cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (c) 1991-2000, 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 };
  25
  26 #define Nullcop Null(COP*)
  27
  28 #ifdef USE_ITHREADS
  29 #  define CopFILE(c)            ((c)->cop_file)
  30 #  define CopFILEGV(c)          (CopFILE(c) \
  31                                  ? gv_fetchfile(CopFILE(c)) : Nullgv)
  32 #  define CopFILE_set(c,pv)     ((c)->cop_file = savepv(pv))
  33 #  define CopFILESV(c)          (CopFILE(c) \
  34                                  ? GvSV(gv_fetchfile(CopFILE(c))) : Nullsv)
  35 #  define CopFILEAV(c)          (CopFILE(c) \
  36                                  ? GvAV(gv_fetchfile(CopFILE(c))) : Nullav)
  37 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
  38 #  define CopSTASHPV_set(c,pv)  ((c)->cop_stashpv = savepv(pv))
  39 #  define CopSTASH(c)           (CopSTASHPV(c) \
  40                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : Nullhv)
  41 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, HvNAME(hv))
  42 #  define CopSTASH_eq(c,hv)     ((hv)                                   \
  43                                  && (CopSTASHPV(c) == HvNAME(hv)        \
  44                                      || (CopSTASHPV(c) && HvNAME(hv)    \
  45                                          && strEQ(CopSTASHPV(c), HvNAME(hv)))))
  46 #else
  47 #  define CopFILEGV(c)          ((c)->cop_filegv)
  48 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
  49 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
  50 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
  51 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
  52 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
  53 #  define CopSTASH(c)           ((c)->cop_stash)
  54 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
  55 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME(CopSTASH(c)) : Nullch)
  56    /* cop_stash is not refcounted */
  57 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
  58 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
  59 #endif /* USE_ITHREADS */
  60
  61 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
  62 #define CopLINE(c)              ((c)->cop_line)
  63 #define CopLINE_inc(c)          (++CopLINE(c))
  64 #define CopLINE_dec(c)          (--CopLINE(c))
  65 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
  66
  67 /*
  68  * Here we have some enormously heavy (or at least ponderous) wizardry.
  69  */
  70
  71 /* subroutine context */
  72 struct block_sub {
  73     CV *        cv;
  74     GV *        gv;
  75     GV *        dfoutgv;
  76 #ifndef USE_THREADS
  77     AV *        savearray;
  78 #endif /* USE_THREADS */
  79     AV *        argarray;
  80     U16         olddepth;
  81     U8          hasargs;
  82     U8          lval;           /* XXX merge lval and hasargs? */
  83 };
  84
  85 #define PUSHSUB(cx)                                                     \
  86         cx->blk_sub.cv = cv;                                            \
  87         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
  88         cx->blk_sub.hasargs = hasargs;                                  \
  89         cx->blk_sub.lval = PL_op->op_private &                          \
  90                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
  91
  92 #define PUSHFORMAT(cx)                                                  \
  93         cx->blk_sub.cv = cv;                                            \
  94         cx->blk_sub.gv = gv;                                            \
  95         cx->blk_sub.hasargs = 0;                                        \
  96         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
  97         (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
  98
  99 #ifdef USE_THREADS
 100 #  define POP_SAVEARRAY() NOOP
 101 #else
 102 #  define POP_SAVEARRAY()                                               \
 103     STMT_START {                                                        \
 104         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 105         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 106     } STMT_END
 107 #endif /* USE_THREADS */
 108
 109 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 110  * leave any */
 111 #define CLEAR_ARGARRAY()        av_clear(cx->blk_sub.argarray)
 112
 113 #define POPSUB(cx,sv)                                                   \
 114     STMT_START {                                                        \
 115         if (cx->blk_sub.hasargs) {                                      \
 116             POP_SAVEARRAY();                                            \
 117             /* abandon @_ if it got reified */                          \
 118             if (AvREAL(cx->blk_sub.argarray)) {                         \
 119                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
 120                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 121                 cx->blk_sub.argarray = newAV();                         \
 122                 av_extend(cx->blk_sub.argarray, fill);                  \
 123                 AvFLAGS(cx->blk_sub.argarray) = AVf_REIFY;              \
 124                 PL_curpad[0] = (SV*)cx->blk_sub.argarray;               \
 125             }                                                           \
 126             else {                                                      \
 127                 CLEAR_ARGARRAY();                                       \
 128             }                                                           \
 129         }                                                               \
 130         sv = (SV*)cx->blk_sub.cv;                                       \
 131         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 132             sv = Nullsv;                                                \
 133     } STMT_END
 134
 135 #define LEAVESUB(sv)                                                    \
 136     STMT_START {                                                        \
 137         if (sv)                                                         \
 138             SvREFCNT_dec(sv);                                           \
 139     } STMT_END
 140
 141 #define POPFORMAT(cx)                                                   \
 142         setdefout(cx->blk_sub.dfoutgv);                                 \
 143         SvREFCNT_dec(cx->blk_sub.dfoutgv);
 144
 145 /* eval context */
 146 struct block_eval {
 147     I32         old_in_eval;
 148     I32         old_op_type;
 149     SV *        old_namesv;
 150     OP *        old_eval_root;
 151     SV *        cur_text;
 152 };
 153
 154 #define PUSHEVAL(cx,n,fgv)                                              \
 155     STMT_START {                                                        \
 156         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 157         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 158         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);          \
 159         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 160         cx->blk_eval.cur_text = PL_linestr;                             \
 161     } STMT_END
 162
 163 #define POPEVAL(cx)                                                     \
 164     STMT_START {                                                        \
 165         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 166         optype = cx->blk_eval.old_op_type;                              \
 167         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 168         if (cx->blk_eval.old_namesv)                                    \
 169             sv_2mortal(cx->blk_eval.old_namesv);                        \
 170     } STMT_END
 171
 172 /* loop context */
 173 struct block_loop {
 174     char *      label;
 175     I32         resetsp;
 176     OP *        redo_op;
 177     OP *        next_op;
 178     OP *        last_op;
 179 #ifdef USE_ITHREADS
 180     void *      iterdata;
 181     SV **       oldcurpad;
 182 #else
 183     SV **       itervar;
 184 #endif
 185     SV *        itersave;
 186     SV *        iterlval;
 187     AV *        iterary;
 188     IV          iterix;
 189     IV          itermax;
 190 };
 191
 192 #ifdef USE_ITHREADS
 193 #  define CxITERVAR(c)                                                  \
 194         ((c)->blk_loop.iterdata                                         \
 195          ? (CxPADLOOP(cx)                                               \
 196             ? &((c)->blk_loop.oldcurpad)[(PADOFFSET)(c)->blk_loop.iterdata]     \
 197             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 198          : (SV**)NULL)
 199 #  define CX_ITERDATA_SET(cx,idata)                                     \
 200         cx->blk_loop.oldcurpad = PL_curpad;                             \
 201         if ((cx->blk_loop.iterdata = (idata)))                          \
 202             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 203 #else
 204 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 205 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 206         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 207             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 208 #endif
 209
 210 #define PUSHLOOP(cx, dat, s)                                            \
 211         cx->blk_loop.label = PL_curcop->cop_label;                      \
 212         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 213         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
 214         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
 215         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
 216         cx->blk_loop.iterlval = Nullsv;                                 \
 217         cx->blk_loop.iterary = Nullav;                                  \
 218         cx->blk_loop.iterix = -1;                                       \
 219         CX_ITERDATA_SET(cx,dat);
 220
 221 #define POPLOOP(cx)                                                     \
 222         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 223         if (CxITERVAR(cx)) {                                            \
 224             SV **s_v_p = CxITERVAR(cx);                                 \
 225             sv_2mortal(*s_v_p);                                         \
 226             *s_v_p = cx->blk_loop.itersave;                             \
 227         }                                                               \
 228         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 229             SvREFCNT_dec(cx->blk_loop.iterary);
 230
 231 /* context common to subroutines, evals and loops */
 232 struct block {
 233     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 234     COP *       blku_oldcop;    /* old curcop pointer */
 235     I32         blku_oldretsp;  /* return stack index */
 236     I32         blku_oldmarksp; /* mark stack index */
 237     I32         blku_oldscopesp;        /* scope stack index */
 238     PMOP *      blku_oldpm;     /* values of pattern match vars */
 239     U8          blku_gimme;     /* is this block running in list context? */
 240
 241     union {
 242         struct block_sub        blku_sub;
 243         struct block_eval       blku_eval;
 244         struct block_loop       blku_loop;
 245     } blk_u;
 246 };
 247 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 248 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 249 #define blk_oldretsp    cx_u.cx_blk.blku_oldretsp
 250 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 251 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 252 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 253 #define blk_gimme       cx_u.cx_blk.blku_gimme
 254 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 255 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 256 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 257
 258 /* Enter a block. */
 259 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 260         cx->cx_type             = t,                                    \
 261         cx->blk_oldsp           = sp - PL_stack_base,                   \
 262         cx->blk_oldcop          = PL_curcop,                            \
 263         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 264         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 265         cx->blk_oldretsp        = PL_retstack_ix,                       \
 266         cx->blk_oldpm           = PL_curpm,                             \
 267         cx->blk_gimme           = gimme;                                \
 268         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 269                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 270
 271 /* Exit a block (RETURN and LAST). */
 272 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 273         newsp            = PL_stack_base + cx->blk_oldsp,               \
 274         PL_curcop        = cx->blk_oldcop,                              \
 275         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 276         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 277         PL_retstack_ix   = cx->blk_oldretsp,                            \
 278         pm               = cx->blk_oldpm,                               \
 279         gimme            = cx->blk_gimme;                               \
 280         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 281                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 282
 283 /* Continue a block elsewhere (NEXT and REDO). */
 284 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 285         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 286         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 287         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 288         PL_retstack_ix   = cx->blk_oldretsp,                            \
 289         PL_curpm         = cx->blk_oldpm
 290
 291 /* substitution context */
 292 struct subst {
 293     I32         sbu_iters;
 294     I32         sbu_maxiters;
 295     I32         sbu_rflags;
 296     I32         sbu_oldsave;
 297     bool        sbu_once;
 298     bool        sbu_rxtainted;
 299     char *      sbu_orig;
 300     SV *        sbu_dstr;
 301     SV *        sbu_targ;
 302     char *      sbu_s;
 303     char *      sbu_m;
 304     char *      sbu_strend;
 305     void *      sbu_rxres;
 306     REGEXP *    sbu_rx;
 307 };
 308 #define sb_iters        cx_u.cx_subst.sbu_iters
 309 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 310 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 311 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 312 #define sb_once         cx_u.cx_subst.sbu_once
 313 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 314 #define sb_orig         cx_u.cx_subst.sbu_orig
 315 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 316 #define sb_targ         cx_u.cx_subst.sbu_targ
 317 #define sb_s            cx_u.cx_subst.sbu_s
 318 #define sb_m            cx_u.cx_subst.sbu_m
 319 #define sb_strend       cx_u.cx_subst.sbu_strend
 320 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 321 #define sb_rx           cx_u.cx_subst.sbu_rx
 322
 323 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 324         cx->sb_iters            = iters,                                \
 325         cx->sb_maxiters         = maxiters,                             \
 326         cx->sb_rflags           = r_flags,                              \
 327         cx->sb_oldsave          = oldsave,                              \
 328         cx->sb_once             = once,                                 \
 329         cx->sb_rxtainted        = rxtainted,                            \
 330         cx->sb_orig             = orig,                                 \
 331         cx->sb_dstr             = dstr,                                 \
 332         cx->sb_targ             = targ,                                 \
 333         cx->sb_s                = s,                                    \
 334         cx->sb_m                = m,                                    \
 335         cx->sb_strend           = strend,                               \
 336         cx->sb_rxres            = Null(void*),                          \
 337         cx->sb_rx               = rx,                                   \
 338         cx->cx_type             = CXt_SUBST;                            \
 339         rxres_save(&cx->sb_rxres, rx)
 340
 341 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 342         rxres_free(&cx->sb_rxres)
 343
 344 struct context {
 345     U32         cx_type;        /* what kind of context this is */
 346     union {
 347         struct block    cx_blk;
 348         struct subst    cx_subst;
 349     } cx_u;
 350 };
 351
 352 #define CXTYPEMASK      0xff
 353 #define CXt_NULL        0
 354 #define CXt_SUB         1
 355 #define CXt_EVAL        2
 356 #define CXt_LOOP        3
 357 #define CXt_SUBST       4
 358 #define CXt_BLOCK       5
 359 #define CXt_FORMAT      6
 360
 361 /* private flags for CXt_EVAL */
 362 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 363 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 364
 365 #ifdef USE_ITHREADS
 366 /* private flags for CXt_LOOP */
 367 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 368                                            has pad offset; if not set,
 369                                            iterdata holds GV* */
 370 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 371                          == (CXt_LOOP|CXp_PADVAR))
 372 #endif
 373
 374 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 375 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
 376                          == (CXt_EVAL|CXp_REAL))
 377 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
 378                          == (CXt_EVAL|CXp_TRYBLOCK))
 379
 380 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 381
 382 /* "gimme" values */
 383
 384 /*
 385 =for apidoc AmU||G_SCALAR
 386 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 387 L<perlcall>.
 388
 389 =for apidoc AmU||G_ARRAY
 390 Used to indicate array context.  See C<GIMME_V>, C<GIMME> and
 391 L<perlcall>.
 392
 393 =for apidoc AmU||G_VOID
 394 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 395
 396 =for apidoc AmU||G_DISCARD
 397 Indicates that arguments returned from a callback should be discarded.  See
 398 L<perlcall>.
 399
 400 =for apidoc AmU||G_EVAL
 401
 402 Used to force a Perl C<eval> wrapper around a callback.  See
 403 L<perlcall>.
 404
 405 =for apidoc AmU||G_NOARGS
 406
 407 Indicates that no arguments are being sent to a callback.  See
 408 L<perlcall>.
 409
 410 =cut
 411 */
 412
 413 #define G_SCALAR        0
 414 #define G_ARRAY         1
 415 #define G_VOID          128     /* skip this bit when adding flags below */
 416
 417 /* extra flags for Perl_call_* routines */
 418 #define G_DISCARD       2       /* Call FREETMPS. */
 419 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 420 #define G_NOARGS        8       /* Don't construct a @_ array. */
 421 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 422 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 423 #define G_METHOD       64       /* Calling method. */
 424
 425 /* flag bits for PL_in_eval */
 426 #define EVAL_NULL       0       /* not in an eval */
 427 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 428 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 429 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 430
 431 /* Support for switching (stack and block) contexts.
 432  * This ensures magic doesn't invalidate local stack and cx pointers.
 433  */
 434
 435 #define PERLSI_UNKNOWN          -1
 436 #define PERLSI_UNDEF            0
 437 #define PERLSI_MAIN             1
 438 #define PERLSI_MAGIC            2
 439 #define PERLSI_SORT             3
 440 #define PERLSI_SIGNAL           4
 441 #define PERLSI_OVERLOAD         5
 442 #define PERLSI_DESTROY          6
 443 #define PERLSI_WARNHOOK         7
 444 #define PERLSI_DIEHOOK          8
 445 #define PERLSI_REQUIRE          9
 446
 447 struct stackinfo {
 448     AV *                si_stack;       /* stack for current runlevel */
 449     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 450     I32                 si_cxix;        /* current context index */
 451     I32                 si_cxmax;       /* maximum allocated index */
 452     I32                 si_type;        /* type of runlevel */
 453     struct stackinfo *  si_prev;
 454     struct stackinfo *  si_next;
 455     I32                 si_markoff;     /* offset where markstack begins for us.
 456                                          * currently used only with DEBUGGING,
 457                                          * but not #ifdef-ed for bincompat */
 458 };
 459
 460 typedef struct stackinfo PERL_SI;
 461
 462 #define cxstack         (PL_curstackinfo->si_cxstack)
 463 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 464 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 465
 466 #ifdef DEBUGGING
 467 #  define       SET_MARK_OFFSET \
 468     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 469 #else
 470 #  define       SET_MARK_OFFSET NOOP
 471 #endif
 472
 473 #define PUSHSTACKi(type) \
 474     STMT_START {                                                        \
 475         PERL_SI *next = PL_curstackinfo->si_next;                       \
 476         if (!next) {                                                    \
 477             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 478             next->si_prev = PL_curstackinfo;                            \
 479             PL_curstackinfo->si_next = next;                            \
 480         }                                                               \
 481         next->si_type = type;                                           \
 482         next->si_cxix = -1;                                             \
 483         AvFILLp(next->si_stack) = 0;                                    \
 484         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 485         PL_curstackinfo = next;                                         \
 486         SET_MARK_OFFSET;                                                \
 487     } STMT_END
 488
 489 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 490
 491 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 492  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 493 #define POPSTACK \
 494     STMT_START {                                                        \
 495         djSP;                                                           \
 496         PERL_SI *prev = PL_curstackinfo->si_prev;                       \
 497         if (!prev) {                                                    \
 498             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 499             my_exit(1);                                                 \
 500         }                                                               \
 501         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 502         /* don't free prev here, free them all at the END{} */          \
 503         PL_curstackinfo = prev;                                         \
 504     } STMT_END
 505
 506 #define POPSTACK_TO(s) \
 507     STMT_START {                                                        \
 508         while (PL_curstack != s) {                                      \
 509             dounwind(-1);                                               \
 510             POPSTACK;                                                   \
 511         }                                                               \
 512     } STMT_END