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