Commit | Line | Data |
---|---|---|
920dae64 AT |
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 |