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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; |
2e51e4c9 |
353 | while ($cxix >= 0 && |
354 | ($cxstack[$cxix]->{type} != CXt_LOOP || |
355 | $cxstack[$cxix]->{label} ne $label)) { |
a798dbf2 |
356 | $cxix--; |
357 | } |
358 | debug "dopoptolabel: returning $cxix" if $debug_cxstack; |
359 | return $cxix; |
360 | } |
361 | |
362 | sub error { |
363 | my $format = shift; |
364 | my $file = $curcop->[0]->filegv->SV->PV; |
365 | my $line = $curcop->[0]->line; |
366 | $errors++; |
367 | if (@_) { |
368 | warn sprintf("%s:%d: $format\n", $file, $line, @_); |
369 | } else { |
370 | warn sprintf("%s:%d: %s\n", $file, $line, $format); |
371 | } |
372 | } |
373 | |
374 | # |
375 | # Load pad takes (the elements of) a PADLIST as arguments and loads |
376 | # up @pad with Stackobj-derived objects which represent those lexicals. |
377 | # If/when perl itself can generate type information (my int $foo) then |
378 | # we'll take advantage of that here. Until then, we'll use various hacks |
379 | # to tell the compiler when we want a lexical to be a particular type |
380 | # or to be a register. |
381 | # |
382 | sub load_pad { |
383 | my ($namelistav, $valuelistav) = @_; |
384 | @padlist = @_; |
385 | my @namelist = $namelistav->ARRAY; |
386 | my @valuelist = $valuelistav->ARRAY; |
387 | my $ix; |
388 | @pad = (); |
389 | debug "load_pad: $#namelist names, $#valuelist values\n" if $debug_pad; |
390 | # Temporary lexicals don't get named so it's possible for @valuelist |
391 | # to be strictly longer than @namelist. We count $ix up to the end of |
392 | # @valuelist but index into @namelist for the name. Any temporaries which |
393 | # run off the end of @namelist will make $namesv undefined and we treat |
394 | # that the same as having an explicit SPECIAL sv_undef object in @namelist. |
395 | # [XXX If/when @_ becomes a lexical, we must start at 0 here.] |
396 | for ($ix = 1; $ix < @valuelist; $ix++) { |
397 | my $namesv = $namelist[$ix]; |
398 | my $type = T_UNKNOWN; |
399 | my $flags = 0; |
400 | my $name = "tmp$ix"; |
401 | my $class = class($namesv); |
402 | if (!defined($namesv) || $class eq "SPECIAL") { |
81009501 |
403 | # temporaries have &PL_sv_undef instead of a PVNV for a name |
a798dbf2 |
404 | $flags = VALID_SV|TEMPORARY|REGISTER; |
405 | } else { |
406 | if ($namesv->PV =~ /^\$(.*)_([di])(r?)$/) { |
407 | $name = $1; |
408 | if ($2 eq "i") { |
409 | $type = T_INT; |
410 | $flags = VALID_SV|VALID_INT; |
411 | } elsif ($2 eq "d") { |
412 | $type = T_DOUBLE; |
413 | $flags = VALID_SV|VALID_DOUBLE; |
414 | } |
415 | $flags |= REGISTER if $3; |
416 | } |
417 | } |
418 | $pad[$ix] = new B::Stackobj::Padsv ($type, $flags, $ix, |
419 | "i_$name", "d_$name"); |
420 | declare("IV", $type == T_INT ? "i_$name = 0" : "i_$name"); |
421 | declare("double", $type == T_DOUBLE ? "d_$name = 0" : "d_$name"); |
81009501 |
422 | debug sprintf("PL_curpad[$ix] = %s\n", $pad[$ix]->peek) if $debug_pad; |
a798dbf2 |
423 | } |
424 | } |
425 | |
426 | # |
427 | # Debugging stuff |
428 | # |
429 | sub peek_stack { sprintf "stack = %s\n", join(" ", map($_->minipeek, @stack)) } |
430 | |
431 | # |
432 | # OP stuff |
433 | # |
434 | |
435 | sub label { |
436 | my $op = shift; |
437 | # XXX Preserve original label name for "real" labels? |
438 | return sprintf("lab_%x", $$op); |
439 | } |
440 | |
441 | sub write_label { |
442 | my $op = shift; |
443 | push_runtime(sprintf(" %s:", label($op))); |
444 | } |
445 | |
446 | sub loadop { |
447 | my $op = shift; |
448 | my $opsym = $op->save; |
81009501 |
449 | runtime("PL_op = $opsym;") unless $know_op; |
a798dbf2 |
450 | return $opsym; |
451 | } |
452 | |
453 | sub doop { |
454 | my $op = shift; |
455 | my $ppname = $op->ppaddr; |
456 | my $sym = loadop($op); |
457 | runtime("DOOP($ppname);"); |
458 | $know_op = 1; |
459 | return $sym; |
460 | } |
461 | |
462 | sub gimme { |
463 | my $op = shift; |
464 | my $flags = $op->flags; |
465 | return (($flags & OPf_KNOW) ? ($flags & OPf_LIST) : "dowantarray()"); |
466 | } |
467 | |
468 | # |
469 | # Code generation for PP code |
470 | # |
471 | |
472 | sub pp_null { |
473 | my $op = shift; |
474 | return $op->next; |
475 | } |
476 | |
477 | sub pp_stub { |
478 | my $op = shift; |
479 | my $gimme = gimme($op); |
480 | if ($gimme != 1) { |
481 | # XXX Change to push a constant sv_undef Stackobj onto @stack |
482 | write_back_stack(); |
81009501 |
483 | runtime("if ($gimme != G_ARRAY) XPUSHs(&PL_sv_undef);"); |
a798dbf2 |
484 | } |
485 | return $op->next; |
486 | } |
487 | |
488 | sub pp_unstack { |
489 | my $op = shift; |
490 | @stack = (); |
491 | runtime("PP_UNSTACK;"); |
492 | return $op->next; |
493 | } |
494 | |
495 | sub pp_and { |
496 | my $op = shift; |
497 | my $next = $op->next; |
498 | reload_lexicals(); |
499 | unshift(@bblock_todo, $next); |
500 | if (@stack >= 1) { |
501 | my $bool = pop_bool(); |
502 | write_back_stack(); |
44887cfa |
503 | runtime(sprintf("if (!$bool) {XPUSHs(&PL_sv_no); goto %s;}", label($next))); |
a798dbf2 |
504 | } else { |
505 | runtime(sprintf("if (!%s) goto %s;", top_bool(), label($next)), |
506 | "*sp--;"); |
507 | } |
508 | return $op->other; |
509 | } |
510 | |
511 | sub pp_or { |
512 | my $op = shift; |
513 | my $next = $op->next; |
514 | reload_lexicals(); |
515 | unshift(@bblock_todo, $next); |
516 | if (@stack >= 1) { |
44887cfa |
517 | my $bool = pop_bool @stack; |
a798dbf2 |
518 | write_back_stack(); |
44887cfa |
519 | runtime(sprintf("if (%s) { XPUSHs(&PL_sv_yes); goto %s; }", |
520 | $bool, label($next))); |
a798dbf2 |
521 | } else { |
522 | runtime(sprintf("if (%s) goto %s;", top_bool(), label($next)), |
523 | "*sp--;"); |
524 | } |
525 | return $op->other; |
526 | } |
527 | |
528 | sub pp_cond_expr { |
529 | my $op = shift; |
530 | my $false = $op->false; |
531 | unshift(@bblock_todo, $false); |
532 | reload_lexicals(); |
533 | my $bool = pop_bool(); |
534 | write_back_stack(); |
535 | runtime(sprintf("if (!$bool) goto %s;", label($false))); |
536 | return $op->true; |
537 | } |
538 | |
539 | sub pp_padsv { |
540 | my $op = shift; |
541 | my $ix = $op->targ; |
542 | push(@stack, $pad[$ix]); |
543 | if ($op->flags & OPf_MOD) { |
544 | my $private = $op->private; |
545 | if ($private & OPpLVAL_INTRO) { |
81009501 |
546 | runtime("SAVECLEARSV(PL_curpad[$ix]);"); |
a798dbf2 |
547 | } elsif ($private & OPpDEREF) { |
81009501 |
548 | runtime(sprintf("vivify_ref(PL_curpad[%d], %d);", |
a798dbf2 |
549 | $ix, $private & OPpDEREF)); |
550 | $pad[$ix]->invalidate; |
551 | } |
552 | } |
553 | return $op->next; |
554 | } |
555 | |
556 | sub pp_const { |
557 | my $op = shift; |
558 | my $sv = $op->sv; |
559 | my $obj = $constobj{$$sv}; |
560 | if (!defined($obj)) { |
561 | $obj = $constobj{$$sv} = new B::Stackobj::Const ($sv); |
562 | } |
563 | push(@stack, $obj); |
564 | return $op->next; |
565 | } |
566 | |
567 | sub pp_nextstate { |
568 | my $op = shift; |
569 | $curcop->load($op); |
570 | @stack = (); |
571 | debug(sprintf("%s:%d\n", $op->filegv->SV->PV, $op->line)) if $debug_lineno; |
572 | runtime("TAINT_NOT;") unless $omit_taint; |
81009501 |
573 | runtime("sp = PL_stack_base + cxstack[cxstack_ix].blk_oldsp;"); |
a798dbf2 |
574 | if ($freetmps_each_bblock || $freetmps_each_loop) { |
575 | $need_freetmps = 1; |
576 | } else { |
577 | runtime("FREETMPS;"); |
578 | } |
579 | return $op->next; |
580 | } |
581 | |
582 | sub pp_dbstate { |
583 | my $op = shift; |
584 | $curcop->invalidate; # XXX? |
585 | return default_pp($op); |
586 | } |
587 | |
588 | sub pp_rv2gv { $curcop->write_back; default_pp(@_) } |
589 | sub pp_bless { $curcop->write_back; default_pp(@_) } |
590 | sub pp_repeat { $curcop->write_back; default_pp(@_) } |
591 | # The following subs need $curcop->write_back if we decide to support arybase: |
592 | # pp_pos, pp_substr, pp_index, pp_rindex, pp_aslice, pp_lslice, pp_splice |
593 | sub pp_sort { $curcop->write_back; default_pp(@_) } |
594 | sub pp_caller { $curcop->write_back; default_pp(@_) } |
595 | sub pp_reset { $curcop->write_back; default_pp(@_) } |
596 | |
597 | sub pp_gv { |
598 | my $op = shift; |
599 | my $gvsym = $op->gv->save; |
600 | write_back_stack(); |
601 | runtime("XPUSHs((SV*)$gvsym);"); |
602 | return $op->next; |
603 | } |
604 | |
605 | sub pp_gvsv { |
606 | my $op = shift; |
607 | my $gvsym = $op->gv->save; |
608 | write_back_stack(); |
609 | if ($op->private & OPpLVAL_INTRO) { |
610 | runtime("XPUSHs(save_scalar($gvsym));"); |
611 | } else { |
612 | runtime("XPUSHs(GvSV($gvsym));"); |
613 | } |
614 | return $op->next; |
615 | } |
616 | |
617 | sub pp_aelemfast { |
618 | my $op = shift; |
619 | my $gvsym = $op->gv->save; |
620 | my $ix = $op->private; |
621 | my $flag = $op->flags & OPf_MOD; |
622 | write_back_stack(); |
623 | runtime("svp = av_fetch(GvAV($gvsym), $ix, $flag);", |
81009501 |
624 | "PUSHs(svp ? *svp : &PL_sv_undef);"); |
a798dbf2 |
625 | return $op->next; |
626 | } |
627 | |
628 | sub int_binop { |
629 | my ($op, $operator) = @_; |
630 | if ($op->flags & OPf_STACKED) { |
631 | my $right = pop_int(); |
632 | if (@stack >= 1) { |
633 | my $left = top_int(); |
634 | $stack[-1]->set_int(&$operator($left, $right)); |
635 | } else { |
636 | runtime(sprintf("sv_setiv(TOPs, %s);",&$operator("TOPi", $right))); |
637 | } |
638 | } else { |
639 | my $targ = $pad[$op->targ]; |
640 | my $right = new B::Pseudoreg ("IV", "riv"); |
641 | my $left = new B::Pseudoreg ("IV", "liv"); |
642 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int)); |
643 | $targ->set_int(&$operator($$left, $$right)); |
644 | push(@stack, $targ); |
645 | } |
646 | return $op->next; |
647 | } |
648 | |
649 | sub INTS_CLOSED () { 0x1 } |
650 | sub INT_RESULT () { 0x2 } |
651 | sub NUMERIC_RESULT () { 0x4 } |
652 | |
653 | sub numeric_binop { |
654 | my ($op, $operator, $flags) = @_; |
655 | my $force_int = 0; |
656 | $force_int ||= ($flags & INT_RESULT); |
657 | $force_int ||= ($flags & INTS_CLOSED && @stack >= 2 |
658 | && valid_int($stack[-2]) && valid_int($stack[-1])); |
659 | if ($op->flags & OPf_STACKED) { |
660 | my $right = pop_numeric(); |
661 | if (@stack >= 1) { |
662 | my $left = top_numeric(); |
663 | if ($force_int) { |
664 | $stack[-1]->set_int(&$operator($left, $right)); |
665 | } else { |
666 | $stack[-1]->set_numeric(&$operator($left, $right)); |
667 | } |
668 | } else { |
669 | if ($force_int) { |
670 | runtime(sprintf("sv_setiv(TOPs, %s);", |
671 | &$operator("TOPi", $right))); |
672 | } else { |
673 | runtime(sprintf("sv_setnv(TOPs, %s);", |
674 | &$operator("TOPn", $right))); |
675 | } |
676 | } |
677 | } else { |
678 | my $targ = $pad[$op->targ]; |
679 | $force_int ||= ($targ->{type} == T_INT); |
680 | if ($force_int) { |
681 | my $right = new B::Pseudoreg ("IV", "riv"); |
682 | my $left = new B::Pseudoreg ("IV", "liv"); |
683 | runtime(sprintf("$$right = %s; $$left = %s;", |
684 | pop_numeric(), pop_numeric)); |
685 | $targ->set_int(&$operator($$left, $$right)); |
686 | } else { |
687 | my $right = new B::Pseudoreg ("double", "rnv"); |
688 | my $left = new B::Pseudoreg ("double", "lnv"); |
689 | runtime(sprintf("$$right = %s; $$left = %s;", |
690 | pop_numeric(), pop_numeric)); |
691 | $targ->set_numeric(&$operator($$left, $$right)); |
692 | } |
693 | push(@stack, $targ); |
694 | } |
695 | return $op->next; |
696 | } |
697 | |
698 | sub sv_binop { |
699 | my ($op, $operator, $flags) = @_; |
700 | if ($op->flags & OPf_STACKED) { |
701 | my $right = pop_sv(); |
702 | if (@stack >= 1) { |
703 | my $left = top_sv(); |
704 | if ($flags & INT_RESULT) { |
705 | $stack[-1]->set_int(&$operator($left, $right)); |
706 | } elsif ($flags & NUMERIC_RESULT) { |
707 | $stack[-1]->set_numeric(&$operator($left, $right)); |
708 | } else { |
709 | # XXX Does this work? |
710 | runtime(sprintf("sv_setsv($left, %s);", |
711 | &$operator($left, $right))); |
712 | $stack[-1]->invalidate; |
713 | } |
714 | } else { |
715 | my $f; |
716 | if ($flags & INT_RESULT) { |
717 | $f = "sv_setiv"; |
718 | } elsif ($flags & NUMERIC_RESULT) { |
719 | $f = "sv_setnv"; |
720 | } else { |
721 | $f = "sv_setsv"; |
722 | } |
723 | runtime(sprintf("%s(TOPs, %s);", $f, &$operator("TOPs", $right))); |
724 | } |
725 | } else { |
726 | my $targ = $pad[$op->targ]; |
727 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv)); |
728 | if ($flags & INT_RESULT) { |
729 | $targ->set_int(&$operator("left", "right")); |
730 | } elsif ($flags & NUMERIC_RESULT) { |
731 | $targ->set_numeric(&$operator("left", "right")); |
732 | } else { |
733 | # XXX Does this work? |
734 | runtime(sprintf("sv_setsv(%s, %s);", |
735 | $targ->as_sv, &$operator("left", "right"))); |
736 | $targ->invalidate; |
737 | } |
738 | push(@stack, $targ); |
739 | } |
740 | return $op->next; |
741 | } |
742 | |
743 | sub bool_int_binop { |
744 | my ($op, $operator) = @_; |
745 | my $right = new B::Pseudoreg ("IV", "riv"); |
746 | my $left = new B::Pseudoreg ("IV", "liv"); |
747 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int())); |
748 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
749 | $bool->set_int(&$operator($$left, $$right)); |
750 | push(@stack, $bool); |
751 | return $op->next; |
752 | } |
753 | |
754 | sub bool_numeric_binop { |
755 | my ($op, $operator) = @_; |
756 | my $right = new B::Pseudoreg ("double", "rnv"); |
757 | my $left = new B::Pseudoreg ("double", "lnv"); |
758 | runtime(sprintf("$$right = %s; $$left = %s;", |
759 | pop_numeric(), pop_numeric())); |
760 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
761 | $bool->set_numeric(&$operator($$left, $$right)); |
762 | push(@stack, $bool); |
763 | return $op->next; |
764 | } |
765 | |
766 | sub bool_sv_binop { |
767 | my ($op, $operator) = @_; |
768 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv())); |
769 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
770 | $bool->set_numeric(&$operator("left", "right")); |
771 | push(@stack, $bool); |
772 | return $op->next; |
773 | } |
774 | |
775 | sub infix_op { |
776 | my $opname = shift; |
777 | return sub { "$_[0] $opname $_[1]" } |
778 | } |
779 | |
780 | sub prefix_op { |
781 | my $opname = shift; |
782 | return sub { sprintf("%s(%s)", $opname, join(", ", @_)) } |
783 | } |
784 | |
785 | BEGIN { |
786 | my $plus_op = infix_op("+"); |
787 | my $minus_op = infix_op("-"); |
788 | my $multiply_op = infix_op("*"); |
789 | my $divide_op = infix_op("/"); |
790 | my $modulo_op = infix_op("%"); |
791 | my $lshift_op = infix_op("<<"); |
a0d31f98 |
792 | my $rshift_op = infix_op(">>"); |
a798dbf2 |
793 | my $ncmp_op = sub { "($_[0] > $_[1] ? 1 : ($_[0] < $_[1]) ? -1 : 0)" }; |
794 | my $scmp_op = prefix_op("sv_cmp"); |
795 | my $seq_op = prefix_op("sv_eq"); |
796 | my $sne_op = prefix_op("!sv_eq"); |
797 | my $slt_op = sub { "sv_cmp($_[0], $_[1]) < 0" }; |
798 | my $sgt_op = sub { "sv_cmp($_[0], $_[1]) > 0" }; |
799 | my $sle_op = sub { "sv_cmp($_[0], $_[1]) <= 0" }; |
800 | my $sge_op = sub { "sv_cmp($_[0], $_[1]) >= 0" }; |
801 | my $eq_op = infix_op("=="); |
802 | my $ne_op = infix_op("!="); |
803 | my $lt_op = infix_op("<"); |
804 | my $gt_op = infix_op(">"); |
805 | my $le_op = infix_op("<="); |
806 | my $ge_op = infix_op(">="); |
807 | |
808 | # |
809 | # XXX The standard perl PP code has extra handling for |
810 | # some special case arguments of these operators. |
811 | # |
812 | sub pp_add { numeric_binop($_[0], $plus_op, INTS_CLOSED) } |
813 | sub pp_subtract { numeric_binop($_[0], $minus_op, INTS_CLOSED) } |
814 | sub pp_multiply { numeric_binop($_[0], $multiply_op, INTS_CLOSED) } |
815 | sub pp_divide { numeric_binop($_[0], $divide_op) } |
816 | sub pp_modulo { int_binop($_[0], $modulo_op) } # differs from perl's |
817 | sub pp_ncmp { numeric_binop($_[0], $ncmp_op, INT_RESULT) } |
818 | |
819 | sub pp_left_shift { int_binop($_[0], $lshift_op) } |
820 | sub pp_right_shift { int_binop($_[0], $rshift_op) } |
821 | sub pp_i_add { int_binop($_[0], $plus_op) } |
822 | sub pp_i_subtract { int_binop($_[0], $minus_op) } |
823 | sub pp_i_multiply { int_binop($_[0], $multiply_op) } |
824 | sub pp_i_divide { int_binop($_[0], $divide_op) } |
825 | sub pp_i_modulo { int_binop($_[0], $modulo_op) } |
826 | |
827 | sub pp_eq { bool_numeric_binop($_[0], $eq_op) } |
828 | sub pp_ne { bool_numeric_binop($_[0], $ne_op) } |
829 | sub pp_lt { bool_numeric_binop($_[0], $lt_op) } |
830 | sub pp_gt { bool_numeric_binop($_[0], $gt_op) } |
831 | sub pp_le { bool_numeric_binop($_[0], $le_op) } |
832 | sub pp_ge { bool_numeric_binop($_[0], $ge_op) } |
833 | |
834 | sub pp_i_eq { bool_int_binop($_[0], $eq_op) } |
835 | sub pp_i_ne { bool_int_binop($_[0], $ne_op) } |
836 | sub pp_i_lt { bool_int_binop($_[0], $lt_op) } |
837 | sub pp_i_gt { bool_int_binop($_[0], $gt_op) } |
838 | sub pp_i_le { bool_int_binop($_[0], $le_op) } |
839 | sub pp_i_ge { bool_int_binop($_[0], $ge_op) } |
840 | |
841 | sub pp_scmp { sv_binop($_[0], $scmp_op, INT_RESULT) } |
842 | sub pp_slt { bool_sv_binop($_[0], $slt_op) } |
843 | sub pp_sgt { bool_sv_binop($_[0], $sgt_op) } |
844 | sub pp_sle { bool_sv_binop($_[0], $sle_op) } |
845 | sub pp_sge { bool_sv_binop($_[0], $sge_op) } |
846 | sub pp_seq { bool_sv_binop($_[0], $seq_op) } |
847 | sub pp_sne { bool_sv_binop($_[0], $sne_op) } |
848 | } |
849 | |
850 | |
851 | sub pp_sassign { |
852 | my $op = shift; |
853 | my $backwards = $op->private & OPpASSIGN_BACKWARDS; |
854 | my ($dst, $src); |
855 | if (@stack >= 2) { |
856 | $dst = pop @stack; |
857 | $src = pop @stack; |
858 | ($src, $dst) = ($dst, $src) if $backwards; |
859 | my $type = $src->{type}; |
860 | if ($type == T_INT) { |
861 | $dst->set_int($src->as_int); |
862 | } elsif ($type == T_DOUBLE) { |
863 | $dst->set_numeric($src->as_numeric); |
864 | } else { |
865 | $dst->set_sv($src->as_sv); |
866 | } |
867 | push(@stack, $dst); |
868 | } elsif (@stack == 1) { |
869 | if ($backwards) { |
870 | my $src = pop @stack; |
871 | my $type = $src->{type}; |
81009501 |
872 | runtime("if (PL_tainting && PL_tainted) TAINT_NOT;"); |
a798dbf2 |
873 | if ($type == T_INT) { |
874 | runtime sprintf("sv_setiv(TOPs, %s);", $src->as_int); |
875 | } elsif ($type == T_DOUBLE) { |
876 | runtime sprintf("sv_setnv(TOPs, %s);", $src->as_double); |
877 | } else { |
878 | runtime sprintf("sv_setsv(TOPs, %s);", $src->as_sv); |
879 | } |
880 | runtime("SvSETMAGIC(TOPs);"); |
881 | } else { |
b8f1fa48 |
882 | my $dst = $stack[-1]; |
a798dbf2 |
883 | my $type = $dst->{type}; |
884 | runtime("sv = POPs;"); |
885 | runtime("MAYBE_TAINT_SASSIGN_SRC(sv);"); |
886 | if ($type == T_INT) { |
887 | $dst->set_int("SvIV(sv)"); |
888 | } elsif ($type == T_DOUBLE) { |
889 | $dst->set_double("SvNV(sv)"); |
890 | } else { |
891 | runtime("SvSetSV($dst->{sv}, sv);"); |
892 | $dst->invalidate; |
893 | } |
894 | } |
895 | } else { |
896 | if ($backwards) { |
897 | runtime("src = POPs; dst = TOPs;"); |
898 | } else { |
899 | runtime("dst = POPs; src = TOPs;"); |
900 | } |
901 | runtime("MAYBE_TAINT_SASSIGN_SRC(src);", |
902 | "SvSetSV(dst, src);", |
903 | "SvSETMAGIC(dst);", |
904 | "SETs(dst);"); |
905 | } |
906 | return $op->next; |
907 | } |
908 | |
909 | sub pp_preinc { |
910 | my $op = shift; |
911 | if (@stack >= 1) { |
912 | my $obj = $stack[-1]; |
913 | my $type = $obj->{type}; |
914 | if ($type == T_INT || $type == T_DOUBLE) { |
915 | $obj->set_int($obj->as_int . " + 1"); |
916 | } else { |
917 | runtime sprintf("PP_PREINC(%s);", $obj->as_sv); |
918 | $obj->invalidate(); |
919 | } |
920 | } else { |
921 | runtime sprintf("PP_PREINC(TOPs);"); |
922 | } |
923 | return $op->next; |
924 | } |
925 | |
926 | sub pp_pushmark { |
927 | my $op = shift; |
928 | write_back_stack(); |
929 | runtime("PUSHMARK(sp);"); |
930 | return $op->next; |
931 | } |
932 | |
933 | sub pp_list { |
934 | my $op = shift; |
935 | write_back_stack(); |
936 | my $gimme = gimme($op); |
937 | if ($gimme == 1) { # sic |
938 | runtime("POPMARK;"); # need this even though not a "full" pp_list |
939 | } else { |
940 | runtime("PP_LIST($gimme);"); |
941 | } |
942 | return $op->next; |
943 | } |
944 | |
945 | sub pp_entersub { |
946 | my $op = shift; |
947 | write_back_lexicals(REGISTER|TEMPORARY); |
948 | write_back_stack(); |
949 | my $sym = doop($op); |
5cfd8ad4 |
950 | runtime("while (PL_op != ($sym)->op_next && PL_op != (OP*)0 ){"); |
951 | runtime("PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
952 | runtime("SPAGAIN;}"); |
a798dbf2 |
953 | $know_op = 0; |
954 | invalidate_lexicals(REGISTER|TEMPORARY); |
955 | return $op->next; |
956 | } |
957 | |
5cfd8ad4 |
958 | sub pp_goto{ |
959 | |
960 | my $op = shift; |
961 | my $ppname = $op->ppaddr; |
962 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
963 | write_back_stack() unless $skip_stack{$ppname}; |
964 | my $sym=doop($op); |
965 | runtime("if (PL_op != ($sym)->op_next && PL_op != (OP*)0){return PL_op;}"); |
966 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
967 | return $op->next; |
968 | } |
a798dbf2 |
969 | sub pp_enterwrite { |
970 | my $op = shift; |
971 | pp_entersub($op); |
972 | } |
973 | |
974 | sub pp_leavewrite { |
975 | my $op = shift; |
976 | write_back_lexicals(REGISTER|TEMPORARY); |
977 | write_back_stack(); |
978 | my $sym = doop($op); |
979 | # XXX Is this the right way to distinguish between it returning |
980 | # CvSTART(cv) (via doform) and pop_return()? |
81009501 |
981 | runtime("if (PL_op) PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
a798dbf2 |
982 | runtime("SPAGAIN;"); |
983 | $know_op = 0; |
984 | invalidate_lexicals(REGISTER|TEMPORARY); |
985 | return $op->next; |
986 | } |
987 | |
988 | sub doeval { |
989 | my $op = shift; |
990 | $curcop->write_back; |
991 | write_back_lexicals(REGISTER|TEMPORARY); |
992 | write_back_stack(); |
993 | my $sym = loadop($op); |
994 | my $ppaddr = $op->ppaddr; |
995 | runtime("PP_EVAL($ppaddr, ($sym)->op_next);"); |
996 | $know_op = 1; |
997 | invalidate_lexicals(REGISTER|TEMPORARY); |
998 | return $op->next; |
999 | } |
1000 | |
1001 | sub pp_entereval { doeval(@_) } |
1002 | sub pp_require { doeval(@_) } |
1003 | sub pp_dofile { doeval(@_) } |
1004 | |
1005 | sub pp_entertry { |
1006 | my $op = shift; |
1007 | $curcop->write_back; |
1008 | write_back_lexicals(REGISTER|TEMPORARY); |
1009 | write_back_stack(); |
1010 | my $sym = doop($op); |
1011 | my $jmpbuf = sprintf("jmpbuf%d", $jmpbuf_ix++); |
1012 | declare("Sigjmp_buf", $jmpbuf); |
1013 | runtime(sprintf("PP_ENTERTRY(%s,%s);", $jmpbuf, label($op->other->next))); |
1014 | invalidate_lexicals(REGISTER|TEMPORARY); |
1015 | return $op->next; |
1016 | } |
1017 | |
1018 | sub pp_grepstart { |
1019 | my $op = shift; |
1020 | if ($need_freetmps && $freetmps_each_loop) { |
1021 | runtime("FREETMPS;"); # otherwise the grepwhile loop messes things up |
1022 | $need_freetmps = 0; |
1023 | } |
1024 | write_back_stack(); |
1025 | doop($op); |
1026 | return $op->next->other; |
1027 | } |
1028 | |
1029 | sub pp_mapstart { |
1030 | my $op = shift; |
1031 | if ($need_freetmps && $freetmps_each_loop) { |
1032 | runtime("FREETMPS;"); # otherwise the mapwhile loop messes things up |
1033 | $need_freetmps = 0; |
1034 | } |
1035 | write_back_stack(); |
1036 | doop($op); |
1037 | return $op->next->other; |
1038 | } |
1039 | |
1040 | sub pp_grepwhile { |
1041 | my $op = shift; |
1042 | my $next = $op->next; |
1043 | unshift(@bblock_todo, $next); |
1044 | write_back_lexicals(); |
1045 | write_back_stack(); |
1046 | my $sym = doop($op); |
1047 | # pp_grepwhile can return either op_next or op_other and we need to |
1048 | # be able to distinguish the two at runtime. Since it's possible for |
1049 | # both ops to be "inlined", the fields could both be zero. To get |
1050 | # around that, we hack op_next to be our own op (purely because we |
1051 | # know it's a non-NULL pointer and can't be the same as op_other). |
1052 | $init->add("((LOGOP*)$sym)->op_next = $sym;"); |
81009501 |
1053 | runtime(sprintf("if (PL_op == ($sym)->op_next) goto %s;", label($next))); |
a798dbf2 |
1054 | $know_op = 0; |
1055 | return $op->other; |
1056 | } |
1057 | |
1058 | sub pp_mapwhile { |
1059 | pp_grepwhile(@_); |
1060 | } |
1061 | |
1062 | sub pp_return { |
1063 | my $op = shift; |
1064 | write_back_lexicals(REGISTER|TEMPORARY); |
1065 | write_back_stack(); |
1066 | doop($op); |
7de5877e |
1067 | runtime("PUTBACK;", "return (PL_op)?PL_op->op_next:0;"); |
a798dbf2 |
1068 | $know_op = 0; |
1069 | return $op->next; |
1070 | } |
1071 | |
1072 | sub nyi { |
1073 | my $op = shift; |
1074 | warn sprintf("%s not yet implemented properly\n", $op->ppaddr); |
1075 | return default_pp($op); |
1076 | } |
1077 | |
1078 | sub pp_range { |
1079 | my $op = shift; |
1080 | my $flags = $op->flags; |
1081 | if (!($flags & OPf_KNOW)) { |
1082 | error("context of range unknown at compile-time"); |
1083 | } |
1084 | write_back_lexicals(); |
1085 | write_back_stack(); |
1086 | if (!($flags & OPf_LIST)) { |
1087 | # We need to save our UNOP structure since pp_flop uses |
1088 | # it to find and adjust out targ. We don't need it ourselves. |
1089 | $op->save; |
81009501 |
1090 | runtime sprintf("if (SvTRUE(PL_curpad[%d])) goto %s;", |
a798dbf2 |
1091 | $op->targ, label($op->false)); |
1092 | unshift(@bblock_todo, $op->false); |
1093 | } |
1094 | return $op->true; |
1095 | } |
1096 | |
1097 | sub pp_flip { |
1098 | my $op = shift; |
1099 | my $flags = $op->flags; |
1100 | if (!($flags & OPf_KNOW)) { |
1101 | error("context of flip unknown at compile-time"); |
1102 | } |
1103 | if ($flags & OPf_LIST) { |
1104 | return $op->first->false; |
1105 | } |
1106 | write_back_lexicals(); |
1107 | write_back_stack(); |
1108 | # We need to save our UNOP structure since pp_flop uses |
1109 | # it to find and adjust out targ. We don't need it ourselves. |
1110 | $op->save; |
1111 | my $ix = $op->targ; |
1112 | my $rangeix = $op->first->targ; |
1113 | runtime(($op->private & OPpFLIP_LINENUM) ? |
81009501 |
1114 | "if (PL_last_in_gv && SvIV(TOPs) == IoLINES(GvIOp(PL_last_in_gv))) {" |
a798dbf2 |
1115 | : "if (SvTRUE(TOPs)) {"); |
81009501 |
1116 | runtime("\tsv_setiv(PL_curpad[$rangeix], 1);"); |
a798dbf2 |
1117 | if ($op->flags & OPf_SPECIAL) { |
81009501 |
1118 | runtime("sv_setiv(PL_curpad[$ix], 1);"); |
a798dbf2 |
1119 | } else { |
81009501 |
1120 | runtime("\tsv_setiv(PL_curpad[$ix], 0);", |
a798dbf2 |
1121 | "\tsp--;", |
1122 | sprintf("\tgoto %s;", label($op->first->false))); |
1123 | } |
1124 | runtime("}", |
81009501 |
1125 | qq{sv_setpv(PL_curpad[$ix], "");}, |
1126 | "SETs(PL_curpad[$ix]);"); |
a798dbf2 |
1127 | $know_op = 0; |
1128 | return $op->next; |
1129 | } |
1130 | |
1131 | sub pp_flop { |
1132 | my $op = shift; |
1133 | default_pp($op); |
1134 | $know_op = 0; |
1135 | return $op->next; |
1136 | } |
1137 | |
1138 | sub enterloop { |
1139 | my $op = shift; |
1140 | my $nextop = $op->nextop; |
1141 | my $lastop = $op->lastop; |
1142 | my $redoop = $op->redoop; |
1143 | $curcop->write_back; |
1144 | debug "enterloop: pushing on cxstack" if $debug_cxstack; |
1145 | push(@cxstack, { |
1146 | type => CXt_LOOP, |
1147 | op => $op, |
1148 | "label" => $curcop->[0]->label, |
1149 | nextop => $nextop, |
1150 | lastop => $lastop, |
1151 | redoop => $redoop |
1152 | }); |
1153 | $nextop->save; |
1154 | $lastop->save; |
1155 | $redoop->save; |
1156 | return default_pp($op); |
1157 | } |
1158 | |
1159 | sub pp_enterloop { enterloop(@_) } |
1160 | sub pp_enteriter { enterloop(@_) } |
1161 | |
1162 | sub pp_leaveloop { |
1163 | my $op = shift; |
1164 | if (!@cxstack) { |
1165 | die "panic: leaveloop"; |
1166 | } |
1167 | debug "leaveloop: popping from cxstack" if $debug_cxstack; |
1168 | pop(@cxstack); |
1169 | return default_pp($op); |
1170 | } |
1171 | |
1172 | sub pp_next { |
1173 | my $op = shift; |
1174 | my $cxix; |
1175 | if ($op->flags & OPf_SPECIAL) { |
1176 | $cxix = dopoptoloop(); |
1177 | if ($cxix < 0) { |
1178 | error('"next" used outside loop'); |
1179 | return $op->next; # ignore the op |
1180 | } |
1181 | } else { |
1182 | $cxix = dopoptolabel($op->pv); |
1183 | if ($cxix < 0) { |
1184 | error('Label not found at compile time for "next %s"', $op->pv); |
1185 | return $op->next; # ignore the op |
1186 | } |
1187 | } |
1188 | default_pp($op); |
1189 | my $nextop = $cxstack[$cxix]->{nextop}; |
1190 | push(@bblock_todo, $nextop); |
1191 | runtime(sprintf("goto %s;", label($nextop))); |
1192 | return $op->next; |
1193 | } |
1194 | |
1195 | sub pp_redo { |
1196 | my $op = shift; |
1197 | my $cxix; |
1198 | if ($op->flags & OPf_SPECIAL) { |
1199 | $cxix = dopoptoloop(); |
1200 | if ($cxix < 0) { |
1201 | error('"redo" used outside loop'); |
1202 | return $op->next; # ignore the op |
1203 | } |
1204 | } else { |
1205 | $cxix = dopoptolabel($op->pv); |
1206 | if ($cxix < 0) { |
1207 | error('Label not found at compile time for "redo %s"', $op->pv); |
1208 | return $op->next; # ignore the op |
1209 | } |
1210 | } |
1211 | default_pp($op); |
1212 | my $redoop = $cxstack[$cxix]->{redoop}; |
1213 | push(@bblock_todo, $redoop); |
1214 | runtime(sprintf("goto %s;", label($redoop))); |
1215 | return $op->next; |
1216 | } |
1217 | |
1218 | sub pp_last { |
1219 | my $op = shift; |
1220 | my $cxix; |
1221 | if ($op->flags & OPf_SPECIAL) { |
1222 | $cxix = dopoptoloop(); |
1223 | if ($cxix < 0) { |
1224 | error('"last" used outside loop'); |
1225 | return $op->next; # ignore the op |
1226 | } |
1227 | } else { |
1228 | $cxix = dopoptolabel($op->pv); |
1229 | if ($cxix < 0) { |
1230 | error('Label not found at compile time for "last %s"', $op->pv); |
1231 | return $op->next; # ignore the op |
1232 | } |
1233 | # XXX Add support for "last" to leave non-loop blocks |
1234 | if ($cxstack[$cxix]->{type} != CXt_LOOP) { |
1235 | error('Use of "last" for non-loop blocks is not yet implemented'); |
1236 | return $op->next; # ignore the op |
1237 | } |
1238 | } |
1239 | default_pp($op); |
1240 | my $lastop = $cxstack[$cxix]->{lastop}->next; |
1241 | push(@bblock_todo, $lastop); |
1242 | runtime(sprintf("goto %s;", label($lastop))); |
1243 | return $op->next; |
1244 | } |
1245 | |
1246 | sub pp_subst { |
1247 | my $op = shift; |
1248 | write_back_lexicals(); |
1249 | write_back_stack(); |
1250 | my $sym = doop($op); |
1251 | my $replroot = $op->pmreplroot; |
1252 | if ($$replroot) { |
81009501 |
1253 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplroot) goto %s;", |
a798dbf2 |
1254 | $sym, label($replroot)); |
1255 | $op->pmreplstart->save; |
1256 | push(@bblock_todo, $replroot); |
1257 | } |
1258 | invalidate_lexicals(); |
1259 | return $op->next; |
1260 | } |
1261 | |
1262 | sub pp_substcont { |
1263 | my $op = shift; |
1264 | write_back_lexicals(); |
1265 | write_back_stack(); |
1266 | doop($op); |
1267 | my $pmop = $op->other; |
0cc1d052 |
1268 | # warn sprintf("substcont: op = %s, pmop = %s\n", |
1269 | # peekop($op), peekop($pmop));#debug |
1270 | # my $pmopsym = objsym($pmop); |
a798dbf2 |
1271 | my $pmopsym = $pmop->save; # XXX can this recurse? |
0cc1d052 |
1272 | # warn "pmopsym = $pmopsym\n";#debug |
81009501 |
1273 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplstart) goto %s;", |
a798dbf2 |
1274 | $pmopsym, label($pmop->pmreplstart)); |
1275 | invalidate_lexicals(); |
1276 | return $pmop->next; |
1277 | } |
1278 | |
1279 | sub default_pp { |
1280 | my $op = shift; |
1281 | my $ppname = $op->ppaddr; |
1282 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
1283 | write_back_stack() unless $skip_stack{$ppname}; |
1284 | doop($op); |
1285 | # XXX If the only way that ops can write to a TEMPORARY lexical is |
1286 | # when it's named in $op->targ then we could call |
1287 | # invalidate_lexicals(TEMPORARY) and avoid having to write back all |
1288 | # the temporaries. For now, we'll play it safe and write back the lot. |
1289 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
1290 | return $op->next; |
1291 | } |
1292 | |
1293 | sub compile_op { |
1294 | my $op = shift; |
1295 | my $ppname = $op->ppaddr; |
1296 | if (exists $ignore_op{$ppname}) { |
1297 | return $op->next; |
1298 | } |
1299 | debug peek_stack() if $debug_stack; |
1300 | if ($debug_op) { |
1301 | debug sprintf("%s [%s]\n", |
1302 | peekop($op), |
1303 | $op->flags & OPf_STACKED ? "OPf_STACKED" : $op->targ); |
1304 | } |
1305 | no strict 'refs'; |
1306 | if (defined(&$ppname)) { |
1307 | $know_op = 0; |
1308 | return &$ppname($op); |
1309 | } else { |
1310 | return default_pp($op); |
1311 | } |
1312 | } |
1313 | |
1314 | sub compile_bblock { |
1315 | my $op = shift; |
1316 | #warn "compile_bblock: ", peekop($op), "\n"; # debug |
1317 | write_label($op); |
1318 | $know_op = 0; |
1319 | do { |
1320 | $op = compile_op($op); |
1321 | } while (defined($op) && $$op && !exists($leaders->{$$op})); |
1322 | write_back_stack(); # boo hoo: big loss |
1323 | reload_lexicals(); |
1324 | return $op; |
1325 | } |
1326 | |
1327 | sub cc { |
1328 | my ($name, $root, $start, @padlist) = @_; |
1329 | my $op; |
1330 | init_pp($name); |
1331 | load_pad(@padlist); |
1332 | B::Pseudoreg->new_scope; |
1333 | @cxstack = (); |
1334 | if ($debug_timings) { |
1335 | warn sprintf("Basic block analysis at %s\n", timing_info); |
1336 | } |
1337 | $leaders = find_leaders($root, $start); |
1338 | @bblock_todo = ($start, values %$leaders); |
1339 | if ($debug_timings) { |
1340 | warn sprintf("Compilation at %s\n", timing_info); |
1341 | } |
1342 | while (@bblock_todo) { |
1343 | $op = shift @bblock_todo; |
1344 | #warn sprintf("Considering basic block %s\n", peekop($op)); # debug |
1345 | next if !defined($op) || !$$op || $done{$$op}; |
1346 | #warn "...compiling it\n"; # debug |
1347 | do { |
1348 | $done{$$op} = 1; |
1349 | $op = compile_bblock($op); |
1350 | if ($need_freetmps && $freetmps_each_bblock) { |
1351 | runtime("FREETMPS;"); |
1352 | $need_freetmps = 0; |
1353 | } |
1354 | } while defined($op) && $$op && !$done{$$op}; |
1355 | if ($need_freetmps && $freetmps_each_loop) { |
1356 | runtime("FREETMPS;"); |
1357 | $need_freetmps = 0; |
1358 | } |
1359 | if (!$$op) { |
7de5877e |
1360 | runtime("PUTBACK;","return (PL_op)?PL_op->op_next:0;"); |
a798dbf2 |
1361 | } elsif ($done{$$op}) { |
1362 | runtime(sprintf("goto %s;", label($op))); |
1363 | } |
1364 | } |
1365 | if ($debug_timings) { |
1366 | warn sprintf("Saving runtime at %s\n", timing_info); |
1367 | } |
1368 | save_runtime(); |
1369 | } |
1370 | |
1371 | sub cc_recurse { |
1372 | my $ccinfo; |
1373 | my $start; |
1374 | $start = cc_queue(@_) if @_; |
1375 | while ($ccinfo = shift @cc_todo) { |
1376 | cc(@$ccinfo); |
1377 | } |
1378 | return $start; |
1379 | } |
1380 | |
1381 | sub cc_obj { |
1382 | my ($name, $cvref) = @_; |
1383 | my $cv = svref_2object($cvref); |
1384 | my @padlist = $cv->PADLIST->ARRAY; |
1385 | my $curpad_sym = $padlist[1]->save; |
1386 | cc_recurse($name, $cv->ROOT, $cv->START, @padlist); |
1387 | } |
1388 | |
1389 | sub cc_main { |
1390 | my @comppadlist = comppadlist->ARRAY; |
0cc1d052 |
1391 | my $curpad_nam = $comppadlist[0]->save; |
1392 | my $curpad_sym = $comppadlist[1]->save; |
1393 | my $init_av = init_av->save; |
1394 | my $inc_hv = svref_2object(\%INC)->save; |
1395 | my $inc_av = svref_2object(\@INC)->save; |
a798dbf2 |
1396 | my $start = cc_recurse("pp_main", main_root, main_start, @comppadlist); |
0cc1d052 |
1397 | save_unused_subs(); |
a798dbf2 |
1398 | cc_recurse(); |
1399 | |
1400 | return if $errors; |
1401 | if (!defined($module)) { |
81009501 |
1402 | $init->add(sprintf("PL_main_root = s\\_%x;", ${main_root()}), |
1403 | "PL_main_start = $start;", |
5cfd8ad4 |
1404 | "PL_curpad = AvARRAY($curpad_sym);", |
0cc1d052 |
1405 | "PL_initav = $init_av;", |
1406 | "GvHV(PL_incgv) = $inc_hv;", |
1407 | "GvAV(PL_incgv) = $inc_av;", |
5cfd8ad4 |
1408 | "av_store(CvPADLIST(PL_main_cv),0,SvREFCNT_inc($curpad_nam));", |
44887cfa |
1409 | "av_store(CvPADLIST(PL_main_cv),1,SvREFCNT_inc($curpad_sym));", |
1410 | ); |
1411 | |
a798dbf2 |
1412 | } |
1413 | output_boilerplate(); |
1414 | print "\n"; |
1415 | output_all("perl_init"); |
1416 | output_runtime(); |
1417 | print "\n"; |
1418 | output_main(); |
1419 | if (defined($module)) { |
1420 | my $cmodule = $module; |
1421 | $cmodule =~ s/::/__/g; |
1422 | print <<"EOT"; |
1423 | |
1424 | #include "XSUB.h" |
1425 | XS(boot_$cmodule) |
1426 | { |
1427 | dXSARGS; |
1428 | perl_init(); |
1429 | ENTER; |
1430 | SAVETMPS; |
81009501 |
1431 | SAVESPTR(PL_curpad); |
1432 | SAVESPTR(PL_op); |
1433 | PL_curpad = AvARRAY($curpad_sym); |
1434 | PL_op = $start; |
a798dbf2 |
1435 | pp_main(ARGS); |
1436 | FREETMPS; |
1437 | LEAVE; |
81009501 |
1438 | ST(0) = &PL_sv_yes; |
a798dbf2 |
1439 | XSRETURN(1); |
1440 | } |
1441 | EOT |
1442 | } |
1443 | if ($debug_timings) { |
1444 | warn sprintf("Done at %s\n", timing_info); |
1445 | } |
1446 | } |
1447 | |
1448 | sub compile { |
1449 | my @options = @_; |
1450 | my ($option, $opt, $arg); |
1451 | OPTION: |
1452 | while ($option = shift @options) { |
1453 | if ($option =~ /^-(.)(.*)/) { |
1454 | $opt = $1; |
1455 | $arg = $2; |
1456 | } else { |
1457 | unshift @options, $option; |
1458 | last OPTION; |
1459 | } |
1460 | if ($opt eq "-" && $arg eq "-") { |
1461 | shift @options; |
1462 | last OPTION; |
1463 | } elsif ($opt eq "o") { |
1464 | $arg ||= shift @options; |
ff06c60c |
1465 | open(STDOUT, ">$arg") or return "open '>$arg': $!\n"; |
a798dbf2 |
1466 | } elsif ($opt eq "n") { |
1467 | $arg ||= shift @options; |
1468 | $module_name = $arg; |
1469 | } elsif ($opt eq "u") { |
1470 | $arg ||= shift @options; |
0cc1d052 |
1471 | mark_unused($arg,undef); |
a798dbf2 |
1472 | } elsif ($opt eq "f") { |
1473 | $arg ||= shift @options; |
1474 | my $value = $arg !~ s/^no-//; |
1475 | $arg =~ s/-/_/g; |
1476 | my $ref = $optimise{$arg}; |
1477 | if (defined($ref)) { |
1478 | $$ref = $value; |
1479 | } else { |
1480 | warn qq(ignoring unknown optimisation option "$arg"\n); |
1481 | } |
1482 | } elsif ($opt eq "O") { |
1483 | $arg = 1 if $arg eq ""; |
1484 | my $ref; |
1485 | foreach $ref (values %optimise) { |
1486 | $$ref = 0; |
1487 | } |
1488 | if ($arg >= 2) { |
1489 | $freetmps_each_loop = 1; |
1490 | } |
1491 | if ($arg >= 1) { |
1492 | $freetmps_each_bblock = 1 unless $freetmps_each_loop; |
1493 | } |
1494 | } elsif ($opt eq "m") { |
1495 | $arg ||= shift @options; |
1496 | $module = $arg; |
1497 | push(@unused_sub_packages, $arg); |
1498 | } elsif ($opt eq "p") { |
1499 | $arg ||= shift @options; |
1500 | $patchlevel = $arg; |
1501 | } elsif ($opt eq "D") { |
1502 | $arg ||= shift @options; |
1503 | foreach $arg (split(//, $arg)) { |
1504 | if ($arg eq "o") { |
1505 | B->debug(1); |
1506 | } elsif ($arg eq "O") { |
1507 | $debug_op = 1; |
1508 | } elsif ($arg eq "s") { |
1509 | $debug_stack = 1; |
1510 | } elsif ($arg eq "c") { |
1511 | $debug_cxstack = 1; |
1512 | } elsif ($arg eq "p") { |
1513 | $debug_pad = 1; |
1514 | } elsif ($arg eq "r") { |
1515 | $debug_runtime = 1; |
1516 | } elsif ($arg eq "S") { |
1517 | $debug_shadow = 1; |
1518 | } elsif ($arg eq "q") { |
1519 | $debug_queue = 1; |
1520 | } elsif ($arg eq "l") { |
1521 | $debug_lineno = 1; |
1522 | } elsif ($arg eq "t") { |
1523 | $debug_timings = 1; |
1524 | } |
1525 | } |
1526 | } |
1527 | } |
1528 | init_sections(); |
1529 | $init = B::Section->get("init"); |
1530 | $decl = B::Section->get("decl"); |
1531 | |
1532 | if (@options) { |
1533 | return sub { |
1534 | my ($objname, $ppname); |
1535 | foreach $objname (@options) { |
1536 | $objname = "main::$objname" unless $objname =~ /::/; |
1537 | ($ppname = $objname) =~ s/^.*?:://; |
1538 | eval "cc_obj(qq(pp_sub_$ppname), \\&$objname)"; |
1539 | die "cc_obj(qq(pp_sub_$ppname, \\&$objname) failed: $@" if $@; |
1540 | return if $errors; |
1541 | } |
1542 | output_boilerplate(); |
1543 | print "\n"; |
1544 | output_all($module_name || "init_module"); |
1545 | output_runtime(); |
1546 | } |
1547 | } else { |
1548 | return sub { cc_main() }; |
1549 | } |
1550 | } |
1551 | |
1552 | 1; |
7f20e9dd |
1553 | |
1554 | __END__ |
1555 | |
1556 | =head1 NAME |
1557 | |
1558 | B::CC - Perl compiler's optimized C translation backend |
1559 | |
1560 | =head1 SYNOPSIS |
1561 | |
1562 | perl -MO=CC[,OPTIONS] foo.pl |
1563 | |
1564 | =head1 DESCRIPTION |
1565 | |
1a52ab62 |
1566 | This compiler backend takes Perl source and generates C source code |
1567 | corresponding to the flow of your program. In other words, this |
1568 | backend is somewhat a "real" compiler in the sense that many people |
1569 | think about compilers. Note however that, currently, it is a very |
1570 | poor compiler in that although it generates (mostly, or at least |
1571 | sometimes) correct code, it performs relatively few optimisations. |
1572 | This will change as the compiler develops. The result is that |
1573 | running an executable compiled with this backend may start up more |
1574 | quickly than running the original Perl program (a feature shared |
1575 | by the B<C> compiler backend--see F<B::C>) and may also execute |
1576 | slightly faster. This is by no means a good optimising compiler--yet. |
1577 | |
1578 | =head1 OPTIONS |
1579 | |
1580 | If there are any non-option arguments, they are taken to be |
1581 | names of objects to be saved (probably doesn't work properly yet). |
1582 | Without extra arguments, it saves the main program. |
1583 | |
1584 | =over 4 |
1585 | |
1586 | =item B<-ofilename> |
1587 | |
1588 | Output to filename instead of STDOUT |
1589 | |
1590 | =item B<-v> |
1591 | |
1592 | Verbose compilation (currently gives a few compilation statistics). |
1593 | |
1594 | =item B<--> |
1595 | |
1596 | Force end of options |
1597 | |
1598 | =item B<-uPackname> |
1599 | |
1600 | Force apparently unused subs from package Packname to be compiled. |
1601 | This allows programs to use eval "foo()" even when sub foo is never |
1602 | seen to be used at compile time. The down side is that any subs which |
1603 | really are never used also have code generated. This option is |
1604 | necessary, for example, if you have a signal handler foo which you |
1605 | initialise with C<$SIG{BAR} = "foo">. A better fix, though, is just |
1606 | to change it to C<$SIG{BAR} = \&foo>. You can have multiple B<-u> |
1607 | options. The compiler tries to figure out which packages may possibly |
1608 | have subs in which need compiling but the current version doesn't do |
1609 | it very well. In particular, it is confused by nested packages (i.e. |
1610 | of the form C<A::B>) where package C<A> does not contain any subs. |
1611 | |
1612 | =item B<-mModulename> |
1613 | |
1614 | Instead of generating source for a runnable executable, generate |
1615 | source for an XSUB module. The boot_Modulename function (which |
1616 | DynaLoader can look for) does the appropriate initialisation and runs |
1617 | the main part of the Perl source that is being compiled. |
1618 | |
1619 | |
1620 | =item B<-D> |
1621 | |
1622 | Debug options (concatenated or separate flags like C<perl -D>). |
1623 | |
1624 | =item B<-Dr> |
1625 | |
1626 | Writes debugging output to STDERR just as it's about to write to the |
1627 | program's runtime (otherwise writes debugging info as comments in |
1628 | its C output). |
1629 | |
1630 | =item B<-DO> |
1631 | |
1632 | Outputs each OP as it's compiled |
1633 | |
1634 | =item B<-Ds> |
1635 | |
1636 | Outputs the contents of the shadow stack at each OP |
1637 | |
1638 | =item B<-Dp> |
1639 | |
1640 | Outputs the contents of the shadow pad of lexicals as it's loaded for |
1641 | each sub or the main program. |
1642 | |
1643 | =item B<-Dq> |
1644 | |
1645 | Outputs the name of each fake PP function in the queue as it's about |
1646 | to process it. |
1647 | |
1648 | =item B<-Dl> |
1649 | |
1650 | Output the filename and line number of each original line of Perl |
1651 | code as it's processed (C<pp_nextstate>). |
1652 | |
1653 | =item B<-Dt> |
1654 | |
1655 | Outputs timing information of compilation stages. |
1656 | |
1657 | =item B<-f> |
1658 | |
1659 | Force optimisations on or off one at a time. |
1660 | |
1661 | =item B<-ffreetmps-each-bblock> |
1662 | |
1663 | Delays FREETMPS from the end of each statement to the end of the each |
1664 | basic block. |
1665 | |
1666 | =item B<-ffreetmps-each-loop> |
1667 | |
1668 | Delays FREETMPS from the end of each statement to the end of the group |
1669 | of basic blocks forming a loop. At most one of the freetmps-each-* |
1670 | options can be used. |
1671 | |
1672 | =item B<-fomit-taint> |
1673 | |
1674 | Omits generating code for handling perl's tainting mechanism. |
1675 | |
1676 | =item B<-On> |
1677 | |
1678 | Optimisation level (n = 0, 1, 2, ...). B<-O> means B<-O1>. |
1679 | Currently, B<-O1> sets B<-ffreetmps-each-bblock> and B<-O2> |
1680 | sets B<-ffreetmps-each-loop>. |
1681 | |
1682 | =back |
1683 | |
1684 | =head1 EXAMPLES |
1685 | |
1686 | perl -MO=CC,-O2,-ofoo.c foo.pl |
1687 | perl cc_harness -o foo foo.c |
1688 | |
1689 | Note that C<cc_harness> lives in the C<B> subdirectory of your perl |
1690 | library directory. The utility called C<perlcc> may also be used to |
1691 | help make use of this compiler. |
1692 | |
1693 | perl -MO=CC,-mFoo,-oFoo.c Foo.pm |
1694 | perl cc_harness -shared -c -o Foo.so Foo.c |
1695 | |
1696 | =head1 BUGS |
1697 | |
1698 | Plenty. Current status: experimental. |
1699 | |
1700 | =head1 DIFFERENCES |
1701 | |
1702 | These aren't really bugs but they are constructs which are heavily |
1703 | tied to perl's compile-and-go implementation and with which this |
1704 | compiler backend cannot cope. |
1705 | |
1706 | =head2 Loops |
1707 | |
1708 | Standard perl calculates the target of "next", "last", and "redo" |
1709 | at run-time. The compiler calculates the targets at compile-time. |
1710 | For example, the program |
1711 | |
1712 | sub skip_on_odd { next NUMBER if $_[0] % 2 } |
1713 | NUMBER: for ($i = 0; $i < 5; $i++) { |
1714 | skip_on_odd($i); |
1715 | print $i; |
1716 | } |
1717 | |
1718 | produces the output |
1719 | |
1720 | 024 |
1721 | |
1722 | with standard perl but gives a compile-time error with the compiler. |
1723 | |
1724 | =head2 Context of ".." |
1725 | |
1726 | The context (scalar or array) of the ".." operator determines whether |
1727 | it behaves as a range or a flip/flop. Standard perl delays until |
1728 | runtime the decision of which context it is in but the compiler needs |
1729 | to know the context at compile-time. For example, |
1730 | |
1731 | @a = (4,6,1,0,0,1); |
1732 | sub range { (shift @a)..(shift @a) } |
1733 | print range(); |
1734 | while (@a) { print scalar(range()) } |
1735 | |
1736 | generates the output |
1737 | |
1738 | 456123E0 |
1739 | |
1740 | with standard Perl but gives a compile-time error with compiled Perl. |
1741 | |
1742 | =head2 Arithmetic |
1743 | |
1744 | Compiled Perl programs use native C arithemtic much more frequently |
1745 | than standard perl. Operations on large numbers or on boundary |
1746 | cases may produce different behaviour. |
1747 | |
1748 | =head2 Deprecated features |
1749 | |
1750 | Features of standard perl such as C<$[> which have been deprecated |
1751 | in standard perl since Perl5 was released have not been implemented |
1752 | in the compiler. |
7f20e9dd |
1753 | |
1754 | =head1 AUTHOR |
1755 | |
1756 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
1757 | |
1758 | =cut |