X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=Upper.xs;h=f90f31917886f4c1eef471e1da9f72e3b5bbd3b5;hb=7c2b31131b09869b8021b94eb18d14b0df4b356c;hp=fadbe3d8f7d2733687c11372e4c86c165d07ccd2;hpb=0c640ded3d3d3939e6fb99c3a94c6bf6e54a360a;p=perl%2Fmodules%2FScope-Upper.git

diff --git a/Upper.xs b/Upper.xs
index fadbe3d..f90f319 100644
--- a/Upper.xs
+++ b/Upper.xs
@@ -3,7 +3,7 @@
 
 #define PERL_NO_GET_CONTEXT
 #include "EXTERN.h"
-#include "perl.h" 
+#include "perl.h"
 #include "XSUB.h"
 
 #define __PACKAGE__ "Scope::Upper"
@@ -116,6 +116,11 @@ STATIC SV *su_newSV_type(pTHX_ svtype t) {
 # define CvISXSUB(C) CvXSUB(C)
 #endif
 
+#ifndef PadlistARRAY
+# define PadlistARRAY(P) AvARRAY(P)
+# define PadARRAY(P)     AvARRAY(P)
+#endif
+
 #ifndef CxHASARGS
 # define CxHASARGS(C) ((C)->blk_sub.hasargs)
 #endif
@@ -128,6 +133,22 @@ STATIC SV *su_newSV_type(pTHX_ svtype t) {
 # define gv_fetchpvn_flags(A, B, C, D) gv_fetchpv((A), (C), (D))
 #endif
 
+#ifndef OP_GIMME_REVERSE
+STATIC U8 su_op_gimme_reverse(U8 gimme) {
+ switch (gimme) {
+  case G_VOID:
+   return OPf_WANT_VOID;
+  case G_ARRAY:
+   return OPf_WANT_LIST;
+  default:
+   break;
+ }
+
+ return OPf_WANT_SCALAR;
+}
+#define OP_GIMME_REVERSE(G) su_op_gimme_reverse(G)
+#endif
+
 #ifndef PERL_MAGIC_tied
 # define PERL_MAGIC_tied 'P'
 #endif
@@ -179,6 +200,134 @@ STATIC SV *su_newSV_type(pTHX_ svtype t) {
 # define MY_CXT_CLONE NOOP
 #endif
 
+/* --- Unique context ID global storage ------------------------------------ */
+
+/* ... Sequence ID counter ................................................. */
+
+typedef struct {
+ UV     *seqs;
+ STRLEN  size;
+} su_uv_array;
+
+STATIC su_uv_array su_uid_seq_counter;
+
+#ifdef USE_ITHREADS
+
+STATIC perl_mutex su_uid_seq_counter_mutex;
+
+#define SU_LOCK(M)   MUTEX_LOCK(M)
+#define SU_UNLOCK(M) MUTEX_UNLOCK(M)
+
+#else /* USE_ITHREADS */
+
+#define SU_LOCK(M)
+#define SU_UNLOCK(M)
+
+#endif /* !USE_ITHREADS */
+
+STATIC UV su_uid_seq_next(pTHX_ UV depth) {
+#define su_uid_seq_next(D) su_uid_seq_next(aTHX_ (D))
+ UV seq;
+ UV *seqs;
+
+ SU_LOCK(&su_uid_seq_counter_mutex);
+
+ seqs = su_uid_seq_counter.seqs;
+
+ if (depth >= su_uid_seq_counter.size) {
+  UV i;
+
+  seqs = PerlMemShared_realloc(seqs, (depth + 1) * sizeof(UV));
+  for (i = su_uid_seq_counter.size; i <= depth; ++i)
+   seqs[i] = 0;
+
+  su_uid_seq_counter.seqs = seqs;
+  su_uid_seq_counter.size = depth + 1;
+ }
+
+ seq = ++seqs[depth];
+
+ SU_UNLOCK(&su_uid_seq_counter_mutex);
+
+ return seq;
+}
+
+/* ... UID storage ......................................................... */
+
+typedef struct {
+ UV  seq;
+ U32 flags;
+} su_uid;
+
+#define SU_UID_ACTIVE 1
+
+STATIC UV su_uid_depth(pTHX_ I32 cxix) {
+#define su_uid_depth(I) su_uid_depth(aTHX_ (I))
+ const PERL_SI *si;
+ UV depth;
+
+ depth = cxix;
+ for (si = PL_curstackinfo->si_prev; si; si = si->si_prev)
+  depth += si->si_cxix + 1;
+
+ return depth;
+}
+
+typedef struct {
+ su_uid **map;
+ STRLEN   used;
+ STRLEN   alloc;
+} su_uid_storage;
+
+STATIC void su_uid_storage_dup(pTHX_ su_uid_storage *new_cxt, const su_uid_storage *old_cxt, UV max_depth) {
+#define su_uid_storage_dup(N, O, D) su_uid_storage_dup(aTHX_ (N), (O), (D))
+ su_uid **old_map = old_cxt->map;
+
+ if (old_map) {
+  su_uid **new_map = new_cxt->map;
+  STRLEN old_used  = old_cxt->used;
+  STRLEN old_alloc = old_cxt->alloc;
+  STRLEN new_used, new_alloc;
+  STRLEN i;
+
+  new_used = max_depth < old_used ? max_depth : old_used;
+  new_cxt->used = new_used;
+
+  if (new_used <= new_cxt->alloc)
+   new_alloc = new_cxt->alloc;
+  else {
+   new_alloc = new_used;
+   Renew(new_map, new_alloc, su_uid *);
+   for (i = new_cxt->alloc; i < new_alloc; ++i)
+    new_map[i] = NULL;
+   new_cxt->map   = new_map;
+   new_cxt->alloc = new_alloc;
+  }
+
+  for (i = 0; i < new_alloc; ++i) {
+   su_uid *new_uid = new_map[i];
+
+   if (i < new_used) { /* => i < max_depth && i < old_used */
+    su_uid *old_uid = old_map[i];
+
+    if (old_uid && (old_uid->flags & SU_UID_ACTIVE)) {
+     if (!new_uid) {
+      Newx(new_uid, 1, su_uid);
+      new_map[i] = new_uid;
+     }
+     *new_uid = *old_uid;
+     continue;
+    }
+   }
+
+   if (new_uid)
+    new_uid->flags &= ~SU_UID_ACTIVE;
+  }
+ }
+
+ return;
+}
+
 /* --- unwind() global storage --------------------------------------------- */
 
 typedef struct {
@@ -191,29 +340,35 @@ typedef struct {
 
 /* --- uplevel() data tokens and global storage ---------------------------- */
 
+#define SU_UPLEVEL_HIJACKS_RUNOPS SU_HAS_PERL(5, 8, 0)
+
 typedef struct {
- void *next;
+ void          *next;
 
- I32  cxix;
- bool died;
+ su_uid_storage tmp_uid_storage;
+ su_uid_storage old_uid_storage;
 
- CV  *target;
- I32  target_depth;
+ I32            cxix;
 
- CV  *callback;
- I32  callback_depth;
- CV  *renamed;
+ I32            target_depth;
+ CV            *target;
 
- AV *fake_argarray;
+ CV            *callback;
+ CV            *renamed;
 
- PERL_SI *si;
- PERL_SI *old_curstackinfo;
- AV      *old_mainstack;
+ PERL_SI       *si;
+ PERL_SI       *old_curstackinfo;
+ AV            *old_mainstack;
 
- COP *old_curcop;
+ COP           *old_curcop;
 
- bool old_catch;
- OP  *old_op;
+ OP            *old_op;
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+ runops_proc_t  old_runops;
+#endif
+ bool           old_catch;
+
+ bool           died;
 } su_uplevel_ud;
 
 STATIC su_uplevel_ud *su_uplevel_ud_new(pTHX) {
@@ -224,6 +379,10 @@ STATIC su_uplevel_ud *su_uplevel_ud_new(pTHX) {
  Newx(sud, 1, su_uplevel_ud);
  sud->next = NULL;
 
+ sud->tmp_uid_storage.map   = NULL;
+ sud->tmp_uid_storage.used  = 0;
+ sud->tmp_uid_storage.alloc = 0;
+
  Newx(si, 1, PERL_SI);
  si->si_stack   = newAV();
  AvREAL_off(si->si_stack);
@@ -242,12 +401,25 @@ STATIC void su_uplevel_ud_delete(pTHX_ su_uplevel_ud *sud) {
  Safefree(si->si_cxstack);
  SvREFCNT_dec(si->si_stack);
  Safefree(si);
+
+ if (sud->tmp_uid_storage.map) {
+  su_uid **map   = sud->tmp_uid_storage.map;
+  STRLEN   alloc = sud->tmp_uid_storage.alloc;
+  STRLEN   i;
+
+  for (i = 0; i < alloc; ++i)
+   Safefree(map[i]);
+
+  Safefree(map);
+ }
+
  Safefree(sud);
 
  return;
 }
 
 typedef struct {
+ su_uplevel_ud *top;
  su_uplevel_ud *root;
  I32            count;
 } su_uplevel_storage;
@@ -264,6 +436,7 @@ typedef struct {
  char               *stack_placeholder;
  su_unwind_storage   unwind_storage;
  su_uplevel_storage  uplevel_storage;
+ su_uid_storage      uid_storage;
 } my_cxt_t;
 
 START_MY_CXT
@@ -508,6 +681,8 @@ typedef struct {
 
 /* ... Reap ................................................................ */
 
+#define SU_SAVE_LAST_CX (!SU_HAS_PERL(5, 8, 4) || (SU_HAS_PERL(5, 9, 5) && !SU_HAS_PERL(5, 14, 0)) || SU_HAS_PERL(5, 15, 0))
+
 typedef struct {
  su_ud_common ci;
  SV *cb;
@@ -515,10 +690,10 @@ typedef struct {
 
 STATIC void su_call(pTHX_ void *ud_) {
  su_ud_reap *ud = (su_ud_reap *) ud_;
-#if SU_HAS_PERL(5, 9, 5)
- PERL_CONTEXT saved_cx;
+#if SU_SAVE_LAST_CX
  I32 cxix;
-#endif
+ PERL_CONTEXT saved_cx;
+#endif /* SU_SAVE_LAST_CX */
 
  dSP;
 
@@ -534,22 +709,18 @@ STATIC void su_call(pTHX_ void *ud_) {
  PUSHMARK(SP);
  PUTBACK;
 
+#if SU_SAVE_LAST_CX
  /* If the recently popped context isn't saved there, it will be overwritten by
   * the sub scope from call_sv, although it's still needed in our caller. */
-
-#if SU_HAS_PERL(5, 9, 5)
- if (cxstack_ix < cxstack_max)
-  cxix = cxstack_ix + 1;
- else
-  cxix = Perl_cxinc(aTHX);
+ cxix     = (cxstack_ix < cxstack_max) ? (cxstack_ix + 1) : Perl_cxinc(aTHX);
  saved_cx = cxstack[cxix];
-#endif
+#endif /* SU_SAVE_LAST_CX */
 
  call_sv(ud->cb, G_VOID);
 
-#if SU_HAS_PERL(5, 9, 5)
+#if SU_SAVE_LAST_CX
  cxstack[cxix] = saved_cx;
-#endif
+#endif /* SU_SAVE_LAST_CX */
 
  PUTBACK;
 
@@ -738,9 +909,9 @@ done:
 
 #if SU_DEBUG
 # ifdef DEBUGGING
-#  define SU_CXNAME PL_block_type[CxTYPE(&cxstack[cxstack_ix])]
+#  define SU_CXNAME(C) PL_block_type[CxTYPE(C)]
 # else
-#  define SU_CXNAME "XXX"
+#  define SU_CXNAME(C) "XXX"
 # endif
 #endif
 
@@ -753,7 +924,7 @@ STATIC void su_pop(pTHX_ void *ud) {
   PerlIO_printf(Perl_debug_log,
    "%p: --- pop a %s\n"
    "%p: leave scope     at depth=%2d scope_ix=%2d cur_top=%2d cur_base=%2d\n",
-    ud, SU_CXNAME,
+    ud, SU_CXNAME(cxstack + cxstack_ix),
     ud, depth, PL_scopestack_ix,PL_savestack_ix,PL_scopestack[PL_scopestack_ix])
  );
 
@@ -824,19 +995,6 @@ STATIC I32 su_init(pTHX_ void *ud, I32 cxix, I32 size) {
  for (i = cxstack_ix; i > cxix; --i) {
   PERL_CONTEXT *cx = cxstack + i;
   switch (CxTYPE(cx)) {
-#if SU_HAS_PERL(5, 10, 0)
-   case CXt_BLOCK:
-    SU_D(PerlIO_printf(Perl_debug_log, "%p: cx %d is block\n", ud, i));
-    /* Given and when blocks are actually followed by a simple block, so skip
-     * it if needed. */
-    if (cxix > 0) { /* Implies i > 0 */
-     PERL_CONTEXT *next = cx - 1;
-     if (CxTYPE(next) == CXt_GIVEN || CxTYPE(next) == CXt_WHEN)
-      --cxix;
-    }
-    depth++;
-    break;
-#endif
 #if SU_HAS_PERL(5, 11, 0)
    case CXt_LOOP_FOR:
    case CXt_LOOP_PLAIN:
@@ -945,28 +1103,13 @@ STATIC void su_unwind(pTHX_ void *ud_) {
 
 /* --- Uplevel ------------------------------------------------------------- */
 
-#ifndef OP_GIMME_REVERSE
-STATIC U8 su_op_gimme_reverse(U8 gimme) {
- switch (gimme) {
-  case G_VOID:
-   return OPf_WANT_VOID;
-  case G_ARRAY:
-   return OPf_WANT_LIST;
-  default:
-   break;
- }
-
- return OPf_WANT_SCALAR;
-}
-#define OP_GIMME_REVERSE(G) su_op_gimme_reverse(G)
-#endif
-
 #define SU_UPLEVEL_SAVE(f, t) STMT_START { sud->old_##f = PL_##f; PL_##f = (t); } STMT_END
 #define SU_UPLEVEL_RESTORE(f) STMT_START { PL_##f = sud->old_##f; } STMT_END
 
-STATIC su_uplevel_ud *su_uplevel_storage_new(pTHX) {
-#define su_uplevel_storage_new() su_uplevel_storage_new(aTHX)
+STATIC su_uplevel_ud *su_uplevel_storage_new(pTHX_ I32 cxix) {
+#define su_uplevel_storage_new(I) su_uplevel_storage_new(aTHX_ (I))
  su_uplevel_ud *sud;
+ UV depth;
  dMY_CXT;
 
  sud = MY_CXT.uplevel_storage.root;
@@ -977,6 +1120,14 @@ STATIC su_uplevel_ud *su_uplevel_storage_new(pTHX) {
   sud = su_uplevel_ud_new();
  }
 
+ sud->next = MY_CXT.uplevel_storage.top;
+ MY_CXT.uplevel_storage.top = sud;
+
+ depth = su_uid_depth(cxix);
+ su_uid_storage_dup(&sud->tmp_uid_storage, &MY_CXT.uid_storage, depth);
+ sud->old_uid_storage = MY_CXT.uid_storage;
+ MY_CXT.uid_storage   = sud->tmp_uid_storage;
+
  return sud;
 }
 
@@ -984,6 +1135,20 @@ STATIC void su_uplevel_storage_delete(pTHX_ su_uplevel_ud *sud) {
 #define su_uplevel_storage_delete(S) su_uplevel_storage_delete(aTHX_ (S))
  dMY_CXT;
 
+ sud->tmp_uid_storage = MY_CXT.uid_storage;
+ MY_CXT.uid_storage   = sud->old_uid_storage;
+ {
+  su_uid **map;
+  UV  i, alloc;
+  map   = sud->tmp_uid_storage.map;
+  alloc = sud->tmp_uid_storage.alloc;
+  for (i = 0; i < alloc; ++i) {
+   if (map[i])
+    map[i]->flags &= SU_UID_ACTIVE;
+  }
+ }
+ MY_CXT.uplevel_storage.top = sud->next;
+
  if (MY_CXT.uplevel_storage.count >= SU_UPLEVEL_STORAGE_SIZE) {
   su_uplevel_ud_delete(sud);
  } else {
@@ -993,49 +1158,137 @@ STATIC void su_uplevel_storage_delete(pTHX_ su_uplevel_ud *sud) {
  }
 }
 
-#define SU_HAS_EXT_MAGIC SU_HAS_PERL(5, 8, 0)
+STATIC int su_uplevel_goto_static(const OP *o) {
+ for (; o; o = o->op_sibling) {
+  /* goto ops are unops with kids. */
+  if (!(o->op_flags & OPf_KIDS))
+   continue;
 
-#if SU_HAS_EXT_MAGIC && !SU_HAS_PERL(5, 13, 7)
+  switch (o->op_type) {
+   case OP_LEAVEEVAL:
+   case OP_LEAVETRY:
+    /* Don't care about gotos inside eval, as they are forbidden at run time. */
+    break;
+   case OP_GOTO:
+    return 1;
+   default:
+    if (su_uplevel_goto_static(cUNOPo->op_first))
+     return 1;
+    break;
+  }
+ }
 
-STATIC int su_uplevel_restore_free(pTHX_ SV *sv, MAGIC *mg) {
- su_uplevel_storage_delete((su_uplevel_ud *) mg->mg_ptr);
+ return 0;
+}
+
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+
+STATIC int su_uplevel_goto_runops(pTHX) {
+#define su_uplevel_goto_runops() su_uplevel_goto_runops(aTHX)
+ register OP *op;
+ dVAR;
+
+ op = PL_op;
+ do {
+  if (op->op_type == OP_GOTO) {
+   AV  *argarray = NULL;
+   I32  cxix;
+
+   for (cxix = cxstack_ix; cxix >= 0; --cxix) {
+    const PERL_CONTEXT *cx = cxstack + cxix;
+
+    switch (CxTYPE(cx)) {
+     case CXt_SUB:
+      if (CxHASARGS(cx)) {
+       argarray = cx->blk_sub.argarray;
+       goto done;
+      }
+      break;
+     case CXt_EVAL:
+     case CXt_FORMAT:
+      goto done;
+     default:
+      break;
+    }
+   }
+
+done:
+   if (argarray) {
+    dMY_CXT;
+
+    if (MY_CXT.uplevel_storage.top->cxix == cxix) {
+     AV  *args  = GvAV(PL_defgv);
+     I32  items = AvFILLp(args);
+
+     av_extend(argarray, items);
+     Copy(AvARRAY(args), AvARRAY(argarray), items + 1, SV *);
+     AvFILLp(argarray) = items;
+    }
+   }
+  }
+
+  PL_op = op = op->op_ppaddr(aTHX);
+
+#if !SU_HAS_PERL(5, 13, 0)
+  PERL_ASYNC_CHECK();
+#endif
+ } while (op);
+
+ TAINT_NOT;
 
  return 0;
 }
 
-STATIC MGVTBL su_uplevel_restore_vtbl = {
- 0,
- 0,
- 0,
- 0,
- su_uplevel_restore_free
-};
+#endif /* SU_UPLEVEL_HIJACKS_RUNOPS */
 
-#endif /* SU_HAS_EXT_MAGIC && !SU_HAS_PERL(5, 13, 7) */
+#define su_at_underscore(C) PadARRAY(PadlistARRAY(CvPADLIST(C))[CvDEPTH(C)])[0]
 
 STATIC void su_uplevel_restore(pTHX_ void *sus_) {
  su_uplevel_ud *sud = sus_;
  PERL_SI *cur = sud->old_curstackinfo;
  PERL_SI *si  = sud->si;
 
- /* When we reach this place, POPSUB has already been called (with our fake
-  * argarray). GvAV(PL_defgv) points to the savearray (that is, what @_ was
-  * before uplevel). argarray is either the fake AV we created in su_uplevel()
-  * or some empty replacement POPSUB creates when @_ is reified. In both cases
-  * we have to destroy it before the context stack is swapped back to its
-  * original state. */
- SvREFCNT_dec(sud->fake_argarray);
-
- /* PUSHSUB was exerted with the original callback, but after calling
-  * pp_entersub() we hijacked the blk_sub.cv member of the fresh sub context
-  * with the renamed CV. Thus POPSUB and LEAVESUB applied to this CV, not the
-  * original. Repair this imbalance right now. */
- if (!(CvDEPTH(sud->callback) = sud->callback_depth))
-  LEAVESUB(sud->callback);
-
- /* Free the renamed cv. */
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+ if (PL_runops == su_uplevel_goto_runops)
+  PL_runops = sud->old_runops;
+#endif
+
+ if (sud->callback) {
+  PERL_CONTEXT *cx = cxstack + sud->cxix;
+  AV     *argarray = MUTABLE_AV(su_at_underscore(sud->callback));
+
+  /* We have to fix the pad entry for @_ in the original callback because it
+   * may have been reified. */
+  if (AvREAL(argarray)) {
+   const I32 fill = AvFILLp(argarray);
+   SvREFCNT_dec(argarray);
+   argarray = newAV();
+   AvREAL_off(argarray);
+   AvREIFY_on(argarray);
+   av_extend(argarray, fill);
+   su_at_underscore(sud->callback) = MUTABLE_SV(argarray);
+  } else {
+   CLEAR_ARGARRAY(argarray);
+  }
+
+  /* If the old cv member is our renamed CV, it means that this place has been
+   * reached without a goto() happening, and the old argarray member is
+   * actually our fake argarray. Destroy it properly in that case. */
+  if (cx->blk_sub.cv == sud->renamed) {
+   SvREFCNT_dec(cx->blk_sub.argarray);
+   cx->blk_sub.argarray = argarray;
+  }
+
+  CvDEPTH(sud->callback)--;
+  SvREFCNT_dec(sud->callback);
+ }
+
+ /* Free the renamed CV. We must do it ourselves so that we can force the
+  * depth to be 0, or perl would complain about it being "still in use".
+  * But we *know* that it cannot be so. */
  if (sud->renamed) {
-  CvDEPTH(sud->renamed) = 0;
+  CvDEPTH(sud->renamed)   = 0;
+  CvPADLIST(sud->renamed) = NULL;
   SvREFCNT_dec(sud->renamed);
  }
 
@@ -1132,20 +1385,15 @@ found_it:
  /* This issue has been fixed in perl with commit 8f89e5a9, which was made
   * public in perl 5.13.7. */
  su_uplevel_storage_delete(sud);
-#elif SU_HAS_EXT_MAGIC
- /* If 'ext' magic is available, we work around this by attaching the state
-  * data to a scalar that will be freed "soon". */
- {
-  SV *sv = sv_newmortal();
-
-  sv_magicext(sv, NULL, PERL_MAGIC_ext, &su_uplevel_restore_vtbl,
-                        (const char *) sud, 0);
- }
 #else
  /* Otherwise, we just enqueue it back in the global storage list. */
  {
   dMY_CXT;
 
+  sud->tmp_uid_storage = MY_CXT.uid_storage;
+  MY_CXT.uid_storage   = sud->old_uid_storage;
+
+  MY_CXT.uplevel_storage.top  = sud->next;
   sud->next = MY_CXT.uplevel_storage.root;
   MY_CXT.uplevel_storage.root = sud;
   MY_CXT.uplevel_storage.count++;
@@ -1158,12 +1406,6 @@ found_it:
 STATIC CV *su_cv_clone(pTHX_ CV *proto, GV *gv) {
 #define su_cv_clone(P, G) su_cv_clone(aTHX_ (P), (G))
  dVAR;
- AV        *protopadlist = CvPADLIST(proto);
- const AV  *protopadname = (const AV *) *av_fetch(protopadlist, 0, FALSE);
- SV       **pname        = AvARRAY(protopadname);
- const I32  fpadlist     = AvFILLp(protopadlist);
- const I32  fpadname     = AvFILLp(protopadname);
- AV *padlist, *padname;
  CV *cv;
 
  cv = MUTABLE_CV(newSV_type(SvTYPE(proto)));
@@ -1189,15 +1431,21 @@ STATIC CV *su_cv_clone(pTHX_ CV *proto, GV *gv) {
   Perl_sv_add_backref(aTHX_ CvSTASH(proto), MUTABLE_SV(cv));
 #endif
 
- OP_REFCNT_LOCK;
- CvROOT(cv)        = OpREFCNT_inc(CvROOT(proto));
- OP_REFCNT_UNLOCK;
- CvSTART(cv)       = CvSTART(proto);
+ if (CvISXSUB(proto)) {
+  CvXSUB(cv)       = CvXSUB(proto);
+  CvXSUBANY(cv)    = CvXSUBANY(proto);
+ } else {
+  OP_REFCNT_LOCK;
+  CvROOT(cv)       = OpREFCNT_inc(CvROOT(proto));
+  OP_REFCNT_UNLOCK;
+  CvSTART(cv)      = CvSTART(proto);
+ }
  CvOUTSIDE(cv)     = CvOUTSIDE(proto);
 #ifdef CVf_WEAKOUTSIDE
  if (!(CvFLAGS(proto) & CVf_WEAKOUTSIDE))
 #endif
   SvREFCNT_inc_simple_void(CvOUTSIDE(cv));
+ CvPADLIST(cv)     = CvPADLIST(proto);
 #ifdef CvOUTSIDE_SEQ
  CvOUTSIDE_SEQ(cv) = CvOUTSIDE_SEQ(proto);
 #endif
@@ -1205,51 +1453,6 @@ STATIC CV *su_cv_clone(pTHX_ CV *proto, GV *gv) {
  if (SvPOK(proto))
   sv_setpvn(MUTABLE_SV(cv), SvPVX_const(proto), SvCUR(proto));
 
- padlist = newAV();
- AvREAL_off(padlist);
- av_fill(padlist, fpadlist);
- CvPADLIST(cv) = padlist;
-
- padname = newAV();
- av_fill(padname, fpadname);
- if (fpadname >= 0) {
-  I32 j;
-  SV **psvp = AvARRAY(protopadname);
-  SV **svp  = AvARRAY(padname);
-
-  svp[0] = &PL_sv_undef;
-  for (j = 1; j <= fpadname; ++j)
-   svp[j] = SvREFCNT_inc(psvp[j]);
- }
- AvARRAY(padlist)[0] = MUTABLE_SV(padname);
-
- if (fpadlist >= 1) {
-  I32 i;
-
-  for (i = 1; i <= fpadlist; ++i) {
-   AV  *protoframe = MUTABLE_AV(AvARRAY(protopadlist)[i]);
-   AV  *frame      = newAV();
-   SV **psvp       = AvARRAY(protoframe);
-   SV **svp;
-   I32  j,  fframe = AvFILLp(protoframe);
-
-   av_fill(frame, fframe);
-   svp = AvARRAY(frame);
-   if (i == 1) {
-    AV *a0 = newAV(); /* will be @_ */
-    AvREAL_off(a0);
-    AvREIFY_on(a0);
-    svp[0] = MUTABLE_SV(a0);
-   } else {
-    svp[0] = SvREFCNT_inc(psvp[0]);
-   }
-   for (j = 1; j <= fframe; ++j)
-    svp[j] = SvREFCNT_inc(psvp[j]);
-
-   AvARRAY(padlist)[i] = MUTABLE_SV(frame);
-  }
- }
-
 #ifdef CvCONST
  if (CvCONST(cv))
   CvCONST_off(cv);
@@ -1266,6 +1469,7 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
  PERL_SI *cur = PL_curstackinfo;
  SV **old_stack_sp;
  CV  *target;
+ CV  *renamed;
  UNOP sub_op;
  I32  gimme;
  I32  old_mark, new_mark;
@@ -1280,13 +1484,12 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
  old_mark = AvFILLp(PL_curstack) = PL_stack_sp - PL_stack_base;
  SPAGAIN;
 
- sud = su_uplevel_storage_new();
+ sud = su_uplevel_storage_new(cxix);
 
- sud->cxix          = cxix;
- sud->died          = 1;
- sud->callback      = callback;
- sud->renamed       = NULL;
- sud->fake_argarray = NULL;
+ sud->cxix     = cxix;
+ sud->died     = 1;
+ sud->callback = NULL;
+ sud->renamed  = NULL;
  SAVEDESTRUCTOR_X(su_uplevel_restore, sud);
 
  si = sud->si;
@@ -1344,11 +1547,14 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
   sud->old_mainstack = NULL;
  PL_curstack = si->si_stack;
 
+ renamed      = su_cv_clone(callback, CvGV(target));
+ sud->renamed = renamed;
+
  PUSHMARK(SP);
  /* Both SP and old_stack_sp point just before the CV. */
  Copy(old_stack_sp + 2, SP + 1, args, SV *);
  SP += args;
- PUSHs((SV *) callback);
+ PUSHs((SV *) renamed);
  PUTBACK;
 
  Zero(&sub_op, 1, UNOP);
@@ -1360,24 +1566,21 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
 
  SU_UPLEVEL_SAVE(op, (OP *) &sub_op);
 
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+ sud->old_runops = PL_runops;
+#endif
+
  sud->old_catch = CATCH_GET;
  CATCH_SET(TRUE);
 
  if ((PL_op = PL_ppaddr[OP_ENTERSUB](aTHX))) {
   PERL_CONTEXT *sub_cx = cxstack + cxstack_ix;
-  CV *renamed;
 
-  sud->callback_depth = sub_cx->blk_sub.olddepth;
+  /* If pp_entersub() returns a non-null OP, it means that the callback is not
+   * an XSUB. */
 
-  renamed      = su_cv_clone(callback, CvGV(target));
-  sud->renamed = renamed;
-
-  sub_cx->blk_sub.cv = renamed;
-  if (!sub_cx->blk_sub.olddepth) {
-   SvREFCNT_inc_simple_void(renamed);
-   SvREFCNT_inc_simple_void(renamed);
-   SAVEFREESV(renamed);
-  }
+  sud->callback = MUTABLE_CV(SvREFCNT_inc(callback));
+  CvDEPTH(callback)++;
 
   if (CxHASARGS(cx) && cx->blk_sub.argarray) {
    /* The call to pp_entersub() has saved the current @_ (in XS terms,
@@ -1387,6 +1590,7 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
     * argarray with an unreal copy of the original @_. */
    AV *av = newAV();
    AvREAL_off(av);
+   AvREIFY_on(av);
    av_extend(av, AvMAX(cx->blk_sub.argarray));
    AvFILLp(av) = AvFILLp(cx->blk_sub.argarray);
    Copy(AvARRAY(cx->blk_sub.argarray), AvARRAY(av), AvFILLp(av) + 1, SV *);
@@ -1394,17 +1598,29 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
   } else {
    SvREFCNT_inc_simple_void(sub_cx->blk_sub.argarray);
   }
-  sud->fake_argarray = sub_cx->blk_sub.argarray;
 
-  CALLRUNOPS(aTHX);
+  if (su_uplevel_goto_static(CvROOT(renamed))) {
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+   if (PL_runops != PL_runops_std) {
+    if (PL_runops == PL_runops_dbg) {
+     if (PL_debug)
+      croak("uplevel() can't execute code that calls goto when debugging flags are set");
+    } else if (PL_runops != su_uplevel_goto_runops)
+     croak("uplevel() can't execute code that calls goto with a custom runloop");
+   }
+
+   PL_runops = su_uplevel_goto_runops;
+#else  /* SU_UPLEVEL_HIJACKS_RUNOPS */
+   croak("uplevel() can't execute code that calls goto before perl 5.8");
+#endif /* !SU_UPLEVEL_HIJACKS_RUNOPS */
+  }
 
-  ret = PL_stack_sp - (PL_stack_base + new_mark);
+  CALLRUNOPS(aTHX);
  }
 
  sud->died = 0;
 
- SPAGAIN;
-
+ ret = PL_stack_sp - (PL_stack_base + new_mark);
  if (ret > 0) {
   AV *old_stack = sud->old_curstackinfo->si_stack;
 
@@ -1419,19 +1635,252 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
   AvFILLp(old_stack) += ret;
  }
 
- PUTBACK;
-
  LEAVE;
 
  return ret;
 }
 
+/* --- Unique context ID --------------------------------------------------- */
+
+STATIC su_uid *su_uid_storage_fetch(pTHX_ UV depth) {
+#define su_uid_storage_fetch(D) su_uid_storage_fetch(aTHX_ (D))
+ su_uid **map, *uid;
+ STRLEN alloc;
+ dMY_CXT;
+
+ map   = MY_CXT.uid_storage.map;
+ alloc = MY_CXT.uid_storage.alloc;
+
+ if (depth >= alloc) {
+  STRLEN i;
+
+  Renew(map, depth + 1, su_uid *);
+  for (i = alloc; i <= depth; ++i)
+   map[i] = NULL;
+
+  MY_CXT.uid_storage.map   = map;
+  MY_CXT.uid_storage.alloc = depth + 1;
+ }
+
+ uid = map[depth];
+
+ if (!uid) {
+  Newx(uid, 1, su_uid);
+  uid->seq   = 0;
+  uid->flags = 0;
+  map[depth] = uid;
+ }
+
+ if (depth >= MY_CXT.uid_storage.used)
+  MY_CXT.uid_storage.used = depth + 1;
+
+ return uid;
+}
+
+STATIC int su_uid_storage_check(pTHX_ UV depth, UV seq) {
+#define su_uid_storage_check(D, S) su_uid_storage_check(aTHX_ (D), (S))
+ su_uid *uid;
+ dMY_CXT;
+
+ if (depth >= MY_CXT.uid_storage.used)
+  return 0;
+
+ uid = MY_CXT.uid_storage.map[depth];
+
+ return uid && (uid->seq == seq) && (uid->flags & SU_UID_ACTIVE);
+}
+
+STATIC void su_uid_drop(pTHX_ void *ud_) {
+ su_uid *uid = ud_;
+
+ uid->flags &= ~SU_UID_ACTIVE;
+}
+
+STATIC void su_uid_bump(pTHX_ void *ud_) {
+ su_ud_reap *ud  = ud_;
+
+ SAVEDESTRUCTOR_X(su_uid_drop, ud->cb);
+}
+
+STATIC SV *su_uid_get(pTHX_ I32 cxix) {
+#define su_uid_get(I) su_uid_get(aTHX_ (I))
+ su_uid *uid;
+ SV *uid_sv;
+ UV depth;
+
+ depth = su_uid_depth(cxix);
+ uid   = su_uid_storage_fetch(depth);
+
+ if (!(uid->flags & SU_UID_ACTIVE)) {
+  su_ud_reap *ud;
+
+  uid->seq = su_uid_seq_next(depth);
+  uid->flags |= SU_UID_ACTIVE;
+
+  Newx(ud, 1, su_ud_reap);
+  SU_UD_ORIGIN(ud)  = NULL;
+  SU_UD_HANDLER(ud) = su_uid_bump;
+  ud->cb = (SV *) uid;
+  su_init(ud, cxix, SU_SAVE_DESTRUCTOR_SIZE);
+ }
+
+ uid_sv = sv_newmortal();
+ sv_setpvf(uid_sv, "%"UVuf"-%"UVuf, depth, uid->seq);
+ return uid_sv;
+}
+
+#ifdef grok_number
+
+#define su_grok_number(S, L, VP) grok_number((S), (L), (VP))
+
+#else /* grok_number */
+
+#define IS_NUMBER_IN_UV 0x1
+
+STATIC int su_grok_number(pTHX_ const char *s, STRLEN len, UV *valuep) {
+#define su_grok_number(S, L, VP) su_grok_number(aTHX_ (S), (L), (VP))
+ STRLEN i;
+ SV *tmpsv;
+
+ /* This crude check should be good enough for a fallback implementation.
+  * Better be too strict than too lax. */
+ for (i = 0; i < len; ++i) {
+  if (!isDIGIT(s[i]))
+   return 0;
+ }
+
+ tmpsv = sv_newmortal();
+ sv_setpvn(tmpsv, s, len);
+ *valuep = sv_2uv(tmpsv);
+
+ return IS_NUMBER_IN_UV;
+}
+
+#endif /* !grok_number */
+
+STATIC int su_uid_validate(pTHX_ SV *uid) {
+#define su_uid_validate(U) su_uid_validate(aTHX_ (U))
+ const char *s;
+ STRLEN len, p = 0;
+ UV depth, seq;
+ int type;
+
+ s = SvPV_const(uid, len);
+
+ while (p < len && s[p] != '-')
+  ++p;
+ if (p >= len)
+  croak("UID contains only one part");
+
+ type = su_grok_number(s, p, &depth);
+ if (type != IS_NUMBER_IN_UV)
+  croak("First UID part is not an unsigned integer");
+
+ ++p; /* Skip '-'. As we used to have p < len, len - (p + 1) >= 0. */
+
+ type = su_grok_number(s + p, len - p, &seq);
+ if (type != IS_NUMBER_IN_UV)
+  croak("Second UID part is not an unsigned integer");
+
+ return su_uid_storage_check(depth, seq);
+}
+
+/* --- Context operations -------------------------------------------------- */
+
+/* Remove sequences of BLOCKs having DB for stash, followed by a SUB context
+ * for the debugger callback. */
+
+STATIC I32 su_context_skip_db(pTHX_ I32 cxix) {
+#define su_context_skip_db(C) su_context_skip_db(aTHX_ (C))
+ I32 i;
+
+ if (!PL_DBsub)
+  return cxix;
+
+ for (i = cxix; i > 0; --i) {
+  PERL_CONTEXT *cx = cxstack + i;
+
+  switch (CxTYPE(cx)) {
+   case CXt_BLOCK:
+    if (cx->blk_oldcop && CopSTASH(cx->blk_oldcop) == GvSTASH(PL_DBgv))
+     continue;
+    break;
+   case CXt_SUB:
+    if (cx->blk_sub.cv == GvCV(PL_DBsub)) {
+     cxix = i - 1;
+     continue;
+    }
+    break;
+   default:
+    break;
+  }
+
+  break;
+ }
+
+ return cxix;
+}
+
+STATIC I32 su_context_up(pTHX_ I32 cxix) {
+#define su_context_up(C) su_context_up(aTHX_ (C))
+ PERL_CONTEXT *cx;
+
+ if (cxix <= 0)
+  return 0;
+
+ cx = cxstack + cxix;
+ if (CxTYPE(cx) == CXt_BLOCK) {
+  PERL_CONTEXT *prev = cx - 1;
+
+  switch (CxTYPE(prev)) {
+#if SU_HAS_PERL(5, 10, 0)
+   case CXt_GIVEN:
+   case CXt_WHEN:
+#endif
+#if SU_HAS_PERL(5, 11, 0)
+   /* That's the only subcategory that can cause an extra BLOCK context */
+   case CXt_LOOP_PLAIN:
+#else
+   case CXt_LOOP:
+#endif
+    if (cx->blk_oldcop == prev->blk_oldcop)
+     cxix -= 2;
+    else
+     --cxix;
+    break;
+   case CXt_SUBST:
+    if (cx->blk_oldcop && cx->blk_oldcop->op_sibling
+                       && cx->blk_oldcop->op_sibling->op_type == OP_SUBST)
+     cxix -= 2;
+    else
+     --cxix;
+    break;
+   default:
+    --cxix;
+    break;
+  }
+ } else {
+  --cxix;
+ }
+
+ return cxix;
+}
+
 /* --- Interpreter setup/teardown ------------------------------------------ */
 
 STATIC void su_teardown(pTHX_ void *param) {
  su_uplevel_ud *cur;
+ su_uid **map;
  dMY_CXT;
 
+ map = MY_CXT.uid_storage.map;
+ if (map) {
+  STRLEN i;
+  for (i = 0; i < MY_CXT.uid_storage.used; ++i)
+   Safefree(map[i]);
+  Safefree(map);
+ }
+
  cur = MY_CXT.uplevel_storage.root;
  if (cur) {
   su_uplevel_ud *prev;
@@ -1460,9 +1909,14 @@ STATIC void su_setup(pTHX) {
  MY_CXT.unwind_storage.proxy_op.op_type   = OP_STUB;
  MY_CXT.unwind_storage.proxy_op.op_ppaddr = NULL;
 
+ MY_CXT.uplevel_storage.top   = NULL;
  MY_CXT.uplevel_storage.root  = NULL;
  MY_CXT.uplevel_storage.count = 0;
 
+ MY_CXT.uid_storage.map   = NULL;
+ MY_CXT.uid_storage.used  = 0;
+ MY_CXT.uid_storage.alloc = 0;
+
  call_atexit(su_teardown, NULL);
 
  return;
@@ -1470,34 +1924,6 @@ STATIC void su_setup(pTHX) {
 
 /* --- XS ------------------------------------------------------------------ */
 
-#if SU_HAS_PERL(5, 8, 9)
-# define SU_SKIP_DB_MAX 2
-#else
-# define SU_SKIP_DB_MAX 3
-#endif
-
-/* Skip context sequences of 1 to SU_SKIP_DB_MAX (included) block contexts
- * followed by a DB sub */
-
-#define SU_SKIP_DB(C) \
- STMT_START {         \
-  I32 skipped = 0;    \
-  PERL_CONTEXT *base = cxstack;      \
-  PERL_CONTEXT *cx   = base + (C);   \
-  while (cx >= base && (C) > skipped && CxTYPE(cx) == CXt_BLOCK) \
-   --cx, ++skipped;                  \
-  if (cx >= base && (C) > skipped) { \
-   switch (CxTYPE(cx)) {  \
-    case CXt_SUB:         \
-     if (skipped <= SU_SKIP_DB_MAX && cx->blk_sub.cv == GvCV(PL_DBsub)) \
-      (C) -= skipped + 1; \
-      break;              \
-    default:              \
-     break;               \
-   }                      \
-  }                       \
- } STMT_END
-
 #define SU_GET_CONTEXT(A, B)   \
  STMT_START {                  \
   if (items > A) {             \
@@ -1512,8 +1938,6 @@ STATIC void su_setup(pTHX) {
   } else {                     \
 default_cx:                    \
    cxix = cxstack_ix;          \
-   if (PL_DBsub)               \
-    SU_SKIP_DB(cxix);          \
   }                            \
  } STMT_END
 
@@ -1545,6 +1969,7 @@ XS(XS_Scope__Upper_unwind) {
  PERL_UNUSED_VAR(ax); /* -Wall */
 
  SU_GET_CONTEXT(0, items - 1);
+ cxix = su_context_skip_db(cxix);
  do {
   PERL_CONTEXT *cx = cxstack + cxix;
   switch (CxTYPE(cx)) {
@@ -1581,6 +2006,11 @@ BOOT:
 {
  HV *stash;
 
+ MUTEX_INIT(&su_uid_seq_counter_mutex);
+
+ su_uid_seq_counter.seqs = NULL;
+ su_uid_seq_counter.size = 0;
+
  stash = gv_stashpv(__PACKAGE__, 1);
  newCONSTSUB(stash, "TOP",           newSViv(0));
  newCONSTSUB(stash, "SU_THREADSAFE", newSVuv(SU_THREADSAFE));
@@ -1595,11 +2025,22 @@ BOOT:
 void
 CLONE(...)
 PROTOTYPE: DISABLE
+PREINIT:
+ su_uid_storage new_cxt;
 PPCODE:
+ {
+  dMY_CXT;
+  new_cxt.map   = NULL;
+  new_cxt.used  = 0;
+  new_cxt.alloc = 0;
+  su_uid_storage_dup(&new_cxt, &MY_CXT.uid_storage, MY_CXT.uid_storage.used);
+ }
  {
   MY_CXT_CLONE;
+  MY_CXT.uplevel_storage.top   = NULL;
   MY_CXT.uplevel_storage.root  = NULL;
   MY_CXT.uplevel_storage.count = 0;
+  MY_CXT.uid_storage           = new_cxt;
  }
  XSRETURN(0);
 
@@ -1609,10 +2050,9 @@ void
 HERE()
 PROTOTYPE:
 PREINIT:
- I32 cxix = cxstack_ix;
+ I32 cxix;
 PPCODE:
- if (PL_DBsub)
-  SU_SKIP_DB(cxix);
+ cxix = su_context_skip_db(cxstack_ix);
  EXTEND(SP, 1);
  mPUSHi(cxix);
  XSRETURN(1);
@@ -1624,10 +2064,9 @@ PREINIT:
  I32 cxix;
 PPCODE:
  SU_GET_CONTEXT(0, 0);
- if (--cxix < 0)
-  cxix = 0;
- if (PL_DBsub)
-  SU_SKIP_DB(cxix);
+ cxix = su_context_skip_db(cxix);
+ cxix = su_context_up(cxix);
+ cxix = su_context_skip_db(cxix);
  EXTEND(SP, 1);
  mPUSHi(cxix);
  XSRETURN(1);
@@ -1681,19 +2120,10 @@ PREINIT:
  I32 cxix, level;
 PPCODE:
  SU_GET_LEVEL(0, 0);
- cxix = cxstack_ix;
- if (PL_DBsub) {
-  SU_SKIP_DB(cxix);
-  while (cxix > 0) {
-   if (--level < 0)
-    break;
-   --cxix;
-   SU_SKIP_DB(cxix);
-  }
- } else {
-  cxix -= level;
-  if (cxix < 0)
-   cxix = 0;
+ cxix = su_context_skip_db(cxstack_ix);
+ while (--level >= 0) {
+  cxix = su_context_up(cxix);
+  cxix = su_context_skip_db(cxix);
  }
  EXTEND(SP, 1);
  mPUSHi(cxix);
@@ -1736,6 +2166,8 @@ PPCODE:
   PERL_CONTEXT *cx = cxstack + cxix--;
   switch (CxTYPE(cx)) {
    case CXt_SUB:
+    if (PL_DBsub && cx->blk_sub.cv == GvCV(PL_DBsub))
+     continue;
    case CXt_EVAL:
    case CXt_FORMAT: {
     I32 gimme = cx->blk_gimme;
@@ -1758,6 +2190,7 @@ PREINIT:
  su_ud_reap *ud;
 CODE:
  SU_GET_CONTEXT(1, 1);
+ cxix = su_context_skip_db(cxix);
  Newx(ud, 1, su_ud_reap);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_reap;
@@ -1773,6 +2206,7 @@ PREINIT:
  su_ud_localize *ud;
 CODE:
  SU_GET_CONTEXT(2, 2);
+ cxix = su_context_skip_db(cxix);
  Newx(ud, 1, su_ud_localize);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
@@ -1791,6 +2225,7 @@ CODE:
   croak("Can't infer the element localization type from a glob and the value");
  SU_GET_CONTEXT(3, 3);
  Newx(ud, 1, su_ud_localize);
+ cxix = su_context_skip_db(cxix);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
  size = su_ud_localize_init(ud, sv, val, elem);
@@ -1809,6 +2244,7 @@ PREINIT:
  su_ud_localize *ud;
 CODE:
  SU_GET_CONTEXT(2, 2);
+ cxix = su_context_skip_db(cxix);
  Newx(ud, 1, su_ud_localize);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
@@ -1848,3 +2284,28 @@ PPCODE:
   }
  } while (--cxix >= 0);
  croak("Can't uplevel outside a subroutine");
+
+void
+uid(...)
+PROTOTYPE: ;$
+PREINIT:
+ I32 cxix;
+ SV *uid;
+PPCODE:
+ SU_GET_CONTEXT(0, 0);
+ cxix = su_context_skip_db(cxix);
+ uid  = su_uid_get(cxix);
+ EXTEND(SP, 1);
+ PUSHs(uid);
+ XSRETURN(1);
+
+void
+validate_uid(SV *uid)
+PROTOTYPE: $
+PREINIT:
+ SV *ret;
+PPCODE:
+ ret = su_uid_validate(uid) ? &PL_sv_yes : &PL_sv_no;
+ EXTEND(SP, 1);
+ PUSHs(ret);
+ XSRETURN(1);