cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (c) 1991-2001, 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 = savepv(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 = ((pv) ? savepv(pv) : Nullch))
  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 #else
  48 #  define CopFILEGV(c)          ((c)->cop_filegv)
  49 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
  50 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
  51 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
  52 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
  53 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
  54 #  define CopSTASH(c)           ((c)->cop_stash)
  55 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
  56 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME(CopSTASH(c)) : Nullch)
  57    /* cop_stash is not refcounted */
  58 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
  59 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
  60 #endif /* USE_ITHREADS */
  61
  62 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
  63 #define CopLINE(c)              ((c)->cop_line)
  64 #define CopLINE_inc(c)          (++CopLINE(c))
  65 #define CopLINE_dec(c)          (--CopLINE(c))
  66 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
  67
  68 /*
  69  * Here we have some enormously heavy (or at least ponderous) wizardry.
  70  */
  71
  72 /* subroutine context */
  73 struct block_sub {
  74     CV *        cv;
  75     GV *        gv;
  76     GV *        dfoutgv;
  77 #ifndef USE_5005THREADS
  78     AV *        savearray;
  79 #endif /* USE_5005THREADS */
  80     AV *        argarray;
  81     U16         olddepth;
  82     U8          hasargs;
  83     U8          lval;           /* XXX merge lval and hasargs? */
  84     SV **       oldcurpad;
  85 };
  86
  87 #define PUSHSUB(cx)                                                     \
  88         cx->blk_sub.cv = cv;                                            \
  89         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
  90         cx->blk_sub.hasargs = hasargs;                                  \
  91         cx->blk_sub.lval = PL_op->op_private &                          \
  92                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
  93
  94 #define PUSHFORMAT(cx)                                                  \
  95         cx->blk_sub.cv = cv;                                            \
  96         cx->blk_sub.gv = gv;                                            \
  97         cx->blk_sub.hasargs = 0;                                        \
  98         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
  99         (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
 100
 101 #ifdef USE_5005THREADS
 102 #  define POP_SAVEARRAY() NOOP
 103 #else
 104 #  define POP_SAVEARRAY()                                               \
 105     STMT_START {                                                        \
 106         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 107         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 108     } STMT_END
 109 #endif /* USE_5005THREADS */
 110
 111 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 112  * leave any (a fast av_clear(ary), basically) */
 113 #define CLEAR_ARGARRAY(ary) \
 114     STMT_START {                                                        \
 115         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 116         SvPVX(ary) = (char*)AvALLOC(ary);                               \
 117         AvFILLp(ary) = -1;                                              \
 118     } STMT_END
 119
 120 #define POPSUB(cx,sv)                                                   \
 121     STMT_START {                                                        \
 122         if (cx->blk_sub.hasargs) {                                      \
 123             POP_SAVEARRAY();                                            \
 124             /* abandon @_ if it got reified */                          \
 125             if (AvREAL(cx->blk_sub.argarray)) {                         \
 126                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
 127                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 128                 cx->blk_sub.argarray = newAV();                         \
 129                 av_extend(cx->blk_sub.argarray, fill);                  \
 130                 AvFLAGS(cx->blk_sub.argarray) = AVf_REIFY;              \
 131                 cx->blk_sub.oldcurpad[0] = (SV*)cx->blk_sub.argarray;   \
 132             }                                                           \
 133             else {                                                      \
 134                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 135             }                                                           \
 136         }                                                               \
 137         sv = (SV*)cx->blk_sub.cv;                                       \
 138         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 139             sv = Nullsv;                                                \
 140     } STMT_END
 141
 142 #define LEAVESUB(sv)                                                    \
 143     STMT_START {                                                        \
 144         if (sv)                                                         \
 145             SvREFCNT_dec(sv);                                           \
 146     } STMT_END
 147
 148 #define POPFORMAT(cx)                                                   \
 149         setdefout(cx->blk_sub.dfoutgv);                                 \
 150         SvREFCNT_dec(cx->blk_sub.dfoutgv);
 151
 152 /* eval context */
 153 struct block_eval {
 154     I32         old_in_eval;
 155     I32         old_op_type;
 156     SV *        old_namesv;
 157     OP *        old_eval_root;
 158     SV *        cur_text;
 159     CV *        cv;
 160 };
 161
 162 #define PUSHEVAL(cx,n,fgv)                                              \
 163     STMT_START {                                                        \
 164         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 165         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 166         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);          \
 167         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 168         cx->blk_eval.cur_text = PL_linestr;                             \
 169         cx->blk_eval.cv = Nullcv; /* set by doeval(), as applicable */  \
 170     } STMT_END
 171
 172 #define POPEVAL(cx)                                                     \
 173     STMT_START {                                                        \
 174         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 175         optype = cx->blk_eval.old_op_type;                              \
 176         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 177         if (cx->blk_eval.old_namesv)                                    \
 178             sv_2mortal(cx->blk_eval.old_namesv);                        \
 179     } STMT_END
 180
 181 /* loop context */
 182 struct block_loop {
 183     char *      label;
 184     I32         resetsp;
 185     OP *        redo_op;
 186     OP *        next_op;
 187     OP *        last_op;
 188 #ifdef USE_ITHREADS
 189     void *      iterdata;
 190     SV **       oldcurpad;
 191 #else
 192     SV **       itervar;
 193 #endif
 194     SV *        itersave;
 195     SV *        iterlval;
 196     AV *        iterary;
 197     IV          iterix;
 198     IV          itermax;
 199 };
 200
 201 #ifdef USE_ITHREADS
 202 #  define CxITERVAR(c)                                                  \
 203         ((c)->blk_loop.iterdata                                         \
 204          ? (CxPADLOOP(cx)                                               \
 205             ? &((c)->blk_loop.oldcurpad)[INT2PTR(PADOFFSET, (c)->blk_loop.iterdata)] \
 206             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 207          : (SV**)NULL)
 208 #  define CX_ITERDATA_SET(cx,idata)                                     \
 209         cx->blk_loop.oldcurpad = PL_curpad;                             \
 210         if ((cx->blk_loop.iterdata = (idata)))                          \
 211             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 212 #else
 213 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 214 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 215         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 216             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));
 217 #endif
 218
 219 #define PUSHLOOP(cx, dat, s)                                            \
 220         cx->blk_loop.label = PL_curcop->cop_label;                      \
 221         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 222         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
 223         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
 224         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
 225         cx->blk_loop.iterlval = Nullsv;                                 \
 226         cx->blk_loop.iterary = Nullav;                                  \
 227         cx->blk_loop.iterix = -1;                                       \
 228         CX_ITERDATA_SET(cx,dat);
 229
 230 #define POPLOOP(cx)                                                     \
 231         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 232         if (CxITERVAR(cx)) {                                            \
 233             SV **s_v_p = CxITERVAR(cx);                                 \
 234             sv_2mortal(*s_v_p);                                         \
 235             *s_v_p = cx->blk_loop.itersave;                             \
 236         }                                                               \
 237         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 238             SvREFCNT_dec(cx->blk_loop.iterary);
 239
 240 /* context common to subroutines, evals and loops */
 241 struct block {
 242     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 243     COP *       blku_oldcop;    /* old curcop pointer */
 244     I32         blku_oldretsp;  /* return stack index */
 245     I32         blku_oldmarksp; /* mark stack index */
 246     I32         blku_oldscopesp;        /* scope stack index */
 247     PMOP *      blku_oldpm;     /* values of pattern match vars */
 248     U8          blku_gimme;     /* is this block running in list context? */
 249
 250     union {
 251         struct block_sub        blku_sub;
 252         struct block_eval       blku_eval;
 253         struct block_loop       blku_loop;
 254     } blk_u;
 255 };
 256 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 257 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 258 #define blk_oldretsp    cx_u.cx_blk.blku_oldretsp
 259 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 260 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 261 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 262 #define blk_gimme       cx_u.cx_blk.blku_gimme
 263 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 264 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 265 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 266
 267 /* Enter a block. */
 268 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 269         cx->cx_type             = t,                                    \
 270         cx->blk_oldsp           = sp - PL_stack_base,                   \
 271         cx->blk_oldcop          = PL_curcop,                            \
 272         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 273         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 274         cx->blk_oldretsp        = PL_retstack_ix,                       \
 275         cx->blk_oldpm           = PL_curpm,                             \
 276         cx->blk_gimme           = gimme;                                \
 277         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 278                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 279
 280 /* Exit a block (RETURN and LAST). */
 281 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 282         newsp            = PL_stack_base + cx->blk_oldsp,               \
 283         PL_curcop        = cx->blk_oldcop,                              \
 284         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 285         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 286         PL_retstack_ix   = cx->blk_oldretsp,                            \
 287         pm               = cx->blk_oldpm,                               \
 288         gimme            = cx->blk_gimme;                               \
 289         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 290                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 291
 292 /* Continue a block elsewhere (NEXT and REDO). */
 293 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 294         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 295         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 296         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 297         PL_retstack_ix   = cx->blk_oldretsp,                            \
 298         PL_curpm         = cx->blk_oldpm
 299
 300 /* substitution context */
 301 struct subst {
 302     I32         sbu_iters;
 303     I32         sbu_maxiters;
 304     I32         sbu_rflags;
 305     I32         sbu_oldsave;
 306     bool        sbu_once;
 307     bool        sbu_rxtainted;
 308     char *      sbu_orig;
 309     SV *        sbu_dstr;
 310     SV *        sbu_targ;
 311     char *      sbu_s;
 312     char *      sbu_m;
 313     char *      sbu_strend;
 314     void *      sbu_rxres;
 315     REGEXP *    sbu_rx;
 316 };
 317 #define sb_iters        cx_u.cx_subst.sbu_iters
 318 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 319 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 320 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 321 #define sb_once         cx_u.cx_subst.sbu_once
 322 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 323 #define sb_orig         cx_u.cx_subst.sbu_orig
 324 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 325 #define sb_targ         cx_u.cx_subst.sbu_targ
 326 #define sb_s            cx_u.cx_subst.sbu_s
 327 #define sb_m            cx_u.cx_subst.sbu_m
 328 #define sb_strend       cx_u.cx_subst.sbu_strend
 329 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 330 #define sb_rx           cx_u.cx_subst.sbu_rx
 331
 332 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 333         cx->sb_iters            = iters,                                \
 334         cx->sb_maxiters         = maxiters,                             \
 335         cx->sb_rflags           = r_flags,                              \
 336         cx->sb_oldsave          = oldsave,                              \
 337         cx->sb_once             = once,                                 \
 338         cx->sb_rxtainted        = rxtainted,                            \
 339         cx->sb_orig             = orig,                                 \
 340         cx->sb_dstr             = dstr,                                 \
 341         cx->sb_targ             = targ,                                 \
 342         cx->sb_s                = s,                                    \
 343         cx->sb_m                = m,                                    \
 344         cx->sb_strend           = strend,                               \
 345         cx->sb_rxres            = Null(void*),                          \
 346         cx->sb_rx               = rx,                                   \
 347         cx->cx_type             = CXt_SUBST;                            \
 348         rxres_save(&cx->sb_rxres, rx)
 349
 350 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 351         rxres_free(&cx->sb_rxres)
 352
 353 struct context {
 354     U32         cx_type;        /* what kind of context this is */
 355     union {
 356         struct block    cx_blk;
 357         struct subst    cx_subst;
 358     } cx_u;
 359 };
 360
 361 #define CXTYPEMASK      0xff
 362 #define CXt_NULL        0
 363 #define CXt_SUB         1
 364 #define CXt_EVAL        2
 365 #define CXt_LOOP        3
 366 #define CXt_SUBST       4
 367 #define CXt_BLOCK       5
 368 #define CXt_FORMAT      6
 369
 370 /* private flags for CXt_EVAL */
 371 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 372 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 373
 374 #ifdef USE_ITHREADS
 375 /* private flags for CXt_LOOP */
 376 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 377                                            has pad offset; if not set,
 378                                            iterdata holds GV* */
 379 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 380                          == (CXt_LOOP|CXp_PADVAR))
 381 #endif
 382
 383 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 384 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
 385                          == (CXt_EVAL|CXp_REAL))
 386 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
 387                          == (CXt_EVAL|CXp_TRYBLOCK))
 388
 389 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 390
 391 /* "gimme" values */
 392
 393 /*
 394 =for apidoc AmU||G_SCALAR
 395 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 396 L<perlcall>.
 397
 398 =for apidoc AmU||G_ARRAY
 399 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 400 L<perlcall>.
 401
 402 =for apidoc AmU||G_VOID
 403 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 404
 405 =for apidoc AmU||G_DISCARD
 406 Indicates that arguments returned from a callback should be discarded.  See
 407 L<perlcall>.
 408
 409 =for apidoc AmU||G_EVAL
 410
 411 Used to force a Perl C<eval> wrapper around a callback.  See
 412 L<perlcall>.
 413
 414 =for apidoc AmU||G_NOARGS
 415
 416 Indicates that no arguments are being sent to a callback.  See
 417 L<perlcall>.
 418
 419 =cut
 420 */
 421
 422 #define G_SCALAR        0
 423 #define G_ARRAY         1
 424 #define G_VOID          128     /* skip this bit when adding flags below */
 425
 426 /* extra flags for Perl_call_* routines */
 427 #define G_DISCARD       2       /* Call FREETMPS. */
 428 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 429 #define G_NOARGS        8       /* Don't construct a @_ array. */
 430 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 431 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 432 #define G_METHOD       64       /* Calling method. */
 433
 434 /* flag bits for PL_in_eval */
 435 #define EVAL_NULL       0       /* not in an eval */
 436 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 437 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 438 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 439 #define EVAL_INREQUIRE  8       /* The code is being required. */
 440
 441 /* Support for switching (stack and block) contexts.
 442  * This ensures magic doesn't invalidate local stack and cx pointers.
 443  */
 444
 445 #define PERLSI_UNKNOWN          -1
 446 #define PERLSI_UNDEF            0
 447 #define PERLSI_MAIN             1
 448 #define PERLSI_MAGIC            2
 449 #define PERLSI_SORT             3
 450 #define PERLSI_SIGNAL           4
 451 #define PERLSI_OVERLOAD         5
 452 #define PERLSI_DESTROY          6
 453 #define PERLSI_WARNHOOK         7
 454 #define PERLSI_DIEHOOK          8
 455 #define PERLSI_REQUIRE          9
 456
 457 struct stackinfo {
 458     AV *                si_stack;       /* stack for current runlevel */
 459     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 460     I32                 si_cxix;        /* current context index */
 461     I32                 si_cxmax;       /* maximum allocated index */
 462     I32                 si_type;        /* type of runlevel */
 463     struct stackinfo *  si_prev;
 464     struct stackinfo *  si_next;
 465     I32                 si_markoff;     /* offset where markstack begins for us.
 466                                          * currently used only with DEBUGGING,
 467                                          * but not #ifdef-ed for bincompat */
 468 };
 469
 470 typedef struct stackinfo PERL_SI;
 471
 472 #define cxstack         (PL_curstackinfo->si_cxstack)
 473 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 474 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 475
 476 #ifdef DEBUGGING
 477 #  define       SET_MARK_OFFSET \
 478     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 479 #else
 480 #  define       SET_MARK_OFFSET NOOP
 481 #endif
 482
 483 #define PUSHSTACKi(type) \
 484     STMT_START {                                                        \
 485         PERL_SI *next = PL_curstackinfo->si_next;                       \
 486         if (!next) {                                                    \
 487             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 488             next->si_prev = PL_curstackinfo;                            \
 489             PL_curstackinfo->si_next = next;                            \
 490         }                                                               \
 491         next->si_type = type;                                           \
 492         next->si_cxix = -1;                                             \
 493         AvFILLp(next->si_stack) = 0;                                    \
 494         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 495         PL_curstackinfo = next;                                         \
 496         SET_MARK_OFFSET;                                                \
 497     } STMT_END
 498
 499 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 500
 501 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 502  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 503 #define POPSTACK \
 504     STMT_START {                                                        \
 505         dSP;                                                            \
 506         PERL_SI *prev = PL_curstackinfo->si_prev;                       \
 507         if (!prev) {                                                    \
 508             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 509             my_exit(1);                                                 \
 510         }                                                               \
 511         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 512         /* don't free prev here, free them all at the END{} */          \
 513         PL_curstackinfo = prev;                                         \
 514     } STMT_END
 515
 516 #define POPSTACK_TO(s) \
 517     STMT_START {                                                        \
 518         while (PL_curstack != s) {                                      \
 519             dounwind(-1);                                               \
 520             POPSTACK;                                                   \
 521         }                                                               \
 522     } STMT_END