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tag: perl-5.003_97f
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#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
/*
* Contributed by Graham Barr <Graham.Barr@tiuk.ti.com>
* The main guts of traverse_isa was actually copied from gv_fetchmeth
*/
static SV *
isa_lookup(stash, name, len, level)
HV *stash;
char *name;
int len;
int level;
{
AV* av;
GV* gv;
GV** gvp;
HV* hv = Nullhv;
if (!stash)
return &sv_undef;
if(strEQ(HvNAME(stash), name))
return &sv_yes;
if (level > 100)
croak("Recursive inheritance detected");
gvp = (GV**)hv_fetch(stash, "::ISA::CACHE::", 14, FALSE);
if (gvp && (gv = *gvp) != (GV*)&sv_undef && (hv = GvHV(gv))) {
SV* sv;
SV** svp = (SV**)hv_fetch(hv, name, len, FALSE);
if (svp && (sv = *svp) != (SV*)&sv_undef)
return sv;
}
gvp = (GV**)hv_fetch(stash,"ISA",3,FALSE);
if (gvp && (gv = *gvp) != (GV*)&sv_undef && (av = GvAV(gv))) {
if(!hv) {
gvp = (GV**)hv_fetch(stash, "::ISA::CACHE::", 14, TRUE);
gv = *gvp;
if (SvTYPE(gv) != SVt_PVGV)
gv_init(gv, stash, "::ISA::CACHE::", 14, TRUE);
hv = GvHVn(gv);
}
if(hv) {
SV** svp = AvARRAY(av);
I32 items = AvFILL(av) + 1;
while (items--) {
SV* sv = *svp++;
HV* basestash = gv_stashsv(sv, FALSE);
if (!basestash) {
if (dowarn)
warn("Can't locate package %s for @%s::ISA",
SvPVX(sv), HvNAME(stash));
continue;
}
if(&sv_yes == isa_lookup(basestash, name, len, level + 1)) {
(void)hv_store(hv,name,len,&sv_yes,0);
return &sv_yes;
}
}
(void)hv_store(hv,name,len,&sv_no,0);
}
}
return &sv_no;
}
bool
sv_derived_from(sv, name)
SV * sv ;
char * name ;
{
SV *rv;
char *type;
HV *stash;
stash = Nullhv;
type = Nullch;
if (SvGMAGICAL(sv))
mg_get(sv) ;
if (SvROK(sv)) {
sv = SvRV(sv);
type = sv_reftype(sv,0);
if(SvOBJECT(sv))
stash = SvSTASH(sv);
}
else {
stash = gv_stashsv(sv, FALSE);
}
return (type && strEQ(type,name)) ||
(stash && isa_lookup(stash, name, strlen(name), 0) == &sv_yes)
? TRUE
: FALSE ;
}
static
XS(XS_UNIVERSAL_isa)
{
dXSARGS;
SV *sv;
char *name;
if (items != 2)
croak("Usage: UNIVERSAL::isa(reference, kind)");
sv = ST(0);
name = (char *)SvPV(ST(1),na);
ST(0) = boolSV(sv_derived_from(sv, name));
XSRETURN(1);
}
static
XS(XS_UNIVERSAL_can)
{
dXSARGS;
SV *sv;
char *name;
SV *rv;
HV *pkg = NULL;
if (items != 2)
croak("Usage: UNIVERSAL::can(object-ref, method)");
sv = ST(0);
name = (char *)SvPV(ST(1),na);
rv = &sv_undef;
if(SvROK(sv)) {
sv = (SV*)SvRV(sv);
if(SvOBJECT(sv))
pkg = SvSTASH(sv);
}
else {
pkg = gv_stashsv(sv, FALSE);
}
if (pkg) {
GV *gv = gv_fetchmethod_autoload(pkg, name, FALSE);
if (gv && isGV(gv))
rv = sv_2mortal(newRV((SV*)GvCV(gv)));
}
ST(0) = rv;
XSRETURN(1);
}
static
XS(XS_UNIVERSAL_VERSION)
{
dXSARGS;
HV *pkg;
GV **gvp;
GV *gv;
SV *sv;
char *undef;
double req;
if(SvROK(ST(0))) {
sv = (SV*)SvRV(ST(0));
if(!SvOBJECT(sv))
croak("Cannot find version of an unblessed reference");
pkg = SvSTASH(sv);
}
else {
pkg = gv_stashsv(ST(0), FALSE);
}
gvp = pkg ? (GV**)hv_fetch(pkg,"VERSION",7,FALSE) : Null(GV**);
if (gvp && (gv = *gvp) != (GV*)&sv_undef && (sv = GvSV(gv))) {
SV *nsv = sv_newmortal();
sv_setsv(nsv, sv);
sv = nsv;
undef = Nullch;
}
else {
sv = (SV*)&sv_undef;
undef = "(undef)";
}
if (items > 1 && (undef || (req = SvNV(ST(1)), req > SvNV(sv))))
croak("%s version %s required--this is only version %s",
HvNAME(pkg), SvPV(ST(1),na), undef ? undef : SvPV(sv,na));
ST(0) = sv;
XSRETURN(1);
}
void
boot_core_UNIVERSAL()
{
char *file = __FILE__;
newXS("UNIVERSAL::isa", XS_UNIVERSAL_isa, file);
newXS("UNIVERSAL::can", XS_UNIVERSAL_can, file);
newXS("UNIVERSAL::VERSION", XS_UNIVERSAL_VERSION, file);
}
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