source: vendor/perl/5.8.8/universal.c

Last change on this file was 3181, checked in by bird, 18 years ago

perl 5.8.8
File size: 16.2 KB
RevLine 
[3181]1/* universal.c
2 *
3 * Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4 * 2005, 2006, by Larry Wall and others
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
11/*
12 * "The roots of those mountains must be roots indeed; there must be
13 * great secrets buried there which have not been discovered since the
14 * beginning." --Gandalf, relating Gollum's story
15 */
16
17/* This file contains the code that implements the functions in Perl's
18 * UNIVERSAL package, such as UNIVERSAL->can().
19 */
20
21#include "EXTERN.h"
22#define PERL_IN_UNIVERSAL_C
23#include "perl.h"
24
25#ifdef USE_PERLIO
26#include "perliol.h" /* For the PERLIO_F_XXX */
27#endif
28
29/*
30 * Contributed by Graham Barr <Graham.Barr@tiuk.ti.com>
31 * The main guts of traverse_isa was actually copied from gv_fetchmeth
32 */
33
34STATIC SV *
35S_isa_lookup(pTHX_ HV *stash, const char *name, HV* name_stash,
36 int len, int level)
37{
38 AV* av;
39 GV* gv;
40 GV** gvp;
41 HV* hv = Nullhv;
42 SV* subgen = Nullsv;
43 const char *hvname;
44
45 /* A stash/class can go by many names (ie. User == main::User), so
46 we compare the stash itself just in case */
47 if (name_stash && (stash == name_stash))
48 return &PL_sv_yes;
49
50 hvname = HvNAME_get(stash);
51
52 if (strEQ(hvname, name))
53 return &PL_sv_yes;
54
55 if (strEQ(name, "UNIVERSAL"))
56 return &PL_sv_yes;
57
58 if (level > 100)
59 Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
60 hvname);
61
62 gvp = (GV**)hv_fetch(stash, "::ISA::CACHE::", 14, FALSE);
63
64 if (gvp && (gv = *gvp) != (GV*)&PL_sv_undef && (subgen = GvSV(gv))
65 && (hv = GvHV(gv)))
66 {
67 if (SvIV(subgen) == (IV)PL_sub_generation) {
68 SV* sv;
69 SV** svp = (SV**)hv_fetch(hv, name, len, FALSE);
70 if (svp && (sv = *svp) != (SV*)&PL_sv_undef) {
71 DEBUG_o( Perl_deb(aTHX_ "Using cached ISA %s for package %s\n",
72 name, hvname) );
73 return sv;
74 }
75 }
76 else {
77 DEBUG_o( Perl_deb(aTHX_ "ISA Cache in package %s is stale\n",
78 hvname) );
79 hv_clear(hv);
80 sv_setiv(subgen, PL_sub_generation);
81 }
82 }
83
84 gvp = (GV**)hv_fetch(stash,"ISA",3,FALSE);
85
86 if (gvp && (gv = *gvp) != (GV*)&PL_sv_undef && (av = GvAV(gv))) {
87 if (!hv || !subgen) {
88 gvp = (GV**)hv_fetch(stash, "::ISA::CACHE::", 14, TRUE);
89
90 gv = *gvp;
91
92 if (SvTYPE(gv) != SVt_PVGV)
93 gv_init(gv, stash, "::ISA::CACHE::", 14, TRUE);
94
95 if (!hv)
96 hv = GvHVn(gv);
97 if (!subgen) {
98 subgen = newSViv(PL_sub_generation);
99 GvSV(gv) = subgen;
100 }
101 }
102 if (hv) {
103 SV** svp = AvARRAY(av);
104 /* NOTE: No support for tied ISA */
105 I32 items = AvFILLp(av) + 1;
106 while (items--) {
107 SV* sv = *svp++;
108 HV* basestash = gv_stashsv(sv, FALSE);
109 if (!basestash) {
110 if (ckWARN(WARN_MISC))
111 Perl_warner(aTHX_ packWARN(WARN_SYNTAX),
112 "Can't locate package %"SVf" for @%s::ISA",
113 sv, hvname);
114 continue;
115 }
116 if (&PL_sv_yes == isa_lookup(basestash, name, name_stash,
117 len, level + 1)) {
118 (void)hv_store(hv,name,len,&PL_sv_yes,0);
119 return &PL_sv_yes;
120 }
121 }
122 (void)hv_store(hv,name,len,&PL_sv_no,0);
123 }
124 }
125 return &PL_sv_no;
126}
127
128/*
129=head1 SV Manipulation Functions
130
131=for apidoc sv_derived_from
132
133Returns a boolean indicating whether the SV is derived from the specified
134class. This is the function that implements C<UNIVERSAL::isa>. It works
135for class names as well as for objects.
136
137=cut
138*/
139
140bool
141Perl_sv_derived_from(pTHX_ SV *sv, const char *name)
142{
143 const char *type = Nullch;
144 HV *stash = Nullhv;
145 HV *name_stash;
146
147 if (SvGMAGICAL(sv))
148 mg_get(sv) ;
149
150 if (SvROK(sv)) {
151 sv = SvRV(sv);
152 type = sv_reftype(sv,0);
153 if (SvOBJECT(sv))
154 stash = SvSTASH(sv);
155 }
156 else {
157 stash = gv_stashsv(sv, FALSE);
158 }
159
160 name_stash = gv_stashpv(name, FALSE);
161
162 return (type && strEQ(type,name)) ||
163 (stash && isa_lookup(stash, name, name_stash, strlen(name), 0)
164 == &PL_sv_yes)
165 ? TRUE
166 : FALSE ;
167}
168
169#include "XSUB.h"
170
171PERL_XS_EXPORT_C void XS_UNIVERSAL_isa(pTHX_ CV *cv);
172PERL_XS_EXPORT_C void XS_UNIVERSAL_can(pTHX_ CV *cv);
173PERL_XS_EXPORT_C void XS_UNIVERSAL_VERSION(pTHX_ CV *cv);
174XS(XS_utf8_is_utf8);
175XS(XS_utf8_valid);
176XS(XS_utf8_encode);
177XS(XS_utf8_decode);
178XS(XS_utf8_upgrade);
179XS(XS_utf8_downgrade);
180XS(XS_utf8_unicode_to_native);
181XS(XS_utf8_native_to_unicode);
182XS(XS_Internals_SvREADONLY);
183XS(XS_Internals_SvREFCNT);
184XS(XS_Internals_hv_clear_placehold);
185XS(XS_PerlIO_get_layers);
186XS(XS_Regexp_DESTROY);
187XS(XS_Internals_hash_seed);
188XS(XS_Internals_rehash_seed);
189XS(XS_Internals_HvREHASH);
190
191void
192Perl_boot_core_UNIVERSAL(pTHX)
193{
194 const char file[] = __FILE__;
195
196 newXS("UNIVERSAL::isa", XS_UNIVERSAL_isa, (char *)file);
197 newXS("UNIVERSAL::can", XS_UNIVERSAL_can, (char *)file);
198 newXS("UNIVERSAL::VERSION", XS_UNIVERSAL_VERSION, (char *)file);
199 newXS("utf8::is_utf8", XS_utf8_is_utf8, (char *)file);
200 newXS("utf8::valid", XS_utf8_valid, (char *)file);
201 newXS("utf8::encode", XS_utf8_encode, (char *)file);
202 newXS("utf8::decode", XS_utf8_decode, (char *)file);
203 newXS("utf8::upgrade", XS_utf8_upgrade, (char *)file);
204 newXS("utf8::downgrade", XS_utf8_downgrade, (char *)file);
205 newXS("utf8::native_to_unicode", XS_utf8_native_to_unicode, (char *)file);
206 newXS("utf8::unicode_to_native", XS_utf8_unicode_to_native, (char *)file);
207 newXSproto("Internals::SvREADONLY",XS_Internals_SvREADONLY, (char *)file, "\\[$%@];$");
208 newXSproto("Internals::SvREFCNT",XS_Internals_SvREFCNT, (char *)file, "\\[$%@];$");
209 newXSproto("Internals::hv_clear_placeholders",
210 XS_Internals_hv_clear_placehold, (char *)file, "\\%");
211 newXSproto("PerlIO::get_layers",
212 XS_PerlIO_get_layers, (char *)file, "*;@");
213 newXS("Regexp::DESTROY", XS_Regexp_DESTROY, (char *)file);
214 newXSproto("Internals::hash_seed",XS_Internals_hash_seed, (char *)file, "");
215 newXSproto("Internals::rehash_seed",XS_Internals_rehash_seed, (char *)file, "");
216 newXSproto("Internals::HvREHASH", XS_Internals_HvREHASH, (char *)file, "\\%");
217}
218
219
220XS(XS_UNIVERSAL_isa)
221{
222 dXSARGS;
223 SV *sv;
224 const char *name;
225
226 if (items != 2)
227 Perl_croak(aTHX_ "Usage: UNIVERSAL::isa(reference, kind)");
228
229 sv = ST(0);
230
231 if (SvGMAGICAL(sv))
232 mg_get(sv);
233
234 if (!SvOK(sv) || !(SvROK(sv) || (SvPOK(sv) && SvCUR(sv))
235 || (SvGMAGICAL(sv) && SvPOKp(sv) && SvCUR(sv))))
236 XSRETURN_UNDEF;
237
238 name = SvPV_nolen_const(ST(1));
239
240 ST(0) = boolSV(sv_derived_from(sv, name));
241 XSRETURN(1);
242}
243
244XS(XS_UNIVERSAL_can)
245{
246 dXSARGS;
247 SV *sv;
248 const char *name;
249 SV *rv;
250 HV *pkg = NULL;
251
252 if (items != 2)
253 Perl_croak(aTHX_ "Usage: UNIVERSAL::can(object-ref, method)");
254
255 sv = ST(0);
256
257 if (SvGMAGICAL(sv))
258 mg_get(sv);
259
260 if (!SvOK(sv) || !(SvROK(sv) || (SvPOK(sv) && SvCUR(sv))
261 || (SvGMAGICAL(sv) && SvPOKp(sv) && SvCUR(sv))))
262 XSRETURN_UNDEF;
263
264 name = SvPV_nolen_const(ST(1));
265 rv = &PL_sv_undef;
266
267 if (SvROK(sv)) {
268 sv = (SV*)SvRV(sv);
269 if (SvOBJECT(sv))
270 pkg = SvSTASH(sv);
271 }
272 else {
273 pkg = gv_stashsv(sv, FALSE);
274 }
275
276 if (pkg) {
277 GV *gv = gv_fetchmethod_autoload(pkg, name, FALSE);
278 if (gv && isGV(gv))
279 rv = sv_2mortal(newRV((SV*)GvCV(gv)));
280 }
281
282 ST(0) = rv;
283 XSRETURN(1);
284}
285
286XS(XS_UNIVERSAL_VERSION)
287{
288 dXSARGS;
289 HV *pkg;
290 GV **gvp;
291 GV *gv;
292 SV *sv;
293 const char *undef;
294
295 if (SvROK(ST(0))) {
296 sv = (SV*)SvRV(ST(0));
297 if (!SvOBJECT(sv))
298 Perl_croak(aTHX_ "Cannot find version of an unblessed reference");
299 pkg = SvSTASH(sv);
300 }
301 else {
302 pkg = gv_stashsv(ST(0), FALSE);
303 }
304
305 gvp = pkg ? (GV**)hv_fetch(pkg,"VERSION",7,FALSE) : Null(GV**);
306
307 if (gvp && isGV(gv = *gvp) && (sv = GvSV(gv)) && SvOK(sv)) {
308 SV *nsv = sv_newmortal();
309 sv_setsv(nsv, sv);
310 sv = nsv;
311 undef = Nullch;
312 }
313 else {
314 sv = (SV*)&PL_sv_undef;
315 undef = "(undef)";
316 }
317
318 if (items > 1) {
319 SV *req = ST(1);
320
321 if (undef) {
322 if (pkg) {
323 const char *name = HvNAME_get(pkg);
324 Perl_croak(aTHX_
325 "%s does not define $%s::VERSION--version check failed",
326 name, name);
327 } else {
328 Perl_croak(aTHX_
329 "%s defines neither package nor VERSION--version check failed",
330 SvPVx_nolen_const(ST(0)) );
331 }
332 }
333 if (!SvNIOK(sv) && SvPOK(sv)) {
334 STRLEN len;
335 char *str = SvPVx(sv,len);
336 while (len) {
337 --len;
338 /* XXX could DWIM "1.2.3" here */
339 if (!isDIGIT(str[len]) && str[len] != '.' && str[len] != '_')
340 break;
341 }
342 if (len) {
343 if (SvNOK(req) && SvPOK(req)) {
344 /* they said C<use Foo v1.2.3> and $Foo::VERSION
345 * doesn't look like a float: do string compare */
346 if (sv_cmp(req,sv) == 1) {
347 Perl_croak(aTHX_ "%s v%"VDf" required--"
348 "this is only v%"VDf,
349 HvNAME(pkg), req, sv);
350 }
351 goto finish;
352 }
353 /* they said C<use Foo 1.002_003> and $Foo::VERSION
354 * doesn't look like a float: force numeric compare */
355 (void)SvUPGRADE(sv, SVt_PVNV);
356 SvNVX(sv) = str_to_version(sv);
357 SvPOK_off(sv);
358 SvNOK_on(sv);
359 }
360 }
361 /* if we get here, we're looking for a numeric comparison,
362 * so force the required version into a float, even if they
363 * said C<use Foo v1.2.3> */
364 if (SvNOK(req) && SvPOK(req)) {
365 NV n = SvNV(req);
366 req = sv_newmortal();
367 sv_setnv(req, n);
368 }
369
370 if (SvNV(req) > SvNV(sv))
371 Perl_croak(aTHX_ "%s version %s required--this is only version %s",
372 HvNAME_get(pkg), SvPV_nolen(req), SvPV_nolen(sv));
373 }
374
375finish:
376 ST(0) = sv;
377
378 XSRETURN(1);
379}
380
381XS(XS_utf8_is_utf8)
382{
383 dXSARGS;
384 if (items != 1)
385 Perl_croak(aTHX_ "Usage: utf8::is_utf8(sv)");
386 {
387 const SV *sv = ST(0);
388 {
389 if (SvUTF8(sv))
390 XSRETURN_YES;
391 else
392 XSRETURN_NO;
393 }
394 }
395 XSRETURN_EMPTY;
396}
397
398XS(XS_utf8_valid)
399{
400 dXSARGS;
401 if (items != 1)
402 Perl_croak(aTHX_ "Usage: utf8::valid(sv)");
403 {
404 SV * sv = ST(0);
405 {
406 STRLEN len;
407 const char *s = SvPV_const(sv,len);
408 if (!SvUTF8(sv) || is_utf8_string((U8*)s,len))
409 XSRETURN_YES;
410 else
411 XSRETURN_NO;
412 }
413 }
414 XSRETURN_EMPTY;
415}
416
417XS(XS_utf8_encode)
418{
419 dXSARGS;
420 if (items != 1)
421 Perl_croak(aTHX_ "Usage: utf8::encode(sv)");
422 {
423 SV * sv = ST(0);
424
425 sv_utf8_encode(sv);
426 }
427 XSRETURN_EMPTY;
428}
429
430XS(XS_utf8_decode)
431{
432 dXSARGS;
433 if (items != 1)
434 Perl_croak(aTHX_ "Usage: utf8::decode(sv)");
435 {
436 SV * sv = ST(0);
437 const bool RETVAL = sv_utf8_decode(sv);
438 ST(0) = boolSV(RETVAL);
439 sv_2mortal(ST(0));
440 }
441 XSRETURN(1);
442}
443
444XS(XS_utf8_upgrade)
445{
446 dXSARGS;
447 if (items != 1)
448 Perl_croak(aTHX_ "Usage: utf8::upgrade(sv)");
449 {
450 SV * sv = ST(0);
451 STRLEN RETVAL;
452 dXSTARG;
453
454 RETVAL = sv_utf8_upgrade(sv);
455 XSprePUSH; PUSHi((IV)RETVAL);
456 }
457 XSRETURN(1);
458}
459
460XS(XS_utf8_downgrade)
461{
462 dXSARGS;
463 if (items < 1 || items > 2)
464 Perl_croak(aTHX_ "Usage: utf8::downgrade(sv, failok=0)");
465 {
466 SV * sv = ST(0);
467 const bool failok = (items < 2) ? 0 : (int)SvIV(ST(1));
468 const bool RETVAL = sv_utf8_downgrade(sv, failok);
469
470 ST(0) = boolSV(RETVAL);
471 sv_2mortal(ST(0));
472 }
473 XSRETURN(1);
474}
475
476XS(XS_utf8_native_to_unicode)
477{
478 dXSARGS;
479 const UV uv = SvUV(ST(0));
480
481 if (items > 1)
482 Perl_croak(aTHX_ "Usage: utf8::native_to_unicode(sv)");
483
484 ST(0) = sv_2mortal(newSViv(NATIVE_TO_UNI(uv)));
485 XSRETURN(1);
486}
487
488XS(XS_utf8_unicode_to_native)
489{
490 dXSARGS;
491 const UV uv = SvUV(ST(0));
492
493 if (items > 1)
494 Perl_croak(aTHX_ "Usage: utf8::unicode_to_native(sv)");
495
496 ST(0) = sv_2mortal(newSViv(UNI_TO_NATIVE(uv)));
497 XSRETURN(1);
498}
499
500XS(XS_Internals_SvREADONLY) /* This is dangerous stuff. */
501{
502 dXSARGS;
503 SV *sv = SvRV(ST(0));
504
505 if (items == 1) {
506 if (SvREADONLY(sv))
507 XSRETURN_YES;
508 else
509 XSRETURN_NO;
510 }
511 else if (items == 2) {
512 if (SvTRUE(ST(1))) {
513 SvREADONLY_on(sv);
514 XSRETURN_YES;
515 }
516 else {
517 /* I hope you really know what you are doing. */
518 SvREADONLY_off(sv);
519 XSRETURN_NO;
520 }
521 }
522 XSRETURN_UNDEF; /* Can't happen. */
523}
524
525XS(XS_Internals_SvREFCNT) /* This is dangerous stuff. */
526{
527 dXSARGS;
528 SV *sv = SvRV(ST(0));
529
530 if (items == 1)
531 XSRETURN_IV(SvREFCNT(sv) - 1); /* Minus the ref created for us. */
532 else if (items == 2) {
533 /* I hope you really know what you are doing. */
534 SvREFCNT(sv) = SvIV(ST(1));
535 XSRETURN_IV(SvREFCNT(sv));
536 }
537 XSRETURN_UNDEF; /* Can't happen. */
538}
539
540XS(XS_Internals_hv_clear_placehold)
541{
542 dXSARGS;
543 HV *hv = (HV *) SvRV(ST(0));
544
545 if (items != 1)
546 Perl_croak(aTHX_ "Usage: UNIVERSAL::hv_clear_placeholders(hv)");
547 hv_clear_placeholders(hv);
548 XSRETURN(0);
549}
550
551XS(XS_Regexp_DESTROY)
552{
553 PERL_UNUSED_ARG(cv);
554}
555
556XS(XS_PerlIO_get_layers)
557{
558 dXSARGS;
559 if (items < 1 || items % 2 == 0)
560 Perl_croak(aTHX_ "Usage: PerlIO_get_layers(filehandle[,args])");
561#ifdef USE_PERLIO
562 {
563 SV * sv;
564 GV * gv;
565 IO * io;
566 bool input = TRUE;
567 bool details = FALSE;
568
569 if (items > 1) {
570 SV **svp;
571
572 for (svp = MARK + 2; svp <= SP; svp += 2) {
573 SV **varp = svp;
574 SV **valp = svp + 1;
575 STRLEN klen;
576 const char *key = SvPV_const(*varp, klen);
577
578 switch (*key) {
579 case 'i':
580 if (klen == 5 && memEQ(key, "input", 5)) {
581 input = SvTRUE(*valp);
582 break;
583 }
584 goto fail;
585 case 'o':
586 if (klen == 6 && memEQ(key, "output", 6)) {
587 input = !SvTRUE(*valp);
588 break;
589 }
590 goto fail;
591 case 'd':
592 if (klen == 7 && memEQ(key, "details", 7)) {
593 details = SvTRUE(*valp);
594 break;
595 }
596 goto fail;
597 default:
598 fail:
599 Perl_croak(aTHX_
600 "get_layers: unknown argument '%s'",
601 key);
602 }
603 }
604
605 SP -= (items - 1);
606 }
607
608 sv = POPs;
609 gv = (GV*)sv;
610
611 if (!isGV(sv)) {
612 if (SvROK(sv) && isGV(SvRV(sv)))
613 gv = (GV*)SvRV(sv);
614 else if (SvPOKp(sv))
615 gv = gv_fetchpv(SvPVX(sv), FALSE, SVt_PVIO);
616 }
617
618 if (gv && (io = GvIO(gv))) {
619 dTARGET;
620 AV* av = PerlIO_get_layers(aTHX_ input ?
621 IoIFP(io) : IoOFP(io));
622 I32 i;
623 I32 last = av_len(av);
624 I32 nitem = 0;
625
626 for (i = last; i >= 0; i -= 3) {
627 SV **namsvp;
628 SV **argsvp;
629 SV **flgsvp;
630 bool namok, argok, flgok;
631
632 namsvp = av_fetch(av, i - 2, FALSE);
633 argsvp = av_fetch(av, i - 1, FALSE);
634 flgsvp = av_fetch(av, i, FALSE);
635
636 namok = namsvp && *namsvp && SvPOK(*namsvp);
637 argok = argsvp && *argsvp && SvPOK(*argsvp);
638 flgok = flgsvp && *flgsvp && SvIOK(*flgsvp);
639
640 if (details) {
641 XPUSHs(namok
642 ? newSVpvn(SvPVX_const(*namsvp), SvCUR(*namsvp))
643 : &PL_sv_undef);
644 XPUSHs(argok
645 ? newSVpvn(SvPVX_const(*argsvp), SvCUR(*argsvp))
646 : &PL_sv_undef);
647 if (flgok)
648 XPUSHi(SvIVX(*flgsvp));
649 else
650 XPUSHs(&PL_sv_undef);
651 nitem += 3;
652 }
653 else {
654 if (namok && argok)
655 XPUSHs(Perl_newSVpvf(aTHX_ "%"SVf"(%"SVf")",
656 *namsvp, *argsvp));
657 else if (namok)
658 XPUSHs(Perl_newSVpvf(aTHX_ "%"SVf, *namsvp));
659 else
660 XPUSHs(&PL_sv_undef);
661 nitem++;
662 if (flgok) {
663 IV flags = SvIVX(*flgsvp);
664
665 if (flags & PERLIO_F_UTF8) {
666 XPUSHs(newSVpvn("utf8", 4));
667 nitem++;
668 }
669 }
670 }
671 }
672
673 SvREFCNT_dec(av);
674
675 XSRETURN(nitem);
676 }
677 }
678#endif
679
680 XSRETURN(0);
681}
682
683XS(XS_Internals_hash_seed)
684{
685 /* Using dXSARGS would also have dITEM and dSP,
686 * which define 2 unused local variables. */
687 dAXMARK;
688 PERL_UNUSED_ARG(cv);
689 PERL_UNUSED_VAR(mark);
690 XSRETURN_UV(PERL_HASH_SEED);
691}
692
693XS(XS_Internals_rehash_seed)
694{
695 /* Using dXSARGS would also have dITEM and dSP,
696 * which define 2 unused local variables. */
697 dAXMARK;
698 PERL_UNUSED_ARG(cv);
699 PERL_UNUSED_VAR(mark);
700 XSRETURN_UV(PL_rehash_seed);
701}
702
703XS(XS_Internals_HvREHASH) /* Subject to change */
704{
705 dXSARGS;
706 if (SvROK(ST(0))) {
707 const HV *hv = (HV *) SvRV(ST(0));
708 if (items == 1 && SvTYPE(hv) == SVt_PVHV) {
709 if (HvREHASH(hv))
710 XSRETURN_YES;
711 else
712 XSRETURN_NO;
713 }
714 }
715 Perl_croak(aTHX_ "Internals::HvREHASH $hashref");
716}
717
718/*
719 * Local variables:
720 * c-indentation-style: bsd
721 * c-basic-offset: 4
722 * indent-tabs-mode: t
723 * End:
724 *
725 * ex: set ts=8 sts=4 sw=4 noet:
726 */
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