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1 | # CC.pm |
2 | # |
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3 | # Copyright (c) 1996, 1997, 1998 Malcolm Beattie |
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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::CC; |
9 | use strict; |
10 | use B qw(main_start main_root class comppadlist peekop svref_2object |
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11 | timing_info init_av); |
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12 | use B::C qw(save_unused_subs objsym init_sections mark_unused |
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13 | output_all output_boilerplate output_main); |
14 | use B::Bblock qw(find_leaders); |
15 | use B::Stackobj qw(:types :flags); |
16 | |
17 | # These should probably be elsewhere |
18 | # Flags for $op->flags |
19 | sub OPf_LIST () { 1 } |
20 | sub OPf_KNOW () { 2 } |
21 | sub OPf_MOD () { 32 } |
22 | sub OPf_STACKED () { 64 } |
23 | sub OPf_SPECIAL () { 128 } |
24 | # op-specific flags for $op->private |
25 | sub OPpASSIGN_BACKWARDS () { 64 } |
26 | sub OPpLVAL_INTRO () { 128 } |
27 | sub OPpDEREF_AV () { 32 } |
28 | sub OPpDEREF_HV () { 64 } |
29 | sub OPpDEREF () { OPpDEREF_AV|OPpDEREF_HV } |
30 | sub OPpFLIP_LINENUM () { 64 } |
31 | sub G_ARRAY () { 1 } |
32 | # cop.h |
33 | sub CXt_NULL () { 0 } |
34 | sub CXt_SUB () { 1 } |
35 | sub CXt_EVAL () { 2 } |
36 | sub CXt_LOOP () { 3 } |
37 | sub CXt_SUBST () { 4 } |
38 | sub CXt_BLOCK () { 5 } |
39 | |
40 | my $module; # module name (when compiled with -m) |
41 | my %done; # hash keyed by $$op of leaders of basic blocks |
42 | # which have already been done. |
43 | my $leaders; # ref to hash of basic block leaders. Keys are $$op |
44 | # addresses, values are the $op objects themselves. |
45 | my @bblock_todo; # list of leaders of basic blocks that need visiting |
46 | # sometime. |
47 | my @cc_todo; # list of tuples defining what PP code needs to be |
48 | # saved (e.g. CV, main or PMOP repl code). Each tuple |
49 | # is [$name, $root, $start, @padlist]. PMOP repl code |
50 | # tuples inherit padlist. |
51 | my @stack; # shadows perl's stack when contents are known. |
52 | # Values are objects derived from class B::Stackobj |
53 | my @pad; # Lexicals in current pad as Stackobj-derived objects |
54 | my @padlist; # Copy of current padlist so PMOP repl code can find it |
55 | my @cxstack; # Shadows the (compile-time) cxstack for next,last,redo |
56 | my $jmpbuf_ix = 0; # Next free index for dynamically allocated jmpbufs |
57 | my %constobj; # OP_CONST constants as Stackobj-derived objects |
58 | # keyed by $$sv. |
59 | my $need_freetmps = 0; # We may postpone FREETMPS to the end of each basic |
60 | # block or even to the end of each loop of blocks, |
61 | # depending on optimisation options. |
62 | my $know_op = 0; # Set when C variable op already holds the right op |
63 | # (from an immediately preceding DOOP(ppname)). |
64 | my $errors = 0; # Number of errors encountered |
65 | my %skip_stack; # Hash of PP names which don't need write_back_stack |
66 | my %skip_lexicals; # Hash of PP names which don't need write_back_lexicals |
67 | my %skip_invalidate; # Hash of PP names which don't need invalidate_lexicals |
68 | my %ignore_op; # Hash of ops which do nothing except returning op_next |
69 | |
70 | BEGIN { |
71 | foreach (qw(pp_scalar pp_regcmaybe pp_lineseq pp_scope pp_null)) { |
72 | $ignore_op{$_} = 1; |
73 | } |
74 | } |
75 | |
76 | my @unused_sub_packages; # list of packages (given by -u options) to search |
77 | # explicitly and save every sub we find there, even |
78 | # if apparently unused (could be only referenced from |
79 | # an eval "" or from a $SIG{FOO} = "bar"). |
80 | |
81 | my ($module_name); |
82 | my ($debug_op, $debug_stack, $debug_cxstack, $debug_pad, $debug_runtime, |
83 | $debug_shadow, $debug_queue, $debug_lineno, $debug_timings); |
84 | |
85 | # Optimisation options. On the command line, use hyphens instead of |
86 | # underscores for compatibility with gcc-style options. We use |
87 | # underscores here because they are OK in (strict) barewords. |
88 | my ($freetmps_each_bblock, $freetmps_each_loop, $omit_taint); |
89 | my %optimise = (freetmps_each_bblock => \$freetmps_each_bblock, |
90 | freetmps_each_loop => \$freetmps_each_loop, |
91 | omit_taint => \$omit_taint); |
92 | # perl patchlevel to generate code for (defaults to current patchlevel) |
93 | my $patchlevel = int(0.5 + 1000 * ($] - 5)); |
94 | |
95 | # Could rewrite push_runtime() and output_runtime() to use a |
96 | # temporary file if memory is at a premium. |
97 | my $ppname; # name of current fake PP function |
98 | my $runtime_list_ref; |
99 | my $declare_ref; # Hash ref keyed by C variable type of declarations. |
100 | |
101 | my @pp_list; # list of [$ppname, $runtime_list_ref, $declare_ref] |
102 | # tuples to be written out. |
103 | |
104 | my ($init, $decl); |
105 | |
106 | sub init_hash { map { $_ => 1 } @_ } |
107 | |
108 | # |
109 | # Initialise the hashes for the default PP functions where we can avoid |
110 | # either write_back_stack, write_back_lexicals or invalidate_lexicals. |
111 | # |
112 | %skip_lexicals = init_hash qw(pp_enter pp_enterloop); |
113 | %skip_invalidate = init_hash qw(pp_enter pp_enterloop); |
114 | |
115 | sub debug { |
116 | if ($debug_runtime) { |
117 | warn(@_); |
118 | } else { |
119 | runtime(map { chomp; "/* $_ */"} @_); |
120 | } |
121 | } |
122 | |
123 | sub declare { |
124 | my ($type, $var) = @_; |
125 | push(@{$declare_ref->{$type}}, $var); |
126 | } |
127 | |
128 | sub push_runtime { |
129 | push(@$runtime_list_ref, @_); |
130 | warn join("\n", @_) . "\n" if $debug_runtime; |
131 | } |
132 | |
133 | sub save_runtime { |
134 | push(@pp_list, [$ppname, $runtime_list_ref, $declare_ref]); |
135 | } |
136 | |
137 | sub output_runtime { |
138 | my $ppdata; |
139 | print qq(#include "cc_runtime.h"\n); |
140 | foreach $ppdata (@pp_list) { |
141 | my ($name, $runtime, $declare) = @$ppdata; |
142 | print "\nstatic\nPP($name)\n{\n"; |
143 | my ($type, $varlist, $line); |
144 | while (($type, $varlist) = each %$declare) { |
145 | print "\t$type ", join(", ", @$varlist), ";\n"; |
146 | } |
147 | foreach $line (@$runtime) { |
148 | print $line, "\n"; |
149 | } |
150 | print "}\n"; |
151 | } |
152 | } |
153 | |
154 | sub runtime { |
155 | my $line; |
156 | foreach $line (@_) { |
157 | push_runtime("\t$line"); |
158 | } |
159 | } |
160 | |
161 | sub init_pp { |
162 | $ppname = shift; |
163 | $runtime_list_ref = []; |
164 | $declare_ref = {}; |
165 | runtime("djSP;"); |
166 | declare("I32", "oldsave"); |
167 | declare("SV", "**svp"); |
168 | map { declare("SV", "*$_") } qw(sv src dst left right); |
169 | declare("MAGIC", "*mg"); |
170 | $decl->add("static OP * $ppname _((ARGSproto));"); |
171 | debug "init_pp: $ppname\n" if $debug_queue; |
172 | } |
173 | |
174 | # Initialise runtime_callback function for Stackobj class |
175 | BEGIN { B::Stackobj::set_callback(\&runtime) } |
176 | |
177 | # Initialise saveoptree_callback for B::C class |
178 | sub cc_queue { |
179 | my ($name, $root, $start, @pl) = @_; |
180 | debug "cc_queue: name $name, root $root, start $start, padlist (@pl)\n" |
181 | if $debug_queue; |
182 | if ($name eq "*ignore*") { |
183 | $name = 0; |
184 | } else { |
185 | push(@cc_todo, [$name, $root, $start, (@pl ? @pl : @padlist)]); |
186 | } |
187 | my $fakeop = new B::FAKEOP ("next" => 0, sibling => 0, ppaddr => $name); |
188 | $start = $fakeop->save; |
189 | debug "cc_queue: name $name returns $start\n" if $debug_queue; |
190 | return $start; |
191 | } |
192 | BEGIN { B::C::set_callback(\&cc_queue) } |
193 | |
194 | sub valid_int { $_[0]->{flags} & VALID_INT } |
195 | sub valid_double { $_[0]->{flags} & VALID_DOUBLE } |
196 | sub valid_numeric { $_[0]->{flags} & (VALID_INT | VALID_DOUBLE) } |
197 | sub valid_sv { $_[0]->{flags} & VALID_SV } |
198 | |
199 | sub top_int { @stack ? $stack[-1]->as_int : "TOPi" } |
200 | sub top_double { @stack ? $stack[-1]->as_double : "TOPn" } |
201 | sub top_numeric { @stack ? $stack[-1]->as_numeric : "TOPn" } |
202 | sub top_sv { @stack ? $stack[-1]->as_sv : "TOPs" } |
203 | sub top_bool { @stack ? $stack[-1]->as_numeric : "SvTRUE(TOPs)" } |
204 | |
205 | sub pop_int { @stack ? (pop @stack)->as_int : "POPi" } |
206 | sub pop_double { @stack ? (pop @stack)->as_double : "POPn" } |
207 | sub pop_numeric { @stack ? (pop @stack)->as_numeric : "POPn" } |
208 | sub pop_sv { @stack ? (pop @stack)->as_sv : "POPs" } |
209 | sub pop_bool { |
210 | if (@stack) { |
211 | return ((pop @stack)->as_numeric); |
212 | } else { |
213 | # Careful: POPs has an auto-decrement and SvTRUE evaluates |
214 | # its argument more than once. |
215 | runtime("sv = POPs;"); |
216 | return "SvTRUE(sv)"; |
217 | } |
218 | } |
219 | |
220 | sub write_back_lexicals { |
221 | my $avoid = shift || 0; |
222 | debug "write_back_lexicals($avoid) called from @{[(caller(1))[3]]}\n" |
223 | if $debug_shadow; |
224 | my $lex; |
225 | foreach $lex (@pad) { |
226 | next unless ref($lex); |
227 | $lex->write_back unless $lex->{flags} & $avoid; |
228 | } |
229 | } |
230 | |
231 | sub write_back_stack { |
232 | my $obj; |
233 | return unless @stack; |
234 | runtime(sprintf("EXTEND(sp, %d);", scalar(@stack))); |
235 | foreach $obj (@stack) { |
236 | runtime(sprintf("PUSHs((SV*)%s);", $obj->as_sv)); |
237 | } |
238 | @stack = (); |
239 | } |
240 | |
241 | sub invalidate_lexicals { |
242 | my $avoid = shift || 0; |
243 | debug "invalidate_lexicals($avoid) called from @{[(caller(1))[3]]}\n" |
244 | if $debug_shadow; |
245 | my $lex; |
246 | foreach $lex (@pad) { |
247 | next unless ref($lex); |
248 | $lex->invalidate unless $lex->{flags} & $avoid; |
249 | } |
250 | } |
251 | |
252 | sub reload_lexicals { |
253 | my $lex; |
254 | foreach $lex (@pad) { |
255 | next unless ref($lex); |
256 | my $type = $lex->{type}; |
257 | if ($type == T_INT) { |
258 | $lex->as_int; |
259 | } elsif ($type == T_DOUBLE) { |
260 | $lex->as_double; |
261 | } else { |
262 | $lex->as_sv; |
263 | } |
264 | } |
265 | } |
266 | |
267 | { |
268 | package B::Pseudoreg; |
269 | # |
270 | # This class allocates pseudo-registers (OK, so they're C variables). |
271 | # |
272 | my %alloc; # Keyed by variable name. A value of 1 means the |
273 | # variable has been declared. A value of 2 means |
274 | # it's in use. |
275 | |
276 | sub new_scope { %alloc = () } |
277 | |
278 | sub new ($$$) { |
279 | my ($class, $type, $prefix) = @_; |
280 | my ($ptr, $i, $varname, $status, $obj); |
281 | $prefix =~ s/^(\**)//; |
282 | $ptr = $1; |
283 | $i = 0; |
284 | do { |
285 | $varname = "$prefix$i"; |
286 | $status = $alloc{$varname}; |
287 | } while $status == 2; |
288 | if ($status != 1) { |
289 | # Not declared yet |
290 | B::CC::declare($type, "$ptr$varname"); |
291 | $alloc{$varname} = 2; # declared and in use |
292 | } |
293 | $obj = bless \$varname, $class; |
294 | return $obj; |
295 | } |
296 | sub DESTROY { |
297 | my $obj = shift; |
298 | $alloc{$$obj} = 1; # no longer in use but still declared |
299 | } |
300 | } |
301 | { |
302 | package B::Shadow; |
303 | # |
304 | # This class gives a standard API for a perl object to shadow a |
305 | # C variable and only generate reloads/write-backs when necessary. |
306 | # |
307 | # Use $obj->load($foo) instead of runtime("shadowed_c_var = foo"). |
308 | # Use $obj->write_back whenever shadowed_c_var needs to be up to date. |
309 | # Use $obj->invalidate whenever an unknown function may have |
310 | # set shadow itself. |
311 | |
312 | sub new { |
313 | my ($class, $write_back) = @_; |
314 | # Object fields are perl shadow variable, validity flag |
315 | # (for *C* variable) and callback sub for write_back |
316 | # (passed perl shadow variable as argument). |
317 | bless [undef, 1, $write_back], $class; |
318 | } |
319 | sub load { |
320 | my ($obj, $newval) = @_; |
321 | $obj->[1] = 0; # C variable no longer valid |
322 | $obj->[0] = $newval; |
323 | } |
324 | sub write_back { |
325 | my $obj = shift; |
326 | if (!($obj->[1])) { |
327 | $obj->[1] = 1; # C variable will now be valid |
328 | &{$obj->[2]}($obj->[0]); |
329 | } |
330 | } |
331 | sub invalidate { $_[0]->[1] = 0 } # force C variable to be invalid |
332 | } |
333 | my $curcop = new B::Shadow (sub { |
334 | my $opsym = shift->save; |
81009501 |
335 | runtime("PL_curcop = (COP*)$opsym;"); |
a798dbf2 |
336 | }); |
337 | |
338 | # |
339 | # Context stack shadowing. Mimics stuff in pp_ctl.c, cop.h and so on. |
340 | # |
341 | sub dopoptoloop { |
342 | my $cxix = $#cxstack; |
343 | while ($cxix >= 0 && $cxstack[$cxix]->{type} != CXt_LOOP) { |
344 | $cxix--; |
345 | } |
346 | debug "dopoptoloop: returning $cxix" if $debug_cxstack; |
347 | return $cxix; |
348 | } |
349 | |
350 | sub dopoptolabel { |
351 | my $label = shift; |
352 | my $cxix = $#cxstack; |
353 | while ($cxix >= 0 && $cxstack[$cxix]->{type} != CXt_LOOP |
354 | && $cxstack[$cxix]->{label} ne $label) { |
355 | $cxix--; |
356 | } |
357 | debug "dopoptolabel: returning $cxix" if $debug_cxstack; |
358 | return $cxix; |
359 | } |
360 | |
361 | sub error { |
362 | my $format = shift; |
363 | my $file = $curcop->[0]->filegv->SV->PV; |
364 | my $line = $curcop->[0]->line; |
365 | $errors++; |
366 | if (@_) { |
367 | warn sprintf("%s:%d: $format\n", $file, $line, @_); |
368 | } else { |
369 | warn sprintf("%s:%d: %s\n", $file, $line, $format); |
370 | } |
371 | } |
372 | |
373 | # |
374 | # Load pad takes (the elements of) a PADLIST as arguments and loads |
375 | # up @pad with Stackobj-derived objects which represent those lexicals. |
376 | # If/when perl itself can generate type information (my int $foo) then |
377 | # we'll take advantage of that here. Until then, we'll use various hacks |
378 | # to tell the compiler when we want a lexical to be a particular type |
379 | # or to be a register. |
380 | # |
381 | sub load_pad { |
382 | my ($namelistav, $valuelistav) = @_; |
383 | @padlist = @_; |
384 | my @namelist = $namelistav->ARRAY; |
385 | my @valuelist = $valuelistav->ARRAY; |
386 | my $ix; |
387 | @pad = (); |
388 | debug "load_pad: $#namelist names, $#valuelist values\n" if $debug_pad; |
389 | # Temporary lexicals don't get named so it's possible for @valuelist |
390 | # to be strictly longer than @namelist. We count $ix up to the end of |
391 | # @valuelist but index into @namelist for the name. Any temporaries which |
392 | # run off the end of @namelist will make $namesv undefined and we treat |
393 | # that the same as having an explicit SPECIAL sv_undef object in @namelist. |
394 | # [XXX If/when @_ becomes a lexical, we must start at 0 here.] |
395 | for ($ix = 1; $ix < @valuelist; $ix++) { |
396 | my $namesv = $namelist[$ix]; |
397 | my $type = T_UNKNOWN; |
398 | my $flags = 0; |
399 | my $name = "tmp$ix"; |
400 | my $class = class($namesv); |
401 | if (!defined($namesv) || $class eq "SPECIAL") { |
81009501 |
402 | # temporaries have &PL_sv_undef instead of a PVNV for a name |
a798dbf2 |
403 | $flags = VALID_SV|TEMPORARY|REGISTER; |
404 | } else { |
405 | if ($namesv->PV =~ /^\$(.*)_([di])(r?)$/) { |
406 | $name = $1; |
407 | if ($2 eq "i") { |
408 | $type = T_INT; |
409 | $flags = VALID_SV|VALID_INT; |
410 | } elsif ($2 eq "d") { |
411 | $type = T_DOUBLE; |
412 | $flags = VALID_SV|VALID_DOUBLE; |
413 | } |
414 | $flags |= REGISTER if $3; |
415 | } |
416 | } |
417 | $pad[$ix] = new B::Stackobj::Padsv ($type, $flags, $ix, |
418 | "i_$name", "d_$name"); |
419 | declare("IV", $type == T_INT ? "i_$name = 0" : "i_$name"); |
420 | declare("double", $type == T_DOUBLE ? "d_$name = 0" : "d_$name"); |
81009501 |
421 | debug sprintf("PL_curpad[$ix] = %s\n", $pad[$ix]->peek) if $debug_pad; |
a798dbf2 |
422 | } |
423 | } |
424 | |
425 | # |
426 | # Debugging stuff |
427 | # |
428 | sub peek_stack { sprintf "stack = %s\n", join(" ", map($_->minipeek, @stack)) } |
429 | |
430 | # |
431 | # OP stuff |
432 | # |
433 | |
434 | sub label { |
435 | my $op = shift; |
436 | # XXX Preserve original label name for "real" labels? |
437 | return sprintf("lab_%x", $$op); |
438 | } |
439 | |
440 | sub write_label { |
441 | my $op = shift; |
442 | push_runtime(sprintf(" %s:", label($op))); |
443 | } |
444 | |
445 | sub loadop { |
446 | my $op = shift; |
447 | my $opsym = $op->save; |
81009501 |
448 | runtime("PL_op = $opsym;") unless $know_op; |
a798dbf2 |
449 | return $opsym; |
450 | } |
451 | |
452 | sub doop { |
453 | my $op = shift; |
454 | my $ppname = $op->ppaddr; |
455 | my $sym = loadop($op); |
456 | runtime("DOOP($ppname);"); |
457 | $know_op = 1; |
458 | return $sym; |
459 | } |
460 | |
461 | sub gimme { |
462 | my $op = shift; |
463 | my $flags = $op->flags; |
464 | return (($flags & OPf_KNOW) ? ($flags & OPf_LIST) : "dowantarray()"); |
465 | } |
466 | |
467 | # |
468 | # Code generation for PP code |
469 | # |
470 | |
471 | sub pp_null { |
472 | my $op = shift; |
473 | return $op->next; |
474 | } |
475 | |
476 | sub pp_stub { |
477 | my $op = shift; |
478 | my $gimme = gimme($op); |
479 | if ($gimme != 1) { |
480 | # XXX Change to push a constant sv_undef Stackobj onto @stack |
481 | write_back_stack(); |
81009501 |
482 | runtime("if ($gimme != G_ARRAY) XPUSHs(&PL_sv_undef);"); |
a798dbf2 |
483 | } |
484 | return $op->next; |
485 | } |
486 | |
487 | sub pp_unstack { |
488 | my $op = shift; |
489 | @stack = (); |
490 | runtime("PP_UNSTACK;"); |
491 | return $op->next; |
492 | } |
493 | |
494 | sub pp_and { |
495 | my $op = shift; |
496 | my $next = $op->next; |
497 | reload_lexicals(); |
498 | unshift(@bblock_todo, $next); |
499 | if (@stack >= 1) { |
500 | my $bool = pop_bool(); |
501 | write_back_stack(); |
44887cfa |
502 | runtime(sprintf("if (!$bool) {XPUSHs(&PL_sv_no); goto %s;}", label($next))); |
a798dbf2 |
503 | } else { |
504 | runtime(sprintf("if (!%s) goto %s;", top_bool(), label($next)), |
505 | "*sp--;"); |
506 | } |
507 | return $op->other; |
508 | } |
509 | |
510 | sub pp_or { |
511 | my $op = shift; |
512 | my $next = $op->next; |
513 | reload_lexicals(); |
514 | unshift(@bblock_todo, $next); |
515 | if (@stack >= 1) { |
44887cfa |
516 | my $bool = pop_bool @stack; |
a798dbf2 |
517 | write_back_stack(); |
44887cfa |
518 | runtime(sprintf("if (%s) { XPUSHs(&PL_sv_yes); goto %s; }", |
519 | $bool, label($next))); |
a798dbf2 |
520 | } else { |
521 | runtime(sprintf("if (%s) goto %s;", top_bool(), label($next)), |
522 | "*sp--;"); |
523 | } |
524 | return $op->other; |
525 | } |
526 | |
527 | sub pp_cond_expr { |
528 | my $op = shift; |
529 | my $false = $op->false; |
530 | unshift(@bblock_todo, $false); |
531 | reload_lexicals(); |
532 | my $bool = pop_bool(); |
533 | write_back_stack(); |
534 | runtime(sprintf("if (!$bool) goto %s;", label($false))); |
535 | return $op->true; |
536 | } |
537 | |
538 | sub pp_padsv { |
539 | my $op = shift; |
540 | my $ix = $op->targ; |
541 | push(@stack, $pad[$ix]); |
542 | if ($op->flags & OPf_MOD) { |
543 | my $private = $op->private; |
544 | if ($private & OPpLVAL_INTRO) { |
81009501 |
545 | runtime("SAVECLEARSV(PL_curpad[$ix]);"); |
a798dbf2 |
546 | } elsif ($private & OPpDEREF) { |
81009501 |
547 | runtime(sprintf("vivify_ref(PL_curpad[%d], %d);", |
a798dbf2 |
548 | $ix, $private & OPpDEREF)); |
549 | $pad[$ix]->invalidate; |
550 | } |
551 | } |
552 | return $op->next; |
553 | } |
554 | |
555 | sub pp_const { |
556 | my $op = shift; |
557 | my $sv = $op->sv; |
558 | my $obj = $constobj{$$sv}; |
559 | if (!defined($obj)) { |
560 | $obj = $constobj{$$sv} = new B::Stackobj::Const ($sv); |
561 | } |
562 | push(@stack, $obj); |
563 | return $op->next; |
564 | } |
565 | |
566 | sub pp_nextstate { |
567 | my $op = shift; |
568 | $curcop->load($op); |
569 | @stack = (); |
570 | debug(sprintf("%s:%d\n", $op->filegv->SV->PV, $op->line)) if $debug_lineno; |
571 | runtime("TAINT_NOT;") unless $omit_taint; |
81009501 |
572 | runtime("sp = PL_stack_base + cxstack[cxstack_ix].blk_oldsp;"); |
a798dbf2 |
573 | if ($freetmps_each_bblock || $freetmps_each_loop) { |
574 | $need_freetmps = 1; |
575 | } else { |
576 | runtime("FREETMPS;"); |
577 | } |
578 | return $op->next; |
579 | } |
580 | |
581 | sub pp_dbstate { |
582 | my $op = shift; |
583 | $curcop->invalidate; # XXX? |
584 | return default_pp($op); |
585 | } |
586 | |
587 | sub pp_rv2gv { $curcop->write_back; default_pp(@_) } |
588 | sub pp_bless { $curcop->write_back; default_pp(@_) } |
589 | sub pp_repeat { $curcop->write_back; default_pp(@_) } |
590 | # The following subs need $curcop->write_back if we decide to support arybase: |
591 | # pp_pos, pp_substr, pp_index, pp_rindex, pp_aslice, pp_lslice, pp_splice |
592 | sub pp_sort { $curcop->write_back; default_pp(@_) } |
593 | sub pp_caller { $curcop->write_back; default_pp(@_) } |
594 | sub pp_reset { $curcop->write_back; default_pp(@_) } |
595 | |
596 | sub pp_gv { |
597 | my $op = shift; |
598 | my $gvsym = $op->gv->save; |
599 | write_back_stack(); |
600 | runtime("XPUSHs((SV*)$gvsym);"); |
601 | return $op->next; |
602 | } |
603 | |
604 | sub pp_gvsv { |
605 | my $op = shift; |
606 | my $gvsym = $op->gv->save; |
607 | write_back_stack(); |
608 | if ($op->private & OPpLVAL_INTRO) { |
609 | runtime("XPUSHs(save_scalar($gvsym));"); |
610 | } else { |
611 | runtime("XPUSHs(GvSV($gvsym));"); |
612 | } |
613 | return $op->next; |
614 | } |
615 | |
616 | sub pp_aelemfast { |
617 | my $op = shift; |
618 | my $gvsym = $op->gv->save; |
619 | my $ix = $op->private; |
620 | my $flag = $op->flags & OPf_MOD; |
621 | write_back_stack(); |
622 | runtime("svp = av_fetch(GvAV($gvsym), $ix, $flag);", |
81009501 |
623 | "PUSHs(svp ? *svp : &PL_sv_undef);"); |
a798dbf2 |
624 | return $op->next; |
625 | } |
626 | |
627 | sub int_binop { |
628 | my ($op, $operator) = @_; |
629 | if ($op->flags & OPf_STACKED) { |
630 | my $right = pop_int(); |
631 | if (@stack >= 1) { |
632 | my $left = top_int(); |
633 | $stack[-1]->set_int(&$operator($left, $right)); |
634 | } else { |
635 | runtime(sprintf("sv_setiv(TOPs, %s);",&$operator("TOPi", $right))); |
636 | } |
637 | } else { |
638 | my $targ = $pad[$op->targ]; |
639 | my $right = new B::Pseudoreg ("IV", "riv"); |
640 | my $left = new B::Pseudoreg ("IV", "liv"); |
641 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int)); |
642 | $targ->set_int(&$operator($$left, $$right)); |
643 | push(@stack, $targ); |
644 | } |
645 | return $op->next; |
646 | } |
647 | |
648 | sub INTS_CLOSED () { 0x1 } |
649 | sub INT_RESULT () { 0x2 } |
650 | sub NUMERIC_RESULT () { 0x4 } |
651 | |
652 | sub numeric_binop { |
653 | my ($op, $operator, $flags) = @_; |
654 | my $force_int = 0; |
655 | $force_int ||= ($flags & INT_RESULT); |
656 | $force_int ||= ($flags & INTS_CLOSED && @stack >= 2 |
657 | && valid_int($stack[-2]) && valid_int($stack[-1])); |
658 | if ($op->flags & OPf_STACKED) { |
659 | my $right = pop_numeric(); |
660 | if (@stack >= 1) { |
661 | my $left = top_numeric(); |
662 | if ($force_int) { |
663 | $stack[-1]->set_int(&$operator($left, $right)); |
664 | } else { |
665 | $stack[-1]->set_numeric(&$operator($left, $right)); |
666 | } |
667 | } else { |
668 | if ($force_int) { |
669 | runtime(sprintf("sv_setiv(TOPs, %s);", |
670 | &$operator("TOPi", $right))); |
671 | } else { |
672 | runtime(sprintf("sv_setnv(TOPs, %s);", |
673 | &$operator("TOPn", $right))); |
674 | } |
675 | } |
676 | } else { |
677 | my $targ = $pad[$op->targ]; |
678 | $force_int ||= ($targ->{type} == T_INT); |
679 | if ($force_int) { |
680 | my $right = new B::Pseudoreg ("IV", "riv"); |
681 | my $left = new B::Pseudoreg ("IV", "liv"); |
682 | runtime(sprintf("$$right = %s; $$left = %s;", |
683 | pop_numeric(), pop_numeric)); |
684 | $targ->set_int(&$operator($$left, $$right)); |
685 | } else { |
686 | my $right = new B::Pseudoreg ("double", "rnv"); |
687 | my $left = new B::Pseudoreg ("double", "lnv"); |
688 | runtime(sprintf("$$right = %s; $$left = %s;", |
689 | pop_numeric(), pop_numeric)); |
690 | $targ->set_numeric(&$operator($$left, $$right)); |
691 | } |
692 | push(@stack, $targ); |
693 | } |
694 | return $op->next; |
695 | } |
696 | |
697 | sub sv_binop { |
698 | my ($op, $operator, $flags) = @_; |
699 | if ($op->flags & OPf_STACKED) { |
700 | my $right = pop_sv(); |
701 | if (@stack >= 1) { |
702 | my $left = top_sv(); |
703 | if ($flags & INT_RESULT) { |
704 | $stack[-1]->set_int(&$operator($left, $right)); |
705 | } elsif ($flags & NUMERIC_RESULT) { |
706 | $stack[-1]->set_numeric(&$operator($left, $right)); |
707 | } else { |
708 | # XXX Does this work? |
709 | runtime(sprintf("sv_setsv($left, %s);", |
710 | &$operator($left, $right))); |
711 | $stack[-1]->invalidate; |
712 | } |
713 | } else { |
714 | my $f; |
715 | if ($flags & INT_RESULT) { |
716 | $f = "sv_setiv"; |
717 | } elsif ($flags & NUMERIC_RESULT) { |
718 | $f = "sv_setnv"; |
719 | } else { |
720 | $f = "sv_setsv"; |
721 | } |
722 | runtime(sprintf("%s(TOPs, %s);", $f, &$operator("TOPs", $right))); |
723 | } |
724 | } else { |
725 | my $targ = $pad[$op->targ]; |
726 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv)); |
727 | if ($flags & INT_RESULT) { |
728 | $targ->set_int(&$operator("left", "right")); |
729 | } elsif ($flags & NUMERIC_RESULT) { |
730 | $targ->set_numeric(&$operator("left", "right")); |
731 | } else { |
732 | # XXX Does this work? |
733 | runtime(sprintf("sv_setsv(%s, %s);", |
734 | $targ->as_sv, &$operator("left", "right"))); |
735 | $targ->invalidate; |
736 | } |
737 | push(@stack, $targ); |
738 | } |
739 | return $op->next; |
740 | } |
741 | |
742 | sub bool_int_binop { |
743 | my ($op, $operator) = @_; |
744 | my $right = new B::Pseudoreg ("IV", "riv"); |
745 | my $left = new B::Pseudoreg ("IV", "liv"); |
746 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int())); |
747 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
748 | $bool->set_int(&$operator($$left, $$right)); |
749 | push(@stack, $bool); |
750 | return $op->next; |
751 | } |
752 | |
753 | sub bool_numeric_binop { |
754 | my ($op, $operator) = @_; |
755 | my $right = new B::Pseudoreg ("double", "rnv"); |
756 | my $left = new B::Pseudoreg ("double", "lnv"); |
757 | runtime(sprintf("$$right = %s; $$left = %s;", |
758 | pop_numeric(), pop_numeric())); |
759 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
760 | $bool->set_numeric(&$operator($$left, $$right)); |
761 | push(@stack, $bool); |
762 | return $op->next; |
763 | } |
764 | |
765 | sub bool_sv_binop { |
766 | my ($op, $operator) = @_; |
767 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv())); |
768 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
769 | $bool->set_numeric(&$operator("left", "right")); |
770 | push(@stack, $bool); |
771 | return $op->next; |
772 | } |
773 | |
774 | sub infix_op { |
775 | my $opname = shift; |
776 | return sub { "$_[0] $opname $_[1]" } |
777 | } |
778 | |
779 | sub prefix_op { |
780 | my $opname = shift; |
781 | return sub { sprintf("%s(%s)", $opname, join(", ", @_)) } |
782 | } |
783 | |
784 | BEGIN { |
785 | my $plus_op = infix_op("+"); |
786 | my $minus_op = infix_op("-"); |
787 | my $multiply_op = infix_op("*"); |
788 | my $divide_op = infix_op("/"); |
789 | my $modulo_op = infix_op("%"); |
790 | my $lshift_op = infix_op("<<"); |
a0d31f98 |
791 | my $rshift_op = infix_op(">>"); |
a798dbf2 |
792 | my $ncmp_op = sub { "($_[0] > $_[1] ? 1 : ($_[0] < $_[1]) ? -1 : 0)" }; |
793 | my $scmp_op = prefix_op("sv_cmp"); |
794 | my $seq_op = prefix_op("sv_eq"); |
795 | my $sne_op = prefix_op("!sv_eq"); |
796 | my $slt_op = sub { "sv_cmp($_[0], $_[1]) < 0" }; |
797 | my $sgt_op = sub { "sv_cmp($_[0], $_[1]) > 0" }; |
798 | my $sle_op = sub { "sv_cmp($_[0], $_[1]) <= 0" }; |
799 | my $sge_op = sub { "sv_cmp($_[0], $_[1]) >= 0" }; |
800 | my $eq_op = infix_op("=="); |
801 | my $ne_op = infix_op("!="); |
802 | my $lt_op = infix_op("<"); |
803 | my $gt_op = infix_op(">"); |
804 | my $le_op = infix_op("<="); |
805 | my $ge_op = infix_op(">="); |
806 | |
807 | # |
808 | # XXX The standard perl PP code has extra handling for |
809 | # some special case arguments of these operators. |
810 | # |
811 | sub pp_add { numeric_binop($_[0], $plus_op, INTS_CLOSED) } |
812 | sub pp_subtract { numeric_binop($_[0], $minus_op, INTS_CLOSED) } |
813 | sub pp_multiply { numeric_binop($_[0], $multiply_op, INTS_CLOSED) } |
814 | sub pp_divide { numeric_binop($_[0], $divide_op) } |
815 | sub pp_modulo { int_binop($_[0], $modulo_op) } # differs from perl's |
816 | sub pp_ncmp { numeric_binop($_[0], $ncmp_op, INT_RESULT) } |
817 | |
818 | sub pp_left_shift { int_binop($_[0], $lshift_op) } |
819 | sub pp_right_shift { int_binop($_[0], $rshift_op) } |
820 | sub pp_i_add { int_binop($_[0], $plus_op) } |
821 | sub pp_i_subtract { int_binop($_[0], $minus_op) } |
822 | sub pp_i_multiply { int_binop($_[0], $multiply_op) } |
823 | sub pp_i_divide { int_binop($_[0], $divide_op) } |
824 | sub pp_i_modulo { int_binop($_[0], $modulo_op) } |
825 | |
826 | sub pp_eq { bool_numeric_binop($_[0], $eq_op) } |
827 | sub pp_ne { bool_numeric_binop($_[0], $ne_op) } |
828 | sub pp_lt { bool_numeric_binop($_[0], $lt_op) } |
829 | sub pp_gt { bool_numeric_binop($_[0], $gt_op) } |
830 | sub pp_le { bool_numeric_binop($_[0], $le_op) } |
831 | sub pp_ge { bool_numeric_binop($_[0], $ge_op) } |
832 | |
833 | sub pp_i_eq { bool_int_binop($_[0], $eq_op) } |
834 | sub pp_i_ne { bool_int_binop($_[0], $ne_op) } |
835 | sub pp_i_lt { bool_int_binop($_[0], $lt_op) } |
836 | sub pp_i_gt { bool_int_binop($_[0], $gt_op) } |
837 | sub pp_i_le { bool_int_binop($_[0], $le_op) } |
838 | sub pp_i_ge { bool_int_binop($_[0], $ge_op) } |
839 | |
840 | sub pp_scmp { sv_binop($_[0], $scmp_op, INT_RESULT) } |
841 | sub pp_slt { bool_sv_binop($_[0], $slt_op) } |
842 | sub pp_sgt { bool_sv_binop($_[0], $sgt_op) } |
843 | sub pp_sle { bool_sv_binop($_[0], $sle_op) } |
844 | sub pp_sge { bool_sv_binop($_[0], $sge_op) } |
845 | sub pp_seq { bool_sv_binop($_[0], $seq_op) } |
846 | sub pp_sne { bool_sv_binop($_[0], $sne_op) } |
847 | } |
848 | |
849 | |
850 | sub pp_sassign { |
851 | my $op = shift; |
852 | my $backwards = $op->private & OPpASSIGN_BACKWARDS; |
853 | my ($dst, $src); |
854 | if (@stack >= 2) { |
855 | $dst = pop @stack; |
856 | $src = pop @stack; |
857 | ($src, $dst) = ($dst, $src) if $backwards; |
858 | my $type = $src->{type}; |
859 | if ($type == T_INT) { |
860 | $dst->set_int($src->as_int); |
861 | } elsif ($type == T_DOUBLE) { |
862 | $dst->set_numeric($src->as_numeric); |
863 | } else { |
864 | $dst->set_sv($src->as_sv); |
865 | } |
866 | push(@stack, $dst); |
867 | } elsif (@stack == 1) { |
868 | if ($backwards) { |
869 | my $src = pop @stack; |
870 | my $type = $src->{type}; |
81009501 |
871 | runtime("if (PL_tainting && PL_tainted) TAINT_NOT;"); |
a798dbf2 |
872 | if ($type == T_INT) { |
873 | runtime sprintf("sv_setiv(TOPs, %s);", $src->as_int); |
874 | } elsif ($type == T_DOUBLE) { |
875 | runtime sprintf("sv_setnv(TOPs, %s);", $src->as_double); |
876 | } else { |
877 | runtime sprintf("sv_setsv(TOPs, %s);", $src->as_sv); |
878 | } |
879 | runtime("SvSETMAGIC(TOPs);"); |
880 | } else { |
b8f1fa48 |
881 | my $dst = $stack[-1]; |
a798dbf2 |
882 | my $type = $dst->{type}; |
883 | runtime("sv = POPs;"); |
884 | runtime("MAYBE_TAINT_SASSIGN_SRC(sv);"); |
885 | if ($type == T_INT) { |
886 | $dst->set_int("SvIV(sv)"); |
887 | } elsif ($type == T_DOUBLE) { |
888 | $dst->set_double("SvNV(sv)"); |
889 | } else { |
890 | runtime("SvSetSV($dst->{sv}, sv);"); |
891 | $dst->invalidate; |
892 | } |
893 | } |
894 | } else { |
895 | if ($backwards) { |
896 | runtime("src = POPs; dst = TOPs;"); |
897 | } else { |
898 | runtime("dst = POPs; src = TOPs;"); |
899 | } |
900 | runtime("MAYBE_TAINT_SASSIGN_SRC(src);", |
901 | "SvSetSV(dst, src);", |
902 | "SvSETMAGIC(dst);", |
903 | "SETs(dst);"); |
904 | } |
905 | return $op->next; |
906 | } |
907 | |
908 | sub pp_preinc { |
909 | my $op = shift; |
910 | if (@stack >= 1) { |
911 | my $obj = $stack[-1]; |
912 | my $type = $obj->{type}; |
913 | if ($type == T_INT || $type == T_DOUBLE) { |
914 | $obj->set_int($obj->as_int . " + 1"); |
915 | } else { |
916 | runtime sprintf("PP_PREINC(%s);", $obj->as_sv); |
917 | $obj->invalidate(); |
918 | } |
919 | } else { |
920 | runtime sprintf("PP_PREINC(TOPs);"); |
921 | } |
922 | return $op->next; |
923 | } |
924 | |
925 | sub pp_pushmark { |
926 | my $op = shift; |
927 | write_back_stack(); |
928 | runtime("PUSHMARK(sp);"); |
929 | return $op->next; |
930 | } |
931 | |
932 | sub pp_list { |
933 | my $op = shift; |
934 | write_back_stack(); |
935 | my $gimme = gimme($op); |
936 | if ($gimme == 1) { # sic |
937 | runtime("POPMARK;"); # need this even though not a "full" pp_list |
938 | } else { |
939 | runtime("PP_LIST($gimme);"); |
940 | } |
941 | return $op->next; |
942 | } |
943 | |
944 | sub pp_entersub { |
945 | my $op = shift; |
946 | write_back_lexicals(REGISTER|TEMPORARY); |
947 | write_back_stack(); |
948 | my $sym = doop($op); |
5cfd8ad4 |
949 | runtime("while (PL_op != ($sym)->op_next && PL_op != (OP*)0 ){"); |
950 | runtime("PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
951 | runtime("SPAGAIN;}"); |
a798dbf2 |
952 | $know_op = 0; |
953 | invalidate_lexicals(REGISTER|TEMPORARY); |
954 | return $op->next; |
955 | } |
956 | |
5cfd8ad4 |
957 | sub pp_goto{ |
958 | |
959 | my $op = shift; |
960 | my $ppname = $op->ppaddr; |
961 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
962 | write_back_stack() unless $skip_stack{$ppname}; |
963 | my $sym=doop($op); |
964 | runtime("if (PL_op != ($sym)->op_next && PL_op != (OP*)0){return PL_op;}"); |
965 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
966 | return $op->next; |
967 | } |
a798dbf2 |
968 | sub pp_enterwrite { |
969 | my $op = shift; |
970 | pp_entersub($op); |
971 | } |
972 | |
973 | sub pp_leavewrite { |
974 | my $op = shift; |
975 | write_back_lexicals(REGISTER|TEMPORARY); |
976 | write_back_stack(); |
977 | my $sym = doop($op); |
978 | # XXX Is this the right way to distinguish between it returning |
979 | # CvSTART(cv) (via doform) and pop_return()? |
81009501 |
980 | runtime("if (PL_op) PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
a798dbf2 |
981 | runtime("SPAGAIN;"); |
982 | $know_op = 0; |
983 | invalidate_lexicals(REGISTER|TEMPORARY); |
984 | return $op->next; |
985 | } |
986 | |
987 | sub doeval { |
988 | my $op = shift; |
989 | $curcop->write_back; |
990 | write_back_lexicals(REGISTER|TEMPORARY); |
991 | write_back_stack(); |
992 | my $sym = loadop($op); |
993 | my $ppaddr = $op->ppaddr; |
994 | runtime("PP_EVAL($ppaddr, ($sym)->op_next);"); |
995 | $know_op = 1; |
996 | invalidate_lexicals(REGISTER|TEMPORARY); |
997 | return $op->next; |
998 | } |
999 | |
1000 | sub pp_entereval { doeval(@_) } |
1001 | sub pp_require { doeval(@_) } |
1002 | sub pp_dofile { doeval(@_) } |
1003 | |
1004 | sub pp_entertry { |
1005 | my $op = shift; |
1006 | $curcop->write_back; |
1007 | write_back_lexicals(REGISTER|TEMPORARY); |
1008 | write_back_stack(); |
1009 | my $sym = doop($op); |
1010 | my $jmpbuf = sprintf("jmpbuf%d", $jmpbuf_ix++); |
1011 | declare("Sigjmp_buf", $jmpbuf); |
1012 | runtime(sprintf("PP_ENTERTRY(%s,%s);", $jmpbuf, label($op->other->next))); |
1013 | invalidate_lexicals(REGISTER|TEMPORARY); |
1014 | return $op->next; |
1015 | } |
1016 | |
1017 | sub pp_grepstart { |
1018 | my $op = shift; |
1019 | if ($need_freetmps && $freetmps_each_loop) { |
1020 | runtime("FREETMPS;"); # otherwise the grepwhile loop messes things up |
1021 | $need_freetmps = 0; |
1022 | } |
1023 | write_back_stack(); |
1024 | doop($op); |
1025 | return $op->next->other; |
1026 | } |
1027 | |
1028 | sub pp_mapstart { |
1029 | my $op = shift; |
1030 | if ($need_freetmps && $freetmps_each_loop) { |
1031 | runtime("FREETMPS;"); # otherwise the mapwhile loop messes things up |
1032 | $need_freetmps = 0; |
1033 | } |
1034 | write_back_stack(); |
1035 | doop($op); |
1036 | return $op->next->other; |
1037 | } |
1038 | |
1039 | sub pp_grepwhile { |
1040 | my $op = shift; |
1041 | my $next = $op->next; |
1042 | unshift(@bblock_todo, $next); |
1043 | write_back_lexicals(); |
1044 | write_back_stack(); |
1045 | my $sym = doop($op); |
1046 | # pp_grepwhile can return either op_next or op_other and we need to |
1047 | # be able to distinguish the two at runtime. Since it's possible for |
1048 | # both ops to be "inlined", the fields could both be zero. To get |
1049 | # around that, we hack op_next to be our own op (purely because we |
1050 | # know it's a non-NULL pointer and can't be the same as op_other). |
1051 | $init->add("((LOGOP*)$sym)->op_next = $sym;"); |
81009501 |
1052 | runtime(sprintf("if (PL_op == ($sym)->op_next) goto %s;", label($next))); |
a798dbf2 |
1053 | $know_op = 0; |
1054 | return $op->other; |
1055 | } |
1056 | |
1057 | sub pp_mapwhile { |
1058 | pp_grepwhile(@_); |
1059 | } |
1060 | |
1061 | sub pp_return { |
1062 | my $op = shift; |
1063 | write_back_lexicals(REGISTER|TEMPORARY); |
1064 | write_back_stack(); |
1065 | doop($op); |
7de5877e |
1066 | runtime("PUTBACK;", "return (PL_op)?PL_op->op_next:0;"); |
a798dbf2 |
1067 | $know_op = 0; |
1068 | return $op->next; |
1069 | } |
1070 | |
1071 | sub nyi { |
1072 | my $op = shift; |
1073 | warn sprintf("%s not yet implemented properly\n", $op->ppaddr); |
1074 | return default_pp($op); |
1075 | } |
1076 | |
1077 | sub pp_range { |
1078 | my $op = shift; |
1079 | my $flags = $op->flags; |
1080 | if (!($flags & OPf_KNOW)) { |
1081 | error("context of range unknown at compile-time"); |
1082 | } |
1083 | write_back_lexicals(); |
1084 | write_back_stack(); |
1085 | if (!($flags & OPf_LIST)) { |
1086 | # We need to save our UNOP structure since pp_flop uses |
1087 | # it to find and adjust out targ. We don't need it ourselves. |
1088 | $op->save; |
81009501 |
1089 | runtime sprintf("if (SvTRUE(PL_curpad[%d])) goto %s;", |
a798dbf2 |
1090 | $op->targ, label($op->false)); |
1091 | unshift(@bblock_todo, $op->false); |
1092 | } |
1093 | return $op->true; |
1094 | } |
1095 | |
1096 | sub pp_flip { |
1097 | my $op = shift; |
1098 | my $flags = $op->flags; |
1099 | if (!($flags & OPf_KNOW)) { |
1100 | error("context of flip unknown at compile-time"); |
1101 | } |
1102 | if ($flags & OPf_LIST) { |
1103 | return $op->first->false; |
1104 | } |
1105 | write_back_lexicals(); |
1106 | write_back_stack(); |
1107 | # We need to save our UNOP structure since pp_flop uses |
1108 | # it to find and adjust out targ. We don't need it ourselves. |
1109 | $op->save; |
1110 | my $ix = $op->targ; |
1111 | my $rangeix = $op->first->targ; |
1112 | runtime(($op->private & OPpFLIP_LINENUM) ? |
81009501 |
1113 | "if (PL_last_in_gv && SvIV(TOPs) == IoLINES(GvIOp(PL_last_in_gv))) {" |
a798dbf2 |
1114 | : "if (SvTRUE(TOPs)) {"); |
81009501 |
1115 | runtime("\tsv_setiv(PL_curpad[$rangeix], 1);"); |
a798dbf2 |
1116 | if ($op->flags & OPf_SPECIAL) { |
81009501 |
1117 | runtime("sv_setiv(PL_curpad[$ix], 1);"); |
a798dbf2 |
1118 | } else { |
81009501 |
1119 | runtime("\tsv_setiv(PL_curpad[$ix], 0);", |
a798dbf2 |
1120 | "\tsp--;", |
1121 | sprintf("\tgoto %s;", label($op->first->false))); |
1122 | } |
1123 | runtime("}", |
81009501 |
1124 | qq{sv_setpv(PL_curpad[$ix], "");}, |
1125 | "SETs(PL_curpad[$ix]);"); |
a798dbf2 |
1126 | $know_op = 0; |
1127 | return $op->next; |
1128 | } |
1129 | |
1130 | sub pp_flop { |
1131 | my $op = shift; |
1132 | default_pp($op); |
1133 | $know_op = 0; |
1134 | return $op->next; |
1135 | } |
1136 | |
1137 | sub enterloop { |
1138 | my $op = shift; |
1139 | my $nextop = $op->nextop; |
1140 | my $lastop = $op->lastop; |
1141 | my $redoop = $op->redoop; |
1142 | $curcop->write_back; |
1143 | debug "enterloop: pushing on cxstack" if $debug_cxstack; |
1144 | push(@cxstack, { |
1145 | type => CXt_LOOP, |
1146 | op => $op, |
1147 | "label" => $curcop->[0]->label, |
1148 | nextop => $nextop, |
1149 | lastop => $lastop, |
1150 | redoop => $redoop |
1151 | }); |
1152 | $nextop->save; |
1153 | $lastop->save; |
1154 | $redoop->save; |
1155 | return default_pp($op); |
1156 | } |
1157 | |
1158 | sub pp_enterloop { enterloop(@_) } |
1159 | sub pp_enteriter { enterloop(@_) } |
1160 | |
1161 | sub pp_leaveloop { |
1162 | my $op = shift; |
1163 | if (!@cxstack) { |
1164 | die "panic: leaveloop"; |
1165 | } |
1166 | debug "leaveloop: popping from cxstack" if $debug_cxstack; |
1167 | pop(@cxstack); |
1168 | return default_pp($op); |
1169 | } |
1170 | |
1171 | sub pp_next { |
1172 | my $op = shift; |
1173 | my $cxix; |
1174 | if ($op->flags & OPf_SPECIAL) { |
1175 | $cxix = dopoptoloop(); |
1176 | if ($cxix < 0) { |
1177 | error('"next" used outside loop'); |
1178 | return $op->next; # ignore the op |
1179 | } |
1180 | } else { |
1181 | $cxix = dopoptolabel($op->pv); |
1182 | if ($cxix < 0) { |
1183 | error('Label not found at compile time for "next %s"', $op->pv); |
1184 | return $op->next; # ignore the op |
1185 | } |
1186 | } |
1187 | default_pp($op); |
1188 | my $nextop = $cxstack[$cxix]->{nextop}; |
1189 | push(@bblock_todo, $nextop); |
1190 | runtime(sprintf("goto %s;", label($nextop))); |
1191 | return $op->next; |
1192 | } |
1193 | |
1194 | sub pp_redo { |
1195 | my $op = shift; |
1196 | my $cxix; |
1197 | if ($op->flags & OPf_SPECIAL) { |
1198 | $cxix = dopoptoloop(); |
1199 | if ($cxix < 0) { |
1200 | error('"redo" used outside loop'); |
1201 | return $op->next; # ignore the op |
1202 | } |
1203 | } else { |
1204 | $cxix = dopoptolabel($op->pv); |
1205 | if ($cxix < 0) { |
1206 | error('Label not found at compile time for "redo %s"', $op->pv); |
1207 | return $op->next; # ignore the op |
1208 | } |
1209 | } |
1210 | default_pp($op); |
1211 | my $redoop = $cxstack[$cxix]->{redoop}; |
1212 | push(@bblock_todo, $redoop); |
1213 | runtime(sprintf("goto %s;", label($redoop))); |
1214 | return $op->next; |
1215 | } |
1216 | |
1217 | sub pp_last { |
1218 | my $op = shift; |
1219 | my $cxix; |
1220 | if ($op->flags & OPf_SPECIAL) { |
1221 | $cxix = dopoptoloop(); |
1222 | if ($cxix < 0) { |
1223 | error('"last" used outside loop'); |
1224 | return $op->next; # ignore the op |
1225 | } |
1226 | } else { |
1227 | $cxix = dopoptolabel($op->pv); |
1228 | if ($cxix < 0) { |
1229 | error('Label not found at compile time for "last %s"', $op->pv); |
1230 | return $op->next; # ignore the op |
1231 | } |
1232 | # XXX Add support for "last" to leave non-loop blocks |
1233 | if ($cxstack[$cxix]->{type} != CXt_LOOP) { |
1234 | error('Use of "last" for non-loop blocks is not yet implemented'); |
1235 | return $op->next; # ignore the op |
1236 | } |
1237 | } |
1238 | default_pp($op); |
1239 | my $lastop = $cxstack[$cxix]->{lastop}->next; |
1240 | push(@bblock_todo, $lastop); |
1241 | runtime(sprintf("goto %s;", label($lastop))); |
1242 | return $op->next; |
1243 | } |
1244 | |
1245 | sub pp_subst { |
1246 | my $op = shift; |
1247 | write_back_lexicals(); |
1248 | write_back_stack(); |
1249 | my $sym = doop($op); |
1250 | my $replroot = $op->pmreplroot; |
1251 | if ($$replroot) { |
81009501 |
1252 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplroot) goto %s;", |
a798dbf2 |
1253 | $sym, label($replroot)); |
1254 | $op->pmreplstart->save; |
1255 | push(@bblock_todo, $replroot); |
1256 | } |
1257 | invalidate_lexicals(); |
1258 | return $op->next; |
1259 | } |
1260 | |
1261 | sub pp_substcont { |
1262 | my $op = shift; |
1263 | write_back_lexicals(); |
1264 | write_back_stack(); |
1265 | doop($op); |
1266 | my $pmop = $op->other; |
0cc1d052 |
1267 | # warn sprintf("substcont: op = %s, pmop = %s\n", |
1268 | # peekop($op), peekop($pmop));#debug |
1269 | # my $pmopsym = objsym($pmop); |
a798dbf2 |
1270 | my $pmopsym = $pmop->save; # XXX can this recurse? |
0cc1d052 |
1271 | # warn "pmopsym = $pmopsym\n";#debug |
81009501 |
1272 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplstart) goto %s;", |
a798dbf2 |
1273 | $pmopsym, label($pmop->pmreplstart)); |
1274 | invalidate_lexicals(); |
1275 | return $pmop->next; |
1276 | } |
1277 | |
1278 | sub default_pp { |
1279 | my $op = shift; |
1280 | my $ppname = $op->ppaddr; |
1281 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
1282 | write_back_stack() unless $skip_stack{$ppname}; |
1283 | doop($op); |
1284 | # XXX If the only way that ops can write to a TEMPORARY lexical is |
1285 | # when it's named in $op->targ then we could call |
1286 | # invalidate_lexicals(TEMPORARY) and avoid having to write back all |
1287 | # the temporaries. For now, we'll play it safe and write back the lot. |
1288 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
1289 | return $op->next; |
1290 | } |
1291 | |
1292 | sub compile_op { |
1293 | my $op = shift; |
1294 | my $ppname = $op->ppaddr; |
1295 | if (exists $ignore_op{$ppname}) { |
1296 | return $op->next; |
1297 | } |
1298 | debug peek_stack() if $debug_stack; |
1299 | if ($debug_op) { |
1300 | debug sprintf("%s [%s]\n", |
1301 | peekop($op), |
1302 | $op->flags & OPf_STACKED ? "OPf_STACKED" : $op->targ); |
1303 | } |
1304 | no strict 'refs'; |
1305 | if (defined(&$ppname)) { |
1306 | $know_op = 0; |
1307 | return &$ppname($op); |
1308 | } else { |
1309 | return default_pp($op); |
1310 | } |
1311 | } |
1312 | |
1313 | sub compile_bblock { |
1314 | my $op = shift; |
1315 | #warn "compile_bblock: ", peekop($op), "\n"; # debug |
1316 | write_label($op); |
1317 | $know_op = 0; |
1318 | do { |
1319 | $op = compile_op($op); |
1320 | } while (defined($op) && $$op && !exists($leaders->{$$op})); |
1321 | write_back_stack(); # boo hoo: big loss |
1322 | reload_lexicals(); |
1323 | return $op; |
1324 | } |
1325 | |
1326 | sub cc { |
1327 | my ($name, $root, $start, @padlist) = @_; |
1328 | my $op; |
1329 | init_pp($name); |
1330 | load_pad(@padlist); |
1331 | B::Pseudoreg->new_scope; |
1332 | @cxstack = (); |
1333 | if ($debug_timings) { |
1334 | warn sprintf("Basic block analysis at %s\n", timing_info); |
1335 | } |
1336 | $leaders = find_leaders($root, $start); |
1337 | @bblock_todo = ($start, values %$leaders); |
1338 | if ($debug_timings) { |
1339 | warn sprintf("Compilation at %s\n", timing_info); |
1340 | } |
1341 | while (@bblock_todo) { |
1342 | $op = shift @bblock_todo; |
1343 | #warn sprintf("Considering basic block %s\n", peekop($op)); # debug |
1344 | next if !defined($op) || !$$op || $done{$$op}; |
1345 | #warn "...compiling it\n"; # debug |
1346 | do { |
1347 | $done{$$op} = 1; |
1348 | $op = compile_bblock($op); |
1349 | if ($need_freetmps && $freetmps_each_bblock) { |
1350 | runtime("FREETMPS;"); |
1351 | $need_freetmps = 0; |
1352 | } |
1353 | } while defined($op) && $$op && !$done{$$op}; |
1354 | if ($need_freetmps && $freetmps_each_loop) { |
1355 | runtime("FREETMPS;"); |
1356 | $need_freetmps = 0; |
1357 | } |
1358 | if (!$$op) { |
7de5877e |
1359 | runtime("PUTBACK;","return (PL_op)?PL_op->op_next:0;"); |
a798dbf2 |
1360 | } elsif ($done{$$op}) { |
1361 | runtime(sprintf("goto %s;", label($op))); |
1362 | } |
1363 | } |
1364 | if ($debug_timings) { |
1365 | warn sprintf("Saving runtime at %s\n", timing_info); |
1366 | } |
1367 | save_runtime(); |
1368 | } |
1369 | |
1370 | sub cc_recurse { |
1371 | my $ccinfo; |
1372 | my $start; |
1373 | $start = cc_queue(@_) if @_; |
1374 | while ($ccinfo = shift @cc_todo) { |
1375 | cc(@$ccinfo); |
1376 | } |
1377 | return $start; |
1378 | } |
1379 | |
1380 | sub cc_obj { |
1381 | my ($name, $cvref) = @_; |
1382 | my $cv = svref_2object($cvref); |
1383 | my @padlist = $cv->PADLIST->ARRAY; |
1384 | my $curpad_sym = $padlist[1]->save; |
1385 | cc_recurse($name, $cv->ROOT, $cv->START, @padlist); |
1386 | } |
1387 | |
1388 | sub cc_main { |
1389 | my @comppadlist = comppadlist->ARRAY; |
0cc1d052 |
1390 | my $curpad_nam = $comppadlist[0]->save; |
1391 | my $curpad_sym = $comppadlist[1]->save; |
1392 | my $init_av = init_av->save; |
1393 | my $inc_hv = svref_2object(\%INC)->save; |
1394 | my $inc_av = svref_2object(\@INC)->save; |
a798dbf2 |
1395 | my $start = cc_recurse("pp_main", main_root, main_start, @comppadlist); |
0cc1d052 |
1396 | save_unused_subs(); |
a798dbf2 |
1397 | cc_recurse(); |
1398 | |
1399 | return if $errors; |
1400 | if (!defined($module)) { |
81009501 |
1401 | $init->add(sprintf("PL_main_root = s\\_%x;", ${main_root()}), |
1402 | "PL_main_start = $start;", |
5cfd8ad4 |
1403 | "PL_curpad = AvARRAY($curpad_sym);", |
0cc1d052 |
1404 | "PL_initav = $init_av;", |
1405 | "GvHV(PL_incgv) = $inc_hv;", |
1406 | "GvAV(PL_incgv) = $inc_av;", |
5cfd8ad4 |
1407 | "av_store(CvPADLIST(PL_main_cv),0,SvREFCNT_inc($curpad_nam));", |
44887cfa |
1408 | "av_store(CvPADLIST(PL_main_cv),1,SvREFCNT_inc($curpad_sym));", |
1409 | ); |
1410 | |
a798dbf2 |
1411 | } |
1412 | output_boilerplate(); |
1413 | print "\n"; |
1414 | output_all("perl_init"); |
1415 | output_runtime(); |
1416 | print "\n"; |
1417 | output_main(); |
1418 | if (defined($module)) { |
1419 | my $cmodule = $module; |
1420 | $cmodule =~ s/::/__/g; |
1421 | print <<"EOT"; |
1422 | |
1423 | #include "XSUB.h" |
1424 | XS(boot_$cmodule) |
1425 | { |
1426 | dXSARGS; |
1427 | perl_init(); |
1428 | ENTER; |
1429 | SAVETMPS; |
81009501 |
1430 | SAVESPTR(PL_curpad); |
1431 | SAVESPTR(PL_op); |
1432 | PL_curpad = AvARRAY($curpad_sym); |
1433 | PL_op = $start; |
a798dbf2 |
1434 | pp_main(ARGS); |
1435 | FREETMPS; |
1436 | LEAVE; |
81009501 |
1437 | ST(0) = &PL_sv_yes; |
a798dbf2 |
1438 | XSRETURN(1); |
1439 | } |
1440 | EOT |
1441 | } |
1442 | if ($debug_timings) { |
1443 | warn sprintf("Done at %s\n", timing_info); |
1444 | } |
1445 | } |
1446 | |
1447 | sub compile { |
1448 | my @options = @_; |
1449 | my ($option, $opt, $arg); |
1450 | OPTION: |
1451 | while ($option = shift @options) { |
1452 | if ($option =~ /^-(.)(.*)/) { |
1453 | $opt = $1; |
1454 | $arg = $2; |
1455 | } else { |
1456 | unshift @options, $option; |
1457 | last OPTION; |
1458 | } |
1459 | if ($opt eq "-" && $arg eq "-") { |
1460 | shift @options; |
1461 | last OPTION; |
1462 | } elsif ($opt eq "o") { |
1463 | $arg ||= shift @options; |
ff06c60c |
1464 | open(STDOUT, ">$arg") or return "open '>$arg': $!\n"; |
a798dbf2 |
1465 | } elsif ($opt eq "n") { |
1466 | $arg ||= shift @options; |
1467 | $module_name = $arg; |
1468 | } elsif ($opt eq "u") { |
1469 | $arg ||= shift @options; |
0cc1d052 |
1470 | mark_unused($arg,undef); |
a798dbf2 |
1471 | } elsif ($opt eq "f") { |
1472 | $arg ||= shift @options; |
1473 | my $value = $arg !~ s/^no-//; |
1474 | $arg =~ s/-/_/g; |
1475 | my $ref = $optimise{$arg}; |
1476 | if (defined($ref)) { |
1477 | $$ref = $value; |
1478 | } else { |
1479 | warn qq(ignoring unknown optimisation option "$arg"\n); |
1480 | } |
1481 | } elsif ($opt eq "O") { |
1482 | $arg = 1 if $arg eq ""; |
1483 | my $ref; |
1484 | foreach $ref (values %optimise) { |
1485 | $$ref = 0; |
1486 | } |
1487 | if ($arg >= 2) { |
1488 | $freetmps_each_loop = 1; |
1489 | } |
1490 | if ($arg >= 1) { |
1491 | $freetmps_each_bblock = 1 unless $freetmps_each_loop; |
1492 | } |
1493 | } elsif ($opt eq "m") { |
1494 | $arg ||= shift @options; |
1495 | $module = $arg; |
1496 | push(@unused_sub_packages, $arg); |
1497 | } elsif ($opt eq "p") { |
1498 | $arg ||= shift @options; |
1499 | $patchlevel = $arg; |
1500 | } elsif ($opt eq "D") { |
1501 | $arg ||= shift @options; |
1502 | foreach $arg (split(//, $arg)) { |
1503 | if ($arg eq "o") { |
1504 | B->debug(1); |
1505 | } elsif ($arg eq "O") { |
1506 | $debug_op = 1; |
1507 | } elsif ($arg eq "s") { |
1508 | $debug_stack = 1; |
1509 | } elsif ($arg eq "c") { |
1510 | $debug_cxstack = 1; |
1511 | } elsif ($arg eq "p") { |
1512 | $debug_pad = 1; |
1513 | } elsif ($arg eq "r") { |
1514 | $debug_runtime = 1; |
1515 | } elsif ($arg eq "S") { |
1516 | $debug_shadow = 1; |
1517 | } elsif ($arg eq "q") { |
1518 | $debug_queue = 1; |
1519 | } elsif ($arg eq "l") { |
1520 | $debug_lineno = 1; |
1521 | } elsif ($arg eq "t") { |
1522 | $debug_timings = 1; |
1523 | } |
1524 | } |
1525 | } |
1526 | } |
1527 | init_sections(); |
1528 | $init = B::Section->get("init"); |
1529 | $decl = B::Section->get("decl"); |
1530 | |
1531 | if (@options) { |
1532 | return sub { |
1533 | my ($objname, $ppname); |
1534 | foreach $objname (@options) { |
1535 | $objname = "main::$objname" unless $objname =~ /::/; |
1536 | ($ppname = $objname) =~ s/^.*?:://; |
1537 | eval "cc_obj(qq(pp_sub_$ppname), \\&$objname)"; |
1538 | die "cc_obj(qq(pp_sub_$ppname, \\&$objname) failed: $@" if $@; |
1539 | return if $errors; |
1540 | } |
1541 | output_boilerplate(); |
1542 | print "\n"; |
1543 | output_all($module_name || "init_module"); |
1544 | output_runtime(); |
1545 | } |
1546 | } else { |
1547 | return sub { cc_main() }; |
1548 | } |
1549 | } |
1550 | |
1551 | 1; |
7f20e9dd |
1552 | |
1553 | __END__ |
1554 | |
1555 | =head1 NAME |
1556 | |
1557 | B::CC - Perl compiler's optimized C translation backend |
1558 | |
1559 | =head1 SYNOPSIS |
1560 | |
1561 | perl -MO=CC[,OPTIONS] foo.pl |
1562 | |
1563 | =head1 DESCRIPTION |
1564 | |
1a52ab62 |
1565 | This compiler backend takes Perl source and generates C source code |
1566 | corresponding to the flow of your program. In other words, this |
1567 | backend is somewhat a "real" compiler in the sense that many people |
1568 | think about compilers. Note however that, currently, it is a very |
1569 | poor compiler in that although it generates (mostly, or at least |
1570 | sometimes) correct code, it performs relatively few optimisations. |
1571 | This will change as the compiler develops. The result is that |
1572 | running an executable compiled with this backend may start up more |
1573 | quickly than running the original Perl program (a feature shared |
1574 | by the B<C> compiler backend--see F<B::C>) and may also execute |
1575 | slightly faster. This is by no means a good optimising compiler--yet. |
1576 | |
1577 | =head1 OPTIONS |
1578 | |
1579 | If there are any non-option arguments, they are taken to be |
1580 | names of objects to be saved (probably doesn't work properly yet). |
1581 | Without extra arguments, it saves the main program. |
1582 | |
1583 | =over 4 |
1584 | |
1585 | =item B<-ofilename> |
1586 | |
1587 | Output to filename instead of STDOUT |
1588 | |
1589 | =item B<-v> |
1590 | |
1591 | Verbose compilation (currently gives a few compilation statistics). |
1592 | |
1593 | =item B<--> |
1594 | |
1595 | Force end of options |
1596 | |
1597 | =item B<-uPackname> |
1598 | |
1599 | Force apparently unused subs from package Packname to be compiled. |
1600 | This allows programs to use eval "foo()" even when sub foo is never |
1601 | seen to be used at compile time. The down side is that any subs which |
1602 | really are never used also have code generated. This option is |
1603 | necessary, for example, if you have a signal handler foo which you |
1604 | initialise with C<$SIG{BAR} = "foo">. A better fix, though, is just |
1605 | to change it to C<$SIG{BAR} = \&foo>. You can have multiple B<-u> |
1606 | options. The compiler tries to figure out which packages may possibly |
1607 | have subs in which need compiling but the current version doesn't do |
1608 | it very well. In particular, it is confused by nested packages (i.e. |
1609 | of the form C<A::B>) where package C<A> does not contain any subs. |
1610 | |
1611 | =item B<-mModulename> |
1612 | |
1613 | Instead of generating source for a runnable executable, generate |
1614 | source for an XSUB module. The boot_Modulename function (which |
1615 | DynaLoader can look for) does the appropriate initialisation and runs |
1616 | the main part of the Perl source that is being compiled. |
1617 | |
1618 | |
1619 | =item B<-D> |
1620 | |
1621 | Debug options (concatenated or separate flags like C<perl -D>). |
1622 | |
1623 | =item B<-Dr> |
1624 | |
1625 | Writes debugging output to STDERR just as it's about to write to the |
1626 | program's runtime (otherwise writes debugging info as comments in |
1627 | its C output). |
1628 | |
1629 | =item B<-DO> |
1630 | |
1631 | Outputs each OP as it's compiled |
1632 | |
1633 | =item B<-Ds> |
1634 | |
1635 | Outputs the contents of the shadow stack at each OP |
1636 | |
1637 | =item B<-Dp> |
1638 | |
1639 | Outputs the contents of the shadow pad of lexicals as it's loaded for |
1640 | each sub or the main program. |
1641 | |
1642 | =item B<-Dq> |
1643 | |
1644 | Outputs the name of each fake PP function in the queue as it's about |
1645 | to process it. |
1646 | |
1647 | =item B<-Dl> |
1648 | |
1649 | Output the filename and line number of each original line of Perl |
1650 | code as it's processed (C<pp_nextstate>). |
1651 | |
1652 | =item B<-Dt> |
1653 | |
1654 | Outputs timing information of compilation stages. |
1655 | |
1656 | =item B<-f> |
1657 | |
1658 | Force optimisations on or off one at a time. |
1659 | |
1660 | =item B<-ffreetmps-each-bblock> |
1661 | |
1662 | Delays FREETMPS from the end of each statement to the end of the each |
1663 | basic block. |
1664 | |
1665 | =item B<-ffreetmps-each-loop> |
1666 | |
1667 | Delays FREETMPS from the end of each statement to the end of the group |
1668 | of basic blocks forming a loop. At most one of the freetmps-each-* |
1669 | options can be used. |
1670 | |
1671 | =item B<-fomit-taint> |
1672 | |
1673 | Omits generating code for handling perl's tainting mechanism. |
1674 | |
1675 | =item B<-On> |
1676 | |
1677 | Optimisation level (n = 0, 1, 2, ...). B<-O> means B<-O1>. |
1678 | Currently, B<-O1> sets B<-ffreetmps-each-bblock> and B<-O2> |
1679 | sets B<-ffreetmps-each-loop>. |
1680 | |
1681 | =back |
1682 | |
1683 | =head1 EXAMPLES |
1684 | |
1685 | perl -MO=CC,-O2,-ofoo.c foo.pl |
1686 | perl cc_harness -o foo foo.c |
1687 | |
1688 | Note that C<cc_harness> lives in the C<B> subdirectory of your perl |
1689 | library directory. The utility called C<perlcc> may also be used to |
1690 | help make use of this compiler. |
1691 | |
1692 | perl -MO=CC,-mFoo,-oFoo.c Foo.pm |
1693 | perl cc_harness -shared -c -o Foo.so Foo.c |
1694 | |
1695 | =head1 BUGS |
1696 | |
1697 | Plenty. Current status: experimental. |
1698 | |
1699 | =head1 DIFFERENCES |
1700 | |
1701 | These aren't really bugs but they are constructs which are heavily |
1702 | tied to perl's compile-and-go implementation and with which this |
1703 | compiler backend cannot cope. |
1704 | |
1705 | =head2 Loops |
1706 | |
1707 | Standard perl calculates the target of "next", "last", and "redo" |
1708 | at run-time. The compiler calculates the targets at compile-time. |
1709 | For example, the program |
1710 | |
1711 | sub skip_on_odd { next NUMBER if $_[0] % 2 } |
1712 | NUMBER: for ($i = 0; $i < 5; $i++) { |
1713 | skip_on_odd($i); |
1714 | print $i; |
1715 | } |
1716 | |
1717 | produces the output |
1718 | |
1719 | 024 |
1720 | |
1721 | with standard perl but gives a compile-time error with the compiler. |
1722 | |
1723 | =head2 Context of ".." |
1724 | |
1725 | The context (scalar or array) of the ".." operator determines whether |
1726 | it behaves as a range or a flip/flop. Standard perl delays until |
1727 | runtime the decision of which context it is in but the compiler needs |
1728 | to know the context at compile-time. For example, |
1729 | |
1730 | @a = (4,6,1,0,0,1); |
1731 | sub range { (shift @a)..(shift @a) } |
1732 | print range(); |
1733 | while (@a) { print scalar(range()) } |
1734 | |
1735 | generates the output |
1736 | |
1737 | 456123E0 |
1738 | |
1739 | with standard Perl but gives a compile-time error with compiled Perl. |
1740 | |
1741 | =head2 Arithmetic |
1742 | |
1743 | Compiled Perl programs use native C arithemtic much more frequently |
1744 | than standard perl. Operations on large numbers or on boundary |
1745 | cases may produce different behaviour. |
1746 | |
1747 | =head2 Deprecated features |
1748 | |
1749 | Features of standard perl such as C<$[> which have been deprecated |
1750 | in standard perl since Perl5 was released have not been implemented |
1751 | in the compiler. |
7f20e9dd |
1752 | |
1753 | =head1 AUTHOR |
1754 | |
1755 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
1756 | |
1757 | =cut |