cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   4  *    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
   5  *
   6  *    You may distribute under the terms of either the GNU General Public
   7  *    License or the Artistic License, as specified in the README file.
   8  *
   9  * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
  10  * and OP_SETSTATE that (loosely speaking) are separate statements.
  11  * They hold information important for lexical state and error reporting.
  12  * At run time, PL_curcop is set to point to the most recently executed cop,
  13  * and thus can be used to determine our current state.
  14  */
  15
  16 /* A jmpenv packages the state required to perform a proper non-local jump.
  17  * Note that there is a start_env initialized when perl starts, and top_env
  18  * points to this initially, so top_env should always be non-null.
  19  *
  20  * Existence of a non-null top_env->je_prev implies it is valid to call
  21  * longjmp() at that runlevel (we make sure start_env.je_prev is always
  22  * null to ensure this).
  23  *
  24  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
  25  * establish a local jmpenv to handle exception traps.  Care must be taken
  26  * to restore the previous value of je_mustcatch before exiting the
  27  * stack frame iff JMPENV_PUSH was not called in that stack frame.
  28  * GSAR 97-03-27
  29  */
  30
  31 struct jmpenv {
  32     struct jmpenv *     je_prev;
  33     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
  34     int                 je_ret;         /* last exception thrown */
  35     bool                je_mustcatch;   /* need to call longjmp()? */
  36 };
  37
  38 typedef struct jmpenv JMPENV;
  39
  40 #ifdef OP_IN_REGISTER
  41 #define OP_REG_TO_MEM   PL_opsave = op
  42 #define OP_MEM_TO_REG   op = PL_opsave
  43 #else
  44 #define OP_REG_TO_MEM   NOOP
  45 #define OP_MEM_TO_REG   NOOP
  46 #endif
  47
  48 /*
  49  * How to build the first jmpenv.
  50  *
  51  * top_env needs to be non-zero. It points to an area
  52  * in which longjmp() stuff is stored, as C callstack
  53  * info there at least is thread specific this has to
  54  * be per-thread. Otherwise a 'die' in a thread gives
  55  * that thread the C stack of last thread to do an eval {}!
  56  */
  57
  58 #define JMPENV_BOOTSTRAP \
  59     STMT_START {                                \
  60         Zero(&PL_start_env, 1, JMPENV);         \
  61         PL_start_env.je_ret = -1;               \
  62         PL_start_env.je_mustcatch = TRUE;       \
  63         PL_top_env = &PL_start_env;             \
  64     } STMT_END
  65
  66 /*
  67  *   PERL_FLEXIBLE_EXCEPTIONS
  68  *
  69  * All the flexible exceptions code has been removed.
  70  * See the following threads for details:
  71  *
  72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
  73  *
  74  * Joshua's original patches (which weren't applied) and discussion:
  75  *
  76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
  77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
  78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
  79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
  80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
  81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
  82  *
  83  * Chip's reworked patch and discussion:
  84  *
  85  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
  86  *
  87  * The flaw in these patches (which went unnoticed at the time) was
  88  * that they moved some code that could potentially die() out of the
  89  * region protected by the setjmp()s.  This caused exceptions within
  90  * END blocks and such to not be handled by the correct setjmp().
  91  *
  92  * The original patches that introduces flexible exceptions were:
  93  *
  94  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
  95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
  96  */
  97
  98 #define dJMPENV         JMPENV cur_env
  99
 100 #define JMPENV_PUSH(v) \
 101     STMT_START {                                                        \
 102         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
 103                          (void*)&cur_env, (void*)PL_top_env));                  \
 104         cur_env.je_prev = PL_top_env;                                   \
 105         OP_REG_TO_MEM;                                                  \
 106         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 107         OP_MEM_TO_REG;                                                  \
 108         PL_top_env = &cur_env;                                          \
 109         cur_env.je_mustcatch = FALSE;                                   \
 110         (v) = cur_env.je_ret;                                           \
 111     } STMT_END
 112
 113 #define JMPENV_POP \
 114     STMT_START {                                                        \
 115         DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
 116                          (void*)PL_top_env, (void*)cur_env.je_prev));                   \
 117         PL_top_env = cur_env.je_prev;                                   \
 118     } STMT_END
 119
 120 #define JMPENV_JUMP(v) \
 121     STMT_START {                                                \
 122         OP_REG_TO_MEM;                                          \
 123         if (PL_top_env->je_prev)                                \
 124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 125         if ((v) == 2)                                           \
 126             PerlProc_exit(STATUS_EXIT);                         \
 127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 128         PerlProc_exit(1);                                       \
 129     } STMT_END
 130
 131 #define CATCH_GET               (PL_top_env->je_mustcatch)
 132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
 133
 134
 135 #include "mydtrace.h"
 136
 137 struct cop {
 138     BASEOP
 139     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
 140        an exact multiple of 8 bytes to save structure padding.  */
 141     line_t      cop_line;       /* line # of this command */
 142     char *      cop_label;      /* label for this construct */
 143 #ifdef USE_ITHREADS
 144     char *      cop_stashpv;    /* package line was compiled in */
 145     char *      cop_file;       /* file name the following line # is from */
 146 #else
 147     HV *        cop_stash;      /* package line was compiled in */
 148     GV *        cop_filegv;     /* file the following line # is from */
 149 #endif
 150     U32         cop_hints;      /* hints bits from pragmata */
 151     U32         cop_seq;        /* parse sequence number */
 152     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 153     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 154     /* compile time state of %^H.  See the comment in op.c for how this is
 155        used to recreate a hash to return from caller.  */
 156     struct refcounted_he * cop_hints_hash;
 157 };
 158
 159 #ifdef USE_ITHREADS
 160 #  define CopFILE(c)            ((c)->cop_file)
 161 #  define CopFILEGV(c)          (CopFILE(c) \
 162                                  ? gv_fetchfile(CopFILE(c)) : NULL)
 163
 164 #  ifdef NETWARE
 165 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
 166 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
 167 #  else
 168 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
 169 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
 170 #  endif
 171
 172 #  define CopFILESV(c)          (CopFILE(c) \
 173                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 174 #  define CopFILEAV(c)          (CopFILE(c) \
 175                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
 176 #  ifdef DEBUGGING
 177 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
 178                                    GvAV(gv_fetchfile(CopFILE(c))))
 179 #  else
 180 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
 181 #  endif
 182 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
 183
 184 #  ifdef NETWARE
 185 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
 186 #  else
 187 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
 188 #  endif
 189
 190 #  define CopSTASH(c)           (CopSTASHPV(c) \
 191                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
 192 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
 193 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
 194 #  define CopLABEL(c)           ((c)->cop_label)
 195 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
 196 #  ifdef NETWARE
 197 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
 198 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
 199 #    define CopLABEL_free(c) SAVECOPLABEL_FREE(c)
 200 #    define CopLABEL_alloc(pv)  ((pv)?savepv(pv):NULL)
 201 #  else
 202 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
 203 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
 204 #    define CopLABEL_free(c)    (PerlMemShared_free(CopLABEL(c)),(CopLABEL(c) = NULL))
 205 #    define CopLABEL_alloc(pv)  ((pv)?savesharedpv(pv):NULL)
 206 #  endif
 207 #else
 208 #  define CopFILEGV(c)          ((c)->cop_filegv)
 209 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 210 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
 211 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
 212 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
 213 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
 214 #  ifdef DEBUGGING
 215 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
 216 #  else
 217 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
 218 # endif
 219 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
 220                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
 221 #  define CopSTASH(c)           ((c)->cop_stash)
 222 #  define CopLABEL(c)           ((c)->cop_label)
 223 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
 224 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
 225    /* cop_stash is not refcounted */
 226 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 227 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
 228 #  define CopLABEL_alloc(pv)    ((pv)?savepv(pv):NULL)
 229 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
 230 #  define CopSTASH_free(c)
 231 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
 232 #  define CopLABEL_free(c)      (Safefree(CopLABEL(c)),(CopLABEL(c) = NULL))
 233
 234 #endif /* USE_ITHREADS */
 235
 236 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
 237 #define CopLINE(c)              ((c)->cop_line)
 238 #define CopLINE_inc(c)          (++CopLINE(c))
 239 #define CopLINE_dec(c)          (--CopLINE(c))
 240 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
 241
 242 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
 243 #ifdef MACOS_TRADITIONAL
 244 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
 245 #else
 246 #  define OutCopFILE(c) CopFILE(c)
 247 #endif
 248
 249 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
 250    HINT_ARYBASE is set to indicate this.
 251    Setting it is ineficient due to the need to create 2 mortal SVs, but as
 252    using $[ is highly discouraged, no sane Perl code will be using it.  */
 253 #define CopARYBASE_get(c)       \
 254         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
 255          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
 256                                          "$[", 2, 0, 0))                \
 257          : 0)
 258 #define CopARYBASE_set(c, b) STMT_START { \
 259         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
 260             (c)->cop_hints |= HINT_ARYBASE;                             \
 261             if ((c) == &PL_compiling)                                   \
 262                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
 263             (c)->cop_hints_hash                                         \
 264                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
 265                                         newSVpvs_flags("$[", SVs_TEMP), \
 266                                         sv_2mortal(newSViv(b)));        \
 267         }                                                               \
 268     } STMT_END
 269
 270 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
 271 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
 272 #define CopHINTS_set(c, h)      STMT_START {                            \
 273                                     (c)->cop_hints = (h);               \
 274                                 } STMT_END
 275
 276 /*
 277  * Here we have some enormously heavy (or at least ponderous) wizardry.
 278  */
 279
 280 /* subroutine context */
 281 struct block_sub {
 282     CV *        cv;
 283     GV *        gv;
 284     GV *        dfoutgv;
 285     AV *        savearray;
 286     AV *        argarray;
 287     I32         olddepth;
 288     U8          hasargs;
 289     U8          lval;           /* XXX merge lval and hasargs? */
 290     PAD         *oldcomppad;
 291     OP *        retop;  /* op to execute on exit from sub */
 292 };
 293
 294 /* base for the next two macros. Don't use directly.
 295  * Note that the refcnt of the cv is incremented twice;  The CX one is
 296  * decremented by LEAVESUB, the other by LEAVE. */
 297
 298 #define PUSHSUB_BASE(cx)                                                \
 299         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
 300                 CopFILE((COP*)CvSTART(cv)),                             \
 301                 CopLINE((COP*)CvSTART(cv)));                            \
 302                                                                         \
 303         cx->blk_sub.cv = cv;                                            \
 304         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 305         cx->blk_sub.hasargs = hasargs;                                  \
 306         cx->blk_sub.retop = NULL;                                       \
 307         if (!CvDEPTH(cv)) {                                             \
 308             SvREFCNT_inc_simple_void_NN(cv);                            \
 309             SvREFCNT_inc_simple_void_NN(cv);                            \
 310             SAVEFREESV(cv);                                             \
 311         }
 312
 313
 314 #define PUSHSUB(cx)                                                     \
 315         PUSHSUB_BASE(cx)                                                \
 316         cx->blk_sub.lval = PL_op->op_private &                          \
 317                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 318
 319 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 320 #define PUSHSUB_DB(cx)                                                  \
 321         PUSHSUB_BASE(cx)                                                \
 322         cx->blk_sub.lval = 0;
 323
 324
 325 #define PUSHFORMAT(cx, retop)                                           \
 326         cx->blk_sub.cv = cv;                                            \
 327         cx->blk_sub.gv = gv;                                            \
 328         cx->blk_sub.retop = (retop);                                    \
 329         cx->blk_sub.hasargs = 0;                                        \
 330         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
 331         SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
 332
 333 #define POP_SAVEARRAY()                                         \
 334     STMT_START {                                                        \
 335         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 336         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 337     } STMT_END
 338
 339 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 340  * leave any (a fast av_clear(ary), basically) */
 341 #define CLEAR_ARGARRAY(ary) \
 342     STMT_START {                                                        \
 343         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 344         AvARRAY(ary) = AvALLOC(ary);                                    \
 345         AvFILLp(ary) = -1;                                              \
 346     } STMT_END
 347
 348 #define POPSUB(cx,sv)                                                   \
 349     STMT_START {                                                        \
 350         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
 351                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
 352                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
 353                                                                         \
 354         if (cx->blk_sub.hasargs) {                                      \
 355             POP_SAVEARRAY();                                            \
 356             /* abandon @_ if it got reified */                          \
 357             if (AvREAL(cx->blk_sub.argarray)) {                         \
 358                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
 359                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 360                 cx->blk_sub.argarray = newAV();                         \
 361                 av_extend(cx->blk_sub.argarray, fill);                  \
 362                 AvREIFY_only(cx->blk_sub.argarray);                     \
 363                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
 364             }                                                           \
 365             else {                                                      \
 366                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 367             }                                                           \
 368         }                                                               \
 369         sv = (SV*)cx->blk_sub.cv;                                       \
 370         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 371             sv = NULL;                                          \
 372     } STMT_END
 373
 374 #define LEAVESUB(sv)                                                    \
 375     STMT_START {                                                        \
 376         if (sv)                                                         \
 377             SvREFCNT_dec(sv);                                           \
 378     } STMT_END
 379
 380 #define POPFORMAT(cx)                                                   \
 381         setdefout(cx->blk_sub.dfoutgv);                                 \
 382         SvREFCNT_dec(cx->blk_sub.dfoutgv);
 383
 384 /* eval context */
 385 struct block_eval {
 386     U8          old_in_eval;
 387     U16         old_op_type;
 388     SV *        old_namesv;
 389     OP *        old_eval_root;
 390     SV *        cur_text;
 391     CV *        cv;
 392     OP *        retop;  /* op to execute on exit from eval */
 393     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 394 };
 395
 396 #define PUSHEVAL(cx,n,fgv)                                              \
 397     STMT_START {                                                        \
 398         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 399         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 400         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 401         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 402         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 403         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 404         cx->blk_eval.retop = NULL;                                      \
 405         cx->blk_eval.cur_top_env = PL_top_env;                          \
 406     } STMT_END
 407
 408 #define POPEVAL(cx)                                                     \
 409     STMT_START {                                                        \
 410         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 411         optype = cx->blk_eval.old_op_type;                              \
 412         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 413         if (cx->blk_eval.old_namesv)                                    \
 414             sv_2mortal(cx->blk_eval.old_namesv);                        \
 415     } STMT_END
 416
 417 /* loop context */
 418 struct block_loop {
 419     char *      label;
 420     I32         resetsp;
 421     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 422     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
 423         why next_op is conditionally defined below.)  */
 424 #ifdef USE_ITHREADS
 425     void *      iterdata;
 426     PAD         *oldcomppad;
 427 #else
 428     OP *        next_op;
 429     SV **       itervar;
 430 #endif
 431     SV *        itersave;
 432     /* (from inspection of source code) for a .. range of strings this is the
 433        current string.  */
 434     SV *        iterlval;
 435     /* (from inspection of source code) for a foreach loop this is the array
 436        being iterated over. For a .. range of numbers it's the current value.
 437        A check is often made on the SvTYPE of iterary to determine whether
 438        we are iterating over an array or a range. (numbers or strings)  */
 439     AV *        iterary;
 440     IV          iterix;
 441     /* (from inspection of source code) for a .. range of numbers this is the
 442        maximum value.  */
 443     IV          itermax;
 444 };
 445 /* It might be possible to squeeze this structure further. As best I can tell
 446    itermax and iterlval are never used at the same time, so it might be possible
 447    to make them into a union. However, I'm not confident that there are enough
 448    flag bits/NULLable pointers in this structure alone to encode which is
 449    active. There is, however, U8 of space free in struct block, which could be
 450    used. Right now it may not be worth squeezing this structure further, as it's
 451    the largest part of struct block, and currently struct block is 64 bytes on
 452    an ILP32 system, which will give good cache alignment.
 453 */
 454
 455 #ifdef USE_ITHREADS
 456 #  define CxITERVAR(c)                                                  \
 457         ((c)->blk_loop.iterdata                                         \
 458          ? (CxPADLOOP(cx)                                               \
 459             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 460                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 461             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 462          : (SV**)NULL)
 463 #  define CX_ITERDATA_SET(cx,idata)                                     \
 464         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 465         if ((cx->blk_loop.iterdata = (idata)))                          \
 466             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 467         else                                                            \
 468             cx->blk_loop.itersave = NULL;
 469 #else
 470 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 471 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 472         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 473             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 474         else                                                            \
 475             cx->blk_loop.itersave = NULL;
 476 #endif
 477 #define CxLABEL(c)      (0 + (c)->blk_loop.label)
 478
 479 #ifdef USE_ITHREADS
 480 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
 481 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
 482 #else
 483 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
 484 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
 485 #endif
 486
 487 #define PUSHLOOP(cx, dat, s)                                            \
 488         cx->blk_loop.label = PL_curcop->cop_label;                      \
 489         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 490         cx->blk_loop.my_op = cLOOP;                                     \
 491         PUSHLOOP_OP_NEXT;                                               \
 492         cx->blk_loop.iterlval = NULL;                                   \
 493         cx->blk_loop.iterary = NULL;                                    \
 494         cx->blk_loop.iterix = -1;                                       \
 495         CX_ITERDATA_SET(cx,dat);
 496
 497 #define POPLOOP(cx)                                                     \
 498         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 499         if (CxITERVAR(cx)) {                                            \
 500             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 501                 SV ** const s_v_p = CxITERVAR(cx);                      \
 502                 sv_2mortal(*s_v_p);                                     \
 503                 *s_v_p = cx->blk_loop.itersave;                         \
 504             }                                                           \
 505             else {                                                      \
 506                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 507             }                                                           \
 508         }                                                               \
 509         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 510             SvREFCNT_dec(cx->blk_loop.iterary);
 511
 512 /* given/when context */
 513 struct block_givwhen {
 514         OP *leave_op;
 515 };
 516
 517 #define PUSHGIVEN(cx)                                                   \
 518         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 519
 520 #define PUSHWHEN PUSHGIVEN
 521
 522 /* context common to subroutines, evals and loops */
 523 struct block {
 524     U16         blku_type;      /* what kind of context this is */
 525     U8          blku_gimme;     /* is this block running in list context? */
 526     U8          blku_spare;     /* Padding to match with struct subst */
 527     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 528     COP *       blku_oldcop;    /* old curcop pointer */
 529     I32         blku_oldmarksp; /* mark stack index */
 530     I32         blku_oldscopesp;        /* scope stack index */
 531     PMOP *      blku_oldpm;     /* values of pattern match vars */
 532
 533     union {
 534         struct block_sub        blku_sub;
 535         struct block_eval       blku_eval;
 536         struct block_loop       blku_loop;
 537         struct block_givwhen    blku_givwhen;
 538     } blk_u;
 539 };
 540 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 541 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 542 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 543 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 544 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 545 #define blk_gimme       cx_u.cx_blk.blku_gimme
 546 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 547 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 548 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 549 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 550
 551 /* Enter a block. */
 552 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 553         cx->cx_type             = t,                                    \
 554         cx->blk_oldsp           = sp - PL_stack_base,                   \
 555         cx->blk_oldcop          = PL_curcop,                            \
 556         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 557         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 558         cx->blk_oldpm           = PL_curpm,                             \
 559         cx->blk_gimme           = (U8)gimme;                            \
 560         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 561                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 562
 563 /* Exit a block (RETURN and LAST). */
 564 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 565         newsp            = PL_stack_base + cx->blk_oldsp,               \
 566         PL_curcop        = cx->blk_oldcop,                              \
 567         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 568         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 569         pm               = cx->blk_oldpm,                               \
 570         gimme            = cx->blk_gimme;                               \
 571         DEBUG_SCOPE("POPBLOCK");                                        \
 572         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 573                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 574
 575 /* Continue a block elsewhere (NEXT and REDO). */
 576 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 577         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 578         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 579         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 580         PL_curpm         = cx->blk_oldpm;                               \
 581         DEBUG_SCOPE("TOPBLOCK");
 582
 583 /* substitution context */
 584 struct subst {
 585     U16         sbu_type;       /* what kind of context this is */
 586     U8          sbu_once;       /* Actually both booleans, but U8 to matches */
 587     U8          sbu_rxtainted;  /* struct block */
 588     I32         sbu_iters;
 589     I32         sbu_maxiters;
 590     I32         sbu_rflags;
 591     I32         sbu_oldsave;
 592     char *      sbu_orig;
 593     SV *        sbu_dstr;
 594     SV *        sbu_targ;
 595     char *      sbu_s;
 596     char *      sbu_m;
 597     char *      sbu_strend;
 598     void *      sbu_rxres;
 599     REGEXP *    sbu_rx;
 600 };
 601 #define sb_iters        cx_u.cx_subst.sbu_iters
 602 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 603 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 604 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 605 #define sb_once         cx_u.cx_subst.sbu_once
 606 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 607 #define sb_orig         cx_u.cx_subst.sbu_orig
 608 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 609 #define sb_targ         cx_u.cx_subst.sbu_targ
 610 #define sb_s            cx_u.cx_subst.sbu_s
 611 #define sb_m            cx_u.cx_subst.sbu_m
 612 #define sb_strend       cx_u.cx_subst.sbu_strend
 613 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 614 #define sb_rx           cx_u.cx_subst.sbu_rx
 615
 616 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 617         cx->sb_iters            = iters,                                \
 618         cx->sb_maxiters         = maxiters,                             \
 619         cx->sb_rflags           = r_flags,                              \
 620         cx->sb_oldsave          = oldsave,                              \
 621         cx->sb_once             = once,                                 \
 622         cx->sb_rxtainted        = rxtainted,                            \
 623         cx->sb_orig             = orig,                                 \
 624         cx->sb_dstr             = dstr,                                 \
 625         cx->sb_targ             = targ,                                 \
 626         cx->sb_s                = s,                                    \
 627         cx->sb_m                = m,                                    \
 628         cx->sb_strend           = strend,                               \
 629         cx->sb_rxres            = NULL,                                 \
 630         cx->sb_rx               = rx,                                   \
 631         cx->cx_type             = CXt_SUBST;                            \
 632         rxres_save(&cx->sb_rxres, rx);                                  \
 633         (void)ReREFCNT_inc(rx)
 634
 635 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 636         rxres_free(&cx->sb_rxres);                                      \
 637         ReREFCNT_dec(cx->sb_rx)
 638
 639 struct context {
 640     union {
 641         struct block    cx_blk;
 642         struct subst    cx_subst;
 643     } cx_u;
 644 };
 645 #define cx_type cx_u.cx_subst.sbu_type
 646
 647 #define CXTYPEMASK      0xff
 648 #define CXt_NULL        0
 649 #define CXt_SUB         1
 650 #define CXt_EVAL        2
 651 #define CXt_LOOP        3
 652 #define CXt_SUBST       4
 653 #define CXt_BLOCK       5
 654 #define CXt_FORMAT      6
 655 #define CXt_GIVEN       7
 656 #define CXt_WHEN        8
 657
 658 /* private flags for CXt_SUB and CXt_NULL */
 659 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
 660                                            tear down context on exit). */
 661
 662 /* private flags for CXt_EVAL */
 663 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 664 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 665
 666 /* private flags for CXt_LOOP */
 667 #define CXp_FOREACH     0x00000200      /* a foreach loop */
 668 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
 669 #ifdef USE_ITHREADS
 670 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 671                                            has pad offset; if not set,
 672                                            iterdata holds GV* */
 673 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 674                          == (CXt_LOOP|CXp_PADVAR))
 675 #endif
 676
 677 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 678 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 679                          == CXp_MULTICALL)
 680 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 681                          == (CXt_EVAL|CXp_REAL))
 682 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 683                          == (CXt_EVAL|CXp_TRYBLOCK))
 684 #define CxFOREACH(c)    (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH))      \
 685                          == (CXt_LOOP|CXp_FOREACH))
 686 #define CxFOREACHDEF(c) (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH|CXp_FOR_DEF))\
 687                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 688
 689 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 690
 691 /*
 692 =head1 "Gimme" Values
 693 */
 694
 695 /*
 696 =for apidoc AmU||G_SCALAR
 697 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 698 L<perlcall>.
 699
 700 =for apidoc AmU||G_ARRAY
 701 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 702 L<perlcall>.
 703
 704 =for apidoc AmU||G_VOID
 705 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 706
 707 =for apidoc AmU||G_DISCARD
 708 Indicates that arguments returned from a callback should be discarded.  See
 709 L<perlcall>.
 710
 711 =for apidoc AmU||G_EVAL
 712
 713 Used to force a Perl C<eval> wrapper around a callback.  See
 714 L<perlcall>.
 715
 716 =for apidoc AmU||G_NOARGS
 717
 718 Indicates that no arguments are being sent to a callback.  See
 719 L<perlcall>.
 720
 721 =cut
 722 */
 723
 724 #define G_SCALAR        0
 725 #define G_ARRAY         1
 726 #define G_VOID          128     /* skip this bit when adding flags below */
 727
 728 /* extra flags for Perl_call_* routines */
 729 #define G_DISCARD       2       /* Call FREETMPS.
 730                                    Don't change this without consulting the
 731                                    hash actions codes defined in hv.h */
 732 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 733 #define G_NOARGS        8       /* Don't construct a @_ array. */
 734 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 735 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 736 #define G_METHOD       64       /* Calling method. */
 737 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 738                                    fold_constants. */
 739
 740 /* flag bits for PL_in_eval */
 741 #define EVAL_NULL       0       /* not in an eval */
 742 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 743 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 744 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 745 #define EVAL_INREQUIRE  8       /* The code is being required. */
 746
 747 /* Support for switching (stack and block) contexts.
 748  * This ensures magic doesn't invalidate local stack and cx pointers.
 749  */
 750
 751 #define PERLSI_UNKNOWN          -1
 752 #define PERLSI_UNDEF            0
 753 #define PERLSI_MAIN             1
 754 #define PERLSI_MAGIC            2
 755 #define PERLSI_SORT             3
 756 #define PERLSI_SIGNAL           4
 757 #define PERLSI_OVERLOAD         5
 758 #define PERLSI_DESTROY          6
 759 #define PERLSI_WARNHOOK         7
 760 #define PERLSI_DIEHOOK          8
 761 #define PERLSI_REQUIRE          9
 762
 763 struct stackinfo {
 764     AV *                si_stack;       /* stack for current runlevel */
 765     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 766     struct stackinfo *  si_prev;
 767     struct stackinfo *  si_next;
 768     I32                 si_cxix;        /* current context index */
 769     I32                 si_cxmax;       /* maximum allocated index */
 770     I32                 si_type;        /* type of runlevel */
 771     I32                 si_markoff;     /* offset where markstack begins for us.
 772                                          * currently used only with DEBUGGING,
 773                                          * but not #ifdef-ed for bincompat */
 774 };
 775
 776 typedef struct stackinfo PERL_SI;
 777
 778 #define cxstack         (PL_curstackinfo->si_cxstack)
 779 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 780 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 781
 782 #ifdef DEBUGGING
 783 #  define       SET_MARK_OFFSET \
 784     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 785 #else
 786 #  define       SET_MARK_OFFSET NOOP
 787 #endif
 788
 789 #define PUSHSTACKi(type) \
 790     STMT_START {                                                        \
 791         PERL_SI *next = PL_curstackinfo->si_next;                       \
 792         if (!next) {                                                    \
 793             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 794             next->si_prev = PL_curstackinfo;                            \
 795             PL_curstackinfo->si_next = next;                            \
 796         }                                                               \
 797         next->si_type = type;                                           \
 798         next->si_cxix = -1;                                             \
 799         AvFILLp(next->si_stack) = 0;                                    \
 800         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 801         PL_curstackinfo = next;                                         \
 802         SET_MARK_OFFSET;                                                \
 803     } STMT_END
 804
 805 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 806
 807 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 808  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 809 #define POPSTACK \
 810     STMT_START {                                                        \
 811         dSP;                                                            \
 812         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 813         if (!prev) {                                                    \
 814             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 815             my_exit(1);                                                 \
 816         }                                                               \
 817         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 818         /* don't free prev here, free them all at the END{} */          \
 819         PL_curstackinfo = prev;                                         \
 820     } STMT_END
 821
 822 #define POPSTACK_TO(s) \
 823     STMT_START {                                                        \
 824         while (PL_curstack != s) {                                      \
 825             dounwind(-1);                                               \
 826             POPSTACK;                                                   \
 827         }                                                               \
 828     } STMT_END
 829
 830 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 831 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 832
 833 /*
 834 =head1 Multicall Functions
 835
 836 =for apidoc Ams||dMULTICALL
 837 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 838
 839 =for apidoc Ams||PUSH_MULTICALL
 840 Opening bracket for a lightweight callback.
 841 See L<perlcall/Lightweight Callbacks>.
 842
 843 =for apidoc Ams||MULTICALL
 844 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 845
 846 =for apidoc Ams||POP_MULTICALL
 847 Closing bracket for a lightweight callback.
 848 See L<perlcall/Lightweight Callbacks>.
 849
 850 =cut
 851 */
 852
 853 #define dMULTICALL \
 854     SV **newsp;                 /* set by POPBLOCK */                   \
 855     PERL_CONTEXT *cx;                                                   \
 856     CV *multicall_cv;                                                   \
 857     OP *multicall_cop;                                                  \
 858     bool multicall_oldcatch;                                            \
 859     U8 hasargs = 0              /* used by PUSHSUB */
 860
 861 #define PUSH_MULTICALL(the_cv) \
 862     STMT_START {                                                        \
 863         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 864         CV * const cv = _nOnclAshIngNamE_;                              \
 865         AV * const padlist = CvPADLIST(cv);                             \
 866         ENTER;                                                          \
 867         multicall_oldcatch = CATCH_GET;                                 \
 868         SAVETMPS; SAVEVPTR(PL_op);                                      \
 869         CATCH_SET(TRUE);                                                \
 870         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 871         PUSHSUB(cx);                                                    \
 872         if (++CvDEPTH(cv) >= 2) {                                       \
 873             PERL_STACK_OVERFLOW_CHECK();                                \
 874             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 875         }                                                               \
 876         SAVECOMPPAD();                                                  \
 877         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 878         multicall_cv = cv;                                              \
 879         multicall_cop = CvSTART(cv);                                    \
 880     } STMT_END
 881
 882 #define MULTICALL \
 883     STMT_START {                                                        \
 884         PL_op = multicall_cop;                                          \
 885         CALLRUNOPS(aTHX);                                               \
 886     } STMT_END
 887
 888 #define POP_MULTICALL \
 889     STMT_START {                                                        \
 890         LEAVESUB(multicall_cv);                                         \
 891         CvDEPTH(multicall_cv)--;                                        \
 892         POPBLOCK(cx,PL_curpm);                                          \
 893         CATCH_SET(multicall_oldcatch);                                  \
 894         LEAVE;                                                          \
 895     } STMT_END
 896
 897 /*
 898  * Local variables:
 899  * c-indentation-style: bsd
 900  * c-basic-offset: 4
 901  * indent-tabs-mode: t
 902  * End:
 903  *
 904  * ex: set ts=8 sts=4 sw=4 noet:
 905  */