obj->as_double; |
| 86 | } |
| 87 | |
| 88 | sub as_bool { |
| 89 | my $obj=shift; |
| 90 | if ($obj->{flags} & VALID_INT ){ |
| 91 | return $obj->{iv}; |
| 92 | } |
| 93 | if ($obj->{flags} & VALID_DOUBLE ){ |
| 94 | return $obj->{nv}; |
| 95 | } |
| 96 | return sprintf("(SvTRUE(%s))", $obj->as_sv) ; |
| 97 | } |
| 98 | |
| 99 | # |
| 100 | # Debugging methods |
| 101 | # |
| 102 | sub peek { |
| 103 | my $obj = shift; |
| 104 | my $type = $obj->{type}; |
| 105 | my $flags = $obj->{flags}; |
| 106 | my @flags; |
| 107 | if ($type == T_UNKNOWN) { |
| 108 | $type = "T_UNKNOWN"; |
| 109 | } elsif ($type == T_INT) { |
| 110 | $type = "T_INT"; |
| 111 | } elsif ($type == T_DOUBLE) { |
| 112 | $type = "T_DOUBLE"; |
| 113 | } else { |
| 114 | $type = "(illegal type $type)"; |
| 115 | } |
| 116 | push(@flags, "VALID_INT") if $flags & VALID_INT; |
| 117 | push(@flags, "VALID_DOUBLE") if $flags & VALID_DOUBLE; |
| 118 | push(@flags, "VALID_SV") if $flags & VALID_SV; |
| 119 | push(@flags, "REGISTER") if $flags & REGISTER; |
| 120 | push(@flags, "TEMPORARY") if $flags & TEMPORARY; |
| 121 | @flags = ("none") unless @flags; |
| 122 | return sprintf("%s type=$type flags=%s sv=$obj->{sv}", |
| 123 | class($obj), join("|", @flags)); |
| 124 | } |
| 125 | |
| 126 | sub minipeek { |
| 127 | my $obj = shift; |
| 128 | my $type = $obj->{type}; |
| 129 | my $flags = $obj->{flags}; |
| 130 | if ($type == T_INT || $flags & VALID_INT) { |
| 131 | return $obj->{iv}; |
| 132 | } elsif ($type == T_DOUBLE || $flags & VALID_DOUBLE) { |
| 133 | return $obj->{nv}; |
| 134 | } else { |
| 135 | return $obj->{sv}; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | # |
| 140 | # Caller needs to ensure that set_int, set_double, |
| 141 | # set_numeric and set_sv are only invoked on legal lvalues. |
| 142 | # |
| 143 | sub set_int { |
| 144 | my ($obj, $expr,$unsigned) = @_; |
| 145 | runtime("$obj->{iv} = $expr;"); |
| 146 | $obj->{flags} &= ~(VALID_SV | VALID_DOUBLE); |
| 147 | $obj->{flags} |= VALID_INT|SAVE_INT; |
| 148 | $obj->{flags} |= VALID_UNSIGNED if $unsigned; |
| 149 | } |
| 150 | |
| 151 | sub set_double { |
| 152 | my ($obj, $expr) = @_; |
| 153 | runtime("$obj->{nv} = $expr;"); |
| 154 | $obj->{flags} &= ~(VALID_SV | VALID_INT); |
| 155 | $obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE; |
| 156 | } |
| 157 | |
| 158 | sub set_numeric { |
| 159 | my ($obj, $expr) = @_; |
| 160 | if ($obj->{type} == T_INT) { |
| 161 | $obj->set_int($expr); |
| 162 | } else { |
| 163 | $obj->set_double($expr); |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | sub set_sv { |
| 168 | my ($obj, $expr) = @_; |
| 169 | runtime("SvSetSV($obj->{sv}, $expr);"); |
| 170 | $obj->invalidate; |
| 171 | $obj->{flags} |= VALID_SV; |
| 172 | } |
| 173 | |
| 174 | # |
| 175 | # Stackobj::Padsv |
| 176 | # |
| 177 | |
| 178 | @B::Stackobj::Padsv::ISA = 'B::Stackobj'; |
| 179 | sub B::Stackobj::Padsv::new { |
| 180 | my ($class, $type, $extra_flags, $ix, $iname, $dname) = @_; |
| 181 | $extra_flags |= SAVE_INT if $extra_flags & VALID_INT; |
| 182 | $extra_flags |= SAVE_DOUBLE if $extra_flags & VALID_DOUBLE; |
| 183 | bless { |
| 184 | type => $type, |
| 185 | flags => VALID_SV | $extra_flags, |
| 186 | sv => "PL_curpad[$ix]", |
| 187 | iv => "$iname", |
| 188 | nv => "$dname" |
| 189 | }, $class; |
| 190 | } |
| 191 | |
| 192 | sub B::Stackobj::Padsv::load_int { |
| 193 | my $obj = shift; |
| 194 | if ($obj->{flags} & VALID_DOUBLE) { |
| 195 | runtime("$obj->{iv} = $obj->{nv};"); |
| 196 | } else { |
| 197 | runtime("$obj->{iv} = SvIV($obj->{sv});"); |
| 198 | } |
| 199 | $obj->{flags} |= VALID_INT|SAVE_INT; |
| 200 | } |
| 201 | |
| 202 | sub B::Stackobj::Padsv::load_double { |
| 203 | my $obj = shift; |
| 204 | $obj->write_back; |
| 205 | runtime("$obj->{nv} = SvNV($obj->{sv});"); |
| 206 | $obj->{flags} |= VALID_DOUBLE|SAVE_DOUBLE; |
| 207 | } |
| 208 | sub B::Stackobj::Padsv::save_int { |
| 209 | my $obj = shift; |
| 210 | return $obj->{flags} & SAVE_INT; |
| 211 | } |
| 212 | |
| 213 | sub B::Stackobj::Padsv::save_double { |
| 214 | my $obj = shift; |
| 215 | return $obj->{flags} & SAVE_DOUBLE; |
| 216 | } |
| 217 | |
| 218 | sub B::Stackobj::Padsv::write_back { |
| 219 | my $obj = shift; |
| 220 | my $flags = $obj->{flags}; |
| 221 | return if $flags & VALID_SV; |
| 222 | if ($flags & VALID_INT) { |
| 223 | if ($flags & VALID_UNSIGNED ){ |
| 224 | runtime("sv_setuv($obj->{sv}, $obj->{iv});"); |
| 225 | }else{ |
| 226 | runtime("sv_setiv($obj->{sv}, $obj->{iv});"); |
| 227 | } |
| 228 | } elsif ($flags & VALID_DOUBLE) { |
| 229 | runtime("sv_setnv($obj->{sv}, $obj->{nv});"); |
| 230 | } else { |
| 231 | confess "write_back failed for lexical @{[$obj->peek]}\n"; |
| 232 | } |
| 233 | $obj->{flags} |= VALID_SV; |
| 234 | } |
| 235 | |
| 236 | # |
| 237 | # Stackobj::Const |
| 238 | # |
| 239 | |
| 240 | @B::Stackobj::Const::ISA = 'B::Stackobj'; |
| 241 | sub B::Stackobj::Const::new { |
| 242 | my ($class, $sv) = @_; |
| 243 | my $obj = bless { |
| 244 | flags => 0, |
| 245 | sv => $sv # holds the SV object until write_back happens |
| 246 | }, $class; |
| 247 | if ( ref($sv) eq "B::SPECIAL" ){ |
| 248 | $obj->{type}= T_SPECIAL; |
| 249 | }else{ |
| 250 | my $svflags = $sv->FLAGS; |
| 251 | if ($svflags & SVf_IOK) { |
| 252 | $obj->{flags} = VALID_INT|VALID_DOUBLE; |
| 253 | $obj->{type} = T_INT; |
| 254 | if ($svflags & SVf_IVisUV){ |
| 255 | $obj->{flags} |= VALID_UNSIGNED; |
| 256 | $obj->{nv} = $obj->{iv} = $sv->UVX; |
| 257 | }else{ |
| 258 | $obj->{nv} = $obj->{iv} = $sv->IV; |
| 259 | } |
| 260 | } elsif ($svflags & SVf_NOK) { |
| 261 | $obj->{flags} = VALID_INT|VALID_DOUBLE; |
| 262 | $obj->{type} = T_DOUBLE; |
| 263 | $obj->{iv} = $obj->{nv} = $sv->NV; |
| 264 | } else { |
| 265 | $obj->{type} = T_UNKNOWN; |
| 266 | } |
| 267 | } |
| 268 | return $obj; |
| 269 | } |
| 270 | |
| 271 | sub B::Stackobj::Const::write_back { |
| 272 | my $obj = shift; |
| 273 | return if $obj->{flags} & VALID_SV; |
| 274 | # Save the SV object and replace $obj->{sv} by its C source code name |
| 275 | $obj->{sv} = $obj->{sv}->save; |
| 276 | $obj->{flags} |= VALID_SV|VALID_INT|VALID_DOUBLE; |
| 277 | } |
| 278 | |
| 279 | sub B::Stackobj::Const::load_int { |
| 280 | my $obj = shift; |
| 281 | if (ref($obj->{sv}) eq "B::RV"){ |
| 282 | $obj->{iv} = int($obj->{sv}->RV->PV); |
| 283 | }else{ |
| 284 | $obj->{iv} = int($obj->{sv}->PV); |
| 285 | } |
| 286 | $obj->{flags} |= VALID_INT; |
| 287 | } |
| 288 | |
| 289 | sub B::Stackobj::Const::load_double { |
| 290 | my $obj = shift; |
| 291 | if (ref($obj->{sv}) eq "B::RV"){ |
| 292 | $obj->{nv} = $obj->{sv}->RV->PV + 0.0; |
| 293 | }else{ |
| 294 | $obj->{nv} = $obj->{sv}->PV + 0.0; |
| 295 | } |
| 296 | $obj->{flags} |= VALID_DOUBLE; |
| 297 | } |
| 298 | |
| 299 | sub B::Stackobj::Const::invalidate {} |
| 300 | |
| 301 | # |
| 302 | # Stackobj::Bool |
| 303 | # |
| 304 | |
| 305 | @B::Stackobj::Bool::ISA = 'B::Stackobj'; |
| 306 | sub B::Stackobj::Bool::new { |
| 307 | my ($class, $preg) = @_; |
| 308 | my $obj = bless { |
| 309 | type => T_INT, |
| 310 | flags => VALID_INT|VALID_DOUBLE, |
| 311 | iv => $$preg, |
| 312 | nv => $$preg, |
| 313 | preg => $preg # this holds our ref to the pseudo-reg |
| 314 | }, $class; |
| 315 | return $obj; |
| 316 | } |
| 317 | |
| 318 | sub B::Stackobj::Bool::write_back { |
| 319 | my $obj = shift; |
| 320 | return if $obj->{flags} & VALID_SV; |
| 321 | $obj->{sv} = "($obj->{iv} ? &PL_sv_yes : &PL_sv_no)"; |
| 322 | $obj->{flags} |= VALID_SV; |
| 323 | } |
| 324 | |
| 325 | # XXX Might want to handle as_double/set_double/load_double? |
| 326 | |
| 327 | sub B::Stackobj::Bool::invalidate {} |
| 328 | |
| 329 | 1; |
| 330 | |
| 331 | __END__ |
| 332 | |
| 333 | =head1 NAME |
| 334 | |
| 335 | B::Stackobj - Helper module for CC backend |
| 336 | |
| 337 | =head1 SYNOPSIS |
| 338 | |
| 339 | use B::Stackobj; |
| 340 | |
| 341 | =head1 DESCRIPTION |
| 342 | |
| 343 | See F<ext/B/README>. |
| 344 | |
| 345 | =head1 AUTHOR |
| 346 | |
| 347 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
| 348 | |
| 349 | =cut |