1 /* This file is part of the autovivification Perl module.
2 * See http://search.cpan.org/dist/autovivification/ */
4 #define PERL_NO_GET_CONTEXT
9 #define __PACKAGE__ "autovivification"
10 #define __PACKAGE_LEN__ (sizeof(__PACKAGE__)-1)
12 /* --- Compatibility wrappers ---------------------------------------------- */
14 #define A_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
16 #ifndef A_WORKAROUND_REQUIRE_PROPAGATION
17 # define A_WORKAROUND_REQUIRE_PROPAGATION !A_HAS_PERL(5, 10, 1)
20 /* --- Helpers ------------------------------------------------------------- */
22 #if A_WORKAROUND_REQUIRE_PROPAGATION
24 #define A_ENCODE_UV(B, U) \
26 while (len < sizeof(UV)) { \
27 (B)[len++] = (U) & 0xFF; \
31 #define A_DECODE_UV(U, B) \
34 (U) = ((U) << 8) | (B)[--len];
36 STATIC SV *a_tag(pTHX_ UV bits) {
37 #define a_tag(B) a_tag(aTHX_ (B))
41 unsigned char buf[sizeof(UV) * 2];
44 for (si = PL_curstackinfo; si; si = si->si_prev) {
47 for (cxix = si->si_cxix; cxix >= 0; --cxix) {
48 const PERL_CONTEXT *cx = si->si_cxstack + cxix;
50 if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE)
55 A_ENCODE_UV(buf, requires);
56 A_ENCODE_UV(buf + sizeof(UV), bits);
57 hint = newSVpvn(buf, sizeof buf);
63 STATIC UV a_detag(pTHX_ const SV *hint) {
64 #define a_detag(H) a_detag(aTHX_ (H))
66 UV requires = 0, requires_max = 0, bits = 0;
70 if (!(hint && SvOK(hint)))
74 A_DECODE_UV(requires_max, buf);
76 for (si = PL_curstackinfo; si; si = si->si_prev) {
79 for (cxix = si->si_cxix; cxix >= 0; --cxix) {
80 const PERL_CONTEXT *cx = si->si_cxstack + cxix;
82 if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE
83 && ++requires > requires_max)
88 A_DECODE_UV(bits, buf + sizeof(UV));
93 #else /* A_WORKAROUND_REQUIRE_PROPAGATION */
95 #define a_tag(B) newSVuv(B)
96 #define a_detag(H) (((H) && SvOK(H)) ? SvUVX(H) : 0)
98 #endif /* !A_WORKAROUND_REQUIRE_PROPAGATION */
100 /* Used both for hints and op flags */
101 #define A_HINT_STRICT 1
102 #define A_HINT_WARN 2
103 #define A_HINT_FETCH 4
104 #define A_HINT_STORE 8
105 #define A_HINT_EXISTS 16
106 #define A_HINT_DELETE 32
107 #define A_HINT_NOTIFY (A_HINT_STRICT|A_HINT_WARN)
108 #define A_HINT_DO (A_HINT_FETCH|A_HINT_STORE|A_HINT_EXISTS|A_HINT_DELETE)
109 #define A_HINT_MASK (A_HINT_NOTIFY|A_HINT_DO)
111 /* Only used in op flags */
112 #define A_HINT_ROOT 64
113 #define A_HINT_DEREF 128
115 STATIC U32 a_hash = 0;
117 STATIC UV a_hint(pTHX) {
118 #define a_hint() a_hint(aTHX)
120 #if A_HAS_PERL(5, 9, 5)
121 hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
123 __PACKAGE__, __PACKAGE_LEN__,
127 SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, a_hash);
132 return a_detag(hint);
135 /* ... op => info map ...................................................... */
143 #define PTABLE_NAME ptable_map
144 #define PTABLE_VAL_FREE(V) PerlMemShared_free(V)
148 /* PerlMemShared_free() needs the [ap]PTBLMS_? default values */
149 #define ptable_map_store(T, K, V) ptable_map_store(aPTBLMS_ (T), (K), (V))
151 STATIC ptable *a_op_map = NULL;
154 STATIC perl_mutex a_op_map_mutex;
157 STATIC const a_op_info *a_map_fetch(const OP *o, a_op_info *oi) {
158 const a_op_info *val;
161 MUTEX_LOCK(&a_op_map_mutex);
164 val = ptable_fetch(a_op_map, o);
171 MUTEX_UNLOCK(&a_op_map_mutex);
177 STATIC const a_op_info *a_map_store_locked(pPTBLMS_ const OP *o, OP *(*old_pp)(pTHX), void *next, UV flags) {
178 #define a_map_store_locked(O, PP, N, F) a_map_store_locked(aPTBLMS_ (O), (PP), (N), (F))
181 if (!(oi = ptable_fetch(a_op_map, o))) {
182 oi = PerlMemShared_malloc(sizeof *oi);
183 ptable_map_store(a_op_map, o, oi);
193 STATIC void a_map_store(pPTBLMS_ const OP *o, OP *(*old_pp)(pTHX), void *next, UV flags) {
194 #define a_map_store(O, PP, N, F) a_map_store(aPTBLMS_ (O), (PP), (N), (F))
197 MUTEX_LOCK(&a_op_map_mutex);
200 a_map_store_locked(o, old_pp, next, flags);
203 MUTEX_UNLOCK(&a_op_map_mutex);
207 STATIC void a_map_delete(pTHX_ const OP *o) {
208 #define a_map_delete(O) a_map_delete(aTHX_ (O))
210 MUTEX_LOCK(&a_op_map_mutex);
213 ptable_map_store(a_op_map, o, NULL);
216 MUTEX_UNLOCK(&a_op_map_mutex);
220 STATIC const OP *a_map_descend(const OP *o) {
221 switch (PL_opargs[o->op_type] & OA_CLASS_MASK) {
225 case OA_BASEOP_OR_UNOP:
226 return cUNOPo->op_first;
229 return cLISTOPo->op_last;
235 STATIC void a_map_store_root(pPTBLMS_ const OP *root, OP *(*old_pp)(pTHX), UV flags) {
236 #define a_map_store_root(R, PP, F) a_map_store_root(aPTBLMS_ (R), (PP), (F))
237 const a_op_info *roi;
242 MUTEX_LOCK(&a_op_map_mutex);
245 roi = a_map_store_locked(o, old_pp, (OP *) root, flags | A_HINT_ROOT);
247 while (o->op_flags & OPf_KIDS) {
248 o = a_map_descend(o);
251 if ((oi = ptable_fetch(a_op_map, o))) {
252 oi->flags &= ~A_HINT_ROOT;
253 oi->next = (a_op_info *) roi;
259 MUTEX_UNLOCK(&a_op_map_mutex);
265 STATIC void a_map_update_flags_topdown(const OP *root, UV flags) {
270 MUTEX_LOCK(&a_op_map_mutex);
273 flags &= ~A_HINT_ROOT;
276 if ((oi = ptable_fetch(a_op_map, o)))
277 oi->flags = (oi->flags & A_HINT_ROOT) | flags;
278 if (!(o->op_flags & OPf_KIDS))
280 o = a_map_descend(o);
284 MUTEX_UNLOCK(&a_op_map_mutex);
290 #define a_map_cancel(R) a_map_update_flags_topdown((R), 0)
292 STATIC void a_map_update_flags_bottomup(const OP *o, UV flags, UV rflags) {
296 MUTEX_LOCK(&a_op_map_mutex);
299 flags &= ~A_HINT_ROOT;
300 rflags |= A_HINT_ROOT;
302 oi = ptable_fetch(a_op_map, o);
303 while (!(oi->flags & A_HINT_ROOT)) {
310 MUTEX_UNLOCK(&a_op_map_mutex);
316 /* ... Decide whether this expression should be autovivified or not ........ */
318 STATIC UV a_map_resolve(const OP *o, a_op_info *oi) {
319 UV flags = 0, rflags;
323 while (!(roi->flags & A_HINT_ROOT))
328 rflags = roi->flags & ~A_HINT_ROOT;
333 if (root->op_flags & OPf_MOD) {
334 if (rflags & A_HINT_STORE)
335 flags = (A_HINT_STORE|A_HINT_DEREF);
336 } else if (rflags & A_HINT_FETCH)
337 flags = (A_HINT_FETCH|A_HINT_DEREF);
341 a_map_update_flags_bottomup(o, 0, 0);
345 flags |= (rflags & A_HINT_NOTIFY);
346 a_map_update_flags_bottomup(o, flags, 0);
348 return oi->flags & A_HINT_ROOT ? 0 : flags;
351 /* ... Lightweight pp_defined() ............................................ */
353 STATIC bool a_defined(pTHX_ SV *sv) {
354 #define a_defined(S) a_defined(aTHX_ (S))
355 bool defined = FALSE;
357 switch (SvTYPE(sv)) {
359 if (AvMAX(sv) >= 0 || SvGMAGICAL(sv)
360 || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
364 if (HvARRAY(sv) || SvGMAGICAL(sv)
365 || (SvRMAGICAL(sv) && mg_find(sv, PERL_MAGIC_tied)))
375 /* --- PP functions -------------------------------------------------------- */
377 /* Be aware that we restore PL_op->op_ppaddr from the pointer table old_pp
378 * value, another extension might have saved our pp replacement as the ppaddr
379 * for this op, so this doesn't ensure that our function will never be called
380 * again. That's why we don't remove the op info from our map, so that it can
381 * still run correctly if required. */
383 /* ... pp_rv2av ............................................................ */
385 STATIC OP *a_pp_rv2av(pTHX) {
390 a_map_fetch(PL_op, &oi);
393 if (flags & A_HINT_DEREF) {
395 /* We always need to push an empty array to fool the pp_aelem() that comes
399 av = sv_2mortal((SV *) newAV());
404 PL_op->op_ppaddr = oi.old_pp;
407 return CALL_FPTR(oi.old_pp)(aTHX);
410 /* ... pp_rv2hv ............................................................ */
412 STATIC OP *a_pp_rv2hv(pTHX) {
417 a_map_fetch(PL_op, &oi);
420 if (flags & A_HINT_DEREF) {
424 PL_op->op_ppaddr = oi.old_pp;
427 return CALL_FPTR(oi.old_pp)(aTHX);
430 /* ... pp_deref (aelem,helem,rv2sv,padsv) .................................. */
432 STATIC OP *a_pp_deref(pTHX) {
437 a_map_fetch(PL_op, &oi);
440 if (flags & A_HINT_DEREF) {
445 old_private = PL_op->op_private;
446 PL_op->op_private = ((old_private & ~OPpDEREF) | OPpLVAL_DEFER);
447 o = CALL_FPTR(oi.old_pp)(aTHX);
448 PL_op->op_private = old_private;
450 if (flags & (A_HINT_NOTIFY|A_HINT_STORE)) {
453 if (flags & A_HINT_STRICT)
454 croak("Reference vivification forbidden");
455 else if (flags & A_HINT_WARN)
456 warn("Reference was vivified");
457 else /* A_HINT_STORE */
458 croak("Can't vivify reference");
463 } else if ((flags & ~A_HINT_ROOT)
464 && (PL_op->op_private & OPpDEREF || flags & A_HINT_ROOT)) {
465 /* Decide if the expression must autovivify or not.
466 * This branch should be called only once by expression. */
467 flags = a_map_resolve(PL_op, &oi);
469 /* We need the updated flags value in the deref branch. */
470 if (flags & A_HINT_DEREF)
474 /* This op doesn't need to skip autovivification, so restore the original
476 PL_op->op_ppaddr = oi.old_pp;
478 return CALL_FPTR(oi.old_pp)(aTHX);
481 /* ... pp_root (exists,delete,keys,values) ................................. */
483 STATIC OP *a_pp_root_unop(pTHX) {
487 if (!a_defined(TOPs)) {
489 /* Can only be reached by keys or values */
490 if (GIMME_V == G_SCALAR) {
497 a_map_fetch(PL_op, &oi);
499 return CALL_FPTR(oi.old_pp)(aTHX);
502 STATIC OP *a_pp_root_binop(pTHX) {
506 if (!a_defined(TOPm1s)) {
509 if (PL_op->op_type == OP_EXISTS)
515 a_map_fetch(PL_op, &oi);
517 return CALL_FPTR(oi.old_pp)(aTHX);
520 /* --- Check functions ----------------------------------------------------- */
522 /* ... ck_pad{any,sv} ...................................................... */
524 /* Sadly, the PADSV OPs we are interested in don't trigger the padsv check
525 * function, but are instead manually mutated from a PADANY. This is why we set
526 * PL_ppaddr[OP_PADSV] in the padany check function so that PADSV OPs will have
527 * their op_ppaddr set to our pp_padsv. PL_ppaddr[OP_PADSV] is then reset at the
528 * beginning of every ck_pad{any,sv}. Some unwanted OPs can still call our
529 * pp_padsv, but much less than if we would have set PL_ppaddr[OP_PADSV]
532 STATIC OP *(*a_pp_padsv_saved)(pTHX) = 0;
534 STATIC void a_pp_padsv_save(void) {
535 if (a_pp_padsv_saved)
538 a_pp_padsv_saved = PL_ppaddr[OP_PADSV];
539 PL_ppaddr[OP_PADSV] = a_pp_deref;
542 STATIC void a_pp_padsv_restore(OP *o) {
543 if (!a_pp_padsv_saved)
546 if (o->op_ppaddr == a_pp_deref)
547 o->op_ppaddr = a_pp_padsv_saved;
549 PL_ppaddr[OP_PADSV] = a_pp_padsv_saved;
550 a_pp_padsv_saved = 0;
553 STATIC OP *(*a_old_ck_padany)(pTHX_ OP *) = 0;
555 STATIC OP *a_ck_padany(pTHX_ OP *o) {
558 a_pp_padsv_restore(o);
560 o = CALL_FPTR(a_old_ck_padany)(aTHX_ o);
563 if (hint & A_HINT_DO) {
565 a_map_store_root(o, a_pp_padsv_saved, hint);
572 STATIC OP *(*a_old_ck_padsv)(pTHX_ OP *) = 0;
574 STATIC OP *a_ck_padsv(pTHX_ OP *o) {
577 a_pp_padsv_restore(o);
579 o = CALL_FPTR(a_old_ck_padsv)(aTHX_ o);
582 if (hint & A_HINT_DO) {
583 a_map_store_root(o, o->op_ppaddr, hint);
584 o->op_ppaddr = a_pp_deref;
591 /* ... ck_deref (aelem,helem,rv2sv) ........................................ */
593 /* Those ops appear both at the root and inside an expression but there's no
594 * way to distinguish both situations. Worse, we can't even know if we are in a
595 * modifying context, so the expression can't be resolved yet. It will be at the
596 * first invocation of a_pp_deref() for this expression. */
598 STATIC OP *(*a_old_ck_aelem)(pTHX_ OP *) = 0;
599 STATIC OP *(*a_old_ck_helem)(pTHX_ OP *) = 0;
600 STATIC OP *(*a_old_ck_rv2sv)(pTHX_ OP *) = 0;
602 STATIC OP *a_ck_deref(pTHX_ OP *o) {
603 OP * (*old_ck)(pTHX_ OP *o) = 0;
606 switch (o->op_type) {
608 old_ck = a_old_ck_aelem;
609 if ((hint & A_HINT_DO) && !(hint & A_HINT_STRICT)) {
610 OP *kid = cUNOPo->op_first;
612 if (kid->op_type == OP_RV2AV && kid->op_ppaddr != a_pp_rv2av
613 && kUNOP->op_first->op_type != OP_GV
614 && a_map_fetch(kid, &oi)) {
615 a_map_store(kid, kid->op_ppaddr, o, hint);
616 kid->op_ppaddr = a_pp_rv2av;
621 old_ck = a_old_ck_helem;
622 if ((hint & A_HINT_DO) && !(hint & A_HINT_STRICT)) {
623 OP *kid = cUNOPo->op_first;
625 if (kid->op_type == OP_RV2HV && kid->op_ppaddr != a_pp_rv2hv
626 && kUNOP->op_first->op_type != OP_GV
627 && a_map_fetch(kid, &oi)) {
628 a_map_store(kid, kid->op_ppaddr, o, hint);
629 kid->op_ppaddr = a_pp_rv2hv;
634 old_ck = a_old_ck_rv2sv;
637 o = CALL_FPTR(old_ck)(aTHX_ o);
639 if (hint & A_HINT_DO) {
640 a_map_store_root(o, o->op_ppaddr, hint);
641 o->op_ppaddr = a_pp_deref;
648 /* ... ck_rv2xv (rv2av,rv2hv) .............................................. */
650 /* Those ops also appear both inisde and at the root, hence the caveats for
651 * a_ck_deref() still apply here. Since a padsv/rv2sv must appear before a
652 * rv2[ah]v, resolution is handled by the first call to a_pp_deref() in the
655 STATIC OP *(*a_old_ck_rv2av)(pTHX_ OP *) = 0;
656 STATIC OP *(*a_old_ck_rv2hv)(pTHX_ OP *) = 0;
658 STATIC OP *a_ck_rv2xv(pTHX_ OP *o) {
659 OP * (*old_ck)(pTHX_ OP *o) = 0;
660 OP * (*new_pp)(pTHX) = 0;
663 switch (o->op_type) {
664 case OP_RV2AV: old_ck = a_old_ck_rv2av; new_pp = a_pp_rv2av; break;
665 case OP_RV2HV: old_ck = a_old_ck_rv2hv; new_pp = a_pp_rv2hv; break;
667 o = CALL_FPTR(old_ck)(aTHX_ o);
669 if (cUNOPo->op_first->op_type == OP_GV)
673 if (hint & A_HINT_DO && !(hint & A_HINT_STRICT)) {
674 a_map_store_root(o, o->op_ppaddr, hint);
675 o->op_ppaddr = new_pp;
682 /* ... ck_root (exists,delete,keys,values) ................................. */
684 /* Those ops are only found at the root of a dereferencing expression. We can
685 * then resolve at compile time if vivification must take place or not. */
687 STATIC OP *(*a_old_ck_exists)(pTHX_ OP *) = 0;
688 STATIC OP *(*a_old_ck_delete)(pTHX_ OP *) = 0;
689 STATIC OP *(*a_old_ck_keys) (pTHX_ OP *) = 0;
690 STATIC OP *(*a_old_ck_values)(pTHX_ OP *) = 0;
692 STATIC OP *a_ck_root(pTHX_ OP *o) {
693 OP * (*old_ck)(pTHX_ OP *o) = 0;
694 OP * (*new_pp)(pTHX) = 0;
695 bool enabled = FALSE;
698 switch (o->op_type) {
700 old_ck = a_old_ck_exists;
701 new_pp = a_pp_root_binop;
702 enabled = hint & A_HINT_EXISTS;
705 old_ck = a_old_ck_delete;
706 new_pp = a_pp_root_binop;
707 enabled = hint & A_HINT_DELETE;
710 old_ck = a_old_ck_keys;
711 new_pp = a_pp_root_unop;
712 enabled = hint & A_HINT_FETCH;
715 old_ck = a_old_ck_values;
716 new_pp = a_pp_root_unop;
717 enabled = hint & A_HINT_FETCH;
720 o = CALL_FPTR(old_ck)(aTHX_ o);
722 if (hint & A_HINT_DO) {
724 a_map_update_flags_topdown(o, hint | A_HINT_DEREF);
725 a_map_store_root(o, o->op_ppaddr, hint);
726 o->op_ppaddr = new_pp;
736 STATIC U32 a_initialized = 0;
738 /* --- XS ------------------------------------------------------------------ */
740 MODULE = autovivification PACKAGE = autovivification
746 if (!a_initialized++) {
749 a_op_map = ptable_new();
751 MUTEX_INIT(&a_op_map_mutex);
754 PERL_HASH(a_hash, __PACKAGE__, __PACKAGE_LEN__);
756 a_old_ck_padany = PL_check[OP_PADANY];
757 PL_check[OP_PADANY] = MEMBER_TO_FPTR(a_ck_padany);
758 a_old_ck_padsv = PL_check[OP_PADSV];
759 PL_check[OP_PADSV] = MEMBER_TO_FPTR(a_ck_padsv);
761 a_old_ck_aelem = PL_check[OP_AELEM];
762 PL_check[OP_AELEM] = MEMBER_TO_FPTR(a_ck_deref);
763 a_old_ck_helem = PL_check[OP_HELEM];
764 PL_check[OP_HELEM] = MEMBER_TO_FPTR(a_ck_deref);
765 a_old_ck_rv2sv = PL_check[OP_RV2SV];
766 PL_check[OP_RV2SV] = MEMBER_TO_FPTR(a_ck_deref);
768 a_old_ck_rv2av = PL_check[OP_RV2AV];
769 PL_check[OP_RV2AV] = MEMBER_TO_FPTR(a_ck_rv2xv);
770 a_old_ck_rv2hv = PL_check[OP_RV2HV];
771 PL_check[OP_RV2HV] = MEMBER_TO_FPTR(a_ck_rv2xv);
773 a_old_ck_exists = PL_check[OP_EXISTS];
774 PL_check[OP_EXISTS] = MEMBER_TO_FPTR(a_ck_root);
775 a_old_ck_delete = PL_check[OP_DELETE];
776 PL_check[OP_DELETE] = MEMBER_TO_FPTR(a_ck_root);
777 a_old_ck_keys = PL_check[OP_KEYS];
778 PL_check[OP_KEYS] = MEMBER_TO_FPTR(a_ck_root);
779 a_old_ck_values = PL_check[OP_VALUES];
780 PL_check[OP_VALUES] = MEMBER_TO_FPTR(a_ck_root);
782 stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
783 newCONSTSUB(stash, "A_HINT_STRICT", newSVuv(A_HINT_STRICT));
784 newCONSTSUB(stash, "A_HINT_WARN", newSVuv(A_HINT_WARN));
785 newCONSTSUB(stash, "A_HINT_FETCH", newSVuv(A_HINT_FETCH));
786 newCONSTSUB(stash, "A_HINT_STORE", newSVuv(A_HINT_STORE));
787 newCONSTSUB(stash, "A_HINT_EXISTS", newSVuv(A_HINT_EXISTS));
788 newCONSTSUB(stash, "A_HINT_DELETE", newSVuv(A_HINT_DELETE));
789 newCONSTSUB(stash, "A_HINT_MASK", newSVuv(A_HINT_MASK));
797 RETVAL = a_tag(SvOK(hint) ? SvUV(hint) : 0);
807 RETVAL = newSVuv(a_detag(tag));