X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/cac9886002c78b71182c4087f3db8da5be9364c1..7a6072a8e020194545ae918018728beca4bd5e3b:/mro.c?ds=sidebyside diff --git a/mro.c b/mro.c index 5c4b1e5..1aac225 100644 --- a/mro.c +++ b/mro.c @@ -1,6 +1,7 @@ /* mro.c * * Copyright (c) 2007 Brandon L Black + * Copyright (c) 2007, 2008 Larry Wall and others * * You may distribute under the terms of either the GNU General Public * License or the Artistic License, as specified in the README file. @@ -8,8 +9,10 @@ */ /* - * "Which order shall we go in?" said Frodo. "Eldest first, or quickest first? - * You'll be last either way, Master Peregrin." + * 'Which order shall we go in?' said Frodo. 'Eldest first, or quickest first? + * You'll be last either way, Master Peregrin.' + * + * [p.101 of _The Lord of the Rings_, I/iii: "A Conspiracy Unmasked"] */ /* @@ -21,29 +24,125 @@ These functions are related to the method resolution order of perl classes */ #include "EXTERN.h" +#define PERL_IN_MRO_C #include "perl.h" +static const struct mro_alg dfs_alg = + {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0}; + +SV * +Perl_mro_get_private_data(pTHX_ struct mro_meta *const smeta, + const struct mro_alg *const which) +{ + SV **data; + PERL_ARGS_ASSERT_MRO_GET_PRIVATE_DATA; + + data = (SV **)Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, + which->name, which->length, which->kflags, + HV_FETCH_JUST_SV, NULL, which->hash); + if (!data) + return NULL; + + /* If we've been asked to look up the private data for the current MRO, then + cache it. */ + if (smeta->mro_which == which) + smeta->mro_linear_current = *data; + + return *data; +} + +SV * +Perl_mro_set_private_data(pTHX_ struct mro_meta *const smeta, + const struct mro_alg *const which, SV *const data) +{ + PERL_ARGS_ASSERT_MRO_SET_PRIVATE_DATA; + + if (!smeta->mro_linear_all) { + if (smeta->mro_which == which) { + /* If all we need to store is the current MRO's data, then don't use + memory on a hash with 1 element - store it direct, and signal + this by leaving the would-be-hash NULL. */ + smeta->mro_linear_current = data; + return data; + } else { + HV *const hv = newHV(); + /* Start with 2 buckets. It's unlikely we'll need more. */ + HvMAX(hv) = 1; + smeta->mro_linear_all = hv; + + if (smeta->mro_linear_current) { + /* If we were storing something directly, put it in the hash + before we lose it. */ + Perl_mro_set_private_data(aTHX_ smeta, smeta->mro_which, + smeta->mro_linear_current); + } + } + } + + /* We get here if we're storing more than one linearisation for this stash, + or the linearisation we are storing is not that if its current MRO. */ + + if (smeta->mro_which == which) { + /* If we've been asked to store the private data for the current MRO, + then cache it. */ + smeta->mro_linear_current = data; + } + + if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, + which->name, which->length, which->kflags, + HV_FETCH_ISSTORE, data, which->hash)) { + Perl_croak(aTHX_ "panic: hv_store() failed in set_mro_private_data() " + "for '%.*s' %d", (int) which->length, which->name, + which->kflags); + } + + return data; +} + +const struct mro_alg * +Perl_mro_get_from_name(pTHX_ SV *name) { + SV **data; + + PERL_ARGS_ASSERT_MRO_GET_FROM_NAME; + + data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0, + HV_FETCH_JUST_SV, NULL, 0); + if (!data) + return NULL; + assert(SvTYPE(*data) == SVt_IV); + assert(SvIOK(*data)); + return INT2PTR(const struct mro_alg *, SvUVX(*data)); +} + +void +Perl_mro_register(pTHX_ const struct mro_alg *mro) { + SV *wrapper = newSVuv(PTR2UV(mro)); + + PERL_ARGS_ASSERT_MRO_REGISTER; + + + if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL, + mro->name, mro->length, mro->kflags, + HV_FETCH_ISSTORE, wrapper, mro->hash)) { + SvREFCNT_dec(wrapper); + Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() " + "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags); + } +} + struct mro_meta* Perl_mro_meta_init(pTHX_ HV* stash) { - void* newmeta; + struct mro_meta* newmeta; - assert(stash); + PERL_ARGS_ASSERT_MRO_META_INIT; assert(HvAUX(stash)); assert(!(HvAUX(stash)->xhv_mro_meta)); - Newxz(newmeta, sizeof(struct mro_meta), char); - HvAUX(stash)->xhv_mro_meta = (struct mro_meta*)newmeta; - ((struct mro_meta*)newmeta)->sub_generation = 1; - - /* Manually flag UNIVERSAL as being universal. - This happens early in perl booting (when universal.c - does the newXS calls for UNIVERSAL::*), and infects - other packages as they are added to UNIVERSAL's MRO - */ - if(HvNAMELEN_get(stash) == 9 - && strEQ(HEK_KEY(HvAUX(stash)->xhv_name), "UNIVERSAL")) { - HvMROMETA(stash)->is_universal = 1; - } + Newxz(newmeta, 1, struct mro_meta); + HvAUX(stash)->xhv_mro_meta = newmeta; + newmeta->cache_gen = 1; + newmeta->pkg_gen = 1; + newmeta->mro_which = &dfs_alg; return newmeta; } @@ -54,30 +153,31 @@ Perl_mro_meta_init(pTHX_ HV* stash) struct mro_meta* Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) { - void* newmeta_void; struct mro_meta* newmeta; - assert(smeta); - - Newx(newmeta_void, sizeof(struct mro_meta), char); - newmeta = (struct mro_meta*)newmeta_void; - - newmeta->mro_which = smeta->mro_which; - newmeta->sub_generation = smeta->sub_generation; - newmeta->is_universal = smeta->is_universal; - newmeta->fake = smeta->fake; - newmeta->mro_linear_dfs = smeta->mro_linear_dfs - ? (AV*) SvREFCNT_inc(sv_dup((SV*)smeta->mro_linear_dfs, param)) - : 0; - newmeta->mro_linear_c3 = smeta->mro_linear_c3 - ? (AV*) SvREFCNT_inc(sv_dup((SV*)smeta->mro_linear_c3, param)) - : 0; - newmeta->mro_isarev = smeta->mro_isarev - ? (HV*) SvREFCNT_inc(sv_dup((SV*)smeta->mro_isarev, param)) - : 0; - newmeta->mro_nextmethod = smeta->mro_nextmethod - ? (HV*) SvREFCNT_inc(sv_dup((SV*)smeta->mro_nextmethod, param)) - : 0; + PERL_ARGS_ASSERT_MRO_META_DUP; + + Newx(newmeta, 1, struct mro_meta); + Copy(smeta, newmeta, 1, struct mro_meta); + + if (newmeta->mro_linear_all) { + newmeta->mro_linear_all + = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_linear_all, param)); + /* This is just acting as a shortcut pointer, and will be automatically + updated on the first get. */ + newmeta->mro_linear_current = NULL; + } else if (newmeta->mro_linear_current) { + /* Only the current MRO is stored, so this owns the data. */ + newmeta->mro_linear_current + = sv_dup_inc((const SV *)newmeta->mro_linear_current, param); + } + + if (newmeta->mro_nextmethod) + newmeta->mro_nextmethod + = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_nextmethod, param)); + if (newmeta->isa) + newmeta->isa + = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->isa, param)); return newmeta; } @@ -92,227 +192,188 @@ the given stash. The return value is a read-only AV*. C should be 0 (it is used internally in this function's recursion). +You are responsible for C on the +return value if you plan to store it anywhere +semi-permanently (otherwise it might be deleted +out from under you the next time the cache is +invalidated). + =cut */ -AV* -Perl_mro_get_linear_isa_dfs(pTHX_ HV *stash, I32 level) +static AV* +S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level) { AV* retval; GV** gvp; GV* gv; AV* av; - SV** svp; - I32 items; - AV* subrv; - SV** subrv_p; - I32 subrv_items; - const char* stashname; + const HEK* stashhek; struct mro_meta* meta; + SV *our_name; + HV *stored = NULL; - assert(stash); + PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS; assert(HvAUX(stash)); - stashname = HvNAME_get(stash); - if (!stashname) - Perl_croak(aTHX_ - "Can't linearize anonymous symbol table"); + stashhek + = HvAUX(stash)->xhv_name && HvENAME_HEK_NN(stash) + ? HvENAME_HEK_NN(stash) + : HvNAME_HEK(stash); + + if (!stashhek) + Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); if (level > 100) Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", - stashname); + HEK_KEY(stashhek)); meta = HvMROMETA(stash); - if((retval = meta->mro_linear_dfs)) { - /* return cache if valid */ + + /* return cache if valid */ + if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) { return retval; } /* not in cache, make a new one */ - retval = newAV(); - av_push(retval, newSVpv(stashname, 0)); /* add ourselves at the top */ + retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); + /* We use this later in this function, but don't need a reference to it + beyond the end of this function, so reference count is fine. */ + our_name = newSVhek(stashhek); + av_push(retval, our_name); /* add ourselves at the top */ + + /* fetch our @ISA */ gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; - if(av) { - HV* stored = (HV*)sv_2mortal((SV*)newHV()); - svp = AvARRAY(av); - items = AvFILLp(av) + 1; + /* "stored" is used to keep track of all of the classnames we have added to + the MRO so far, so we can do a quick exists check and avoid adding + duplicate classnames to the MRO as we go. + It's then retained to be re-used as a fast lookup for ->isa(), by adding + our own name and "UNIVERSAL" to it. */ + + if(av && AvFILLp(av) >= 0) { + + SV **svp = AvARRAY(av); + I32 items = AvFILLp(av) + 1; + + /* foreach(@ISA) */ while (items--) { SV* const sv = *svp++; HV* const basestash = gv_stashsv(sv, 0); + SV *const *subrv_p; + I32 subrv_items; if (!basestash) { - if(!hv_exists_ent(stored, sv, 0)) { - av_push(retval, newSVsv(sv)); - hv_store_ent(stored, sv, &PL_sv_undef, 0); - } + /* if no stash exists for this @ISA member, + simply add it to the MRO and move on */ + subrv_p = &sv; + subrv_items = 1; } else { - subrv = mro_get_linear_isa_dfs(basestash, level + 1); - subrv_p = AvARRAY(subrv); - subrv_items = AvFILLp(subrv) + 1; - while(subrv_items--) { - SV* subsv = *subrv_p++; - if(!hv_exists_ent(stored, subsv, 0)) { - av_push(retval, newSVsv(subsv)); - hv_store_ent(stored, subsv, &PL_sv_undef, 0); - } - } - } + /* otherwise, recurse into ourselves for the MRO + of this @ISA member, and append their MRO to ours. + The recursive call could throw an exception, which + has memory management implications here, hence the use of + the mortal. */ + const AV *const subrv + = mro_get_linear_isa_dfs(basestash, level + 1); + + subrv_p = AvARRAY(subrv); + subrv_items = AvFILLp(subrv) + 1; + } + if (stored) { + while(subrv_items--) { + SV *const subsv = *subrv_p++; + /* LVALUE fetch will create a new undefined SV if necessary + */ + HE *const he = hv_fetch_ent(stored, subsv, 1, 0); + assert(he); + if(HeVAL(he) != &PL_sv_undef) { + /* It was newly created. Steal it for our new SV, and + replace it in the hash with the "real" thing. */ + SV *const val = HeVAL(he); + HEK *const key = HeKEY_hek(he); + + HeVAL(he) = &PL_sv_undef; + /* Save copying by making a shared hash key scalar. We + inline this here rather than calling + Perl_newSVpvn_share because we already have the + scalar, and we already have the hash key. */ + assert(SvTYPE(val) == SVt_NULL); + sv_upgrade(val, SVt_PV); + SvPV_set(val, HEK_KEY(share_hek_hek(key))); + SvCUR_set(val, HEK_LEN(key)); + SvREADONLY_on(val); + SvFAKE_on(val); + SvPOK_on(val); + if (HEK_UTF8(key)) + SvUTF8_on(val); + + av_push(retval, val); + } + } + } else { + /* We are the first (or only) parent. We can short cut the + complexity above, because our @ISA is simply us prepended + to our parent's @ISA, and our ->isa cache is simply our + parent's, with our name added. */ + /* newSVsv() is slow. This code is only faster if we can avoid + it by ensuring that SVs in the arrays are shared hash key + scalar SVs, because we can "copy" them very efficiently. + Although to be fair, we can't *ensure* this, as a reference + to the internal array is returned by mro::get_linear_isa(), + so we'll have to be defensive just in case someone faffed + with it. */ + if (basestash) { + SV **svp; + stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa))); + av_extend(retval, subrv_items); + AvFILLp(retval) = subrv_items; + svp = AvARRAY(retval); + while(subrv_items--) { + SV *const val = *subrv_p++; + *++svp = SvIsCOW_shared_hash(val) + ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val))) + : newSVsv(val); + } + } else { + /* They have no stash. So create ourselves an ->isa cache + as if we'd copied it from what theirs should be. */ + stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); + (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); + av_push(retval, + newSVhek(HeKEY_hek(hv_store_ent(stored, sv, + &PL_sv_undef, 0)))); + } + } } + } else { + /* We have no parents. */ + stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); + (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); } - SvREADONLY_on(retval); - meta->mro_linear_dfs = retval; - return retval; -} - -/* -=for apidoc mro_get_linear_isa_c3 - -Returns the C3 linearization of @ISA -the given stash. The return value is a read-only AV*. -C should be 0 (it is used internally in this -function's recursion). + (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); -=cut -*/ + SvREFCNT_inc_simple_void_NN(stored); + SvTEMP_off(stored); + SvREADONLY_on(stored); -AV* -Perl_mro_get_linear_isa_c3(pTHX_ HV* stash, I32 level) -{ - AV* retval; - GV** gvp; - GV* gv; - AV* isa; - const char* stashname; - STRLEN stashname_len; - struct mro_meta* meta; + meta->isa = stored; - assert(stash); - assert(HvAUX(stash)); - - stashname = HvNAME_get(stash); - stashname_len = HvNAMELEN_get(stash); - if (!stashname) - Perl_croak(aTHX_ - "Can't linearize anonymous symbol table"); - - if (level > 100) - Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", - stashname); - - meta = HvMROMETA(stash); - if((retval = meta->mro_linear_c3)) { - /* return cache if valid */ - return retval; - } - - /* not in cache, make a new one */ - - retval = newAV(); - av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */ - - gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); - isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; - - if(isa && AvFILLp(isa) >= 0) { - SV** seqs_ptr; - I32 seqs_items; - HV* tails = (HV*)sv_2mortal((SV*)newHV()); - AV* seqs = (AV*)sv_2mortal((SV*)newAV()); - I32 items = AvFILLp(isa) + 1; - SV** isa_ptr = AvARRAY(isa); - while(items--) { - AV* isa_lin; - SV* isa_item = *isa_ptr++; - HV* isa_item_stash = gv_stashsv(isa_item, 0); - if(!isa_item_stash) { - isa_lin = newAV(); - av_push(isa_lin, newSVsv(isa_item)); - } - else { - isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */ - } - av_push(seqs, (SV*)av_make(AvFILLp(isa_lin)+1, AvARRAY(isa_lin))); - } - av_push(seqs, (SV*)av_make(AvFILLp(isa)+1, AvARRAY(isa))); - - seqs_ptr = AvARRAY(seqs); - seqs_items = AvFILLp(seqs) + 1; - while(seqs_items--) { - AV* seq = (AV*)*seqs_ptr++; - I32 seq_items = AvFILLp(seq); - if(seq_items > 0) { - SV** seq_ptr = AvARRAY(seq) + 1; - while(seq_items--) { - SV* seqitem = *seq_ptr++; - HE* he = hv_fetch_ent(tails, seqitem, 0, 0); - if(!he) { - hv_store_ent(tails, seqitem, newSViv(1), 0); - } - else { - SV* val = HeVAL(he); - sv_inc(val); - } - } - } - } - - while(1) { - SV* seqhead = NULL; - SV* cand = NULL; - SV* winner = NULL; - SV* val; - HE* tail_entry; - AV* seq; - SV** avptr = AvARRAY(seqs); - items = AvFILLp(seqs)+1; - while(items--) { - SV** svp; - seq = (AV*)*avptr++; - if(AvFILLp(seq) < 0) continue; - svp = av_fetch(seq, 0, 0); - seqhead = *svp; - if(!winner) { - cand = seqhead; - if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) - && (val = HeVAL(tail_entry)) - && (SvIVx(val) > 0)) - continue; - winner = newSVsv(cand); - av_push(retval, winner); - } - if(!sv_cmp(seqhead, winner)) { - - /* this is basically shift(@seq) in void context */ - SvREFCNT_dec(*AvARRAY(seq)); - *AvARRAY(seq) = &PL_sv_undef; - AvARRAY(seq) = AvARRAY(seq) + 1; - AvMAX(seq)--; - AvFILLp(seq)--; - - if(AvFILLp(seq) < 0) continue; - svp = av_fetch(seq, 0, 0); - seqhead = *svp; - tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); - val = HeVAL(tail_entry); - sv_dec(val); - } - } - if(!cand) break; - if(!winner) { - SvREFCNT_dec(retval); - Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " - "merging failed on parent '%"SVf"'", stashname, SVfARG(cand)); - } - } - } + /* now that we're past the exception dangers, grab our own reference to + the AV we're about to use for the result. The reference owned by the + mortals' stack will be released soon, so everything will balance. */ + SvREFCNT_inc_simple_void_NN(retval); + SvTEMP_off(retval); + /* we don't want anyone modifying the cache entry but us, + and we do so by replacing it completely */ SvREADONLY_on(retval); - meta->mro_linear_c3 = retval; - return retval; + + return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg, + MUTABLE_SV(retval))); } /* @@ -324,34 +385,78 @@ dependant upon which MRO is in effect for that stash. The return value is a read-only AV*. +You are responsible for C on the +return value if you plan to store it anywhere +semi-permanently (otherwise it might be deleted +out from under you the next time the cache is +invalidated). + =cut */ AV* Perl_mro_get_linear_isa(pTHX_ HV *stash) { struct mro_meta* meta; - assert(stash); - assert(HvAUX(stash)); + AV *isa; + + PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA; + if(!SvOOK(stash)) + Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); meta = HvMROMETA(stash); - if(meta->mro_which == MRO_DFS) { - return mro_get_linear_isa_dfs(stash, 0); - } else if(meta->mro_which == MRO_C3) { - return mro_get_linear_isa_c3(stash, 0); - } else { + if (!meta->mro_which) Perl_croak(aTHX_ "panic: invalid MRO!"); + isa = meta->mro_which->resolve(aTHX_ stash, 0); + + if (!meta->isa) { + HV *const isa_hash = newHV(); + /* Linearisation didn't build it for us, so do it here. */ + SV *const *svp = AvARRAY(isa); + SV *const *const svp_end = svp + AvFILLp(isa) + 1; + const HEK *canon_name = HvENAME_HEK(stash); + if (!canon_name) canon_name = HvNAME_HEK(stash); + + while (svp < svp_end) { + (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0); + } + + (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name), + HEK_LEN(canon_name), HEK_FLAGS(canon_name), + HV_FETCH_ISSTORE, &PL_sv_undef, + HEK_HASH(canon_name)); + (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0); + + SvREADONLY_on(isa_hash); + + meta->isa = isa_hash; } + + return isa; } /* =for apidoc mro_isa_changed_in -Takes the neccesary steps (cache invalidations, mostly) +Takes the necessary steps (cache invalidations, mostly) when the @ISA of the given package has changed. Invoked by the C magic, should not need to invoke directly. =cut */ + +/* Macro to avoid repeating the code five times. */ +#define CLEAR_LINEAR(mEta) \ + if (mEta->mro_linear_all) { \ + SvREFCNT_dec(MUTABLE_SV(mEta->mro_linear_all)); \ + mEta->mro_linear_all = NULL; \ + /* This is just acting as a shortcut pointer. */ \ + mEta->mro_linear_current = NULL; \ + } else if (mEta->mro_linear_current) { \ + /* Only the current MRO is stored, so this owns the data. */ \ + SvREFCNT_dec(mEta->mro_linear_current); \ + mEta->mro_linear_current = NULL; \ + } + void Perl_mro_isa_changed_in(pTHX_ HV* stash) { @@ -361,567 +466,720 @@ Perl_mro_isa_changed_in(pTHX_ HV* stash) HE* iter; SV** svp; I32 items; - struct mro_meta* meta; - char* stashname; + bool is_universal; + struct mro_meta * meta; + HV *isa = NULL; + + const char * const stashname = HvENAME_get(stash); + const STRLEN stashname_len = HvENAMELEN_get(stash); + + PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN; + + if(!stashname) + Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table"); - stashname = HvNAME_get(stash); /* wipe out the cached linearizations for this stash */ meta = HvMROMETA(stash); - SvREFCNT_dec((SV*)meta->mro_linear_dfs); - SvREFCNT_dec((SV*)meta->mro_linear_c3); - meta->mro_linear_dfs = NULL; - meta->mro_linear_c3 = NULL; + CLEAR_LINEAR(meta); + if (meta->isa) { + /* Steal it for our own purposes. */ + isa = (HV *)sv_2mortal((SV *)meta->isa); + meta->isa = NULL; + } + + /* Inc the package generation, since our @ISA changed */ + meta->pkg_gen++; /* Wipe the global method cache if this package is UNIVERSAL or one of its parents */ - if(meta->is_universal) - PL_sub_generation++; - /* Wipe the local method cache otherwise */ - else - meta->sub_generation++; + svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); + isarev = svp ? MUTABLE_HV(*svp) : NULL; + + if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) + || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { + PL_sub_generation++; + is_universal = TRUE; + } + else { /* Wipe the local method cache otherwise */ + meta->cache_gen++; + is_universal = FALSE; + } /* wipe next::method cache too */ if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); - + /* Iterate the isarev (classes that are our children), - wiping out their linearization and method caches */ - if((isarev = meta->mro_isarev)) { - hv_iterinit(isarev); + wiping out their linearization, method and isa caches + and upating PL_isarev. */ + if(isarev) { + HV *isa_hashes = NULL; + + /* We have to iterate through isarev twice to avoid a chicken and + * egg problem: if A inherits from B and both are in isarev, A might + * be processed before B and use B’s previous linearisation. + */ + + /* First iteration: Wipe everything, but stash away the isa hashes + * since we still need them for updating PL_isarev. + */ + + if(hv_iterinit(isarev)) { + /* Only create the hash if we need it; i.e., if isarev has + any elements. */ + isa_hashes = (HV *)sv_2mortal((SV *)newHV()); + } while((iter = hv_iternext(isarev))) { - SV* revkey = hv_iterkeysv(iter); - HV* revstash = gv_stashsv(revkey, 0); - struct mro_meta* revmeta = HvMROMETA(revstash); - SvREFCNT_dec((SV*)revmeta->mro_linear_dfs); - SvREFCNT_dec((SV*)revmeta->mro_linear_c3); - revmeta->mro_linear_dfs = NULL; - revmeta->mro_linear_c3 = NULL; - if(!meta->is_universal) - revmeta->sub_generation++; + I32 len; + const char* const revkey = hv_iterkey(iter, &len); + HV* revstash = gv_stashpvn(revkey, len, 0); + struct mro_meta* revmeta; + + if(!revstash) continue; + revmeta = HvMROMETA(revstash); + CLEAR_LINEAR(revmeta); + if(!is_universal) + revmeta->cache_gen++; if(revmeta->mro_nextmethod) hv_clear(revmeta->mro_nextmethod); + + (void) + hv_store( + isa_hashes, (const char*)&revstash, sizeof(HV *), + revmeta->isa ? (SV *)revmeta->isa : &PL_sv_undef, 0 + ); + revmeta->isa = NULL; + } + + /* Second pass: Update PL_isarev. We can just use isa_hashes to + * avoid another round of stash lookups. */ + + /* isarev might be deleted from PL_isarev during this loop, so hang + * on to it. */ + SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)isarev)); + + if(isa_hashes) { + hv_iterinit(isa_hashes); + while((iter = hv_iternext(isa_hashes))) { + HV* const revstash = *(HV **)HEK_KEY(HeKEY_hek(iter)); + HV * const isa = (HV *)HeVAL(iter); + const HEK *namehek; + + /* We're starting at the 2nd element, skipping revstash */ + linear_mro = mro_get_linear_isa(revstash); + svp = AvARRAY(linear_mro) + 1; + items = AvFILLp(linear_mro); + + namehek = HvENAME_HEK(revstash); + if (!namehek) namehek = HvNAME_HEK(revstash); + + while (items--) { + SV* const sv = *svp++; + HV* mroisarev; + + HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); + + /* That fetch should not fail. But if it had to create + a new SV for us, then will need to upgrade it to an + HV (which sv_upgrade() can now do for us). */ + + mroisarev = MUTABLE_HV(HeVAL(he)); + + SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); + + /* This hash only ever contains PL_sv_yes. Storing it + over itself is almost as cheap as calling hv_exists, + so on aggregate we expect to save time by not making + two calls to the common HV code for the case where + it doesn't exist. */ + + (void) + hv_store( + mroisarev, HEK_KEY(namehek), HEK_LEN(namehek), + &PL_sv_yes, 0 + ); + } + + if((SV *)isa != &PL_sv_undef) + mro_clean_isarev( + isa, HEK_KEY(namehek), HEK_LEN(namehek), + HvMROMETA(revstash)->isa + ); + } } } - /* we're starting at the 2nd element, skipping ourselves here */ + /* Now iterate our MRO (parents), adding ourselves and everything from + our isarev to their isarev. + */ + + /* We're starting at the 2nd element, skipping ourselves here */ linear_mro = mro_get_linear_isa(stash); svp = AvARRAY(linear_mro) + 1; items = AvFILLp(linear_mro); + while (items--) { SV* const sv = *svp++; - struct mro_meta* mrometa; HV* mroisarev; - HV* mrostash = gv_stashsv(sv, 0); - if(!mrostash) { - mrostash = gv_stashsv(sv, GV_ADD); - /* - We created the package on the fly, so - that we could store isarev information. - This flag lets gv_fetchmeth know about it, - so that it can still generate the very useful - "Can't locate package Foo for @Bar::ISA" warning. - */ - HvMROMETA(mrostash)->fake = 1; - } + HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); + + /* That fetch should not fail. But if it had to create a new SV for + us, then will need to upgrade it to an HV (which sv_upgrade() can + now do for us. */ - mrometa = HvMROMETA(mrostash); - mroisarev = mrometa->mro_isarev; + mroisarev = MUTABLE_HV(HeVAL(he)); - /* is_universal is viral */ - if(meta->is_universal) - mrometa->is_universal = 1; + SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); - if(!mroisarev) - mroisarev = mrometa->mro_isarev = newHV(); + /* This hash only ever contains PL_sv_yes. Storing it over itself is + almost as cheap as calling hv_exists, so on aggregate we expect to + save time by not making two calls to the common HV code for the + case where it doesn't exist. */ + + (void)hv_store(mroisarev, stashname, stashname_len, &PL_sv_yes, 0); + } - if(!hv_exists(mroisarev, stashname, strlen(stashname))) - hv_store(mroisarev, stashname, strlen(stashname), &PL_sv_yes, 0); + /* Delete our name from our former parents’ isarevs. */ + if(isa && HvARRAY(isa)) + mro_clean_isarev(isa, stashname, stashname_len, meta->isa); +} - if(isarev) { - hv_iterinit(isarev); - while((iter = hv_iternext(isarev))) { - SV* revkey = hv_iterkeysv(iter); - if(!hv_exists_ent(mroisarev, revkey, 0)) - hv_store_ent(mroisarev, revkey, &PL_sv_yes, 0); +/* Deletes name from all the isarev entries listed in isa */ +STATIC void +S_mro_clean_isarev(pTHX_ HV * const isa, const char * const name, + const STRLEN len, HV * const exceptions) +{ + HE* iter; + + PERL_ARGS_ASSERT_MRO_CLEAN_ISAREV; + + /* Delete our name from our former parents’ isarevs. */ + if(isa && HvARRAY(isa) && hv_iterinit(isa)) { + SV **svp; + while((iter = hv_iternext(isa))) { + I32 klen; + const char * const key = hv_iterkey(iter, &klen); + if(exceptions && hv_exists(exceptions, key, klen)) continue; + svp = hv_fetch(PL_isarev, key, klen, 0); + if(svp) { + HV * const isarev = (HV *)*svp; + (void)hv_delete(isarev, name, len, G_DISCARD); + if(!HvARRAY(isarev) || !HvKEYS(isarev)) + (void)hv_delete(PL_isarev, key, klen, G_DISCARD); } } } } /* -=for apidoc mro_method_changed_in +=for apidoc mro_package_moved -Like C, but invalidates method -caching on any child classes of the given stash, so -that they might notice the changes in this one. +Call this function to signal to a stash that it has been assigned to +another spot in the stash hierarchy. C is the stash that has been +assigned. C is the stash it replaces, if any. C is the glob +that is actually being assigned to. C and C are the +full name of the GV. If these last two arguments are omitted, they can be +inferred from C. C can be omitted if C is given. -Ideally, all instances of C in -the perl source should be replaced by calls to this. -Some already are, but some are more difficult to -replace. +This can also be called with a null first argument to +indicate that C has been deleted. -Perl has always had problems with method caches -getting out of sync when one directly manipulates -stashes via things like C<%{Foo::} = %{Bar::}> or -C<${Foo::}{bar} = ...> or the equivalent. If -you do this in core or XS code, call this afterwards -on the destination stash to get things back in sync. +This function invalidates isa caches on the old stash, on all subpackages +nested inside it, and on the subclasses of all those, including +non-existent packages that have corresponding entries in C. -If you're doing such a thing from pure perl, use -C, which -just calls this. +It also sets the effective names (C) on all the stashes as +appropriate. =cut */ void -Perl_mro_method_changed_in(pTHX_ HV *stash) +Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash, + const GV *gv, const char *newname, + I32 newname_len) { - struct mro_meta* meta = HvMROMETA(stash); - HV* isarev; + HV *stashes; HE* iter; - /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, - invalidate all method caches globally */ - if(meta->is_universal) { - PL_sub_generation++; - return; - } - - /* else, invalidate the method caches of all child classes, - but not itself */ - if((isarev = meta->mro_isarev)) { - hv_iterinit(isarev); - while((iter = hv_iternext(isarev))) { - SV* revkey = hv_iterkeysv(iter); - HV* revstash = gv_stashsv(revkey, 0); - struct mro_meta* mrometa = HvMROMETA(revstash); - mrometa->sub_generation++; - if(mrometa->mro_nextmethod) - hv_clear(mrometa->mro_nextmethod); - } + assert(stash || oldstash); + assert(gv || newname); + + /* Determine the name of the location that stash was assigned to + * or from which oldstash was removed. + * + * We cannot reliably use the name in oldstash, because it may have + * been deleted from the location in the symbol table that its name + * suggests, as in this case: + * + * $globref = \*foo::bar::; + * Symbol::delete_package("foo"); + * *$globref = \%baz::; + * *$globref = *frelp::; + * # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0) + * + * If newname is not null, then we trust that the caller gave us the + * right name. Otherwise, we get it from the gv. But if the gv is not + * in the symbol table, then we just return. + */ + if(!newname && gv) { + SV * const namesv = sv_newmortal(); + STRLEN len; + gv_fullname4(namesv, gv, NULL, 0); + if(gv_fetchsv(namesv, GV_NOADD_NOINIT, SVt_PVGV) != gv) return; + newname = SvPV_const(namesv, len); + newname_len = len - 2; /* skip trailing :: */ } -} - -/* These two are static helpers for next::method and friends, - and re-implement a bunch of the code from pp_caller() in - a more efficient manner for this particular usage. -*/ - -STATIC I32 -__dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { - I32 i; - for (i = startingblock; i >= 0; i--) { - if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; + if(newname_len < 0) newname_len = -newname_len; + + /* Get a list of all the affected classes. */ + /* We cannot simply pass them all to mro_isa_changed_in to avoid + the list, as that function assumes that only one package has + changed. It does not work with: + + @foo::ISA = qw( B B::B ); + *B:: = delete $::{"A::"}; + + as neither B nor B::B can be updated before the other, since they + will reset caches on foo, which will see either B or B::B with the + wrong name. The names must be set on *all* affected stashes before + we do anything else. (And linearisations must be cleared, too.) + */ + stashes = (HV *) sv_2mortal((SV *)newHV()); + mro_gather_and_rename( + stashes, (HV *) sv_2mortal((SV *)newHV()), + stash, oldstash, newname, newname_len + ); + + /* Once the caches have been wiped on all the classes, call + mro_isa_changed_in on each. */ + hv_iterinit(stashes); + while((iter = hv_iternext(stashes))) { + HV * const stash = *(HV **)HEK_KEY(HeKEY_hek(iter)); + if(HvENAME(stash)) { + /* We have to restore the original meta->isa (that + mro_gather_and_rename set aside for us) this way, in case + one class in this list is a superclass of a another class + that we have already encountered. In such a case, meta->isa + will have been overwritten without old entries being deleted + from PL_isarev. */ + struct mro_meta * const meta = HvMROMETA(stash); + if(meta->isa != (HV *)HeVAL(iter)){ + SvREFCNT_dec(meta->isa); + meta->isa + = HeVAL(iter) == &PL_sv_yes + ? NULL + : (HV *)HeVAL(iter); + HeVAL(iter) = NULL; /* We donated our reference count. */ + } + mro_isa_changed_in(stash); + } } - return i; } -STATIC SV* -__nextcan(pTHX_ SV* self, I32 throw_nomethod) +void +S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes, + HV *stash, HV *oldstash, const char *name, + I32 namlen) { - register I32 cxix; - register const PERL_CONTEXT *ccstack = cxstack; - const PERL_SI *top_si = PL_curstackinfo; - HV* selfstash; - GV* cvgv; - SV *stashname; - const char *fq_subname; - const char *subname; - STRLEN fq_subname_len; - STRLEN stashname_len; - STRLEN subname_len; - SV* sv; - GV** gvp; - AV* linear_av; - SV** linear_svp; - SV* linear_sv; - HV* curstash; - GV* candidate = NULL; - CV* cand_cv = NULL; - const char *hvname; - I32 items; - struct mro_meta* selfmeta; - HV* nmcache; - HE* cache_entry; - - if(sv_isobject(self)) - selfstash = SvSTASH(SvRV(self)); - else - selfstash = gv_stashsv(self, 0); - - assert(selfstash); - - hvname = HvNAME_get(selfstash); - if (!hvname) - Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); - - cxix = __dopoptosub_at(cxstack, cxstack_ix); - - /* This block finds the contextually-enclosing fully-qualified subname, - much like looking at (caller($i))[3] until you find a real sub that - isn't ANON, etc */ - for (;;) { - /* we may be in a higher stacklevel, so dig down deeper */ - while (cxix < 0) { - if(top_si->si_type == PERLSI_MAIN) - Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); - top_si = top_si->si_prev; - ccstack = top_si->si_cxstack; - cxix = __dopoptosub_at(ccstack, top_si->si_cxix); - } - - if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB - || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { - cxix = __dopoptosub_at(ccstack, cxix - 1); - continue; - } - - { - const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); - if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { - if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { - cxix = dbcxix; - continue; - } - } - } - - cvgv = CvGV(ccstack[cxix].blk_sub.cv); - - if(!isGV(cvgv)) { - cxix = __dopoptosub_at(ccstack, cxix - 1); - continue; - } - - /* we found a real sub here */ - sv = sv_2mortal(newSV(0)); - - gv_efullname3(sv, cvgv, NULL); - - fq_subname = SvPVX(sv); - fq_subname_len = SvCUR(sv); - - subname = strrchr(fq_subname, ':'); - if(!subname) - Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); - - subname++; - subname_len = fq_subname_len - (subname - fq_subname); - if(subname_len == 8 && strEQ(subname, "__ANON__")) { - cxix = __dopoptosub_at(ccstack, cxix - 1); - continue; - } - break; + register XPVHV* xhv; + register HE *entry; + I32 riter = -1; + const bool stash_had_name = stash && HvENAME(stash); + HV *seen = NULL; + HV *isarev = NULL; + SV **svp; + + PERL_ARGS_ASSERT_MRO_GATHER_AND_RENAME; + + /* We use the seen_stashes hash to keep track of which packages have + been encountered so far. This must be separate from the main list of + stashes, as we need to distinguish between stashes being assigned + and stashes being replaced/deleted. (A nested stash can be on both + sides of an assignment. We cannot simply skip iterating through a + stash on the right if we have seen it on the left, as it will not + get its ename assigned to it.) + + To avoid allocating extra SVs, instead of a bitfield we can make + bizarre use of immortals: + + &PL_sv_undef: seen on the left (oldstash) + &PL_sv_no : seen on the right (stash) + &PL_sv_yes : seen on both sides + + */ + + if(oldstash) { + /* Add to the big list. */ + struct mro_meta * meta; + HE * const entry + = (HE *) + hv_common( + seen_stashes, NULL, (const char *)&oldstash, sizeof(HV *), 0, + HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 + ); + if(HeVAL(entry) == &PL_sv_undef || HeVAL(entry) == &PL_sv_yes) { + oldstash = NULL; + goto check_stash; + } + HeVAL(entry) + = HeVAL(entry) == &PL_sv_no ? &PL_sv_yes : &PL_sv_undef; + meta = HvMROMETA(oldstash); + (void) + hv_store( + stashes, (const char *)&oldstash, sizeof(HV *), + meta->isa + ? SvREFCNT_inc_simple_NN((SV *)meta->isa) + : &PL_sv_yes, + 0 + ); + CLEAR_LINEAR(meta); + + /* Update the effective name. */ + if(HvENAME_get(oldstash)) { + const HEK * const enamehek = HvENAME_HEK(oldstash); + if(PL_stashcache) + (void) + hv_delete(PL_stashcache, name, namlen, G_DISCARD); + hv_ename_delete(oldstash, name, namlen); + + /* If the name deletion caused a name change, then we are not + * going to call mro_isa_changed_in with this name (and not at all + * if it has become anonymous) so we need to delete old isarev + * entries here, both those in the superclasses and this class’s + * own list of subclasses. We simply delete the latter from + * from PL_isarev, since we still need it. hv_delete mortifies it + * for us, so sv_2mortal is not necessary. */ + if(HvENAME_HEK(oldstash) != enamehek) { + if(meta->isa && HvARRAY(meta->isa)) + mro_clean_isarev(meta->isa, name, namlen, NULL); + isarev = (HV *)hv_delete(PL_isarev, name, namlen, 0); + } + } } - - /* If we made it to here, we found our context */ - - selfmeta = HvMROMETA(selfstash); - if(!(nmcache = selfmeta->mro_nextmethod)) { - nmcache = selfmeta->mro_nextmethod = newHV(); + check_stash: + if(stash) { + hv_ename_add(stash, name, namlen); + + /* Add it to the big list if it needs + * mro_isa_changed_in called on it. That happens if it was + * detached from the symbol table (so it had no HvENAME) before + * being assigned to the spot named by the ‘name’ variable, because + * its cached isa linerisation is now stale (the effective name + * having changed), and subclasses will then use that cache when + * mro_package_moved calls mro_isa_changed_in. (See + * [perl #77358].) + * + * If it did have a name, then its previous name is still + * used in isa caches, and there is no need for + * mro_package_moved to call mro_isa_changed_in. + */ + + entry + = (HE *) + hv_common( + seen_stashes, NULL, (const char *)&stash, sizeof(HV *), 0, + HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 + ); + if(HeVAL(entry) == &PL_sv_yes || HeVAL(entry) == &PL_sv_no) + stash = NULL; + else { + HeVAL(entry) + = HeVAL(entry) == &PL_sv_undef ? &PL_sv_yes : &PL_sv_no; + if(!stash_had_name) + { + struct mro_meta * const meta = HvMROMETA(stash); + (void) + hv_store( + stashes, (const char *)&stash, sizeof(HV *), + meta->isa + ? SvREFCNT_inc_simple_NN((SV *)meta->isa) + : &PL_sv_yes, + 0 + ); + CLEAR_LINEAR(meta); + } + } } - if((cache_entry = hv_fetch_ent(nmcache, sv, 0, 0))) { - SV* val = HeVAL(cache_entry); - if(val == &PL_sv_undef) { - if(throw_nomethod) - Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); + if(!stash && !oldstash) + /* Both stashes have been encountered already. */ + return; + + /* Add all the subclasses to the big list. */ + if( + isarev + || ( + (svp = hv_fetch(PL_isarev, name, namlen, 0)) + && (isarev = MUTABLE_HV(*svp)) + ) + ) { + HE *iter; + hv_iterinit(isarev); + while((iter = hv_iternext(isarev))) { + I32 len; + const char* const revkey = hv_iterkey(iter, &len); + HV* revstash = gv_stashpvn(revkey, len, 0); + struct mro_meta * meta; + + if(!revstash) continue; + meta = HvMROMETA(revstash); + (void) + hv_store( + stashes, (const char *)&revstash, sizeof(HV *), + meta->isa + ? SvREFCNT_inc_simple_NN((SV *)meta->isa) + : &PL_sv_yes, + 0 + ); + CLEAR_LINEAR(meta); } - return val; } - /* beyond here is just for cache misses, so perf isn't as critical */ - - stashname_len = subname - fq_subname - 2; - stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len)); - - linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ - - linear_svp = AvARRAY(linear_av); - items = AvFILLp(linear_av) + 1; + if( + (!stash || !HvARRAY(stash)) && (!oldstash || !HvARRAY(oldstash)) + ) return; + + /* This is partly based on code in hv_iternext_flags. We are not call- + ing that here, as we want to avoid resetting the hash iterator. */ + + /* Skip the entire loop if the hash is empty. */ + if(oldstash && HvUSEDKEYS(oldstash)) { + xhv = (XPVHV*)SvANY(oldstash); + seen = (HV *) sv_2mortal((SV *)newHV()); + + /* Iterate through entries in the oldstash, adding them to the + list, meanwhile doing the equivalent of $seen{$key} = 1. + */ + + while (++riter <= (I32)xhv->xhv_max) { + entry = (HvARRAY(oldstash))[riter]; + + /* Iterate through the entries in this list */ + for(; entry; entry = HeNEXT(entry)) { + const char* key; + I32 len; + + /* If this entry is not a glob, ignore it. + Try the next. */ + if (!isGV(HeVAL(entry))) continue; + + key = hv_iterkey(entry, &len); + if(len > 1 && key[len-2] == ':' && key[len-1] == ':') { + HV * const oldsubstash = GvHV(HeVAL(entry)); + SV ** const stashentry + = stash ? hv_fetch(stash, key, len, 0) : NULL; + HV *substash = NULL; + + /* Avoid main::main::main::... */ + if(oldsubstash == oldstash) continue; + + if( + ( + stashentry && *stashentry + && (substash = GvHV(*stashentry)) + ) + || (oldsubstash && HvENAME_get(oldsubstash)) + ) + { + /* Add :: and the key (minus the trailing ::) + to newname. */ + SV *namesv + = newSVpvn_flags(name, namlen, SVs_TEMP); + { + const char *name; + STRLEN namlen; + sv_catpvs(namesv, "::"); + sv_catpvn(namesv, key, len-2); + name = SvPV_const(namesv, namlen); + mro_gather_and_rename( + stashes, seen_stashes, + substash, oldsubstash, name, namlen + ); + } + } + + (void)hv_store(seen, key, len, &PL_sv_yes, 0); + } + } + } + } - while (items--) { - linear_sv = *linear_svp++; - assert(linear_sv); - if(sv_eq(linear_sv, stashname)) - break; + /* Skip the entire loop if the hash is empty. */ + if (stash && HvUSEDKEYS(stash)) { + xhv = (XPVHV*)SvANY(stash); + riter = -1; + + /* Iterate through the new stash, skipping $seen{$key} items, + calling mro_gather_and_rename(stashes,seen,entry,NULL, ...). */ + while (++riter <= (I32)xhv->xhv_max) { + entry = (HvARRAY(stash))[riter]; + + /* Iterate through the entries in this list */ + for(; entry; entry = HeNEXT(entry)) { + const char* key; + I32 len; + + /* If this entry is not a glob, ignore it. + Try the next. */ + if (!isGV(HeVAL(entry))) continue; + + key = hv_iterkey(entry, &len); + if(len > 1 && key[len-2] == ':' && key[len-1] == ':') { + HV *substash; + + /* If this entry was seen when we iterated through the + oldstash, skip it. */ + if(seen && hv_exists(seen, key, len)) continue; + + /* We get here only if this stash has no corresponding + entry in the stash being replaced. */ + + substash = GvHV(HeVAL(entry)); + if(substash) { + SV *namesv; + const char *subname; + STRLEN subnamlen; + + /* Avoid checking main::main::main::... */ + if(substash == stash) continue; + + /* Add :: and the key (minus the trailing ::) + to newname. */ + namesv + = newSVpvn_flags(name, namlen, SVs_TEMP); + sv_catpvs(namesv, "::"); + sv_catpvn(namesv, key, len-2); + subname = SvPV_const(namesv, subnamlen); + mro_gather_and_rename( + stashes, seen_stashes, + substash, NULL, subname, subnamlen + ); + } + } + } + } } +} - if(items > 0) { - while (items--) { - linear_sv = *linear_svp++; - assert(linear_sv); - curstash = gv_stashsv(linear_sv, FALSE); - - if (!curstash || (HvMROMETA(curstash)->fake && !HvFILL(curstash))) { - if (ckWARN(WARN_SYNTAX)) - Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", - (void*)linear_sv, hvname); - continue; - } +/* +=for apidoc mro_method_changed_in - assert(curstash); +Invalidates method caching on any child classes +of the given stash, so that they might notice +the changes in this one. - gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); - if (!gvp) continue; +Ideally, all instances of C in +perl source outside of C should be +replaced by calls to this. - candidate = *gvp; - assert(candidate); +Perl automatically handles most of the common +ways a method might be redefined. However, there +are a few ways you could change a method in a stash +without the cache code noticing, in which case you +need to call this method afterwards: - if (SvTYPE(candidate) != SVt_PVGV) - gv_init(candidate, curstash, subname, subname_len, TRUE); - if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { - SvREFCNT_inc_simple_void_NN((SV*)cand_cv); - hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0); - return (SV*)cand_cv; - } - } - } +1) Directly manipulating the stash HV entries from +XS code. - hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); - if(throw_nomethod) - Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); - return &PL_sv_undef; -} - -#include "XSUB.h" +2) Assigning a reference to a readonly scalar +constant into a stash entry in order to create +a constant subroutine (like constant.pm +does). -XS(XS_mro_get_linear_isa); -XS(XS_mro_set_mro); -XS(XS_mro_get_mro); -XS(XS_mro_get_isarev); -XS(XS_mro_is_universal); -XS(XS_mro_get_global_sub_generation); -XS(XS_mro_invalidate_all_method_caches); -XS(XS_mro_get_sub_generation); -XS(XS_mro_method_changed_in); -XS(XS_next_can); -XS(XS_next_method); -XS(XS_maybe_next_method); +This same method is available from pure perl +via, C. +=cut +*/ void -Perl_boot_core_mro(pTHX) +Perl_mro_method_changed_in(pTHX_ HV *stash) { - dVAR; - static const char file[] = __FILE__; + const char * const stashname = HvENAME_get(stash); + const STRLEN stashname_len = HvENAMELEN_get(stash); - newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$"); - newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$"); - newXSproto("mro::get_mro", XS_mro_get_mro, file, "$"); - newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$"); - newXSproto("mro::is_universal", XS_mro_is_universal, file, "$"); - newXSproto("mro::get_global_sub_generation", XS_mro_get_global_sub_generation, file, ""); - newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_all_method_caches, file, ""); - newXSproto("mro::get_sub_generation", XS_mro_get_sub_generation, file, "$"); - newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); - newXS("next::can", XS_next_can, file); - newXS("next::method", XS_next_method, file); - newXS("maybe::next::method", XS_maybe_next_method, file); -} - -XS(XS_mro_get_linear_isa) { - dVAR; - dXSARGS; - AV* RETVAL; - HV* class_stash; - SV* classname; + SV ** const svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); + HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL; - PERL_UNUSED_ARG(cv); + PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; - if(items < 1 || items > 2) - Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])"); + if(!stashname) + Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); - classname = ST(0); - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); + /* Inc the package generation, since a local method changed */ + HvMROMETA(stash)->pkg_gen++; - if(items > 1) { - char* which = SvPV_nolen(ST(1)); - if(strEQ(which, "dfs")) - RETVAL = mro_get_linear_isa_dfs(class_stash, 0); - else if(strEQ(which, "c3")) - RETVAL = mro_get_linear_isa_c3(class_stash, 0); - else - Perl_croak(aTHX_ "Invalid mro name: '%s'", which); - } - else { - RETVAL = mro_get_linear_isa(class_stash); + /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, + invalidate all method caches globally */ + if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) + || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { + PL_sub_generation++; + return; } - ST(0) = newRV_inc((SV*)RETVAL); - sv_2mortal(ST(0)); - XSRETURN(1); + /* else, invalidate the method caches of all child classes, + but not itself */ + if(isarev) { + HE* iter; + + hv_iterinit(isarev); + while((iter = hv_iternext(isarev))) { + I32 len; + const char* const revkey = hv_iterkey(iter, &len); + HV* const revstash = gv_stashpvn(revkey, len, 0); + struct mro_meta* mrometa; + + if(!revstash) continue; + mrometa = HvMROMETA(revstash); + mrometa->cache_gen++; + if(mrometa->mro_nextmethod) + hv_clear(mrometa->mro_nextmethod); + } + } } -XS(XS_mro_set_mro) +void +Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name) { - dVAR; - dXSARGS; - SV* classname; - char* whichstr; - mro_alg which; - HV* class_stash; - struct mro_meta* meta; - - PERL_UNUSED_ARG(cv); + const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name); + + PERL_ARGS_ASSERT_MRO_SET_MRO; - if (items != 2) - Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)"); - - classname = ST(0); - whichstr = SvPV_nolen(ST(1)); - class_stash = gv_stashsv(classname, GV_ADD); - if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); - meta = HvMROMETA(class_stash); - - if(strEQ(whichstr, "dfs")) - which = MRO_DFS; - else if(strEQ(whichstr, "c3")) - which = MRO_C3; - else - Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); + if (!which) + Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name); if(meta->mro_which != which) { - meta->mro_which = which; + if (meta->mro_linear_current && !meta->mro_linear_all) { + /* If we were storing something directly, put it in the hash before + we lose it. */ + Perl_mro_set_private_data(aTHX_ meta, meta->mro_which, + MUTABLE_SV(meta->mro_linear_current)); + } + meta->mro_which = which; + /* Scrub our cached pointer to the private data. */ + meta->mro_linear_current = NULL; /* Only affects local method cache, not even child classes */ - meta->sub_generation++; + meta->cache_gen++; if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); } - - XSRETURN_EMPTY; } +#include "XSUB.h" -XS(XS_mro_get_mro) -{ - dVAR; - dXSARGS; - SV* classname; - HV* class_stash; - struct mro_meta* meta; - - PERL_UNUSED_ARG(cv); - - if (items != 1) - Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); - - classname = ST(0); - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - meta = HvMROMETA(class_stash); - - if(meta->mro_which == MRO_DFS) - ST(0) = sv_2mortal(newSVpvn("dfs", 3)); - else - ST(0) = sv_2mortal(newSVpvn("c3", 2)); - - XSRETURN(1); -} - -XS(XS_mro_get_isarev) -{ - dVAR; - dXSARGS; - SV* classname; - HV* class_stash; - HV* isarev; - - PERL_UNUSED_ARG(cv); - - if (items != 1) - Perl_croak(aTHX_ "Usage: mro::get_isarev(classname)"); - - classname = ST(0); - - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - - SP -= items; - - if((isarev = HvMROMETA(class_stash)->mro_isarev)) { - HE* iter; - hv_iterinit(isarev); - while((iter = hv_iternext(isarev))) - XPUSHs(hv_iterkeysv(iter)); - } - - PUTBACK; - return; -} - -XS(XS_mro_is_universal) -{ - dVAR; - dXSARGS; - SV* classname; - HV* class_stash; - - PERL_UNUSED_ARG(cv); - - if (items != 1) - Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); - - classname = ST(0); - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - - if (HvMROMETA(class_stash)->is_universal) - XSRETURN_YES; - else - XSRETURN_NO; -} - -XS(XS_mro_get_global_sub_generation) -{ - dVAR; - dXSARGS; - - PERL_UNUSED_ARG(cv); - - if (items != 0) - Perl_croak(aTHX_ "Usage: mro::get_global_sub_generation()"); - - ST(0) = sv_2mortal(newSViv(PL_sub_generation)); - XSRETURN(1); -} - -XS(XS_mro_invalidate_all_method_caches) -{ - dVAR; - dXSARGS; - - PERL_UNUSED_ARG(cv); - - if (items != 0) - Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()"); - - PL_sub_generation++; - - XSRETURN_EMPTY; -} +XS(XS_mro_method_changed_in); -XS(XS_mro_get_sub_generation) +void +Perl_boot_core_mro(pTHX) { dVAR; - dXSARGS; - SV* classname; - HV* class_stash; - - PERL_UNUSED_ARG(cv); - - if(items != 1) - Perl_croak(aTHX_ "Usage: mro::get_sub_generation(classname)"); + static const char file[] = __FILE__; - classname = ST(0); - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); + Perl_mro_register(aTHX_ &dfs_alg); - ST(0) = sv_2mortal(newSViv(HvMROMETA(class_stash)->sub_generation)); - XSRETURN(1); + newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); } XS(XS_mro_method_changed_in) @@ -931,10 +1189,8 @@ XS(XS_mro_method_changed_in) SV* classname; HV* class_stash; - PERL_UNUSED_ARG(cv); - if(items != 1) - Perl_croak(aTHX_ "Usage: mro::method_changed_in(classname)"); + croak_xs_usage(cv, "classname"); classname = ST(0); @@ -946,57 +1202,6 @@ XS(XS_mro_method_changed_in) XSRETURN_EMPTY; } -XS(XS_next_can) -{ - dVAR; - dXSARGS; - SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 0); - - PERL_UNUSED_ARG(cv); - PERL_UNUSED_VAR(items); - - if(methcv == &PL_sv_undef) { - ST(0) = &PL_sv_undef; - } - else { - ST(0) = sv_2mortal(newRV_inc(methcv)); - } - - XSRETURN(1); -} - -XS(XS_next_method) -{ - dMARK; - dAX; - SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 1); - - PERL_UNUSED_ARG(cv); - - PL_markstack_ptr++; - call_sv(methcv, GIMME_V); -} - -XS(XS_maybe_next_method) -{ - dMARK; - dAX; - SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 0); - - PERL_UNUSED_ARG(cv); - - if(methcv == &PL_sv_undef) { - ST(0) = &PL_sv_undef; - XSRETURN(1); - } - - PL_markstack_ptr++; - call_sv(methcv, GIMME_V); -} - /* * Local variables: * c-indentation-style: bsd