3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
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.
12 * 'Mercy!' cried Gandalf. 'If the giving of information is to be the cure
13 * of your inquisitiveness, I shall spend all the rest of my days in answering
14 * you. What more do you want to know?'
15 * 'The names of all the stars, and of all living things, and the whole
16 * history of Middle-earth and Over-heaven and of the Sundering Seas,'
19 * [p.599 of _The Lord of the Rings_, III/xi: "The PalantÃr"]
25 A GV is a structure which corresponds to to a Perl typeglob, ie *foo.
26 It is a structure that holds a pointer to a scalar, an array, a hash etc,
27 corresponding to $foo, @foo, %foo.
29 GVs are usually found as values in stashes (symbol table hashes) where
30 Perl stores its global variables.
41 static const char S_autoload[] = "AUTOLOAD";
42 static const STRLEN S_autolen = sizeof(S_autoload)-1;
45 Perl_gv_add_by_type(pTHX_ GV *gv, svtype type)
52 SvTYPE((const SV *)gv) != SVt_PVGV
53 && SvTYPE((const SV *)gv) != SVt_PVLV
57 if (type == SVt_PVIO) {
59 * if it walks like a dirhandle, then let's assume that
60 * this is a dirhandle.
62 what = OP_IS_DIRHOP(PL_op->op_type) ?
63 "dirhandle" : "filehandle";
64 /* diag_listed_as: Bad symbol for filehandle */
65 } else if (type == SVt_PVHV) {
68 what = type == SVt_PVAV ? "array" : "scalar";
70 Perl_croak(aTHX_ "Bad symbol for %s", what);
73 if (type == SVt_PVHV) {
74 where = (SV **)&GvHV(gv);
75 } else if (type == SVt_PVAV) {
76 where = (SV **)&GvAV(gv);
77 } else if (type == SVt_PVIO) {
78 where = (SV **)&GvIOp(gv);
84 *where = newSV_type(type);
89 Perl_gv_fetchfile(pTHX_ const char *name)
91 PERL_ARGS_ASSERT_GV_FETCHFILE;
92 return gv_fetchfile_flags(name, strlen(name), 0);
96 Perl_gv_fetchfile_flags(pTHX_ const char *const name, const STRLEN namelen,
102 const STRLEN tmplen = namelen + 2;
105 PERL_ARGS_ASSERT_GV_FETCHFILE_FLAGS;
106 PERL_UNUSED_ARG(flags);
111 if (tmplen <= sizeof smallbuf)
114 Newx(tmpbuf, tmplen, char);
115 /* This is where the debugger's %{"::_<$filename"} hash is created */
118 memcpy(tmpbuf + 2, name, namelen);
119 gv = *(GV**)hv_fetch(PL_defstash, tmpbuf, tmplen, TRUE);
121 gv_init(gv, PL_defstash, tmpbuf, tmplen, FALSE);
122 #ifdef PERL_DONT_CREATE_GVSV
123 GvSV(gv) = newSVpvn(name, namelen);
125 sv_setpvn(GvSV(gv), name, namelen);
128 if ((PERLDB_LINE || PERLDB_SAVESRC) && !GvAV(gv))
129 hv_magic(GvHVn(gv_AVadd(gv)), NULL, PERL_MAGIC_dbfile);
130 if (tmpbuf != smallbuf)
136 =for apidoc gv_const_sv
138 If C<gv> is a typeglob whose subroutine entry is a constant sub eligible for
139 inlining, or C<gv> is a placeholder reference that would be promoted to such
140 a typeglob, then returns the value returned by the sub. Otherwise, returns
147 Perl_gv_const_sv(pTHX_ GV *gv)
149 PERL_ARGS_ASSERT_GV_CONST_SV;
151 if (SvTYPE(gv) == SVt_PVGV)
152 return cv_const_sv(GvCVu(gv));
153 return SvROK(gv) ? SvRV(gv) : NULL;
157 Perl_newGP(pTHX_ GV *const gv)
162 const char *const file
163 = (PL_curcop && CopFILE(PL_curcop)) ? CopFILE(PL_curcop) : "";
164 const STRLEN len = strlen(file);
166 SV *const temp_sv = CopFILESV(PL_curcop);
170 PERL_ARGS_ASSERT_NEWGP;
173 file = SvPVX(temp_sv);
174 len = SvCUR(temp_sv);
181 PERL_HASH(hash, file, len);
185 #ifndef PERL_DONT_CREATE_GVSV
186 gp->gp_sv = newSV(0);
189 gp->gp_line = PL_curcop ? CopLINE(PL_curcop) : 0;
190 /* XXX Ideally this cast would be replaced with a change to const char*
192 gp->gp_file_hek = share_hek(file, len, hash);
199 /* Assign CvGV(cv) = gv, handling weak references.
200 * See also S_anonymise_cv_maybe */
203 Perl_cvgv_set(pTHX_ CV* cv, GV* gv)
205 GV * const oldgv = CvGV(cv);
206 PERL_ARGS_ASSERT_CVGV_SET;
217 sv_del_backref(MUTABLE_SV(oldgv), MUTABLE_SV(cv));
221 SvANY(cv)->xcv_gv = gv;
222 assert(!CvCVGV_RC(cv));
227 if (isGV_with_GP(gv) && GvGP(gv) && (GvCV(gv) == cv || GvFORM(gv) == cv))
228 Perl_sv_add_backref(aTHX_ MUTABLE_SV(gv), MUTABLE_SV(cv));
231 SvREFCNT_inc_simple_void_NN(gv);
235 /* Assign CvSTASH(cv) = st, handling weak references. */
238 Perl_cvstash_set(pTHX_ CV *cv, HV *st)
240 HV *oldst = CvSTASH(cv);
241 PERL_ARGS_ASSERT_CVSTASH_SET;
245 sv_del_backref(MUTABLE_SV(oldst), MUTABLE_SV(cv));
246 SvANY(cv)->xcv_stash = st;
248 Perl_sv_add_backref(aTHX_ MUTABLE_SV(st), MUTABLE_SV(cv));
252 Perl_gv_init(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, int multi)
255 const U32 old_type = SvTYPE(gv);
256 const bool doproto = old_type > SVt_NULL;
257 char * const proto = (doproto && SvPOK(gv)) ? SvPVX(gv) : NULL;
258 const STRLEN protolen = proto ? SvCUR(gv) : 0;
259 SV *const has_constant = doproto && SvROK(gv) ? SvRV(gv) : NULL;
260 const U32 exported_constant = has_constant ? SvPCS_IMPORTED(gv) : 0;
262 PERL_ARGS_ASSERT_GV_INIT;
263 assert (!(proto && has_constant));
266 /* The constant has to be a simple scalar type. */
267 switch (SvTYPE(has_constant)) {
273 Perl_croak(aTHX_ "Cannot convert a reference to %s to typeglob",
274 sv_reftype(has_constant, 0));
282 if (old_type < SVt_PVGV) {
283 if (old_type >= SVt_PV)
285 sv_upgrade(MUTABLE_SV(gv), SVt_PVGV);
293 Safefree(SvPVX_mutable(gv));
298 GvGP_set(gv, Perl_newGP(aTHX_ gv));
301 Perl_sv_add_backref(aTHX_ MUTABLE_SV(stash), MUTABLE_SV(gv));
302 gv_name_set(gv, name, len, GV_ADD);
303 if (multi || doproto) /* doproto means it _was_ mentioned */
305 if (doproto) { /* Replicate part of newSUB here. */
311 /* newCONSTSUB doesn't take a len arg, so make sure we
312 * give it a \0-terminated string */
313 name0 = savepvn(name,len);
315 /* newCONSTSUB takes ownership of the reference from us. */
316 cv = newCONSTSUB(stash, (name0 ? name0 : name), has_constant);
317 /* In case op.c:S_process_special_blocks stole it: */
319 GvCV_set(gv, (CV *)SvREFCNT_inc_simple_NN(cv));
320 assert(GvCV(gv) == cv); /* newCONSTSUB should have set this */
323 /* If this reference was a copy of another, then the subroutine
324 must have been "imported", by a Perl space assignment to a GV
325 from a reference to CV. */
326 if (exported_constant)
327 GvIMPORTED_CV_on(gv);
329 (void) start_subparse(0,0); /* Create empty CV in compcv. */
335 mro_method_changed_in(GvSTASH(gv)); /* sub Foo::bar($) { (shift) } sub ASDF::baz($); *ASDF::baz = \&Foo::bar */
337 CvFILE_set_from_cop(cv, PL_curcop);
338 CvSTASH_set(cv, PL_curstash);
340 sv_usepvn_flags(MUTABLE_SV(cv), proto, protolen,
341 SV_HAS_TRAILING_NUL);
347 S_gv_init_sv(pTHX_ GV *gv, const svtype sv_type)
349 PERL_ARGS_ASSERT_GV_INIT_SV;
361 #ifdef PERL_DONT_CREATE_GVSV
369 /* Work round what appears to be a bug in Sun C++ 5.8 2005/10/13
370 If we just cast GvSVn(gv) to void, it ignores evaluating it for
378 =for apidoc gv_fetchmeth
380 Returns the glob with the given C<name> and a defined subroutine or
381 C<NULL>. The glob lives in the given C<stash>, or in the stashes
382 accessible via @ISA and UNIVERSAL::.
384 The argument C<level> should be either 0 or -1. If C<level==0>, as a
385 side-effect creates a glob with the given C<name> in the given C<stash>
386 which in the case of success contains an alias for the subroutine, and sets
387 up caching info for this glob.
389 This function grants C<"SUPER"> token as a postfix of the stash name. The
390 GV returned from C<gv_fetchmeth> may be a method cache entry, which is not
391 visible to Perl code. So when calling C<call_sv>, you should not use
392 the GV directly; instead, you should use the method's CV, which can be
393 obtained from the GV with the C<GvCV> macro.
398 /* NOTE: No support for tied ISA */
401 Perl_gv_fetchmeth(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
409 GV* candidate = NULL;
413 I32 create = (level >= 0) ? 1 : 0;
418 PERL_ARGS_ASSERT_GV_FETCHMETH;
420 /* UNIVERSAL methods should be callable without a stash */
422 create = 0; /* probably appropriate */
423 if(!(stash = gv_stashpvs("UNIVERSAL", 0)))
429 hvname = HvNAME_get(stash);
431 Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup");
436 DEBUG_o( Perl_deb(aTHX_ "Looking for method %s in package %s\n",name,hvname) );
438 topgen_cmp = HvMROMETA(stash)->cache_gen + PL_sub_generation;
440 /* check locally for a real method or a cache entry */
441 gvp = (GV**)hv_fetch(stash, name, len, create);
445 if (SvTYPE(topgv) != SVt_PVGV)
446 gv_init(topgv, stash, name, len, TRUE);
447 if ((cand_cv = GvCV(topgv))) {
448 /* If genuine method or valid cache entry, use it */
449 if (!GvCVGEN(topgv) || GvCVGEN(topgv) == topgen_cmp) {
453 /* stale cache entry, junk it and move on */
454 SvREFCNT_dec(cand_cv);
455 GvCV_set(topgv, NULL);
460 else if (GvCVGEN(topgv) == topgen_cmp) {
461 /* cache indicates no such method definitively */
466 packlen = HvNAMELEN_get(stash);
467 if (packlen >= 7 && strEQ(hvname + packlen - 7, "::SUPER")) {
470 basestash = gv_stashpvn(hvname, packlen, GV_ADD);
471 linear_av = mro_get_linear_isa(basestash);
474 linear_av = mro_get_linear_isa(stash); /* has ourselves at the top of the list */
477 linear_svp = AvARRAY(linear_av) + 1; /* skip over self */
478 items = AvFILLp(linear_av); /* no +1, to skip over self */
480 linear_sv = *linear_svp++;
482 cstash = gv_stashsv(linear_sv, 0);
485 Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA",
486 SVfARG(linear_sv), hvname);
492 gvp = (GV**)hv_fetch(cstash, name, len, 0);
496 if (SvTYPE(candidate) != SVt_PVGV) gv_init(candidate, cstash, name, len, TRUE);
497 if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) {
499 * Found real method, cache method in topgv if:
500 * 1. topgv has no synonyms (else inheritance crosses wires)
501 * 2. method isn't a stub (else AUTOLOAD fails spectacularly)
503 if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
504 CV *old_cv = GvCV(topgv);
505 SvREFCNT_dec(old_cv);
506 SvREFCNT_inc_simple_void_NN(cand_cv);
507 GvCV_set(topgv, cand_cv);
508 GvCVGEN(topgv) = topgen_cmp;
514 /* Check UNIVERSAL without caching */
515 if(level == 0 || level == -1) {
516 candidate = gv_fetchmeth(NULL, name, len, 1);
518 cand_cv = GvCV(candidate);
519 if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
520 CV *old_cv = GvCV(topgv);
521 SvREFCNT_dec(old_cv);
522 SvREFCNT_inc_simple_void_NN(cand_cv);
523 GvCV_set(topgv, cand_cv);
524 GvCVGEN(topgv) = topgen_cmp;
530 if (topgv && GvREFCNT(topgv) == 1) {
531 /* cache the fact that the method is not defined */
532 GvCVGEN(topgv) = topgen_cmp;
539 =for apidoc gv_fetchmeth_autoload
541 Same as gv_fetchmeth(), but looks for autoloaded subroutines too.
542 Returns a glob for the subroutine.
544 For an autoloaded subroutine without a GV, will create a GV even
545 if C<level < 0>. For an autoloaded subroutine without a stub, GvCV()
546 of the result may be zero.
552 Perl_gv_fetchmeth_autoload(pTHX_ HV *stash, const char *name, STRLEN len, I32 level)
554 GV *gv = gv_fetchmeth(stash, name, len, level);
556 PERL_ARGS_ASSERT_GV_FETCHMETH_AUTOLOAD;
563 return NULL; /* UNIVERSAL::AUTOLOAD could cause trouble */
564 if (len == S_autolen && memEQ(name, S_autoload, S_autolen))
566 if (!(gv = gv_fetchmeth(stash, S_autoload, S_autolen, FALSE)))
569 if (!(CvROOT(cv) || CvXSUB(cv)))
571 /* Have an autoload */
572 if (level < 0) /* Cannot do without a stub */
573 gv_fetchmeth(stash, name, len, 0);
574 gvp = (GV**)hv_fetch(stash, name, len, (level >= 0));
583 =for apidoc gv_fetchmethod_autoload
585 Returns the glob which contains the subroutine to call to invoke the method
586 on the C<stash>. In fact in the presence of autoloading this may be the
587 glob for "AUTOLOAD". In this case the corresponding variable $AUTOLOAD is
590 The third parameter of C<gv_fetchmethod_autoload> determines whether
591 AUTOLOAD lookup is performed if the given method is not present: non-zero
592 means yes, look for AUTOLOAD; zero means no, don't look for AUTOLOAD.
593 Calling C<gv_fetchmethod> is equivalent to calling C<gv_fetchmethod_autoload>
594 with a non-zero C<autoload> parameter.
596 These functions grant C<"SUPER"> token as a prefix of the method name. Note
597 that if you want to keep the returned glob for a long time, you need to
598 check for it being "AUTOLOAD", since at the later time the call may load a
599 different subroutine due to $AUTOLOAD changing its value. Use the glob
600 created via a side effect to do this.
602 These functions have the same side-effects and as C<gv_fetchmeth> with
603 C<level==0>. C<name> should be writable if contains C<':'> or C<'
604 ''>. The warning against passing the GV returned by C<gv_fetchmeth> to
605 C<call_sv> apply equally to these functions.
611 S_gv_get_super_pkg(pTHX_ const char* name, I32 namelen)
618 PERL_ARGS_ASSERT_GV_GET_SUPER_PKG;
620 stash = gv_stashpvn(name, namelen, 0);
621 if(stash) return stash;
623 /* If we must create it, give it an @ISA array containing
624 the real package this SUPER is for, so that it's tied
625 into the cache invalidation code correctly */
626 stash = gv_stashpvn(name, namelen, GV_ADD);
627 gvp = (GV**)hv_fetchs(stash, "ISA", TRUE);
629 gv_init(gv, stash, "ISA", 3, TRUE);
630 superisa = GvAVn(gv);
632 sv_magic(MUTABLE_SV(superisa), MUTABLE_SV(gv), PERL_MAGIC_isa, NULL, 0);
634 av_push(superisa, newSVpv(CopSTASHPV(PL_curcop), 0));
636 av_push(superisa, newSVhek(CopSTASH(PL_curcop)
637 ? HvNAME_HEK(CopSTASH(PL_curcop)) : NULL));
644 Perl_gv_fetchmethod_autoload(pTHX_ HV *stash, const char *name, I32 autoload)
646 PERL_ARGS_ASSERT_GV_FETCHMETHOD_AUTOLOAD;
648 return gv_fetchmethod_flags(stash, name, autoload ? GV_AUTOLOAD : 0);
651 /* Don't merge this yet, as it's likely to get a len parameter, and possibly
654 Perl_gv_fetchmethod_flags(pTHX_ HV *stash, const char *name, U32 flags)
657 register const char *nend;
658 const char *nsplit = NULL;
661 const char * const origname = name;
662 SV *const error_report = MUTABLE_SV(stash);
663 const U32 autoload = flags & GV_AUTOLOAD;
664 const U32 do_croak = flags & GV_CROAK;
666 PERL_ARGS_ASSERT_GV_FETCHMETHOD_FLAGS;
668 if (SvTYPE(stash) < SVt_PVHV)
671 /* The only way stash can become NULL later on is if nsplit is set,
672 which in turn means that there is no need for a SVt_PVHV case
673 the error reporting code. */
676 for (nend = name; *nend; nend++) {
681 else if (*nend == ':' && *(nend + 1) == ':') {
687 if ((nsplit - origname) == 5 && memEQ(origname, "SUPER", 5)) {
688 /* ->SUPER::method should really be looked up in original stash */
689 SV * const tmpstr = sv_2mortal(Perl_newSVpvf(aTHX_ "%s::SUPER",
690 CopSTASHPV(PL_curcop)));
691 /* __PACKAGE__::SUPER stash should be autovivified */
692 stash = gv_get_super_pkg(SvPVX_const(tmpstr), SvCUR(tmpstr));
693 DEBUG_o( Perl_deb(aTHX_ "Treating %s as %s::%s\n",
694 origname, HvNAME_get(stash), name) );
697 /* don't autovifify if ->NoSuchStash::method */
698 stash = gv_stashpvn(origname, nsplit - origname, 0);
700 /* however, explicit calls to Pkg::SUPER::method may
701 happen, and may require autovivification to work */
702 if (!stash && (nsplit - origname) >= 7 &&
703 strnEQ(nsplit - 7, "::SUPER", 7) &&
704 gv_stashpvn(origname, nsplit - origname - 7, 0))
705 stash = gv_get_super_pkg(origname, nsplit - origname);
710 gv = gv_fetchmeth(stash, name, nend - name, 0);
712 if (strEQ(name,"import") || strEQ(name,"unimport"))
713 gv = MUTABLE_GV(&PL_sv_yes);
715 gv = gv_autoload4(ostash, name, nend - name, TRUE);
716 if (!gv && do_croak) {
717 /* Right now this is exclusively for the benefit of S_method_common
720 /* If we can't find an IO::File method, it might be a call on
721 * a filehandle. If IO:File has not been loaded, try to
722 * require it first instead of croaking */
723 const char *stash_name = HvNAME_get(stash);
724 if (stash_name && memEQs(stash_name, HvNAMELEN_get(stash), "IO::File")
725 && !Perl_hv_common(aTHX_ GvHVn(PL_incgv), NULL,
726 STR_WITH_LEN("IO/File.pm"), 0,
727 HV_FETCH_ISEXISTS, NULL, 0)
729 require_pv("IO/File.pm");
730 gv = gv_fetchmeth(stash, name, nend - name, 0);
735 "Can't locate object method \"%s\" via package \"%.*s\"",
736 name, (int)HvNAMELEN_get(stash), HvNAME_get(stash));
740 const char *packname;
743 packlen = nsplit - origname;
746 packname = SvPV_const(error_report, packlen);
750 "Can't locate object method \"%s\" via package \"%.*s\""
751 " (perhaps you forgot to load \"%.*s\"?)",
752 name, (int)packlen, packname, (int)packlen, packname);
757 CV* const cv = GvCV(gv);
758 if (!CvROOT(cv) && !CvXSUB(cv)) {
766 if (GvCV(stubgv) != cv) /* orphaned import */
769 autogv = gv_autoload4(GvSTASH(stubgv),
770 GvNAME(stubgv), GvNAMELEN(stubgv), TRUE);
780 Perl_gv_autoload4(pTHX_ HV *stash, const char *name, STRLEN len, I32 method)
788 const char *packname = "";
789 STRLEN packname_len = 0;
791 PERL_ARGS_ASSERT_GV_AUTOLOAD4;
793 if (len == S_autolen && memEQ(name, S_autoload, S_autolen))
796 if (SvTYPE(stash) < SVt_PVHV) {
797 packname = SvPV_const(MUTABLE_SV(stash), packname_len);
801 packname = HvNAME_get(stash);
802 packname_len = HvNAMELEN_get(stash);
805 if (!(gv = gv_fetchmeth(stash, S_autoload, S_autolen, FALSE)))
809 if (!(CvROOT(cv) || CvXSUB(cv)))
813 * Inheriting AUTOLOAD for non-methods works ... for now.
815 if (!method && (GvCVGEN(gv) || GvSTASH(gv) != stash)
817 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEPRECATED),
818 "Use of inherited AUTOLOAD for non-method %s::%.*s() is deprecated",
819 packname, (int)len, name);
822 /* rather than lookup/init $AUTOLOAD here
823 * only to have the XSUB do another lookup for $AUTOLOAD
824 * and split that value on the last '::',
825 * pass along the same data via some unused fields in the CV
827 CvSTASH_set(cv, stash);
828 SvPV_set(cv, (char *)name); /* cast to lose constness warning */
834 * Given &FOO::AUTOLOAD, set $FOO::AUTOLOAD to desired function name.
835 * The subroutine's original name may not be "AUTOLOAD", so we don't
836 * use that, but for lack of anything better we will use the sub's
837 * original package to look up $AUTOLOAD.
839 varstash = GvSTASH(CvGV(cv));
840 vargv = *(GV**)hv_fetch(varstash, S_autoload, S_autolen, TRUE);
844 gv_init(vargv, varstash, S_autoload, S_autolen, FALSE);
845 #ifdef PERL_DONT_CREATE_GVSV
846 GvSV(vargv) = newSV(0);
850 varsv = GvSVn(vargv);
851 sv_setpvn(varsv, packname, packname_len);
852 sv_catpvs(varsv, "::");
853 /* Ensure SvSETMAGIC() is called if necessary. In particular, to clear
854 tainting if $FOO::AUTOLOAD was previously tainted, but is not now. */
855 sv_catpvn_mg(varsv, name, len);
860 /* require_tie_mod() internal routine for requiring a module
861 * that implements the logic of automatic ties like %! and %-
863 * The "gv" parameter should be the glob.
864 * "varpv" holds the name of the var, used for error messages.
865 * "namesv" holds the module name. Its refcount will be decremented.
866 * "methpv" holds the method name to test for to check that things
867 * are working reasonably close to as expected.
868 * "flags": if flag & 1 then save the scalar before loading.
869 * For the protection of $! to work (it is set by this routine)
870 * the sv slot must already be magicalized.
873 S_require_tie_mod(pTHX_ GV *gv, const char *varpv, SV* namesv, const char *methpv,const U32 flags)
876 HV* stash = gv_stashsv(namesv, 0);
878 PERL_ARGS_ASSERT_REQUIRE_TIE_MOD;
880 if (!stash || !(gv_fetchmethod(stash, methpv))) {
881 SV *module = newSVsv(namesv);
882 char varname = *varpv; /* varpv might be clobbered by load_module,
883 so save it. For the moment it's always
889 PUSHSTACKi(PERLSI_MAGIC);
890 Perl_load_module(aTHX_ PERL_LOADMOD_NOIMPORT, module, NULL);
894 stash = gv_stashsv(namesv, 0);
896 Perl_croak(aTHX_ "panic: Can't use %%%c because %"SVf" is not available",
897 varname, SVfARG(namesv));
898 else if (!gv_fetchmethod(stash, methpv))
899 Perl_croak(aTHX_ "panic: Can't use %%%c because %"SVf" does not support method %s",
900 varname, SVfARG(namesv), methpv);
902 SvREFCNT_dec(namesv);
907 =for apidoc gv_stashpv
909 Returns a pointer to the stash for a specified package. Uses C<strlen> to
910 determine the length of C<name>, then calls C<gv_stashpvn()>.
916 Perl_gv_stashpv(pTHX_ const char *name, I32 create)
918 PERL_ARGS_ASSERT_GV_STASHPV;
919 return gv_stashpvn(name, strlen(name), create);
923 =for apidoc gv_stashpvn
925 Returns a pointer to the stash for a specified package. The C<namelen>
926 parameter indicates the length of the C<name>, in bytes. C<flags> is passed
927 to C<gv_fetchpvn_flags()>, so if set to C<GV_ADD> then the package will be
928 created if it does not already exist. If the package does not exist and
929 C<flags> is 0 (or any other setting that does not create packages) then NULL
937 Perl_gv_stashpvn(pTHX_ const char *name, U32 namelen, I32 flags)
943 U32 tmplen = namelen + 2;
945 PERL_ARGS_ASSERT_GV_STASHPVN;
947 if (tmplen <= sizeof smallbuf)
950 Newx(tmpbuf, tmplen, char);
951 Copy(name, tmpbuf, namelen, char);
952 tmpbuf[namelen] = ':';
953 tmpbuf[namelen+1] = ':';
954 tmpgv = gv_fetchpvn_flags(tmpbuf, tmplen, flags, SVt_PVHV);
955 if (tmpbuf != smallbuf)
960 if (!(flags & ~GV_NOADD_MASK) && !stash) return NULL;
962 if (!HvNAME_get(stash)) {
963 hv_name_set(stash, name, namelen, 0);
965 /* FIXME: This is a repeat of logic in gv_fetchpvn_flags */
966 /* If the containing stash has multiple effective
967 names, see that this one gets them, too. */
968 if (HvAUX(GvSTASH(tmpgv))->xhv_name_count)
969 mro_package_moved(stash, NULL, tmpgv, 1);
975 =for apidoc gv_stashsv
977 Returns a pointer to the stash for a specified package. See C<gv_stashpvn>.
983 Perl_gv_stashsv(pTHX_ SV *sv, I32 flags)
986 const char * const ptr = SvPV_const(sv,len);
988 PERL_ARGS_ASSERT_GV_STASHSV;
990 return gv_stashpvn(ptr, len, flags);
995 Perl_gv_fetchpv(pTHX_ const char *nambeg, I32 add, const svtype sv_type) {
996 PERL_ARGS_ASSERT_GV_FETCHPV;
997 return gv_fetchpvn_flags(nambeg, strlen(nambeg), add, sv_type);
1001 Perl_gv_fetchsv(pTHX_ SV *name, I32 flags, const svtype sv_type) {
1003 const char * const nambeg =
1004 SvPV_flags_const(name, len, flags & GV_NO_SVGMAGIC ? 0 : SV_GMAGIC);
1005 PERL_ARGS_ASSERT_GV_FETCHSV;
1006 return gv_fetchpvn_flags(nambeg, len, flags | SvUTF8(name), sv_type);
1010 S_gv_magicalize_isa(pTHX_ GV *gv)
1014 PERL_ARGS_ASSERT_GV_MAGICALIZE_ISA;
1018 sv_magic(MUTABLE_SV(av), MUTABLE_SV(gv), PERL_MAGIC_isa,
1023 S_gv_magicalize_overload(pTHX_ GV *gv)
1027 PERL_ARGS_ASSERT_GV_MAGICALIZE_OVERLOAD;
1031 hv_magic(hv, NULL, PERL_MAGIC_overload);
1034 static void core_xsub(pTHX_ CV* cv);
1037 Perl_gv_fetchpvn_flags(pTHX_ const char *nambeg, STRLEN full_len, I32 flags,
1038 const svtype sv_type)
1041 register const char *name = nambeg;
1042 register GV *gv = NULL;
1045 register const char *name_cursor;
1047 const I32 no_init = flags & (GV_NOADD_NOINIT | GV_NOINIT);
1048 const I32 no_expand = flags & GV_NOEXPAND;
1049 const I32 add = flags & ~GV_NOADD_MASK;
1050 bool addmg = !!(flags & GV_ADDMG);
1051 const char *const name_end = nambeg + full_len;
1052 const char *const name_em1 = name_end - 1;
1055 PERL_ARGS_ASSERT_GV_FETCHPVN_FLAGS;
1057 if (flags & GV_NOTQUAL) {
1058 /* Caller promised that there is no stash, so we can skip the check. */
1063 if (full_len > 2 && *name == '*' && isALPHA(name[1])) {
1064 /* accidental stringify on a GV? */
1068 for (name_cursor = name; name_cursor < name_end; name_cursor++) {
1069 if (name_cursor < name_em1 &&
1070 ((*name_cursor == ':'
1071 && name_cursor[1] == ':')
1072 || *name_cursor == '\''))
1075 stash = PL_defstash;
1076 if (!stash || !SvREFCNT(stash)) /* symbol table under destruction */
1079 len = name_cursor - name;
1080 if (name_cursor > nambeg) { /* Skip for initial :: or ' */
1082 if (*name_cursor == ':') {
1087 Newx(tmpbuf, len+2, char);
1088 Copy(name, tmpbuf, len, char);
1089 tmpbuf[len++] = ':';
1090 tmpbuf[len++] = ':';
1093 gvp = (GV**)hv_fetch(stash, key, len, add);
1094 gv = gvp ? *gvp : NULL;
1095 if (gv && gv != (const GV *)&PL_sv_undef) {
1096 if (SvTYPE(gv) != SVt_PVGV)
1097 gv_init(gv, stash, key, len, (add & GV_ADDMULTI));
1103 if (!gv || gv == (const GV *)&PL_sv_undef)
1106 if (!(stash = GvHV(gv)))
1108 stash = GvHV(gv) = newHV();
1109 if (!HvNAME_get(stash)) {
1110 if (GvSTASH(gv) == PL_defstash && len == 6
1111 && strnEQ(name, "CORE", 4))
1112 hv_name_set(stash, "CORE", 4, 0);
1115 stash, nambeg, name_cursor-nambeg, 0
1117 /* If the containing stash has multiple effective
1118 names, see that this one gets them, too. */
1119 if (HvAUX(GvSTASH(gv))->xhv_name_count)
1120 mro_package_moved(stash, NULL, gv, 1);
1123 else if (!HvNAME_get(stash))
1124 hv_name_set(stash, nambeg, name_cursor - nambeg, 0);
1127 if (*name_cursor == ':')
1129 name = name_cursor+1;
1130 if (name == name_end)
1132 ? gv : MUTABLE_GV(*hv_fetchs(PL_defstash, "main::", TRUE));
1135 len = name_cursor - name;
1137 /* No stash in name, so see how we can default */
1141 if (len && isIDFIRST_lazy(name)) {
1142 bool global = FALSE;
1150 if ((name[0] == 'I' && name[1] == 'N' && name[2] == 'C')
1151 || (name[0] == 'E' && name[1] == 'N' && name[2] == 'V')
1152 || (name[0] == 'S' && name[1] == 'I' && name[2] == 'G'))
1156 if (name[0] == 'A' && name[1] == 'R' && name[2] == 'G'
1161 if (name[0] == 'S' && name[1] == 'T' && name[2] == 'D'
1162 && name[3] == 'I' && name[4] == 'N')
1166 if ((name[0] == 'S' && name[1] == 'T' && name[2] == 'D')
1167 &&((name[3] == 'O' && name[4] == 'U' && name[5] == 'T')
1168 ||(name[3] == 'E' && name[4] == 'R' && name[5] == 'R')))
1172 if (name[0] == 'A' && name[1] == 'R' && name[2] == 'G'
1173 && name[3] == 'V' && name[4] == 'O' && name[5] == 'U'
1180 stash = PL_defstash;
1181 else if (IN_PERL_COMPILETIME) {
1182 stash = PL_curstash;
1183 if (add && (PL_hints & HINT_STRICT_VARS) &&
1184 sv_type != SVt_PVCV &&
1185 sv_type != SVt_PVGV &&
1186 sv_type != SVt_PVFM &&
1187 sv_type != SVt_PVIO &&
1188 !(len == 1 && sv_type == SVt_PV &&
1189 (*name == 'a' || *name == 'b')) )
1191 gvp = (GV**)hv_fetch(stash,name,len,0);
1193 *gvp == (const GV *)&PL_sv_undef ||
1194 SvTYPE(*gvp) != SVt_PVGV)
1198 else if ((sv_type == SVt_PV && !GvIMPORTED_SV(*gvp)) ||
1199 (sv_type == SVt_PVAV && !GvIMPORTED_AV(*gvp)) ||
1200 (sv_type == SVt_PVHV && !GvIMPORTED_HV(*gvp)) )
1202 /* diag_listed_as: Variable "%s" is not imported%s */
1204 aTHX_ packWARN(WARN_MISC),
1205 "Variable \"%c%s\" is not imported",
1206 sv_type == SVt_PVAV ? '@' :
1207 sv_type == SVt_PVHV ? '%' : '$',
1211 aTHX_ packWARN(WARN_MISC),
1212 "\t(Did you mean &%s instead?)\n", name
1219 stash = CopSTASH(PL_curcop);
1222 stash = PL_defstash;
1225 /* By this point we should have a stash and a name */
1229 SV * const err = Perl_mess(aTHX_
1230 "Global symbol \"%s%s\" requires explicit package name",
1231 (sv_type == SVt_PV ? "$"
1232 : sv_type == SVt_PVAV ? "@"
1233 : sv_type == SVt_PVHV ? "%"
1236 if (USE_UTF8_IN_NAMES)
1239 gv = gv_fetchpvs("<none>::", GV_ADDMULTI, SVt_PVHV);
1241 /* symbol table under destruction */
1250 if (!SvREFCNT(stash)) /* symbol table under destruction */
1253 gvp = (GV**)hv_fetch(stash,name,len,add);
1254 if (!gvp || *gvp == (const GV *)&PL_sv_undef) {
1255 if (addmg) gv = (GV *)newSV(0);
1259 if (SvTYPE(gv) == SVt_PVGV) {
1262 gv_init_sv(gv, sv_type);
1263 if (len == 1 && stash == PL_defstash
1264 && (sv_type == SVt_PVHV || sv_type == SVt_PVGV)) {
1266 require_tie_mod(gv, "!", newSVpvs("Errno"), "TIEHASH", 1);
1267 else if (*name == '-' || *name == '+')
1268 require_tie_mod(gv, name, newSVpvs("Tie::Hash::NamedCapture"), "TIEHASH", 0);
1270 else if (len == 3 && sv_type == SVt_PVAV
1271 && strnEQ(name, "ISA", 3)
1272 && (!GvAV(gv) || !SvSMAGICAL(GvAV(gv))))
1273 gv_magicalize_isa(gv);
1276 } else if (no_init) {
1279 } else if (no_expand && SvROK(gv)) {
1284 /* Adding a new symbol.
1285 Unless of course there was already something non-GV here, in which case
1286 we want to behave as if there was always a GV here, containing some sort
1288 Otherwise we run the risk of creating things like GvIO, which can cause
1289 subtle bugs. eg the one that tripped up SQL::Translator */
1291 faking_it = SvOK(gv);
1293 if (add & GV_ADDWARN)
1294 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL), "Had to create %s unexpectedly", nambeg);
1295 gv_init(gv, stash, name, len, add & GV_ADDMULTI);
1297 if (isALPHA(name[0]) && ! (isLEXWARN_on ? ckWARN(WARN_ONCE)
1298 : (PL_dowarn & G_WARN_ON ) ) )
1301 /* set up magic where warranted */
1302 if (stash != PL_defstash) { /* not the main stash */
1303 /* We only have to check for four names here: EXPORT, ISA, OVERLOAD
1304 and VERSION. All the others apply only to the main stash or to
1305 CORE (which is checked right after this). */
1307 const char * const name2 = name + 1;
1310 if (strnEQ(name2, "XPORT", 5))
1314 if (strEQ(name2, "SA"))
1315 gv_magicalize_isa(gv);
1318 if (strEQ(name2, "VERLOAD"))
1319 gv_magicalize_overload(gv);
1322 if (strEQ(name2, "ERSION"))
1328 goto add_magical_gv;
1331 if (len > 1 /* shortest is uc */ && HvNAMELEN_get(stash) == 4) {
1332 /* Avoid null warning: */
1333 const char * const stashname = HvNAME(stash); assert(stashname);
1334 if (strnEQ(stashname, "CORE", 4)) {
1335 const int code = keyword(name, len, 1);
1336 static const char file[] = __FILE__;
1340 bool ampable = TRUE; /* &{}-able */
1342 yy_parser *oldparser;
1343 I32 oldsavestack_ix;
1345 if (code >= 0) goto add_magical_gv; /* not overridable */
1347 /* no support for \&CORE::infix;
1348 no support for funcs that take labels, as their parsing is
1350 case KEY_and: case KEY_cmp: case KEY_CORE: case KEY_dump:
1351 case KEY_eq: case KEY_ge:
1352 case KEY_gt: case KEY_le: case KEY_lt: case KEY_ne:
1353 case KEY_or: case KEY_x: case KEY_xor:
1354 goto add_magical_gv;
1356 case KEY_chomp: case KEY_chop:
1357 case KEY_each: case KEY_eof: case KEY_exec:
1366 case KEY_truncate: case KEY_unlink:
1373 oldcurcop = PL_curcop;
1374 oldparser = PL_parser;
1375 lex_start(NULL, NULL, 0);
1376 oldcompcv = PL_compcv;
1377 PL_compcv = NULL; /* Prevent start_subparse from setting
1379 oldsavestack_ix = start_subparse(FALSE,0);
1383 /* Avoid calling newXS, as it calls us, and things start to
1385 cv = MUTABLE_CV(newSV_type(SVt_PVCV));
1388 mro_method_changed_in(GvSTASH(gv));
1390 CvXSUB(cv) = core_xsub;
1392 CvGV_set(cv, gv); /* This stops new ATTRSUB from setting CvFILE
1394 (void)gv_fetchfile(file);
1395 CvFILE(cv) = (char *)file;
1396 /* XXX This is inefficient, as doing things this order causes
1397 a prototype check in newATTRSUB. But we have to do
1398 it this order as we need an op number before calling
1400 (void)core_prototype((SV *)cv, name, code, &opnum);
1403 (void)hv_store(stash,name,len,(SV *)gv,0);
1407 newATTRSUB(oldsavestack_ix,
1410 newSVpvn_share(nambeg,full_len,0)
1415 ? newSVuv((UV)opnum)
1416 : newSVpvn(name,len),
1420 assert(GvCV(gv) == cv);
1421 if (opnum != OP_VEC && opnum != OP_SUBSTR)
1422 CvLVALUE_off(cv); /* Now *that* was a neat trick. */
1424 PL_parser = oldparser;
1425 PL_curcop = oldcurcop;
1426 PL_compcv = oldcompcv;
1428 opnumsv = opnum ? newSVuv((UV)opnum) : (SV *)NULL;
1429 cv_set_call_checker(
1430 cv, Perl_ck_entersub_args_core, opnumsv ? opnumsv : (SV *)cv
1432 SvREFCNT_dec(opnumsv);
1440 /* Nothing else to do.
1441 The compiler will probably turn the switch statement into a
1442 branch table. Make sure we avoid even that small overhead for
1443 the common case of lower case variable names. */
1447 const char * const name2 = name + 1;
1450 if (strEQ(name2, "RGV")) {
1451 IoFLAGS(GvIOn(gv)) |= IOf_ARGV|IOf_START;
1453 else if (strEQ(name2, "RGVOUT")) {
1458 if (strnEQ(name2, "XPORT", 5))
1462 if (strEQ(name2, "SA")) {
1463 gv_magicalize_isa(gv);
1467 if (strEQ(name2, "VERLOAD")) {
1468 gv_magicalize_overload(gv);
1472 if (strEQ(name2, "IG")) {
1475 if (!PL_psig_name) {
1476 Newxz(PL_psig_name, 2 * SIG_SIZE, SV*);
1477 Newxz(PL_psig_pend, SIG_SIZE, int);
1478 PL_psig_ptr = PL_psig_name + SIG_SIZE;
1480 /* I think that the only way to get here is to re-use an
1481 embedded perl interpreter, where the previous
1482 use didn't clean up fully because
1483 PL_perl_destruct_level was 0. I'm not sure that we
1484 "support" that, in that I suspect in that scenario
1485 there are sufficient other garbage values left in the
1486 interpreter structure that something else will crash
1487 before we get here. I suspect that this is one of
1488 those "doctor, it hurts when I do this" bugs. */
1489 Zero(PL_psig_name, 2 * SIG_SIZE, SV*);
1490 Zero(PL_psig_pend, SIG_SIZE, int);
1494 hv_magic(hv, NULL, PERL_MAGIC_sig);
1495 for (i = 1; i < SIG_SIZE; i++) {
1496 SV * const * const init = hv_fetch(hv, PL_sig_name[i], strlen(PL_sig_name[i]), 1);
1498 sv_setsv(*init, &PL_sv_undef);
1503 if (strEQ(name2, "ERSION"))
1506 case '\003': /* $^CHILD_ERROR_NATIVE */
1507 if (strEQ(name2, "HILD_ERROR_NATIVE"))
1510 case '\005': /* $^ENCODING */
1511 if (strEQ(name2, "NCODING"))
1514 case '\007': /* $^GLOBAL_PHASE */
1515 if (strEQ(name2, "LOBAL_PHASE"))
1518 case '\015': /* $^MATCH */
1519 if (strEQ(name2, "ATCH"))
1521 case '\017': /* $^OPEN */
1522 if (strEQ(name2, "PEN"))
1525 case '\020': /* $^PREMATCH $^POSTMATCH */
1526 if (strEQ(name2, "REMATCH") || strEQ(name2, "OSTMATCH"))
1529 case '\024': /* ${^TAINT} */
1530 if (strEQ(name2, "AINT"))
1533 case '\025': /* ${^UNICODE}, ${^UTF8LOCALE} */
1534 if (strEQ(name2, "NICODE"))
1536 if (strEQ(name2, "TF8LOCALE"))
1538 if (strEQ(name2, "TF8CACHE"))
1541 case '\027': /* $^WARNING_BITS */
1542 if (strEQ(name2, "ARNING_BITS"))
1555 /* Ensures that we have an all-digit variable, ${"1foo"} fails
1557 /* This snippet is taken from is_gv_magical */
1558 const char *end = name + len;
1559 while (--end > name) {
1560 if (!isDIGIT(*end)) goto add_magical_gv;
1567 /* Names of length 1. (Or 0. But name is NUL terminated, so that will
1568 be case '\0' in this switch statement (ie a default case) */
1574 sv_type == SVt_PVAV ||
1575 sv_type == SVt_PVHV ||
1576 sv_type == SVt_PVCV ||
1577 sv_type == SVt_PVFM ||
1580 PL_sawampersand = TRUE;
1584 sv_setpv(GvSVn(gv),PL_chopset);
1588 #ifdef COMPLEX_STATUS
1589 SvUPGRADE(GvSVn(gv), SVt_PVLV);
1595 /* If %! has been used, automatically load Errno.pm. */
1597 sv_magic(GvSVn(gv), MUTABLE_SV(gv), PERL_MAGIC_sv, name, len);
1599 /* magicalization must be done before require_tie_mod is called */
1600 if (sv_type == SVt_PVHV || sv_type == SVt_PVGV)
1601 require_tie_mod(gv, "!", newSVpvs("Errno"), "TIEHASH", 1);
1606 GvMULTI_on(gv); /* no used once warnings here */
1608 AV* const av = GvAVn(gv);
1609 SV* const avc = (*name == '+') ? MUTABLE_SV(av) : NULL;
1611 sv_magic(MUTABLE_SV(av), avc, PERL_MAGIC_regdata, NULL, 0);
1612 sv_magic(GvSVn(gv), MUTABLE_SV(gv), PERL_MAGIC_sv, name, len);
1614 SvREADONLY_on(GvSVn(gv));
1617 if (sv_type == SVt_PVHV || sv_type == SVt_PVGV)
1618 require_tie_mod(gv, name, newSVpvs("Tie::Hash::NamedCapture"), "TIEHASH", 0);
1624 if (sv_type == SVt_PV)
1625 Perl_ck_warner_d(aTHX_ packWARN2(WARN_DEPRECATED, WARN_SYNTAX),
1626 "$%c is no longer supported", *name);
1629 sv_setiv(GvSVn(gv), (IV)(IoFLAGS(GvIOp(PL_defoutgv)) & IOf_FLUSH) != 0);
1632 case '\010': /* $^H */
1634 HV *const hv = GvHVn(gv);
1635 hv_magic(hv, NULL, PERL_MAGIC_hints);
1638 case '\023': /* $^S */
1640 SvREADONLY_on(GvSVn(gv));
1665 case '\001': /* $^A */
1666 case '\003': /* $^C */
1667 case '\004': /* $^D */
1668 case '\005': /* $^E */
1669 case '\006': /* $^F */
1670 case '\011': /* $^I, NOT \t in EBCDIC */
1671 case '\016': /* $^N */
1672 case '\017': /* $^O */
1673 case '\020': /* $^P */
1674 case '\024': /* $^T */
1675 case '\027': /* $^W */
1677 sv_magic(GvSVn(gv), MUTABLE_SV(gv), PERL_MAGIC_sv, name, len);
1680 case '\014': /* $^L */
1681 sv_setpvs(GvSVn(gv),"\f");
1682 PL_formfeed = GvSVn(gv);
1685 sv_setpvs(GvSVn(gv),"\034");
1689 SV * const sv = GvSV(gv);
1690 if (!sv_derived_from(PL_patchlevel, "version"))
1691 upg_version(PL_patchlevel, TRUE);
1692 GvSV(gv) = vnumify(PL_patchlevel);
1693 SvREADONLY_on(GvSV(gv));
1697 case '\026': /* $^V */
1699 SV * const sv = GvSV(gv);
1700 GvSV(gv) = new_version(PL_patchlevel);
1701 SvREADONLY_on(GvSV(gv));
1709 if (GvAV(gv) || GvHV(gv) || GvIO(gv) || GvCV(gv) || (
1710 GvSV(gv) && (SvOK(GvSV(gv)) || SvMAGICAL(GvSV(gv)))
1712 (void)hv_store(stash,name,len,(SV *)gv,0);
1713 else SvREFCNT_dec(gv), gv = NULL;
1715 if (gv) gv_init_sv(gv, faking_it ? SVt_PVCV : sv_type);
1720 Perl_gv_fullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain)
1724 const HV * const hv = GvSTASH(gv);
1726 PERL_ARGS_ASSERT_GV_FULLNAME4;
1732 sv_setpv(sv, prefix ? prefix : "");
1734 name = HvNAME_get(hv);
1736 namelen = HvNAMELEN_get(hv);
1742 if (keepmain || strNE(name, "main")) {
1743 sv_catpvn(sv,name,namelen);
1746 sv_catpvn(sv,GvNAME(gv),GvNAMELEN(gv));
1750 Perl_gv_efullname4(pTHX_ SV *sv, const GV *gv, const char *prefix, bool keepmain)
1752 const GV * const egv = GvEGVx(gv);
1754 PERL_ARGS_ASSERT_GV_EFULLNAME4;
1756 gv_fullname4(sv, egv ? egv : gv, prefix, keepmain);
1760 Perl_gv_check(pTHX_ const HV *stash)
1765 PERL_ARGS_ASSERT_GV_CHECK;
1767 if (!HvARRAY(stash))
1769 for (i = 0; i <= (I32) HvMAX(stash); i++) {
1771 for (entry = HvARRAY(stash)[i]; entry; entry = HeNEXT(entry)) {
1774 if (HeKEY(entry)[HeKLEN(entry)-1] == ':' &&
1775 (gv = MUTABLE_GV(HeVAL(entry))) && isGV(gv) && (hv = GvHV(gv)))
1777 if (hv != PL_defstash && hv != stash)
1778 gv_check(hv); /* nested package */
1780 else if (isALPHA(*HeKEY(entry))) {
1782 gv = MUTABLE_GV(HeVAL(entry));
1783 if (SvTYPE(gv) != SVt_PVGV || GvMULTI(gv))
1786 CopLINE_set(PL_curcop, GvLINE(gv));
1788 CopFILE(PL_curcop) = (char *)file; /* set for warning */
1790 CopFILEGV(PL_curcop)
1791 = gv_fetchfile_flags(file, HEK_LEN(GvFILE_HEK(gv)), 0);
1793 Perl_warner(aTHX_ packWARN(WARN_ONCE),
1794 "Name \"%s::%s\" used only once: possible typo",
1795 HvNAME_get(stash), GvNAME(gv));
1802 Perl_newGVgen(pTHX_ const char *pack)
1806 PERL_ARGS_ASSERT_NEWGVGEN;
1808 return gv_fetchpv(Perl_form(aTHX_ "%s::_GEN_%ld", pack, (long)PL_gensym++),
1812 /* hopefully this is only called on local symbol table entries */
1815 Perl_gp_ref(pTHX_ GP *gp)
1823 /* If the GP they asked for a reference to contains
1824 a method cache entry, clear it first, so that we
1825 don't infect them with our cached entry */
1826 SvREFCNT_dec(gp->gp_cv);
1835 Perl_gp_free(pTHX_ GV *gv)
1841 if (!gv || !isGV_with_GP(gv) || !(gp = GvGP(gv)))
1843 if (gp->gp_refcnt == 0) {
1844 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
1845 "Attempt to free unreferenced glob pointers"
1846 pTHX__FORMAT pTHX__VALUE);
1849 if (--gp->gp_refcnt > 0) {
1850 if (gp->gp_egv == gv)
1857 /* Copy and null out all the glob slots, so destructors do not see
1859 HEK * const file_hek = gp->gp_file_hek;
1860 SV * const sv = gp->gp_sv;
1861 AV * const av = gp->gp_av;
1862 HV * const hv = gp->gp_hv;
1863 IO * const io = gp->gp_io;
1864 CV * const cv = gp->gp_cv;
1865 CV * const form = gp->gp_form;
1867 gp->gp_file_hek = NULL;
1876 unshare_hek(file_hek);
1880 /* FIXME - another reference loop GV -> symtab -> GV ?
1881 Somehow gp->gp_hv can end up pointing at freed garbage. */
1882 if (hv && SvTYPE(hv) == SVt_PVHV) {
1883 const char *hvname = HvNAME_get(hv);
1884 if (PL_stashcache && hvname)
1885 (void)hv_delete(PL_stashcache, hvname, HvNAMELEN_get(hv),
1893 if (!gp->gp_file_hek
1899 && !gp->gp_form) break;
1901 if (--attempts == 0) {
1903 "panic: gp_free failed to free glob pointer - "
1904 "something is repeatedly re-creating entries"
1914 Perl_magic_freeovrld(pTHX_ SV *sv, MAGIC *mg)
1916 AMT * const amtp = (AMT*)mg->mg_ptr;
1917 PERL_UNUSED_ARG(sv);
1919 PERL_ARGS_ASSERT_MAGIC_FREEOVRLD;
1921 if (amtp && AMT_AMAGIC(amtp)) {
1923 for (i = 1; i < NofAMmeth; i++) {
1924 CV * const cv = amtp->table[i];
1926 SvREFCNT_dec(MUTABLE_SV(cv));
1927 amtp->table[i] = NULL;
1934 /* Updates and caches the CV's */
1936 * 1 on success and there is some overload
1937 * 0 if there is no overload
1938 * -1 if some error occurred and it couldn't croak
1942 Perl_Gv_AMupdate(pTHX_ HV *stash, bool destructing)
1945 MAGIC* const mg = mg_find((const SV *)stash, PERL_MAGIC_overload_table);
1947 const struct mro_meta* stash_meta = HvMROMETA(stash);
1950 PERL_ARGS_ASSERT_GV_AMUPDATE;
1952 newgen = PL_sub_generation + stash_meta->pkg_gen + stash_meta->cache_gen;
1954 const AMT * const amtp = (AMT*)mg->mg_ptr;
1955 if (amtp->was_ok_am == PL_amagic_generation
1956 && amtp->was_ok_sub == newgen) {
1957 return AMT_OVERLOADED(amtp) ? 1 : 0;
1959 sv_unmagic(MUTABLE_SV(stash), PERL_MAGIC_overload_table);
1962 DEBUG_o( Perl_deb(aTHX_ "Recalcing overload magic in package %s\n",HvNAME_get(stash)) );
1965 amt.was_ok_am = PL_amagic_generation;
1966 amt.was_ok_sub = newgen;
1967 amt.fallback = AMGfallNO;
1971 int filled = 0, have_ovl = 0;
1974 /* Work with "fallback" key, which we assume to be first in PL_AMG_names */
1976 /* Try to find via inheritance. */
1977 GV *gv = gv_fetchmeth(stash, PL_AMG_names[0], 2, -1);
1978 SV * const sv = gv ? GvSV(gv) : NULL;
1982 lim = DESTROY_amg; /* Skip overloading entries. */
1983 #ifdef PERL_DONT_CREATE_GVSV
1985 NOOP; /* Equivalent to !SvTRUE and !SvOK */
1988 else if (SvTRUE(sv))
1989 amt.fallback=AMGfallYES;
1991 amt.fallback=AMGfallNEVER;
1993 for (i = 1; i < lim; i++)
1994 amt.table[i] = NULL;
1995 for (; i < NofAMmeth; i++) {
1996 const char * const cooky = PL_AMG_names[i];
1997 /* Human-readable form, for debugging: */
1998 const char * const cp = (i >= DESTROY_amg ? cooky : AMG_id2name(i));
1999 const STRLEN l = PL_AMG_namelens[i];
2001 DEBUG_o( Perl_deb(aTHX_ "Checking overloading of \"%s\" in package \"%.256s\"\n",
2002 cp, HvNAME_get(stash)) );
2003 /* don't fill the cache while looking up!
2004 Creation of inheritance stubs in intermediate packages may
2005 conflict with the logic of runtime method substitution.
2006 Indeed, for inheritance A -> B -> C, if C overloads "+0",
2007 then we could have created stubs for "(+0" in A and C too.
2008 But if B overloads "bool", we may want to use it for
2009 numifying instead of C's "+0". */
2010 if (i >= DESTROY_amg)
2011 gv = Perl_gv_fetchmeth_autoload(aTHX_ stash, cooky, l, 0);
2012 else /* Autoload taken care of below */
2013 gv = Perl_gv_fetchmeth(aTHX_ stash, cooky, l, -1);
2015 if (gv && (cv = GvCV(gv))) {
2017 if (GvNAMELEN(CvGV(cv)) == 3 && strEQ(GvNAME(CvGV(cv)), "nil")
2018 && strEQ(hvname = HvNAME_get(GvSTASH(CvGV(cv))), "overload")) {
2019 /* This is a hack to support autoloading..., while
2020 knowing *which* methods were declared as overloaded. */
2021 /* GvSV contains the name of the method. */
2023 SV *gvsv = GvSV(gv);
2025 DEBUG_o( Perl_deb(aTHX_ "Resolving method \"%"SVf256\
2026 "\" for overloaded \"%s\" in package \"%.256s\"\n",
2027 (void*)GvSV(gv), cp, hvname) );
2028 if (!gvsv || !SvPOK(gvsv)
2029 || !(ngv = gv_fetchmethod_autoload(stash, SvPVX_const(gvsv),
2032 /* Can be an import stub (created by "can"). */
2037 const char * const name = (gvsv && SvPOK(gvsv)) ? SvPVX_const(gvsv) : "???";
2038 Perl_croak(aTHX_ "%s method \"%.256s\" overloading \"%s\" "\
2039 "in package \"%.256s\"",
2040 (GvCVGEN(gv) ? "Stub found while resolving"
2045 cv = GvCV(gv = ngv);
2047 DEBUG_o( Perl_deb(aTHX_ "Overloading \"%s\" in package \"%.256s\" via \"%.256s::%.256s\"\n",
2048 cp, HvNAME_get(stash), HvNAME_get(GvSTASH(CvGV(cv))),
2049 GvNAME(CvGV(cv))) );
2051 if (i < DESTROY_amg)
2053 } else if (gv) { /* Autoloaded... */
2054 cv = MUTABLE_CV(gv);
2057 amt.table[i]=MUTABLE_CV(SvREFCNT_inc_simple(cv));
2060 AMT_AMAGIC_on(&amt);
2062 AMT_OVERLOADED_on(&amt);
2063 sv_magic(MUTABLE_SV(stash), 0, PERL_MAGIC_overload_table,
2064 (char*)&amt, sizeof(AMT));
2068 /* Here we have no table: */
2070 AMT_AMAGIC_off(&amt);
2071 sv_magic(MUTABLE_SV(stash), 0, PERL_MAGIC_overload_table,
2072 (char*)&amt, sizeof(AMTS));
2078 Perl_gv_handler(pTHX_ HV *stash, I32 id)
2084 struct mro_meta* stash_meta;
2086 if (!stash || !HvNAME_get(stash))
2089 stash_meta = HvMROMETA(stash);
2090 newgen = PL_sub_generation + stash_meta->pkg_gen + stash_meta->cache_gen;
2092 mg = mg_find((const SV *)stash, PERL_MAGIC_overload_table);
2095 /* If we're looking up a destructor to invoke, we must avoid
2096 * that Gv_AMupdate croaks, because we might be dying already */
2097 if (Gv_AMupdate(stash, cBOOL(id == DESTROY_amg)) == -1) {
2098 /* and if it didn't found a destructor, we fall back
2099 * to a simpler method that will only look for the
2100 * destructor instead of the whole magic */
2101 if (id == DESTROY_amg) {
2102 GV * const gv = gv_fetchmethod(stash, "DESTROY");
2108 mg = mg_find((const SV *)stash, PERL_MAGIC_overload_table);
2111 amtp = (AMT*)mg->mg_ptr;
2112 if ( amtp->was_ok_am != PL_amagic_generation
2113 || amtp->was_ok_sub != newgen )
2115 if (AMT_AMAGIC(amtp)) {
2116 CV * const ret = amtp->table[id];
2117 if (ret && isGV(ret)) { /* Autoloading stab */
2118 /* Passing it through may have resulted in a warning
2119 "Inherited AUTOLOAD for a non-method deprecated", since
2120 our caller is going through a function call, not a method call.
2121 So return the CV for AUTOLOAD, setting $AUTOLOAD. */
2122 GV * const gv = gv_fetchmethod(stash, PL_AMG_names[id]);
2134 /* Implement tryAMAGICun_MG macro.
2135 Do get magic, then see if the stack arg is overloaded and if so call it.
2137 AMGf_set return the arg using SETs rather than assigning to
2139 AMGf_numeric apply sv_2num to the stack arg.
2143 Perl_try_amagic_un(pTHX_ int method, int flags) {
2147 SV* const arg = TOPs;
2151 if (SvAMAGIC(arg) && (tmpsv = amagic_call(arg, &PL_sv_undef, method,
2152 AMGf_noright | AMGf_unary))) {
2153 if (flags & AMGf_set) {
2158 if (SvPADMY(TARG)) {
2159 sv_setsv(TARG, tmpsv);
2169 if ((flags & AMGf_numeric) && SvROK(arg))
2175 /* Implement tryAMAGICbin_MG macro.
2176 Do get magic, then see if the two stack args are overloaded and if so
2179 AMGf_set return the arg using SETs rather than assigning to
2181 AMGf_assign op may be called as mutator (eg +=)
2182 AMGf_numeric apply sv_2num to the stack arg.
2186 Perl_try_amagic_bin(pTHX_ int method, int flags) {
2189 SV* const left = TOPm1s;
2190 SV* const right = TOPs;
2196 if (SvAMAGIC(left) || SvAMAGIC(right)) {
2197 SV * const tmpsv = amagic_call(left, right, method,
2198 ((flags & AMGf_assign) && opASSIGN ? AMGf_assign: 0));
2200 if (flags & AMGf_set) {
2207 if (opASSIGN || SvPADMY(TARG)) {
2208 sv_setsv(TARG, tmpsv);
2218 if(left==right && SvGMAGICAL(left)) {
2219 SV * const left = sv_newmortal();
2221 /* Print the uninitialized warning now, so it includes the vari-
2224 if (ckWARN(WARN_UNINITIALIZED)) report_uninit(right);
2225 sv_setsv_flags(left, &PL_sv_no, 0);
2227 else sv_setsv_flags(left, right, 0);
2230 if (flags & AMGf_numeric) {
2232 *(sp-1) = sv_2num(TOPm1s);
2234 *sp = sv_2num(right);
2240 Perl_amagic_deref_call(pTHX_ SV *ref, int method) {
2243 PERL_ARGS_ASSERT_AMAGIC_DEREF_CALL;
2245 while (SvAMAGIC(ref) &&
2246 (tmpsv = amagic_call(ref, &PL_sv_undef, method,
2247 AMGf_noright | AMGf_unary))) {
2249 Perl_croak(aTHX_ "Overloaded dereference did not return a reference");
2250 if (tmpsv == ref || SvRV(tmpsv) == SvRV(ref)) {
2251 /* Bail out if it returns us the same reference. */
2256 return tmpsv ? tmpsv : ref;
2260 Perl_amagic_call(pTHX_ SV *left, SV *right, int method, int flags)
2265 CV **cvp=NULL, **ocvp=NULL;
2266 AMT *amtp=NULL, *oamtp=NULL;
2267 int off = 0, off1, lr = 0, notfound = 0;
2268 int postpr = 0, force_cpy = 0;
2269 int assign = AMGf_assign & flags;
2270 const int assignshift = assign ? 1 : 0;
2271 int use_default_op = 0;
2277 PERL_ARGS_ASSERT_AMAGIC_CALL;
2279 if ( PL_curcop->cop_hints & HINT_NO_AMAGIC ) {
2280 SV *lex_mask = cop_hints_fetch_pvs(PL_curcop, "overloading", 0);
2282 if ( !lex_mask || !SvOK(lex_mask) )
2283 /* overloading lexically disabled */
2285 else if ( lex_mask && SvPOK(lex_mask) ) {
2286 /* we have an entry in the hints hash, check if method has been
2287 * masked by overloading.pm */
2289 const int offset = method / 8;
2290 const int bit = method % 8;
2291 char *pv = SvPV(lex_mask, len);
2293 /* Bit set, so this overloading operator is disabled */
2294 if ( (STRLEN)offset < len && pv[offset] & ( 1 << bit ) )
2299 if (!(AMGf_noleft & flags) && SvAMAGIC(left)
2300 && (stash = SvSTASH(SvRV(left)))
2301 && (mg = mg_find((const SV *)stash, PERL_MAGIC_overload_table))
2302 && (ocvp = cvp = (AMT_AMAGIC((AMT*)mg->mg_ptr)
2303 ? (oamtp = amtp = (AMT*)mg->mg_ptr)->table
2305 && ((cv = cvp[off=method+assignshift])
2306 || (assign && amtp->fallback > AMGfallNEVER && /* fallback to
2312 cv = cvp[off=method])))) {
2313 lr = -1; /* Call method for left argument */
2315 if (cvp && amtp->fallback > AMGfallNEVER && flags & AMGf_unary) {
2318 /* look for substituted methods */
2319 /* In all the covered cases we should be called with assign==0. */
2323 if ((cv = cvp[off=add_ass_amg])
2324 || ((cv = cvp[off = add_amg]) && (force_cpy = 0, postpr = 1))) {
2325 right = &PL_sv_yes; lr = -1; assign = 1;
2330 if ((cv = cvp[off = subtr_ass_amg])
2331 || ((cv = cvp[off = subtr_amg]) && (force_cpy = 0, postpr=1))) {
2332 right = &PL_sv_yes; lr = -1; assign = 1;
2336 (void)((cv = cvp[off=numer_amg]) || (cv = cvp[off=string_amg]));
2339 (void)((cv = cvp[off=string_amg]) || (cv = cvp[off=bool__amg]));
2342 (void)((cv = cvp[off=numer_amg]) || (cv = cvp[off=bool__amg]));
2345 (void)((cv = cvp[off=bool__amg])
2346 || (cv = cvp[off=numer_amg])
2347 || (cv = cvp[off=string_amg]));
2354 * SV* ref causes confusion with the interpreter variable of
2357 SV* const tmpRef=SvRV(left);
2358 if (!SvROK(tmpRef) && SvTYPE(tmpRef) <= SVt_PVMG) {
2360 * Just to be extra cautious. Maybe in some
2361 * additional cases sv_setsv is safe, too.
2363 SV* const newref = newSVsv(tmpRef);
2364 SvOBJECT_on(newref);
2365 /* As a bit of a source compatibility hack, SvAMAGIC() and
2366 friends dereference an RV, to behave the same was as when
2367 overloading was stored on the reference, not the referant.
2368 Hence we can't use SvAMAGIC_on()
2370 SvFLAGS(newref) |= SVf_AMAGIC;
2371 SvSTASH_set(newref, MUTABLE_HV(SvREFCNT_inc(SvSTASH(tmpRef))));
2377 if ((cvp[off1=lt_amg] || cvp[off1=ncmp_amg])
2378 && ((cv = cvp[off=neg_amg]) || (cv = cvp[off=subtr_amg]))) {
2379 SV* const nullsv=sv_2mortal(newSViv(0));
2381 SV* const lessp = amagic_call(left,nullsv,
2382 lt_amg,AMGf_noright);
2383 logic = SvTRUE(lessp);
2385 SV* const lessp = amagic_call(left,nullsv,
2386 ncmp_amg,AMGf_noright);
2387 logic = (SvNV(lessp) < 0);
2390 if (off==subtr_amg) {
2401 if ((cv = cvp[off=subtr_amg])) {
2403 left = sv_2mortal(newSViv(0));
2408 case iter_amg: /* XXXX Eventually should do to_gv. */
2409 case ftest_amg: /* XXXX Eventually should do to_gv. */
2412 return NULL; /* Delegate operation to standard mechanisms. */
2420 return left; /* Delegate operation to standard mechanisms. */
2425 if (!cv) goto not_found;
2426 } else if (!(AMGf_noright & flags) && SvAMAGIC(right)
2427 && (stash = SvSTASH(SvRV(right)))
2428 && (mg = mg_find((const SV *)stash, PERL_MAGIC_overload_table))
2429 && (cvp = (AMT_AMAGIC((AMT*)mg->mg_ptr)
2430 ? (amtp = (AMT*)mg->mg_ptr)->table
2432 && (cv = cvp[off=method])) { /* Method for right
2435 } else if (((cvp && amtp->fallback > AMGfallNEVER)
2436 || (ocvp && oamtp->fallback > AMGfallNEVER))
2437 && !(flags & AMGf_unary)) {
2438 /* We look for substitution for
2439 * comparison operations and
2441 if (method==concat_amg || method==concat_ass_amg
2442 || method==repeat_amg || method==repeat_ass_amg) {
2443 return NULL; /* Delegate operation to string conversion */
2465 if (ocvp && (oamtp->fallback > AMGfallNEVER)) {
2469 if (!cv && (cvp && amtp->fallback > AMGfallNEVER)) {
2479 not_found: /* No method found, either report or croak */
2487 return left; /* Delegate operation to standard mechanisms. */
2490 if (ocvp && (cv=ocvp[nomethod_amg])) { /* Call report method */
2491 notfound = 1; lr = -1;
2492 } else if (cvp && (cv=cvp[nomethod_amg])) {
2493 notfound = 1; lr = 1;
2494 } else if ((use_default_op =
2495 (!ocvp || oamtp->fallback >= AMGfallYES)
2496 && (!cvp || amtp->fallback >= AMGfallYES))
2498 /* Skip generating the "no method found" message. */
2502 if (off==-1) off=method;
2503 msg = sv_2mortal(Perl_newSVpvf(aTHX_
2504 "Operation \"%s\": no method found,%sargument %s%s%s%s",
2505 AMG_id2name(method + assignshift),
2506 (flags & AMGf_unary ? " " : "\n\tleft "),
2508 "in overloaded package ":
2509 "has no overloaded magic",
2511 HvNAME_get(SvSTASH(SvRV(left))):
2514 ",\n\tright argument in overloaded package ":
2517 : ",\n\tright argument has no overloaded magic"),
2519 HvNAME_get(SvSTASH(SvRV(right))):
2521 if (use_default_op) {
2522 DEBUG_o( Perl_deb(aTHX_ "%s", SvPVX_const(msg)) );
2524 Perl_croak(aTHX_ "%"SVf, SVfARG(msg));
2528 force_cpy = force_cpy || assign;
2533 DEBUG_o(Perl_deb(aTHX_
2534 "Overloaded operator \"%s\"%s%s%s:\n\tmethod%s found%s in package %s%s\n",
2536 method+assignshift==off? "" :
2538 method+assignshift==off? "" :
2539 AMG_id2name(method+assignshift),
2540 method+assignshift==off? "" : "\")",
2541 flags & AMGf_unary? "" :
2542 lr==1 ? " for right argument": " for left argument",
2543 flags & AMGf_unary? " for argument" : "",
2544 stash ? HvNAME_get(stash) : "null",
2545 fl? ",\n\tassignment variant used": "") );
2548 /* Since we use shallow copy during assignment, we need
2549 * to dublicate the contents, probably calling user-supplied
2550 * version of copy operator
2552 /* We need to copy in following cases:
2553 * a) Assignment form was called.
2554 * assignshift==1, assign==T, method + 1 == off
2555 * b) Increment or decrement, called directly.
2556 * assignshift==0, assign==0, method + 0 == off
2557 * c) Increment or decrement, translated to assignment add/subtr.
2558 * assignshift==0, assign==T,
2560 * d) Increment or decrement, translated to nomethod.
2561 * assignshift==0, assign==0,
2563 * e) Assignment form translated to nomethod.
2564 * assignshift==1, assign==T, method + 1 != off
2567 /* off is method, method+assignshift, or a result of opcode substitution.
2568 * In the latter case assignshift==0, so only notfound case is important.
2570 if (( (method + assignshift == off)
2571 && (assign || (method == inc_amg) || (method == dec_amg)))
2574 /* newSVsv does not behave as advertised, so we copy missing
2575 * information by hand */
2576 SV *tmpRef = SvRV(left);
2578 if (SvREFCNT(tmpRef) > 1 && (rv_copy = AMG_CALLunary(left,copy_amg))) {
2579 SvRV_set(left, rv_copy);
2581 SvREFCNT_dec(tmpRef);
2589 const bool oldcatch = CATCH_GET;
2592 Zero(&myop, 1, BINOP);
2593 myop.op_last = (OP *) &myop;
2594 myop.op_next = NULL;
2595 myop.op_flags = OPf_WANT_SCALAR | OPf_STACKED;
2597 PUSHSTACKi(PERLSI_OVERLOAD);
2600 PL_op = (OP *) &myop;
2601 if (PERLDB_SUB && PL_curstash != PL_debstash)
2602 PL_op->op_private |= OPpENTERSUB_DB;
2604 Perl_pp_pushmark(aTHX);
2606 EXTEND(SP, notfound + 5);
2607 PUSHs(lr>0? right: left);
2608 PUSHs(lr>0? left: right);
2609 PUSHs( lr > 0 ? &PL_sv_yes : ( assign ? &PL_sv_undef : &PL_sv_no ));
2611 PUSHs(newSVpvn_flags(AMG_id2name(method + assignshift),
2612 AMG_id2namelen(method + assignshift), SVs_TEMP));
2614 PUSHs(MUTABLE_SV(cv));
2617 if ((PL_op = PL_ppaddr[OP_ENTERSUB](aTHX)))
2625 CATCH_SET(oldcatch);
2632 ans=SvIV(res)<=0; break;
2635 ans=SvIV(res)<0; break;
2638 ans=SvIV(res)>=0; break;
2641 ans=SvIV(res)>0; break;
2644 ans=SvIV(res)==0; break;
2647 ans=SvIV(res)!=0; break;
2650 SvSetSV(left,res); return left;
2652 ans=!SvTRUE(res); break;
2657 } else if (method==copy_amg) {
2659 Perl_croak(aTHX_ "Copy method did not return a reference");
2661 return SvREFCNT_inc(SvRV(res));
2669 Perl_gv_name_set(pTHX_ GV *gv, const char *name, U32 len, U32 flags)
2674 PERL_ARGS_ASSERT_GV_NAME_SET;
2675 PERL_UNUSED_ARG(flags);
2678 Perl_croak(aTHX_ "panic: gv name too long (%"UVuf")", (UV) len);
2680 if (!(flags & GV_ADD) && GvNAME_HEK(gv)) {
2681 unshare_hek(GvNAME_HEK(gv));
2684 PERL_HASH(hash, name, len);
2685 GvNAME_HEK(gv) = share_hek(name, len, hash);
2689 =for apidoc gv_try_downgrade
2691 If the typeglob C<gv> can be expressed more succinctly, by having
2692 something other than a real GV in its place in the stash, replace it
2693 with the optimised form. Basic requirements for this are that C<gv>
2694 is a real typeglob, is sufficiently ordinary, and is only referenced
2695 from its package. This function is meant to be used when a GV has been
2696 looked up in part to see what was there, causing upgrading, but based
2697 on what was found it turns out that the real GV isn't required after all.
2699 If C<gv> is a completely empty typeglob, it is deleted from the stash.
2701 If C<gv> is a typeglob containing only a sufficiently-ordinary constant
2702 sub, the typeglob is replaced with a scalar-reference placeholder that
2703 more compactly represents the same thing.
2709 Perl_gv_try_downgrade(pTHX_ GV *gv)
2715 PERL_ARGS_ASSERT_GV_TRY_DOWNGRADE;
2717 /* XXX Why and where does this leave dangling pointers during global
2719 if (PL_phase == PERL_PHASE_DESTRUCT) return;
2721 if (!(SvREFCNT(gv) == 1 && SvTYPE(gv) == SVt_PVGV && !SvFAKE(gv) &&
2722 !SvOBJECT(gv) && !SvREADONLY(gv) &&
2723 isGV_with_GP(gv) && GvGP(gv) &&
2724 !GvINTRO(gv) && GvREFCNT(gv) == 1 &&
2725 !GvSV(gv) && !GvAV(gv) && !GvHV(gv) && !GvIOp(gv) && !GvFORM(gv) &&
2726 GvEGVx(gv) == gv && (stash = GvSTASH(gv))))
2728 if (SvMAGICAL(gv)) {
2730 /* only backref magic is allowed */
2731 if (SvGMAGICAL(gv) || SvSMAGICAL(gv))
2733 for (mg = SvMAGIC(gv); mg; mg = mg->mg_moremagic) {
2734 if (mg->mg_type != PERL_MAGIC_backref)
2740 HEK *gvnhek = GvNAME_HEK(gv);
2741 (void)hv_delete(stash, HEK_KEY(gvnhek),
2742 HEK_UTF8(gvnhek) ? -HEK_LEN(gvnhek) : HEK_LEN(gvnhek), G_DISCARD);
2743 } else if (GvMULTI(gv) && cv &&
2744 !SvOBJECT(cv) && !SvMAGICAL(cv) && !SvREADONLY(cv) &&
2745 CvSTASH(cv) == stash && CvGV(cv) == gv &&
2746 CvCONST(cv) && !CvMETHOD(cv) && !CvLVALUE(cv) && !CvUNIQUE(cv) &&
2747 !CvNODEBUG(cv) && !CvCLONE(cv) && !CvCLONED(cv) && !CvANON(cv) &&
2748 (namehek = GvNAME_HEK(gv)) &&
2749 (gvp = hv_fetch(stash, HEK_KEY(namehek),
2750 HEK_LEN(namehek)*(HEK_UTF8(namehek) ? -1 : 1), 0)) &&
2752 SV *value = SvREFCNT_inc(CvXSUBANY(cv).any_ptr);
2756 SvFLAGS(gv) = SVt_IV|SVf_ROK;
2757 SvANY(gv) = (XPVGV*)((char*)&(gv->sv_u.svu_iv) -
2758 STRUCT_OFFSET(XPVIV, xiv_iv));
2759 SvRV_set(gv, value);
2766 core_xsub(pTHX_ CV* cv)
2769 "&CORE::%s cannot be called directly", GvNAME(CvGV(cv))
2775 * c-indentation-style: bsd
2777 * indent-tabs-mode: t
2780 * ex: set ts=8 sts=4 sw=4 noet: