X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=autovivification.xs;h=688669372bcf96029dacc40cbd7b5efcee721eca;hb=167a7d1ceb42868217cdc88690f5d565527b3d6c;hp=b307fcbaf205f58c0e9d9a934e6ee0ea73f55a29;hpb=66a75622a9e10465ef5117c5c68a78e493406234;p=perl%2Fmodules%2Fautovivification.git

diff --git a/autovivification.xs b/autovivification.xs
index b307fcb..6886693 100644
--- a/autovivification.xs
+++ b/autovivification.xs
@@ -21,66 +21,73 @@
 
 #if A_WORKAROUND_REQUIRE_PROPAGATION
 
-typedef struct {
- UV  bits;
- I32 requires;
-} a_hint_t;
+#define A_ENCODE_UV(B, U)   \
+ len = 0;                   \
+ while (len < sizeof(UV)) { \
+  (B)[len++] = (U) & 0xFF;  \
+  (U) >>= 8;                \
+ }
+
+#define A_DECODE_UV(U, B)        \
+ len = sizeof(UV);               \
+ while (len > 0)                 \
+  (U) = ((U) << 8) | (B)[--len];
 
 STATIC SV *a_tag(pTHX_ UV bits) {
 #define a_tag(B) a_tag(aTHX_ (B))
- SV *tag;
- a_hint_t h;
-
- h.bits = bits;
-
- {
-  const PERL_SI *si;
-  I32            requires = 0;
+ SV            *hint;
+ const PERL_SI *si;
+ UV             requires = 0;
+ unsigned char  buf[sizeof(UV) * 2];
+ STRLEN         len;
 
-  for (si = PL_curstackinfo; si; si = si->si_prev) {
-   I32 cxix;
+ for (si = PL_curstackinfo; si; si = si->si_prev) {
+  I32 cxix;
 
-   for (cxix = si->si_cxix; cxix >= 0; --cxix) {
-    const PERL_CONTEXT *cx = si->si_cxstack + cxix;
+  for (cxix = si->si_cxix; cxix >= 0; --cxix) {
+   const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 
-    if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE)
-     ++requires;
-   }
+   if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE)
+    ++requires;
   }
-
-  h.requires = requires;
  }
 
- return newSVpvn((const char *) &h, sizeof h);
+ A_ENCODE_UV(buf,              requires);
+ A_ENCODE_UV(buf + sizeof(UV), bits);
+ hint = newSVpvn(buf, sizeof buf);
+ SvREADONLY_on(hint);
+
+ return hint;
 }
 
 STATIC UV a_detag(pTHX_ const SV *hint) {
 #define a_detag(H) a_detag(aTHX_ (H))
- const a_hint_t *h;
+ const PERL_SI *si;
+ UV             requires = 0, requires_max = 0, bits = 0;
+ unsigned char *buf;
+ STRLEN         len;
 
  if (!(hint && SvOK(hint)))
   return 0;
 
- h = (const a_hint_t *) SvPVX(hint);
-
- {
-  const PERL_SI *si;
-  I32            requires = 0;
+ buf = SvPVX(hint);
+ A_DECODE_UV(requires_max, buf);
 
-  for (si = PL_curstackinfo; si; si = si->si_prev) {
-   I32 cxix;
+ for (si = PL_curstackinfo; si; si = si->si_prev) {
+  I32 cxix;
 
-   for (cxix = si->si_cxix; cxix >= 0; --cxix) {
-    const PERL_CONTEXT *cx = si->si_cxstack + cxix;
+  for (cxix = si->si_cxix; cxix >= 0; --cxix) {
+   const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 
-    if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE
-                               && ++requires > h->requires)
-     return 0;
-   }
+   if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE
+                              && ++requires > requires_max)
+    return 0;
   }
  }
 
- return h->bits;
+ A_DECODE_UV(bits, buf + sizeof(UV));
+
+ return bits;
 }
 
 #else /* A_WORKAROUND_REQUIRE_PROPAGATION */
@@ -102,13 +109,14 @@ STATIC UV a_detag(pTHX_ const SV *hint) {
 #define A_HINT_MASK   (A_HINT_NOTIFY|A_HINT_DO)
 
 /* Only used in op flags */
-#define A_HINT_DEREF  64
+#define A_HINT_ROOT   64
+#define A_HINT_DEREF  128
 
 STATIC U32 a_hash = 0;
 
 STATIC UV a_hint(pTHX) {
 #define a_hint() a_hint(aTHX)
- const SV *hint;
+ SV *hint;
 #if A_HAS_PERL(5, 9, 5)
  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
                                        NULL,
@@ -128,8 +136,8 @@ STATIC UV a_hint(pTHX) {
 
 typedef struct {
  OP *(*old_pp)(pTHX);
- const OP *root;
  UV flags;
+ void *next;
 } a_op_info;
 
 #define PTABLE_NAME        ptable_map
@@ -146,47 +154,54 @@ STATIC ptable *a_op_map = NULL;
 STATIC perl_mutex a_op_map_mutex;
 #endif
 
-STATIC void a_map_store(pPTBLMS_ const OP *o, OP *(*old_pp)(pTHX), UV flags) {
-#define a_map_store(O, PP, F) a_map_store(aPTBLMS_ (O), (PP), (F))
- a_op_info *oi;
+STATIC const a_op_info *a_map_fetch(const OP *o, a_op_info *oi) {
+ const a_op_info *val;
 
 #ifdef USE_ITHREADS
  MUTEX_LOCK(&a_op_map_mutex);
 #endif
 
+ val = ptable_fetch(a_op_map, o);
+ if (val) {
+  *oi = *val;
+  val = oi;
+ }
+
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&a_op_map_mutex);
+#endif
+
+ return val;
+}
+
+STATIC const a_op_info *a_map_store_locked(pPTBLMS_ const OP *o, OP *(*old_pp)(pTHX), void *next, UV flags) {
+#define a_map_store_locked(O, PP, N, F) a_map_store_locked(aPTBLMS_ (O), (PP), (N), (F))
+ a_op_info *oi;
+
  if (!(oi = ptable_fetch(a_op_map, o))) {
   oi = PerlMemShared_malloc(sizeof *oi);
   ptable_map_store(a_op_map, o, oi);
  }
 
  oi->old_pp = old_pp;
- oi->root   = NULL;
+ oi->next   = next;
  oi->flags  = flags;
 
-#ifdef USE_ITHREADS
- MUTEX_UNLOCK(&a_op_map_mutex);
-#endif
+ return oi;
 }
 
-STATIC const a_op_info *a_map_fetch(const OP *o, a_op_info *oi) {
- const a_op_info *val;
+STATIC void a_map_store(pPTBLMS_ const OP *o, OP *(*old_pp)(pTHX), void *next, UV flags) {
+#define a_map_store(O, PP, N, F) a_map_store(aPTBLMS_ (O), (PP), (N), (F))
 
 #ifdef USE_ITHREADS
  MUTEX_LOCK(&a_op_map_mutex);
 #endif
 
- val = ptable_fetch(a_op_map, o);
- if (val) {
-  *oi = *val;
-  val = oi;
- } else
-  oi->old_pp = 0;
+ a_map_store_locked(o, old_pp, next, flags);
 
 #ifdef USE_ITHREADS
  MUTEX_UNLOCK(&a_op_map_mutex);
 #endif
-
- return val;
 }
 
 STATIC void a_map_delete(pTHX_ const OP *o) {
@@ -202,7 +217,24 @@ STATIC void a_map_delete(pTHX_ const OP *o) {
 #endif
 }
 
-STATIC void a_map_set_root(const OP *root, UV flags) {
+STATIC const OP *a_map_descend(const OP *o) {
+ switch (PL_opargs[o->op_type] & OA_CLASS_MASK) {
+  case OA_BASEOP:
+  case OA_UNOP:
+  case OA_BINOP:
+  case OA_BASEOP_OR_UNOP:
+   return cUNOPo->op_first;
+  case OA_LIST:
+  case OA_LISTOP:
+   return cLISTOPo->op_last;
+ }
+
+ return NULL;
+}
+
+STATIC void a_map_store_root(pPTBLMS_ const OP *root, OP *(*old_pp)(pTHX), UV flags) {
+#define a_map_store_root(R, PP, F) a_map_store_root(aPTBLMS_ (R), (PP), (F))
+ const a_op_info *roi;
  a_op_info *oi;
  const OP *o = root;
 
@@ -210,30 +242,70 @@ STATIC void a_map_set_root(const OP *root, UV flags) {
  MUTEX_LOCK(&a_op_map_mutex);
 #endif
 
- while (o) {
-  if (oi = ptable_fetch(a_op_map, o)) {
-   oi->root  = root;
-   oi->flags = flags;
+ roi = a_map_store_locked(o, old_pp, (OP *) root, flags | A_HINT_ROOT);
+
+ while (o->op_flags & OPf_KIDS) {
+  o = a_map_descend(o);
+  if (!o)
+   break;
+  if ((oi = ptable_fetch(a_op_map, o))) {
+   oi->flags &= ~A_HINT_ROOT;
+   oi->next   = (a_op_info *) roi;
+   break;
   }
+ }
+
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&a_op_map_mutex);
+#endif
+
+ return;
+}
+
+STATIC void a_map_update_flags_topdown(const OP *root, UV flags) {
+ a_op_info *oi;
+ const OP *o = root;
+
+#ifdef USE_ITHREADS
+ MUTEX_LOCK(&a_op_map_mutex);
+#endif
+
+ flags &= ~A_HINT_ROOT;
+
+ do {
+  if ((oi = ptable_fetch(a_op_map, o)))
+   oi->flags = (oi->flags & A_HINT_ROOT) | flags;
   if (!(o->op_flags & OPf_KIDS))
    break;
-  switch (PL_opargs[o->op_type] & OA_CLASS_MASK) {
-   case OA_BASEOP:
-   case OA_UNOP:
-   case OA_BINOP:
-   case OA_BASEOP_OR_UNOP:
-    o = cUNOPo->op_first;
-    break;
-   case OA_LIST:
-   case OA_LISTOP:
-    o = cLISTOPo->op_last;
-    break;
-   default:
-    goto done;
-  }
+  o = a_map_descend(o);
+ } while (o);
+
+#ifdef USE_ITHREADS
+ MUTEX_UNLOCK(&a_op_map_mutex);
+#endif
+
+ return;
+}
+
+#define a_map_cancel(R) a_map_update_flags_topdown((R), 0)
+
+STATIC void a_map_update_flags_bottomup(const OP *o, UV flags, UV rflags) {
+ a_op_info *oi;
+
+#ifdef USE_ITHREADS
+ MUTEX_LOCK(&a_op_map_mutex);
+#endif
+
+ flags  &= ~A_HINT_ROOT;
+ rflags |=  A_HINT_ROOT;
+
+ oi = ptable_fetch(a_op_map, o);
+ while (!(oi->flags & A_HINT_ROOT)) {
+  oi->flags = flags;
+  oi        = oi->next;
  }
+ oi->flags = rflags;
 
-done:
 #ifdef USE_ITHREADS
  MUTEX_UNLOCK(&a_op_map_mutex);
 #endif
@@ -241,6 +313,41 @@ done:
  return;
 }
 
+/* ... Decide whether this expression should be autovivified or not ........ */
+
+STATIC UV a_map_resolve(const OP *o, a_op_info *oi) {
+ UV flags = 0, rflags;
+ const OP *root;
+ a_op_info *roi = oi;
+
+ while (!(roi->flags & A_HINT_ROOT))
+  roi = roi->next;
+ if (!roi)
+  goto cancel;
+
+ rflags = roi->flags & ~A_HINT_ROOT;
+ if (!rflags)
+  goto cancel;
+
+ root = roi->next;
+ if (root->op_flags & OPf_MOD) {
+  if (rflags & A_HINT_STORE)
+   flags = (A_HINT_STORE|A_HINT_DEREF);
+ } else if (rflags & A_HINT_FETCH)
+   flags = (A_HINT_FETCH|A_HINT_DEREF);
+
+ if (!flags) {
+cancel:
+  a_map_update_flags_bottomup(o, 0, 0);
+  return 0;
+ }
+
+ flags |= (rflags & A_HINT_NOTIFY);
+ a_map_update_flags_bottomup(o, flags, 0);
+
+ return oi->flags & A_HINT_ROOT ? 0 : flags;
+}
+
 /* ... Lightweight pp_defined() ............................................ */
 
 STATIC bool a_defined(pTHX_ SV *sv) {
@@ -267,23 +374,34 @@ STATIC bool a_defined(pTHX_ SV *sv) {
 
 /* --- PP functions -------------------------------------------------------- */
 
+/* Be aware that we restore PL_op->op_ppaddr from the pointer table old_pp
+ * value, another extension might have saved our pp replacement as the ppaddr
+ * for this op, so this doesn't ensure that our function will never be called
+ * again. That's why we don't remove the op info from our map, so that it can
+ * still run correctly if required. */
+
 /* ... pp_rv2av ............................................................ */
 
 STATIC OP *a_pp_rv2av(pTHX) {
  a_op_info oi;
- UV hint;
+ UV flags;
  dSP;
 
  a_map_fetch(PL_op, &oi);
+ flags = oi.flags;
 
- if (PL_op != oi.root && !SvOK(TOPs)) {
-  /* We always need to push an empty array to fool the pp_aelem() that comes
-   * later. */
-  SV *av;
-  POPs;
-  av = sv_2mortal((SV *) newAV());
-  PUSHs(av);
-  RETURN;
+ if (flags & A_HINT_DEREF) {
+  if (!SvOK(TOPs)) {
+   /* We always need to push an empty array to fool the pp_aelem() that comes
+    * later. */
+   SV *av;
+   POPs;
+   av = sv_2mortal((SV *) newAV());
+   PUSHs(av);
+   RETURN;
+  }
+ } else {
+  PL_op->op_ppaddr = oi.old_pp;
  }
 
  return CALL_FPTR(oi.old_pp)(aTHX);
@@ -293,19 +411,17 @@ STATIC OP *a_pp_rv2av(pTHX) {
 
 STATIC OP *a_pp_rv2hv(pTHX) {
  a_op_info oi;
- UV hint;
+ UV flags;
  dSP;
 
  a_map_fetch(PL_op, &oi);
+ flags = oi.flags;
 
- if (PL_op != oi.root && !SvOK(TOPs)) {
-  if (oi.root->op_flags & OPf_MOD) {
-   SV *hv;
-   POPs;
-   hv = sv_2mortal((SV *) newHV());
-   PUSHs(hv);
-  }
-  RETURN;
+ if (flags & A_HINT_DEREF) {
+  if (!SvOK(TOPs))
+   RETURN;
+ } else {
+  PL_op->op_ppaddr = oi.old_pp;
  }
 
  return CALL_FPTR(oi.old_pp)(aTHX);
@@ -313,9 +429,6 @@ STATIC OP *a_pp_rv2hv(pTHX) {
 
 /* ... pp_deref (aelem,helem,rv2sv,padsv) .................................. */
 
-STATIC const char a_msg_forbidden[]  = "Reference vivification forbidden";
-STATIC const char a_msg_impossible[] = "Can't vivify reference";
-
 STATIC OP *a_pp_deref(pTHX) {
  a_op_info oi;
  UV flags;
@@ -338,43 +451,30 @@ deref:
    SPAGAIN;
    if (!SvOK(TOPs)) {
     if (flags & A_HINT_STRICT)
-     croak(a_msg_forbidden);
+     croak("Reference vivification forbidden");
     else if (flags & A_HINT_WARN)
-      warn(a_msg_forbidden);
+      warn("Reference was vivified");
     else /* A_HINT_STORE */
-     croak(a_msg_impossible);
+     croak("Can't vivify reference");
    }
   }
 
   return o;
- } else if (flags && (PL_op->op_private & OPpDEREF || PL_op == oi.root)) {
-  oi.flags = flags & A_HINT_NOTIFY;
-
-  if ((oi.root->op_flags & (OPf_MOD|OPf_REF)) != (OPf_MOD|OPf_REF)) {
-   if (flags & A_HINT_FETCH)
-    oi.flags |= (A_HINT_FETCH|A_HINT_DEREF);
-  } else if (flags & A_HINT_STORE)
-    oi.flags |= (A_HINT_STORE|A_HINT_DEREF);
-
-  if (PL_op == oi.root)
-   oi.flags &= ~A_HINT_DEREF;
-
-  /* We will need the updated flags value in the deref part */
-  flags = oi.flags;
+ } else if ((flags & ~A_HINT_ROOT)
+                    && (PL_op->op_private & OPpDEREF || flags & A_HINT_ROOT)) {
+  /* Decide if the expression must autovivify or not.
+   * This branch should be called only once by expression. */
+  flags = a_map_resolve(PL_op, &oi);
 
+  /* We need the updated flags value in the deref branch. */
   if (flags & A_HINT_DEREF)
    goto deref;
-
-  /* This op doesn't need to skip autovivification, so restore the original
-   * state. Be aware that another extension might have saved a_pp_deref as the
-   * ppaddr for this op, so restoring PL_op->op_ppaddr doesn't ensure that this
-   * function will never be called again. That's why we don't remove the op info
-   * from our map and we reset oi.flags to 0, so that it can still run correctly
-   * if required. */
-  oi.flags = 0;
-  PL_op->op_ppaddr = oi.old_pp;
  }
 
+ /* This op doesn't need to skip autovivification, so restore the original
+  * state. */
+ PL_op->op_ppaddr = oi.old_pp;
+
  return CALL_FPTR(oi.old_pp)(aTHX);
 }
 
@@ -419,6 +519,20 @@ STATIC OP *a_pp_root_binop(pTHX) {
 
 /* --- Check functions ----------------------------------------------------- */
 
+STATIC void a_recheck_rv2xv(pTHX_ OP *o, OPCODE type, OP *(*new_pp)(pTHX)) {
+#define a_recheck_rv2xv(O, T, PP) a_recheck_rv2xv(aTHX_ (O), (T), (PP))
+ a_op_info oi;
+
+ if (o->op_type == type && o->op_ppaddr != new_pp
+                        && cUNOPo->op_first->op_type != OP_GV
+                        && a_map_fetch(o, &oi)) {
+  a_map_store(o, o->op_ppaddr, oi.next, oi.flags);
+  o->op_ppaddr = new_pp;
+ }
+
+ return;
+}
+
 /* ... ck_pad{any,sv} ...................................................... */
 
 /* Sadly, the PADSV OPs we are interested in don't trigger the padsv check
@@ -462,7 +576,7 @@ STATIC OP *a_ck_padany(pTHX_ OP *o) {
  hint = a_hint();
  if (hint & A_HINT_DO) {
   a_pp_padsv_save();
-  a_map_store(o, a_pp_padsv_saved, hint);
+  a_map_store_root(o, a_pp_padsv_saved, hint);
  } else
   a_map_delete(o);
 
@@ -480,7 +594,7 @@ STATIC OP *a_ck_padsv(pTHX_ OP *o) {
 
  hint = a_hint();
  if (hint & A_HINT_DO) {
-  a_map_store(o, o->op_ppaddr, hint);
+  a_map_store_root(o, o->op_ppaddr, hint);
   o->op_ppaddr = a_pp_deref;
  } else
   a_map_delete(o);
@@ -490,26 +604,39 @@ STATIC OP *a_ck_padsv(pTHX_ OP *o) {
 
 /* ... ck_deref (aelem,helem,rv2sv) ........................................ */
 
+/* Those ops appear both at the root and inside an expression but there's no
+ * way to distinguish both situations. Worse, we can't even know if we are in a
+ * modifying context, so the expression can't be resolved yet. It will be at the
+ * first invocation of a_pp_deref() for this expression. */
+
 STATIC OP *(*a_old_ck_aelem)(pTHX_ OP *) = 0;
 STATIC OP *(*a_old_ck_helem)(pTHX_ OP *) = 0;
 STATIC OP *(*a_old_ck_rv2sv)(pTHX_ OP *) = 0;
 
 STATIC OP *a_ck_deref(pTHX_ OP *o) {
  OP * (*old_ck)(pTHX_ OP *o) = 0;
- UV hint;
+ UV hint = a_hint();
 
  switch (o->op_type) {
-  case OP_AELEM: old_ck = a_old_ck_aelem; break;
-  case OP_HELEM: old_ck = a_old_ck_helem; break;
-  case OP_RV2SV: old_ck = a_old_ck_rv2sv; break;
+  case OP_AELEM:
+   old_ck = a_old_ck_aelem;
+   if ((hint & A_HINT_DO) && !(hint & A_HINT_STRICT))
+    a_recheck_rv2xv(cUNOPo->op_first, OP_RV2AV, a_pp_rv2av);
+   break;
+  case OP_HELEM:
+   old_ck = a_old_ck_helem;
+   if ((hint & A_HINT_DO) && !(hint & A_HINT_STRICT))
+    a_recheck_rv2xv(cUNOPo->op_first, OP_RV2HV, a_pp_rv2hv);
+   break;
+  case OP_RV2SV:
+   old_ck = a_old_ck_rv2sv;
+   break;
  }
  o = CALL_FPTR(old_ck)(aTHX_ o);
 
- hint = a_hint();
  if (hint & A_HINT_DO) {
-  a_map_store(o, o->op_ppaddr, hint);
+  a_map_store_root(o, o->op_ppaddr, hint);
   o->op_ppaddr = a_pp_deref;
-  a_map_set_root(o, hint);
  } else
   a_map_delete(o);
 
@@ -518,6 +645,11 @@ STATIC OP *a_ck_deref(pTHX_ OP *o) {
 
 /* ... ck_rv2xv (rv2av,rv2hv) .............................................. */
 
+/* Those ops also appear both inisde and at the root, hence the caveats for
+ * a_ck_deref() still apply here. Since a padsv/rv2sv must appear before a
+ * rv2[ah]v, resolution is handled by the first call to a_pp_deref() in the
+ * expression. */
+
 STATIC OP *(*a_old_ck_rv2av)(pTHX_ OP *) = 0;
 STATIC OP *(*a_old_ck_rv2hv)(pTHX_ OP *) = 0;
 
@@ -532,20 +664,23 @@ STATIC OP *a_ck_rv2xv(pTHX_ OP *o) {
  }
  o = CALL_FPTR(old_ck)(aTHX_ o);
 
+ if (cUNOPo->op_first->op_type == OP_GV)
+  return o;
+
  hint = a_hint();
- if (hint & A_HINT_DO) {
-  if (!(hint & A_HINT_STRICT)) {
-   a_map_store(o, o->op_ppaddr, hint);
-   o->op_ppaddr = new_pp;
-  }
-  a_map_set_root(o, hint);
+ if (hint & A_HINT_DO && !(hint & A_HINT_STRICT)) {
+  a_map_store_root(o, o->op_ppaddr, hint);
+  o->op_ppaddr = new_pp;
  } else
   a_map_delete(o);
 
  return o;
 }
 
-/* ... ck_root (exists,delete) ............................................. */
+/* ... ck_root (exists,delete,keys,values) ................................. */
+
+/* Those ops are only found at the root of a dereferencing expression. We can
+ * then resolve at compile time if vivification must take place or not. */
 
 STATIC OP *(*a_old_ck_exists)(pTHX_ OP *) = 0;
 STATIC OP *(*a_old_ck_delete)(pTHX_ OP *) = 0;
@@ -584,11 +719,11 @@ STATIC OP *a_ck_root(pTHX_ OP *o) {
 
  if (hint & A_HINT_DO) {
   if (enabled) {
-   a_map_set_root(o, hint | A_HINT_DEREF);
-   a_map_store(o, o->op_ppaddr, hint);
+   a_map_update_flags_topdown(o, hint | A_HINT_DEREF);
+   a_map_store_root(o, o->op_ppaddr, hint);
    o->op_ppaddr = new_pp;
   } else {
-   a_map_set_root(o, 0);
+   a_map_cancel(o);
   }
  } else
   a_map_delete(o);