X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=perlio.c;h=94b7c17fcd521f8a2e4b6c8627906806c9d6d884;hb=fe9745bfc279b016730696fd0a6abca4d493be60;hp=62149b05dde097fcae7e463b6aeba68021739c63;hpb=a999f61be32148694ba1c2837b1a303e42fd96b1;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/perlio.c b/perlio.c
index 62149b0..94b7c17 100644
--- a/perlio.c
+++ b/perlio.c
@@ -106,20 +106,25 @@ PerlIO_openn(pTHX_ const char *layers, const char *mode, int fd, int imode, int
 {
  if (narg == 1)
   {
-   char *name = SvPV_nolen(*args);
-   if (*mode == '#')
-    {
-     fd = PerlLIO_open3(name,imode,perm);
-     if (fd >= 0)
-      return PerlIO_fdopen(fd,mode+1);
-    }
-   else if (old)
-    {
-     return PerlIO_reopen(name,mode,old);
-    }
+   if (*args == &PL_sv_undef)
+    return PerlIO_tmpfile();
    else
     {
-     return PerlIO_open(name,mode);
+     char *name = SvPV_nolen(*args);
+     if (*mode == '#')
+      {
+       fd = PerlLIO_open3(name,imode,perm);
+       if (fd >= 0)
+        return PerlIO_fdopen(fd,mode+1);
+      }
+     else if (old)
+      {
+       return PerlIO_reopen(name,mode,old);
+      }
+     else
+      {
+       return PerlIO_open(name,mode);
+      }
     }
   }
  else
@@ -246,6 +251,8 @@ PerlIO_debug(const char *fmt,...)
 PerlIO *_perlio      = NULL;
 #define PERLIO_TABLE_SIZE 64
 
+
+
 PerlIO *
 PerlIO_allocate(pTHX)
 {
@@ -350,8 +357,22 @@ PerlIO_find_layer(pTHX_ const char *name, STRLEN len)
  if ((SSize_t) len <= 0)
   len = strlen(name);
  svp  = hv_fetch(PerlIO_layer_hv,name,len,0);
- if (svp && (sv = *svp) && SvROK(sv))
-  return *svp;
+ if (!svp && PL_subname && PerlIO_layer_av && av_len(PerlIO_layer_av)+1 >= 2)
+  {
+   SV *pkgsv  = newSVpvn("PerlIO",6);
+   SV *layer  = newSVpvn(name,len);
+   ENTER;
+   /* The two SVs are magically freed by load_module */
+   Perl_load_module(aTHX_ 0, pkgsv, Nullsv, layer, Nullsv);
+   LEAVE;
+   /* Say this is lvalue so we get an 'undef' if still not there */
+   svp  = hv_fetch(PerlIO_layer_hv,name,len,1);
+  }
+ if (svp && (sv = *svp))
+  {
+   if (SvROK(sv))
+    return *svp;
+  }
  return NULL;
 }
 
@@ -439,21 +460,110 @@ XS(XS_io_MODIFY_SCALAR_ATTRIBUTES)
  XSRETURN(count);
 }
 
-void
-PerlIO_define_layer(pTHX_ PerlIO_funcs *tab)
+SV *
+PerlIO_tab_sv(pTHX_ PerlIO_funcs *tab)
 {
  HV *stash = gv_stashpv("perlio::Layer", TRUE);
  SV *sv = sv_bless(newRV_noinc(newSViv(PTR2IV(tab))),stash);
+ return sv;
+}
+
+void
+PerlIO_define_layer(pTHX_ PerlIO_funcs *tab)
+{
  if (!PerlIO_layer_hv)
   {
    PerlIO_layer_hv = get_hv("open::layers",GV_ADD|GV_ADDMULTI);
   }
- hv_store(PerlIO_layer_hv,tab->name,strlen(tab->name),sv,0);
+ hv_store(PerlIO_layer_hv,tab->name,strlen(tab->name),PerlIO_tab_sv(aTHX_ tab),0);
  PerlIO_debug("define %s %p\n",tab->name,tab);
 }
 
+int
+PerlIO_parse_layers(pTHX_ AV *av, const char *names)
+{
+ if (names)
+  {
+   const char *s = names;
+   while (*s)
+    {
+     while (isSPACE(*s) || *s == ':')
+      s++;
+     if (*s)
+      {
+       STRLEN llen = 0;
+       const char *e = s;
+       const char *as = Nullch;
+       STRLEN alen = 0;
+       if (!isIDFIRST(*s))
+        {
+         /* Message is consistent with how attribute lists are passed.
+            Even though this means "foo : : bar" is seen as an invalid separator
+            character.  */
+         char q = ((*s == '\'') ? '"' : '\'');
+         Perl_warn(aTHX_ "perlio: invalid separator character %c%c%c in layer specification list", q, *s, q);
+         return -1;
+        }
+       do
+        {
+         e++;
+        } while (isALNUM(*e));
+       llen = e-s;
+       if (*e == '(')
+        {
+         int nesting = 1;
+         as = ++e;
+         while (nesting)
+          {
+           switch (*e++)
+            {
+             case ')':
+              if (--nesting == 0)
+               alen = (e-1)-as;
+              break;
+             case '(':
+              ++nesting;
+              break;
+             case '\\':
+              /* It's a nul terminated string, not allowed to \ the terminating null.
+                 Anything other character is passed over.  */
+              if (*e++)
+               {
+                break;
+               }
+              /* Drop through */
+             case '\0':
+              e--;
+              Perl_warn(aTHX_ "perlio: argument list not closed for layer \"%.*s\"",(int)(e - s),s);
+              return -1;
+             default:
+              /* boring.  */
+              break;
+            }
+          }
+        }
+       if (e > s)
+        {
+         SV *layer = PerlIO_find_layer(aTHX_ s,llen);
+         if (layer)
+          {
+           av_push(av,SvREFCNT_inc(layer));
+           av_push(av,(as) ? newSVpvn(as,alen) : &PL_sv_undef);
+          }
+         else {
+          Perl_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(int)llen,s);
+	  return -1;
+	 }
+        }
+       s = e;
+      }
+    }
+  }
+ return 0;
+}
+
 void
-PerlIO_default_buffer(pTHX)
+PerlIO_default_buffer(pTHX_ AV *av)
 {
  PerlIO_funcs *tab = &PerlIO_perlio;
  if (O_BINARY != O_TEXT)
@@ -468,21 +578,39 @@ PerlIO_default_buffer(pTHX)
     }
   }
  PerlIO_debug("Pushing %s\n",tab->name);
- av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(aTHX_ tab->name,0)));
+ av_push(av,SvREFCNT_inc(PerlIO_find_layer(aTHX_ tab->name,0)));
+ av_push(av,&PL_sv_undef);
 }
 
-
+SV *
+PerlIO_arg_fetch(pTHX_ AV *av,IV n)
+{
+ SV **svp = av_fetch(av,n,FALSE);
+ return (svp) ? *svp : Nullsv;
+}
 
 PerlIO_funcs *
-PerlIO_default_layer(pTHX_ I32 n)
+PerlIO_layer_fetch(pTHX_ AV *av,IV n,PerlIO_funcs *def)
 {
- SV **svp;
+ SV **svp = av_fetch(av,n,FALSE);
  SV *layer;
- PerlIO_funcs *tab = &PerlIO_stdio;
- int len;
+ if (svp && (layer = *svp) && SvROK(layer) && SvIOK((layer = SvRV(layer))))
+  {
+   /* PerlIO_debug("Layer %d is %s\n",n/2,tab->name); */
+   return INT2PTR(PerlIO_funcs *, SvIV(layer));
+  }
+ if (!def)
+  Perl_croak(aTHX_ "panic:PerlIO layer array corrupt");
+ return def;
+}
+
+AV *
+PerlIO_default_layers(pTHX)
+{
+ IV len;
  if (!PerlIO_layer_av)
   {
-   const char *s  = PerlEnv_getenv("PERLIO");
+   const char *s  = (PL_tainting) ? Nullch : PerlEnv_getenv("PERLIO");
    PerlIO_layer_av = get_av("open::layers",GV_ADD|GV_ADDMULTI);
    newXS("perlio::import",XS_perlio_import,__FILE__);
    newXS("perlio::unimport",XS_perlio_unimport,__FILE__);
@@ -500,67 +628,44 @@ PerlIO_default_layer(pTHX_ I32 n)
    PerlIO_define_layer(aTHX_ &PerlIO_utf8);
    PerlIO_define_layer(aTHX_ &PerlIO_byte);
    av_push(PerlIO_layer_av,SvREFCNT_inc(PerlIO_find_layer(aTHX_ PerlIO_unix.name,0)));
+   av_push(PerlIO_layer_av,&PL_sv_undef);
    if (s)
     {
-     IV buffered = 0;
-     while (*s)
-      {
-       while (*s && isSPACE((unsigned char)*s))
-        s++;
-       if (*s)
-        {
-         const char *e = s;
-         SV *layer;
-         while (*e && !isSPACE((unsigned char)*e))
-          e++;
-         if (*s == ':')
-          s++;
-         layer = PerlIO_find_layer(aTHX_ s,e-s);
-         if (layer)
-          {
-           PerlIO_funcs *tab = INT2PTR(PerlIO_funcs *, SvIV(SvRV(layer)));
-           if ((tab->kind & PERLIO_K_DUMMY) && (tab->kind & PERLIO_K_BUFFERED))
-            {
-             if (!buffered)
-              PerlIO_default_buffer(aTHX);
-            }
-           PerlIO_debug("Pushing %.*s\n",(e-s),s);
-           av_push(PerlIO_layer_av,SvREFCNT_inc(layer));
-           buffered |= (tab->kind & PERLIO_K_BUFFERED);
-          }
-         else
-          Perl_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(e-s),s);
-         s = e;
-        }
-      }
+     PerlIO_parse_layers(aTHX_ PerlIO_layer_av,s);
+    }
+   else
+    {
+     PerlIO_default_buffer(aTHX_ PerlIO_layer_av);
     }
   }
- len  = av_len(PerlIO_layer_av);
- if (len < 1)
+ len  = av_len(PerlIO_layer_av)+1;
+ if (len < 2)
   {
-   PerlIO_default_buffer(aTHX);
+   PerlIO_default_buffer(aTHX_ PerlIO_layer_av);
    len  = av_len(PerlIO_layer_av);
   }
+ return PerlIO_layer_av;
+}
+
+
+PerlIO_funcs *
+PerlIO_default_layer(pTHX_ I32 n)
+{
+ AV *av = PerlIO_default_layers(aTHX);
+ n *= 2;
  if (n < 0)
-  n += len+1;
- svp = av_fetch(PerlIO_layer_av,n,0);
- if (svp && (layer = *svp) && SvROK(layer) && SvIOK((layer = SvRV(layer))))
-  {
-   tab = INT2PTR(PerlIO_funcs *, SvIV(layer));
-  }
- /* PerlIO_debug("Layer %d is %s\n",n,tab->name); */
- return tab;
+  n += av_len(PerlIO_layer_av)+1;
+ return PerlIO_layer_fetch(aTHX_ av,n, &PerlIO_stdio);
 }
 
 #define PerlIO_default_top() PerlIO_default_layer(aTHX_ -1)
 #define PerlIO_default_btm() PerlIO_default_layer(aTHX_ 0)
 
 void
-PerlIO_stdstreams()
+PerlIO_stdstreams(pTHX)
 {
  if (!_perlio)
   {
-   dTHX;
    PerlIO_allocate(aTHX);
    PerlIO_fdopen(0,"Ir" PERLIO_STDTEXT);
    PerlIO_fdopen(1,"Iw" PERLIO_STDTEXT);
@@ -569,7 +674,7 @@ PerlIO_stdstreams()
 }
 
 PerlIO *
-PerlIO_push(pTHX_ PerlIO *f,PerlIO_funcs *tab,const char *mode,const char *arg,STRLEN len)
+PerlIO_push(pTHX_ PerlIO *f,PerlIO_funcs *tab,const char *mode,SV *arg)
 {
  PerlIOl *l = NULL;
  l = PerlMemShared_calloc(tab->size,sizeof(char));
@@ -579,9 +684,9 @@ PerlIO_push(pTHX_ PerlIO *f,PerlIO_funcs *tab,const char *mode,const char *arg,S
    l->next = *f;
    l->tab  = tab;
    *f      = l;
-   PerlIO_debug("PerlIO_push f=%p %s %s '%.*s'\n",
-                 f,tab->name,(mode) ? mode : "(Null)",(int) len,arg);
-   if ((*l->tab->Pushed)(f,mode,arg,len) != 0)
+   PerlIO_debug("PerlIO_push f=%p %s %s %p\n",f,tab->name,
+                 (mode) ? mode : "(Null)",arg);
+   if ((*l->tab->Pushed)(f,mode,arg) != 0)
     {
      PerlIO_pop(aTHX_ f);
      return NULL;
@@ -591,7 +696,7 @@ PerlIO_push(pTHX_ PerlIO *f,PerlIO_funcs *tab,const char *mode,const char *arg,S
 }
 
 IV
-PerlIOPop_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOPop_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  dTHX;
  PerlIO_pop(aTHX_ f);
@@ -605,7 +710,7 @@ PerlIOPop_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
 }
 
 IV
-PerlIORaw_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIORaw_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  /* Remove the dummy layer */
  dTHX;
@@ -624,7 +729,7 @@ PerlIORaw_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
      else
       {
        /* Nothing bellow - push unix on top then remove it */
-       if (PerlIO_push(aTHX_ f,PerlIO_default_btm(),mode,arg,len))
+       if (PerlIO_push(aTHX_ f,PerlIO_default_btm(),mode,arg))
         {
          PerlIO_pop(aTHX_ PerlIONext(f));
         }
@@ -638,92 +743,42 @@ PerlIORaw_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
 }
 
 int
-PerlIO_apply_layers(pTHX_ PerlIO *f, const char *mode, const char *names)
+PerlIO_apply_layera(pTHX_ PerlIO *f, const char *mode, AV *layers, IV n)
 {
- if (names)
+ IV max = av_len(layers)+1;
+ int code = 0;
+ while (n < max)
   {
-   const char *s = names;
-   while (*s)
+   PerlIO_funcs *tab = PerlIO_layer_fetch(aTHX_ layers,n,NULL);
+   if (tab)
     {
-     while (isSPACE(*s) || *s == ':')
-      s++;
-     if (*s)
+     if (!PerlIO_push(aTHX_ f,tab,mode,PerlIOArg))
       {
-       STRLEN llen = 0;
-       const char *e = s;
-       const char *as = Nullch;
-       STRLEN alen = 0;
-       if (!isIDFIRST(*s))
-        {
-         /* Message is consistent with how attribute lists are passed.
-            Even though this means "foo : : bar" is seen as an invalid separator
-            character.  */
-         char q = ((*s == '\'') ? '"' : '\'');
-         Perl_warn(aTHX_ "perlio: invalid separator character %c%c%c in layer specification list", q, *s, q);
-         return -1;
-        }
-       do
-        {
-         e++;
-        } while (isALNUM(*e));
-       llen = e-s;
-       if (*e == '(')
-        {
-         int nesting = 1;
-         as = ++e;
-         while (nesting)
-          {
-           switch (*e++)
-            {
-             case ')':
-              if (--nesting == 0)
-               alen = (e-1)-as;
-              break;
-             case '(':
-              ++nesting;
-              break;
-             case '\\':
-              /* It's a nul terminated string, not allowed to \ the terminating null.
-                 Anything other character is passed over.  */
-              if (*e++)
-               {
-                break;
-               }
-              /* Drop through */
-             case '\0':
-              e--;
-              Perl_warn(aTHX_ "perlio: argument list not closed for layer \"%.*s\"",(int)(e - s),s);
-              return -1;
-             default:
-              /* boring.  */
-              break;
-            }
-          }
-        }
-       if (e > s)
-        {
-         SV *layer = PerlIO_find_layer(aTHX_ s,llen);
-         if (layer)
-          {
-           PerlIO_funcs *tab = INT2PTR(PerlIO_funcs *, SvIV(SvRV(layer)));
-           if (tab)
-            {
-             if (!PerlIO_push(aTHX_ f,tab,mode,as,alen))
-              return -1;
-            }
-          }
-         else {
-          Perl_warn(aTHX_ "perlio: unknown layer \"%.*s\"",(int)llen,s);
-	  return -1;
-	 }
-        }
-       s = e;
+       code = -1;
+       break;
       }
     }
+   n += 2;
   }
- return 0;
+ return code;
 }
 
+int
+PerlIO_apply_layers(pTHX_ PerlIO *f, const char *mode, const char *names)
+{
+ int code = 0;
+ if (names)
+  {
+   AV *layers = newAV();
+   code = PerlIO_parse_layers(aTHX_ layers,names);
+   if (code == 0)
+    {
+     code = PerlIO_apply_layera(aTHX_ f, mode, layers, 0);
+    }
+   SvREFCNT_dec((SV *) layers);
+  }
+ return code;
+}
 
 
 /*--------------------------------------------------------------------------------------*/
@@ -779,10 +834,14 @@ int
 PerlIO_close(PerlIO *f)
 {
  dTHX;
- int code = (*PerlIOBase(f)->tab->Close)(f);
- while (*f)
+ int code = -1;
+ if (f && *f)
   {
-   PerlIO_pop(aTHX_ f);
+   code = (*PerlIOBase(f)->tab->Close)(f);
+   while (*f)
+    {
+     PerlIO_pop(aTHX_ f);
+    }
   }
  return code;
 }
@@ -794,26 +853,168 @@ PerlIO_fileno(PerlIO *f)
  return (*PerlIOBase(f)->tab->Fileno)(f);
 }
 
-PerlIO_funcs *
-PerlIO_top_layer(pTHX_ const char *layers)
+static const char *
+PerlIO_context_layers(pTHX_ const char *mode)
 {
- /* FIXME !!! */
- return PerlIO_default_top();
+ const char *type = NULL;
+ /* Need to supply default layer info from open.pm */
+ if (PL_curcop)
+  {
+   SV *layers = PL_curcop->cop_io;
+   if (layers)
+    {
+     STRLEN len;
+     type = SvPV(layers,len);
+     if (type && mode[0] != 'r')
+      {
+       /* Skip to write part */
+       const char *s = strchr(type,0);
+       if (s && (s-type) < len)
+        {
+         type = s+1;
+        }
+      }
+    }
+  }
+ return type;
+}
+
+AV *
+PerlIO_resolve_layers(pTHX_ const char *layers,const char *mode,int narg, SV **args)
+{
+ AV *def = PerlIO_default_layers(aTHX);
+ int incdef = 1;
+ if (!_perlio)
+  PerlIO_stdstreams(aTHX);
+ if (narg)
+  {
+   if (SvROK(*args))
+    {
+     if (sv_isobject(*args))
+      {
+       SV *handler = PerlIO_find_layer(aTHX_ "object",6);
+       if (handler)
+        {
+         def    = newAV();
+         av_push(def,handler);
+         av_push(def,&PL_sv_undef);
+         incdef = 0;
+        }
+      }
+     else
+      {
+       if (SvTYPE(SvRV(*args)) < SVt_PVAV)
+        {
+         SV *handler = PerlIO_find_layer(aTHX_ "Scalar",6);
+         if (handler)
+          {
+           def    = newAV();
+           av_push(def,handler);
+           av_push(def,&PL_sv_undef);
+           incdef = 0;
+          }
+        }
+       else
+        {
+         Perl_croak(aTHX_ "Unsupported reference arg to open()");
+        }
+      }
+    }
+  }
+ if (!layers)
+  layers = PerlIO_context_layers(aTHX_ mode);
+ if (layers && *layers)
+  {
+   AV *av;
+   if (incdef)
+    {
+     IV n = av_len(def)+1;
+     av = newAV();
+     while (n-- > 0)
+      {
+       SV **svp = av_fetch(def,n,0);
+       av_store(av,n,(svp) ? SvREFCNT_inc(*svp) : &PL_sv_undef);
+      }
+    }
+   else
+    {
+     av = def;
+    }
+   PerlIO_parse_layers(aTHX_ av,layers);
+   return av;
+  }
+ else
+  {
+   if (incdef)
+    SvREFCNT_inc(def);
+   return def;
+  }
 }
 
 PerlIO *
 PerlIO_openn(pTHX_ const char *layers, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
 {
- PerlIO_funcs *tab = (f && *f) ? PerlIOBase(f)->tab : PerlIO_top_layer(aTHX_ layers);
- if (!_perlio)
-  PerlIO_stdstreams();
- PerlIO_debug("openn(%s,'%s','%s',%d,%x,%o,%p,%d,%p)\n",
-              tab->name,layers,mode,fd,imode,perm,f,narg,args);
- f = (*tab->Open)(aTHX_ tab,mode,fd,imode,perm,f,narg,args);
- if (f)
+ if (!f && narg == 1 && *args == &PL_sv_undef)
   {
-   if (layers && *layers)
-    PerlIO_apply_layers(aTHX_ f,mode,layers);
+   if ((f = PerlIO_tmpfile()))
+    {
+     if (!layers)
+      layers = PerlIO_context_layers(aTHX_ mode);
+     if (layers && *layers)
+      PerlIO_apply_layers(aTHX_ f,mode,layers);
+    }
+  }
+ else
+  {
+   AV *layera;
+   IV n;
+   PerlIO_funcs *tab;
+   if (f && *f)
+    {
+     /* This is "reopen" - it is not tested as perl does not use it yet */
+     PerlIOl *l = *f;
+     layera = newAV();
+     while (l)
+      {
+       SV *arg = (l->tab->Getarg) ? (*l->tab->Getarg)(&l) : &PL_sv_undef;
+       av_unshift(layera,2);
+       av_store(layera,0,PerlIO_tab_sv(aTHX_ l->tab));
+       av_store(layera,1,arg);
+       l = *PerlIONext(&l);
+      }
+    }
+   else
+    {
+     layera = PerlIO_resolve_layers(aTHX_ layers, mode, narg, args);
+    }
+   n = av_len(layera)-1;
+   while (n >= 0)
+    {
+     PerlIO_funcs *t = PerlIO_layer_fetch(aTHX_ layera,n,NULL);
+     if (t && t->Open)
+      {
+       tab = t;
+       break;
+      }
+     n -= 2;
+    }
+   if (tab)
+    {
+     PerlIO_debug("openn(%s,'%s','%s',%d,%x,%o,%p,%d,%p)\n",
+                  tab->name,layers,mode,fd,imode,perm,f,narg,args);
+     f = (*tab->Open)(aTHX_ tab, layera, n, mode,fd,imode,perm,f,narg,args);
+     if (f)
+      {
+       if (n+2 < av_len(layera)+1)
+        {
+         if (PerlIO_apply_layera(aTHX_ f, mode, layera, n+2) != 0)
+          {
+           f = NULL;
+          }
+        }
+      }
+    }
+   SvREFCNT_dec(layera);
   }
  return f;
 }
@@ -1065,7 +1266,7 @@ PerlIO_set_ptrcnt(PerlIO *f, STDCHAR *ptr, int cnt)
 /* utf8 and raw dummy layers */
 
 IV
-PerlIOUtf8_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOUtf8_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  if (PerlIONext(f))
   {
@@ -1081,28 +1282,10 @@ PerlIOUtf8_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
  return -1;
 }
 
-PerlIO *
-PerlIOUtf8_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, int perm, PerlIO *old, int narg, SV **args)
-{
- PerlIO_funcs *tab = PerlIO_default_layer(aTHX_ -2);
- PerlIO *f = (*tab->Open)(aTHX_ tab,mode,fd,imode,perm,old,narg,args);
- if (f)
-  {
-   PerlIOl *l = PerlIOBase(f);
-   if (tab->kind & PERLIO_K_UTF8)
-    l->flags |= PERLIO_F_UTF8;
-   else
-    l->flags &= ~PERLIO_F_UTF8;
- }
- return f;
-}
-
 PerlIO_funcs PerlIO_utf8 = {
  "utf8",
  sizeof(PerlIOl),
  PERLIO_K_DUMMY|PERLIO_F_UTF8,
- NULL,
- PerlIOUtf8_open,
  PerlIOUtf8_pushed,
  NULL,
  NULL,
@@ -1111,6 +1294,9 @@ PerlIO_funcs PerlIO_utf8 = {
  NULL,
  NULL,
  NULL,
+ NULL,
+ NULL,
+ NULL,
  NULL, /* flush */
  NULL, /* fill */
  NULL,
@@ -1128,8 +1314,6 @@ PerlIO_funcs PerlIO_byte = {
  "bytes",
  sizeof(PerlIOl),
  PERLIO_K_DUMMY,
- NULL,
- PerlIOUtf8_open,
  PerlIOUtf8_pushed,
  NULL,
  NULL,
@@ -1138,6 +1322,9 @@ PerlIO_funcs PerlIO_byte = {
  NULL,
  NULL,
  NULL,
+ NULL,
+ NULL,
+ NULL,
  NULL, /* flush */
  NULL, /* fill */
  NULL,
@@ -1152,20 +1339,21 @@ PerlIO_funcs PerlIO_byte = {
 };
 
 PerlIO *
-PerlIORaw_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, int perm, PerlIO *old, int narg, SV **args)
+PerlIORaw_open(pTHX_ PerlIO_funcs *self,  AV *layers, IV n,const char *mode, int fd, int imode, int perm, PerlIO *old, int narg, SV **args)
 {
  PerlIO_funcs *tab = PerlIO_default_btm();
- return (*tab->Open)(aTHX_ tab,mode,fd,imode,perm,old,narg,args);
+ return (*tab->Open)(aTHX_ tab,layers,n-2,mode,fd,imode,perm,old,narg,args);
 }
 
 PerlIO_funcs PerlIO_raw = {
  "raw",
  sizeof(PerlIOl),
  PERLIO_K_DUMMY,
- NULL,
- PerlIORaw_open,
  PerlIORaw_pushed,
  PerlIOBase_popped,
+ PerlIORaw_open,
+ NULL,
+ NULL,
  NULL,
  NULL,
  NULL,
@@ -1230,7 +1418,7 @@ PerlIO_modestr(PerlIO *f,char *buf)
 }
 
 IV
-PerlIOBase_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOBase_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  PerlIOl *l = PerlIOBase(f);
  const char *omode = mode;
@@ -1304,12 +1492,43 @@ PerlIOBase_unread(PerlIO *f, const void *vbuf, Size_t count)
  dTHX;
  Off_t old = PerlIO_tell(f);
  SSize_t done;
- PerlIO_push(aTHX_ f,&PerlIO_pending,"r",Nullch,0);
+ PerlIO_push(aTHX_ f,&PerlIO_pending,"r",Nullsv);
  done = PerlIOBuf_unread(f,vbuf,count);
  PerlIOSelf(f,PerlIOBuf)->posn = old - done;
  return done;
 }
 
+SSize_t
+PerlIOBase_read(PerlIO *f, void *vbuf, Size_t count)
+{
+ STDCHAR *buf  = (STDCHAR *) vbuf;
+ if (f)
+  {
+   if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
+    return 0;
+   while (count > 0)
+    {
+     SSize_t avail = PerlIO_get_cnt(f);
+     SSize_t take  = (count < avail) ? count : avail;
+     if (take > 0)
+      {
+       STDCHAR *ptr = PerlIO_get_ptr(f);
+       Copy(ptr,buf,take,STDCHAR);
+       PerlIO_set_ptrcnt(f,ptr+take,(avail -= take));
+       count   -= take;
+       buf     += take;
+      }
+     if (count > 0  && avail <= 0)
+      {
+       if (PerlIO_fill(f) != 0)
+        break;
+      }
+    }
+   return (buf - (STDCHAR *) vbuf);
+  }
+ return 0;
+}
+
 IV
 PerlIOBase_noop_ok(PerlIO *f)
 {
@@ -1329,7 +1548,7 @@ PerlIOBase_close(PerlIO *f)
  PerlIO *n = PerlIONext(f);
  if (PerlIO_flush(f) != 0)
   code = -1;
- if (n && (*PerlIOBase(n)->tab->Close)(n) != 0)
+ if (n && *n && (*PerlIOBase(n)->tab->Close)(n) != 0)
   code = -1;
  PerlIOBase(f)->flags &= ~(PERLIO_F_CANREAD|PERLIO_F_CANWRITE|PERLIO_F_OPEN);
  return code;
@@ -1370,7 +1589,10 @@ PerlIOBase_clearerr(PerlIO *f)
 void
 PerlIOBase_setlinebuf(PerlIO *f)
 {
-
+ if (f)
+  {
+   PerlIOBase(f)->flags |= PERLIO_F_LINEBUF;
+  }
 }
 
 /*--------------------------------------------------------------------------------------*/
@@ -1449,9 +1671,9 @@ PerlIOUnix_fileno(PerlIO *f)
 }
 
 IV
-PerlIOUnix_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOUnix_pushed(PerlIO *f, const char *mode, SV *arg)
 {
- IV code = PerlIOBase_pushed(f,mode,arg,len);
+ IV code = PerlIOBase_pushed(f,mode,arg);
  if (*PerlIONext(f))
   {
    PerlIOUnix *s = PerlIOSelf(f,PerlIOUnix);
@@ -1463,27 +1685,7 @@ PerlIOUnix_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
 }
 
 PerlIO *
-PerlIOUnix_fdopen(PerlIO_funcs *self, int fd,const char *mode)
-{
- dTHX;
- PerlIO *f = NULL;
- if (*mode == 'I')
-  mode++;
- if (fd >= 0)
-  {
-   int oflags = PerlIOUnix_oflags(mode);
-   if (oflags != -1)
-    {
-     PerlIOUnix *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),self,mode,Nullch,0),PerlIOUnix);
-     s->fd     = fd;
-     s->oflags = oflags;
-    }
-  }
- return f;
-}
-
-PerlIO *
-PerlIOUnix_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
+PerlIOUnix_open(pTHX_ PerlIO_funcs *self, AV *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
 {
  if (f)
   {
@@ -1513,7 +1715,7 @@ PerlIOUnix_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, i
    if (!f)
     {
      f = PerlIO_allocate(aTHX);
-     s = PerlIOSelf(PerlIO_push(aTHX_ f,self,mode,Nullch,0),PerlIOUnix);
+     s = PerlIOSelf(PerlIO_push(aTHX_ f,self,mode,PerlIOArg),PerlIOUnix);
     }
    else
     s = PerlIOSelf(f,PerlIOUnix);
@@ -1615,10 +1817,11 @@ PerlIO_funcs PerlIO_unix = {
  "unix",
  sizeof(PerlIOUnix),
  PERLIO_K_RAW,
- PerlIOUnix_fileno,
- PerlIOUnix_open,
  PerlIOUnix_pushed,
  PerlIOBase_noop_ok,
+ PerlIOUnix_open,
+ NULL,
+ PerlIOUnix_fileno,
  PerlIOUnix_read,
  PerlIOBase_unread,
  PerlIOUnix_write,
@@ -1670,18 +1873,9 @@ PerlIOStdio_mode(const char *mode,char *tmode)
  return ret;
 }
 
-PerlIO *
-PerlIOStdio_fdopen(PerlIO_funcs *self, int fd,const char *mode)
-{
- dTHX;
- PerlIO *f = NULL;
- int init = 0;
- char tmode[8];
-}
-
 /* This isn't used yet ... */
 IV
-PerlIOStdio_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOStdio_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  dTHX;
  if (*PerlIONext(f))
@@ -1694,7 +1888,7 @@ PerlIOStdio_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
    else
     return -1;
   }
- return PerlIOBase_pushed(f,mode,arg,len);
+ return PerlIOBase_pushed(f,mode,arg);
 }
 
 #undef PerlIO_importFILE
@@ -1705,14 +1899,14 @@ PerlIO_importFILE(FILE *stdio, int fl)
  PerlIO *f = NULL;
  if (stdio)
   {
-   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),&PerlIO_stdio,"r+",Nullch,0),PerlIOStdio);
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),&PerlIO_stdio,"r+",Nullsv),PerlIOStdio);
    s->stdio  = stdio;
   }
  return f;
 }
 
 PerlIO *
-PerlIOStdio_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
+PerlIOStdio_open(pTHX_ PerlIO_funcs *self, AV *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
 {
  char tmode[8];
  if (f)
@@ -1741,7 +1935,7 @@ PerlIOStdio_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode,
        if (stdio)
         {
          PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)), self,
-                                     (mode = PerlIOStdio_mode(mode,tmode)),Nullch,0),
+                                     (mode = PerlIOStdio_mode(mode,tmode)),PerlIOArg),
                                      PerlIOStdio);
          s->stdio  = stdio;
         }
@@ -1778,7 +1972,7 @@ PerlIOStdio_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode,
       }
      if (stdio)
       {
-       PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),self,mode,Nullch,0),PerlIOStdio);
+       PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),self,mode,PerlIOArg),PerlIOStdio);
        s->stdio  = stdio;
        return f;
       }
@@ -2025,10 +2219,11 @@ PerlIO_funcs PerlIO_stdio = {
  "stdio",
  sizeof(PerlIOStdio),
  PERLIO_K_BUFFERED,
- PerlIOStdio_fileno,
- PerlIOStdio_open,
  PerlIOBase_pushed,
  PerlIOBase_noop_ok,
+ PerlIOStdio_open,
+ NULL,
+ PerlIOStdio_fileno,
  PerlIOStdio_read,
  PerlIOStdio_unread,
  PerlIOStdio_write,
@@ -2073,7 +2268,7 @@ PerlIO_exportFILE(PerlIO *f, int fl)
  if (stdio)
   {
    dTHX;
-   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ f,&PerlIO_stdio,"r+",Nullch,0),PerlIOStdio);
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ f,&PerlIO_stdio,"r+",Nullsv),PerlIOStdio);
    s->stdio  = stdio;
   }
  return stdio;
@@ -2106,11 +2301,12 @@ PerlIO_releaseFILE(PerlIO *p, FILE *f)
 /* perlio buffer layer */
 
 IV
-PerlIOBuf_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
+PerlIOBuf_pushed(PerlIO *f, const char *mode, SV *arg)
 {
  PerlIOBuf *b = PerlIOSelf(f,PerlIOBuf);
  int fd  = PerlIO_fileno(f);
  Off_t posn;
+ dTHX;
  if (fd >= 0 && PerlLIO_isatty(fd))
   {
    PerlIOBase(f)->flags |= PERLIO_F_LINEBUF;
@@ -2120,35 +2316,35 @@ PerlIOBuf_pushed(PerlIO *f, const char *mode, const char *arg, STRLEN len)
   {
    b->posn = posn;
   }
- return PerlIOBase_pushed(f,mode,arg,len);
+ return PerlIOBase_pushed(f,mode,arg);
 }
 
 PerlIO *
-PerlIOBuf_open(pTHX_ PerlIO_funcs *self, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
+PerlIOBuf_open(pTHX_ PerlIO_funcs *self, AV *layers, IV n, const char *mode, int fd, int imode, int perm, PerlIO *f, int narg, SV **args)
 {
  if (f)
   {
    PerlIO *next = PerlIONext(f);
-   PerlIO_funcs *tab = PerlIOBase(next)->tab;
-   next = (*tab->Open)(aTHX_ tab,mode,fd,imode,perm,next,narg,args);
-   if (!next || (*PerlIOBase(f)->tab->Pushed)(f,mode,Nullch,0) != 0)
+   PerlIO_funcs *tab = PerlIO_layer_fetch(aTHX_ layers, n-2, PerlIOBase(next)->tab);
+   next = (*tab->Open)(aTHX_ tab, layers, n-2, mode,fd,imode,perm,next,narg,args);
+   if (!next || (*PerlIOBase(f)->tab->Pushed)(f,mode,PerlIOArg) != 0)
     {
      return NULL;
     }
   }
  else
   {
-   PerlIO_funcs *tab = PerlIO_default_btm();
+   PerlIO_funcs *tab = PerlIO_layer_fetch(aTHX_ layers, n-2, PerlIO_default_btm());
    int init = 0;
    if (*mode == 'I')
     {
      init = 1;
      mode++;
     }
-   f = (*tab->Open)(aTHX_ tab,mode,fd,imode,perm,NULL,narg,args);
+   f = (*tab->Open)(aTHX_ tab, layers, n-2, mode,fd,imode,perm,NULL,narg,args);
    if (f)
     {
-     PerlIOBuf *b = PerlIOSelf(PerlIO_push(aTHX_ f,self,mode,Nullch,0),PerlIOBuf);
+     PerlIOBuf *b = PerlIOSelf(PerlIO_push(aTHX_ f,self,mode,PerlIOArg),PerlIOBuf);
      fd = PerlIO_fileno(f);
 #if O_BINARY != O_TEXT
      /* do something about failing setmode()? --jhi */
@@ -2287,32 +2483,11 @@ SSize_t
 PerlIOBuf_read(PerlIO *f, void *vbuf, Size_t count)
 {
  PerlIOBuf *b  = PerlIOSelf(f,PerlIOBuf);
- STDCHAR *buf  = (STDCHAR *) vbuf;
  if (f)
   {
    if (!b->ptr)
     PerlIO_get_base(f);
-   if (!(PerlIOBase(f)->flags & PERLIO_F_CANREAD))
-    return 0;
-   while (count > 0)
-    {
-     SSize_t avail = PerlIO_get_cnt(f);
-     SSize_t take  = (count < avail) ? count : avail;
-     if (take > 0)
-      {
-       STDCHAR *ptr = PerlIO_get_ptr(f);
-       Copy(ptr,buf,take,STDCHAR);
-       PerlIO_set_ptrcnt(f,ptr+take,(avail -= take));
-       count   -= take;
-       buf     += take;
-      }
-     if (count > 0  && avail <= 0)
-      {
-       if (PerlIO_fill(f) != 0)
-        break;
-      }
-    }
-   return (buf - (STDCHAR *) vbuf);
+   return PerlIOBase_read(f,vbuf,count);
   }
  return 0;
 }
@@ -2454,15 +2629,6 @@ PerlIOBuf_close(PerlIO *f)
  return code;
 }
 
-void
-PerlIOBuf_setlinebuf(PerlIO *f)
-{
- if (f)
-  {
-   PerlIOBase(f)->flags &= ~PERLIO_F_LINEBUF;
-  }
-}
-
 STDCHAR *
 PerlIOBuf_get_ptr(PerlIO *f)
 {
@@ -2533,10 +2699,11 @@ PerlIO_funcs PerlIO_perlio = {
  "perlio",
  sizeof(PerlIOBuf),
  PERLIO_K_BUFFERED,
- PerlIOBase_fileno,
- PerlIOBuf_open,
  PerlIOBuf_pushed,
  PerlIOBase_noop_ok,
+ PerlIOBuf_open,
+ NULL,
+ PerlIOBase_fileno,
  PerlIOBuf_read,
  PerlIOBuf_unread,
  PerlIOBuf_write,
@@ -2548,7 +2715,7 @@ PerlIO_funcs PerlIO_perlio = {
  PerlIOBase_eof,
  PerlIOBase_error,
  PerlIOBase_clearerr,
- PerlIOBuf_setlinebuf,
+ PerlIOBase_setlinebuf,
  PerlIOBuf_get_base,
  PerlIOBuf_bufsiz,
  PerlIOBuf_get_ptr,
@@ -2612,9 +2779,9 @@ PerlIOPending_set_ptrcnt(PerlIO *f, STDCHAR *ptr, SSize_t cnt)
 }
 
 IV
-PerlIOPending_pushed(PerlIO *f,const char *mode,const char *arg,STRLEN len)
+PerlIOPending_pushed(PerlIO *f,const char *mode,SV *arg)
 {
- IV code    = PerlIOBase_pushed(f,mode,arg,len);
+ IV code    = PerlIOBase_pushed(f,mode,arg);
  PerlIOl *l = PerlIOBase(f);
  /* Our PerlIO_fast_gets must match what we are pushed on,
     or sv_gets() etc. get muddled when it changes mid-string
@@ -2643,15 +2810,15 @@ PerlIOPending_read(PerlIO *f, void *vbuf, Size_t count)
  return got;
 }
 
-
 PerlIO_funcs PerlIO_pending = {
  "pending",
  sizeof(PerlIOBuf),
  PERLIO_K_BUFFERED,
- PerlIOBase_fileno,
- NULL,
  PerlIOPending_pushed,
  PerlIOBase_noop_ok,
+ NULL,
+ NULL,
+ PerlIOBase_fileno,
  PerlIOPending_read,
  PerlIOBuf_unread,
  PerlIOBuf_write,
@@ -2663,7 +2830,7 @@ PerlIO_funcs PerlIO_pending = {
  PerlIOBase_eof,
  PerlIOBase_error,
  PerlIOBase_clearerr,
- PerlIOBuf_setlinebuf,
+ PerlIOBase_setlinebuf,
  PerlIOBuf_get_base,
  PerlIOBuf_bufsiz,
  PerlIOBuf_get_ptr,
@@ -2687,11 +2854,11 @@ typedef struct
 } PerlIOCrlf;
 
 IV
-PerlIOCrlf_pushed(PerlIO *f, const char *mode,const char *arg,STRLEN len)
+PerlIOCrlf_pushed(PerlIO *f, const char *mode,SV *arg)
 {
  IV code;
  PerlIOBase(f)->flags |= PERLIO_F_CRLF;
- code = PerlIOBuf_pushed(f,mode,arg,len);
+ code = PerlIOBuf_pushed(f,mode,arg);
 #if 0
  PerlIO_debug("PerlIOCrlf_pushed f=%p %s %s fl=%08"UVxf"\n",
               f,PerlIOBase(f)->tab->name,(mode) ? mode : "(Null)",
@@ -2953,10 +3120,11 @@ PerlIO_funcs PerlIO_crlf = {
  "crlf",
  sizeof(PerlIOCrlf),
  PERLIO_K_BUFFERED|PERLIO_K_CANCRLF,
- PerlIOBase_fileno,
- PerlIOBuf_open,
  PerlIOCrlf_pushed,
  PerlIOBase_noop_ok,   /* popped */
+ PerlIOBuf_open,
+ NULL,
+ PerlIOBase_fileno,
  PerlIOBuf_read,       /* generic read works with ptr/cnt lies ... */
  PerlIOCrlf_unread,    /* Put CR,LF in buffer for each '\n' */
  PerlIOCrlf_write,     /* Put CR,LF in buffer for each '\n' */
@@ -2968,7 +3136,7 @@ PerlIO_funcs PerlIO_crlf = {
  PerlIOBase_eof,
  PerlIOBase_error,
  PerlIOBase_clearerr,
- PerlIOBuf_setlinebuf,
+ PerlIOBase_setlinebuf,
  PerlIOBuf_get_base,
  PerlIOBuf_bufsiz,
  PerlIOBuf_get_ptr,
@@ -3257,10 +3425,11 @@ PerlIO_funcs PerlIO_mmap = {
  "mmap",
  sizeof(PerlIOMmap),
  PERLIO_K_BUFFERED,
- PerlIOBase_fileno,
- PerlIOBuf_open,
  PerlIOBuf_pushed,
  PerlIOBase_noop_ok,
+ PerlIOBuf_open,
+ NULL,
+ PerlIOBase_fileno,
  PerlIOBuf_read,
  PerlIOMmap_unread,
  PerlIOMmap_write,
@@ -3272,7 +3441,7 @@ PerlIO_funcs PerlIO_mmap = {
  PerlIOBase_eof,
  PerlIOBase_error,
  PerlIOBase_clearerr,
- PerlIOBuf_setlinebuf,
+ PerlIOBase_setlinebuf,
  PerlIOMmap_get_base,
  PerlIOBuf_bufsiz,
  PerlIOBuf_get_ptr,
@@ -3293,14 +3462,15 @@ PerlIO_init(void)
   }
 }
 
-
-
 #undef PerlIO_stdin
 PerlIO *
 PerlIO_stdin(void)
 {
  if (!_perlio)
-  PerlIO_stdstreams();
+  {
+   dTHX;
+   PerlIO_stdstreams(aTHX);
+  }
  return &_perlio[1];
 }
 
@@ -3309,7 +3479,10 @@ PerlIO *
 PerlIO_stdout(void)
 {
  if (!_perlio)
-  PerlIO_stdstreams();
+  {
+   dTHX;
+   PerlIO_stdstreams(aTHX);
+  }
  return &_perlio[2];
 }
 
@@ -3318,7 +3491,10 @@ PerlIO *
 PerlIO_stderr(void)
 {
  if (!_perlio)
-  PerlIO_stdstreams();
+  {
+   dTHX;
+   PerlIO_stdstreams(aTHX);
+  }
  return &_perlio[3];
 }
 
@@ -3446,7 +3622,7 @@ PerlIO_tmpfile(void)
  FILE *stdio = PerlSIO_tmpfile();
  if (stdio)
   {
-   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),&PerlIO_stdio,"w+",Nullch,0),PerlIOStdio);
+   PerlIOStdio *s = PerlIOSelf(PerlIO_push(aTHX_ (f = PerlIO_allocate(aTHX)),&PerlIO_stdio,"w+",Nullsv),PerlIOStdio);
    s->stdio  = stdio;
   }
  return f;