[perl5.git] / cv.h

/*    cv.h
 *
 *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
 *    2002, 2003, 2004, 2005, 2006, 2007, 2008 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.
 *
 */

/* This structure must match the beginning of XPVFM in sv.h  */

struct xpvcv {
    _XPV_HEAD;
    _XPVCV_COMMON;
};

/*
=head1 Handy Values

=for apidoc AmU||Nullcv
Null CV pointer.

(deprecated - use C<(CV *)NULL> instead)

=head1 CV Manipulation Functions

This section documents functions to manipulate CVs which are code-values,
or subroutines. For more information, see L<perlguts>.

=for apidoc Am|HV*|CvSTASH|CV* cv
Returns the stash of the CV. A stash is the symbol table hash, containing
the package-scoped variables in the package where the subroutine was defined.
For more information, see L<perlguts>.

This also has a special use with XS AUTOLOAD subs.
See L<perlguts/Autoloading with XSUBs>.

=cut
*/

#ifndef PERL_CORE
#  define Nullcv Null(CV*)
#endif

#define CvSTASH(sv)	(0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash)
#define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st)
#define CvSTART(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start
#define CvROOT(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root
#define CvXSUB(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub
#define CvXSUBANY(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany
#define CvGV(sv)	S_CvGV((CV *)(sv))
#define CvGV_set(cv,gv)	Perl_cvgv_set(aTHX_ cv, gv)
#define CvFILE(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
#ifdef USE_ITHREADS
#  define CvFILE_set_from_cop(sv, cop)	\
    (CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv))
#else
#  define CvFILE_set_from_cop(sv, cop)	\
    (CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv))
#endif
#define CvFILEGV(sv)	(gv_fetchfile(CvFILE(sv)))
#define CvDEPTH(sv)	(*S_CvDEPTHp((const CV *)sv))
#define CvPADLIST(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist
#define CvOUTSIDE(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside
#define CvFLAGS(sv)	((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags
#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq

/* These two are sometimes called on non-CVs */
#define CvPROTO(sv)                               \
	(                                          \
	 SvPOK(sv)                                  \
	  ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
	     ? SvEND(sv)+1 : SvPVX_const(sv)          \
	  : NULL                                       \
	)
#define CvPROTOLEN(sv)	                          \
	(                                          \
	 SvPOK(sv)                                  \
	  ? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
	     ? SvLEN(sv)-SvCUR(sv)-2                  \
	     : SvCUR(sv)                               \
	  : 0                                           \
	)

#define CVf_METHOD	0x0001	/* CV is explicitly marked as a method */
#define CVf_LVALUE	0x0002  /* CV return value can be used as lvalue */
#define CVf_CONST	0x0004  /* inlinable sub */
#define CVf_ISXSUB	0x0008	/* CV is an XSUB, not pure perl.  */

#define CVf_WEAKOUTSIDE	0x0010  /* CvOUTSIDE isn't ref counted */
#define CVf_CLONE	0x0020	/* anon CV uses external lexicals */
#define CVf_CLONED	0x0040	/* a clone of one of those */
#define CVf_ANON	0x0080	/* CV is not pointed to by a GV */
#define CVf_UNIQUE	0x0100	/* sub is only called once (eg PL_main_cv,
				 * require, eval). */
#define CVf_NODEBUG	0x0200	/* no DB::sub indirection for this CV
				   (esp. useful for special XSUBs) */
#define CVf_CVGV_RC	0x0400	/* CvGV is reference counted */
#ifdef PERL_CORE
# define CVf_SLABBED	0x0800	/* Holds refcount on op slab  */
#endif
#define CVf_DYNFILE	0x1000	/* The filename isn't static  */
#define CVf_AUTOLOAD	0x2000	/* SvPVX contains AUTOLOADed sub name  */
#define CVf_HASEVAL	0x4000	/* contains string eval  */
#define CVf_NAMED	0x8000  /* Has a name HEK */

/* This symbol for optimised communication between toke.c and op.c: */
#define CVf_BUILTIN_ATTRS	(CVf_METHOD|CVf_LVALUE)

#define CvCLONE(cv)		(CvFLAGS(cv) & CVf_CLONE)
#define CvCLONE_on(cv)		(CvFLAGS(cv) |= CVf_CLONE)
#define CvCLONE_off(cv)		(CvFLAGS(cv) &= ~CVf_CLONE)

#define CvCLONED(cv)		(CvFLAGS(cv) & CVf_CLONED)
#define CvCLONED_on(cv)		(CvFLAGS(cv) |= CVf_CLONED)
#define CvCLONED_off(cv)	(CvFLAGS(cv) &= ~CVf_CLONED)

#define CvANON(cv)		(CvFLAGS(cv) & CVf_ANON)
#define CvANON_on(cv)		(CvFLAGS(cv) |= CVf_ANON)
#define CvANON_off(cv)		(CvFLAGS(cv) &= ~CVf_ANON)

/* CvEVAL or CvSPECIAL */
#define CvUNIQUE(cv)		(CvFLAGS(cv) & CVf_UNIQUE)
#define CvUNIQUE_on(cv)		(CvFLAGS(cv) |= CVf_UNIQUE)
#define CvUNIQUE_off(cv)	(CvFLAGS(cv) &= ~CVf_UNIQUE)

#define CvNODEBUG(cv)		(CvFLAGS(cv) & CVf_NODEBUG)
#define CvNODEBUG_on(cv)	(CvFLAGS(cv) |= CVf_NODEBUG)
#define CvNODEBUG_off(cv)	(CvFLAGS(cv) &= ~CVf_NODEBUG)

#define CvMETHOD(cv)		(CvFLAGS(cv) & CVf_METHOD)
#define CvMETHOD_on(cv)		(CvFLAGS(cv) |= CVf_METHOD)
#define CvMETHOD_off(cv)	(CvFLAGS(cv) &= ~CVf_METHOD)

#define CvLVALUE(cv)		(CvFLAGS(cv) & CVf_LVALUE)
#define CvLVALUE_on(cv)		(CvFLAGS(cv) |= CVf_LVALUE)
#define CvLVALUE_off(cv)	(CvFLAGS(cv) &= ~CVf_LVALUE)

/* eval or PL_main_cv */
#define CvEVAL(cv)		(CvUNIQUE(cv) && !SvFAKE(cv))
#define CvEVAL_on(cv)		(CvUNIQUE_on(cv),SvFAKE_off(cv))
#define CvEVAL_off(cv)		CvUNIQUE_off(cv)

/* BEGIN|CHECK|INIT|UNITCHECK|END */
#define CvSPECIAL(cv)		(CvUNIQUE(cv) && SvFAKE(cv))
#define CvSPECIAL_on(cv)	(CvUNIQUE_on(cv),SvFAKE_on(cv))
#define CvSPECIAL_off(cv)	(CvUNIQUE_off(cv),SvFAKE_off(cv))

#define CvCONST(cv)		(CvFLAGS(cv) & CVf_CONST)
#define CvCONST_on(cv)		(CvFLAGS(cv) |= CVf_CONST)
#define CvCONST_off(cv)		(CvFLAGS(cv) &= ~CVf_CONST)

#define CvWEAKOUTSIDE(cv)	(CvFLAGS(cv) & CVf_WEAKOUTSIDE)
#define CvWEAKOUTSIDE_on(cv)	(CvFLAGS(cv) |= CVf_WEAKOUTSIDE)
#define CvWEAKOUTSIDE_off(cv)	(CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)

#define CvISXSUB(cv)		(CvFLAGS(cv) & CVf_ISXSUB)
#define CvISXSUB_on(cv)		(CvFLAGS(cv) |= CVf_ISXSUB)
#define CvISXSUB_off(cv)	(CvFLAGS(cv) &= ~CVf_ISXSUB)

#define CvCVGV_RC(cv)		(CvFLAGS(cv) & CVf_CVGV_RC)
#define CvCVGV_RC_on(cv)	(CvFLAGS(cv) |= CVf_CVGV_RC)
#define CvCVGV_RC_off(cv)	(CvFLAGS(cv) &= ~CVf_CVGV_RC)

#ifdef PERL_CORE
# define CvSLABBED(cv)		(CvFLAGS(cv) & CVf_SLABBED)
# define CvSLABBED_on(cv)	(CvFLAGS(cv) |= CVf_SLABBED)
# define CvSLABBED_off(cv)	(CvFLAGS(cv) &= ~CVf_SLABBED)
#endif

#define CvDYNFILE(cv)		(CvFLAGS(cv) & CVf_DYNFILE)
#define CvDYNFILE_on(cv)	(CvFLAGS(cv) |= CVf_DYNFILE)
#define CvDYNFILE_off(cv)	(CvFLAGS(cv) &= ~CVf_DYNFILE)

#define CvAUTOLOAD(cv)		(CvFLAGS(cv) & CVf_AUTOLOAD)
#define CvAUTOLOAD_on(cv)	(CvFLAGS(cv) |= CVf_AUTOLOAD)
#define CvAUTOLOAD_off(cv)	(CvFLAGS(cv) &= ~CVf_AUTOLOAD)

#define CvHASEVAL(cv)		(CvFLAGS(cv) & CVf_HASEVAL)
#define CvHASEVAL_on(cv)	(CvFLAGS(cv) |= CVf_HASEVAL)
#define CvHASEVAL_off(cv)	(CvFLAGS(cv) &= ~CVf_HASEVAL)

#define CvNAMED(cv)		(CvFLAGS(cv) & CVf_NAMED)
#define CvNAMED_on(cv)		(CvFLAGS(cv) |= CVf_NAMED)
#define CvNAMED_off(cv)		(CvFLAGS(cv) &= ~CVf_NAMED)

/* Flags for newXS_flags  */
#define XS_DYNAMIC_FILENAME	0x01	/* The filename isn't static  */

PERL_STATIC_INLINE GV *
S_CvGV(CV *sv)
{
    return CvNAMED(sv)
	? 0
	: ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_gv;
}
PERL_STATIC_INLINE HEK *
CvNAME_HEK(CV *sv)
{
    return CvNAMED(sv)
	? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek
	: 0;
}
/* This lowers the refernce count of the previous value, but does *not*
   increment the reference count of the new value. */
#define CvNAME_HEK_set(cv, hek) ( \
	CvNAME_HEK((CV *)(cv))						 \
	    ? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek)	  \
	    : (void)0,						   \
	((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \
	CvNAMED_on(cv)						     \
    )

/*
=head1 CV reference counts and CvOUTSIDE

=for apidoc m|bool|CvWEAKOUTSIDE|CV *cv

Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
CV (if any). Because pointers to anonymous sub prototypes are
stored in C<&> pad slots, it is a possible to get a circular reference,
with the parent pointing to the child and vice-versa. To avoid the
ensuing memory leak, we do not increment the reference count of the CV
pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
has a C<&> pad slot pointing back to us. In this case, we set the
C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
circumstances we should decrement the refcount of the parent when freeing
the child.

There is a further complication with non-closure anonymous subs (i.e. those
that do not refer to any lexicals outside that sub). In this case, the
anonymous prototype is shared rather than being cloned. This has the
consequence that the parent may be freed while there are still active
children, eg

    BEGIN { $a = sub { eval '$x' } }

In this case, the BEGIN is freed immediately after execution since there
are no active references to it: the anon sub prototype has
C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
CV, so it doesn't contribute to BEGIN's refcount either.  When $a is
executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
and the freed BEGIN is accessed.

To avoid this, whenever a CV and its associated pad is freed, any
C<&> entries in the pad are explicitly removed from the pad, and if the
refcount of the pointed-to anon sub is still positive, then that
child's C<CvOUTSIDE> is set to point to its grandparent. This will only
occur in the single specific case of a non-closure anon prototype
having one or more active references (such as C<$a> above).

One other thing to consider is that a CV may be merely undefined
rather than freed, eg C<undef &foo>. In this case, its refcount may
not have reached zero, but we still delete its pad and its C<CvROOT> etc.
Since various children may still have their C<CvOUTSIDE> pointing at this
undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
the chain of lexical scopes is unbroken. For example, the following
should print 123:

    my $x = 123;
    sub tmp { sub { eval '$x' } }
    my $a = tmp();
    undef &tmp;
    print  $a->();

=cut
*/

typedef OP *(*Perl_call_checker)(pTHX_ OP *, GV *, SV *);

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set ts=8 sts=4 sw=4 et:
 */
Commit	Line	Data
a0d0e21e	1	/* cv.h
79072805	2	*
1129b882 NC	3	* Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
1129b882 NC	4	* 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
79072805 LW	5	*
	6	* You may distribute under the terms of either the GNU General Public
	7	* License or the Artistic License, as specified in the README file.
	8	*
79072805 LW	9	*/
79072805 LW	10
f653aab7	11	/* This structure must match the beginning of XPVFM in sv.h */
44a8e56a	12
79072805	13	struct xpvcv {
20f4945e	14	_XPV_HEAD;
20f4945e	15	_XPVCV_COMMON;
79072805	16	};
748a9306	17
954c1994	18	/*
ccfc67b7 JH	19	=head1 Handy Values
ccfc67b7 JH	20
954c1994 GS	21	=for apidoc AmU\|\|Nullcv
	22	Null CV pointer.
	23
3ae1b226 NC	24	(deprecated - use C<(CV *)NULL> instead)
3ae1b226 NC	25
ccfc67b7 JH	26	=head1 CV Manipulation Functions
ccfc67b7 JH	27
f0b90de1 SF	28	This section documents functions to manipulate CVs which are code-values,
	29	or subroutines. For more information, see L<perlguts>.
	30
954c1994	31	=for apidoc Am\|HV\|CvSTASH\|CV cv
f0b90de1 SF	32	Returns the stash of the CV. A stash is the symbol table hash, containing
	33	the package-scoped variables in the package where the subroutine was defined.
	34	For more information, see L<perlguts>.
954c1994	35
5b36e945 FC	36	This also has a special use with XS AUTOLOAD subs.
	37	See L<perlguts/Autoloading with XSUBs>.
	38
954c1994 GS	39	=cut
	40	*/
	41
3ae1b226 NC	42	#ifndef PERL_CORE
	43	# define Nullcv Null(CV*)
	44	#endif
a5f75d66	45
c68d9564 Z	46	#define CvSTASH(sv) (0+((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_stash)
c68d9564 Z	47	#define CvSTASH_set(cv,st) Perl_cvstash_set(aTHX_ cv, st)
8f629a87 NC	48	#define CvSTART(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_start
	49	#define CvROOT(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_root
	50	#define CvXSUB(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_root_u.xcv_xsub
	51	#define CvXSUBANY(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_start_u.xcv_xsubany
b290562e	52	#define CvGV(sv) S_CvGV((CV *)(sv))
b3f91e91	53	#define CvGV_set(cv,gv) Perl_cvgv_set(aTHX_ cv, gv)
8f629a87	54	#define CvFILE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_file
a636914a	55	#ifdef USE_ITHREADS
bad4ae38 FC	56	# define CvFILE_set_from_cop(sv, cop) \
bad4ae38 FC	57	(CvFILE(sv) = savepv(CopFILE(cop)), CvDYNFILE_on(sv))
a636914a	58	#else
bad4ae38 FC	59	# define CvFILE_set_from_cop(sv, cop) \
bad4ae38 FC	60	(CvFILE(sv) = CopFILE(cop), CvDYNFILE_off(sv))
a636914a	61	#endif
9ec2a764	62	#define CvFILEGV(sv) (gv_fetchfile(CvFILE(sv)))
1afe1db1	63	#define CvDEPTH(sv) (S_CvDEPTHp((const CV )sv))
8f629a87 NC	64	#define CvPADLIST(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_padlist
	65	#define CvOUTSIDE(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside
	66	#define CvFLAGS(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_flags
	67	#define CvOUTSIDE_SEQ(sv) ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_outside_seq
a5f75d66	68
8fa6a409 FC	69	/* These two are sometimes called on non-CVs */
	70	#define CvPROTO(sv) \
	71	( \
	72	SvPOK(sv) \
	73	? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
	74	? SvEND(sv)+1 : SvPVX_const(sv) \
	75	: NULL \
	76	)
	77	#define CvPROTOLEN(sv) \
	78	( \
	79	SvPOK(sv) \
	80	? SvTYPE(sv) == SVt_PVCV && CvAUTOLOAD(sv) \
	81	? SvLEN(sv)-SvCUR(sv)-2 \
	82	: SvCUR(sv) \
	83	: 0 \
	84	)
	85
5b4563c8	86	#define CVf_METHOD 0x0001 /* CV is explicitly marked as a method */
c2485e0c NC	87	#define CVf_LVALUE 0x0002 /* CV return value can be used as lvalue */
	88	#define CVf_CONST 0x0004 /* inlinable sub */
	89	#define CVf_ISXSUB 0x0008 /* CV is an XSUB, not pure perl. */
5b4563c8 NC	90
	91	#define CVf_WEAKOUTSIDE 0x0010 /* CvOUTSIDE isn't ref counted */
	92	#define CVf_CLONE 0x0020 /* anon CV uses external lexicals */
	93	#define CVf_CLONED 0x0040 /* a clone of one of those */
cfc1e951	94	#define CVf_ANON 0x0080 /* CV is not pointed to by a GV */
5b4563c8	95	#define CVf_UNIQUE 0x0100 /* sub is only called once (eg PL_main_cv,
1108974d	96	* require, eval). */
5b4563c8	97	#define CVf_NODEBUG 0x0200 /* no DB::sub indirection for this CV
8ebc5c01	98	(esp. useful for special XSUBs) */
cfc1e951	99	#define CVf_CVGV_RC 0x0400 /* CvGV is reference counted */
58aef2b3 FC	100	#ifdef PERL_CORE
	101	# define CVf_SLABBED 0x0800 /* Holds refcount on op slab */
	102	#endif
bad4ae38	103	#define CVf_DYNFILE 0x1000 /* The filename isn't static */
8fa6a409	104	#define CVf_AUTOLOAD 0x2000 /* SvPVX contains AUTOLOADed sub name */
a0d2bbd5	105	#define CVf_HASEVAL 0x4000 /* contains string eval */
b290562e	106	#define CVf_NAMED 0x8000 /* Has a name HEK */
7dafbf52	107
d3cea301	108	/* This symbol for optimised communication between toke.c and op.c: */
e95ab0c0	109	#define CVf_BUILTIN_ATTRS (CVf_METHOD\|CVf_LVALUE)
a5f75d66 AD	110
	111	#define CvCLONE(cv) (CvFLAGS(cv) & CVf_CLONE)
	112	#define CvCLONE_on(cv) (CvFLAGS(cv) \|= CVf_CLONE)
	113	#define CvCLONE_off(cv) (CvFLAGS(cv) &= ~CVf_CLONE)
	114
	115	#define CvCLONED(cv) (CvFLAGS(cv) & CVf_CLONED)
	116	#define CvCLONED_on(cv) (CvFLAGS(cv) \|= CVf_CLONED)
	117	#define CvCLONED_off(cv) (CvFLAGS(cv) &= ~CVf_CLONED)
	118
	119	#define CvANON(cv) (CvFLAGS(cv) & CVf_ANON)
	120	#define CvANON_on(cv) (CvFLAGS(cv) \|= CVf_ANON)
	121	#define CvANON_off(cv) (CvFLAGS(cv) &= ~CVf_ANON)
79072805	122
a2278b6a	123	/* CvEVAL or CvSPECIAL */
07055b4c CS	124	#define CvUNIQUE(cv) (CvFLAGS(cv) & CVf_UNIQUE)
	125	#define CvUNIQUE_on(cv) (CvFLAGS(cv) \|= CVf_UNIQUE)
	126	#define CvUNIQUE_off(cv) (CvFLAGS(cv) &= ~CVf_UNIQUE)
8ebc5c01	127
	128	#define CvNODEBUG(cv) (CvFLAGS(cv) & CVf_NODEBUG)
	129	#define CvNODEBUG_on(cv) (CvFLAGS(cv) \|= CVf_NODEBUG)
	130	#define CvNODEBUG_off(cv) (CvFLAGS(cv) &= ~CVf_NODEBUG)
77a005ab MB	131
	132	#define CvMETHOD(cv) (CvFLAGS(cv) & CVf_METHOD)
	133	#define CvMETHOD_on(cv) (CvFLAGS(cv) \|= CVf_METHOD)
	134	#define CvMETHOD_off(cv) (CvFLAGS(cv) &= ~CVf_METHOD)
	135
cd06dffe GS	136	#define CvLVALUE(cv) (CvFLAGS(cv) & CVf_LVALUE)
	137	#define CvLVALUE_on(cv) (CvFLAGS(cv) \|= CVf_LVALUE)
	138	#define CvLVALUE_off(cv) (CvFLAGS(cv) &= ~CVf_LVALUE)
	139
a2278b6a	140	/* eval or PL_main_cv */
1aff0e91 GS	141	#define CvEVAL(cv) (CvUNIQUE(cv) && !SvFAKE(cv))
	142	#define CvEVAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_off(cv))
	143	#define CvEVAL_off(cv) CvUNIQUE_off(cv)
	144
3c10abe3	145	/* BEGIN\|CHECK\|INIT\|UNITCHECK\|END */
1aff0e91 GS	146	#define CvSPECIAL(cv) (CvUNIQUE(cv) && SvFAKE(cv))
	147	#define CvSPECIAL_on(cv) (CvUNIQUE_on(cv),SvFAKE_on(cv))
	148	#define CvSPECIAL_off(cv) (CvUNIQUE_off(cv),SvFAKE_off(cv))
beab0874 JT	149
	150	#define CvCONST(cv) (CvFLAGS(cv) & CVf_CONST)
	151	#define CvCONST_on(cv) (CvFLAGS(cv) \|= CVf_CONST)
	152	#define CvCONST_off(cv) (CvFLAGS(cv) &= ~CVf_CONST)
a4f1a029	153
7dafbf52 DM	154	#define CvWEAKOUTSIDE(cv) (CvFLAGS(cv) & CVf_WEAKOUTSIDE)
	155	#define CvWEAKOUTSIDE_on(cv) (CvFLAGS(cv) \|= CVf_WEAKOUTSIDE)
	156	#define CvWEAKOUTSIDE_off(cv) (CvFLAGS(cv) &= ~CVf_WEAKOUTSIDE)
	157
d04ba589 NC	158	#define CvISXSUB(cv) (CvFLAGS(cv) & CVf_ISXSUB)
	159	#define CvISXSUB_on(cv) (CvFLAGS(cv) \|= CVf_ISXSUB)
	160	#define CvISXSUB_off(cv) (CvFLAGS(cv) &= ~CVf_ISXSUB)
	161
cfc1e951 DM	162	#define CvCVGV_RC(cv) (CvFLAGS(cv) & CVf_CVGV_RC)
	163	#define CvCVGV_RC_on(cv) (CvFLAGS(cv) \|= CVf_CVGV_RC)
	164	#define CvCVGV_RC_off(cv) (CvFLAGS(cv) &= ~CVf_CVGV_RC)
	165
58aef2b3 FC	166	#ifdef PERL_CORE
	167	# define CvSLABBED(cv) (CvFLAGS(cv) & CVf_SLABBED)
	168	# define CvSLABBED_on(cv) (CvFLAGS(cv) \|= CVf_SLABBED)
	169	# define CvSLABBED_off(cv) (CvFLAGS(cv) &= ~CVf_SLABBED)
	170	#endif
	171
bad4ae38 FC	172	#define CvDYNFILE(cv) (CvFLAGS(cv) & CVf_DYNFILE)
	173	#define CvDYNFILE_on(cv) (CvFLAGS(cv) \|= CVf_DYNFILE)
	174	#define CvDYNFILE_off(cv) (CvFLAGS(cv) &= ~CVf_DYNFILE)
	175
8fa6a409 FC	176	#define CvAUTOLOAD(cv) (CvFLAGS(cv) & CVf_AUTOLOAD)
	177	#define CvAUTOLOAD_on(cv) (CvFLAGS(cv) \|= CVf_AUTOLOAD)
	178	#define CvAUTOLOAD_off(cv) (CvFLAGS(cv) &= ~CVf_AUTOLOAD)
	179
a0d2bbd5 FC	180	#define CvHASEVAL(cv) (CvFLAGS(cv) & CVf_HASEVAL)
	181	#define CvHASEVAL_on(cv) (CvFLAGS(cv) \|= CVf_HASEVAL)
	182	#define CvHASEVAL_off(cv) (CvFLAGS(cv) &= ~CVf_HASEVAL)
	183
b290562e FC	184	#define CvNAMED(cv) (CvFLAGS(cv) & CVf_NAMED)
	185	#define CvNAMED_on(cv) (CvFLAGS(cv) \|= CVf_NAMED)
	186	#define CvNAMED_off(cv) (CvFLAGS(cv) &= ~CVf_NAMED)
	187
77004dee NC	188	/* Flags for newXS_flags */
	189	#define XS_DYNAMIC_FILENAME 0x01 /* The filename isn't static */
	190
b290562e FC	191	PERL_STATIC_INLINE GV *
	192	S_CvGV(CV *sv)
	193	{
	194	return CvNAMED(sv)
	195	? 0
	196	: ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_gv;
	197	}
	198	PERL_STATIC_INLINE HEK *
	199	CvNAME_HEK(CV *sv)
	200	{
	201	return CvNAMED(sv)
	202	? ((XPVCV*)MUTABLE_PTR(SvANY(sv)))->xcv_gv_u.xcv_hek
	203	: 0;
	204	}
2e800d79 FC	205	/* This lowers the refernce count of the previous value, but does not
	206	increment the reference count of the new value. */
	207	#define CvNAME_HEK_set(cv, hek) ( \
	208	CvNAME_HEK((CV *)(cv)) \
	209	? unshare_hek(SvANY((CV *)(cv))->xcv_gv_u.xcv_hek) \
	210	: (void)0, \
	211	((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_gv_u.xcv_hek = (hek), \
	212	CvNAMED_on(cv) \
	213	)
b290562e	214
7dafbf52 DM	215	/*
	216	=head1 CV reference counts and CvOUTSIDE
	217
	218	=for apidoc m\|bool\|CvWEAKOUTSIDE\|CV *cv
	219
	220	Each CV has a pointer, C<CvOUTSIDE()>, to its lexically enclosing
	221	CV (if any). Because pointers to anonymous sub prototypes are
	222	stored in C<&> pad slots, it is a possible to get a circular reference,
	223	with the parent pointing to the child and vice-versa. To avoid the
	224	ensuing memory leak, we do not increment the reference count of the CV
	225	pointed to by C<CvOUTSIDE> in the I<one specific instance> that the parent
	226	has a C<&> pad slot pointing back to us. In this case, we set the
	227	C<CvWEAKOUTSIDE> flag in the child. This allows us to determine under what
	228	circumstances we should decrement the refcount of the parent when freeing
	229	the child.
	230
eeb8d49e	231	There is a further complication with non-closure anonymous subs (i.e. those
7dafbf52 DM	232	that do not refer to any lexicals outside that sub). In this case, the
	233	anonymous prototype is shared rather than being cloned. This has the
	234	consequence that the parent may be freed while there are still active
	235	children, eg
	236
	237	BEGIN { $a = sub { eval '$x' } }
	238
	239	In this case, the BEGIN is freed immediately after execution since there
	240	are no active references to it: the anon sub prototype has
	241	C<CvWEAKOUTSIDE> set since it's not a closure, and $a points to the same
	242	CV, so it doesn't contribute to BEGIN's refcount either. When $a is
	243	executed, the C<eval '$x'> causes the chain of C<CvOUTSIDE>s to be followed,
	244	and the freed BEGIN is accessed.
	245
	246	To avoid this, whenever a CV and its associated pad is freed, any
	247	C<&> entries in the pad are explicitly removed from the pad, and if the
	248	refcount of the pointed-to anon sub is still positive, then that
	249	child's C<CvOUTSIDE> is set to point to its grandparent. This will only
	250	occur in the single specific case of a non-closure anon prototype
	251	having one or more active references (such as C<$a> above).
	252
	253	One other thing to consider is that a CV may be merely undefined
	254	rather than freed, eg C<undef &foo>. In this case, its refcount may
	255	not have reached zero, but we still delete its pad and its C<CvROOT> etc.
	256	Since various children may still have their C<CvOUTSIDE> pointing at this
	257	undefined CV, we keep its own C<CvOUTSIDE> for the time being, so that
	258	the chain of lexical scopes is unbroken. For example, the following
	259	should print 123:
	260
	261	my $x = 123;
	262	sub tmp { sub { eval '$x' } }
	263	my $a = tmp();
	264	undef &tmp;
	265	print $a->();
	266
	267	=cut
	268	*/
102d3b8a	269
d9088386 Z	270	typedef OP (Perl_call_checker)(pTHX_ OP , GV , SV *);
d9088386 Z	271
102d3b8a NC	272	/*
	273	* Local variables:
	274	* c-indentation-style: bsd
	275	* c-basic-offset: 4
14d04a33	276	* indent-tabs-mode: nil
102d3b8a NC	277	* End:
102d3b8a NC	278	*
14d04a33	279	* ex: set ts=8 sts=4 sw=4 et:
102d3b8a	280	*/