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[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (c) 1991-2002, Larry Wall
4  *
5  *    You may distribute under the terms of either the GNU General Public
6  *    License or the Artistic License, as specified in the README file.
7  *
8  */
9
10 struct cop {
11     BASEOP
12     char *      cop_label;      /* label for this construct */
13 #ifdef USE_ITHREADS
14     char *      cop_stashpv;    /* package line was compiled in */
15     char *      cop_file;       /* file name the following line # is from */
16 #else
17     HV *        cop_stash;      /* package line was compiled in */
18     GV *        cop_filegv;     /* file the following line # is from */
19 #endif
20     U32         cop_seq;        /* parse sequence number */
21     I32         cop_arybase;    /* array base this line was compiled with */
22     line_t      cop_line;       /* line # of this command */
23     SV *        cop_warnings;   /* lexical warnings bitmask */
24     SV *        cop_io;         /* lexical IO defaults */
25 };
26
27 #define Nullcop Null(COP*)
28
29 #ifdef USE_ITHREADS
30 #  define CopFILE(c)            ((c)->cop_file)
31 #  define CopFILEGV(c)          (CopFILE(c) \
32                                  ? gv_fetchfile(CopFILE(c)) : Nullgv)
33 #  define CopFILE_set(c,pv)     ((c)->cop_file = savesharedpv(pv))
34 #  define CopFILESV(c)          (CopFILE(c) \
35                                  ? GvSV(gv_fetchfile(CopFILE(c))) : Nullsv)
36 #  define CopFILEAV(c)          (CopFILE(c) \
37                                  ? GvAV(gv_fetchfile(CopFILE(c))) : Nullav)
38 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
39 #  define CopSTASHPV_set(c,pv)  ((c)->cop_stashpv = savesharedpv(pv))
40 #  define CopSTASH(c)           (CopSTASHPV(c) \
41                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : Nullhv)
42 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME(hv) : Nullch)
43 #  define CopSTASH_eq(c,hv)     ((hv)                                   \
44                                  && (CopSTASHPV(c) == HvNAME(hv)        \
45                                      || (CopSTASHPV(c) && HvNAME(hv)    \
46                                          && strEQ(CopSTASHPV(c), HvNAME(hv)))))
47 #  define CopSTASH_free(c)      PerlMemShared_free(CopSTASHPV(c))      
48 #  define CopFILE_free(c)       (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = Nullch))      
49 #else
50 #  define CopFILEGV(c)          ((c)->cop_filegv)
51 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
52 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
53 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
54 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
55 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
56 #  define CopSTASH(c)           ((c)->cop_stash)
57 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
58 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME(CopSTASH(c)) : Nullch)
59    /* cop_stash is not refcounted */
60 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
61 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
62 #  define CopSTASH_free(c)      
63 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = Nullgv))
64
65 #endif /* USE_ITHREADS */
66
67 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
68 #define CopLINE(c)              ((c)->cop_line)
69 #define CopLINE_inc(c)          (++CopLINE(c))
70 #define CopLINE_dec(c)          (--CopLINE(c))
71 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
72
73 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
74 #ifdef MACOS_TRADITIONAL
75 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
76 #else
77 #  define OutCopFILE(c) CopFILE(c)
78 #endif
79
80 /*
81  * Here we have some enormously heavy (or at least ponderous) wizardry.
82  */
83
84 /* subroutine context */
85 struct block_sub {
86     CV *        cv;
87     GV *        gv;
88     GV *        dfoutgv;
89 #ifndef USE_5005THREADS
90     AV *        savearray;
91 #endif /* USE_5005THREADS */
92     AV *        argarray;
93     U16         olddepth;
94     U8          hasargs;
95     U8          lval;           /* XXX merge lval and hasargs? */
96     SV **       oldcurpad;
97 };
98
99 #define PUSHSUB(cx)                                                     \
100         cx->blk_sub.cv = cv;                                            \
101         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
102         cx->blk_sub.hasargs = hasargs;                                  \
103         cx->blk_sub.lval = PL_op->op_private &                          \
104                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
105
106 #define PUSHFORMAT(cx)                                                  \
107         cx->blk_sub.cv = cv;                                            \
108         cx->blk_sub.gv = gv;                                            \
109         cx->blk_sub.hasargs = 0;                                        \
110         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
111         (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
112
113 #ifdef USE_5005THREADS
114 #  define POP_SAVEARRAY() NOOP
115 #else
116 #  define POP_SAVEARRAY()                                               \
117     STMT_START {                                                        \
118         SvREFCNT_dec(GvAV(PL_defgv));                                   \
119         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
120     } STMT_END
121 #endif /* USE_5005THREADS */
122
123 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
124  * leave any (a fast av_clear(ary), basically) */
125 #define CLEAR_ARGARRAY(ary) \
126     STMT_START {                                                        \
127         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
128         SvPVX(ary) = (char*)AvALLOC(ary);                               \
129         AvFILLp(ary) = -1;                                              \
130     } STMT_END
131
132 #define POPSUB(cx,sv)                                                   \
133     STMT_START {                                                        \
134         if (cx->blk_sub.hasargs) {                                      \
135             POP_SAVEARRAY();                                            \
136             /* abandon @_ if it got reified */                          \
137             if (AvREAL(cx->blk_sub.argarray)) {                         \
138                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
139                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
140                 cx->blk_sub.argarray = newAV();                         \
141                 av_extend(cx->blk_sub.argarray, fill);                  \
142                 AvFLAGS(cx->blk_sub.argarray) = AVf_REIFY;              \
143                 cx->blk_sub.oldcurpad[0] = (SV*)cx->blk_sub.argarray;   \
144             }                                                           \
145             else {                                                      \
146                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
147             }                                                           \
148         }                                                               \
149         sv = (SV*)cx->blk_sub.cv;                                       \
150         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
151             sv = Nullsv;                                                \
152     } STMT_END
153
154 #define LEAVESUB(sv)                                                    \
155     STMT_START {                                                        \
156         if (sv)                                                         \
157             SvREFCNT_dec(sv);                                           \
158     } STMT_END
159
160 #define POPFORMAT(cx)                                                   \
161         setdefout(cx->blk_sub.dfoutgv);                                 \
162         SvREFCNT_dec(cx->blk_sub.dfoutgv);
163
164 /* eval context */
165 struct block_eval {
166     I32         old_in_eval;
167     I32         old_op_type;
168     SV *        old_namesv;
169     OP *        old_eval_root;
170     SV *        cur_text;
171     CV *        cv;
172 };
173
174 #define PUSHEVAL(cx,n,fgv)                                              \
175     STMT_START {                                                        \
176         cx->blk_eval.old_in_eval = PL_in_eval;                          \
177         cx->blk_eval.old_op_type = PL_op->op_type;                      \
178         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);          \
179         cx->blk_eval.old_eval_root = PL_eval_root;                      \
180         cx->blk_eval.cur_text = PL_linestr;                             \
181         cx->blk_eval.cv = Nullcv; /* set by doeval(), as applicable */  \
182     } STMT_END
183
184 #define POPEVAL(cx)                                                     \
185     STMT_START {                                                        \
186         PL_in_eval = cx->blk_eval.old_in_eval;                          \
187         optype = cx->blk_eval.old_op_type;                              \
188         PL_eval_root = cx->blk_eval.old_eval_root;                      \
189         if (cx->blk_eval.old_namesv)                                    \
190             sv_2mortal(cx->blk_eval.old_namesv);                        \
191     } STMT_END
192
193 /* loop context */
194 struct block_loop {
195     char *      label;
196     I32         resetsp;
197     OP *        redo_op;
198     OP *        next_op;
199     OP *        last_op;
200 #ifdef USE_ITHREADS
201     void *      iterdata;
202     SV **       oldcurpad;
203 #else
204     SV **       itervar;
205 #endif
206     SV *        itersave;
207     SV *        iterlval;
208     AV *        iterary;
209     IV          iterix;
210     IV          itermax;
211 };
212
213 #ifdef USE_ITHREADS
214 #  define CxITERVAR(c)                                                  \
215         ((c)->blk_loop.iterdata                                         \
216          ? (CxPADLOOP(cx)                                               \
217             ? &((c)->blk_loop.oldcurpad)[INT2PTR(PADOFFSET, (c)->blk_loop.iterdata)] \
218             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
219          : (SV**)NULL)
220 #  define CX_ITERDATA_SET(cx,idata)                                     \
221         cx->blk_loop.oldcurpad = PL_curpad;                             \
222         if ((cx->blk_loop.iterdata = (idata)))                          \
223             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
224 #else
225 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
226 #  define CX_ITERDATA_SET(cx,ivar)                                      \
227         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
228             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
229 #endif
230
231 #define PUSHLOOP(cx, dat, s)                                            \
232         cx->blk_loop.label = PL_curcop->cop_label;                      \
233         cx->blk_loop.resetsp = s - PL_stack_base;                       \
234         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
235         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
236         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
237         cx->blk_loop.iterlval = Nullsv;                                 \
238         cx->blk_loop.iterary = Nullav;                                  \
239         cx->blk_loop.iterix = -1;                                       \
240         CX_ITERDATA_SET(cx,dat);
241
242 #define POPLOOP(cx)                                                     \
243         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
244         if (CxITERVAR(cx)) {                                            \
245             SV **s_v_p = CxITERVAR(cx);                                 \
246             sv_2mortal(*s_v_p);                                         \
247             *s_v_p = cx->blk_loop.itersave;                             \
248         }                                                               \
249         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
250             SvREFCNT_dec(cx->blk_loop.iterary);
251
252 /* context common to subroutines, evals and loops */
253 struct block {
254     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
255     COP *       blku_oldcop;    /* old curcop pointer */
256     I32         blku_oldretsp;  /* return stack index */
257     I32         blku_oldmarksp; /* mark stack index */
258     I32         blku_oldscopesp;        /* scope stack index */
259     PMOP *      blku_oldpm;     /* values of pattern match vars */
260     U8          blku_gimme;     /* is this block running in list context? */
261
262     union {
263         struct block_sub        blku_sub;
264         struct block_eval       blku_eval;
265         struct block_loop       blku_loop;
266     } blk_u;
267 };
268 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
269 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
270 #define blk_oldretsp    cx_u.cx_blk.blku_oldretsp
271 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
272 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
273 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
274 #define blk_gimme       cx_u.cx_blk.blku_gimme
275 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
276 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
277 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
278
279 /* Enter a block. */
280 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
281         cx->cx_type             = t,                                    \
282         cx->blk_oldsp           = sp - PL_stack_base,                   \
283         cx->blk_oldcop          = PL_curcop,                            \
284         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
285         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
286         cx->blk_oldretsp        = PL_retstack_ix,                       \
287         cx->blk_oldpm           = PL_curpm,                             \
288         cx->blk_gimme           = gimme;                                \
289         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
290                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
291
292 /* Exit a block (RETURN and LAST). */
293 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
294         newsp            = PL_stack_base + cx->blk_oldsp,               \
295         PL_curcop        = cx->blk_oldcop,                              \
296         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
297         PL_scopestack_ix = cx->blk_oldscopesp,                          \
298         PL_retstack_ix   = cx->blk_oldretsp,                            \
299         pm               = cx->blk_oldpm,                               \
300         gimme            = cx->blk_gimme;                               \
301         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
302                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
303
304 /* Continue a block elsewhere (NEXT and REDO). */
305 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
306         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
307         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
308         PL_scopestack_ix = cx->blk_oldscopesp,                          \
309         PL_retstack_ix   = cx->blk_oldretsp,                            \
310         PL_curpm         = cx->blk_oldpm
311
312 /* substitution context */
313 struct subst {
314     I32         sbu_iters;
315     I32         sbu_maxiters;
316     I32         sbu_rflags;
317     I32         sbu_oldsave;
318     bool        sbu_once;
319     bool        sbu_rxtainted;
320     char *      sbu_orig;
321     SV *        sbu_dstr;
322     SV *        sbu_targ;
323     char *      sbu_s;
324     char *      sbu_m;
325     char *      sbu_strend;
326     void *      sbu_rxres;
327     REGEXP *    sbu_rx;
328 };
329 #define sb_iters        cx_u.cx_subst.sbu_iters
330 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
331 #define sb_rflags       cx_u.cx_subst.sbu_rflags
332 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
333 #define sb_once         cx_u.cx_subst.sbu_once
334 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
335 #define sb_orig         cx_u.cx_subst.sbu_orig
336 #define sb_dstr         cx_u.cx_subst.sbu_dstr
337 #define sb_targ         cx_u.cx_subst.sbu_targ
338 #define sb_s            cx_u.cx_subst.sbu_s
339 #define sb_m            cx_u.cx_subst.sbu_m
340 #define sb_strend       cx_u.cx_subst.sbu_strend
341 #define sb_rxres        cx_u.cx_subst.sbu_rxres
342 #define sb_rx           cx_u.cx_subst.sbu_rx
343
344 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
345         cx->sb_iters            = iters,                                \
346         cx->sb_maxiters         = maxiters,                             \
347         cx->sb_rflags           = r_flags,                              \
348         cx->sb_oldsave          = oldsave,                              \
349         cx->sb_once             = once,                                 \
350         cx->sb_rxtainted        = rxtainted,                            \
351         cx->sb_orig             = orig,                                 \
352         cx->sb_dstr             = dstr,                                 \
353         cx->sb_targ             = targ,                                 \
354         cx->sb_s                = s,                                    \
355         cx->sb_m                = m,                                    \
356         cx->sb_strend           = strend,                               \
357         cx->sb_rxres            = Null(void*),                          \
358         cx->sb_rx               = rx,                                   \
359         cx->cx_type             = CXt_SUBST;                            \
360         rxres_save(&cx->sb_rxres, rx)
361
362 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
363         rxres_free(&cx->sb_rxres)
364
365 struct context {
366     U32         cx_type;        /* what kind of context this is */
367     union {
368         struct block    cx_blk;
369         struct subst    cx_subst;
370     } cx_u;
371 };
372
373 #define CXTYPEMASK      0xff
374 #define CXt_NULL        0
375 #define CXt_SUB         1
376 #define CXt_EVAL        2
377 #define CXt_LOOP        3
378 #define CXt_SUBST       4
379 #define CXt_BLOCK       5
380 #define CXt_FORMAT      6
381
382 /* private flags for CXt_EVAL */
383 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
384 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
385
386 #ifdef USE_ITHREADS
387 /* private flags for CXt_LOOP */
388 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
389                                            has pad offset; if not set,
390                                            iterdata holds GV* */
391 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
392                          == (CXt_LOOP|CXp_PADVAR))
393 #endif
394
395 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
396 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
397                          == (CXt_EVAL|CXp_REAL))
398 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
399                          == (CXt_EVAL|CXp_TRYBLOCK))
400
401 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
402
403 /* 
404 =head1 "Gimme" Values
405 */
406
407 /*
408 =for apidoc AmU||G_SCALAR
409 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
410 L<perlcall>.
411
412 =for apidoc AmU||G_ARRAY
413 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
414 L<perlcall>.
415
416 =for apidoc AmU||G_VOID
417 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
418
419 =for apidoc AmU||G_DISCARD
420 Indicates that arguments returned from a callback should be discarded.  See
421 L<perlcall>.
422
423 =for apidoc AmU||G_EVAL
424
425 Used to force a Perl C<eval> wrapper around a callback.  See
426 L<perlcall>.
427
428 =for apidoc AmU||G_NOARGS
429
430 Indicates that no arguments are being sent to a callback.  See
431 L<perlcall>.
432
433 =cut
434 */
435
436 #define G_SCALAR        0
437 #define G_ARRAY         1
438 #define G_VOID          128     /* skip this bit when adding flags below */
439
440 /* extra flags for Perl_call_* routines */
441 #define G_DISCARD       2       /* Call FREETMPS. */
442 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
443 #define G_NOARGS        8       /* Don't construct a @_ array. */
444 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
445 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
446 #define G_METHOD       64       /* Calling method. */
447
448 /* flag bits for PL_in_eval */
449 #define EVAL_NULL       0       /* not in an eval */
450 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
451 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
452 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
453 #define EVAL_INREQUIRE  8       /* The code is being required. */
454
455 /* Support for switching (stack and block) contexts.
456  * This ensures magic doesn't invalidate local stack and cx pointers.
457  */
458
459 #define PERLSI_UNKNOWN          -1
460 #define PERLSI_UNDEF            0
461 #define PERLSI_MAIN             1
462 #define PERLSI_MAGIC            2
463 #define PERLSI_SORT             3
464 #define PERLSI_SIGNAL           4
465 #define PERLSI_OVERLOAD         5
466 #define PERLSI_DESTROY          6
467 #define PERLSI_WARNHOOK         7
468 #define PERLSI_DIEHOOK          8
469 #define PERLSI_REQUIRE          9
470
471 struct stackinfo {
472     AV *                si_stack;       /* stack for current runlevel */
473     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
474     I32                 si_cxix;        /* current context index */
475     I32                 si_cxmax;       /* maximum allocated index */
476     I32                 si_type;        /* type of runlevel */
477     struct stackinfo *  si_prev;
478     struct stackinfo *  si_next;
479     I32                 si_markoff;     /* offset where markstack begins for us.
480                                          * currently used only with DEBUGGING,
481                                          * but not #ifdef-ed for bincompat */
482 };
483
484 typedef struct stackinfo PERL_SI;
485
486 #define cxstack         (PL_curstackinfo->si_cxstack)
487 #define cxstack_ix      (PL_curstackinfo->si_cxix)
488 #define cxstack_max     (PL_curstackinfo->si_cxmax)
489
490 #ifdef DEBUGGING
491 #  define       SET_MARK_OFFSET \
492     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
493 #else
494 #  define       SET_MARK_OFFSET NOOP
495 #endif
496
497 #define PUSHSTACKi(type) \
498     STMT_START {                                                        \
499         PERL_SI *next = PL_curstackinfo->si_next;                       \
500         if (!next) {                                                    \
501             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
502             next->si_prev = PL_curstackinfo;                            \
503             PL_curstackinfo->si_next = next;                            \
504         }                                                               \
505         next->si_type = type;                                           \
506         next->si_cxix = -1;                                             \
507         AvFILLp(next->si_stack) = 0;                                    \
508         SWITCHSTACK(PL_curstack,next->si_stack);                        \
509         PL_curstackinfo = next;                                         \
510         SET_MARK_OFFSET;                                                \
511     } STMT_END
512
513 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
514
515 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
516  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
517 #define POPSTACK \
518     STMT_START {                                                        \
519         dSP;                                                            \
520         PERL_SI *prev = PL_curstackinfo->si_prev;                       \
521         if (!prev) {                                                    \
522             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
523             my_exit(1);                                                 \
524         }                                                               \
525         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
526         /* don't free prev here, free them all at the END{} */          \
527         PL_curstackinfo = prev;                                         \
528     } STMT_END
529
530 #define POPSTACK_TO(s) \
531     STMT_START {                                                        \
532         while (PL_curstack != s) {                                      \
533             dounwind(-1);                                               \
534             POPSTACK;                                                   \
535         }                                                               \
536     } STMT_END