This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
In XS_PerlIO_get_layers() take advantage of the implementation of
authorNicholas Clark <nick@ccl4.org>
Sat, 2 Feb 2008 11:05:17 +0000 (11:05 +0000)
committerNicholas Clark <nick@ccl4.org>
Sat, 2 Feb 2008 11:05:17 +0000 (11:05 +0000)
PerlIO_get_layers(), by co-opting the new SVs it creates, rather than
copying them.

p4raw-id: //depot/perl@33182

perlio.c
universal.c

index 76fe225..3cb591d 100644 (file)
--- a/perlio.c
+++ b/perlio.c
@@ -759,6 +759,11 @@ PerlIO_get_layers(pTHX_ PerlIO *f)
        PerlIOl *l = PerlIOBase(f);
 
        while (l) {
+           /* There is some collusion in the implementation of
+              XS_PerlIO_get_layers - it knows that name and flags are
+              generated as fresh SVs here, and takes advantage of that to
+              "copy" them by taking a reference. If it changes here, it needs
+              to change there too.  */
            SV * const name = l->tab && l->tab->name ?
            newSVpv(l->tab->name, 0) : &PL_sv_undef;
            SV * const arg = l->tab && l->tab->Getarg ?
index 6860cec..ce73c82 100644 (file)
@@ -969,16 +969,22 @@ XS(XS_PerlIO_get_layers)
                  const bool flgok = flgsvp && *flgsvp && SvIOK(*flgsvp);
 
                  if (details) {
+                     /* Indents of 5? Yuck.  */
+                     /* We know that PerlIO_get_layers creates a new SV for
+                        the name and flags, so we can just take a reference
+                        and "steal" it when we free the AV below.  */
                       XPUSHs(namok
-                             ? sv_2mortal(newSVpvn(SvPVX_const(*namsvp), SvCUR(*namsvp)))
+                             ? sv_2mortal(SvREFCNT_inc_simple_NN(*namsvp))
                              : &PL_sv_undef);
                       XPUSHs(argok
-                             ? sv_2mortal(newSVpvn(SvPVX_const(*argsvp), SvCUR(*argsvp)))
+                             ? newSVpvn_flags(SvPVX_const(*argsvp),
+                                              SvCUR(*argsvp),
+                                              (SvUTF8(*argsvp) ? SVf_UTF8 : 0)
+                                              | SVs_TEMP)
+                             : &PL_sv_undef);
+                      XPUSHs(namok
+                             ? sv_2mortal(SvREFCNT_inc_simple_NN(*flgsvp))
                              : &PL_sv_undef);
-                      if (flgok)
-                           mXPUSHi(SvIVX(*flgsvp));
-                      else
-                           XPUSHs(&PL_sv_undef);
                       nitem += 3;
                  }
                  else {
@@ -987,8 +993,7 @@ XS(XS_PerlIO_get_layers)
                                                 SVfARG(*namsvp),
                                                 SVfARG(*argsvp))));
                       else if (namok)
-                           XPUSHs(sv_2mortal(Perl_newSVpvf(aTHX_ "%"SVf,
-                                                SVfARG(*namsvp))));
+                          XPUSHs(sv_2mortal(SvREFCNT_inc_simple_NN(*namsvp)));
                       else
                            XPUSHs(&PL_sv_undef);
                       nitem++;