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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 | |
a798dbf2 |
76 | my ($module_name); |
77 | my ($debug_op, $debug_stack, $debug_cxstack, $debug_pad, $debug_runtime, |
78 | $debug_shadow, $debug_queue, $debug_lineno, $debug_timings); |
79 | |
80 | # Optimisation options. On the command line, use hyphens instead of |
81 | # underscores for compatibility with gcc-style options. We use |
82 | # underscores here because they are OK in (strict) barewords. |
83 | my ($freetmps_each_bblock, $freetmps_each_loop, $omit_taint); |
84 | my %optimise = (freetmps_each_bblock => \$freetmps_each_bblock, |
85 | freetmps_each_loop => \$freetmps_each_loop, |
86 | omit_taint => \$omit_taint); |
87 | # perl patchlevel to generate code for (defaults to current patchlevel) |
88 | my $patchlevel = int(0.5 + 1000 * ($] - 5)); |
89 | |
90 | # Could rewrite push_runtime() and output_runtime() to use a |
91 | # temporary file if memory is at a premium. |
92 | my $ppname; # name of current fake PP function |
93 | my $runtime_list_ref; |
94 | my $declare_ref; # Hash ref keyed by C variable type of declarations. |
95 | |
96 | my @pp_list; # list of [$ppname, $runtime_list_ref, $declare_ref] |
97 | # tuples to be written out. |
98 | |
99 | my ($init, $decl); |
100 | |
101 | sub init_hash { map { $_ => 1 } @_ } |
102 | |
103 | # |
104 | # Initialise the hashes for the default PP functions where we can avoid |
105 | # either write_back_stack, write_back_lexicals or invalidate_lexicals. |
106 | # |
107 | %skip_lexicals = init_hash qw(pp_enter pp_enterloop); |
108 | %skip_invalidate = init_hash qw(pp_enter pp_enterloop); |
109 | |
110 | sub debug { |
111 | if ($debug_runtime) { |
112 | warn(@_); |
113 | } else { |
114 | runtime(map { chomp; "/* $_ */"} @_); |
115 | } |
116 | } |
117 | |
118 | sub declare { |
119 | my ($type, $var) = @_; |
120 | push(@{$declare_ref->{$type}}, $var); |
121 | } |
122 | |
123 | sub push_runtime { |
124 | push(@$runtime_list_ref, @_); |
125 | warn join("\n", @_) . "\n" if $debug_runtime; |
126 | } |
127 | |
128 | sub save_runtime { |
129 | push(@pp_list, [$ppname, $runtime_list_ref, $declare_ref]); |
130 | } |
131 | |
132 | sub output_runtime { |
133 | my $ppdata; |
134 | print qq(#include "cc_runtime.h"\n); |
135 | foreach $ppdata (@pp_list) { |
136 | my ($name, $runtime, $declare) = @$ppdata; |
137 | print "\nstatic\nPP($name)\n{\n"; |
138 | my ($type, $varlist, $line); |
139 | while (($type, $varlist) = each %$declare) { |
140 | print "\t$type ", join(", ", @$varlist), ";\n"; |
141 | } |
142 | foreach $line (@$runtime) { |
143 | print $line, "\n"; |
144 | } |
145 | print "}\n"; |
146 | } |
147 | } |
148 | |
149 | sub runtime { |
150 | my $line; |
151 | foreach $line (@_) { |
152 | push_runtime("\t$line"); |
153 | } |
154 | } |
155 | |
156 | sub init_pp { |
157 | $ppname = shift; |
158 | $runtime_list_ref = []; |
159 | $declare_ref = {}; |
160 | runtime("djSP;"); |
161 | declare("I32", "oldsave"); |
162 | declare("SV", "**svp"); |
163 | map { declare("SV", "*$_") } qw(sv src dst left right); |
164 | declare("MAGIC", "*mg"); |
165 | $decl->add("static OP * $ppname _((ARGSproto));"); |
166 | debug "init_pp: $ppname\n" if $debug_queue; |
167 | } |
168 | |
169 | # Initialise runtime_callback function for Stackobj class |
170 | BEGIN { B::Stackobj::set_callback(\&runtime) } |
171 | |
172 | # Initialise saveoptree_callback for B::C class |
173 | sub cc_queue { |
174 | my ($name, $root, $start, @pl) = @_; |
175 | debug "cc_queue: name $name, root $root, start $start, padlist (@pl)\n" |
176 | if $debug_queue; |
177 | if ($name eq "*ignore*") { |
178 | $name = 0; |
179 | } else { |
180 | push(@cc_todo, [$name, $root, $start, (@pl ? @pl : @padlist)]); |
181 | } |
182 | my $fakeop = new B::FAKEOP ("next" => 0, sibling => 0, ppaddr => $name); |
183 | $start = $fakeop->save; |
184 | debug "cc_queue: name $name returns $start\n" if $debug_queue; |
185 | return $start; |
186 | } |
187 | BEGIN { B::C::set_callback(\&cc_queue) } |
188 | |
189 | sub valid_int { $_[0]->{flags} & VALID_INT } |
190 | sub valid_double { $_[0]->{flags} & VALID_DOUBLE } |
191 | sub valid_numeric { $_[0]->{flags} & (VALID_INT | VALID_DOUBLE) } |
192 | sub valid_sv { $_[0]->{flags} & VALID_SV } |
193 | |
194 | sub top_int { @stack ? $stack[-1]->as_int : "TOPi" } |
195 | sub top_double { @stack ? $stack[-1]->as_double : "TOPn" } |
196 | sub top_numeric { @stack ? $stack[-1]->as_numeric : "TOPn" } |
197 | sub top_sv { @stack ? $stack[-1]->as_sv : "TOPs" } |
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198 | sub top_bool { @stack ? $stack[-1]->as_bool : "SvTRUE(TOPs)" } |
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199 | |
200 | sub pop_int { @stack ? (pop @stack)->as_int : "POPi" } |
201 | sub pop_double { @stack ? (pop @stack)->as_double : "POPn" } |
202 | sub pop_numeric { @stack ? (pop @stack)->as_numeric : "POPn" } |
203 | sub pop_sv { @stack ? (pop @stack)->as_sv : "POPs" } |
204 | sub pop_bool { |
205 | if (@stack) { |
ff144d38 |
206 | return ((pop @stack)->as_bool); |
a798dbf2 |
207 | } else { |
208 | # Careful: POPs has an auto-decrement and SvTRUE evaluates |
209 | # its argument more than once. |
210 | runtime("sv = POPs;"); |
211 | return "SvTRUE(sv)"; |
212 | } |
213 | } |
214 | |
215 | sub write_back_lexicals { |
216 | my $avoid = shift || 0; |
217 | debug "write_back_lexicals($avoid) called from @{[(caller(1))[3]]}\n" |
218 | if $debug_shadow; |
219 | my $lex; |
220 | foreach $lex (@pad) { |
221 | next unless ref($lex); |
222 | $lex->write_back unless $lex->{flags} & $avoid; |
223 | } |
224 | } |
225 | |
226 | sub write_back_stack { |
227 | my $obj; |
228 | return unless @stack; |
229 | runtime(sprintf("EXTEND(sp, %d);", scalar(@stack))); |
230 | foreach $obj (@stack) { |
231 | runtime(sprintf("PUSHs((SV*)%s);", $obj->as_sv)); |
232 | } |
233 | @stack = (); |
234 | } |
235 | |
236 | sub invalidate_lexicals { |
237 | my $avoid = shift || 0; |
238 | debug "invalidate_lexicals($avoid) called from @{[(caller(1))[3]]}\n" |
239 | if $debug_shadow; |
240 | my $lex; |
241 | foreach $lex (@pad) { |
242 | next unless ref($lex); |
243 | $lex->invalidate unless $lex->{flags} & $avoid; |
244 | } |
245 | } |
246 | |
247 | sub reload_lexicals { |
248 | my $lex; |
249 | foreach $lex (@pad) { |
250 | next unless ref($lex); |
251 | my $type = $lex->{type}; |
252 | if ($type == T_INT) { |
253 | $lex->as_int; |
254 | } elsif ($type == T_DOUBLE) { |
255 | $lex->as_double; |
256 | } else { |
257 | $lex->as_sv; |
258 | } |
259 | } |
260 | } |
261 | |
262 | { |
263 | package B::Pseudoreg; |
264 | # |
265 | # This class allocates pseudo-registers (OK, so they're C variables). |
266 | # |
267 | my %alloc; # Keyed by variable name. A value of 1 means the |
268 | # variable has been declared. A value of 2 means |
269 | # it's in use. |
270 | |
271 | sub new_scope { %alloc = () } |
272 | |
273 | sub new ($$$) { |
274 | my ($class, $type, $prefix) = @_; |
275 | my ($ptr, $i, $varname, $status, $obj); |
276 | $prefix =~ s/^(\**)//; |
277 | $ptr = $1; |
278 | $i = 0; |
279 | do { |
280 | $varname = "$prefix$i"; |
281 | $status = $alloc{$varname}; |
282 | } while $status == 2; |
283 | if ($status != 1) { |
284 | # Not declared yet |
285 | B::CC::declare($type, "$ptr$varname"); |
286 | $alloc{$varname} = 2; # declared and in use |
287 | } |
288 | $obj = bless \$varname, $class; |
289 | return $obj; |
290 | } |
291 | sub DESTROY { |
292 | my $obj = shift; |
293 | $alloc{$$obj} = 1; # no longer in use but still declared |
294 | } |
295 | } |
296 | { |
297 | package B::Shadow; |
298 | # |
299 | # This class gives a standard API for a perl object to shadow a |
300 | # C variable and only generate reloads/write-backs when necessary. |
301 | # |
302 | # Use $obj->load($foo) instead of runtime("shadowed_c_var = foo"). |
303 | # Use $obj->write_back whenever shadowed_c_var needs to be up to date. |
304 | # Use $obj->invalidate whenever an unknown function may have |
305 | # set shadow itself. |
306 | |
307 | sub new { |
308 | my ($class, $write_back) = @_; |
309 | # Object fields are perl shadow variable, validity flag |
310 | # (for *C* variable) and callback sub for write_back |
311 | # (passed perl shadow variable as argument). |
312 | bless [undef, 1, $write_back], $class; |
313 | } |
314 | sub load { |
315 | my ($obj, $newval) = @_; |
316 | $obj->[1] = 0; # C variable no longer valid |
317 | $obj->[0] = $newval; |
318 | } |
319 | sub write_back { |
320 | my $obj = shift; |
321 | if (!($obj->[1])) { |
322 | $obj->[1] = 1; # C variable will now be valid |
323 | &{$obj->[2]}($obj->[0]); |
324 | } |
325 | } |
326 | sub invalidate { $_[0]->[1] = 0 } # force C variable to be invalid |
327 | } |
328 | my $curcop = new B::Shadow (sub { |
329 | my $opsym = shift->save; |
81009501 |
330 | runtime("PL_curcop = (COP*)$opsym;"); |
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331 | }); |
332 | |
333 | # |
334 | # Context stack shadowing. Mimics stuff in pp_ctl.c, cop.h and so on. |
335 | # |
336 | sub dopoptoloop { |
337 | my $cxix = $#cxstack; |
338 | while ($cxix >= 0 && $cxstack[$cxix]->{type} != CXt_LOOP) { |
339 | $cxix--; |
340 | } |
341 | debug "dopoptoloop: returning $cxix" if $debug_cxstack; |
342 | return $cxix; |
343 | } |
344 | |
345 | sub dopoptolabel { |
346 | my $label = shift; |
347 | my $cxix = $#cxstack; |
2e51e4c9 |
348 | while ($cxix >= 0 && |
349 | ($cxstack[$cxix]->{type} != CXt_LOOP || |
350 | $cxstack[$cxix]->{label} ne $label)) { |
a798dbf2 |
351 | $cxix--; |
352 | } |
353 | debug "dopoptolabel: returning $cxix" if $debug_cxstack; |
354 | return $cxix; |
355 | } |
356 | |
357 | sub error { |
358 | my $format = shift; |
359 | my $file = $curcop->[0]->filegv->SV->PV; |
360 | my $line = $curcop->[0]->line; |
361 | $errors++; |
362 | if (@_) { |
363 | warn sprintf("%s:%d: $format\n", $file, $line, @_); |
364 | } else { |
365 | warn sprintf("%s:%d: %s\n", $file, $line, $format); |
366 | } |
367 | } |
368 | |
369 | # |
370 | # Load pad takes (the elements of) a PADLIST as arguments and loads |
371 | # up @pad with Stackobj-derived objects which represent those lexicals. |
372 | # If/when perl itself can generate type information (my int $foo) then |
373 | # we'll take advantage of that here. Until then, we'll use various hacks |
374 | # to tell the compiler when we want a lexical to be a particular type |
375 | # or to be a register. |
376 | # |
377 | sub load_pad { |
378 | my ($namelistav, $valuelistav) = @_; |
379 | @padlist = @_; |
380 | my @namelist = $namelistav->ARRAY; |
381 | my @valuelist = $valuelistav->ARRAY; |
382 | my $ix; |
383 | @pad = (); |
384 | debug "load_pad: $#namelist names, $#valuelist values\n" if $debug_pad; |
385 | # Temporary lexicals don't get named so it's possible for @valuelist |
386 | # to be strictly longer than @namelist. We count $ix up to the end of |
387 | # @valuelist but index into @namelist for the name. Any temporaries which |
388 | # run off the end of @namelist will make $namesv undefined and we treat |
389 | # that the same as having an explicit SPECIAL sv_undef object in @namelist. |
390 | # [XXX If/when @_ becomes a lexical, we must start at 0 here.] |
391 | for ($ix = 1; $ix < @valuelist; $ix++) { |
392 | my $namesv = $namelist[$ix]; |
393 | my $type = T_UNKNOWN; |
394 | my $flags = 0; |
395 | my $name = "tmp$ix"; |
396 | my $class = class($namesv); |
397 | if (!defined($namesv) || $class eq "SPECIAL") { |
81009501 |
398 | # temporaries have &PL_sv_undef instead of a PVNV for a name |
a798dbf2 |
399 | $flags = VALID_SV|TEMPORARY|REGISTER; |
400 | } else { |
401 | if ($namesv->PV =~ /^\$(.*)_([di])(r?)$/) { |
402 | $name = $1; |
403 | if ($2 eq "i") { |
404 | $type = T_INT; |
405 | $flags = VALID_SV|VALID_INT; |
406 | } elsif ($2 eq "d") { |
407 | $type = T_DOUBLE; |
408 | $flags = VALID_SV|VALID_DOUBLE; |
409 | } |
410 | $flags |= REGISTER if $3; |
411 | } |
412 | } |
413 | $pad[$ix] = new B::Stackobj::Padsv ($type, $flags, $ix, |
414 | "i_$name", "d_$name"); |
415 | declare("IV", $type == T_INT ? "i_$name = 0" : "i_$name"); |
416 | declare("double", $type == T_DOUBLE ? "d_$name = 0" : "d_$name"); |
81009501 |
417 | debug sprintf("PL_curpad[$ix] = %s\n", $pad[$ix]->peek) if $debug_pad; |
a798dbf2 |
418 | } |
419 | } |
420 | |
421 | # |
422 | # Debugging stuff |
423 | # |
424 | sub peek_stack { sprintf "stack = %s\n", join(" ", map($_->minipeek, @stack)) } |
425 | |
426 | # |
427 | # OP stuff |
428 | # |
429 | |
430 | sub label { |
431 | my $op = shift; |
432 | # XXX Preserve original label name for "real" labels? |
433 | return sprintf("lab_%x", $$op); |
434 | } |
435 | |
436 | sub write_label { |
437 | my $op = shift; |
438 | push_runtime(sprintf(" %s:", label($op))); |
439 | } |
440 | |
441 | sub loadop { |
442 | my $op = shift; |
443 | my $opsym = $op->save; |
81009501 |
444 | runtime("PL_op = $opsym;") unless $know_op; |
a798dbf2 |
445 | return $opsym; |
446 | } |
447 | |
448 | sub doop { |
449 | my $op = shift; |
450 | my $ppname = $op->ppaddr; |
451 | my $sym = loadop($op); |
452 | runtime("DOOP($ppname);"); |
453 | $know_op = 1; |
454 | return $sym; |
455 | } |
456 | |
457 | sub gimme { |
458 | my $op = shift; |
459 | my $flags = $op->flags; |
460 | return (($flags & OPf_KNOW) ? ($flags & OPf_LIST) : "dowantarray()"); |
461 | } |
462 | |
463 | # |
464 | # Code generation for PP code |
465 | # |
466 | |
467 | sub pp_null { |
468 | my $op = shift; |
469 | return $op->next; |
470 | } |
471 | |
472 | sub pp_stub { |
473 | my $op = shift; |
474 | my $gimme = gimme($op); |
475 | if ($gimme != 1) { |
476 | # XXX Change to push a constant sv_undef Stackobj onto @stack |
477 | write_back_stack(); |
81009501 |
478 | runtime("if ($gimme != G_ARRAY) XPUSHs(&PL_sv_undef);"); |
a798dbf2 |
479 | } |
480 | return $op->next; |
481 | } |
482 | |
483 | sub pp_unstack { |
484 | my $op = shift; |
485 | @stack = (); |
486 | runtime("PP_UNSTACK;"); |
487 | return $op->next; |
488 | } |
489 | |
490 | sub pp_and { |
491 | my $op = shift; |
492 | my $next = $op->next; |
493 | reload_lexicals(); |
494 | unshift(@bblock_todo, $next); |
495 | if (@stack >= 1) { |
496 | my $bool = pop_bool(); |
497 | write_back_stack(); |
44887cfa |
498 | runtime(sprintf("if (!$bool) {XPUSHs(&PL_sv_no); goto %s;}", label($next))); |
a798dbf2 |
499 | } else { |
500 | runtime(sprintf("if (!%s) goto %s;", top_bool(), label($next)), |
501 | "*sp--;"); |
502 | } |
503 | return $op->other; |
504 | } |
505 | |
506 | sub pp_or { |
507 | my $op = shift; |
508 | my $next = $op->next; |
509 | reload_lexicals(); |
510 | unshift(@bblock_todo, $next); |
511 | if (@stack >= 1) { |
44887cfa |
512 | my $bool = pop_bool @stack; |
a798dbf2 |
513 | write_back_stack(); |
44887cfa |
514 | runtime(sprintf("if (%s) { XPUSHs(&PL_sv_yes); goto %s; }", |
515 | $bool, label($next))); |
a798dbf2 |
516 | } else { |
517 | runtime(sprintf("if (%s) goto %s;", top_bool(), label($next)), |
518 | "*sp--;"); |
519 | } |
520 | return $op->other; |
521 | } |
522 | |
523 | sub pp_cond_expr { |
524 | my $op = shift; |
525 | my $false = $op->false; |
526 | unshift(@bblock_todo, $false); |
527 | reload_lexicals(); |
528 | my $bool = pop_bool(); |
529 | write_back_stack(); |
530 | runtime(sprintf("if (!$bool) goto %s;", label($false))); |
531 | return $op->true; |
532 | } |
533 | |
534 | sub pp_padsv { |
535 | my $op = shift; |
536 | my $ix = $op->targ; |
537 | push(@stack, $pad[$ix]); |
538 | if ($op->flags & OPf_MOD) { |
539 | my $private = $op->private; |
540 | if ($private & OPpLVAL_INTRO) { |
81009501 |
541 | runtime("SAVECLEARSV(PL_curpad[$ix]);"); |
a798dbf2 |
542 | } elsif ($private & OPpDEREF) { |
81009501 |
543 | runtime(sprintf("vivify_ref(PL_curpad[%d], %d);", |
a798dbf2 |
544 | $ix, $private & OPpDEREF)); |
545 | $pad[$ix]->invalidate; |
546 | } |
547 | } |
548 | return $op->next; |
549 | } |
550 | |
551 | sub pp_const { |
552 | my $op = shift; |
553 | my $sv = $op->sv; |
554 | my $obj = $constobj{$$sv}; |
555 | if (!defined($obj)) { |
556 | $obj = $constobj{$$sv} = new B::Stackobj::Const ($sv); |
557 | } |
558 | push(@stack, $obj); |
559 | return $op->next; |
560 | } |
561 | |
562 | sub pp_nextstate { |
563 | my $op = shift; |
564 | $curcop->load($op); |
565 | @stack = (); |
566 | debug(sprintf("%s:%d\n", $op->filegv->SV->PV, $op->line)) if $debug_lineno; |
567 | runtime("TAINT_NOT;") unless $omit_taint; |
81009501 |
568 | runtime("sp = PL_stack_base + cxstack[cxstack_ix].blk_oldsp;"); |
a798dbf2 |
569 | if ($freetmps_each_bblock || $freetmps_each_loop) { |
570 | $need_freetmps = 1; |
571 | } else { |
572 | runtime("FREETMPS;"); |
573 | } |
574 | return $op->next; |
575 | } |
576 | |
577 | sub pp_dbstate { |
578 | my $op = shift; |
579 | $curcop->invalidate; # XXX? |
580 | return default_pp($op); |
581 | } |
582 | |
583 | sub pp_rv2gv { $curcop->write_back; default_pp(@_) } |
584 | sub pp_bless { $curcop->write_back; default_pp(@_) } |
585 | sub pp_repeat { $curcop->write_back; default_pp(@_) } |
586 | # The following subs need $curcop->write_back if we decide to support arybase: |
587 | # pp_pos, pp_substr, pp_index, pp_rindex, pp_aslice, pp_lslice, pp_splice |
588 | sub pp_sort { $curcop->write_back; default_pp(@_) } |
589 | sub pp_caller { $curcop->write_back; default_pp(@_) } |
590 | sub pp_reset { $curcop->write_back; default_pp(@_) } |
591 | |
592 | sub pp_gv { |
593 | my $op = shift; |
594 | my $gvsym = $op->gv->save; |
595 | write_back_stack(); |
596 | runtime("XPUSHs((SV*)$gvsym);"); |
597 | return $op->next; |
598 | } |
599 | |
600 | sub pp_gvsv { |
601 | my $op = shift; |
602 | my $gvsym = $op->gv->save; |
603 | write_back_stack(); |
604 | if ($op->private & OPpLVAL_INTRO) { |
605 | runtime("XPUSHs(save_scalar($gvsym));"); |
606 | } else { |
607 | runtime("XPUSHs(GvSV($gvsym));"); |
608 | } |
609 | return $op->next; |
610 | } |
611 | |
612 | sub pp_aelemfast { |
613 | my $op = shift; |
614 | my $gvsym = $op->gv->save; |
615 | my $ix = $op->private; |
616 | my $flag = $op->flags & OPf_MOD; |
617 | write_back_stack(); |
618 | runtime("svp = av_fetch(GvAV($gvsym), $ix, $flag);", |
81009501 |
619 | "PUSHs(svp ? *svp : &PL_sv_undef);"); |
a798dbf2 |
620 | return $op->next; |
621 | } |
622 | |
623 | sub int_binop { |
624 | my ($op, $operator) = @_; |
625 | if ($op->flags & OPf_STACKED) { |
626 | my $right = pop_int(); |
627 | if (@stack >= 1) { |
628 | my $left = top_int(); |
629 | $stack[-1]->set_int(&$operator($left, $right)); |
630 | } else { |
631 | runtime(sprintf("sv_setiv(TOPs, %s);",&$operator("TOPi", $right))); |
632 | } |
633 | } else { |
634 | my $targ = $pad[$op->targ]; |
635 | my $right = new B::Pseudoreg ("IV", "riv"); |
636 | my $left = new B::Pseudoreg ("IV", "liv"); |
637 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int)); |
638 | $targ->set_int(&$operator($$left, $$right)); |
639 | push(@stack, $targ); |
640 | } |
641 | return $op->next; |
642 | } |
643 | |
644 | sub INTS_CLOSED () { 0x1 } |
645 | sub INT_RESULT () { 0x2 } |
646 | sub NUMERIC_RESULT () { 0x4 } |
647 | |
648 | sub numeric_binop { |
649 | my ($op, $operator, $flags) = @_; |
650 | my $force_int = 0; |
651 | $force_int ||= ($flags & INT_RESULT); |
652 | $force_int ||= ($flags & INTS_CLOSED && @stack >= 2 |
653 | && valid_int($stack[-2]) && valid_int($stack[-1])); |
654 | if ($op->flags & OPf_STACKED) { |
655 | my $right = pop_numeric(); |
656 | if (@stack >= 1) { |
657 | my $left = top_numeric(); |
658 | if ($force_int) { |
659 | $stack[-1]->set_int(&$operator($left, $right)); |
660 | } else { |
661 | $stack[-1]->set_numeric(&$operator($left, $right)); |
662 | } |
663 | } else { |
664 | if ($force_int) { |
665 | runtime(sprintf("sv_setiv(TOPs, %s);", |
666 | &$operator("TOPi", $right))); |
667 | } else { |
668 | runtime(sprintf("sv_setnv(TOPs, %s);", |
669 | &$operator("TOPn", $right))); |
670 | } |
671 | } |
672 | } else { |
673 | my $targ = $pad[$op->targ]; |
674 | $force_int ||= ($targ->{type} == T_INT); |
675 | if ($force_int) { |
676 | my $right = new B::Pseudoreg ("IV", "riv"); |
677 | my $left = new B::Pseudoreg ("IV", "liv"); |
678 | runtime(sprintf("$$right = %s; $$left = %s;", |
679 | pop_numeric(), pop_numeric)); |
680 | $targ->set_int(&$operator($$left, $$right)); |
681 | } else { |
682 | my $right = new B::Pseudoreg ("double", "rnv"); |
683 | my $left = new B::Pseudoreg ("double", "lnv"); |
684 | runtime(sprintf("$$right = %s; $$left = %s;", |
685 | pop_numeric(), pop_numeric)); |
686 | $targ->set_numeric(&$operator($$left, $$right)); |
687 | } |
688 | push(@stack, $targ); |
689 | } |
690 | return $op->next; |
691 | } |
692 | |
693 | sub sv_binop { |
694 | my ($op, $operator, $flags) = @_; |
695 | if ($op->flags & OPf_STACKED) { |
696 | my $right = pop_sv(); |
697 | if (@stack >= 1) { |
698 | my $left = top_sv(); |
699 | if ($flags & INT_RESULT) { |
700 | $stack[-1]->set_int(&$operator($left, $right)); |
701 | } elsif ($flags & NUMERIC_RESULT) { |
702 | $stack[-1]->set_numeric(&$operator($left, $right)); |
703 | } else { |
704 | # XXX Does this work? |
705 | runtime(sprintf("sv_setsv($left, %s);", |
706 | &$operator($left, $right))); |
707 | $stack[-1]->invalidate; |
708 | } |
709 | } else { |
710 | my $f; |
711 | if ($flags & INT_RESULT) { |
712 | $f = "sv_setiv"; |
713 | } elsif ($flags & NUMERIC_RESULT) { |
714 | $f = "sv_setnv"; |
715 | } else { |
716 | $f = "sv_setsv"; |
717 | } |
718 | runtime(sprintf("%s(TOPs, %s);", $f, &$operator("TOPs", $right))); |
719 | } |
720 | } else { |
721 | my $targ = $pad[$op->targ]; |
722 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv)); |
723 | if ($flags & INT_RESULT) { |
724 | $targ->set_int(&$operator("left", "right")); |
725 | } elsif ($flags & NUMERIC_RESULT) { |
726 | $targ->set_numeric(&$operator("left", "right")); |
727 | } else { |
728 | # XXX Does this work? |
729 | runtime(sprintf("sv_setsv(%s, %s);", |
730 | $targ->as_sv, &$operator("left", "right"))); |
731 | $targ->invalidate; |
732 | } |
733 | push(@stack, $targ); |
734 | } |
735 | return $op->next; |
736 | } |
737 | |
738 | sub bool_int_binop { |
739 | my ($op, $operator) = @_; |
740 | my $right = new B::Pseudoreg ("IV", "riv"); |
741 | my $left = new B::Pseudoreg ("IV", "liv"); |
742 | runtime(sprintf("$$right = %s; $$left = %s;", pop_int(), pop_int())); |
743 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
744 | $bool->set_int(&$operator($$left, $$right)); |
745 | push(@stack, $bool); |
746 | return $op->next; |
747 | } |
748 | |
749 | sub bool_numeric_binop { |
750 | my ($op, $operator) = @_; |
751 | my $right = new B::Pseudoreg ("double", "rnv"); |
752 | my $left = new B::Pseudoreg ("double", "lnv"); |
753 | runtime(sprintf("$$right = %s; $$left = %s;", |
754 | pop_numeric(), pop_numeric())); |
755 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
756 | $bool->set_numeric(&$operator($$left, $$right)); |
757 | push(@stack, $bool); |
758 | return $op->next; |
759 | } |
760 | |
761 | sub bool_sv_binop { |
762 | my ($op, $operator) = @_; |
763 | runtime(sprintf("right = %s; left = %s;", pop_sv(), pop_sv())); |
764 | my $bool = new B::Stackobj::Bool (new B::Pseudoreg ("int", "b")); |
765 | $bool->set_numeric(&$operator("left", "right")); |
766 | push(@stack, $bool); |
767 | return $op->next; |
768 | } |
769 | |
770 | sub infix_op { |
771 | my $opname = shift; |
772 | return sub { "$_[0] $opname $_[1]" } |
773 | } |
774 | |
775 | sub prefix_op { |
776 | my $opname = shift; |
777 | return sub { sprintf("%s(%s)", $opname, join(", ", @_)) } |
778 | } |
779 | |
780 | BEGIN { |
781 | my $plus_op = infix_op("+"); |
782 | my $minus_op = infix_op("-"); |
783 | my $multiply_op = infix_op("*"); |
784 | my $divide_op = infix_op("/"); |
785 | my $modulo_op = infix_op("%"); |
786 | my $lshift_op = infix_op("<<"); |
a0d31f98 |
787 | my $rshift_op = infix_op(">>"); |
a798dbf2 |
788 | my $ncmp_op = sub { "($_[0] > $_[1] ? 1 : ($_[0] < $_[1]) ? -1 : 0)" }; |
789 | my $scmp_op = prefix_op("sv_cmp"); |
790 | my $seq_op = prefix_op("sv_eq"); |
791 | my $sne_op = prefix_op("!sv_eq"); |
792 | my $slt_op = sub { "sv_cmp($_[0], $_[1]) < 0" }; |
793 | my $sgt_op = sub { "sv_cmp($_[0], $_[1]) > 0" }; |
794 | my $sle_op = sub { "sv_cmp($_[0], $_[1]) <= 0" }; |
795 | my $sge_op = sub { "sv_cmp($_[0], $_[1]) >= 0" }; |
796 | my $eq_op = infix_op("=="); |
797 | my $ne_op = infix_op("!="); |
798 | my $lt_op = infix_op("<"); |
799 | my $gt_op = infix_op(">"); |
800 | my $le_op = infix_op("<="); |
801 | my $ge_op = infix_op(">="); |
802 | |
803 | # |
804 | # XXX The standard perl PP code has extra handling for |
805 | # some special case arguments of these operators. |
806 | # |
807 | sub pp_add { numeric_binop($_[0], $plus_op, INTS_CLOSED) } |
808 | sub pp_subtract { numeric_binop($_[0], $minus_op, INTS_CLOSED) } |
809 | sub pp_multiply { numeric_binop($_[0], $multiply_op, INTS_CLOSED) } |
810 | sub pp_divide { numeric_binop($_[0], $divide_op) } |
811 | sub pp_modulo { int_binop($_[0], $modulo_op) } # differs from perl's |
812 | sub pp_ncmp { numeric_binop($_[0], $ncmp_op, INT_RESULT) } |
813 | |
814 | sub pp_left_shift { int_binop($_[0], $lshift_op) } |
815 | sub pp_right_shift { int_binop($_[0], $rshift_op) } |
816 | sub pp_i_add { int_binop($_[0], $plus_op) } |
817 | sub pp_i_subtract { int_binop($_[0], $minus_op) } |
818 | sub pp_i_multiply { int_binop($_[0], $multiply_op) } |
819 | sub pp_i_divide { int_binop($_[0], $divide_op) } |
820 | sub pp_i_modulo { int_binop($_[0], $modulo_op) } |
821 | |
822 | sub pp_eq { bool_numeric_binop($_[0], $eq_op) } |
823 | sub pp_ne { bool_numeric_binop($_[0], $ne_op) } |
824 | sub pp_lt { bool_numeric_binop($_[0], $lt_op) } |
825 | sub pp_gt { bool_numeric_binop($_[0], $gt_op) } |
826 | sub pp_le { bool_numeric_binop($_[0], $le_op) } |
827 | sub pp_ge { bool_numeric_binop($_[0], $ge_op) } |
828 | |
829 | sub pp_i_eq { bool_int_binop($_[0], $eq_op) } |
830 | sub pp_i_ne { bool_int_binop($_[0], $ne_op) } |
831 | sub pp_i_lt { bool_int_binop($_[0], $lt_op) } |
832 | sub pp_i_gt { bool_int_binop($_[0], $gt_op) } |
833 | sub pp_i_le { bool_int_binop($_[0], $le_op) } |
834 | sub pp_i_ge { bool_int_binop($_[0], $ge_op) } |
835 | |
836 | sub pp_scmp { sv_binop($_[0], $scmp_op, INT_RESULT) } |
837 | sub pp_slt { bool_sv_binop($_[0], $slt_op) } |
838 | sub pp_sgt { bool_sv_binop($_[0], $sgt_op) } |
839 | sub pp_sle { bool_sv_binop($_[0], $sle_op) } |
840 | sub pp_sge { bool_sv_binop($_[0], $sge_op) } |
841 | sub pp_seq { bool_sv_binop($_[0], $seq_op) } |
842 | sub pp_sne { bool_sv_binop($_[0], $sne_op) } |
843 | } |
844 | |
845 | |
846 | sub pp_sassign { |
847 | my $op = shift; |
848 | my $backwards = $op->private & OPpASSIGN_BACKWARDS; |
849 | my ($dst, $src); |
850 | if (@stack >= 2) { |
851 | $dst = pop @stack; |
852 | $src = pop @stack; |
853 | ($src, $dst) = ($dst, $src) if $backwards; |
854 | my $type = $src->{type}; |
855 | if ($type == T_INT) { |
856 | $dst->set_int($src->as_int); |
857 | } elsif ($type == T_DOUBLE) { |
858 | $dst->set_numeric($src->as_numeric); |
859 | } else { |
860 | $dst->set_sv($src->as_sv); |
861 | } |
862 | push(@stack, $dst); |
863 | } elsif (@stack == 1) { |
864 | if ($backwards) { |
865 | my $src = pop @stack; |
866 | my $type = $src->{type}; |
81009501 |
867 | runtime("if (PL_tainting && PL_tainted) TAINT_NOT;"); |
a798dbf2 |
868 | if ($type == T_INT) { |
869 | runtime sprintf("sv_setiv(TOPs, %s);", $src->as_int); |
870 | } elsif ($type == T_DOUBLE) { |
871 | runtime sprintf("sv_setnv(TOPs, %s);", $src->as_double); |
872 | } else { |
873 | runtime sprintf("sv_setsv(TOPs, %s);", $src->as_sv); |
874 | } |
875 | runtime("SvSETMAGIC(TOPs);"); |
876 | } else { |
b8f1fa48 |
877 | my $dst = $stack[-1]; |
a798dbf2 |
878 | my $type = $dst->{type}; |
879 | runtime("sv = POPs;"); |
880 | runtime("MAYBE_TAINT_SASSIGN_SRC(sv);"); |
881 | if ($type == T_INT) { |
882 | $dst->set_int("SvIV(sv)"); |
883 | } elsif ($type == T_DOUBLE) { |
884 | $dst->set_double("SvNV(sv)"); |
885 | } else { |
886 | runtime("SvSetSV($dst->{sv}, sv);"); |
887 | $dst->invalidate; |
888 | } |
889 | } |
890 | } else { |
891 | if ($backwards) { |
892 | runtime("src = POPs; dst = TOPs;"); |
893 | } else { |
894 | runtime("dst = POPs; src = TOPs;"); |
895 | } |
896 | runtime("MAYBE_TAINT_SASSIGN_SRC(src);", |
897 | "SvSetSV(dst, src);", |
898 | "SvSETMAGIC(dst);", |
899 | "SETs(dst);"); |
900 | } |
901 | return $op->next; |
902 | } |
903 | |
904 | sub pp_preinc { |
905 | my $op = shift; |
906 | if (@stack >= 1) { |
907 | my $obj = $stack[-1]; |
908 | my $type = $obj->{type}; |
909 | if ($type == T_INT || $type == T_DOUBLE) { |
910 | $obj->set_int($obj->as_int . " + 1"); |
911 | } else { |
912 | runtime sprintf("PP_PREINC(%s);", $obj->as_sv); |
913 | $obj->invalidate(); |
914 | } |
915 | } else { |
916 | runtime sprintf("PP_PREINC(TOPs);"); |
917 | } |
918 | return $op->next; |
919 | } |
920 | |
921 | sub pp_pushmark { |
922 | my $op = shift; |
923 | write_back_stack(); |
924 | runtime("PUSHMARK(sp);"); |
925 | return $op->next; |
926 | } |
927 | |
928 | sub pp_list { |
929 | my $op = shift; |
930 | write_back_stack(); |
931 | my $gimme = gimme($op); |
932 | if ($gimme == 1) { # sic |
933 | runtime("POPMARK;"); # need this even though not a "full" pp_list |
934 | } else { |
935 | runtime("PP_LIST($gimme);"); |
936 | } |
937 | return $op->next; |
938 | } |
939 | |
940 | sub pp_entersub { |
941 | my $op = shift; |
942 | write_back_lexicals(REGISTER|TEMPORARY); |
943 | write_back_stack(); |
944 | my $sym = doop($op); |
5cfd8ad4 |
945 | runtime("while (PL_op != ($sym)->op_next && PL_op != (OP*)0 ){"); |
946 | runtime("PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
947 | runtime("SPAGAIN;}"); |
a798dbf2 |
948 | $know_op = 0; |
949 | invalidate_lexicals(REGISTER|TEMPORARY); |
950 | return $op->next; |
951 | } |
952 | |
5cfd8ad4 |
953 | sub pp_goto{ |
954 | |
955 | my $op = shift; |
956 | my $ppname = $op->ppaddr; |
957 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
958 | write_back_stack() unless $skip_stack{$ppname}; |
959 | my $sym=doop($op); |
960 | runtime("if (PL_op != ($sym)->op_next && PL_op != (OP*)0){return PL_op;}"); |
961 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
962 | return $op->next; |
963 | } |
a798dbf2 |
964 | sub pp_enterwrite { |
965 | my $op = shift; |
966 | pp_entersub($op); |
967 | } |
968 | |
969 | sub pp_leavewrite { |
970 | my $op = shift; |
971 | write_back_lexicals(REGISTER|TEMPORARY); |
972 | write_back_stack(); |
973 | my $sym = doop($op); |
974 | # XXX Is this the right way to distinguish between it returning |
975 | # CvSTART(cv) (via doform) and pop_return()? |
81009501 |
976 | runtime("if (PL_op) PL_op = (*PL_op->op_ppaddr)(ARGS);"); |
a798dbf2 |
977 | runtime("SPAGAIN;"); |
978 | $know_op = 0; |
979 | invalidate_lexicals(REGISTER|TEMPORARY); |
980 | return $op->next; |
981 | } |
982 | |
983 | sub doeval { |
984 | my $op = shift; |
985 | $curcop->write_back; |
986 | write_back_lexicals(REGISTER|TEMPORARY); |
987 | write_back_stack(); |
988 | my $sym = loadop($op); |
989 | my $ppaddr = $op->ppaddr; |
990 | runtime("PP_EVAL($ppaddr, ($sym)->op_next);"); |
991 | $know_op = 1; |
992 | invalidate_lexicals(REGISTER|TEMPORARY); |
993 | return $op->next; |
994 | } |
995 | |
996 | sub pp_entereval { doeval(@_) } |
997 | sub pp_require { doeval(@_) } |
998 | sub pp_dofile { doeval(@_) } |
999 | |
1000 | sub pp_entertry { |
1001 | my $op = shift; |
1002 | $curcop->write_back; |
1003 | write_back_lexicals(REGISTER|TEMPORARY); |
1004 | write_back_stack(); |
1005 | my $sym = doop($op); |
1006 | my $jmpbuf = sprintf("jmpbuf%d", $jmpbuf_ix++); |
1007 | declare("Sigjmp_buf", $jmpbuf); |
1008 | runtime(sprintf("PP_ENTERTRY(%s,%s);", $jmpbuf, label($op->other->next))); |
1009 | invalidate_lexicals(REGISTER|TEMPORARY); |
1010 | return $op->next; |
1011 | } |
1012 | |
1013 | sub pp_grepstart { |
1014 | my $op = shift; |
1015 | if ($need_freetmps && $freetmps_each_loop) { |
1016 | runtime("FREETMPS;"); # otherwise the grepwhile loop messes things up |
1017 | $need_freetmps = 0; |
1018 | } |
1019 | write_back_stack(); |
1020 | doop($op); |
1021 | return $op->next->other; |
1022 | } |
1023 | |
1024 | sub pp_mapstart { |
1025 | my $op = shift; |
1026 | if ($need_freetmps && $freetmps_each_loop) { |
1027 | runtime("FREETMPS;"); # otherwise the mapwhile loop messes things up |
1028 | $need_freetmps = 0; |
1029 | } |
1030 | write_back_stack(); |
1031 | doop($op); |
1032 | return $op->next->other; |
1033 | } |
1034 | |
1035 | sub pp_grepwhile { |
1036 | my $op = shift; |
1037 | my $next = $op->next; |
1038 | unshift(@bblock_todo, $next); |
1039 | write_back_lexicals(); |
1040 | write_back_stack(); |
1041 | my $sym = doop($op); |
1042 | # pp_grepwhile can return either op_next or op_other and we need to |
1043 | # be able to distinguish the two at runtime. Since it's possible for |
1044 | # both ops to be "inlined", the fields could both be zero. To get |
1045 | # around that, we hack op_next to be our own op (purely because we |
1046 | # know it's a non-NULL pointer and can't be the same as op_other). |
1047 | $init->add("((LOGOP*)$sym)->op_next = $sym;"); |
81009501 |
1048 | runtime(sprintf("if (PL_op == ($sym)->op_next) goto %s;", label($next))); |
a798dbf2 |
1049 | $know_op = 0; |
1050 | return $op->other; |
1051 | } |
1052 | |
1053 | sub pp_mapwhile { |
1054 | pp_grepwhile(@_); |
1055 | } |
1056 | |
1057 | sub pp_return { |
1058 | my $op = shift; |
1059 | write_back_lexicals(REGISTER|TEMPORARY); |
1060 | write_back_stack(); |
1061 | doop($op); |
7dbaefaf |
1062 | runtime("PUTBACK;", "return PL_op;"); |
a798dbf2 |
1063 | $know_op = 0; |
1064 | return $op->next; |
1065 | } |
1066 | |
1067 | sub nyi { |
1068 | my $op = shift; |
1069 | warn sprintf("%s not yet implemented properly\n", $op->ppaddr); |
1070 | return default_pp($op); |
1071 | } |
1072 | |
1073 | sub pp_range { |
1074 | my $op = shift; |
1075 | my $flags = $op->flags; |
1076 | if (!($flags & OPf_KNOW)) { |
1077 | error("context of range unknown at compile-time"); |
1078 | } |
1079 | write_back_lexicals(); |
1080 | write_back_stack(); |
1081 | if (!($flags & OPf_LIST)) { |
1082 | # We need to save our UNOP structure since pp_flop uses |
1083 | # it to find and adjust out targ. We don't need it ourselves. |
1084 | $op->save; |
81009501 |
1085 | runtime sprintf("if (SvTRUE(PL_curpad[%d])) goto %s;", |
a798dbf2 |
1086 | $op->targ, label($op->false)); |
1087 | unshift(@bblock_todo, $op->false); |
1088 | } |
1089 | return $op->true; |
1090 | } |
1091 | |
1092 | sub pp_flip { |
1093 | my $op = shift; |
1094 | my $flags = $op->flags; |
1095 | if (!($flags & OPf_KNOW)) { |
1096 | error("context of flip unknown at compile-time"); |
1097 | } |
1098 | if ($flags & OPf_LIST) { |
1099 | return $op->first->false; |
1100 | } |
1101 | write_back_lexicals(); |
1102 | write_back_stack(); |
1103 | # We need to save our UNOP structure since pp_flop uses |
1104 | # it to find and adjust out targ. We don't need it ourselves. |
1105 | $op->save; |
1106 | my $ix = $op->targ; |
1107 | my $rangeix = $op->first->targ; |
1108 | runtime(($op->private & OPpFLIP_LINENUM) ? |
81009501 |
1109 | "if (PL_last_in_gv && SvIV(TOPs) == IoLINES(GvIOp(PL_last_in_gv))) {" |
a798dbf2 |
1110 | : "if (SvTRUE(TOPs)) {"); |
81009501 |
1111 | runtime("\tsv_setiv(PL_curpad[$rangeix], 1);"); |
a798dbf2 |
1112 | if ($op->flags & OPf_SPECIAL) { |
81009501 |
1113 | runtime("sv_setiv(PL_curpad[$ix], 1);"); |
a798dbf2 |
1114 | } else { |
81009501 |
1115 | runtime("\tsv_setiv(PL_curpad[$ix], 0);", |
a798dbf2 |
1116 | "\tsp--;", |
1117 | sprintf("\tgoto %s;", label($op->first->false))); |
1118 | } |
1119 | runtime("}", |
81009501 |
1120 | qq{sv_setpv(PL_curpad[$ix], "");}, |
1121 | "SETs(PL_curpad[$ix]);"); |
a798dbf2 |
1122 | $know_op = 0; |
1123 | return $op->next; |
1124 | } |
1125 | |
1126 | sub pp_flop { |
1127 | my $op = shift; |
1128 | default_pp($op); |
1129 | $know_op = 0; |
1130 | return $op->next; |
1131 | } |
1132 | |
1133 | sub enterloop { |
1134 | my $op = shift; |
1135 | my $nextop = $op->nextop; |
1136 | my $lastop = $op->lastop; |
1137 | my $redoop = $op->redoop; |
1138 | $curcop->write_back; |
1139 | debug "enterloop: pushing on cxstack" if $debug_cxstack; |
1140 | push(@cxstack, { |
1141 | type => CXt_LOOP, |
1142 | op => $op, |
1143 | "label" => $curcop->[0]->label, |
1144 | nextop => $nextop, |
1145 | lastop => $lastop, |
1146 | redoop => $redoop |
1147 | }); |
1148 | $nextop->save; |
1149 | $lastop->save; |
1150 | $redoop->save; |
1151 | return default_pp($op); |
1152 | } |
1153 | |
1154 | sub pp_enterloop { enterloop(@_) } |
1155 | sub pp_enteriter { enterloop(@_) } |
1156 | |
1157 | sub pp_leaveloop { |
1158 | my $op = shift; |
1159 | if (!@cxstack) { |
1160 | die "panic: leaveloop"; |
1161 | } |
1162 | debug "leaveloop: popping from cxstack" if $debug_cxstack; |
1163 | pop(@cxstack); |
1164 | return default_pp($op); |
1165 | } |
1166 | |
1167 | sub pp_next { |
1168 | my $op = shift; |
1169 | my $cxix; |
1170 | if ($op->flags & OPf_SPECIAL) { |
1171 | $cxix = dopoptoloop(); |
1172 | if ($cxix < 0) { |
1173 | error('"next" used outside loop'); |
1174 | return $op->next; # ignore the op |
1175 | } |
1176 | } else { |
1177 | $cxix = dopoptolabel($op->pv); |
1178 | if ($cxix < 0) { |
1179 | error('Label not found at compile time for "next %s"', $op->pv); |
1180 | return $op->next; # ignore the op |
1181 | } |
1182 | } |
1183 | default_pp($op); |
1184 | my $nextop = $cxstack[$cxix]->{nextop}; |
1185 | push(@bblock_todo, $nextop); |
1186 | runtime(sprintf("goto %s;", label($nextop))); |
1187 | return $op->next; |
1188 | } |
1189 | |
1190 | sub pp_redo { |
1191 | my $op = shift; |
1192 | my $cxix; |
1193 | if ($op->flags & OPf_SPECIAL) { |
1194 | $cxix = dopoptoloop(); |
1195 | if ($cxix < 0) { |
1196 | error('"redo" used outside loop'); |
1197 | return $op->next; # ignore the op |
1198 | } |
1199 | } else { |
1200 | $cxix = dopoptolabel($op->pv); |
1201 | if ($cxix < 0) { |
1202 | error('Label not found at compile time for "redo %s"', $op->pv); |
1203 | return $op->next; # ignore the op |
1204 | } |
1205 | } |
1206 | default_pp($op); |
1207 | my $redoop = $cxstack[$cxix]->{redoop}; |
1208 | push(@bblock_todo, $redoop); |
1209 | runtime(sprintf("goto %s;", label($redoop))); |
1210 | return $op->next; |
1211 | } |
1212 | |
1213 | sub pp_last { |
1214 | my $op = shift; |
1215 | my $cxix; |
1216 | if ($op->flags & OPf_SPECIAL) { |
1217 | $cxix = dopoptoloop(); |
1218 | if ($cxix < 0) { |
1219 | error('"last" used outside loop'); |
1220 | return $op->next; # ignore the op |
1221 | } |
1222 | } else { |
1223 | $cxix = dopoptolabel($op->pv); |
1224 | if ($cxix < 0) { |
1225 | error('Label not found at compile time for "last %s"', $op->pv); |
1226 | return $op->next; # ignore the op |
1227 | } |
1228 | # XXX Add support for "last" to leave non-loop blocks |
1229 | if ($cxstack[$cxix]->{type} != CXt_LOOP) { |
1230 | error('Use of "last" for non-loop blocks is not yet implemented'); |
1231 | return $op->next; # ignore the op |
1232 | } |
1233 | } |
1234 | default_pp($op); |
1235 | my $lastop = $cxstack[$cxix]->{lastop}->next; |
1236 | push(@bblock_todo, $lastop); |
1237 | runtime(sprintf("goto %s;", label($lastop))); |
1238 | return $op->next; |
1239 | } |
1240 | |
1241 | sub pp_subst { |
1242 | my $op = shift; |
1243 | write_back_lexicals(); |
1244 | write_back_stack(); |
1245 | my $sym = doop($op); |
1246 | my $replroot = $op->pmreplroot; |
1247 | if ($$replroot) { |
81009501 |
1248 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplroot) goto %s;", |
a798dbf2 |
1249 | $sym, label($replroot)); |
1250 | $op->pmreplstart->save; |
1251 | push(@bblock_todo, $replroot); |
1252 | } |
1253 | invalidate_lexicals(); |
1254 | return $op->next; |
1255 | } |
1256 | |
1257 | sub pp_substcont { |
1258 | my $op = shift; |
1259 | write_back_lexicals(); |
1260 | write_back_stack(); |
1261 | doop($op); |
1262 | my $pmop = $op->other; |
0cc1d052 |
1263 | # warn sprintf("substcont: op = %s, pmop = %s\n", |
1264 | # peekop($op), peekop($pmop));#debug |
1265 | # my $pmopsym = objsym($pmop); |
a798dbf2 |
1266 | my $pmopsym = $pmop->save; # XXX can this recurse? |
0cc1d052 |
1267 | # warn "pmopsym = $pmopsym\n";#debug |
81009501 |
1268 | runtime sprintf("if (PL_op == ((PMOP*)(%s))->op_pmreplstart) goto %s;", |
a798dbf2 |
1269 | $pmopsym, label($pmop->pmreplstart)); |
1270 | invalidate_lexicals(); |
1271 | return $pmop->next; |
1272 | } |
1273 | |
1274 | sub default_pp { |
1275 | my $op = shift; |
1276 | my $ppname = $op->ppaddr; |
1277 | write_back_lexicals() unless $skip_lexicals{$ppname}; |
1278 | write_back_stack() unless $skip_stack{$ppname}; |
1279 | doop($op); |
1280 | # XXX If the only way that ops can write to a TEMPORARY lexical is |
1281 | # when it's named in $op->targ then we could call |
1282 | # invalidate_lexicals(TEMPORARY) and avoid having to write back all |
1283 | # the temporaries. For now, we'll play it safe and write back the lot. |
1284 | invalidate_lexicals() unless $skip_invalidate{$ppname}; |
1285 | return $op->next; |
1286 | } |
1287 | |
1288 | sub compile_op { |
1289 | my $op = shift; |
1290 | my $ppname = $op->ppaddr; |
1291 | if (exists $ignore_op{$ppname}) { |
1292 | return $op->next; |
1293 | } |
1294 | debug peek_stack() if $debug_stack; |
1295 | if ($debug_op) { |
1296 | debug sprintf("%s [%s]\n", |
1297 | peekop($op), |
1298 | $op->flags & OPf_STACKED ? "OPf_STACKED" : $op->targ); |
1299 | } |
1300 | no strict 'refs'; |
1301 | if (defined(&$ppname)) { |
1302 | $know_op = 0; |
1303 | return &$ppname($op); |
1304 | } else { |
1305 | return default_pp($op); |
1306 | } |
1307 | } |
1308 | |
1309 | sub compile_bblock { |
1310 | my $op = shift; |
1311 | #warn "compile_bblock: ", peekop($op), "\n"; # debug |
1312 | write_label($op); |
1313 | $know_op = 0; |
1314 | do { |
1315 | $op = compile_op($op); |
1316 | } while (defined($op) && $$op && !exists($leaders->{$$op})); |
1317 | write_back_stack(); # boo hoo: big loss |
1318 | reload_lexicals(); |
1319 | return $op; |
1320 | } |
1321 | |
1322 | sub cc { |
1323 | my ($name, $root, $start, @padlist) = @_; |
1324 | my $op; |
1325 | init_pp($name); |
1326 | load_pad(@padlist); |
1327 | B::Pseudoreg->new_scope; |
1328 | @cxstack = (); |
1329 | if ($debug_timings) { |
1330 | warn sprintf("Basic block analysis at %s\n", timing_info); |
1331 | } |
1332 | $leaders = find_leaders($root, $start); |
1333 | @bblock_todo = ($start, values %$leaders); |
1334 | if ($debug_timings) { |
1335 | warn sprintf("Compilation at %s\n", timing_info); |
1336 | } |
1337 | while (@bblock_todo) { |
1338 | $op = shift @bblock_todo; |
1339 | #warn sprintf("Considering basic block %s\n", peekop($op)); # debug |
1340 | next if !defined($op) || !$$op || $done{$$op}; |
1341 | #warn "...compiling it\n"; # debug |
1342 | do { |
1343 | $done{$$op} = 1; |
1344 | $op = compile_bblock($op); |
1345 | if ($need_freetmps && $freetmps_each_bblock) { |
1346 | runtime("FREETMPS;"); |
1347 | $need_freetmps = 0; |
1348 | } |
1349 | } while defined($op) && $$op && !$done{$$op}; |
1350 | if ($need_freetmps && $freetmps_each_loop) { |
1351 | runtime("FREETMPS;"); |
1352 | $need_freetmps = 0; |
1353 | } |
1354 | if (!$$op) { |
7dbaefaf |
1355 | runtime("PUTBACK;","return PL_op;"); |
a798dbf2 |
1356 | } elsif ($done{$$op}) { |
1357 | runtime(sprintf("goto %s;", label($op))); |
1358 | } |
1359 | } |
1360 | if ($debug_timings) { |
1361 | warn sprintf("Saving runtime at %s\n", timing_info); |
1362 | } |
1363 | save_runtime(); |
1364 | } |
1365 | |
1366 | sub cc_recurse { |
1367 | my $ccinfo; |
1368 | my $start; |
1369 | $start = cc_queue(@_) if @_; |
1370 | while ($ccinfo = shift @cc_todo) { |
1371 | cc(@$ccinfo); |
1372 | } |
1373 | return $start; |
1374 | } |
1375 | |
1376 | sub cc_obj { |
1377 | my ($name, $cvref) = @_; |
1378 | my $cv = svref_2object($cvref); |
1379 | my @padlist = $cv->PADLIST->ARRAY; |
1380 | my $curpad_sym = $padlist[1]->save; |
1381 | cc_recurse($name, $cv->ROOT, $cv->START, @padlist); |
1382 | } |
1383 | |
1384 | sub cc_main { |
1385 | my @comppadlist = comppadlist->ARRAY; |
0cc1d052 |
1386 | my $curpad_nam = $comppadlist[0]->save; |
1387 | my $curpad_sym = $comppadlist[1]->save; |
1388 | my $init_av = init_av->save; |
1389 | my $inc_hv = svref_2object(\%INC)->save; |
1390 | my $inc_av = svref_2object(\@INC)->save; |
a798dbf2 |
1391 | my $start = cc_recurse("pp_main", main_root, main_start, @comppadlist); |
0cc1d052 |
1392 | save_unused_subs(); |
a798dbf2 |
1393 | cc_recurse(); |
1394 | |
1395 | return if $errors; |
1396 | if (!defined($module)) { |
81009501 |
1397 | $init->add(sprintf("PL_main_root = s\\_%x;", ${main_root()}), |
1398 | "PL_main_start = $start;", |
5cfd8ad4 |
1399 | "PL_curpad = AvARRAY($curpad_sym);", |
0cc1d052 |
1400 | "PL_initav = $init_av;", |
1401 | "GvHV(PL_incgv) = $inc_hv;", |
1402 | "GvAV(PL_incgv) = $inc_av;", |
5cfd8ad4 |
1403 | "av_store(CvPADLIST(PL_main_cv),0,SvREFCNT_inc($curpad_nam));", |
44887cfa |
1404 | "av_store(CvPADLIST(PL_main_cv),1,SvREFCNT_inc($curpad_sym));", |
1405 | ); |
1406 | |
a798dbf2 |
1407 | } |
1408 | output_boilerplate(); |
1409 | print "\n"; |
1410 | output_all("perl_init"); |
1411 | output_runtime(); |
1412 | print "\n"; |
1413 | output_main(); |
1414 | if (defined($module)) { |
1415 | my $cmodule = $module; |
1416 | $cmodule =~ s/::/__/g; |
1417 | print <<"EOT"; |
1418 | |
1419 | #include "XSUB.h" |
1420 | XS(boot_$cmodule) |
1421 | { |
1422 | dXSARGS; |
1423 | perl_init(); |
1424 | ENTER; |
1425 | SAVETMPS; |
81009501 |
1426 | SAVESPTR(PL_curpad); |
1427 | SAVESPTR(PL_op); |
1428 | PL_curpad = AvARRAY($curpad_sym); |
1429 | PL_op = $start; |
a798dbf2 |
1430 | pp_main(ARGS); |
1431 | FREETMPS; |
1432 | LEAVE; |
81009501 |
1433 | ST(0) = &PL_sv_yes; |
a798dbf2 |
1434 | XSRETURN(1); |
1435 | } |
1436 | EOT |
1437 | } |
1438 | if ($debug_timings) { |
1439 | warn sprintf("Done at %s\n", timing_info); |
1440 | } |
1441 | } |
1442 | |
1443 | sub compile { |
1444 | my @options = @_; |
1445 | my ($option, $opt, $arg); |
1446 | OPTION: |
1447 | while ($option = shift @options) { |
1448 | if ($option =~ /^-(.)(.*)/) { |
1449 | $opt = $1; |
1450 | $arg = $2; |
1451 | } else { |
1452 | unshift @options, $option; |
1453 | last OPTION; |
1454 | } |
1455 | if ($opt eq "-" && $arg eq "-") { |
1456 | shift @options; |
1457 | last OPTION; |
1458 | } elsif ($opt eq "o") { |
1459 | $arg ||= shift @options; |
ff06c60c |
1460 | open(STDOUT, ">$arg") or return "open '>$arg': $!\n"; |
a798dbf2 |
1461 | } elsif ($opt eq "n") { |
1462 | $arg ||= shift @options; |
1463 | $module_name = $arg; |
1464 | } elsif ($opt eq "u") { |
1465 | $arg ||= shift @options; |
0cc1d052 |
1466 | mark_unused($arg,undef); |
a798dbf2 |
1467 | } elsif ($opt eq "f") { |
1468 | $arg ||= shift @options; |
1469 | my $value = $arg !~ s/^no-//; |
1470 | $arg =~ s/-/_/g; |
1471 | my $ref = $optimise{$arg}; |
1472 | if (defined($ref)) { |
1473 | $$ref = $value; |
1474 | } else { |
1475 | warn qq(ignoring unknown optimisation option "$arg"\n); |
1476 | } |
1477 | } elsif ($opt eq "O") { |
1478 | $arg = 1 if $arg eq ""; |
1479 | my $ref; |
1480 | foreach $ref (values %optimise) { |
1481 | $$ref = 0; |
1482 | } |
1483 | if ($arg >= 2) { |
1484 | $freetmps_each_loop = 1; |
1485 | } |
1486 | if ($arg >= 1) { |
1487 | $freetmps_each_bblock = 1 unless $freetmps_each_loop; |
1488 | } |
1489 | } elsif ($opt eq "m") { |
1490 | $arg ||= shift @options; |
1491 | $module = $arg; |
ff144d38 |
1492 | mark_unused($arg,undef); |
a798dbf2 |
1493 | } elsif ($opt eq "p") { |
1494 | $arg ||= shift @options; |
1495 | $patchlevel = $arg; |
1496 | } elsif ($opt eq "D") { |
1497 | $arg ||= shift @options; |
1498 | foreach $arg (split(//, $arg)) { |
1499 | if ($arg eq "o") { |
1500 | B->debug(1); |
1501 | } elsif ($arg eq "O") { |
1502 | $debug_op = 1; |
1503 | } elsif ($arg eq "s") { |
1504 | $debug_stack = 1; |
1505 | } elsif ($arg eq "c") { |
1506 | $debug_cxstack = 1; |
1507 | } elsif ($arg eq "p") { |
1508 | $debug_pad = 1; |
1509 | } elsif ($arg eq "r") { |
1510 | $debug_runtime = 1; |
1511 | } elsif ($arg eq "S") { |
1512 | $debug_shadow = 1; |
1513 | } elsif ($arg eq "q") { |
1514 | $debug_queue = 1; |
1515 | } elsif ($arg eq "l") { |
1516 | $debug_lineno = 1; |
1517 | } elsif ($arg eq "t") { |
1518 | $debug_timings = 1; |
1519 | } |
1520 | } |
1521 | } |
1522 | } |
1523 | init_sections(); |
1524 | $init = B::Section->get("init"); |
1525 | $decl = B::Section->get("decl"); |
1526 | |
1527 | if (@options) { |
1528 | return sub { |
1529 | my ($objname, $ppname); |
1530 | foreach $objname (@options) { |
1531 | $objname = "main::$objname" unless $objname =~ /::/; |
1532 | ($ppname = $objname) =~ s/^.*?:://; |
1533 | eval "cc_obj(qq(pp_sub_$ppname), \\&$objname)"; |
1534 | die "cc_obj(qq(pp_sub_$ppname, \\&$objname) failed: $@" if $@; |
1535 | return if $errors; |
1536 | } |
1537 | output_boilerplate(); |
1538 | print "\n"; |
1539 | output_all($module_name || "init_module"); |
1540 | output_runtime(); |
1541 | } |
1542 | } else { |
1543 | return sub { cc_main() }; |
1544 | } |
1545 | } |
1546 | |
1547 | 1; |
7f20e9dd |
1548 | |
1549 | __END__ |
1550 | |
1551 | =head1 NAME |
1552 | |
1553 | B::CC - Perl compiler's optimized C translation backend |
1554 | |
1555 | =head1 SYNOPSIS |
1556 | |
1557 | perl -MO=CC[,OPTIONS] foo.pl |
1558 | |
1559 | =head1 DESCRIPTION |
1560 | |
1a52ab62 |
1561 | This compiler backend takes Perl source and generates C source code |
1562 | corresponding to the flow of your program. In other words, this |
1563 | backend is somewhat a "real" compiler in the sense that many people |
1564 | think about compilers. Note however that, currently, it is a very |
1565 | poor compiler in that although it generates (mostly, or at least |
1566 | sometimes) correct code, it performs relatively few optimisations. |
1567 | This will change as the compiler develops. The result is that |
1568 | running an executable compiled with this backend may start up more |
1569 | quickly than running the original Perl program (a feature shared |
1570 | by the B<C> compiler backend--see F<B::C>) and may also execute |
1571 | slightly faster. This is by no means a good optimising compiler--yet. |
1572 | |
1573 | =head1 OPTIONS |
1574 | |
1575 | If there are any non-option arguments, they are taken to be |
1576 | names of objects to be saved (probably doesn't work properly yet). |
1577 | Without extra arguments, it saves the main program. |
1578 | |
1579 | =over 4 |
1580 | |
1581 | =item B<-ofilename> |
1582 | |
1583 | Output to filename instead of STDOUT |
1584 | |
1585 | =item B<-v> |
1586 | |
1587 | Verbose compilation (currently gives a few compilation statistics). |
1588 | |
1589 | =item B<--> |
1590 | |
1591 | Force end of options |
1592 | |
1593 | =item B<-uPackname> |
1594 | |
1595 | Force apparently unused subs from package Packname to be compiled. |
1596 | This allows programs to use eval "foo()" even when sub foo is never |
1597 | seen to be used at compile time. The down side is that any subs which |
1598 | really are never used also have code generated. This option is |
1599 | necessary, for example, if you have a signal handler foo which you |
1600 | initialise with C<$SIG{BAR} = "foo">. A better fix, though, is just |
1601 | to change it to C<$SIG{BAR} = \&foo>. You can have multiple B<-u> |
1602 | options. The compiler tries to figure out which packages may possibly |
1603 | have subs in which need compiling but the current version doesn't do |
1604 | it very well. In particular, it is confused by nested packages (i.e. |
1605 | of the form C<A::B>) where package C<A> does not contain any subs. |
1606 | |
1607 | =item B<-mModulename> |
1608 | |
1609 | Instead of generating source for a runnable executable, generate |
1610 | source for an XSUB module. The boot_Modulename function (which |
1611 | DynaLoader can look for) does the appropriate initialisation and runs |
1612 | the main part of the Perl source that is being compiled. |
1613 | |
1614 | |
1615 | =item B<-D> |
1616 | |
1617 | Debug options (concatenated or separate flags like C<perl -D>). |
1618 | |
1619 | =item B<-Dr> |
1620 | |
1621 | Writes debugging output to STDERR just as it's about to write to the |
1622 | program's runtime (otherwise writes debugging info as comments in |
1623 | its C output). |
1624 | |
1625 | =item B<-DO> |
1626 | |
1627 | Outputs each OP as it's compiled |
1628 | |
1629 | =item B<-Ds> |
1630 | |
1631 | Outputs the contents of the shadow stack at each OP |
1632 | |
1633 | =item B<-Dp> |
1634 | |
1635 | Outputs the contents of the shadow pad of lexicals as it's loaded for |
1636 | each sub or the main program. |
1637 | |
1638 | =item B<-Dq> |
1639 | |
1640 | Outputs the name of each fake PP function in the queue as it's about |
1641 | to process it. |
1642 | |
1643 | =item B<-Dl> |
1644 | |
1645 | Output the filename and line number of each original line of Perl |
1646 | code as it's processed (C<pp_nextstate>). |
1647 | |
1648 | =item B<-Dt> |
1649 | |
1650 | Outputs timing information of compilation stages. |
1651 | |
1652 | =item B<-f> |
1653 | |
1654 | Force optimisations on or off one at a time. |
1655 | |
1656 | =item B<-ffreetmps-each-bblock> |
1657 | |
1658 | Delays FREETMPS from the end of each statement to the end of the each |
1659 | basic block. |
1660 | |
1661 | =item B<-ffreetmps-each-loop> |
1662 | |
1663 | Delays FREETMPS from the end of each statement to the end of the group |
1664 | of basic blocks forming a loop. At most one of the freetmps-each-* |
1665 | options can be used. |
1666 | |
1667 | =item B<-fomit-taint> |
1668 | |
1669 | Omits generating code for handling perl's tainting mechanism. |
1670 | |
1671 | =item B<-On> |
1672 | |
1673 | Optimisation level (n = 0, 1, 2, ...). B<-O> means B<-O1>. |
1674 | Currently, B<-O1> sets B<-ffreetmps-each-bblock> and B<-O2> |
1675 | sets B<-ffreetmps-each-loop>. |
1676 | |
1677 | =back |
1678 | |
1679 | =head1 EXAMPLES |
1680 | |
1681 | perl -MO=CC,-O2,-ofoo.c foo.pl |
1682 | perl cc_harness -o foo foo.c |
1683 | |
1684 | Note that C<cc_harness> lives in the C<B> subdirectory of your perl |
1685 | library directory. The utility called C<perlcc> may also be used to |
1686 | help make use of this compiler. |
1687 | |
1688 | perl -MO=CC,-mFoo,-oFoo.c Foo.pm |
1689 | perl cc_harness -shared -c -o Foo.so Foo.c |
1690 | |
1691 | =head1 BUGS |
1692 | |
1693 | Plenty. Current status: experimental. |
1694 | |
1695 | =head1 DIFFERENCES |
1696 | |
1697 | These aren't really bugs but they are constructs which are heavily |
1698 | tied to perl's compile-and-go implementation and with which this |
1699 | compiler backend cannot cope. |
1700 | |
1701 | =head2 Loops |
1702 | |
1703 | Standard perl calculates the target of "next", "last", and "redo" |
1704 | at run-time. The compiler calculates the targets at compile-time. |
1705 | For example, the program |
1706 | |
1707 | sub skip_on_odd { next NUMBER if $_[0] % 2 } |
1708 | NUMBER: for ($i = 0; $i < 5; $i++) { |
1709 | skip_on_odd($i); |
1710 | print $i; |
1711 | } |
1712 | |
1713 | produces the output |
1714 | |
1715 | 024 |
1716 | |
1717 | with standard perl but gives a compile-time error with the compiler. |
1718 | |
1719 | =head2 Context of ".." |
1720 | |
1721 | The context (scalar or array) of the ".." operator determines whether |
1722 | it behaves as a range or a flip/flop. Standard perl delays until |
1723 | runtime the decision of which context it is in but the compiler needs |
1724 | to know the context at compile-time. For example, |
1725 | |
1726 | @a = (4,6,1,0,0,1); |
1727 | sub range { (shift @a)..(shift @a) } |
1728 | print range(); |
1729 | while (@a) { print scalar(range()) } |
1730 | |
1731 | generates the output |
1732 | |
1733 | 456123E0 |
1734 | |
1735 | with standard Perl but gives a compile-time error with compiled Perl. |
1736 | |
1737 | =head2 Arithmetic |
1738 | |
1739 | Compiled Perl programs use native C arithemtic much more frequently |
1740 | than standard perl. Operations on large numbers or on boundary |
1741 | cases may produce different behaviour. |
1742 | |
1743 | =head2 Deprecated features |
1744 | |
1745 | Features of standard perl such as C<$[> which have been deprecated |
1746 | in standard perl since Perl5 was released have not been implemented |
1747 | in the compiler. |
7f20e9dd |
1748 | |
1749 | =head1 AUTHOR |
1750 | |
1751 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
1752 | |
1753 | =cut |