1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4  *    2000, 2001, 2002, 2003, 2004, by Larry Wall and others
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  *
9  * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
10  * and OP_SETSTATE that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15 
16 struct cop {
17     BASEOP
18     char *	cop_label;	/* label for this construct */
19 #ifdef USE_ITHREADS
20     char *	cop_stashpv;	/* package line was compiled in */
21     char *	cop_file;	/* file name the following line # is from */
22 #else
23     HV *	cop_stash;	/* package line was compiled in */
24     GV *	cop_filegv;	/* file the following line # is from */
25 #endif
26     U32		cop_seq;	/* parse sequence number */
27     I32		cop_arybase;	/* array base this line was compiled with */
28     line_t      cop_line;       /* line # of this command */
29     SV *	cop_warnings;	/* lexical warnings bitmask */
30     SV *	cop_io;		/* lexical IO defaults */
31 };
32 
33 #define Nullcop Null(COP*)
34 
35 #ifdef USE_ITHREADS
36 #  define CopFILE(c)		((c)->cop_file)
37 #  define CopFILEGV(c)		(CopFILE(c) \
38 				 ? gv_fetchfile(CopFILE(c)) : Nullgv)
39 
40 #  ifdef NETWARE
41 #    define CopFILE_set(c,pv)	((c)->cop_file = savepv(pv))
42 #  else
43 #    define CopFILE_set(c,pv)	((c)->cop_file = savesharedpv(pv))
44 #  endif
45 
46 #  define CopFILESV(c)		(CopFILE(c) \
47 				 ? GvSV(gv_fetchfile(CopFILE(c))) : Nullsv)
48 #  define CopFILEAV(c)		(CopFILE(c) \
49 				 ? GvAV(gv_fetchfile(CopFILE(c))) : Nullav)
50 #  define CopSTASHPV(c)		((c)->cop_stashpv)
51 
52 #  ifdef NETWARE
53 #    define CopSTASHPV_set(c,pv)	((c)->cop_stashpv = ((pv) ? savepv(pv) : Nullch))
54 #  else
55 #    define CopSTASHPV_set(c,pv)	((c)->cop_stashpv = savesharedpv(pv))
56 #  endif
57 
58 #  define CopSTASH(c)		(CopSTASHPV(c) \
59 				 ? gv_stashpv(CopSTASHPV(c),GV_ADD) : Nullhv)
60 #  define CopSTASH_set(c,hv)	CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : Nullch)
61 #  define CopSTASH_eq(c,hv)	((hv) && stashpv_hvname_match(c,hv))
62 #  ifdef NETWARE
63 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
64 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
65 #  else
66 #    define CopSTASH_free(c)	PerlMemShared_free(CopSTASHPV(c))
67 #    define CopFILE_free(c)	(PerlMemShared_free(CopFILE(c)),(CopFILE(c) = Nullch))
68 #  endif
69 #else
70 #  define CopFILEGV(c)		((c)->cop_filegv)
71 #  define CopFILEGV_set(c,gv)	((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
72 #  define CopFILE_set(c,pv)	CopFILEGV_set((c), gv_fetchfile(pv))
73 #  define CopFILESV(c)		(CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
74 #  define CopFILEAV(c)		(CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
75 #  define CopFILE(c)		(CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
76 #  define CopSTASH(c)		((c)->cop_stash)
77 #  define CopSTASH_set(c,hv)	((c)->cop_stash = (hv))
78 #  define CopSTASHPV(c)		(CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : Nullch)
79    /* cop_stash is not refcounted */
80 #  define CopSTASHPV_set(c,pv)	CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
81 #  define CopSTASH_eq(c,hv)	(CopSTASH(c) == (hv))
82 #  define CopSTASH_free(c)
83 #  define CopFILE_free(c)	(SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = Nullgv))
84 
85 #endif /* USE_ITHREADS */
86 
87 #define CopSTASH_ne(c,hv)	(!CopSTASH_eq(c,hv))
88 #define CopLINE(c)		((c)->cop_line)
89 #define CopLINE_inc(c)		(++CopLINE(c))
90 #define CopLINE_dec(c)		(--CopLINE(c))
91 #define CopLINE_set(c,l)	(CopLINE(c) = (l))
92 
93 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
94 #ifdef MACOS_TRADITIONAL
95 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
96 #else
97 #  define OutCopFILE(c) CopFILE(c)
98 #endif
99 
100 /*
101  * Here we have some enormously heavy (or at least ponderous) wizardry.
102  */
103 
104 /* subroutine context */
105 struct block_sub {
106     CV *	cv;
107     GV *	gv;
108     GV *	dfoutgv;
109 #ifndef USE_5005THREADS
110     AV *	savearray;
111 #endif /* USE_5005THREADS */
112     AV *	argarray;
113     long	olddepth;
114     U8		hasargs;
115     U8		lval;		/* XXX merge lval and hasargs? */
116     PAD		*oldcomppad;
117 };
118 
119 /* base for the next two macros. Don't use directly.
120  * Note that the refcnt of the cv is incremented twice;  The CX one is
121  * decremented by LEAVESUB, the other by LEAVE. */
122 
123 #define PUSHSUB_BASE(cx)						\
124 	cx->blk_sub.cv = cv;						\
125 	cx->blk_sub.olddepth = CvDEPTH(cv);				\
126 	cx->blk_sub.hasargs = hasargs;					\
127 	if (!CvDEPTH(cv)) {						\
128 	    (void)SvREFCNT_inc(cv);					\
129 	    (void)SvREFCNT_inc(cv);					\
130 	    SAVEFREESV(cv);						\
131 	}
132 
133 
134 #define PUSHSUB(cx)							\
135 	PUSHSUB_BASE(cx)						\
136 	cx->blk_sub.lval = PL_op->op_private &                          \
137 	                      (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
138 
139 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
140 #define PUSHSUB_DB(cx)							\
141 	PUSHSUB_BASE(cx)						\
142 	cx->blk_sub.lval = 0;
143 
144 
145 #define PUSHFORMAT(cx)							\
146 	cx->blk_sub.cv = cv;						\
147 	cx->blk_sub.gv = gv;						\
148 	cx->blk_sub.hasargs = 0;					\
149 	cx->blk_sub.dfoutgv = PL_defoutgv;				\
150 	(void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
151 
152 #ifdef USE_5005THREADS
153 #  define POP_SAVEARRAY() NOOP
154 #else
155 #  define POP_SAVEARRAY()						\
156     STMT_START {							\
157 	SvREFCNT_dec(GvAV(PL_defgv));					\
158 	GvAV(PL_defgv) = cx->blk_sub.savearray;				\
159     } STMT_END
160 #endif /* USE_5005THREADS */
161 
162 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
163  * leave any (a fast av_clear(ary), basically) */
164 #define CLEAR_ARGARRAY(ary) \
165     STMT_START {							\
166 	AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);			\
167 	SvPV_set(ary, (char*)AvALLOC(ary));				\
168 	AvFILLp(ary) = -1;						\
169     } STMT_END
170 
171 #define POPSUB(cx,sv)							\
172     STMT_START {							\
173 	if (cx->blk_sub.hasargs) {					\
174 	    POP_SAVEARRAY();						\
175 	    /* abandon @_ if it got reified */				\
176 	    if (AvREAL(cx->blk_sub.argarray)) {				\
177 		SSize_t fill = AvFILLp(cx->blk_sub.argarray);		\
178 		SvREFCNT_dec(cx->blk_sub.argarray);			\
179 		cx->blk_sub.argarray = newAV();				\
180 		av_extend(cx->blk_sub.argarray, fill);			\
181 		AvFLAGS(cx->blk_sub.argarray) = AVf_REIFY;		\
182 		CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;	\
183 	    }								\
184 	    else {							\
185 		CLEAR_ARGARRAY(cx->blk_sub.argarray);			\
186 	    }								\
187 	}								\
188 	sv = (SV*)cx->blk_sub.cv;					\
189 	if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))		\
190 	    sv = Nullsv;						\
191     } STMT_END
192 
193 #define LEAVESUB(sv)							\
194     STMT_START {							\
195 	if (sv)								\
196 	    SvREFCNT_dec(sv);						\
197     } STMT_END
198 
199 #define POPFORMAT(cx)							\
200 	setdefout(cx->blk_sub.dfoutgv);					\
201 	SvREFCNT_dec(cx->blk_sub.dfoutgv);
202 
203 /* eval context */
204 struct block_eval {
205     I32		old_in_eval;
206     I32		old_op_type;
207     SV *	old_namesv;
208     OP *	old_eval_root;
209     SV *	cur_text;
210     CV *	cv;
211 };
212 
213 #define PUSHEVAL(cx,n,fgv)						\
214     STMT_START {							\
215 	cx->blk_eval.old_in_eval = PL_in_eval;				\
216 	cx->blk_eval.old_op_type = PL_op->op_type;			\
217 	cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);		\
218 	cx->blk_eval.old_eval_root = PL_eval_root;			\
219 	cx->blk_eval.cur_text = PL_linestr;				\
220 	cx->blk_eval.cv = Nullcv; /* set by doeval(), as applicable */	\
221     } STMT_END
222 
223 #define POPEVAL(cx)							\
224     STMT_START {							\
225 	PL_in_eval = cx->blk_eval.old_in_eval;				\
226 	optype = cx->blk_eval.old_op_type;				\
227 	PL_eval_root = cx->blk_eval.old_eval_root;			\
228 	if (cx->blk_eval.old_namesv)					\
229 	    sv_2mortal(cx->blk_eval.old_namesv);			\
230     } STMT_END
231 
232 /* loop context */
233 struct block_loop {
234     char *	label;
235     I32		resetsp;
236     OP *	redo_op;
237     OP *	next_op;
238     OP *	last_op;
239 #ifdef USE_ITHREADS
240     void *	iterdata;
241     PAD		*oldcomppad;
242 #else
243     SV **	itervar;
244 #endif
245     SV *	itersave;
246     SV *	iterlval;
247     AV *	iterary;
248     IV		iterix;
249     IV		itermax;
250 };
251 
252 #ifdef USE_ITHREADS
253 #  define CxITERVAR(c)							\
254 	((c)->blk_loop.iterdata						\
255 	 ? (CxPADLOOP(cx) 						\
256 	    ? &CX_CURPAD_SV( (c)->blk_loop, 				\
257 		    INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))		\
258 	    : &GvSV((GV*)(c)->blk_loop.iterdata))			\
259 	 : (SV**)NULL)
260 #  define CX_ITERDATA_SET(cx,idata)					\
261 	CX_CURPAD_SAVE(cx->blk_loop);					\
262 	if ((cx->blk_loop.iterdata = (idata)))				\
263 	    cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));	\
264 	else								\
265 	    cx->blk_loop.itersave = Nullsv;
266 #else
267 #  define CxITERVAR(c)		((c)->blk_loop.itervar)
268 #  define CX_ITERDATA_SET(cx,ivar)					\
269 	if ((cx->blk_loop.itervar = (SV**)(ivar)))			\
270 	    cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));	\
271 	else								\
272 	    cx->blk_loop.itersave = Nullsv;
273 #endif
274 
275 #define PUSHLOOP(cx, dat, s)						\
276 	cx->blk_loop.label = PL_curcop->cop_label;			\
277 	cx->blk_loop.resetsp = s - PL_stack_base;			\
278 	cx->blk_loop.redo_op = cLOOP->op_redoop;			\
279 	cx->blk_loop.next_op = cLOOP->op_nextop;			\
280 	cx->blk_loop.last_op = cLOOP->op_lastop;			\
281 	cx->blk_loop.iterlval = Nullsv;					\
282 	cx->blk_loop.iterary = Nullav;					\
283 	cx->blk_loop.iterix = -1;					\
284 	CX_ITERDATA_SET(cx,dat);
285 
286 #define POPLOOP(cx)							\
287 	SvREFCNT_dec(cx->blk_loop.iterlval);				\
288 	if (CxITERVAR(cx)) {						\
289 	    SV **s_v_p = CxITERVAR(cx);					\
290 	    sv_2mortal(*s_v_p);						\
291 	    *s_v_p = cx->blk_loop.itersave;				\
292 	}								\
293 	if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
294 	    SvREFCNT_dec(cx->blk_loop.iterary);
295 
296 /* context common to subroutines, evals and loops */
297 struct block {
298     I32		blku_oldsp;	/* stack pointer to copy stuff down to */
299     COP *	blku_oldcop;	/* old curcop pointer */
300     I32		blku_oldretsp;	/* return stack index */
301     I32		blku_oldmarksp;	/* mark stack index */
302     I32		blku_oldscopesp;	/* scope stack index */
303     PMOP *	blku_oldpm;	/* values of pattern match vars */
304     U8		blku_gimme;	/* is this block running in list context? */
305 
306     union {
307 	struct block_sub	blku_sub;
308 	struct block_eval	blku_eval;
309 	struct block_loop	blku_loop;
310     } blk_u;
311 };
312 #define blk_oldsp	cx_u.cx_blk.blku_oldsp
313 #define blk_oldcop	cx_u.cx_blk.blku_oldcop
314 #define blk_oldretsp	cx_u.cx_blk.blku_oldretsp
315 #define blk_oldmarksp	cx_u.cx_blk.blku_oldmarksp
316 #define blk_oldscopesp	cx_u.cx_blk.blku_oldscopesp
317 #define blk_oldpm	cx_u.cx_blk.blku_oldpm
318 #define blk_gimme	cx_u.cx_blk.blku_gimme
319 #define blk_sub		cx_u.cx_blk.blk_u.blku_sub
320 #define blk_eval	cx_u.cx_blk.blk_u.blku_eval
321 #define blk_loop	cx_u.cx_blk.blk_u.blku_loop
322 
323 /* Enter a block. */
324 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],		\
325 	cx->cx_type		= t,					\
326 	cx->blk_oldsp		= sp - PL_stack_base,			\
327 	cx->blk_oldcop		= PL_curcop,				\
328 	cx->blk_oldmarksp	= PL_markstack_ptr - PL_markstack,	\
329 	cx->blk_oldscopesp	= PL_scopestack_ix,			\
330 	cx->blk_oldretsp	= PL_retstack_ix,			\
331 	cx->blk_oldpm		= PL_curpm,				\
332 	cx->blk_gimme		= (U8)gimme;				\
333 	DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n",	\
334 		    (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
335 
336 /* Exit a block (RETURN and LAST). */
337 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],			\
338 	newsp		 = PL_stack_base + cx->blk_oldsp,		\
339 	PL_curcop	 = cx->blk_oldcop,				\
340 	PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,		\
341 	PL_scopestack_ix = cx->blk_oldscopesp,				\
342 	PL_retstack_ix	 = cx->blk_oldretsp,				\
343 	pm		 = cx->blk_oldpm,				\
344 	gimme		 = cx->blk_gimme;				\
345 	DEBUG_SCOPE("POPBLOCK");					\
346 	DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",		\
347 		    (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
348 
349 /* Continue a block elsewhere (NEXT and REDO). */
350 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],			\
351 	PL_stack_sp	 = PL_stack_base + cx->blk_oldsp,		\
352 	PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,		\
353 	PL_scopestack_ix = cx->blk_oldscopesp,				\
354 	PL_retstack_ix	 = cx->blk_oldretsp,				\
355 	PL_curpm         = cx->blk_oldpm;				\
356 	DEBUG_SCOPE("TOPBLOCK");
357 
358 /* substitution context */
359 struct subst {
360     I32		sbu_iters;
361     I32		sbu_maxiters;
362     I32		sbu_rflags;
363     I32		sbu_oldsave;
364     bool	sbu_once;
365     bool	sbu_rxtainted;
366     char *	sbu_orig;
367     SV *	sbu_dstr;
368     SV *	sbu_targ;
369     char *	sbu_s;
370     char *	sbu_m;
371     char *	sbu_strend;
372     void *	sbu_rxres;
373     REGEXP *	sbu_rx;
374 };
375 #define sb_iters	cx_u.cx_subst.sbu_iters
376 #define sb_maxiters	cx_u.cx_subst.sbu_maxiters
377 #define sb_rflags	cx_u.cx_subst.sbu_rflags
378 #define sb_oldsave	cx_u.cx_subst.sbu_oldsave
379 #define sb_once		cx_u.cx_subst.sbu_once
380 #define sb_rxtainted	cx_u.cx_subst.sbu_rxtainted
381 #define sb_orig		cx_u.cx_subst.sbu_orig
382 #define sb_dstr		cx_u.cx_subst.sbu_dstr
383 #define sb_targ		cx_u.cx_subst.sbu_targ
384 #define sb_s		cx_u.cx_subst.sbu_s
385 #define sb_m		cx_u.cx_subst.sbu_m
386 #define sb_strend	cx_u.cx_subst.sbu_strend
387 #define sb_rxres	cx_u.cx_subst.sbu_rxres
388 #define sb_rx		cx_u.cx_subst.sbu_rx
389 
390 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],			\
391 	cx->sb_iters		= iters,				\
392 	cx->sb_maxiters		= maxiters,				\
393 	cx->sb_rflags		= r_flags,				\
394 	cx->sb_oldsave		= oldsave,				\
395 	cx->sb_once		= once,					\
396 	cx->sb_rxtainted	= rxtainted,				\
397 	cx->sb_orig		= orig,					\
398 	cx->sb_dstr		= dstr,					\
399 	cx->sb_targ		= targ,					\
400 	cx->sb_s		= s,					\
401 	cx->sb_m		= m,					\
402 	cx->sb_strend		= strend,				\
403 	cx->sb_rxres		= Null(void*),				\
404 	cx->sb_rx		= rx,					\
405 	cx->cx_type		= CXt_SUBST;				\
406 	rxres_save(&cx->sb_rxres, rx)
407 
408 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];			\
409 	rxres_free(&cx->sb_rxres)
410 
411 struct context {
412     U32		cx_type;	/* what kind of context this is */
413     union {
414 	struct block	cx_blk;
415 	struct subst	cx_subst;
416     } cx_u;
417 };
418 
419 #define CXTYPEMASK	0xff
420 #define CXt_NULL	0
421 #define CXt_SUB		1
422 #define CXt_EVAL	2
423 #define CXt_LOOP	3
424 #define CXt_SUBST	4
425 #define CXt_BLOCK	5
426 #define CXt_FORMAT	6
427 
428 /* private flags for CXt_EVAL */
429 #define CXp_REAL	0x00000100	/* truly eval'', not a lookalike */
430 #define CXp_TRYBLOCK	0x00000200	/* eval{}, not eval'' or similar */
431 
432 #ifdef USE_ITHREADS
433 /* private flags for CXt_LOOP */
434 #  define CXp_PADVAR	0x00000100	/* itervar lives on pad, iterdata
435 					   has pad offset; if not set,
436 					   iterdata holds GV* */
437 #  define CxPADLOOP(c)	(((c)->cx_type & (CXt_LOOP|CXp_PADVAR))		\
438 			 == (CXt_LOOP|CXp_PADVAR))
439 #endif
440 
441 #define CxTYPE(c)	((c)->cx_type & CXTYPEMASK)
442 #define CxREALEVAL(c)	(((c)->cx_type & (CXt_EVAL|CXp_REAL))		\
443 			 == (CXt_EVAL|CXp_REAL))
444 #define CxTRYBLOCK(c)	(((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))	\
445 			 == (CXt_EVAL|CXp_TRYBLOCK))
446 
447 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
448 
449 /*
450 =head1 "Gimme" Values
451 */
452 
453 /*
454 =for apidoc AmU||G_SCALAR
455 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
456 L<perlcall>.
457 
458 =for apidoc AmU||G_ARRAY
459 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
460 L<perlcall>.
461 
462 =for apidoc AmU||G_VOID
463 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
464 
465 =for apidoc AmU||G_DISCARD
466 Indicates that arguments returned from a callback should be discarded.  See
467 L<perlcall>.
468 
469 =for apidoc AmU||G_EVAL
470 
471 Used to force a Perl C<eval> wrapper around a callback.  See
472 L<perlcall>.
473 
474 =for apidoc AmU||G_NOARGS
475 
476 Indicates that no arguments are being sent to a callback.  See
477 L<perlcall>.
478 
479 =cut
480 */
481 
482 #define G_SCALAR	0
483 #define G_ARRAY		1
484 #define G_VOID		128	/* skip this bit when adding flags below */
485 
486 /* extra flags for Perl_call_* routines */
487 #define G_DISCARD	2	/* Call FREETMPS. */
488 #define G_EVAL		4	/* Assume eval {} around subroutine call. */
489 #define G_NOARGS	8	/* Don't construct a @_ array. */
490 #define G_KEEPERR      16	/* Append errors to $@, don't overwrite it */
491 #define G_NODEBUG      32	/* Disable debugging at toplevel.  */
492 #define G_METHOD       64       /* Calling method. */
493 
494 /* flag bits for PL_in_eval */
495 #define EVAL_NULL	0	/* not in an eval */
496 #define EVAL_INEVAL	1	/* some enclosing scope is an eval */
497 #define EVAL_WARNONLY	2	/* used by yywarn() when calling yyerror() */
498 #define EVAL_KEEPERR	4	/* set by Perl_call_sv if G_KEEPERR */
499 #define EVAL_INREQUIRE	8	/* The code is being required. */
500 
501 /* Support for switching (stack and block) contexts.
502  * This ensures magic doesn't invalidate local stack and cx pointers.
503  */
504 
505 #define PERLSI_UNKNOWN		-1
506 #define PERLSI_UNDEF		0
507 #define PERLSI_MAIN		1
508 #define PERLSI_MAGIC		2
509 #define PERLSI_SORT		3
510 #define PERLSI_SIGNAL		4
511 #define PERLSI_OVERLOAD		5
512 #define PERLSI_DESTROY		6
513 #define PERLSI_WARNHOOK		7
514 #define PERLSI_DIEHOOK		8
515 #define PERLSI_REQUIRE		9
516 
517 struct stackinfo {
518     AV *		si_stack;	/* stack for current runlevel */
519     PERL_CONTEXT *	si_cxstack;	/* context stack for runlevel */
520     I32			si_cxix;	/* current context index */
521     I32			si_cxmax;	/* maximum allocated index */
522     I32			si_type;	/* type of runlevel */
523     struct stackinfo *	si_prev;
524     struct stackinfo *	si_next;
525     I32			si_markoff;	/* offset where markstack begins for us.
526 					 * currently used only with DEBUGGING,
527 					 * but not #ifdef-ed for bincompat */
528 };
529 
530 typedef struct stackinfo PERL_SI;
531 
532 #define cxstack		(PL_curstackinfo->si_cxstack)
533 #define cxstack_ix	(PL_curstackinfo->si_cxix)
534 #define cxstack_max	(PL_curstackinfo->si_cxmax)
535 
536 #ifdef DEBUGGING
537 #  define	SET_MARK_OFFSET \
538     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
539 #else
540 #  define	SET_MARK_OFFSET NOOP
541 #endif
542 
543 #define PUSHSTACKi(type) \
544     STMT_START {							\
545 	PERL_SI *next = PL_curstackinfo->si_next;			\
546 	if (!next) {							\
547 	    next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);	\
548 	    next->si_prev = PL_curstackinfo;				\
549 	    PL_curstackinfo->si_next = next;				\
550 	}								\
551 	next->si_type = type;						\
552 	next->si_cxix = -1;						\
553 	AvFILLp(next->si_stack) = 0;					\
554 	SWITCHSTACK(PL_curstack,next->si_stack);			\
555 	PL_curstackinfo = next;						\
556 	SET_MARK_OFFSET;						\
557     } STMT_END
558 
559 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
560 
561 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
562  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
563 #define POPSTACK \
564     STMT_START {							\
565 	dSP;								\
566 	PERL_SI *prev = PL_curstackinfo->si_prev;			\
567 	if (!prev) {							\
568 	    PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");		\
569 	    my_exit(1);							\
570 	}								\
571 	SWITCHSTACK(PL_curstack,prev->si_stack);			\
572 	/* don't free prev here, free them all at the END{} */		\
573 	PL_curstackinfo = prev;						\
574     } STMT_END
575 
576 #define POPSTACK_TO(s) \
577     STMT_START {							\
578 	while (PL_curstack != s) {					\
579 	    dounwind(-1);						\
580 	    POPSTACK;							\
581 	}								\
582     } STMT_END
583 
584 #define IN_PERL_COMPILETIME	(PL_curcop == &PL_compiling)
585 #define IN_PERL_RUNTIME		(PL_curcop != &PL_compiling)
586 
587