diff options
Diffstat (limited to 'universal.c')
| -rw-r--r-- | universal.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/universal.c b/universal.c new file mode 100644 index 0000000000..b082da67ff --- /dev/null +++ b/universal.c @@ -0,0 +1,213 @@ +#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); +} |