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gv.c
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gv.c
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/* gv.c
*
* Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
* 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*
*/
/*
* 'Mercy!' cried Gandalf. 'If the giving of information is to be the cure
* of your inquisitiveness, I shall spend all the rest of my days in answering
* you. What more do you want to know?'
* 'The names of all the stars, and of all living things, and the whole
* history of Middle-earth and Over-heaven and of the Sundering Seas,'
* laughed Pippin.
*
* [p.599 of _The Lord of the Rings_, III/xi: "The Palantír"]
*/
/*
=head1 GV Handling and Stashes
A GV is a structure which corresponds to to a Perl typeglob, ie *foo.
It is a structure that holds a pointer to a scalar, an array, a hash etc,
corresponding to $foo, @foo, %foo.
GVs are usually found as values in stashes (symbol table hashes) where
Perl stores its global variables.
A B<stash> is a hash that contains all variables that are defined
within a package. See L<perlguts/Stashes and Globs>
=for apidoc Ayh||GV
=cut
*/
#include "EXTERN.h"
#define PERL_IN_GV_C
#include "perl.h"
#include "overload.inc"
#include "keywords.h"
#include "feature.h"
static const char S_autoload[] = "AUTOLOAD";
#define S_autolen (sizeof("AUTOLOAD")-1)
/*
=for apidoc gv_add_by_type
Make sure there is a slot of type C<type> in the GV C<gv>.
=cut
*/
GV *
Perl_gv_add_by_type(pTHX_ GV *gv, svtype type)
{
SV **where;
if (
!gv
|| (
SvTYPE((const SV *)gv) != SVt_PVGV
&& SvTYPE((const SV *)gv) != SVt_PVLV
)
) {
const char *what;
if (type == SVt_PVIO) {
/*
* if it walks like a dirhandle, then let's assume that
* this is a dirhandle.
*/
what = OP_IS_DIRHOP(PL_op->op_type) ?
"dirhandle" : "filehandle";
} else if (type == SVt_PVHV) {
what = "hash";
} else {
what = type == SVt_PVAV ? "array" : "scalar";
}
Perl_croak(aTHX_ "Bad symbol for %s", what);
}
if (type == SVt_PVHV) {
where = (SV **)&GvHV(gv);
} else if (type == SVt_PVAV) {
where = (SV **)&GvAV(gv);
} else if (type == SVt_PVIO) {
where = (SV **)&GvIOp(gv);
} else {
where = &GvSV(gv);
}
if (!*where)
{
*where = newSV_type(type);
if ( type == SVt_PVAV
&& memEQs(GvNAME(gv), GvNAMELEN(gv), "ISA"))
{
sv_magic(*where, (SV *)gv, PERL_MAGIC_isa, NULL, 0);
}
}
return gv;
}
/*
=for apidoc gv_fetchfile
=for apidoc_item gv_fetchfile_flags
These return the debugger glob for the file (compiled by Perl) whose name is
given by the C<name> parameter.
There are currently exactly two differences between these functions.
The C<name> parameter to C<gv_fetchfile> is a C string, meaning it is
C<NUL>-terminated; whereas the C<name> parameter to C<gv_fetchfile_flags> is a
Perl string, whose length (in bytes) is passed in via the C<namelen> parameter
This means the name may contain embedded C<NUL> characters.
C<namelen> doesn't exist in plain C<gv_fetchfile>).
The other difference is that C<gv_fetchfile_flags> has an extra C<flags>
parameter, which is currently completely ignored, but allows for possible
future extensions.
=cut
*/
GV *
Perl_gv_fetchfile(pTHX_ const char *name)
{
PERL_ARGS_ASSERT_GV_FETCHFILE;
return gv_fetchfile_flags(name, strlen(name), 0);
}
GV *
Perl_gv_fetchfile_flags(pTHX_ const char *const name, const STRLEN namelen,
const U32 flags)
{
char smallbuf[128];
char *tmpbuf;
const STRLEN tmplen = namelen + 2;
GV *gv;
PERL_ARGS_ASSERT_GV_FETCHFILE_FLAGS;
PERL_UNUSED_ARG(flags);
if (!PL_defstash)
return NULL;
if (tmplen <= sizeof smallbuf)
tmpbuf = smallbuf;
else
Newx(tmpbuf, tmplen, char);
/* This is where the debugger's %{"::_<$filename"} hash is created */
tmpbuf[0] = '_';
tmpbuf[1] = '<';
memcpy(tmpbuf + 2, name, namelen);
GV **gvp = (GV**)hv_fetch(PL_defstash, tmpbuf, tmplen, (flags & GVF_NOADD) ? FALSE : TRUE);
if (gvp) {
gv = *gvp;
if (!isGV(gv)) {
gv_init(gv, PL_defstash, tmpbuf, tmplen, FALSE);
#ifdef PERL_DONT_CREATE_GVSV
GvSV(gv) = newSVpvn(name, namelen);
#else
sv_setpvn(GvSV(gv), name, namelen);
#endif
}
if (PERLDB_LINE_OR_SAVESRC && !GvAV(gv))
hv_magic(GvHVn(gv), GvAVn(gv), PERL_MAGIC_dbfile);
}
else {
gv = NULL;
}
if (tmpbuf != smallbuf)
Safefree(tmpbuf);
return gv;
}
/*
=for apidoc gv_const_sv
If C<gv> is a typeglob whose subroutine entry is a constant sub eligible for
inlining, or C<gv> is a placeholder reference that would be promoted to such
a typeglob, then returns the value returned by the sub. Otherwise, returns
C<NULL>.
=cut
*/
SV *
Perl_gv_const_sv(pTHX_ GV *gv)
{
PERL_ARGS_ASSERT_GV_CONST_SV;
PERL_UNUSED_CONTEXT;
if (SvTYPE(gv) == SVt_PVGV)
return cv_const_sv(GvCVu(gv));
return SvROK(gv) && SvTYPE(SvRV(gv)) != SVt_PVAV && SvTYPE(SvRV(gv)) != SVt_PVCV ? SvRV(gv) : NULL;
}
GP *
Perl_newGP(pTHX_ GV *const gv)
{
GP *gp;
U32 hash;
const char *file;
STRLEN len;
PERL_ARGS_ASSERT_NEWGP;
Newxz(gp, 1, GP);
gp->gp_egv = gv; /* allow compiler to reuse gv after this */
#ifndef PERL_DONT_CREATE_GVSV
gp->gp_sv = newSV_type(SVt_NULL);
#endif
/* PL_curcop may be null here. E.g.,
INIT { bless {} and exit }
frees INIT before looking up DESTROY (and creating *DESTROY)
*/
if (PL_curcop) {
char *tmp= CopFILE(PL_curcop);
gp->gp_line = CopLINE(PL_curcop); /* 0 otherwise Newxz */
if (tmp) {
file = tmp;
len = CopFILE_LEN(PL_curcop);
}
else goto no_file;
}
else {
no_file:
file = "";
len = 0;
}
PERL_HASH(hash, file, len);
gp->gp_file_hek = share_hek(file, len, hash);
gp->gp_refcnt = 1;
return gp;
}
/* Assign CvGV(cv) = gv, handling weak references.
* See also S_anonymise_cv_maybe */
void
Perl_cvgv_set(pTHX_ CV* cv, GV* gv)
{
GV * const oldgv = CvNAMED(cv) ? NULL : SvANY(cv)->xcv_gv_u.xcv_gv;
HEK *hek;
PERL_ARGS_ASSERT_CVGV_SET;
if (oldgv == gv)
return;
if (oldgv) {
if (CvCVGV_RC(cv)) {
SvREFCNT_dec_NN(oldgv);
CvCVGV_RC_off(cv);
}
else {
sv_del_backref(MUTABLE_SV(oldgv), MUTABLE_SV(cv));
}
}
else if ((hek = CvNAME_HEK(cv))) {
unshare_hek(hek);
CvLEXICAL_off(cv);
}
CvNAMED_off(cv);
SvANY(cv)->xcv_gv_u.xcv_gv = gv;
assert(!CvCVGV_RC(cv));
if (!gv)
return;
if (isGV_with_GP(gv) && GvGP(gv) && (GvCV(gv) == cv || GvFORM(gv) == cv))
Perl_sv_add_backref(aTHX_ MUTABLE_SV(gv), MUTABLE_SV(cv));
else {
CvCVGV_RC_on(cv);
SvREFCNT_inc_simple_void_NN(gv);
}
}
/* Convert CvSTASH + CvNAME_HEK into a GV. Conceptually, all subs have a
GV, but for efficiency that GV may not in fact exist. This function,
called by CvGV, reifies it. */
GV *
Perl_cvgv_from_hek(pTHX_ CV *cv)
{
GV *gv;
SV **svp;
PERL_ARGS_ASSERT_CVGV_FROM_HEK;
assert(SvTYPE(cv) == SVt_PVCV);
if (!CvSTASH(cv)) return NULL;
ASSUME(CvNAME_HEK(cv));
svp = hv_fetchhek(CvSTASH(cv), CvNAME_HEK(cv), 0);
gv = MUTABLE_GV(svp && *svp ? *svp : newSV_type(SVt_NULL));
if (!isGV(gv))
gv_init_pvn(gv, CvSTASH(cv), HEK_KEY(CvNAME_HEK(cv)),
HEK_LEN(CvNAME_HEK(cv)),
SVf_UTF8 * cBOOL(HEK_UTF8(CvNAME_HEK(cv))));
if (!CvNAMED(cv)) { /* gv_init took care of it */
assert (SvANY(cv)->xcv_gv_u.xcv_gv == gv);
return gv;
}
unshare_hek(CvNAME_HEK(cv));
CvNAMED_off(cv);
SvANY(cv)->xcv_gv_u.xcv_gv = gv;
if (svp && *svp) SvREFCNT_inc_simple_void_NN(gv);
CvCVGV_RC_on(cv);
return gv;
}
/* Assign CvSTASH(cv) = st, handling weak references. */
void
Perl_cvstash_set(pTHX_ CV *cv, HV *st)
{
HV *oldst = CvSTASH(cv);
PERL_ARGS_ASSERT_CVSTASH_SET;
if (oldst == st)
return;
if (oldst)
sv_del_backref(MUTABLE_SV(oldst), MUTABLE_SV(cv));
SvANY(cv)->xcv_stash = st;
if (st)
Perl_sv_add_backref(aTHX_ MUTABLE_SV(st), MUTABLE_SV(cv));
}
/*
=for apidoc gv_init_pvn
Converts a scalar into a typeglob. This is an incoercible typeglob;
assigning a reference to it will assign to one of its slots, instead of
overwriting it as happens with typeglobs created by C<SvSetSV>. Converting
any scalar that is C<SvOK()> may produce unpredictable results and is reserved
for perl's internal use.
C<gv> is the scalar to be converted.
C<stash> is the parent stash/package, if any.
C<name> and C<len> give the name. The name must be unqualified;
that is, it must not include the package name. If C<gv> is a
stash element, it is the caller's responsibility to ensure that the name
passed to this function matches the name of the element. If it does not
match, perl's internal bookkeeping will get out of sync.
C<flags> can be set to C<SVf_UTF8> if C<name> is a UTF-8 string, or
the return value of SvUTF8(sv). It can also take the
C<GV_ADDMULTI> flag, which means to pretend that the GV has been
seen before (i.e., suppress "Used once" warnings).
=for apidoc Amnh||GV_ADDMULTI
=for apidoc gv_init
The old form of C<gv_init_pvn()>. It does not work with UTF-8 strings, as it
has no flags parameter. If the C<multi> parameter is set, the
C<GV_ADDMULTI> flag will be passed to C<gv_init_pvn()>.
=for apidoc gv_init_pv
Same as C<gv_init_pvn()>, but takes a nul-terminated string for the name
instead of separate char * and length parameters.
=for apidoc gv_init_sv
Same as C<gv_init_pvn()>, but takes an SV * for the name instead of separate
char * and length parameters. C<flags> is currently unused.
=cut
*/
void
Perl_gv_init_sv(pTHX_ GV *gv, HV *stash, SV* namesv, U32 flags)
{
char *namepv;
STRLEN namelen;
PERL_ARGS_ASSERT_GV_INIT_SV;
namepv = SvPV(namesv, namelen);
if (SvUTF8(namesv))
flags |= SVf_UTF8;
gv_init_pvn(gv, stash, namepv, namelen, flags);
}
void
Perl_gv_init_pv(pTHX_ GV *gv, HV *stash, const char *name, U32 flags)
{
PERL_ARGS_ASSERT_GV_INIT_PV;
gv_init_pvn(gv, stash, name, strlen(name), flags);
}
/* Packages in the symbol table are "stashes" - hashes where the keys are symbol
names and the values are typeglobs. The value $foo::bar is actually found
by looking up the typeglob *foo::{bar} and then reading its SCALAR slot.
At least, that's what you see in Perl space if you use typeglob syntax.
Usually it's also what's actually stored in the stash, but for some cases
different values are stored (as a space optimisation) and converted to full
typeglobs "on demand" - if a typeglob syntax is used to read a value. It's
the job of this function, Perl_gv_init_pvn(), to undo any trickery and
replace the SV stored in the stash with the regular PVGV structure that it is
a shorthand for. This has to be done "in-place" by upgrading the actual SV
that is already stored in the stash to a PVGV.
As the public documentation above says:
Converting any scalar that is C<SvOK()> may produce unpredictable
results and is reserved for perl's internal use.
Values that can be stored:
* plain scalar - a subroutine declaration
The scalar's string value is the subroutine prototype; the integer -1 is
"no prototype". ie shorthand for sub foo ($$); or sub bar;
* reference to a scalar - a constant. ie shorthand for sub PI() { 4; }
* reference to a sub - a subroutine (avoids allocating a PVGV)
The earliest optimisation was subroutine declarations, implemented in 1998
by commit 8472ac73d6d80294:
"Sub declaration cost reduced from ~500 to ~100 bytes"
This space optimisation needs to be invisible to regular Perl code. For this
code:
sub foo ($$);
*foo = [];
When the first line is compiled, the optimisation is used, and $::{foo} is
assigned the scalar '$$'. No PVGV or PVCV is created.
When the second line encountered, the typeglob lookup on foo needs to
"upgrade" the symbol table entry to a PVGV, and then create a PVCV in the
{CODE} slot with the prototype $$ and no body. The typeglob is then available
so that [] can be assigned to the {ARRAY} slot. For the code above the
upgrade happens at compile time, the assignment at runtime.
Analogous code unwinds the other optimisations.
*/
void
Perl_gv_init_pvn(pTHX_ GV *gv, HV *stash, const char *name, STRLEN len, U32 flags)
{
const U32 old_type = SvTYPE(gv);
const bool doproto = old_type > SVt_NULL;
char * const proto = (doproto && SvPOK(gv))
? ((void)(SvIsCOW(gv) && (sv_force_normal((SV *)gv), 0)), SvPVX(gv))
: NULL;
const STRLEN protolen = proto ? SvCUR(gv) : 0;
const U32 proto_utf8 = proto ? SvUTF8(gv) : 0;
SV *const has_constant = doproto && SvROK(gv) ? SvRV(gv) : NULL;
const U32 exported_constant = has_constant ? SvPCS_IMPORTED(gv) : 0;
const bool really_sub =
has_constant && SvTYPE(has_constant) == SVt_PVCV;
COP * const old = PL_curcop;
PERL_ARGS_ASSERT_GV_INIT_PVN;
assert (!(proto && has_constant));
if (has_constant) {
/* The constant has to be a scalar, array or subroutine. */
switch (SvTYPE(has_constant)) {
case SVt_PVHV:
case SVt_PVFM:
case SVt_PVIO:
Perl_croak(aTHX_ "Cannot convert a reference to %s to typeglob",
sv_reftype(has_constant, 0));
NOT_REACHED; /* NOTREACHED */
break;
default: NOOP;
}
SvRV_set(gv, NULL);
SvROK_off(gv);
}
if (old_type < SVt_PVGV) {
if (old_type >= SVt_PV)
SvCUR_set(gv, 0);
sv_upgrade(MUTABLE_SV(gv), SVt_PVGV);
}
if (SvLEN(gv)) {
if (proto) {
/* For this case, we are "stealing" the buffer from the SvPV and
re-attaching to an SV below with the call to sv_usepvn_flags().
Hence we don't free it. */
SvPV_set(gv, NULL);
}
else {
/* There is no valid prototype. (SvPOK() must be true for a valid
prototype.) Hence we free the memory. */
Safefree(SvPVX_mutable(gv));
}
SvLEN_set(gv, 0);
SvPOK_off(gv);
}
SvIOK_off(gv);
isGV_with_GP_on(gv);
if (really_sub && !CvISXSUB(has_constant) && CvSTART(has_constant)
&& ( CvSTART(has_constant)->op_type == OP_NEXTSTATE
|| CvSTART(has_constant)->op_type == OP_DBSTATE))
PL_curcop = (COP *)CvSTART(has_constant);
GvGP_set(gv, Perl_newGP(aTHX_ gv));
PL_curcop = old;
GvSTASH(gv) = stash;
if (stash)
Perl_sv_add_backref(aTHX_ MUTABLE_SV(stash), MUTABLE_SV(gv));
gv_name_set(gv, name, len, GV_ADD | ( flags & SVf_UTF8 ? SVf_UTF8 : 0 ));
if (flags & GV_ADDMULTI || doproto) /* doproto means it */
GvMULTI_on(gv); /* _was_ mentioned */
if (really_sub) {
/* Not actually a constant. Just a regular sub. */
CV * const cv = (CV *)has_constant;
GvCV_set(gv,cv);
if (CvNAMED(cv) && CvSTASH(cv) == stash && (
CvNAME_HEK(cv) == GvNAME_HEK(gv)
|| ( HEK_LEN(CvNAME_HEK(cv)) == HEK_LEN(GvNAME_HEK(gv))
&& HEK_FLAGS(CvNAME_HEK(cv)) != HEK_FLAGS(GvNAME_HEK(gv))
&& HEK_UTF8(CvNAME_HEK(cv)) == HEK_UTF8(GvNAME_HEK(gv))
&& memEQ(HEK_KEY(CvNAME_HEK(cv)), GvNAME(gv), GvNAMELEN(gv))
)
))
CvGV_set(cv,gv);
}
else if (doproto) {
CV *cv;
if (has_constant) {
/* newCONSTSUB takes ownership of the reference from us. */
cv = newCONSTSUB_flags(stash, name, len, flags, has_constant);
/* In case op.c:S_process_special_blocks stole it: */
if (!GvCV(gv))
GvCV_set(gv, (CV *)SvREFCNT_inc_simple_NN(cv));
assert(GvCV(gv) == cv); /* newCONSTSUB should have set this */
/* If this reference was a copy of another, then the subroutine
must have been "imported", by a Perl space assignment to a GV
from a reference to CV. */
if (exported_constant)
GvIMPORTED_CV_on(gv);
CvSTASH_set(cv, PL_curstash); /* XXX Why is this needed? */
} else {
cv = newSTUB(gv,1);
}
if (proto) {
sv_usepvn_flags(MUTABLE_SV(cv), proto, protolen,
SV_HAS_TRAILING_NUL);
if ( proto_utf8 ) SvUTF8_on(MUTABLE_SV(cv));
}
}
}
STATIC void
S_gv_init_svtype(pTHX_ GV *gv, const svtype sv_type)
{
PERL_ARGS_ASSERT_GV_INIT_SVTYPE;
switch (sv_type) {
case SVt_PVIO:
(void)GvIOn(gv);
break;
case SVt_PVAV:
(void)GvAVn(gv);
break;
case SVt_PVHV:
(void)GvHVn(gv);
break;
#ifdef PERL_DONT_CREATE_GVSV
case SVt_NULL:
case SVt_PVCV:
case SVt_PVFM:
case SVt_PVGV:
break;
default:
if(GvSVn(gv)) {
/* Work round what appears to be a bug in Sun C++ 5.8 2005/10/13
If we just cast GvSVn(gv) to void, it ignores evaluating it for
its side effect */
}
#endif
}
}
static void core_xsub(pTHX_ CV* cv);
static GV *
S_maybe_add_coresub(pTHX_ HV * const stash, GV *gv,
const char * const name, const STRLEN len)
{
const int code = keyword(name, len, 1);
static const char file[] = __FILE__;
CV *cv, *oldcompcv = NULL;
int opnum = 0;
bool ampable = TRUE; /* &{}-able */
COP *oldcurcop = NULL;
yy_parser *oldparser = NULL;
I32 oldsavestack_ix = 0;
assert(gv || stash);
assert(name);
if (!code) return NULL; /* Not a keyword */
switch (code < 0 ? -code : code) {
/* no support for \&CORE::infix;
no support for funcs that do not parse like funcs */
case KEY___DATA__: case KEY___END__ :
case KEY_ADJUST : case KEY_AUTOLOAD: case KEY_BEGIN : case KEY_CHECK :
case KEY_DESTROY : case KEY_END : case KEY_INIT : case KEY_UNITCHECK:
case KEY_and : case KEY_catch : case KEY_class :
case KEY_cmp : case KEY_default: case KEY_defer :
case KEY_do : case KEY_dump : case KEY_else : case KEY_elsif :
case KEY_eq : case KEY_eval : case KEY_field :
case KEY_finally:
case KEY_for : case KEY_foreach: case KEY_format: case KEY_ge :
case KEY_given : case KEY_goto : case KEY_grep : case KEY_gt :
case KEY_if : case KEY_isa :
case KEY_last :
case KEY_le : case KEY_local : case KEY_lt : case KEY_m :
case KEY_map : case KEY_method : case KEY_my :
case KEY_ne : case KEY_next : case KEY_no: case KEY_or: case KEY_our:
case KEY_package: case KEY_print: case KEY_printf:
case KEY_q : case KEY_qq : case KEY_qr : case KEY_qw :
case KEY_qx : case KEY_redo : case KEY_require: case KEY_return:
case KEY_s : case KEY_say : case KEY_sort :
case KEY_state: case KEY_sub :
case KEY_tr : case KEY_try :
case KEY_unless:
case KEY_until: case KEY_use : case KEY_when : case KEY_while :
case KEY_x : case KEY_xor : case KEY_y :
return NULL;
case KEY_chdir:
case KEY_chomp: case KEY_chop: case KEY_defined: case KEY_delete:
case KEY_eof : case KEY_exec: case KEY_exists :
case KEY_lstat:
case KEY_split:
case KEY_stat:
case KEY_system:
case KEY_truncate: case KEY_unlink:
ampable = FALSE;
}
if (!gv) {
gv = (GV *)newSV_type(SVt_NULL);
gv_init(gv, stash, name, len, TRUE);
}
GvMULTI_on(gv);
if (ampable) {
ENTER;
oldcurcop = PL_curcop;
oldparser = PL_parser;
lex_start(NULL, NULL, 0);
oldcompcv = PL_compcv;
PL_compcv = NULL; /* Prevent start_subparse from setting
CvOUTSIDE. */
oldsavestack_ix = start_subparse(FALSE,0);
cv = PL_compcv;
}
else {
/* Avoid calling newXS, as it calls us, and things start to
get hairy. */
cv = MUTABLE_CV(newSV_type(SVt_PVCV));
GvCV_set(gv,cv);
GvCVGEN(gv) = 0;
CvISXSUB_on(cv);
CvXSUB(cv) = core_xsub;
PoisonPADLIST(cv);
}
CvGV_set(cv, gv); /* This stops new ATTRSUB from setting CvFILE
from PL_curcop. */
/* XSUBs can't be perl lang/perl5db.pl debugged
if (PERLDB_LINE_OR_SAVESRC)
(void)gv_fetchfile(file); */
CvFILE(cv) = (char *)file;
/* XXX This is inefficient, as doing things this order causes
a prototype check in newATTRSUB. But we have to do
it this order as we need an op number before calling
new ATTRSUB. */
(void)core_prototype((SV *)cv, name, code, &opnum);
if (stash)
(void)hv_store(stash,name,len,(SV *)gv,0);
if (ampable) {
#ifdef DEBUGGING
CV *orig_cv = cv;
#endif
CvLVALUE_on(cv);
/* newATTRSUB will free the CV and return NULL if we're still
compiling after a syntax error */
if ((cv = newATTRSUB_x(
oldsavestack_ix, (OP *)gv,
NULL,NULL,
coresub_op(
opnum
? newSVuv((UV)opnum)
: newSVpvn(name,len),
code, opnum
),
TRUE
)) != NULL) {
assert(GvCV(gv) == orig_cv);
if (opnum != OP_VEC && opnum != OP_SUBSTR && opnum != OP_POS
&& opnum != OP_UNDEF && opnum != OP_KEYS)
CvLVALUE_off(cv); /* Now *that* was a neat trick. */
}
LEAVE;
PL_parser = oldparser;
PL_curcop = oldcurcop;
PL_compcv = oldcompcv;
}
if (cv) {
SV *opnumsv = newSViv(
(opnum == OP_ENTEREVAL && len == 9 && memEQ(name, "evalbytes", 9)) ?
(OP_ENTEREVAL | (1<<16))
: opnum ? opnum : (((I32)name[2]) << 16));
cv_set_call_checker_flags(cv, Perl_ck_entersub_args_core, opnumsv, 0);
SvREFCNT_dec_NN(opnumsv);
}
return gv;
}
/*
=for apidoc gv_fetchmeth
=for apidoc_item gv_fetchmeth_pv
=for apidoc_item gv_fetchmeth_pvn
=for apidoc_item gv_fetchmeth_sv
These each look for a glob with name C<name>, containing a defined subroutine,
returning the GV of that glob if found, or C<NULL> if not.
C<stash> is always searched (first), unless it is C<NULL>.
If C<stash> is NULL, or was searched but nothing was found in it, and the
C<GV_SUPER> bit is set in C<flags>, stashes accessible via C<@ISA> are searched
next. Searching is conducted according to L<C<MRO> order|perlmroapi>.
Finally, if no matches were found so far, and the C<GV_NOUNIVERSAL> flag in
C<flags> is not set, C<UNIVERSAL::> is searched.
The argument C<level> should be either 0 or -1. If -1, the function will
return without any side effects or caching. If 0, the function makes sure
there is a glob named C<name> in C<stash>, creating one if necessary.
The subroutine slot in the glob will be set to any subroutine found in the
C<stash> and C<SUPER::> search, hence caching any C<SUPER::> result. Note that
subroutines found in C<UNIVERSAL::> are not cached.
The GV returned from these may be a method cache entry, which is not visible to
Perl code. So when calling C<call_sv>, you should not use the GV directly;
instead, you should use the method's CV, which can be obtained from the GV with
the C<GvCV> macro.
The only other significant value for C<flags> is C<SVf_UTF8>, indicating that
C<name> is to be treated as being encoded in UTF-8.
Plain C<gv_fetchmeth> lacks a C<flags> parameter, hence always searches in
C<stash>, then C<UNIVERSAL::>, and C<name> is never UTF-8. Otherwise it is
exactly like C<gv_fetchmeth_pvn>.
The other forms do have a C<flags> parameter, and differ only in how the glob
name is specified.
In C<gv_fetchmeth_pv>, C<name> is a C language NUL-terminated string.
In C<gv_fetchmeth_pvn>, C<name> points to the first byte of the name, and an
additional parameter, C<len>, specifies its length in bytes. Hence, the name
may contain embedded-NUL characters.
In C<gv_fetchmeth_sv>, C<*name> is an SV, and the name is the PV extracted from
that, using L</C<SvPV>>. If the SV is marked as being in UTF-8, the extracted
PV will also be.
=for apidoc Amnh||GV_SUPER
=cut
*/
GV *
Perl_gv_fetchmeth_sv(pTHX_ HV *stash, SV *namesv, I32 level, U32 flags)
{
char *namepv;
STRLEN namelen;
PERL_ARGS_ASSERT_GV_FETCHMETH_SV;
if (LIKELY(SvPOK_nog(namesv))) /* common case */
return gv_fetchmeth_internal(stash, namesv, NULL, 0, level,
flags | SvUTF8(namesv));
namepv = SvPV(namesv, namelen);
if (SvUTF8(namesv)) flags |= SVf_UTF8;
return gv_fetchmeth_pvn(stash, namepv, namelen, level, flags);
}
GV *
Perl_gv_fetchmeth_pv(pTHX_ HV *stash, const char *name, I32 level, U32 flags)
{
PERL_ARGS_ASSERT_GV_FETCHMETH_PV;
return gv_fetchmeth_internal(stash, NULL, name, strlen(name), level, flags);
}
/* NOTE: No support for tied ISA */
PERL_STATIC_INLINE GV*
S_gv_fetchmeth_internal(pTHX_ HV* stash, SV* meth, const char* name, STRLEN len, I32 level, U32 flags)
{
GV** gvp;
HE* he;
AV* linear_av;
SV** linear_svp;
SV* linear_sv;
HV* cstash, *cachestash;
GV* candidate = NULL;
CV* cand_cv = NULL;
GV* topgv = NULL;
const char *hvname;
STRLEN hvnamelen;
I32 create = (level >= 0) ? HV_FETCH_LVALUE : 0;
I32 items;
U32 topgen_cmp;
U32 is_utf8 = flags & SVf_UTF8;
/* UNIVERSAL methods should be callable without a stash */
if (!stash) {
create = 0; /* probably appropriate */
if(!(stash = gv_stashpvs("UNIVERSAL", 0)))
return 0;
}
assert(stash);
hvname = HvNAME_get(stash);
hvnamelen = HvNAMELEN_get(stash);
if (!hvname)
Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup");
assert(hvname);
assert(name || meth);
DEBUG_o( Perl_deb(aTHX_ "Looking for %smethod %s in package %s\n",
flags & GV_SUPER ? "SUPER " : "",
name ? name : SvPV_nolen(meth), hvname) );
topgen_cmp = HvMROMETA(stash)->cache_gen + PL_sub_generation;
if (flags & GV_SUPER) {
if (!HvAUX(stash)->xhv_mro_meta->super)
HvAUX(stash)->xhv_mro_meta->super = newHV();
cachestash = HvAUX(stash)->xhv_mro_meta->super;
}
else cachestash = stash;
/* check locally for a real method or a cache entry */
he = (HE*)hv_common(
cachestash, meth, name, len, is_utf8 ? HVhek_UTF8 : 0, create, NULL, 0
);
if (he) gvp = (GV**)&HeVAL(he);
else gvp = NULL;
if(gvp) {
topgv = *gvp;
have_gv:
assert(topgv);
if (SvTYPE(topgv) != SVt_PVGV)
{
if (!name)
name = SvPV_nomg(meth, len);
gv_init_pvn(topgv, stash, name, len, GV_ADDMULTI|is_utf8);
}
if ((cand_cv = GvCV(topgv))) {
/* If genuine method or valid cache entry, use it */
if (!GvCVGEN(topgv) || GvCVGEN(topgv) == topgen_cmp) {
return topgv;
}
else {
/* stale cache entry, junk it and move on */
SvREFCNT_dec_NN(cand_cv);
GvCV_set(topgv, NULL);
cand_cv = NULL;
GvCVGEN(topgv) = 0;
}
}
else if (GvCVGEN(topgv) == topgen_cmp) {
/* cache indicates no such method definitively */
return 0;
}
else if (stash == cachestash
&& len > 1 /* shortest is uc */
&& memEQs(hvname, HvNAMELEN_get(stash), "CORE")
&& S_maybe_add_coresub(aTHX_ NULL,topgv,name,len))
goto have_gv;
}
linear_av = mro_get_linear_isa(stash); /* has ourselves at the top of the list */
linear_svp = AvARRAY(linear_av) + 1; /* skip over self */
items = AvFILLp(linear_av); /* no +1, to skip over self */
while (items--) {
linear_sv = *linear_svp++;
assert(linear_sv);
cstash = gv_stashsv(linear_sv, 0);
if (!cstash) {
if ( ckWARN(WARN_SYNTAX)) {
if( /* these are loaded from Perl_Gv_AMupdate() one way or another */
( len && name[0] == '(' ) /* overload.pm related, in particular "()" */
|| ( memEQs( name, len, "DESTROY") )
) {
Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
"Can't locate package %" SVf " for @%" HEKf "::ISA",
SVfARG(linear_sv),
HEKfARG(HvNAME_HEK(stash)));
} else if( memEQs( name, len, "AUTOLOAD") ) {
/* gobble this warning */
} else {
Perl_ck_warner(aTHX_ packWARN(WARN_SYNTAX),
"While trying to resolve method call %.*s->%.*s()"
" can not locate package %" SVf_QUOTEDPREFIX " yet it is mentioned in @%.*s::ISA"
" (perhaps you forgot to load %" SVf_QUOTEDPREFIX "?)",
(int) hvnamelen, hvname,
(int) len, name,
SVfARG(linear_sv),
(int) hvnamelen, hvname,
SVfARG(linear_sv));
}
}
continue;
}
assert(cstash);
gvp = (GV**)hv_common(
cstash, meth, name, len, is_utf8 ? HVhek_UTF8 : 0, HV_FETCH_JUST_SV, NULL, 0
);
if (!gvp) {
if (len > 1 && HvNAMELEN_get(cstash) == 4) {
const char *hvname = HvNAME(cstash); assert(hvname);
if (strBEGINs(hvname, "CORE")
&& (candidate =
S_maybe_add_coresub(aTHX_ cstash,NULL,name,len)
))
goto have_candidate;
}
continue;
}
else candidate = *gvp;
have_candidate:
assert(candidate);
if (SvTYPE(candidate) != SVt_PVGV)
gv_init_pvn(candidate, cstash, name, len, GV_ADDMULTI|is_utf8);
if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) {
/*
* Found real method, cache method in topgv if:
* 1. topgv has no synonyms (else inheritance crosses wires)
* 2. method isn't a stub (else AUTOLOAD fails spectacularly)
*/
if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
CV *old_cv = GvCV(topgv);
SvREFCNT_dec(old_cv);
SvREFCNT_inc_simple_void_NN(cand_cv);
GvCV_set(topgv, cand_cv);
GvCVGEN(topgv) = topgen_cmp;
}
return candidate;
}
}
/* Check UNIVERSAL without caching */
if((level == 0 || level == -1) && !(flags & GV_NOUNIVERSAL)) {
candidate = gv_fetchmeth_internal(NULL, meth, name, len, 1,
flags &~GV_SUPER);
if(candidate) {
cand_cv = GvCV(candidate);
if (topgv && (GvREFCNT(topgv) == 1) && (CvROOT(cand_cv) || CvXSUB(cand_cv))) {
CV *old_cv = GvCV(topgv);
SvREFCNT_dec(old_cv);
SvREFCNT_inc_simple_void_NN(cand_cv);
GvCV_set(topgv, cand_cv);
GvCVGEN(topgv) = topgen_cmp;
}
return candidate;
}
}
if (topgv && GvREFCNT(topgv) == 1 && !(flags & GV_NOUNIVERSAL)) {
/* cache the fact that the method is not defined */
GvCVGEN(topgv) = topgen_cmp;
}
return 0;
}
GV *
Perl_gv_fetchmeth_pvn(pTHX_ HV *stash, const char *name, STRLEN len, I32 level, U32 flags)
{
PERL_ARGS_ASSERT_GV_FETCHMETH_PVN;
return gv_fetchmeth_internal(stash, NULL, name, len, level, flags);
}
/*
=for apidoc gv_fetchmeth_autoload
This is the old form of L</gv_fetchmeth_pvn_autoload>, which has no flags