X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=mro.c;h=23070d990d6f02e4c2b5af10b1cb60d8df2b3bb6;hb=fa60396f123333e92849ecaecffb9252458d6678;hp=b6c4db8ea55b7c788f76f103d843143f5c06de7d;hpb=b0c482e323c9b6fa5590fdfb97e98a5b7645a046;p=p5sagit%2Fp5-mst-13.2.git diff --git a/mro.c b/mro.c index b6c4db8..23070d9 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. @@ -8,6 +9,13 @@ */ /* + * '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"] + */ + +/* =head1 MRO Functions These functions are related to the method resolution order of perl classes @@ -16,29 +24,103 @@ These functions are related to the method resolution order of perl classes */ #include "EXTERN.h" +#define PERL_IN_MRO_C #include "perl.h" +struct mro_alg { + AV *(*resolve)(pTHX_ HV* stash, U32 level); + const char *name; + U16 length; + U16 kflags; /* For the hash API - set HVhek_UTF8 if name is UTF-8 */ + U32 hash; /* or 0 */ +}; + +/* First one is the default */ +static struct mro_alg mros[] = { + {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0}, + {S_mro_get_linear_isa_c3, "c3", 2, 0, 0} +}; + +#define NUMBER_OF_MROS (sizeof(mros)/sizeof(struct mro_alg)) + +#define dfs_alg (&mros[0]) +#define c3_alg (&mros[1]) + +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 = Perl_hv_common(aTHX_ MUTABLE_HV(smeta->mro_linear_dfs), 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_c3 = MUTABLE_AV(*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 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_c3 = MUTABLE_AV(data); + + if (!smeta->mro_linear_dfs) { + HV *const hv = newHV(); + HvMAX(hv) = 0; /* Start with 1 bucket. It's unlikely we'll need more. + */ + smeta->mro_linear_dfs = MUTABLE_AV(hv); + } + + if (!Perl_hv_common(aTHX_ MUTABLE_HV(smeta->mro_linear_dfs), 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; +} + +static const struct mro_alg * +S_get_mro_from_name(pTHX_ const char *const name) { + const struct mro_alg *algo = mros; + const struct mro_alg *const end = mros + NUMBER_OF_MROS; + while (algo < end) { + if(strEQ(name, algo->name)) + return algo; + ++algo; + } + return NULL; +} + 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 = mros; return newmeta; } @@ -49,36 +131,64 @@ 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_dfs) + newmeta->mro_linear_dfs + = MUTABLE_AV(SvREFCNT_inc(sv_dup((const SV *)newmeta->mro_linear_dfs, param))); + newmeta->mro_linear_c3 = NULL; + if (newmeta->mro_nextmethod) + newmeta->mro_nextmethod + = MUTABLE_HV(SvREFCNT_inc(sv_dup((const SV *)newmeta->mro_nextmethod, param))); + if (newmeta->isa) + newmeta->isa + = MUTABLE_HV(SvREFCNT_inc(sv_dup((const SV *)newmeta->isa, param))); return newmeta; } #endif /* USE_ITHREADS */ +HV * +Perl_get_isa_hash(pTHX_ HV *const stash) +{ + dVAR; + struct mro_meta *const meta = HvMROMETA(stash); + + PERL_ARGS_ASSERT_GET_ISA_HASH; + + if (!meta->isa) { + AV *const isa = mro_get_linear_isa(stash); + 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 *const 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 meta->isa; +} + /* =for apidoc mro_get_linear_isa_dfs @@ -87,80 +197,148 @@ 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; - 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 = 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(Perl_mro_get_private_data(aTHX_ 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. */ + + stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); + + 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; + } + 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); + } } } } + (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); + (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); + + SvREFCNT_inc_simple_void_NN(stored); + SvTEMP_off(stored); + SvREADONLY_on(stored); + + meta->isa = stored; + + /* 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_dfs = retval; - return retval; + + return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, dfs_alg, + MUTABLE_SV(retval))); } /* @@ -171,142 +349,214 @@ 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_c3(pTHX_ HV* stash, I32 level) +static AV* +S_mro_get_linear_isa_c3(pTHX_ HV* stash, U32 level) { AV* retval; GV** gvp; GV* gv; AV* isa; - const char* stashname; - STRLEN stashname_len; + const HEK* stashhek; struct mro_meta* meta; - assert(stash); + PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_C3; assert(HvAUX(stash)); - stashname = HvNAME_get(stash); - stashname_len = HvNAMELEN_get(stash); - if (!stashname) - Perl_croak(aTHX_ - "Can't linearize anonymous symbol table"); + stashhek = 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_c3)) { - /* return cache if valid */ + + /* return cache if valid */ + if((retval = MUTABLE_AV(Perl_mro_get_private_data(aTHX_ meta, c3_alg)))) { 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; + /* For a better idea how the rest of this works, see the much clearer + pure perl version in Algorithm::C3 0.01: + http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm + (later versions go about it differently than this code for speed reasons) + */ + 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()); + HV* const tails = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); + AV *const seqs = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); + I32* heads; + + /* This builds @seqs, which is an array of arrays. + The members of @seqs are the MROs of + the members of @ISA, followed by @ISA itself. + */ 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); + SV* const isa_item = *isa_ptr++; + HV* const isa_item_stash = gv_stashsv(isa_item, 0); if(!isa_item_stash) { - isa_lin = newAV(); + /* if no stash, make a temporary fake MRO + containing just itself */ + AV* const isa_lin = newAV(); av_push(isa_lin, newSVsv(isa_item)); + av_push(seqs, MUTABLE_SV(isa_lin)); } else { - isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */ + /* recursion */ + AV* const isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); + av_push(seqs, SvREFCNT_inc_simple_NN(MUTABLE_SV(isa_lin))); } - av_push(seqs, (SV*)av_make(AvFILLp(isa_lin)+1, AvARRAY(isa_lin))); } - av_push(seqs, (SV*)av_make(AvFILLp(isa)+1, AvARRAY(isa))); - + av_push(seqs, SvREFCNT_inc_simple_NN(MUTABLE_SV(isa))); + + /* This builds "heads", which as an array of integer array + indices, one per seq, which point at the virtual "head" + of the seq (initially zero) */ + Newxz(heads, AvFILLp(seqs)+1, I32); + + /* This builds %tails, which has one key for every class + mentioned in the tail of any sequence in @seqs (tail meaning + everything after the first class, the "head"). The value + is how many times this key appears in the tails of @seqs. + */ seqs_ptr = AvARRAY(seqs); seqs_items = AvFILLp(seqs) + 1; while(seqs_items--) { - AV* seq = (AV*)*seqs_ptr++; + AV *const seq = MUTABLE_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* const seqitem = *seq_ptr++; + /* LVALUE fetch will create a new undefined SV if necessary + */ + HE* const he = hv_fetch_ent(tails, seqitem, 1, 0); + if(he) { + SV* const val = HeVAL(he); + /* This will increment undef to 1, which is what we + want for a newly created entry. */ sv_inc(val); } } } } + /* Initialize retval to build the return value in */ + retval = newAV(); + av_push(retval, newSVhek(stashhek)); /* us first */ + + /* This loop won't terminate until we either finish building + the MRO, or get an exception. */ 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--) { + int s; + + /* "foreach $seq (@seqs)" */ + SV** const avptr = AvARRAY(seqs); + for(s = 0; s <= AvFILLp(seqs); s++) { SV** svp; - seq = (AV*)*avptr++; - if(AvFILLp(seq) < 0) continue; - svp = av_fetch(seq, 0, 0); - seqhead = *svp; + AV * const seq = MUTABLE_AV(avptr[s]); + SV* seqhead; + if(!seq) continue; /* skip empty seqs */ + svp = av_fetch(seq, heads[s], 0); + seqhead = *svp; /* seqhead = head of this seq */ if(!winner) { + HE* tail_entry; + SV* val; + /* if we haven't found a winner for this round yet, + and this seqhead is not in tails (or the count + for it in tails has dropped to zero), then this + seqhead is our new winner, and is added to the + final MRO immediately */ cand = seqhead; if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) && (val = HeVAL(tail_entry)) - && (SvIVx(val) > 0)) + && (SvIVX(val) > 0)) continue; winner = newSVsv(cand); av_push(retval, winner); + /* note however that even when we find a winner, + we continue looping over @seqs to do housekeeping */ } 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); + /* Once we have a winner (including the iteration + where we first found him), inc the head ptr + for any seq which had the winner as a head, + NULL out any seq which is now empty, + and adjust tails for consistency */ + + const int new_head = ++heads[s]; + if(new_head > AvFILLp(seq)) { + SvREFCNT_dec(avptr[s]); + avptr[s] = NULL; + } + else { + HE* tail_entry; + SV* val; + /* Because we know this new seqhead used to be + a tail, we can assume it is in tails and has + a positive value, which we need to dec */ + svp = av_fetch(seq, new_head, 0); + seqhead = *svp; + tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); + val = HeVAL(tail_entry); + sv_dec(val); + } } } - if(!cand) break; + + /* if we found no candidates, we are done building the MRO. + !cand means no seqs have any entries left to check */ + if(!cand) { + Safefree(heads); + break; + } + + /* If we had candidates, but nobody won, then the @ISA + hierarchy is not C3-incompatible */ if(!winner) { + /* we have to do some cleanup before we croak */ + SvREFCNT_dec(retval); + Safefree(heads); + Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " - "merging failed on parent '%"SVf"'", stashname, SVfARG(cand)); + "merging failed on parent '%"SVf"'", HEK_KEY(stashhek), SVfARG(cand)); } } } + else { /* @ISA was undefined or empty */ + /* build a retval containing only ourselves */ + retval = newAV(); + av_push(retval, newSVhek(stashhek)); + } + /* 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 MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, c3_alg, + MUTABLE_SV(retval))); return retval; } @@ -319,29 +569,33 @@ 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)); + + 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!"); - } + return meta->mro_which->resolve(aTHX_ stash, 0); } /* =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. @@ -356,90 +610,109 @@ 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; - stashname = HvNAME_get(stash); + const char * const stashname = HvNAME_get(stash); + const STRLEN stashname_len = HvNAMELEN_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"); /* 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); + SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_dfs)); meta->mro_linear_dfs = NULL; meta->mro_linear_c3 = NULL; + if (meta->isa) { + SvREFCNT_dec(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)) { + if(isarev) { hv_iterinit(isarev); 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); + 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); + SvREFCNT_dec(MUTABLE_SV(revmeta->mro_linear_dfs)); revmeta->mro_linear_dfs = NULL; revmeta->mro_linear_c3 = NULL; - if(!meta->is_universal) - revmeta->sub_generation++; + if(!is_universal) + revmeta->cache_gen++; if(revmeta->mro_nextmethod) hv_clear(revmeta->mro_nextmethod); } } - /* we're starting at the 2nd element, skipping ourselves here */ + /* Now iterate our MRO (parents), and do a few things: + 1) instantiate with the "fake" flag if they don't exist + 2) flag them as universal if we are universal + 3) Add 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); - mrometa = HvMROMETA(mrostash); - mroisarev = mrometa->mro_isarev; + /* 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. */ - /* is_universal is viral */ - if(meta->is_universal) - mrometa->is_universal = 1; + mroisarev = MUTABLE_HV(HeVAL(he)); - if(!mroisarev) - mroisarev = mrometa->mro_isarev = newHV(); + SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); - if(!hv_exists(mroisarev, stashname, strlen(stashname))) - hv_store(mroisarev, stashname, strlen(stashname), &PL_sv_yes, 0); + /* 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(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); + I32 revkeylen; + char* const revkey = hv_iterkey(iter, &revkeylen); + (void)hv_store(mroisarev, revkey, revkeylen, &PL_sv_yes, 0); } } } @@ -448,51 +721,73 @@ Perl_mro_isa_changed_in(pTHX_ HV* stash) /* =for apidoc mro_method_changed_in -Like C, but invalidates method -caching on any child classes of the given stash, so -that they might notice the changes in this one. +Invalidates method caching on any child classes +of the given stash, so that they might notice +the changes in this one. 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. +perl source outside of C should be +replaced by calls to this. + +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: -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. +1) Directly manipulating the stash HV entries from +XS code. -If you're doing such a thing from pure perl, use -C, which -just calls this. +2) Assigning a reference to a readonly scalar +constant into a stash entry in order to create +a constant subroutine (like constant.pm +does). + +This same method is available from pure perl +via, C. =cut */ void Perl_mro_method_changed_in(pTHX_ HV *stash) { - struct mro_meta* meta = HvMROMETA(stash); - HV* isarev; - HE* iter; + const char * const stashname = HvNAME_get(stash); + const STRLEN stashname_len = HvNAMELEN_get(stash); + + SV ** const svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); + HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL; + + PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; + + if(!stashname) + Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); + + /* Inc the package generation, since a local method changed */ + HvMROMETA(stash)->pkg_gen++; /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, invalidate all method caches globally */ - if(meta->is_universal) { + if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) + || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { PL_sub_generation++; return; } /* else, invalidate the method caches of all child classes, but not itself */ - if((isarev = meta->mro_isarev)) { + if(isarev) { + HE* iter; + 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++; + 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); } @@ -513,174 +808,6 @@ __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { return i; } -STATIC SV* -__nextcan(pTHX_ SV* self, I32 throw_nomethod) -{ - 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; - } - - /* If we made it to here, we found our context */ - - selfmeta = HvMROMETA(selfstash); - if(!(nmcache = selfmeta->mro_nextmethod)) { - nmcache = selfmeta->mro_nextmethod = newHV(); - } - - 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); - } - 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; - - while (items--) { - linear_sv = *linear_svp++; - assert(linear_sv); - if(sv_eq(linear_sv, stashname)) - break; - } - - 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; - } - - assert(curstash); - - gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); - if (!gvp) continue; - - candidate = *gvp; - assert(candidate); - - 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; - } - } - } - - 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" XS(XS_mro_get_linear_isa); @@ -688,13 +815,10 @@ 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_invalidate_method_caches); XS(XS_mro_method_changed_in); -XS(XS_next_can); -XS(XS_next_method); -XS(XS_maybe_next_method); +XS(XS_mro_get_pkg_gen); +XS(XS_mro_nextcan); void Perl_boot_core_mro(pTHX) @@ -707,13 +831,10 @@ Perl_boot_core_mro(pTHX) 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, "$"); + newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, ""); newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); - newXS("next::can", XS_next_can, file); - newXS("next::method", XS_next_method, file); - newXS("maybe::next::method", XS_maybe_next_method, file); + newXSproto("mro::get_pkg_gen", XS_mro_get_pkg_gen, file, "$"); + newXS("mro::_nextcan", XS_mro_nextcan, file); } XS(XS_mro_get_linear_isa) { @@ -723,29 +844,31 @@ XS(XS_mro_get_linear_isa) { HV* class_stash; SV* classname; - PERL_UNUSED_ARG(cv); - if(items < 1 || items > 2) - Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])"); + croak_xs_usage(cv, "classname [, type ]"); classname = ST(0); class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - 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); + if(!class_stash) { + /* No stash exists yet, give them just the classname */ + AV* isalin = newAV(); + av_push(isalin, newSVsv(classname)); + ST(0) = sv_2mortal(newRV_noinc(MUTABLE_SV(isalin))); + XSRETURN(1); + } + else if(items > 1) { + const char* const which = SvPV_nolen(ST(1)); + const struct mro_alg *const algo = S_get_mro_from_name(aTHX_ which); + if (!algo) + Perl_croak(aTHX_ "Invalid mro name: '%s'", which); + RETVAL = algo->resolve(aTHX_ class_stash, 0); } else { RETVAL = mro_get_linear_isa(class_stash); } - ST(0) = newRV_inc((SV*)RETVAL); + ST(0) = newRV_inc(MUTABLE_SV(RETVAL)); sv_2mortal(ST(0)); XSRETURN(1); } @@ -755,15 +878,13 @@ XS(XS_mro_set_mro) dVAR; dXSARGS; SV* classname; - char* whichstr; - mro_alg which; + const char* whichstr; + const struct mro_alg *which; HV* class_stash; struct mro_meta* meta; - PERL_UNUSED_ARG(cv); - if (items != 2) - Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)"); + croak_xs_usage(cv, "classname, type"); classname = ST(0); whichstr = SvPV_nolen(ST(1)); @@ -771,18 +892,17 @@ XS(XS_mro_set_mro) 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 + which = S_get_mro_from_name(aTHX_ whichstr); + if (!which) Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); if(meta->mro_which != which) { meta->mro_which = which; + /* Scrub our cached pointer to the private data. */ + meta->mro_linear_c3 = 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); } @@ -797,23 +917,16 @@ XS(XS_mro_get_mro) 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)"); + croak_xs_usage(cv, "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)); + ST(0) = sv_2mortal(newSVpv(class_stash + ? HvMROMETA(class_stash)->mro_which->name + : "dfs", 0)); XSRETURN(1); } @@ -822,27 +935,29 @@ XS(XS_mro_get_isarev) dVAR; dXSARGS; SV* classname; - HV* class_stash; + HE* he; HV* isarev; - - PERL_UNUSED_ARG(cv); + AV* ret_array; if (items != 1) - Perl_croak(aTHX_ "Usage: mro::get_isarev(classname)"); + croak_xs_usage(cv, "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 = hv_fetch_ent(PL_isarev, classname, 0, 0); + isarev = he ? MUTABLE_HV(HeVAL(he)) : NULL; + + ret_array = newAV(); + if(isarev) { HE* iter; hv_iterinit(isarev); while((iter = hv_iternext(isarev))) - XPUSHs(hv_iterkeysv(iter)); + av_push(ret_array, newSVsv(hv_iterkeysv(iter))); } + mXPUSHs(newRV_noinc(MUTABLE_SV(ret_array))); PUTBACK; return; @@ -853,142 +968,275 @@ XS(XS_mro_is_universal) dVAR; dXSARGS; SV* classname; - HV* class_stash; - - PERL_UNUSED_ARG(cv); + HV* isarev; + char* classname_pv; + STRLEN classname_len; + HE* he; if (items != 1) - Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); + croak_xs_usage(cv, "classname"); classname = ST(0); - class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - - HvMROMETA(class_stash)->is_universal - ? XSRETURN_YES - : XSRETURN_NO; -} - -XS(XS_mro_get_global_sub_generation) -{ - dVAR; - dXSARGS; - PERL_UNUSED_ARG(cv); + classname_pv = SvPV(classname,classname_len); - if (items != 0) - Perl_croak(aTHX_ "Usage: mro::get_global_sub_generation()"); + he = hv_fetch_ent(PL_isarev, classname, 0, 0); + isarev = he ? MUTABLE_HV(HeVAL(he)) : NULL; - ST(0) = sv_2mortal(newSViv(PL_sub_generation)); - XSRETURN(1); + if((classname_len == 9 && strEQ(classname_pv, "UNIVERSAL")) + || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) + XSRETURN_YES; + else + XSRETURN_NO; } -XS(XS_mro_invalidate_all_method_caches) +XS(XS_mro_invalidate_method_caches) { dVAR; dXSARGS; - PERL_UNUSED_ARG(cv); - if (items != 0) - Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()"); + croak_xs_usage(cv, ""); PL_sub_generation++; XSRETURN_EMPTY; } -XS(XS_mro_get_sub_generation) +XS(XS_mro_method_changed_in) { dVAR; dXSARGS; SV* classname; HV* class_stash; - PERL_UNUSED_ARG(cv); - if(items != 1) - Perl_croak(aTHX_ "Usage: mro::get_sub_generation(classname)"); - + croak_xs_usage(cv, "classname"); + classname = ST(0); + class_stash = gv_stashsv(classname, 0); if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - ST(0) = sv_2mortal(newSViv(HvMROMETA(class_stash)->sub_generation)); - XSRETURN(1); + mro_method_changed_in(class_stash); + + XSRETURN_EMPTY; } -XS(XS_mro_method_changed_in) +XS(XS_mro_get_pkg_gen) { dVAR; dXSARGS; 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); class_stash = gv_stashsv(classname, 0); - if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); - mro_method_changed_in(class_stash); + SP -= items; - XSRETURN_EMPTY; + mXPUSHi(class_stash ? HvMROMETA(class_stash)->pkg_gen : 0); + + PUTBACK; + return; } -XS(XS_next_can) +XS(XS_mro_nextcan) { dVAR; dXSARGS; SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 0); + const I32 throw_nomethod = SvIVX(ST(1)); + register I32 cxix = cxstack_ix; + register const PERL_CONTEXT *ccstack = cxstack; + const PERL_SI *top_si = PL_curstackinfo; + HV* selfstash; + SV *stashname; + const char *fq_subname; + const char *subname; + STRLEN stashname_len; + STRLEN subname_len; + SV* sv; + GV** gvp; + AV* linear_av; + SV** linear_svp; + const char *hvname; + I32 entries; + struct mro_meta* selfmeta; + HV* nmcache; + I32 i; PERL_UNUSED_ARG(cv); - PERL_UNUSED_VAR(items); - if(methcv == &PL_sv_undef) { - ST(0) = &PL_sv_undef; + SP -= items; + + if(sv_isobject(self)) + selfstash = SvSTASH(SvRV(self)); + else + selfstash = gv_stashsv(self, GV_ADD); + + assert(selfstash); + + hvname = HvNAME_get(selfstash); + if (!hvname) + Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); + + /* 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 (also skips over pureperl next::method, etc) */ + for(i = 0; i < 2; i++) { + cxix = __dopoptosub_at(ccstack, cxix); + for (;;) { + GV* cvgv; + STRLEN fq_subname_len; + + /* 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; + } + cxix--; } - else { - ST(0) = sv_2mortal(newRV_inc(methcv)); + + /* If we made it to here, we found our context */ + + /* Initialize the next::method cache for this stash + if necessary */ + selfmeta = HvMROMETA(selfstash); + if(!(nmcache = selfmeta->mro_nextmethod)) { + nmcache = selfmeta->mro_nextmethod = newHV(); + } + else { /* Use the cached coderef if it exists */ + HE* cache_entry = hv_fetch_ent(nmcache, sv, 0, 0); + if (cache_entry) { + SV* const val = HeVAL(cache_entry); + if(val == &PL_sv_undef) { + if(throw_nomethod) + Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); + XSRETURN_EMPTY; + } + mXPUSHs(newRV_inc(val)); + XSRETURN(1); + } } - XSRETURN(1); -} + /* beyond here is just for cache misses, so perf isn't as critical */ -XS(XS_next_method) -{ - dMARK; - dAX; - SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 1); + stashname_len = subname - fq_subname - 2; + stashname = newSVpvn_flags(fq_subname, stashname_len, SVs_TEMP); - PERL_UNUSED_ARG(cv); + linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ - PL_markstack_ptr++; - call_sv(methcv, GIMME_V); -} + linear_svp = AvARRAY(linear_av); + entries = AvFILLp(linear_av) + 1; -XS(XS_maybe_next_method) -{ - dMARK; - dAX; - SV* self = ST(0); - SV* methcv = __nextcan(aTHX_ self, 0); + /* Walk down our MRO, skipping everything up + to the contextually enclosing class */ + while (entries--) { + SV * const linear_sv = *linear_svp++; + assert(linear_sv); + if(sv_eq(linear_sv, stashname)) + break; + } - PERL_UNUSED_ARG(cv); + /* Now search the remainder of the MRO for the + same method name as the contextually enclosing + method */ + if(entries > 0) { + while (entries--) { + SV * const linear_sv = *linear_svp++; + HV* curstash; + GV* candidate; + CV* cand_cv; - if(methcv == &PL_sv_undef) { - ST(0) = &PL_sv_undef; - XSRETURN(1); + assert(linear_sv); + curstash = gv_stashsv(linear_sv, FALSE); + + if (!curstash) { + if (ckWARN(WARN_SYNTAX)) + Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", + (void*)linear_sv, hvname); + continue; + } + + assert(curstash); + + gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); + if (!gvp) continue; + + candidate = *gvp; + assert(candidate); + + if (SvTYPE(candidate) != SVt_PVGV) + gv_init(candidate, curstash, subname, subname_len, TRUE); + + /* Notably, we only look for real entries, not method cache + entries, because in C3 the method cache of a parent is not + valid for the child */ + if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { + SvREFCNT_inc_simple_void_NN(MUTABLE_SV(cand_cv)); + (void)hv_store_ent(nmcache, newSVsv(sv), MUTABLE_SV(cand_cv), 0); + mXPUSHs(newRV_inc(MUTABLE_SV(cand_cv))); + XSRETURN(1); + } + } } - PL_markstack_ptr++; - call_sv(methcv, GIMME_V); + (void)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); + XSRETURN_EMPTY; } /*