X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FClass-C3-XS.git;a=blobdiff_plain;f=XS.xs;h=19340c2bd99aeb475046ea2234e41d025ea53067;hp=f3730e6327873dfe13cb50ee6ddc9483415614c7;hb=ff94166e91692aaaab9cc8b493cd753d88e56b2c;hpb=79782a491f16887c4f1e26d8706cf574c9804a95

diff --git a/XS.xs b/XS.xs
index f3730e6..19340c2 100644
--- a/XS.xs
+++ b/XS.xs
@@ -3,6 +3,53 @@
 #include "perl.h"
 #include "XSUB.h"
 
+/* *********** ppport stuff */
+
+#ifndef PERL_UNUSED_VAR
+#  define PERL_UNUSED_VAR(x) ((void)x)
+#endif
+
+#if defined(PERL_GCC_PEDANTIC)
+#  ifndef PERL_GCC_BRACE_GROUPS_FORBIDDEN
+#    define PERL_GCC_BRACE_GROUPS_FORBIDDEN
+#  endif
+#endif
+
+#if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN) && !defined(__cplusplus)
+#  ifndef PERL_USE_GCC_BRACE_GROUPS
+#    define PERL_USE_GCC_BRACE_GROUPS
+#  endif
+#endif
+
+#ifndef SvREFCNT_inc
+#  ifdef PERL_USE_GCC_BRACE_GROUPS
+#    define SvREFCNT_inc(sv)		\
+      ({				\
+          SV * const _sv = (SV*)(sv);	\
+          if (_sv)			\
+               (SvREFCNT(_sv))++;	\
+          _sv;				\
+      })
+#  else
+#    define SvREFCNT_inc(sv)	\
+          ((PL_Sv=(SV*)(sv)) ? (++(SvREFCNT(PL_Sv)),PL_Sv) : NULL)
+#  endif
+#endif
+
+#ifndef dAX
+#  define dAX                            I32 ax = MARK - PL_stack_base + 1
+#endif
+
+#ifndef dVAR
+#  define dVAR                           dNOOP
+#endif
+
+#ifndef packWARN
+#  define packWARN(a)                    (a)
+#endif
+
+/* *********** end ppport.h stuff */
+
 /* Most of this code is backported from the bleadperl patch's
    mro.c, and then modified to work with Class::C3's
    internals.
@@ -17,6 +64,7 @@ __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
     AV* isa;
     const char* stashname;
     STRLEN stashname_len;
+    I32 made_mortal_cache = 0;
 
     assert(stash);
 
@@ -32,6 +80,7 @@ __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
 
     if(!cache) {
         cache = (HV*)sv_2mortal((SV*)newHV());
+        made_mortal_cache = 1;
     }
     else {
         SV** cache_entry = hv_fetch(cache, stashname, stashname_len, 0);
@@ -41,101 +90,171 @@ __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
 
     /* not in cache, make a new one */
 
-    retval = newAV();
-    av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */
-
     gvp = (GV**)hv_fetch(stash, "ISA", 3, FALSE);
     isa = (gvp && (gv = *gvp) && gv != (GV*)&PL_sv_undef) ? 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());
+        HV* const tails = (HV*)sv_2mortal((SV*)newHV());
+        AV* const seqs = (AV*)sv_2mortal((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, (SV*)isa_lin);
             }
             else {
-                isa_lin = (AV*)sv_2mortal((SV*)__mro_linear_isa_c3(aTHX_ isa_item_stash, cache, level + 1)); /* recursion */
+                /* recursion */
+                AV* const isa_lin = __mro_linear_isa_c3(aTHX_ isa_item_stash, cache, level + 1);
+                av_push(seqs, (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((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) */
+        Newz(0xdead, 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 = (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);
+                    SV* const seqitem = *seq_ptr++;
+                    HE* const 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 val = HeVAL(he);
                         sv_inc(val);
                     }
                 }
             }
         }
 
+        /* Initialize retval to build the return value in */
+        retval = newAV();
+        av_push(retval, newSVpvn(stashname, stashname_len)); /* 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 = (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)) {
-                    sv_2mortal(av_shift(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 '%s'", stashname, SvPV_nolen(cand));
             }
         }
     }
+    else { /* @ISA was undefined or empty */
+        /* build a retval containing only ourselves */
+        retval = newAV();
+        av_push(retval, newSVpvn(stashname, stashname_len));
+    }
 
+    /* we don't want anyone modifying the cache entry but us,
+       and we do so by replacing it completely */
     SvREADONLY_on(retval);
-    hv_store(cache, stashname, stashname_len, (SV*)retval, 0);
-    return (AV*)SvREFCNT_inc(retval);
+
+    if(!made_mortal_cache) {
+        SvREFCNT_inc(retval);
+        hv_store(cache, stashname, stashname_len, (SV*)retval, 0);
+    }
+
+    return retval;
 }
 
 STATIC I32
@@ -147,9 +266,13 @@ __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) {
     return i;
 }
 
-STATIC SV*
-__nextcan(pTHX_ SV* self, I32 throw_nomethod)
+XS(XS_Class_C3_XS_nextcan);
+XS(XS_Class_C3_XS_nextcan)
 {
+    dVAR; dXSARGS;
+
+    SV* self = ST(0);
+    const I32 throw_nomethod = SvIVX(ST(1));
     register I32 cxix;
     register const PERL_CONTEXT *ccstack = cxstack;
     const PERL_SI *top_si = PL_curstackinfo;
@@ -165,16 +288,17 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
     GV** gvp;
     AV* linear_av;
     SV** linear_svp;
-    SV* linear_sv;
     HV* cstash;
     GV* candidate = NULL;
     CV* cand_cv = NULL;
     const char *hvname;
-    I32 items;
+    I32 entries;
     HV* nmcache;
     HE* cache_entry;
     SV* cachekey;
 
+    SP -= items;
+
     if(sv_isobject(self))
         selfstash = SvSTASH(SvRV(self));
     else
@@ -187,6 +311,7 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
         Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup");
 
     cxix = __dopoptosub_at(cxstack, cxstack_ix);
+    cxix = __dopoptosub_at(ccstack, cxix - 1); /* skip next::method, etc */
 
     /* This block finds the contextually-enclosing fully-qualified subname,
        much like looking at (caller($i))[3] until you find a real sub that
@@ -258,9 +383,10 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
         if(val == &PL_sv_undef) {
             if(throw_nomethod)
                 Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname);
-            return &PL_sv_undef;
+            XSRETURN_EMPTY;
         }
-        return SvREFCNT_inc(val);
+        XPUSHs(sv_2mortal(newRV_inc(val)));
+        XSRETURN(1);
     }
 
     /* beyond here is just for cache misses, so perf isn't as critical */
@@ -271,21 +397,21 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
     linear_av = __mro_linear_isa_c3(aTHX_ selfstash, NULL, 0);
 
     linear_svp = AvARRAY(linear_av);
-    items = AvFILLp(linear_av) + 1;
+    entries = AvFILLp(linear_av) + 1;
 
-    while (items--) {
-        linear_sv = *linear_svp++;
+    while (entries--) {
+        SV* const linear_sv = *linear_svp++;
         assert(linear_sv);
         if(sv_eq(linear_sv, stashname))
             break;
     }
 
-    if(items > 0) {
+    if(entries > 0) {
         SV* sub_sv = sv_2mortal(newSVpv(subname, subname_len));
         HV* cc3_mro = get_hv("Class::C3::MRO", 0);
 
-        while (items--) {
-            linear_sv = *linear_svp++;
+        while (entries--) {
+            SV* const linear_sv = *linear_svp++;
             assert(linear_sv);
 
             if(cc3_mro) {
@@ -330,7 +456,8 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
                 SvREFCNT_dec(linear_av);
                 SvREFCNT_inc((SV*)cand_cv);
                 hv_store_ent(nmcache, newSVsv(cachekey), (SV*)cand_cv, 0);
-                return (SV*)cand_cv;
+                XPUSHs(sv_2mortal(newRV_inc((SV*)cand_cv)));
+                XSRETURN(1);
             }
         }
     }
@@ -339,17 +466,13 @@ __nextcan(pTHX_ SV* self, I32 throw_nomethod)
     hv_store_ent(nmcache, newSVsv(cachekey), &PL_sv_undef, 0);
     if(throw_nomethod)
         Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname);
-    return &PL_sv_undef;
+    XSRETURN_EMPTY;
 }
 
 XS(XS_Class_C3_XS_calculateMRO);
 XS(XS_Class_C3_XS_calculateMRO)
 {
-#ifdef dVAR
     dVAR; dXSARGS;
-#else
-    dXSARGS;
-#endif
 
     SV* classname;
     HV* class_stash;
@@ -387,14 +510,21 @@ XS(XS_Class_C3_XS_calculateMRO)
     return;
 }
 
+XS(XS_Class_C3_XS_plsubgen);
+XS(XS_Class_C3_XS_plsubgen)
+{
+    dVAR; dXSARGS;
+
+    SP -= items;
+    XPUSHs(sv_2mortal(newSViv(PL_sub_generation)));
+    PUTBACK;
+    return;
+}
+
 XS(XS_Class_C3_XS_calc_mdt);
 XS(XS_Class_C3_XS_calc_mdt)
 {
-#ifdef dVAR
     dVAR; dXSARGS;
-#else
-    dXSARGS;
-#endif
 
     SV* classname;
     HV* cache;
@@ -423,10 +553,9 @@ XS(XS_Class_C3_XS_calc_mdt)
     class_mro = __mro_linear_isa_c3(aTHX_ class_stash, cache, 0);
 
     our_c3mro = newHV();
-    hv_store(our_c3mro, "MRO", 3, (SV*)newRV_inc((SV*)class_mro), 0);
+    hv_store(our_c3mro, "MRO", 3, (SV*)newRV_noinc((SV*)class_mro), 0);
 
     hv = get_hv("Class::C3::MRO", 1);
-    hv_delete_ent(hv, classname, G_DISCARD, 0);
     hv_store_ent(hv, classname, (SV*)newRV_noinc((SV*)our_c3mro), 0);
 
     methods = newHV();
@@ -482,65 +611,11 @@ XS(XS_Class_C3_XS_calc_mdt)
     XSRETURN_EMPTY;
 }
 
-XS(XS_next_can);
-XS(XS_next_can)
-{
-#ifdef dVAR
-    dVAR; dXSARGS;
-#else
-    dXSARGS;
-#endif
-
-    SV* self = ST(0);
-    SV* methcv = __nextcan(aTHX_ self, 0);
-
-    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);
-XS(XS_next_method)
-{
-    dMARK;
-    dAX;
-    SV* self = ST(0);
-    SV* methcv = __nextcan(aTHX_ self, 1);
-
-    PL_markstack_ptr++;
-    call_sv(methcv, GIMME_V);
-}
-
-XS(XS_maybe_next_method);
-XS(XS_maybe_next_method)
-{
-    dMARK;
-    dAX;
-    SV* self = ST(0);
-    SV* methcv = __nextcan(aTHX_ self, 0);
-
-    if(methcv == &PL_sv_undef) {
-        ST(0) = &PL_sv_undef;
-        XSRETURN(1);
-    }
-
-    PL_markstack_ptr++;
-    call_sv(methcv, GIMME_V);
-}
-
 MODULE = Class::C3::XS	PACKAGE = Class::C3::XS
 
 BOOT:
     newXS("Class::C3::XS::calculateMRO", XS_Class_C3_XS_calculateMRO, __FILE__);
+    newXS("Class::C3::XS::_plsubgen", XS_Class_C3_XS_plsubgen, __FILE__);
     newXS("Class::C3::XS::_calculate_method_dispatch_table", XS_Class_C3_XS_calc_mdt, __FILE__);
-    newXS("next::can", XS_next_can, __FILE__);
-    newXS("next::method", XS_next_method, __FILE__);
-    newXS("maybe::next::method", XS_maybe_next_method, __FILE__);
+    newXS("Class::C3::XS::_nextcan", XS_Class_C3_XS_nextcan, __FILE__);