X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FScope-Upper.git;a=blobdiff_plain;f=Upper.xs;h=27397091936b248267348e9bbe075f900311671f;hp=9ab1eaad745b124bd14672ed000951b917553e7e;hb=3beb96a81eebadf62454ea90eecd4b9dd36bdce5;hpb=aa7f19d0069d057cf99b963b2db36e7caccb6b2b

diff --git a/Upper.xs b/Upper.xs
index 9ab1eaa..2739709 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"
@@ -80,6 +80,13 @@ STATIC SV *su_newSV_type(pTHX_ svtype t) {
 # define newSV_type(T) su_newSV_type(aTHX_ (T))
 #endif
 
+#ifdef newSVpvn_flags
+# define su_newmortal_pvn(S, L) newSVpvn_flags((S), (L), SVs_TEMP)
+#else
+# define su_newmortal_pvn(S, L) sv_2mortal(newSVpvn((S), (L)))
+#endif
+#define su_newmortal_pvs(S) su_newmortal_pvn((S), sizeof(S)-1)
+
 #ifndef SvPV_const
 # define SvPV_const(S, L) SvPV(S, L)
 #endif
@@ -116,18 +123,88 @@ 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
 
+#ifndef CxGIMME
+# ifdef G_WANT
+#  define CxGIMME(C) ((C)->blk_gimme & G_WANT)
+# else
+#  define CxGIMME(C) ((C)->blk_gimme)
+# endif
+#endif
+
+#ifndef CxOLD_OP_TYPE
+# define CxOLD_OP_TYPE(C) (C)->blk_eval.old_op_type
+#endif
+
+#ifndef OutCopFILE
+# define OutCopFILE(C) CopFILE(C)
+#endif
+
+#ifndef OutCopFILE_len
+# define OutCopFILE_len(C) strlen(OutCopFILE(C))
+#endif
+
+#ifndef CopHINTS_get
+# define CopHINTS_get(C) ((I32) (C)->op_private & HINT_PRIVATE_MASK)
+#endif
+
+#ifndef CopHINTHASH_get
+# define CopHINTHASH_get(C) (C)->cop_hints_hash
+#endif
+
+#ifndef cophh_2hv
+# define COPHH           struct refcounted_he
+# define cophh_2hv(H, F) Perl_refcounted_he_chain_2hv(aTHX_ (H))
+#endif
+
 #ifndef HvNAME_get
 # define HvNAME_get(H) HvNAME(H)
 #endif
 
+#ifndef HvNAMELEN
+# define HvNAMELEN(H) strlen(HvNAME(H))
+#endif
+
 #ifndef gv_fetchpvn_flags
 # define gv_fetchpvn_flags(A, B, C, D) gv_fetchpv((A), (C), (D))
 #endif
 
+#ifndef hv_fetchs
+# define hv_fetchs(H, K, L) hv_fetch((H), (K), sizeof(K)-1, (L))
+#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 OpSIBLING
+# ifdef OP_SIBLING
+#  define OpSIBLING(O) OP_SIBLING(O)
+# else
+#  define OpSIBLING(O) ((O)->op_sibling)
+# endif
+#endif
+
 #ifndef PERL_MAGIC_tied
 # define PERL_MAGIC_tied 'P'
 #endif
@@ -179,6 +256,133 @@ 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 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 {
@@ -189,28 +393,47 @@ typedef struct {
  OP       proxy_op;
 } su_unwind_storage;
 
+/* --- yield() global storage ---------------------------------------------- */
+
+typedef struct {
+ I32      cxix;
+ I32      items;
+ SV     **savesp;
+ UNOP     leave_op;
+ OP       proxy_op;
+} su_yield_storage;
+
 /* --- 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;
- CV  *renamed;
+ I32            target_depth;
+ CV            *target;
 
- PERL_SI *si;
- PERL_SI *old_curstackinfo;
- AV      *old_mainstack;
+ CV            *callback;
+ CV            *renamed;
+
+ PERL_SI       *si;
+ PERL_SI       *old_curstackinfo;
+ AV            *old_mainstack;
+
+ COP           *old_curcop;
 
- COP *old_curcop;
+ OP            *old_op;
+#if SU_UPLEVEL_HIJACKS_RUNOPS
+ runops_proc_t  old_runops;
+#endif
+ bool           old_catch;
 
- bool old_catch;
- OP  *old_op;
+ bool           died;
 } su_uplevel_ud;
 
 STATIC su_uplevel_ud *su_uplevel_ud_new(pTHX) {
@@ -221,6 +444,10 @@ 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);
@@ -239,12 +466,25 @@ 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;
@@ -260,7 +500,9 @@ typedef struct {
 typedef struct {
  char               *stack_placeholder;
  su_unwind_storage   unwind_storage;
+ su_yield_storage    yield_storage;
  su_uplevel_storage  uplevel_storage;
+ su_uid_storage      uid_storage;
 } my_cxt_t;
 
 START_MY_CXT
@@ -505,6 +747,8 @@ 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;
@@ -512,10 +756,10 @@ 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;
 
@@ -531,22 +775,18 @@ 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;
 
@@ -733,12 +973,10 @@ done:
 
 /* --- Pop a context back -------------------------------------------------- */
 
-#if SU_DEBUG
-# ifdef DEBUGGING
-#  define SU_CXNAME PL_block_type[CxTYPE(&cxstack[cxstack_ix])]
-# else
-#  define SU_CXNAME "XXX"
-# endif
+#if SU_DEBUG && defined(DEBUGGING)
+# define SU_CXNAME(C) PL_block_type[CxTYPE(C)]
+#else
+# define SU_CXNAME(C) "XXX"
 #endif
 
 STATIC void su_pop(pTHX_ void *ud) {
@@ -750,7 +988,7 @@ 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])
  );
 
@@ -821,19 +1059,6 @@ 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:
@@ -902,23 +1127,26 @@ STATIC I32 su_init(pTHX_ void *ud, I32 cxix, I32 size) {
 
 STATIC void su_unwind(pTHX_ void *ud_) {
  dMY_CXT;
- I32 cxix    = MY_CXT.unwind_storage.cxix;
- I32 items   = MY_CXT.unwind_storage.items - 1;
- SV **savesp = MY_CXT.unwind_storage.savesp;
+ I32 cxix  = MY_CXT.unwind_storage.cxix;
+ I32 items = MY_CXT.unwind_storage.items;
  I32 mark;
 
  PERL_UNUSED_VAR(ud_);
 
- if (savesp)
-  PL_stack_sp = savesp;
+ PL_stack_sp = MY_CXT.unwind_storage.savesp;
+#if SU_HAS_PERL(5, 19, 4)
+ {
+  I32 i;
+  SV **sp = PL_stack_sp;
+  for (i = -items + 1; i <= 0; ++i)
+   if (!SvTEMP(sp[i]))
+    sv_2mortal(SvREFCNT_inc(sp[i]));
+ }
+#endif
 
  if (cxstack_ix > cxix)
   dounwind(cxix);
 
- /* Hide the level */
- if (items >= 0)
-  PL_stack_sp--;
-
  mark = PL_markstack[cxstack[cxix].blk_oldmarksp];
  *PL_markstack_ptr = PL_stack_sp - PL_stack_base - items;
 
@@ -940,30 +1168,198 @@ STATIC void su_unwind(pTHX_ void *ud_) {
  PL_op = &(MY_CXT.unwind_storage.proxy_op);
 }
 
-/* --- Uplevel ------------------------------------------------------------- */
+/* --- Yield --------------------------------------------------------------- */
 
-#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;
+#if SU_HAS_PERL(5, 10, 0)
+# define SU_RETOP_SUB(C)   ((C)->blk_sub.retop)
+# define SU_RETOP_EVAL(C)  ((C)->blk_eval.retop)
+# define SU_RETOP_LOOP(C)  ((C)->blk_loop.my_op->op_lastop->op_next)
+# define SU_RETOP_GIVEN(C) ((C)->blk_givwhen.leave_op->op_next)
+#else
+# define SU_RETOP_SUB(C)  ((C)->blk_oldretsp > 0 ? PL_retstack[(C)->blk_oldretsp - 1] : NULL)
+# define SU_RETOP_EVAL(C) SU_RETOP_SUB(C)
+# define SU_RETOP_LOOP(C) ((C)->blk_loop.last_op->op_next)
+#endif
+
+STATIC void su_yield(pTHX_ void *ud_) {
+ dMY_CXT;
+ PERL_CONTEXT *cx;
+ const char   *which = ud_;
+ I32 cxix      = MY_CXT.yield_storage.cxix;
+ I32 items     = MY_CXT.yield_storage.items;
+ opcode  type  = OP_NULL;
+ U8      flags = 0;
+ OP     *next;
+
+ PERL_UNUSED_VAR(ud_);
+
+ cx = cxstack + cxix;
+ switch (CxTYPE(cx)) {
+  case CXt_BLOCK: {
+   I32 i, cur = cxstack_ix, n = 1;
+   OP *o = NULL;
+   /* Is this actually a given/when block? This may occur only when yield was
+    * called with HERE (or nothing) as the context. */
+#if SU_HAS_PERL(5, 10, 0)
+   if (cxix > 0) {
+    PERL_CONTEXT *prev = cx - 1;
+    U8 type = CxTYPE(prev);
+    if ((type == CXt_GIVEN || type == CXt_WHEN)
+        && (prev->blk_oldcop == cx->blk_oldcop)) {
+     cxix--;
+     cx = prev;
+     if (type == CXt_GIVEN)
+      goto cxt_given;
+     else
+      goto cxt_when;
+    }
+   }
+#endif
+   type  = OP_LEAVE;
+   next  = NULL;
+   /* Bare blocks (that appear as do { ... } blocks, map { ... } blocks or
+    * constant folded blcoks) don't need to save the op to return to anywhere
+    * since 'last' isn't supposed to work inside them. So we climb higher in
+    * the context stack until we reach a context that has a return op (i.e. a
+    * sub, an eval, a format or a real loop), recording how many blocks we
+    * crossed. Then we follow the op_next chain until we get to the leave op
+    * that closes the original block, which we are assured to reach since
+    * everything is static (the blocks we have crossed cannot be evals or
+    * subroutine calls). */
+   for (i = cxix + 1; i <= cur; ++i) {
+    PERL_CONTEXT *cx2 = cxstack + i;
+    switch (CxTYPE(cx2)) {
+     case CXt_BLOCK:
+      ++n;
+      break;
+     case CXt_SUB:
+     case CXt_FORMAT:
+      o = SU_RETOP_SUB(cx2);
+      break;
+     case CXt_EVAL:
+      o = SU_RETOP_EVAL(cx2);
+      break;
+#if SU_HAS_PERL(5, 11, 0)
+     case CXt_LOOP_FOR:
+     case CXt_LOOP_PLAIN:
+     case CXt_LOOP_LAZYSV:
+     case CXt_LOOP_LAZYIV:
+#else
+     case CXt_LOOP:
+#endif
+      o = SU_RETOP_LOOP(cx2);
+      break;
+    }
+    if (o)
+     break;
+   }
+   if (!o)
+    o = PL_op;
+   while (n && o) {
+    /* We may find other enter/leave blocks on our way to the matching leave.
+     * Make sure the depth is incremented/decremented appropriately. */
+    if (o->op_type == OP_ENTER) {
+     ++n;
+    } else if (o->op_type == OP_LEAVE) {
+     --n;
+     if (!n) {
+      next = o->op_next;
+      break;
+     }
+    }
+    o = o->op_next;
+   }
+   break;
+  }
+  case CXt_SUB:
+  case CXt_FORMAT:
+   type = OP_LEAVESUB;
+   next = SU_RETOP_SUB(cx);
+   break;
+  case CXt_EVAL:
+   type = CxTRYBLOCK(cx) ? OP_LEAVETRY : OP_LEAVEEVAL;
+   next = SU_RETOP_EVAL(cx);
+   break;
+#if SU_HAS_PERL(5, 11, 0)
+  case CXt_LOOP_FOR:
+  case CXt_LOOP_PLAIN:
+  case CXt_LOOP_LAZYSV:
+  case CXt_LOOP_LAZYIV:
+#else
+  case CXt_LOOP:
+#endif
+   type = OP_LEAVELOOP;
+   next = SU_RETOP_LOOP(cx);
+   break;
+#if SU_HAS_PERL(5, 10, 0)
+  case CXt_GIVEN:
+cxt_given:
+   type = OP_LEAVEGIVEN;
+   next = SU_RETOP_GIVEN(cx);
+   break;
+  case CXt_WHEN:
+cxt_when:
+#if SU_HAS_PERL(5, 15, 1)
+   type   = OP_LEAVEWHEN;
+#else
+   type   = OP_BREAK;
+   flags |= OPf_SPECIAL;
+#endif
+   next   = NULL;
+   break;
+#endif
+  case CXt_SUBST:
+   croak("%s() can't target a substitution context", which);
+   break;
   default:
+   croak("%s() doesn't know how to leave a %s context",
+          which,                         SU_CXNAME(cxstack + cxix));
    break;
  }
 
- return OPf_WANT_SCALAR;
-}
-#define OP_GIMME_REVERSE(G) su_op_gimme_reverse(G)
+ PL_stack_sp = MY_CXT.yield_storage.savesp;
+#if SU_HAS_PERL(5, 19, 4)
+ {
+  I32 i;
+  SV **sp = PL_stack_sp;
+  for (i = -items + 1; i <= 0; ++i)
+   if (!SvTEMP(sp[i]))
+    sv_2mortal(SvREFCNT_inc(sp[i]));
+ }
 #endif
 
+ if (cxstack_ix > cxix)
+  dounwind(cxix);
+
+ /* Copy the arguments passed to yield() where the leave op expects to find
+  * them. */
+ if (items)
+  Move(PL_stack_sp - items + 1, PL_stack_base + cx->blk_oldsp + 1, items, SV *);
+ PL_stack_sp = PL_stack_base + cx->blk_oldsp + items;
+
+ flags |= OP_GIMME_REVERSE(cx->blk_gimme);
+
+ MY_CXT.yield_storage.leave_op.op_type   = type;
+ MY_CXT.yield_storage.leave_op.op_ppaddr = PL_ppaddr[type];
+ MY_CXT.yield_storage.leave_op.op_flags  = flags;
+ MY_CXT.yield_storage.leave_op.op_next   = next;
+
+ PL_op = (OP *) &(MY_CXT.yield_storage.leave_op);
+ PL_op = PL_op->op_ppaddr(aTHX);
+
+ MY_CXT.yield_storage.proxy_op.op_next = PL_op;
+ PL_op = &(MY_CXT.yield_storage.proxy_op);
+}
+
+/* --- Uplevel ------------------------------------------------------------- */
+
 #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;
@@ -974,6 +1370,14 @@ 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;
 }
 
@@ -981,6 +1385,20 @@ 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 {
@@ -990,33 +1408,101 @@ STATIC void su_uplevel_storage_delete(pTHX_ su_uplevel_ud *sud) {
  }
 }
 
-#define SU_HAS_EXT_MAGIC SU_HAS_PERL(5, 8, 0)
-
-#if SU_HAS_EXT_MAGIC && !SU_HAS_PERL(5, 13, 7)
+STATIC int su_uplevel_goto_static(const OP *o) {
+ for (; o; o = OpSIBLING(o)) {
+  /* goto ops are unops with kids. */
+  if (!(o->op_flags & OPf_KIDS))
+   continue;
 
-STATIC int su_uplevel_restore_free(pTHX_ SV *sv, MAGIC *mg) {
- su_uplevel_storage_delete((su_uplevel_ud *) mg->mg_ptr);
+  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(((const UNOP *) o)->op_first))
+     return 1;
+    break;
+  }
+ }
 
  return 0;
 }
 
-STATIC MGVTBL su_uplevel_restore_vtbl = {
- 0,
- 0,
- 0,
- 0,
- su_uplevel_restore_free
-};
+#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;
+}
 
-#endif /* SU_HAS_EXT_MAGIC && !SU_HAS_PERL(5, 13, 7) */
+#endif /* SU_UPLEVEL_HIJACKS_RUNOPS */
 
-#define su_at_underscore(C) AvARRAY(AvARRAY(CvPADLIST(C))[CvDEPTH(C)])[0]
+#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;
 
+#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));
@@ -1051,8 +1537,10 @@ STATIC void su_uplevel_restore(pTHX_ void *sus_) {
   * 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;
-  CvPADLIST(sud->renamed) = NULL;
+  if (!CvISXSUB(sud->renamed)) {
+   CvDEPTH(sud->renamed)   = 0;
+   CvPADLIST(sud->renamed) = NULL;
+  }
   SvREFCNT_dec(sud->renamed);
  }
 
@@ -1149,20 +1637,15 @@ 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++;
@@ -1191,6 +1674,9 @@ STATIC CV *su_cv_clone(pTHX_ CV *proto, GV *gv) {
 #endif
 
  CvGV_set(cv, gv);
+#if SU_RELEASE && SU_HAS_PERL_EXACT(5, 21, 4)
+ CvNAMED_off(cv);
+#endif
  CvSTASH_set(cv, CvSTASH(proto));
  /* Commit 4c74a7df, publicized with perl 5.13.3, began to add backrefs to
   * stashes. CvSTASH_set() started to do it as well with commit c68d95645
@@ -1200,16 +1686,21 @@ 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);
+  CvPADLIST(cv)    = CvPADLIST(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
@@ -1248,7 +1739,7 @@ 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;
@@ -1330,12 +1821,19 @@ 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;
 
+  /* If pp_entersub() returns a non-null OP, it means that the callback is not
+   * an XSUB. */
+
   sud->callback = MUTABLE_CV(SvREFCNT_inc(callback));
   CvDEPTH(callback)++;
 
@@ -1356,15 +1854,28 @@ STATIC I32 su_uplevel(pTHX_ CV *callback, I32 cxix, I32 args) {
    SvREFCNT_inc_simple_void(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");
+   }
 
-  ret = PL_stack_sp - (PL_stack_base + new_mark);
+   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 */
+  }
+
+  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;
 
@@ -1379,19 +1890,327 @@ 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)) {
+#if SU_HAS_PERL(5, 17, 1)
+   case CXt_LOOP_PLAIN:
+#endif
+   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_normalize_up(pTHX_ I32 cxix) {
+#define su_context_normalize_up(C) su_context_normalize_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)
+     return cxix - 1;
+    break;
+   case CXt_SUBST:
+    if (cx->blk_oldcop && OpSIBLING(cx->blk_oldcop)
+                       && OpSIBLING(cx->blk_oldcop)->op_type == OP_SUBST)
+     return cxix - 1;
+    break;
+  }
+ }
+
+ return cxix;
+}
+
+STATIC I32 su_context_normalize_down(pTHX_ I32 cxix) {
+#define su_context_normalize_down(C) su_context_normalize_down(aTHX_ (C))
+ PERL_CONTEXT *next;
+
+ if (cxix >= cxstack_ix)
+  return cxstack_ix;
+
+ next = cxstack + cxix + 1;
+ if (CxTYPE(next) == CXt_BLOCK) {
+  PERL_CONTEXT *cx = next - 1;
+
+  switch (CxTYPE(cx)) {
+#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 == next->blk_oldcop)
+     return cxix + 1;
+    break;
+   case CXt_SUBST:
+    if (next->blk_oldcop && OpSIBLING(next->blk_oldcop)
+                         && OpSIBLING(next->blk_oldcop)->op_type == OP_SUBST)
+     return cxix + 1;
+    break;
+  }
+ }
+
+ return cxix;
+}
+
+#define su_context_here() su_context_normalize_up(su_context_skip_db(cxstack_ix))
+
+STATIC I32 su_context_gimme(pTHX_ I32 cxix) {
+#define su_context_gimme(C) su_context_gimme(aTHX_ (C))
+ I32 i;
+
+ for (i = cxix; i >= 0; --i) {
+  PERL_CONTEXT *cx = cxstack + i;
+
+  switch (CxTYPE(cx)) {
+   /* gimme is always G_ARRAY for loop contexts. */
+#if SU_HAS_PERL(5, 11, 0)
+   case CXt_LOOP_FOR:
+   case CXt_LOOP_PLAIN:
+   case CXt_LOOP_LAZYSV:
+   case CXt_LOOP_LAZYIV:
+#else
+   case CXt_LOOP:
+#endif
+   case CXt_SUBST: {
+    const COP *cop = cx->blk_oldcop;
+    if (cop && OpSIBLING(cop)) {
+     switch (OpSIBLING(cop)->op_flags & OPf_WANT) {
+      case OPf_WANT_VOID:
+       return G_VOID;
+      case OPf_WANT_SCALAR:
+       return G_SCALAR;
+      case OPf_WANT_LIST:
+       return G_ARRAY;
+      default:
+       break;
+     }
+    }
+    break;
+   }
+   default:
+    return CxGIMME(cx);
+    break;
+  }
+ }
+
+ return G_VOID;
+}
+
 /* --- 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;
@@ -1420,9 +2239,22 @@ STATIC void su_setup(pTHX) {
  MY_CXT.unwind_storage.proxy_op.op_type   = OP_STUB;
  MY_CXT.unwind_storage.proxy_op.op_ppaddr = NULL;
 
+ Zero(&(MY_CXT.yield_storage.leave_op), 1, UNOP);
+ MY_CXT.yield_storage.leave_op.op_type   = OP_STUB;
+ MY_CXT.yield_storage.leave_op.op_ppaddr = NULL;
+
+ Zero(&(MY_CXT.yield_storage.proxy_op), 1, OP);
+ MY_CXT.yield_storage.proxy_op.op_type   = OP_STUB;
+ MY_CXT.yield_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;
@@ -1430,51 +2262,21 @@ 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) {             \
-   SV *csv = ST(B);            \
-   if (!SvOK(csv))             \
-    goto default_cx;           \
-   cxix = SvIV(csv);           \
-   if (cxix < 0)               \
-    cxix = 0;                  \
-   else if (cxix > cxstack_ix) \
-    cxix = cxstack_ix;         \
-  } else {                     \
-default_cx:                    \
-   cxix = cxstack_ix;          \
-   if (PL_DBsub)               \
-    SU_SKIP_DB(cxix);          \
-  }                            \
+#define SU_GET_CONTEXT(A, B, D) \
+ STMT_START {                   \
+  if (items > A) {              \
+   SV *csv = ST(B);             \
+   if (!SvOK(csv))              \
+    goto default_cx;            \
+   cxix = SvIV(csv);            \
+   if (cxix < 0)                \
+    cxix = 0;                   \
+   else if (cxix > cxstack_ix)  \
+    goto default_cx;            \
+  } else {                      \
+default_cx:                     \
+   cxix = (D);                  \
+  }                             \
  } STMT_END
 
 #define SU_GET_LEVEL(A, B) \
@@ -1490,6 +2292,12 @@ default_cx:                    \
   }                        \
  } STMT_END
 
+#if SU_HAS_PERL(5, 10, 0)
+# define SU_INFO_COUNT 11
+#else
+# define SU_INFO_COUNT 10
+#endif
+
 XS(XS_Scope__Upper_unwind); /* prototype to pass -Wmissing-prototypes */
 
 XS(XS_Scope__Upper_unwind) {
@@ -1504,7 +2312,7 @@ XS(XS_Scope__Upper_unwind) {
  PERL_UNUSED_VAR(cv); /* -W */
  PERL_UNUSED_VAR(ax); /* -Wall */
 
- SU_GET_CONTEXT(0, items - 1);
+ SU_GET_CONTEXT(0, items - 1, cxstack_ix);
  do {
   PERL_CONTEXT *cx = cxstack + cxix;
   switch (CxTYPE(cx)) {
@@ -1513,17 +2321,18 @@ XS(XS_Scope__Upper_unwind) {
      continue;
    case CXt_EVAL:
    case CXt_FORMAT:
-    MY_CXT.unwind_storage.cxix  = cxix;
-    MY_CXT.unwind_storage.items = items;
+    MY_CXT.unwind_storage.cxix   = cxix;
+    MY_CXT.unwind_storage.items  = items;
+    MY_CXT.unwind_storage.savesp = PL_stack_sp;
+    if (items > 0) {
+     MY_CXT.unwind_storage.items--;
+     MY_CXT.unwind_storage.savesp--;
+    }
     /* pp_entersub will want to sanitize the stack after returning from there
-     * Screw that, we're insane */
-    if (GIMME_V == G_SCALAR) {
-     MY_CXT.unwind_storage.savesp = PL_stack_sp;
-     /* dXSARGS calls POPMARK, so we need to match PL_markstack_ptr[1] */
+     * Screw that, we're insane!
+     * dXSARGS calls POPMARK, so we need to match PL_markstack_ptr[1] */
+    if (GIMME_V == G_SCALAR)
      PL_stack_sp = PL_stack_base + PL_markstack_ptr[1] + 1;
-    } else {
-     MY_CXT.unwind_storage.savesp = NULL;
-    }
     SAVEDESTRUCTOR_X(su_unwind, NULL);
     return;
    default:
@@ -1533,6 +2342,62 @@ XS(XS_Scope__Upper_unwind) {
  croak("Can't return outside a subroutine");
 }
 
+STATIC const char su_yield_name[] = "yield";
+
+XS(XS_Scope__Upper_yield); /* prototype to pass -Wmissing-prototypes */
+
+XS(XS_Scope__Upper_yield) {
+#ifdef dVAR
+ dVAR; dXSARGS;
+#else
+ dXSARGS;
+#endif
+ dMY_CXT;
+ I32 cxix;
+
+ PERL_UNUSED_VAR(cv); /* -W */
+ PERL_UNUSED_VAR(ax); /* -Wall */
+
+ SU_GET_CONTEXT(0, items - 1, su_context_here());
+ MY_CXT.yield_storage.cxix   = cxix;
+ MY_CXT.yield_storage.items  = items;
+ MY_CXT.yield_storage.savesp = PL_stack_sp;
+ if (items > 0) {
+  MY_CXT.yield_storage.items--;
+  MY_CXT.yield_storage.savesp--;
+ }
+ /* See XS_Scope__Upper_unwind */
+ if (GIMME_V == G_SCALAR)
+  PL_stack_sp = PL_stack_base + PL_markstack_ptr[1] + 1;
+ SAVEDESTRUCTOR_X(su_yield, su_yield_name);
+ return;
+}
+
+STATIC const char su_leave_name[] = "leave";
+
+XS(XS_Scope__Upper_leave); /* prototype to pass -Wmissing-prototypes */
+
+XS(XS_Scope__Upper_leave) {
+#ifdef dVAR
+ dVAR; dXSARGS;
+#else
+ dXSARGS;
+#endif
+ dMY_CXT;
+
+ PERL_UNUSED_VAR(cv); /* -W */
+ PERL_UNUSED_VAR(ax); /* -Wall */
+
+ MY_CXT.yield_storage.cxix   = su_context_here();
+ MY_CXT.yield_storage.items  = items;
+ MY_CXT.yield_storage.savesp = PL_stack_sp;
+ /* See XS_Scope__Upper_unwind */
+ if (GIMME_V == G_SCALAR)
+  PL_stack_sp = PL_stack_base + PL_markstack_ptr[1] + 1;
+ SAVEDESTRUCTOR_X(su_yield, su_leave_name);
+ return;
+}
+
 MODULE = Scope::Upper            PACKAGE = Scope::Upper
 
 PROTOTYPES: ENABLE
@@ -1541,11 +2406,18 @@ 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));
 
  newXSproto("Scope::Upper::unwind", XS_Scope__Upper_unwind, file, NULL);
+ newXSproto("Scope::Upper::yield",  XS_Scope__Upper_yield,  file, NULL);
+ newXSproto("Scope::Upper::leave",  XS_Scope__Upper_leave,  file, NULL);
 
  su_setup();
 }
@@ -1555,11 +2427,22 @@ 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);
 
@@ -1569,10 +2452,9 @@ void
 HERE()
 PROTOTYPE:
 PREINIT:
- I32 cxix = cxstack_ix;
+ I32 cxix;
 PPCODE:
- if (PL_DBsub)
-  SU_SKIP_DB(cxix);
+ cxix = su_context_here();
  EXTEND(SP, 1);
  mPUSHi(cxix);
  XSRETURN(1);
@@ -1583,11 +2465,12 @@ PROTOTYPE: ;$
 PREINIT:
  I32 cxix;
 PPCODE:
- SU_GET_CONTEXT(0, 0);
- if (--cxix < 0)
-  cxix = 0;
- if (PL_DBsub)
-  SU_SKIP_DB(cxix);
+ SU_GET_CONTEXT(0, 0, su_context_here());
+ if (cxix > 0) {
+  --cxix;
+  cxix = su_context_skip_db(cxix);
+  cxix = su_context_normalize_up(cxix);
+ }
  EXTEND(SP, 1);
  mPUSHi(cxix);
  XSRETURN(1);
@@ -1598,7 +2481,7 @@ PROTOTYPE: ;$
 PREINIT:
  I32 cxix;
 PPCODE:
- SU_GET_CONTEXT(0, 0);
+ SU_GET_CONTEXT(0, 0, cxstack_ix);
  EXTEND(SP, 1);
  for (; cxix >= 0; --cxix) {
   PERL_CONTEXT *cx = cxstack + cxix;
@@ -1620,7 +2503,7 @@ PROTOTYPE: ;$
 PREINIT:
  I32 cxix;
 PPCODE:
- SU_GET_CONTEXT(0, 0);
+ SU_GET_CONTEXT(0, 0, cxstack_ix);
  EXTEND(SP, 1);
  for (; cxix >= 0; --cxix) {
   PERL_CONTEXT *cx = cxstack + cxix;
@@ -1641,19 +2524,13 @@ 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_here();
+ while (--level >= 0) {
+  if (cxix <= 0)
+   break;
+  --cxix;
+  cxix = su_context_skip_db(cxix);
+  cxix = su_context_normalize_up(cxix);
  }
  EXTEND(SP, 1);
  mPUSHi(cxix);
@@ -1690,12 +2567,14 @@ PROTOTYPE: ;$
 PREINIT:
  I32 cxix;
 PPCODE:
- SU_GET_CONTEXT(0, 0);
+ SU_GET_CONTEXT(0, 0, cxstack_ix);
  EXTEND(SP, 1);
  while (cxix > 0) {
   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;
@@ -1710,6 +2589,160 @@ PPCODE:
  }
  XSRETURN_UNDEF;
 
+void
+context_info(...)
+PROTOTYPE: ;$
+PREINIT:
+ I32 cxix;
+ const PERL_CONTEXT *cx, *dbcx;
+ COP *cop;
+PPCODE:
+ SU_GET_CONTEXT(0, 0, su_context_skip_db(cxstack_ix));
+ cxix = su_context_normalize_up(cxix);
+ cx   = cxstack + cxix;
+ dbcx = cx;
+ if (PL_DBsub && cxix && (CxTYPE(cx) == CXt_SUB || CxTYPE(cx) == CXt_FORMAT)) {
+  I32 i = su_context_skip_db(cxix - 1) + 1;
+  if (i < cxix && CxTYPE(cxstack + i) == CXt_SUB)
+   cx = cxstack + i;
+ }
+ cop  = cx->blk_oldcop;
+ EXTEND(SP, SU_INFO_COUNT);
+ /* stash (0) */
+ {
+  HV *stash = CopSTASH(cop);
+  if (stash)
+   PUSHs(su_newmortal_pvn(HvNAME(stash), HvNAMELEN(stash)));
+  else
+   PUSHs(&PL_sv_undef);
+ }
+ /* file (1) */
+ PUSHs(su_newmortal_pvn(OutCopFILE(cop), OutCopFILE_len(cop)));
+ /* line (2) */
+ mPUSHi(CopLINE(cop));
+ /* subroutine (3) and has_args (4) */
+ switch (CxTYPE(cx)) {
+  case CXt_SUB:
+  case CXt_FORMAT: {
+   GV *cvgv = CvGV(dbcx->blk_sub.cv);
+   if (cvgv && isGV(cvgv)) {
+    SV *sv = sv_newmortal();
+    gv_efullname3(sv, cvgv, NULL);
+    PUSHs(sv);
+   } else {
+    PUSHs(su_newmortal_pvs("(unknown)"));
+   }
+   if (CxHASARGS(cx))
+    PUSHs(&PL_sv_yes);
+   else
+    PUSHs(&PL_sv_no);
+   break;
+  }
+  case CXt_EVAL:
+   PUSHs(su_newmortal_pvs("(eval)"));
+   mPUSHi(0);
+   break;
+  default:
+   PUSHs(&PL_sv_undef);
+   PUSHs(&PL_sv_undef);
+ }
+ /* gimme (5) */
+ switch (su_context_gimme(cxix)) {
+  case G_ARRAY:
+   PUSHs(&PL_sv_yes);
+   break;
+  case G_SCALAR:
+   PUSHs(&PL_sv_no);
+   break;
+  default: /* G_VOID */
+   PUSHs(&PL_sv_undef);
+   break;
+ }
+ /* eval text (6) and is_require (7) */
+ switch (CxTYPE(cx)) {
+  case CXt_EVAL:
+   if (CxOLD_OP_TYPE(cx) == OP_ENTEREVAL) {
+    /* eval STRING */
+#if SU_HAS_PERL(5, 17, 4)
+    PUSHs(newSVpvn_flags(SvPVX(cx->blk_eval.cur_text),
+                         SvCUR(cx->blk_eval.cur_text)-2,
+                         SvUTF8(cx->blk_eval.cur_text)|SVs_TEMP));
+#else
+    PUSHs(cx->blk_eval.cur_text);
+#endif
+    PUSHs(&PL_sv_no);
+    break;
+   } else if (cx->blk_eval.old_namesv) {
+    /* require */
+    PUSHs(sv_mortalcopy(cx->blk_eval.old_namesv));
+    PUSHs(&PL_sv_yes);
+    break;
+   }
+   /* FALLTHROUGH */
+  default:
+   /* Anything else including eval BLOCK */
+   PUSHs(&PL_sv_undef);
+   PUSHs(&PL_sv_undef);
+   break;
+ }
+ /* hints (8) */
+ mPUSHi(CopHINTS_get(cop));
+ /* warnings (9) */
+ {
+  SV *mask = NULL;
+#if SU_HAS_PERL(5, 9, 4)
+  STRLEN *old_warnings = cop->cop_warnings;
+#else
+  SV *old_warnings = cop->cop_warnings;
+#endif
+  if (old_warnings == pWARN_STD) {
+   if (PL_dowarn & G_WARN_ON)
+    goto context_info_warnings_on;
+   else
+#if SU_HAS_PERL(5, 17, 4)
+    mask = &PL_sv_undef;
+#else
+    goto context_info_warnings_off;
+#endif
+  } else if (old_warnings == pWARN_NONE) {
+context_info_warnings_off:
+   mask = su_newmortal_pvn(WARN_NONEstring, WARNsize);
+  } else if (old_warnings == pWARN_ALL) {
+   HV *bits;
+context_info_warnings_on:
+#if SU_HAS_PERL(5, 8, 7)
+   bits = get_hv("warnings::Bits", 0);
+   if (bits) {
+    SV **bits_all = hv_fetchs(bits, "all", FALSE);
+    if (bits_all)
+     mask = sv_mortalcopy(*bits_all);
+   }
+#endif
+   if (!mask)
+    mask = su_newmortal_pvn(WARN_ALLstring, WARNsize);
+  } else {
+#if SU_HAS_PERL(5, 9, 4)
+   mask = su_newmortal_pvn((char *) (old_warnings + 1), old_warnings[0]);
+#else
+   mask = sv_mortalcopy(old_warnings);
+#endif
+  }
+  PUSHs(mask);
+ }
+#if SU_HAS_PERL(5, 10, 0)
+ /* hints hash (10) */
+ {
+  COPHH *hints_hash = CopHINTHASH_get(cop);
+  if (hints_hash) {
+   SV *rhv = sv_2mortal(newRV_noinc((SV *) cophh_2hv(hints_hash, 0)));
+   PUSHs(rhv);
+  } else {
+   PUSHs(&PL_sv_undef);
+  }
+ }
+#endif
+ XSRETURN(SU_INFO_COUNT);
+
 void
 reap(SV *hook, ...)
 PROTOTYPE: &;$
@@ -1717,7 +2750,8 @@ PREINIT:
  I32 cxix;
  su_ud_reap *ud;
 CODE:
- SU_GET_CONTEXT(1, 1);
+ SU_GET_CONTEXT(1, 1, su_context_skip_db(cxstack_ix));
+ cxix = su_context_normalize_down(cxix);
  Newx(ud, 1, su_ud_reap);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_reap;
@@ -1732,7 +2766,8 @@ PREINIT:
  I32 size;
  su_ud_localize *ud;
 CODE:
- SU_GET_CONTEXT(2, 2);
+ SU_GET_CONTEXT(2, 2, su_context_skip_db(cxstack_ix));
+ cxix = su_context_normalize_down(cxix);
  Newx(ud, 1, su_ud_localize);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
@@ -1749,7 +2784,8 @@ PREINIT:
 CODE:
  if (SvTYPE(sv) >= SVt_PVGV)
   croak("Can't infer the element localization type from a glob and the value");
- SU_GET_CONTEXT(3, 3);
+ SU_GET_CONTEXT(3, 3, su_context_skip_db(cxstack_ix));
+ cxix = su_context_normalize_down(cxix);
  Newx(ud, 1, su_ud_localize);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
@@ -1768,7 +2804,8 @@ PREINIT:
  I32 size;
  su_ud_localize *ud;
 CODE:
- SU_GET_CONTEXT(2, 2);
+ SU_GET_CONTEXT(2, 2, su_context_skip_db(cxstack_ix));
+ cxix = su_context_normalize_down(cxix);
  Newx(ud, 1, su_ud_localize);
  SU_UD_ORIGIN(ud)  = NULL;
  SU_UD_HANDLER(ud) = su_localize;
@@ -1785,7 +2822,7 @@ PPCODE:
   code = SvRV(code);
  if (SvTYPE(code) < SVt_PVCV)
   croak("First argument to uplevel must be a code reference");
- SU_GET_CONTEXT(1, items - 1);
+ SU_GET_CONTEXT(1, items - 1, cxstack_ix);
  do {
   PERL_CONTEXT *cx = cxstack + cxix;
   switch (CxTYPE(cx)) {
@@ -1808,3 +2845,27 @@ 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, su_context_here());
+ 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);