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-rw-r--r--universal.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/universal.c b/universal.c
new file mode 100644
index 0000000000..830e2066ac
--- /dev/null
+++ b/universal.c
@@ -0,0 +1,232 @@
+#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;
+}
+
+static
+XS(XS_UNIVERSAL_isa)
+{
+ dXSARGS;
+ SV *sv, *rv;
+ char *name;
+
+ if (items != 2)
+ croak("Usage: UNIVERSAL::isa(reference, kind)");
+
+ sv = ST(0);
+ name = (char *)SvPV(ST(1),na);
+
+ if (!SvROK(sv)) {
+ rv = &sv_no;
+ }
+ else if((sv = (SV*)SvRV(sv)) && SvOBJECT(sv) &&
+ &sv_yes == isa_lookup(SvSTASH(sv), name, strlen(name), 0)) {
+ rv = &sv_yes;
+ }
+ else {
+ char *s;
+
+ switch (SvTYPE(sv)) {
+ case SVt_NULL:
+ case SVt_IV:
+ case SVt_NV:
+ case SVt_RV:
+ case SVt_PV:
+ case SVt_PVIV:
+ case SVt_PVNV:
+ case SVt_PVBM:
+ case SVt_PVMG: s = "SCALAR"; break;
+ case SVt_PVLV: s = "LVALUE"; break;
+ case SVt_PVAV: s = "ARRAY"; break;
+ case SVt_PVHV: s = "HASH"; break;
+ case SVt_PVCV: s = "CODE"; break;
+ case SVt_PVGV: s = "GLOB"; break;
+ case SVt_PVFM: s = "FORMATLINE"; break;
+ case SVt_PVIO: s = "FILEHANDLE"; break;
+ default: s = "UNKNOWN"; break;
+ }
+ rv = strEQ(s,name) ? &sv_yes : &sv_no;
+ }
+
+ ST(0) = rv;
+ XSRETURN(1);
+}
+
+static
+XS(XS_UNIVERSAL_can)
+{
+ dXSARGS;
+ SV *sv;
+ char *name;
+ SV *rv;
+ GV *gv;
+ CV *cvp;
+
+ 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)) && SvOBJECT(sv)) {
+ gv = gv_fetchmethod(SvSTASH(sv), name);
+
+ if(gv && GvCV(gv)) {
+ /* If the sub is only a stub then we may have a gv to AUTOLOAD */
+ GV **gvp = (GV**)hv_fetch(GvSTASH(gv), name, strlen(name), TRUE);
+ if(gvp && (cvp = GvCV(*gvp))) {
+ rv = sv_newmortal();
+ sv_setsv(rv, newRV((SV*)cvp));
+ }
+ }
+ }
+
+ ST(0) = rv;
+ XSRETURN(1);
+}
+
+static
+XS(XS_UNIVERSAL_is_instance)
+{
+ dXSARGS;
+ ST(0) = SvROK(ST(0)) ? &sv_yes : &sv_no;
+ XSRETURN(1);
+}
+
+static
+XS(XS_UNIVERSAL_class)
+{
+ dXSARGS;
+ if(SvROK(ST(0))) {
+ SV *sv = sv_newmortal();
+ sv_setpv(sv, HvNAME(SvSTASH(ST(0))));
+ ST(0) = sv;
+ }
+ XSRETURN(1);
+}
+
+static
+XS(XS_UNIVERSAL_VERSION)
+{
+ dXSARGS;
+ HV *pkg;
+ GV **gvp;
+ GV *gv;
+ SV *sv;
+ char *undef;
+
+ 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 || SvNV(ST(1)) > 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::class", XS_UNIVERSAL_class, file);
+ newXS("UNIVERSAL::is_instance", XS_UNIVERSAL_is_instance, file);
+ newXS("UNIVERSAL::VERSION", XS_UNIVERSAL_VERSION, file);
+}