/*
=for apidoc mro_get_linear_isa
Returns either C<mro_get_linear_isa_c3> or
C<mro_get_linear_isa_dfs> for the given stash,
dependant upon which MRO is in effect
for that stash. The return value is a
read-only AV*.
You are responsible for C<SvREFCNT_inc()> on the
return value if you plan to store it anywhere
semi-permanently (otherwise it might be deleted
out from under you the next time the cache is
invalidated).
=cut
*/
AV*
Perl_mro_get_linear_isa(pTHX_ HV *stash)
{
struct mro_meta* meta;
PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA;
if(!SvOOK(stash))
Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
meta = HvMROMETA(stash);
return mro_get_linear_isa_c3(stash, 0);
}
/*
=for apidoc mro_get_linear_isa
Returns either C<mro_get_linear_isa_c3> or
C<mro_get_linear_isa_dfs> for the given stash,
dependant upon which MRO is in effect
for that stash. The return value is a
read-only AV*.
You are responsible for C<SvREFCNT_inc()> on the
return value if you plan to store it anywhere
semi-permanently (otherwise it might be deleted
out from under you the next time the cache is
invalidated).
=cut
*/
AV*
Perl_mro_get_linear_isa(pTHX_ HV *stash)
{
struct mro_meta* meta;
PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA;
if(!SvOOK(stash))
Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
meta = HvMROMETA(stash);
if (!meta->mro_which)
Perl_croak(aTHX_ "panic: invalid MRO!");
return meta->mro_which->resolve(aTHX_ stash, 0);
}
/*
=for apidoc mro_package_moved
Call this function to signal to a stash that it has been assigned to
another spot in the stash hierarchy. C<stash> is the stash that has been
assigned. C<oldstash> is the stash it replaces, if any. C<gv> is the glob
that is actually being assigned to.
This can also be called with a null first argument to
indicate that C<oldstash> has been deleted.
This function invalidates isa caches on the old stash, on all subpackages
nested inside it, and on the subclasses of all those, including
non-existent packages that have corresponding entries in C<stash>.
It also sets the effective names (C<HvENAME>) on all the stashes as
appropriate.
If the C<gv> is present and is not in the symbol table, then this function
simply returns. This checked will be skipped if C<flags & 1>.
=cut
*/
void
Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash,
const GV * const gv, U32 flags)
{
SV *namesv;
HEK **namep;
I32 name_count;
HV *stashes;
HE* iter;
PERL_ARGS_ASSERT_MRO_PACKAGE_MOVED;
assert(stash || oldstash);
/* Determine the name(s) of the location that stash was assigned to
* or from which oldstash was removed.
*
* We cannot reliably use the name in oldstash, because it may have
* been deleted from the location in the symbol table that its name
* suggests, as in this case:
*
* $globref = \*foo::bar::;
* Symbol::delete_package("foo");
* *$globref = \%baz::;
* *$globref = *frelp::;
* # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0)
*
* So we get it from the gv. But, since the gv may no longer be in the
* symbol table, we check that first. The only reliable way to tell is
* to see whether its stash has an effective name and whether the gv
* resides in that stash under its name. That effective name may be
* different from what gv_fullname4 would use.
* If flags & 1, the caller has asked us to skip the check.
*/
if(!(flags & 1)) {
SV **svp;
if(
!GvSTASH(gv) || !HvENAME(GvSTASH(gv)) ||
!(svp = hv_fetchhek(GvSTASH(gv), GvNAME_HEK(gv), 0)) ||
*svp != (SV *)gv
) return;
}
assert(SvOOK(GvSTASH(gv)));
assert(GvNAMELEN(gv));
assert(GvNAME(gv)[GvNAMELEN(gv) - 1] == ':');
assert(GvNAMELEN(gv) == 1 || GvNAME(gv)[GvNAMELEN(gv) - 2] == ':');
name_count = HvAUX(GvSTASH(gv))->xhv_name_count;
if (!name_count) {
name_count = 1;
namep = &HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_name;
}
else {
namep = HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_names;
if (name_count < 0) ++namep, name_count = -name_count - 1;
}
if (name_count == 1) {
if (HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)) {
namesv = GvNAMELEN(gv) == 1
? newSVpvs_flags(":", SVs_TEMP)
: newSVpvs_flags("", SVs_TEMP);
}
else {
namesv = sv_2mortal(newSVhek(*namep));
if (GvNAMELEN(gv) == 1) sv_catpvs(namesv, ":");
else sv_catpvs(namesv, "::");
}
if (GvNAMELEN(gv) != 1) {
sv_catpvn_flags(
namesv, GvNAME(gv), GvNAMELEN(gv) - 2,
/* skip trailing :: */
GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES
);
}
}
else {
SV *aname;
namesv = sv_2mortal((SV *)newAV());
while (name_count--) {
if(HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)) {
aname = GvNAMELEN(gv) == 1
? newSVpvs(":")
: newSVpvs("");
namep++;
}
else {
aname = newSVhek(*namep++);
if (GvNAMELEN(gv) == 1) sv_catpvs(aname, ":");
else sv_catpvs(aname, "::");
}
if (GvNAMELEN(gv) != 1) {
sv_catpvn_flags(
aname, GvNAME(gv), GvNAMELEN(gv) - 2,
/* skip trailing :: */
GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES
);
}
av_push((AV *)namesv, aname);
}
}
/* Get a list of all the affected classes. */
/* We cannot simply pass them all to mro_isa_changed_in to avoid
the list, as that function assumes that only one package has
changed. It does not work with:
@foo::ISA = qw( B B::B );
*B:: = delete $::{"A::"};
as neither B nor B::B can be updated before the other, since they
will reset caches on foo, which will see either B or B::B with the
wrong name. The names must be set on *all* affected stashes before
we do anything else. (And linearisations must be cleared, too.)
*/
stashes = (HV *) sv_2mortal((SV *)newHV());
mro_gather_and_rename(
stashes, (HV *) sv_2mortal((SV *)newHV()),
stash, oldstash, namesv
);
/* Once the caches have been wiped on all the classes, call
mro_isa_changed_in on each. */
hv_iterinit(stashes);
while((iter = hv_iternext(stashes))) {
HV * const stash = *(HV **)HEK_KEY(HeKEY_hek(iter));
if(HvENAME(stash)) {
/* We have to restore the original meta->isa (that
mro_gather_and_rename set aside for us) this way, in case
one class in this list is a superclass of a another class
that we have already encountered. In such a case, meta->isa
from PL_isarev. */
struct mro_meta * const meta = HvMROMETA(stash);
if(meta->isa != (HV *)HeVAL(iter)) {
SvREFCNT_dec(meta->isa);
meta->isa
= HeVAL(iter) == &PL_sv_yes
? NULL
: (HV *)HeVAL(iter);
HeVAL(iter) = NULL; /* We donated our reference count. */
}
mro_isa_changed_in(stash);
}
}
}
/*
=for apidoc mro_get_linear_isa
Returns the mro linearisation for the given stash. By default, this
will be whatever C<mro_get_linear_isa_dfs> returns unless some
other MRO is in effect for the stash. The return value is a
read-only AV*.
You are responsible for C<SvREFCNT_inc()> on the
return value if you plan to store it anywhere
semi-permanently (otherwise it might be deleted
out from under you the next time the cache is
invalidated).
=cut
*/
AV*
Perl_mro_get_linear_isa(pTHX_ HV *stash)
{
struct mro_meta* meta;
AV *isa;
PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA;
if(!SvOOK(stash))
Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
meta = HvMROMETA(stash);
if (!meta->mro_which)
Perl_croak(aTHX_ "panic: invalid MRO!");
isa = meta->mro_which->resolve(aTHX_ stash, 0);
if (meta->mro_which != &dfs_alg) { /* skip for dfs, for speed */
SV * const namesv =
(HvENAME(stash)||HvNAME(stash))
? newSVhek(HvENAME_HEK(stash)
? HvENAME_HEK(stash)
: HvNAME_HEK(stash))
: NULL;
if(namesv && (AvFILLp(isa) == -1 || !sv_eq(*AvARRAY(isa), namesv)))
{
AV * const old = isa;
SV **svp;
SV **ovp = AvARRAY(old);
SV * const * const oend = ovp + AvFILLp(old) + 1;
isa = (AV *)sv_2mortal((SV *)newAV());
av_extend(isa, AvFILLp(isa) = AvFILLp(old)+1);
*AvARRAY(isa) = namesv;
svp = AvARRAY(isa)+1;
while (ovp < oend) *svp++ = SvREFCNT_inc(*ovp++);
}
else SvREFCNT_dec(namesv);
}
if (!meta->isa) {
HV *const isa_hash = newHV();
/* Linearisation didn't build it for us, so do it here. */
SV *const *svp = AvARRAY(isa);
SV *const *const svp_end = svp + AvFILLp(isa) + 1;
const HEK *canon_name = HvENAME_HEK(stash);
if (!canon_name) canon_name = HvNAME_HEK(stash);
while (svp < svp_end) {
(void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0);
}
(void) hv_common(isa_hash, NULL, HEK_KEY(canon_name),
HEK_LEN(canon_name), HEK_FLAGS(canon_name),
HV_FETCH_ISSTORE, &PL_sv_undef,
HEK_HASH(canon_name));
(void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0);
SvREADONLY_on(isa_hash);
meta->isa = isa_hash;
}
return isa;
}
