Stop delete local $ENV{foo} from leaking

[perl5.git] / scope.h

/*    scope.h
 *
 *    Copyright (C) 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001,
 *    2002, 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.
 *
 */

/* *** these are ordered by number of of auto-popped args */

/* zero args */

#define SAVEt_ALLOC		0
#define SAVEt_CLEARPADRANGE	1
#define SAVEt_CLEARSV		2
#define SAVEt_REGCONTEXT	3
/*** SPARE      	        4 ***/

#define SAVEt_ARG0_MAX		4

/* one arg */

#define SAVEt_BOOL		5
#define SAVEt_COMPILE_WARNINGS	6
#define SAVEt_COMPPAD		7
#define SAVEt_FREECOPHH		8
#define SAVEt_FREEOP		9
#define SAVEt_FREEPV		10
#define SAVEt_FREESV		11
#define SAVEt_I16		12
#define SAVEt_I32_SMALL		13
#define SAVEt_I8		14
#define SAVEt_INT_SMALL		15
#define SAVEt_MORTALIZESV	16
#define SAVEt_NSTAB		17
#define SAVEt_OP		18
#define SAVEt_PARSER		19
#define SAVEt_STACK_POS		20

#define SAVEt_ARG1_MAX		20

/* two args */

#define SAVEt_ADELETE		21
#define SAVEt_APTR		22
#define SAVEt_AV		23
#define SAVEt_DESTRUCTOR	24
#define SAVEt_DESTRUCTOR_X	25
#define SAVEt_GENERIC_PVREF	26
#define SAVEt_GENERIC_SVREF	27
#define SAVEt_GP		28
#define SAVEt_GVSV		29
#define SAVEt_HINTS		30
#define SAVEt_HPTR		31
#define SAVEt_HV		32
#define SAVEt_I32		33
#define SAVEt_INT		34
#define SAVEt_ITEM		35
#define SAVEt_IV		36
#define SAVEt_LONG		37
#define SAVEt_PPTR		38
#define SAVEt_SAVESWITCHSTACK	39
#define SAVEt_SHARED_PVREF	40
#define SAVEt_SPTR		41
#define SAVEt_STACK_CXPOS	42
#define SAVEt_SV		43
#define SAVEt_SVREF		44
#define SAVEt_VPTR		45

#define SAVEt_ARG2_MAX		45

/* three args */

#define SAVEt_AELEM		46
#define SAVEt_DELETE		47
#define SAVEt_HELEM		48
#define SAVEt_PADSV_AND_MORTALIZE 49
#define SAVEt_SET_SVFLAGS	50
#define SAVEt_GVSLOT		51

#define SAVEf_SETMAGIC		1
#define SAVEf_KEEPOLDELEM	2

#define SAVE_TIGHT_SHIFT	6
#define SAVE_MASK		0x3F

#define save_aelem(av,idx,sptr)	save_aelem_flags(av,idx,sptr,SAVEf_SETMAGIC)
#define save_helem(hv,key,sptr)	save_helem_flags(hv,key,sptr,SAVEf_SETMAGIC)

#ifndef SCOPE_SAVES_SIGNAL_MASK
#define SCOPE_SAVES_SIGNAL_MASK 0
#endif

/* the maximum number of entries that might be pushed using the SS_ADD*
 * macros */
#define SS_MAXPUSH 4

#define SSCHECK(need) if (PL_savestack_ix + (I32)(need) + SS_MAXPUSH > PL_savestack_max) savestack_grow()
#define SSGROW(need) if (PL_savestack_ix + (I32)(need) + SS_MAXPUSH > PL_savestack_max) savestack_grow_cnt(need + SS_MAXPUSH)
#define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
#define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
#define SSPUSHBOOL(p) (PL_savestack[PL_savestack_ix++].any_bool = (p))
#define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
#define SSPUSHUV(u) (PL_savestack[PL_savestack_ix++].any_uv = (UV)(u))
#define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
#define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
#define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))

/* SS_ADD*: newer, faster versions of the above. Don't mix the two sets of
 * macros. These are fast because they save reduce accesses to the PL_
 * vars and move the size check to the end. Doing the check last means
 * that values in registers will have been pushed and no longer needed, so
 * don't need saving around the call to grow. Also, tail-call elimination
 * of the grow() can be done. These changes reduce the code of something
 * like save_pushptrptr() to half its former size.
 * Of course, doing the size check *after* pushing means we must always
 * ensure there are SS_MAXPUSH free slots on the savestack
 *
 * These are for internal core use only and are subject to change */

#define dSS_ADD \
    I32 ix = PL_savestack_ix;     \
    ANY *ssp = &PL_savestack[ix];

#define SS_ADD_END(need) \
    assert((need) <= SS_MAXPUSH);                               \
    ix += (need);                                               \
    PL_savestack_ix = ix;                                       \
    assert(ix <= PL_savestack_max);                             \
    if ((ix + SS_MAXPUSH) > PL_savestack_max) savestack_grow(); \
    assert(PL_savestack_ix + SS_MAXPUSH <= PL_savestack_max);

#define SS_ADD_INT(i)   ((ssp++)->any_i32 = (I32)(i))
#define SS_ADD_LONG(i)  ((ssp++)->any_long = (long)(i))
#define SS_ADD_BOOL(p)  ((ssp++)->any_bool = (p))
#define SS_ADD_IV(i)    ((ssp++)->any_iv = (IV)(i))
#define SS_ADD_UV(u)    ((ssp++)->any_uv = (UV)(u))
#define SS_ADD_PTR(p)   ((ssp++)->any_ptr = (void*)(p))
#define SS_ADD_DPTR(p)  ((ssp++)->any_dptr = (p))
#define SS_ADD_DXPTR(p) ((ssp++)->any_dxptr = (p))

#define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
#define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
#define SSPOPBOOL (PL_savestack[--PL_savestack_ix].any_bool)
#define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
#define SSPOPUV (PL_savestack[--PL_savestack_ix].any_uv)
#define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
#define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
#define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)


/*
=head1 Callback Functions

=for apidoc Ams||SAVETMPS
Opening bracket for temporaries on a callback.  See C<FREETMPS> and
L<perlcall>.

=for apidoc Ams||FREETMPS
Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
L<perlcall>.

=for apidoc Ams||ENTER
Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.

=for apidoc Ams||LEAVE
Closing bracket on a callback.  See C<ENTER> and L<perlcall>.

=over

=item ENTER_with_name(name)

Same as C<ENTER>, but when debugging is enabled it also associates the
given literal string with the new scope.

=item LEAVE_with_name(name)

Same as C<LEAVE>, but when debugging is enabled it first checks that the
scope has the given name. Name must be a literal string.

=back

=cut
*/

#define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
#define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()

#ifdef DEBUGGING
#define ENTER							\
    STMT_START {						\
	push_scope();						\
	DEBUG_SCOPE("ENTER")					\
    } STMT_END
#define LEAVE							\
    STMT_START {						\
	DEBUG_SCOPE("LEAVE")					\
	pop_scope();						\
    } STMT_END
#define ENTER_with_name(name)						\
    STMT_START {							\
	push_scope();							\
	if (PL_scopestack_name)						\
	    PL_scopestack_name[PL_scopestack_ix-1] = name;		\
	DEBUG_SCOPE("ENTER \"" name "\"")				\
    } STMT_END
#define LEAVE_with_name(name)						\
    STMT_START {							\
	DEBUG_SCOPE("LEAVE \"" name "\"")				\
	if (PL_scopestack_name)	{					\
	    assert(((char*)PL_scopestack_name[PL_scopestack_ix-1]	\
			== (char*)name)					\
		    || strEQ(PL_scopestack_name[PL_scopestack_ix-1], name));        \
	}								\
	pop_scope();							\
    } STMT_END
#else
#define ENTER push_scope()
#define LEAVE pop_scope()
#define ENTER_with_name(name) ENTER
#define LEAVE_with_name(name) LEAVE
#endif
#define LEAVE_SCOPE(old) STMT_START { \
	if (PL_savestack_ix > old) leave_scope(old); \
    } STMT_END

#define SAVEI8(i)	save_I8((I8*)&(i))
#define SAVEI16(i)	save_I16((I16*)&(i))
#define SAVEI32(i)	save_I32((I32*)&(i))
#define SAVEINT(i)	save_int((int*)&(i))
#define SAVEIV(i)	save_iv((IV*)&(i))
#define SAVELONG(l)	save_long((long*)&(l))
#define SAVEBOOL(b)	save_bool(&(b))
#define SAVESPTR(s)	save_sptr((SV**)&(s))
#define SAVEPPTR(s)	save_pptr((char**)&(s))
#define SAVEVPTR(s)	save_vptr((void*)&(s))
#define SAVEPADSVANDMORTALIZE(s)	save_padsv_and_mortalize(s)
#define SAVEFREESV(s)	save_freesv(MUTABLE_SV(s))
#define SAVEMORTALIZESV(s)	save_mortalizesv(MUTABLE_SV(s))
#define SAVEFREEOP(o)	save_freeop((OP*)(o))
#define SAVEFREEPV(p)	save_freepv((char*)(p))
#define SAVECLEARSV(sv)	save_clearsv((SV**)&(sv))
#define SAVEGENERICSV(s)	save_generic_svref((SV**)&(s))
#define SAVEGENERICPV(s)	save_generic_pvref((char**)&(s))
#define SAVESHAREDPV(s)		save_shared_pvref((char**)&(s))
#define SAVESETSVFLAGS(sv,mask,val)	save_set_svflags(sv,mask,val)
#define SAVEFREECOPHH(h)	save_pushptr((void *)(h), SAVEt_FREECOPHH)
#define SAVEDELETE(h,k,l) \
	  save_delete(MUTABLE_HV(h), (char*)(k), (I32)(l))
#define SAVEHDELETE(h,s) \
	  save_hdelete(MUTABLE_HV(h), (s))
#define SAVEADELETE(a,k) \
	  save_adelete(MUTABLE_AV(a), (I32)(k))
#define SAVEDESTRUCTOR(f,p) \
	  save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), (void*)(p))

#define SAVEDESTRUCTOR_X(f,p) \
	  save_destructor_x((DESTRUCTORFUNC_t)(f), (void*)(p))

#define SAVESTACK_POS() \
    STMT_START {				   \
        dSS_ADD;                                   \
        SS_ADD_INT(PL_stack_sp - PL_stack_base);   \
        SS_ADD_UV(SAVEt_STACK_POS);                \
        SS_ADD_END(2);                             \
    } STMT_END

#define SAVEOP()	save_op()

#define SAVEHINTS()	save_hints()

#define SAVECOMPPAD() save_pushptr(MUTABLE_SV(PL_comppad), SAVEt_COMPPAD)

#define SAVESWITCHSTACK(f,t) \
    STMT_START {					\
	save_pushptrptr(MUTABLE_SV(f), MUTABLE_SV(t), SAVEt_SAVESWITCHSTACK); \
	SWITCHSTACK((f),(t));				\
	PL_curstackinfo->si_stack = (t);		\
    } STMT_END

/* Need to do the cop warnings like this, rather than a "SAVEFREESHAREDPV",
   because realloc() means that the value can actually change. Possibly
   could have done savefreesharedpvREF, but this way actually seems cleaner,
   as it simplifies the code that does the saves, and reduces the load on the
   save stack.  */
#define SAVECOMPILEWARNINGS() save_pushptr(PL_compiling.cop_warnings, SAVEt_COMPILE_WARNINGS)

#define SAVESTACK_CXPOS() \
    STMT_START {                                   \
        dSS_ADD;                                   \
        SS_ADD_INT(cxstack[cxstack_ix].blk_oldsp); \
        SS_ADD_INT(cxstack_ix);                    \
        SS_ADD_UV(SAVEt_STACK_CXPOS);              \
        SS_ADD_END(3);                             \
    } STMT_END

#define SAVEPARSER(p) save_pushptr((p), SAVEt_PARSER)

#ifdef USE_ITHREADS
#  define SAVECOPSTASH_FREE(c)	SAVEIV((c)->cop_stashoff)
#  define SAVECOPFILE(c)	SAVEPPTR(CopFILE(c))
#  define SAVECOPFILE_FREE(c)	SAVESHAREDPV(CopFILE(c))
#else
#  /* XXX not refcounted */
#  define SAVECOPSTASH_FREE(c)	SAVESPTR(CopSTASH(c))
#  define SAVECOPFILE(c)	SAVESPTR(CopFILEGV(c))
#  define SAVECOPFILE_FREE(c)	SAVEGENERICSV(CopFILEGV(c))
#endif

#define SAVECOPLINE(c)		SAVEI32(CopLINE(c))

/* SSNEW() temporarily allocates a specified number of bytes of data on the
 * savestack.  It returns an integer index into the savestack, because a
 * pointer would get broken if the savestack is moved on reallocation.
 * SSNEWa() works like SSNEW(), but also aligns the data to the specified
 * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
 * alignment will be preserved through savestack reallocation *only* if
 * realloc returns data aligned to a size divisible by "align"!
 *
 * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
 */

#define SSNEW(size)             Perl_save_alloc(aTHX_ (size), 0)
#define SSNEWt(n,t)             SSNEW((n)*sizeof(t))
#define SSNEWa(size,align)	Perl_save_alloc(aTHX_ (size), \
    (I32)(align - ((size_t)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
#define SSNEWat(n,t,align)	SSNEWa((n)*sizeof(t), align)

#define SSPTR(off,type)         ((type)  ((char*)PL_savestack + off))
#define SSPTRt(off,type)        ((type*) ((char*)PL_savestack + off))

#define save_freesv(op)		save_pushptr((void *)(op), SAVEt_FREESV)
#define save_mortalizesv(op)	save_pushptr((void *)(op), SAVEt_MORTALIZESV)

# define save_freeop(op)                    \
STMT_START {                                 \
      OP * const _o = (OP *)(op);             \
      assert(!_o->op_savefree);               \
      _o->op_savefree = 1;                     \
      save_pushptr((void *)(_o), SAVEt_FREEOP); \
    } STMT_END
#define save_freepv(pv)		save_pushptr((void *)(pv), SAVEt_FREEPV)
#define save_op()		save_pushptr((void *)(PL_op), SAVEt_OP)

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set ts=8 sts=4 sw=4 et:
 */