misc optimizing in DynaLoader

dl_last_error is "#define dl_last_error	(SvPVX(MY_CXT.x_dl_last_error))"
since the data is already in a SV *, use newSVsv instead of turning it into
a strlen-ed (eventually) char *.

-win32 dl_load_file never uses flags, so don't do a SvIV in void context
- dl_load_file cant use "flags=NULL" because of test
"calling DynaLoader::dl_load_file() with no argument" in DynaLoader.t
-OS_Error_String stop repeatedly computing address into MY_CXT and
 derefing after PerlProc_GetOSError

function sizes in machine code bytes on VC 2003
b4 0x69 OS_Error_String af 0x67
b4 0x9D _XS_DynaLoader_dl_error af 0x6B
b4 0x108 _XS_DynaLoader_dl_load_file af 0xD6

12 files changed, 44 insertions, 31 deletions

diff --git a/ext/DynaLoader/DynaLoader_pm.PL b/ext/DynaLoader/DynaLoader_pm.PL
index e3df1cd1d8..2809e46892 100644
--- a/ext/DynaLoader/DynaLoader_pm.PL
+++ b/ext/DynaLoader/DynaLoader_pm.PL
@@ -85,7 +85,7 @@ package DynaLoader;
 # Tim.Bunce@ig.co.uk, August 1994
 
 BEGIN {
-    $VERSION = '1.27';
+    $VERSION = '1.28';
 }
 
 use Config;
diff --git a/ext/DynaLoader/dl_aix.xs b/ext/DynaLoader/dl_aix.xs
index 548e4ed973..dc20b74256 100644
--- a/ext/DynaLoader/dl_aix.xs
+++ b/ext/DynaLoader/dl_aix.xs
@@ -759,11 +759,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_dllload.xs b/ext/DynaLoader/dl_dllload.xs
index ff0c7a9572..1f99b61247 100644
--- a/ext/DynaLoader/dl_dllload.xs
+++ b/ext/DynaLoader/dl_dllload.xs
@@ -184,11 +184,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
     XSRETURN(1);
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_dlopen.xs b/ext/DynaLoader/dl_dlopen.xs
index 2759709d2e..c3df9eacf9 100644
--- a/ext/DynaLoader/dl_dlopen.xs
+++ b/ext/DynaLoader/dl_dlopen.xs
@@ -259,11 +259,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_dyld.xs b/ext/DynaLoader/dl_dyld.xs
index 2ed10bb6bc..3027ddae9a 100644
--- a/ext/DynaLoader/dl_dyld.xs
+++ b/ext/DynaLoader/dl_dyld.xs
@@ -213,11 +213,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_freemint.xs b/ext/DynaLoader/dl_freemint.xs
index f154dcbec6..0bf620ed5d 100644
--- a/ext/DynaLoader/dl_freemint.xs
+++ b/ext/DynaLoader/dl_freemint.xs
@@ -191,12 +191,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
     XSRETURN(1);
 
-char *
+SV *
 dl_error()
-    PREINIT:
-    dMY_CXT;
     CODE:
-    RETVAL = dl_last_error ;
+    dMY_CXT;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_hpux.xs b/ext/DynaLoader/dl_hpux.xs
index 6c7b3e4d8a..2844d2a05f 100644
--- a/ext/DynaLoader/dl_hpux.xs
+++ b/ext/DynaLoader/dl_hpux.xs
@@ -171,11 +171,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      filename, NULL,
 					      XS_DYNAMIC_FILENAME)));
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_symbian.xs b/ext/DynaLoader/dl_symbian.xs
index b509a6a19f..c17f397487 100644
--- a/ext/DynaLoader/dl_symbian.xs
+++ b/ext/DynaLoader/dl_symbian.xs
@@ -213,11 +213,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dl_vms.xs b/ext/DynaLoader/dl_vms.xs
index 23cf11b97d..bc9782cced 100644
--- a/ext/DynaLoader/dl_vms.xs
+++ b/ext/DynaLoader/dl_vms.xs
@@ -347,13 +347,13 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					      XS_DYNAMIC_FILENAME)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error ;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
-      RETVAL
+    RETVAL
 
 #if defined(USE_ITHREADS)
 
diff --git a/ext/DynaLoader/dl_win32.xs b/ext/DynaLoader/dl_win32.xs
index ac59e11f53..178ca7c142 100644
--- a/ext/DynaLoader/dl_win32.xs
+++ b/ext/DynaLoader/dl_win32.xs
@@ -47,10 +47,13 @@ OS_Error_String(pTHX)
     dMY_CXT;
     DWORD err = GetLastError();
     STRLEN len;
-    if (!dl_error_sv)
-	dl_error_sv = newSVpvs("");
-    PerlProc_GetOSError(dl_error_sv,err);
-    return SvPV(dl_error_sv,len);
+    SV ** l_dl_error_svp = &dl_error_sv;
+    SV * l_dl_error_sv;
+    if (!*l_dl_error_svp)
+	*l_dl_error_svp = newSVpvs("");
+    l_dl_error_sv = *l_dl_error_svp;
+    PerlProc_GetOSError(l_dl_error_sv,err);
+    return SvPV(l_dl_error_sv,len);
 }
 
 static void
@@ -114,11 +117,14 @@ BOOT:
 void
 dl_load_file(filename,flags=0)
     char *		filename
-    int			flags
+#flags is unused
+    SV *		flags = NO_INIT
     PREINIT:
     void *retv;
+    SV * retsv;
     CODE:
   {
+    PERL_UNUSED_VAR(flags);
     DLDEBUG(1,PerlIO_printf(Perl_debug_log,"dl_load_file(%s):\n", filename));
     if (dl_static_linked(filename) == 0) {
 	retv = PerlProc_DynaLoad(filename);
@@ -126,12 +132,15 @@ dl_load_file(filename,flags=0)
     else
 	retv = (void*) Win_GetModuleHandle(NULL);
     DLDEBUG(2,PerlIO_printf(Perl_debug_log," libref=%x\n", retv));
-    ST(0) = sv_newmortal() ;
-    if (retv == NULL)
+
+    if (retv == NULL) {
 	SaveError(aTHX_ "load_file:%s",
 		  OS_Error_String(aTHX)) ;
+	retsv = &PL_sv_undef;
+    }
     else
-	sv_setiv( ST(0), (IV)retv);
+	retsv = sv_2mortal(newSViv((IV)retv));
+    ST(0) = retsv;
   }
 
 int
@@ -186,11 +195,11 @@ dl_install_xsub(perl_name, symref, filename="$Package")
 					filename)));
 
 
-char *
+SV *
 dl_error()
     CODE:
     dMY_CXT;
-    RETVAL = dl_last_error;
+    RETVAL = newSVsv(MY_CXT.x_dl_last_error);
     OUTPUT:
     RETVAL
 
diff --git a/ext/DynaLoader/dlutils.c b/ext/DynaLoader/dlutils.c
index f8b23ccf0e..96ea8befa5 100644
--- a/ext/DynaLoader/dlutils.c
+++ b/ext/DynaLoader/dlutils.c
@@ -79,12 +79,13 @@ dl_unload_all_files(pTHX_ void *unused)
 
     if ((sub = get_cvs("DynaLoader::dl_unload_file", 0)) != NULL) {
         dl_librefs = get_av("DynaLoader::dl_librefs", 0);
+        EXTEND(SP,1);
         while ((dl_libref = av_pop(dl_librefs)) != &PL_sv_undef) {
            dSP;
            ENTER;
            SAVETMPS;
            PUSHMARK(SP);
-           XPUSHs(sv_2mortal(dl_libref));
+           PUSHs(sv_2mortal(dl_libref));
            PUTBACK;
            call_sv((SV*)sub, G_DISCARD | G_NODEBUG);
            FREETMPS;
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 1e4e7b2c7f..793cc839b8 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -144,6 +144,10 @@ L<IO::Socket> has been upgraded from version 1.37 to 1.38.
 
 Document the limitations of the isconnected() method.  [perl #123096]
 
+=item *
+
+L<DynaLoader> has been upgraded from version 1.27 to 1.28.
+
 =back
 
 =head2 Removed Modules and Pragmata