This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
[perl #33809] optimize macro dXSARGS
[perl5.git] / universal.c
index 39a724d..f13f8af 100644 (file)
@@ -1,6 +1,7 @@
 /*    universal.c
  *
- *    Copyright (c) 1997-2003, Larry Wall
+ *    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
+ *    2005, by Larry Wall and others
  *
  *    You may distribute under the terms of either the GNU General Public
  *    License or the Artistic License, as specified in the README file.
  * beginning." --Gandalf, relating Gollum's story
  */
 
+/* This file contains the code that implements the functions in Perl's
+ * UNIVERSAL package, such as UNIVERSAL->can().
+ */
+
 #include "EXTERN.h"
 #define PERL_IN_UNIVERSAL_C
 #include "perl.h"
@@ -44,6 +49,9 @@ S_isa_lookup(pTHX_ HV *stash, const char *name, HV* name_stash,
     if (strEQ(HvNAME(stash), name))
        return &PL_sv_yes;
 
+    if (strEQ(name, "UNIVERSAL"))
+       return &PL_sv_yes;
+
     if (level > 100)
        Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
                   HvNAME(stash));
@@ -111,8 +119,7 @@ S_isa_lookup(pTHX_ HV *stash, const char *name, HV* name_stash,
            (void)hv_store(hv,name,len,&PL_sv_no,0);
        }
     }
-
-    return boolSV(strEQ(name, "UNIVERSAL"));
+    return &PL_sv_no;
 }
 
 /*
@@ -130,7 +137,7 @@ for class names as well as for objects.
 bool
 Perl_sv_derived_from(pTHX_ SV *sv, const char *name)
 {
-    char *type;
+    const char *type;
     HV *stash;
     HV *name_stash;
 
@@ -161,15 +168,18 @@ Perl_sv_derived_from(pTHX_ SV *sv, const char *name)
 
 #include "XSUB.h"
 
-void XS_UNIVERSAL_isa(pTHX_ CV *cv);
-void XS_UNIVERSAL_can(pTHX_ CV *cv);
-void XS_UNIVERSAL_VERSION(pTHX_ CV *cv);
+PERL_XS_EXPORT_C void XS_UNIVERSAL_isa(pTHX_ CV *cv);
+PERL_XS_EXPORT_C void XS_UNIVERSAL_can(pTHX_ CV *cv);
+PERL_XS_EXPORT_C void XS_UNIVERSAL_VERSION(pTHX_ CV *cv);
 XS(XS_version_new);
 XS(XS_version_stringify);
 XS(XS_version_numify);
 XS(XS_version_vcmp);
 XS(XS_version_boolean);
 XS(XS_version_noop);
+XS(XS_version_is_alpha);
+XS(XS_version_qv);
+XS(XS_utf8_is_utf8);
 XS(XS_utf8_valid);
 XS(XS_utf8_encode);
 XS(XS_utf8_decode);
@@ -181,11 +191,15 @@ XS(XS_Internals_SvREADONLY);
 XS(XS_Internals_SvREFCNT);
 XS(XS_Internals_hv_clear_placehold);
 XS(XS_PerlIO_get_layers);
+XS(XS_Regexp_DESTROY);
+XS(XS_Internals_hash_seed);
+XS(XS_Internals_rehash_seed);
+XS(XS_Internals_HvREHASH);
 
 void
 Perl_boot_core_UNIVERSAL(pTHX)
 {
-    char *file = __FILE__;
+    const char file[] = __FILE__;
 
     newXS("UNIVERSAL::isa",             XS_UNIVERSAL_isa,         file);
     newXS("UNIVERSAL::can",             XS_UNIVERSAL_can,         file);
@@ -207,7 +221,10 @@ Perl_boot_core_UNIVERSAL(pTHX)
        newXS("version::boolean", XS_version_boolean, file);
        newXS("version::(nomethod", XS_version_noop, file);
        newXS("version::noop", XS_version_noop, file);
+       newXS("version::is_alpha", XS_version_is_alpha, file);
+       newXS("version::qv", XS_version_qv, file);
     }
+    newXS("utf8::is_utf8", XS_utf8_is_utf8, file);
     newXS("utf8::valid", XS_utf8_valid, file);
     newXS("utf8::encode", XS_utf8_encode, file);
     newXS("utf8::decode", XS_utf8_decode, file);
@@ -221,6 +238,10 @@ Perl_boot_core_UNIVERSAL(pTHX)
                XS_Internals_hv_clear_placehold, file, "\\%");
     newXSproto("PerlIO::get_layers",
                XS_PerlIO_get_layers, file, "*;@");
+    newXS("Regexp::DESTROY", XS_Regexp_DESTROY, file);
+    newXSproto("Internals::hash_seed",XS_Internals_hash_seed, file, "");
+    newXSproto("Internals::rehash_seed",XS_Internals_rehash_seed, file, "");
+    newXSproto("Internals::HvREHASH", XS_Internals_HvREHASH, file, "\\%");
 }
 
 
@@ -228,7 +249,7 @@ XS(XS_UNIVERSAL_isa)
 {
     dXSARGS;
     SV *sv;
-    char *name;
+    const char *name;
     STRLEN n_a;
 
     if (items != 2)
@@ -243,7 +264,7 @@ XS(XS_UNIVERSAL_isa)
                || (SvGMAGICAL(sv) && SvPOKp(sv) && SvCUR(sv))))
        XSRETURN_UNDEF;
 
-    name = (char *)SvPV(ST(1),n_a);
+    name = (const char *)SvPV(ST(1),n_a);
 
     ST(0) = boolSV(sv_derived_from(sv, name));
     XSRETURN(1);
@@ -253,7 +274,7 @@ XS(XS_UNIVERSAL_can)
 {
     dXSARGS;
     SV   *sv;
-    char *name;
+    const char *name;
     SV   *rv;
     HV   *pkg = NULL;
     STRLEN n_a;
@@ -270,7 +291,7 @@ XS(XS_UNIVERSAL_can)
                || (SvGMAGICAL(sv) && SvPOKp(sv) && SvCUR(sv))))
        XSRETURN_UNDEF;
 
-    name = (char *)SvPV(ST(1),n_a);
+    name = (const char *)SvPV(ST(1),n_a);
     rv = &PL_sv_undef;
 
     if (SvROK(sv)) {
@@ -299,7 +320,7 @@ XS(XS_UNIVERSAL_VERSION)
     GV **gvp;
     GV *gv;
     SV *sv;
-    char *undef;
+    const char *undef;
 
     if (SvROK(ST(0))) {
         sv = (SV*)SvRV(ST(0));
@@ -317,6 +338,8 @@ XS(XS_UNIVERSAL_VERSION)
         SV *nsv = sv_newmortal();
         sv_setsv(nsv, sv);
         sv = nsv;
+       if ( !sv_derived_from(sv, "version"))
+           upg_version(sv);
         undef = Nullch;
     }
     else {
@@ -334,25 +357,32 @@ XS(XS_UNIVERSAL_VERSION)
                             "%s does not define $%s::VERSION--version check failed",
                             HvNAME(pkg), HvNAME(pkg));
             else {
-                 char *str = SvPVx(ST(0), len);
+                  const char *str = SvPVx(ST(0), len);
 
                  Perl_croak(aTHX_
                             "%s defines neither package nor VERSION--version check failed", str);
             }
        }
-       if ( !sv_derived_from(sv, "version"))
-           sv = new_version(sv);
 
-       if ( !sv_derived_from(req, "version"))
-           req = new_version(req);
+       if ( !sv_derived_from(req, "version")) {
+           /* req may very well be R/O, so create a new object */
+           SV *nsv = sv_newmortal();
+           sv_setsv(nsv, req);
+           req = nsv;
+           upg_version(req);
+       }
 
-       if ( vcmp( SvRV(req), SvRV(sv) ) > 0 )
-           Perl_croak(aTHX_
-               "%s version %"SVf" required--this is only version %"SVf,
-               HvNAME(pkg), req, sv);
+       if ( vcmp( req, sv ) > 0 )
+           Perl_croak(aTHX_ "%s version %"SVf" (%"SVf") required--"
+                   "this is only version %"SVf" (%"SVf")", HvNAME(pkg),
+                   vnumify(req),vnormal(req),vnumify(sv),vnormal(sv));
     }
 
-    ST(0) = sv;
+    if ( SvOK(sv) && sv_derived_from(sv, "version") ) {
+       ST(0) = vnumify(sv);
+    } else {
+       ST(0) = sv;
+    }
 
     XSRETURN(1);
 }
@@ -364,15 +394,20 @@ XS(XS_version_new)
        Perl_croak(aTHX_ "Usage: version::new(class, version)");
     SP -= items;
     {
-/*     char *  class = (char *)SvPV_nolen(ST(0)); */
-        SV *version = ST(1);
+        const char *classname = SvPV_nolen(ST(0));
+        SV *vs = ST(1);
+       SV *rv;
        if (items == 3 )
        {
-           char *vs = savepvn(SvPVX(ST(2)),SvCUR(ST(2)));
-           version = Perl_newSVpvf(aTHX_ "v%s",vs);
+           vs = sv_newmortal(); 
+           Perl_sv_setpvf(aTHX_ vs,"v%s",SvPV_nolen(ST(2)));
        }
 
-       PUSHs(new_version(version));
+       rv = new_version(vs);
+       if ( strcmp(classname,"version") != 0 ) /* inherited new() */
+           sv_bless(rv, gv_stashpv(classname,TRUE));
+
+       PUSHs(sv_2mortal(rv));
        PUTBACK;
        return;
     }
@@ -380,166 +415,246 @@ XS(XS_version_new)
 
 XS(XS_version_stringify)
 {
-    dXSARGS;
-    if (items < 1)
-       Perl_croak(aTHX_ "Usage: version::stringify(lobj, ...)");
-    SP -= items;
-    {
-       SV *    lobj;
-
-        if (sv_derived_from(ST(0), "version")) {
-                SV *tmp = SvRV(ST(0));
-               lobj = tmp;
-        }
-        else
-                Perl_croak(aTHX_ "lobj is not of type version");
-
-{
-    PUSHs(vstringify(lobj));
-}
-
-       PUTBACK;
-       return;
-    }
+     dXSARGS;
+     if (items < 1)
+         Perl_croak(aTHX_ "Usage: version::stringify(lobj, ...)");
+     SP -= items;
+     {
+         SV *  lobj;
+
+         if (sv_derived_from(ST(0), "version")) {
+              SV *tmp = SvRV(ST(0));
+              lobj = tmp;
+         }
+         else
+              Perl_croak(aTHX_ "lobj is not of type version");
+
+         PUSHs(sv_2mortal(vstringify(lobj)));
+
+         PUTBACK;
+         return;
+     }
 }
 
 XS(XS_version_numify)
 {
-    dXSARGS;
-    if (items < 1)
-       Perl_croak(aTHX_ "Usage: version::numify(lobj, ...)");
-    SP -= items;
-    {
-       SV *    lobj;
+     dXSARGS;
+     if (items < 1)
+         Perl_croak(aTHX_ "Usage: version::numify(lobj, ...)");
+     SP -= items;
+     {
+         SV *  lobj;
+
+         if (sv_derived_from(ST(0), "version")) {
+              SV *tmp = SvRV(ST(0));
+              lobj = tmp;
+         }
+         else
+              Perl_croak(aTHX_ "lobj is not of type version");
+
+         PUSHs(sv_2mortal(vnumify(lobj)));
+
+         PUTBACK;
+         return;
+     }
+}
 
-        if (sv_derived_from(ST(0), "version")) {
-                SV *tmp = SvRV(ST(0));
-               lobj = tmp;
-        }
-        else
-                Perl_croak(aTHX_ "lobj is not of type version");
+XS(XS_version_vcmp)
+{
+     dXSARGS;
+     if (items < 1)
+         Perl_croak(aTHX_ "Usage: version::vcmp(lobj, ...)");
+     SP -= items;
+     {
+         SV *  lobj;
+
+         if (sv_derived_from(ST(0), "version")) {
+              SV *tmp = SvRV(ST(0));
+              lobj = tmp;
+         }
+         else
+              Perl_croak(aTHX_ "lobj is not of type version");
+
+         {
+              SV       *rs;
+              SV       *rvs;
+              SV * robj = ST(1);
+              IV        swap = (IV)SvIV(ST(2));
+
+              if ( ! sv_derived_from(robj, "version") )
+              {
+                   robj = new_version(robj);
+              }
+              rvs = SvRV(robj);
+
+              if ( swap )
+              {
+                   rs = newSViv(vcmp(rvs,lobj));
+              }
+              else
+              {
+                   rs = newSViv(vcmp(lobj,rvs));
+              }
+
+              PUSHs(sv_2mortal(rs));
+         }
+
+         PUTBACK;
+         return;
+     }
+}
 
+XS(XS_version_boolean)
 {
-    PUSHs(vnumify(lobj));
+     dXSARGS;
+     if (items < 1)
+         Perl_croak(aTHX_ "Usage: version::boolean(lobj, ...)");
+     SP -= items;
+     {
+         SV *  lobj;
+
+         if (sv_derived_from(ST(0), "version")) {
+               /* XXX If tmp serves a purpose, explain it. */
+              SV *tmp = SvRV(ST(0));
+              lobj = tmp;
+         }
+         else
+              Perl_croak(aTHX_ "lobj is not of type version");
+
+         {
+              SV       *rs;
+              rs = newSViv( vcmp(lobj,new_version(newSVpvn("0",1))) );
+              PUSHs(sv_2mortal(rs));
+         }
+
+         PUTBACK;
+         return;
+     }
 }
 
-       PUTBACK;
-       return;
-    }
+XS(XS_version_noop)
+{
+     dXSARGS;
+     if (items < 1)
+         Perl_croak(aTHX_ "Usage: version::noop(lobj, ...)");
+     {
+         SV *  lobj;
+
+         if (sv_derived_from(ST(0), "version")) {
+              SV *tmp = SvRV(ST(0));
+              lobj = tmp;
+         }
+         else
+              Perl_croak(aTHX_ "lobj is not of type version");
+
+         {
+              Perl_croak(aTHX_ "operation not supported with version object");
+         }
+
+     }
+     XSRETURN_EMPTY;
 }
 
-XS(XS_version_vcmp)
+XS(XS_version_is_alpha)
 {
     dXSARGS;
-    if (items < 1)
-       Perl_croak(aTHX_ "Usage: version::vcmp(lobj, ...)");
+    if (items != 1)
+       Perl_croak(aTHX_ "Usage: version::is_alpha(lobj)");
     SP -= items;
     {
-       SV *    lobj;
+       SV *lobj;
 
         if (sv_derived_from(ST(0), "version")) {
+                /* XXX If tmp serves a purpose, explain it. */
                 SV *tmp = SvRV(ST(0));
                lobj = tmp;
         }
         else
                 Perl_croak(aTHX_ "lobj is not of type version");
-
 {
-    SV *rs;
-    SV *rvs;
-    SV * robj = ST(1);
-    IV  swap = (IV)SvIV(ST(2));
-
-    if ( ! sv_derived_from(robj, "version") )
-    {
-       robj = new_version(robj);
-    }
-    rvs = SvRV(robj);
-
-    if ( swap )
-    {
-        rs = newSViv(vcmp(rvs,lobj));
-    }
+    const I32 len = av_len((AV *)lobj);
+    const I32 digit = SvIVX(*av_fetch((AV *)lobj, len, 0));
+    if ( digit < 0 )
+       XSRETURN_YES;
     else
-    {
-        rs = newSViv(vcmp(lobj,rvs));
-    }
-
-    PUSHs(rs);
+       XSRETURN_NO;
 }
-
        PUTBACK;
        return;
     }
 }
 
-XS(XS_version_boolean)
+XS(XS_version_qv)
 {
     dXSARGS;
-    if (items < 1)
-       Perl_croak(aTHX_ "Usage: version::boolean(lobj, ...)");
+    if (items != 1)
+       Perl_croak(aTHX_ "Usage: version::qv(ver)");
     SP -= items;
     {
-       SV *    lobj;
-
-        if (sv_derived_from(ST(0), "version")) {
-                SV *tmp = SvRV(ST(0));
-               lobj = tmp;
-        }
-        else
-                Perl_croak(aTHX_ "lobj is not of type version");
+       SV *    ver = ST(0);
+       if ( !SvVOK(ver) ) /* only need to do with if not already v-string */
+       {
+           SV *vs = sv_newmortal();
+           char *version;
+           if ( SvNOK(ver) ) /* may get too much accuracy */
+           {
+               char tbuf[64];
+               sprintf(tbuf,"%.9"NVgf, SvNVX(ver));
+               version = savepv(tbuf);
+           }
+           else
+           {
+               version = savesvpv(ver);
+           }
+           (void)scan_version(version,vs,TRUE);
+           Safefree(version);
 
-{
-    SV *rs;
-    rs = newSViv( vcmp(lobj,new_version(newSVpvn("0",1))) );
-    PUSHs(rs);
-}
+           PUSHs(vs);
+       }
+       else
+       {
+           PUSHs(sv_2mortal(new_version(ver)));
+       }
 
        PUTBACK;
        return;
     }
 }
 
-XS(XS_version_noop)
-{
-    dXSARGS;
-    if (items < 1)
-       Perl_croak(aTHX_ "Usage: version::noop(lobj, ...)");
-    {
-       SV *    lobj;
-
-        if (sv_derived_from(ST(0), "version")) {
-                SV *tmp = SvRV(ST(0));
-               lobj = tmp;
-        }
-        else
-                Perl_croak(aTHX_ "lobj is not of type version");
-
+XS(XS_utf8_is_utf8)
 {
-    Perl_croak(aTHX_ "operation not supported with version object");
-}
-
-    }
-    XSRETURN_EMPTY;
+     dXSARGS;
+     if (items != 1)
+         Perl_croak(aTHX_ "Usage: utf8::is_utf8(sv)");
+     {
+          const SV *sv = ST(0);
+         {
+              if (SvUTF8(sv))
+                   XSRETURN_YES;
+              else
+                   XSRETURN_NO;
+         }
+     }
+     XSRETURN_EMPTY;
 }
 
 XS(XS_utf8_valid)
 {
-    dXSARGS;
-    if (items != 1)
-       Perl_croak(aTHX_ "Usage: utf8::valid(sv)");
-    {
-       SV *    sv = ST(0);
- {
-  STRLEN len;
-  char *s = SvPV(sv,len);
-  if (!SvUTF8(sv) || is_utf8_string((U8*)s,len))
-   XSRETURN_YES;
-  else
-   XSRETURN_NO;
- }
-    }
-    XSRETURN_EMPTY;
+     dXSARGS;
+     if (items != 1)
+         Perl_croak(aTHX_ "Usage: utf8::valid(sv)");
+     {
+         SV *  sv = ST(0);
        {
+              STRLEN len;
+              const char *s = SvPV(sv,len);
+              if (!SvUTF8(sv) || is_utf8_string((const U8*)s,len))
+                   XSRETURN_YES;
+              else
+                   XSRETURN_NO;
        }
+     }
+     XSRETURN_EMPTY;
 }
 
 XS(XS_utf8_encode)
@@ -562,9 +677,7 @@ XS(XS_utf8_decode)
        Perl_croak(aTHX_ "Usage: utf8::decode(sv)");
     {
        SV *    sv = ST(0);
-       bool    RETVAL;
-
-       RETVAL = sv_utf8_decode(sv);
+       const bool RETVAL = sv_utf8_decode(sv);
        ST(0) = boolSV(RETVAL);
        sv_2mortal(ST(0));
     }
@@ -594,16 +707,9 @@ XS(XS_utf8_downgrade)
        Perl_croak(aTHX_ "Usage: utf8::downgrade(sv, failok=0)");
     {
        SV *    sv = ST(0);
-       bool    failok;
-       bool    RETVAL;
-
-       if (items < 2)
-           failok = 0;
-       else {
-           failok = (int)SvIV(ST(1));
-       }
+        const bool failok = (items < 2) ? 0 : (int)SvIV(ST(1));
+        const bool RETVAL = sv_utf8_downgrade(sv, failok);
 
-       RETVAL = sv_utf8_downgrade(sv, failok);
        ST(0) = boolSV(RETVAL);
        sv_2mortal(ST(0));
     }
@@ -613,7 +719,7 @@ XS(XS_utf8_downgrade)
 XS(XS_utf8_native_to_unicode)
 {
  dXSARGS;
- UV uv = SvUV(ST(0));
const UV uv = SvUV(ST(0));
 
  if (items > 1)
      Perl_croak(aTHX_ "Usage: utf8::native_to_unicode(sv)");
@@ -625,7 +731,7 @@ XS(XS_utf8_native_to_unicode)
 XS(XS_utf8_unicode_to_native)
 {
  dXSARGS;
- UV uv = SvUV(ST(0));
const UV uv = SvUV(ST(0));
 
  if (items > 1)
      Perl_croak(aTHX_ "Usage: utf8::unicode_to_native(sv)");
@@ -638,6 +744,7 @@ XS(XS_Internals_SvREADONLY) /* This is dangerous stuff. */
 {
     dXSARGS;
     SV *sv = SvRV(ST(0));
+
     if (items == 1) {
         if (SvREADONLY(sv))
             XSRETURN_YES;
@@ -662,6 +769,7 @@ XS(XS_Internals_SvREFCNT)   /* This is dangerous stuff. */
 {
     dXSARGS;
     SV *sv = SvRV(ST(0));
+
     if (items == 1)
         XSRETURN_IV(SvREFCNT(sv) - 1); /* Minus the ref created for us. */
     else if (items == 2) {
@@ -672,56 +780,21 @@ XS(XS_Internals_SvREFCNT) /* This is dangerous stuff. */
     XSRETURN_UNDEF; /* Can't happen. */
 }
 
-/* Maybe this should return the number of placeholders found in scalar context,
-   and a list of them in list context.  */
 XS(XS_Internals_hv_clear_placehold)
 {
     dXSARGS;
     HV *hv = (HV *) SvRV(ST(0));
 
-    /* I don't care how many parameters were passed in, but I want to avoid
-       the unused variable warning. */
-
-    items = (I32)HvPLACEHOLDERS(hv);
-
-    if (items) {
-        HE *entry;
-        I32 riter = HvRITER(hv);
-        HE *eiter = HvEITER(hv);
-        hv_iterinit(hv);
-        /* This may look suboptimal with the items *after* the iternext, but
-           it's quite deliberate. We only get here with items==0 if we've
-           just deleted the last placeholder in the hash. If we've just done
-           that then it means that the hash is in lazy delete mode, and the
-           HE is now only referenced in our iterator. If we just quit the loop
-           and discarded our iterator then the HE leaks. So we do the && the
-           other way to ensure iternext is called just one more time, which
-           has the side effect of triggering the lazy delete.  */
-        while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))
-            && items) {
-            SV *val = hv_iterval(hv, entry);
-
-            if (val == &PL_sv_undef) {
-
-                /* It seems that I have to go back in the front of the hash
-                   API to delete a hash, even though I have a HE structure
-                   pointing to the very entry I want to delete, and could hold
-                   onto the previous HE that points to it. And it's easier to
-                   go in with SVs as I can then specify the precomputed hash,
-                   and don't have fun and games with utf8 keys.  */
-                SV *key = hv_iterkeysv(entry);
-
-                hv_delete_ent (hv, key, G_DISCARD, HeHASH(entry));
-                items--;
-            }
-        }
-        HvRITER(hv) = riter;
-        HvEITER(hv) = eiter;
-    }
-
+    if (items != 1)
+       Perl_croak(aTHX_ "Usage: UNIVERSAL::hv_clear_placeholders(hv)");
+    hv_clear_placeholders(hv);
     XSRETURN(0);
 }
 
+XS(XS_Regexp_DESTROY)
+{
+}
+
 XS(XS_PerlIO_get_layers)
 {
     dXSARGS;
@@ -736,14 +809,13 @@ XS(XS_PerlIO_get_layers)
        bool    details = FALSE;
 
        if (items > 1) {
-            SV **popuntil = MARK + 1;
             SV **svp;
             
             for (svp = MARK + 2; svp <= SP; svp += 2) {
                  SV **varp = svp;
                  SV **valp = svp + 1;
                  STRLEN klen;
-                 char *key = SvPV(*varp, klen);
+                  const char *key = SvPV(*varp, klen);
 
                  switch (*key) {
                  case 'i':
@@ -782,7 +854,7 @@ XS(XS_PerlIO_get_layers)
             if (SvROK(sv) && isGV(SvRV(sv)))
                  gv = (GV*)SvRV(sv);
             else
-                 gv = gv_fetchpv(SvPVX(sv), FALSE, SVt_PVIO);
+                 gv = gv_fetchsv(sv, FALSE, SVt_PVIO);
        }
 
        if (gv && (io = GvIO(gv))) {
@@ -848,3 +920,43 @@ XS(XS_PerlIO_get_layers)
     XSRETURN(0);
 }
 
+XS(XS_Internals_hash_seed)
+{
+    /* Using dXSARGS would also have dITEM and dSP,
+     * which define 2 unused local variables.  */
+    dAXMARK;
+    XSRETURN_UV(PERL_HASH_SEED);
+}
+
+XS(XS_Internals_rehash_seed)
+{
+    /* Using dXSARGS would also have dITEM and dSP,
+     * which define 2 unused local variables.  */
+    dAXMARK;
+    XSRETURN_UV(PL_rehash_seed);
+}
+
+XS(XS_Internals_HvREHASH)      /* Subject to change  */
+{
+    dXSARGS;
+    if (SvROK(ST(0))) {
+       const HV *hv = (HV *) SvRV(ST(0));
+       if (items == 1 && SvTYPE(hv) == SVt_PVHV) {
+           if (HvREHASH(hv))
+               XSRETURN_YES;
+           else
+               XSRETURN_NO;
+       }
+    }
+    Perl_croak(aTHX_ "Internals::HvREHASH $hashref");
+}
+
+/*
+ * Local variables:
+ * c-indentation-style: bsd
+ * c-basic-offset: 4
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vim: shiftwidth=4:
+*/