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     OP *        retop;  /* op to execute on exit from sub */
 283     /* Above here is the same for sub, format and eval.  */
 284     CV *        cv;
 285     /* Above here is the same for sub and format.  */
 286     AV *        savearray;
 287     AV *        argarray;
 288     I32         olddepth;
 289     PAD         *oldcomppad;
 290 };
 291
 292
 293 /* format context */
 294 struct block_format {
 295     OP *        retop;  /* op to execute on exit from sub */
 296     /* Above here is the same for sub, format and eval.  */
 297     CV *        cv;
 298     /* Above here is the same for sub and format.  */
 299     GV *        gv;
 300     GV *        dfoutgv;
 301 };
 302
 303 /* base for the next two macros. Don't use directly.
 304  * Note that the refcnt of the cv is incremented twice;  The CX one is
 305  * decremented by LEAVESUB, the other by LEAVE. */
 306
 307 #define PUSHSUB_BASE(cx)                                                \
 308         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
 309                 CopFILE((COP*)CvSTART(cv)),                             \
 310                 CopLINE((COP*)CvSTART(cv)));                            \
 311                                                                         \
 312         cx->blk_sub.cv = cv;                                            \
 313         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 314         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
 315         cx->blk_sub.retop = NULL;                                       \
 316         if (!CvDEPTH(cv)) {                                             \
 317             SvREFCNT_inc_simple_void_NN(cv);                            \
 318             SvREFCNT_inc_simple_void_NN(cv);                            \
 319             SAVEFREESV(cv);                                             \
 320         }
 321
 322
 323 #define PUSHSUB(cx)                                                     \
 324         PUSHSUB_BASE(cx)                                                \
 325         cx->blk_u16 = PL_op->op_private &                               \
 326                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 327
 328 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 329 #define PUSHSUB_DB(cx)                                                  \
 330         PUSHSUB_BASE(cx)                                                \
 331         cx->blk_u16 = 0;
 332
 333
 334 #define PUSHFORMAT(cx, retop)                                           \
 335         cx->blk_format.cv = cv;                                         \
 336         cx->blk_format.gv = gv;                                         \
 337         cx->blk_format.retop = (retop);                                 \
 338         cx->blk_format.dfoutgv = PL_defoutgv;                           \
 339         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
 340
 341 #define POP_SAVEARRAY()                                         \
 342     STMT_START {                                                        \
 343         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 344         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 345     } STMT_END
 346
 347 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 348  * leave any (a fast av_clear(ary), basically) */
 349 #define CLEAR_ARGARRAY(ary) \
 350     STMT_START {                                                        \
 351         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 352         AvARRAY(ary) = AvALLOC(ary);                                    \
 353         AvFILLp(ary) = -1;                                              \
 354     } STMT_END
 355
 356 #define POPSUB(cx,sv)                                                   \
 357     STMT_START {                                                        \
 358         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
 359                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
 360                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
 361                                                                         \
 362         if (CxHASARGS(cx)) {                                            \
 363             POP_SAVEARRAY();                                            \
 364             /* abandon @_ if it got reified */                          \
 365             if (AvREAL(cx->blk_sub.argarray)) {                         \
 366                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
 367                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 368                 cx->blk_sub.argarray = newAV();                         \
 369                 av_extend(cx->blk_sub.argarray, fill);                  \
 370                 AvREIFY_only(cx->blk_sub.argarray);                     \
 371                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
 372             }                                                           \
 373             else {                                                      \
 374                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 375             }                                                           \
 376         }                                                               \
 377         sv = (SV*)cx->blk_sub.cv;                                       \
 378         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 379             sv = NULL;                                          \
 380     } STMT_END
 381
 382 #define LEAVESUB(sv)                                                    \
 383     STMT_START {                                                        \
 384         if (sv)                                                         \
 385             SvREFCNT_dec(sv);                                           \
 386     } STMT_END
 387
 388 #define POPFORMAT(cx)                                                   \
 389         setdefout(cx->blk_format.dfoutgv);                              \
 390         SvREFCNT_dec(cx->blk_format.dfoutgv);
 391
 392 /* eval context */
 393 struct block_eval {
 394     OP *        retop;  /* op to execute on exit from eval */
 395     /* Above here is the same for sub, format and eval.  */
 396     U8          old_in_eval;
 397     U16         old_op_type;
 398     SV *        old_namesv;
 399     OP *        old_eval_root;
 400     SV *        cur_text;
 401     CV *        cv;
 402     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 403 };
 404
 405 #define CxOLD_IN_EVAL(cx)       (0 + (cx)->blk_eval.old_in_eval)
 406 #define CxOLD_OP_TYPE(cx)       (0 + (cx)->blk_eval.old_op_type)
 407
 408 #define PUSHEVAL(cx,n,fgv)                                              \
 409     STMT_START {                                                        \
 410         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 411         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 412         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 413         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 414         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 415         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 416         cx->blk_eval.retop = NULL;                                      \
 417         cx->blk_eval.cur_top_env = PL_top_env;                          \
 418     } STMT_END
 419
 420 #define POPEVAL(cx)                                                     \
 421     STMT_START {                                                        \
 422         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 423         optype = CxOLD_OP_TYPE(cx);                                     \
 424         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 425         if (cx->blk_eval.old_namesv)                                    \
 426             sv_2mortal(cx->blk_eval.old_namesv);                        \
 427     } STMT_END
 428
 429 /* loop context */
 430 struct block_loop {
 431     I32         resetsp;
 432     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 433     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
 434         why next_op is conditionally defined below.)  */
 435 #ifdef USE_ITHREADS
 436     void *      iterdata;
 437     PAD         *oldcomppad;
 438 #else
 439     OP *        next_op;
 440     SV **       itervar;
 441 #endif
 442     SV *        itersave;
 443     /* (from inspection of source code) for a .. range of strings this is the
 444        current string.  */
 445     SV *        iterlval;
 446     /* (from inspection of source code) for a foreach loop this is the array
 447        being iterated over. For a .. range of numbers it's the current value.
 448        A check is often made on the SvTYPE of iterary to determine whether
 449        we are iterating over an array or a range. (numbers or strings)  */
 450     AV *        iterary;
 451     IV          iterix;
 452     /* (from inspection of source code) for a .. range of numbers this is the
 453        maximum value.  */
 454     IV          itermax;
 455 };
 456 /* It might be possible to squeeze this structure further. As best I can tell
 457    itermax and iterlval are never used at the same time, so it might be possible
 458    to make them into a union. However, I'm not confident that there are enough
 459    flag bits/NULLable pointers in this structure alone to encode which is
 460    active. There is, however, U8 of space free in struct block, which could be
 461    used. Right now it may not be worth squeezing this structure further, as it's
 462    the largest part of struct block, and currently struct block is 64 bytes on
 463    an ILP32 system, which will give good cache alignment.
 464 */
 465
 466 #ifdef USE_ITHREADS
 467 #  define CxITERVAR(c)                                                  \
 468         ((c)->blk_loop.iterdata                                         \
 469          ? (CxPADLOOP(cx)                                               \
 470             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 471                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 472             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 473          : (SV**)NULL)
 474 #  define CX_ITERDATA_SET(cx,idata)                                     \
 475         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 476         if ((cx->blk_loop.iterdata = (idata)))                          \
 477             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 478         else                                                            \
 479             cx->blk_loop.itersave = NULL;
 480 #else
 481 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 482 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 483         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 484             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 485         else                                                            \
 486             cx->blk_loop.itersave = NULL;
 487 #endif
 488 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
 489 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 490 #define CxLVAL(c)       (0 + (c)->blk_u16)
 491
 492 #ifdef USE_ITHREADS
 493 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
 494 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
 495 #else
 496 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
 497 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
 498 #endif
 499
 500 #define PUSHLOOP(cx, dat, s)                                            \
 501         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 502         cx->blk_loop.my_op = cLOOP;                                     \
 503         PUSHLOOP_OP_NEXT;                                               \
 504         cx->blk_loop.iterlval = NULL;                                   \
 505         cx->blk_loop.iterary = NULL;                                    \
 506         cx->blk_loop.iterix = -1;                                       \
 507         CX_ITERDATA_SET(cx,dat);
 508
 509 #define POPLOOP(cx)                                                     \
 510         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 511         if (CxITERVAR(cx)) {                                            \
 512             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 513                 SV ** const s_v_p = CxITERVAR(cx);                      \
 514                 sv_2mortal(*s_v_p);                                     \
 515                 *s_v_p = cx->blk_loop.itersave;                         \
 516             }                                                           \
 517             else {                                                      \
 518                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 519             }                                                           \
 520         }                                                               \
 521         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 522             SvREFCNT_dec(cx->blk_loop.iterary);
 523
 524 /* given/when context */
 525 struct block_givwhen {
 526         OP *leave_op;
 527 };
 528
 529 #define PUSHGIVEN(cx)                                                   \
 530         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 531
 532 #define PUSHWHEN PUSHGIVEN
 533
 534 /* context common to subroutines, evals and loops */
 535 struct block {
 536     U8          blku_type;      /* what kind of context this is */
 537     U8          blku_gimme;     /* is this block running in list context? */
 538     U16         blku_u16;       /* U16 of space used by block_sub */
 539     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 540     COP *       blku_oldcop;    /* old curcop pointer */
 541     I32         blku_oldmarksp; /* mark stack index */
 542     I32         blku_oldscopesp;        /* scope stack index */
 543     PMOP *      blku_oldpm;     /* values of pattern match vars */
 544
 545     union {
 546         struct block_sub        blku_sub;
 547         struct block_format     blku_format;
 548         struct block_eval       blku_eval;
 549         struct block_loop       blku_loop;
 550         struct block_givwhen    blku_givwhen;
 551     } blk_u;
 552 };
 553 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 554 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 555 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 556 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 557 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 558 #define blk_gimme       cx_u.cx_blk.blku_gimme
 559 #define blk_u16         cx_u.cx_blk.blku_u16
 560 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 561 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 562 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 563 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 564 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 565
 566 /* Enter a block. */
 567 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 568         cx->cx_type             = t,                                    \
 569         cx->blk_oldsp           = sp - PL_stack_base,                   \
 570         cx->blk_oldcop          = PL_curcop,                            \
 571         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 572         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 573         cx->blk_oldpm           = PL_curpm,                             \
 574         cx->blk_gimme           = (U8)gimme;                            \
 575         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 576                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 577
 578 /* Exit a block (RETURN and LAST). */
 579 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 580         newsp            = PL_stack_base + cx->blk_oldsp,               \
 581         PL_curcop        = cx->blk_oldcop,                              \
 582         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 583         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 584         pm               = cx->blk_oldpm,                               \
 585         gimme            = cx->blk_gimme;                               \
 586         DEBUG_SCOPE("POPBLOCK");                                        \
 587         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 588                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 589
 590 /* Continue a block elsewhere (NEXT and REDO). */
 591 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 592         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 593         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 594         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 595         PL_curpm         = cx->blk_oldpm;                               \
 596         DEBUG_SCOPE("TOPBLOCK");
 597
 598 /* substitution context */
 599 struct subst {
 600     U8          sbu_type;       /* what kind of context this is */
 601     U8          sbu_once;       /* Actually both booleans, but U8/U16 */
 602     U16         sbu_rxtainted;  /* matches struct block */
 603     I32         sbu_iters;
 604     I32         sbu_maxiters;
 605     I32         sbu_rflags;
 606     I32         sbu_oldsave;
 607     char *      sbu_orig;
 608     SV *        sbu_dstr;
 609     SV *        sbu_targ;
 610     char *      sbu_s;
 611     char *      sbu_m;
 612     char *      sbu_strend;
 613     void *      sbu_rxres;
 614     REGEXP *    sbu_rx;
 615 };
 616 #define sb_iters        cx_u.cx_subst.sbu_iters
 617 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 618 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 619 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 620 #define sb_once         cx_u.cx_subst.sbu_once
 621 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 622 #define sb_orig         cx_u.cx_subst.sbu_orig
 623 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 624 #define sb_targ         cx_u.cx_subst.sbu_targ
 625 #define sb_s            cx_u.cx_subst.sbu_s
 626 #define sb_m            cx_u.cx_subst.sbu_m
 627 #define sb_strend       cx_u.cx_subst.sbu_strend
 628 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 629 #define sb_rx           cx_u.cx_subst.sbu_rx
 630
 631 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 632         cx->sb_iters            = iters,                                \
 633         cx->sb_maxiters         = maxiters,                             \
 634         cx->sb_rflags           = r_flags,                              \
 635         cx->sb_oldsave          = oldsave,                              \
 636         cx->sb_once             = once,                                 \
 637         cx->sb_rxtainted        = rxtainted,                            \
 638         cx->sb_orig             = orig,                                 \
 639         cx->sb_dstr             = dstr,                                 \
 640         cx->sb_targ             = targ,                                 \
 641         cx->sb_s                = s,                                    \
 642         cx->sb_m                = m,                                    \
 643         cx->sb_strend           = strend,                               \
 644         cx->sb_rxres            = NULL,                                 \
 645         cx->sb_rx               = rx,                                   \
 646         cx->cx_type             = CXt_SUBST;                            \
 647         rxres_save(&cx->sb_rxres, rx);                                  \
 648         (void)ReREFCNT_inc(rx)
 649
 650 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 651         rxres_free(&cx->sb_rxres);                                      \
 652         ReREFCNT_dec(cx->sb_rx)
 653
 654 struct context {
 655     union {
 656         struct block    cx_blk;
 657         struct subst    cx_subst;
 658     } cx_u;
 659 };
 660 #define cx_type cx_u.cx_subst.sbu_type
 661
 662 #define CXTYPEMASK      0xf
 663 #define CXt_NULL        0
 664 #define CXt_SUB         1
 665 #define CXt_EVAL        2
 666 #define CXt_LOOP        3
 667 #define CXt_SUBST       4
 668 #define CXt_BLOCK       5
 669 #define CXt_FORMAT      6
 670 #define CXt_GIVEN       7
 671 #define CXt_WHEN        8
 672
 673 /* private flags for CXt_SUB and CXt_NULL
 674    However, this is checked in many places which do not check the type, so
 675    this bit needs to be kept clear for most everything else. For reasons I
 676    haven't investigated, it can coexist with CXp_FOR_DEF */
 677 #define CXp_MULTICALL   0x0000040       /* part of a multicall (so don't
 678                                            tear down context on exit). */
 679
 680 /* private flags for CXt_SUB and CXt_FORMAT */
 681 #define CXp_HASARGS     0x00000020
 682
 683 /* private flags for CXt_EVAL */
 684 #define CXp_REAL        0x00000010      /* truly eval'', not a lookalike */
 685 #define CXp_TRYBLOCK    0x00000020      /* eval{}, not eval'' or similar */
 686
 687 /* private flags for CXt_LOOP */
 688 #define CXp_FOREACH     0x00000020      /* a foreach loop */
 689 #define CXp_FOR_DEF     0x00000040      /* foreach using $_ */
 690 #ifdef USE_ITHREADS
 691 #  define CXp_PADVAR    0x00000010      /* itervar lives on pad, iterdata
 692                                            has pad offset; if not set,
 693                                            iterdata holds GV* */
 694 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 695                          == (CXt_LOOP|CXp_PADVAR))
 696 #endif
 697
 698 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 699 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 700                          == CXp_MULTICALL)
 701 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 702                          == (CXt_EVAL|CXp_REAL))
 703 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 704                          == (CXt_EVAL|CXp_TRYBLOCK))
 705 #define CxFOREACH(c)    (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH))      \
 706                          == (CXt_LOOP|CXp_FOREACH))
 707 #define CxFOREACHDEF(c) (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH|CXp_FOR_DEF))\
 708                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 709
 710 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 711
 712 /*
 713 =head1 "Gimme" Values
 714 */
 715
 716 /*
 717 =for apidoc AmU||G_SCALAR
 718 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 719 L<perlcall>.
 720
 721 =for apidoc AmU||G_ARRAY
 722 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 723 L<perlcall>.
 724
 725 =for apidoc AmU||G_VOID
 726 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 727
 728 =for apidoc AmU||G_DISCARD
 729 Indicates that arguments returned from a callback should be discarded.  See
 730 L<perlcall>.
 731
 732 =for apidoc AmU||G_EVAL
 733
 734 Used to force a Perl C<eval> wrapper around a callback.  See
 735 L<perlcall>.
 736
 737 =for apidoc AmU||G_NOARGS
 738
 739 Indicates that no arguments are being sent to a callback.  See
 740 L<perlcall>.
 741
 742 =cut
 743 */
 744
 745 #define G_SCALAR        2
 746 #define G_ARRAY         3
 747 #define G_VOID          1
 748 #define G_WANT          3
 749
 750 /* extra flags for Perl_call_* routines */
 751 #define G_DISCARD       4       /* Call FREETMPS.
 752                                    Don't change this without consulting the
 753                                    hash actions codes defined in hv.h */
 754 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
 755 #define G_NOARGS       16       /* Don't construct a @_ array. */
 756 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
 757 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
 758 #define G_METHOD      128       /* Calling method. */
 759 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 760                                    fold_constants. */
 761
 762 /* flag bits for PL_in_eval */
 763 #define EVAL_NULL       0       /* not in an eval */
 764 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 765 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 766 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 767 #define EVAL_INREQUIRE  8       /* The code is being required. */
 768
 769 /* Support for switching (stack and block) contexts.
 770  * This ensures magic doesn't invalidate local stack and cx pointers.
 771  */
 772
 773 #define PERLSI_UNKNOWN          -1
 774 #define PERLSI_UNDEF            0
 775 #define PERLSI_MAIN             1
 776 #define PERLSI_MAGIC            2
 777 #define PERLSI_SORT             3
 778 #define PERLSI_SIGNAL           4
 779 #define PERLSI_OVERLOAD         5
 780 #define PERLSI_DESTROY          6
 781 #define PERLSI_WARNHOOK         7
 782 #define PERLSI_DIEHOOK          8
 783 #define PERLSI_REQUIRE          9
 784
 785 struct stackinfo {
 786     AV *                si_stack;       /* stack for current runlevel */
 787     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 788     struct stackinfo *  si_prev;
 789     struct stackinfo *  si_next;
 790     I32                 si_cxix;        /* current context index */
 791     I32                 si_cxmax;       /* maximum allocated index */
 792     I32                 si_type;        /* type of runlevel */
 793     I32                 si_markoff;     /* offset where markstack begins for us.
 794                                          * currently used only with DEBUGGING,
 795                                          * but not #ifdef-ed for bincompat */
 796 };
 797
 798 typedef struct stackinfo PERL_SI;
 799
 800 #define cxstack         (PL_curstackinfo->si_cxstack)
 801 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 802 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 803
 804 #ifdef DEBUGGING
 805 #  define       SET_MARK_OFFSET \
 806     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 807 #else
 808 #  define       SET_MARK_OFFSET NOOP
 809 #endif
 810
 811 #define PUSHSTACKi(type) \
 812     STMT_START {                                                        \
 813         PERL_SI *next = PL_curstackinfo->si_next;                       \
 814         if (!next) {                                                    \
 815             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 816             next->si_prev = PL_curstackinfo;                            \
 817             PL_curstackinfo->si_next = next;                            \
 818         }                                                               \
 819         next->si_type = type;                                           \
 820         next->si_cxix = -1;                                             \
 821         AvFILLp(next->si_stack) = 0;                                    \
 822         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 823         PL_curstackinfo = next;                                         \
 824         SET_MARK_OFFSET;                                                \
 825     } STMT_END
 826
 827 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 828
 829 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 830  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 831 #define POPSTACK \
 832     STMT_START {                                                        \
 833         dSP;                                                            \
 834         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 835         if (!prev) {                                                    \
 836             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 837             my_exit(1);                                                 \
 838         }                                                               \
 839         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 840         /* don't free prev here, free them all at the END{} */          \
 841         PL_curstackinfo = prev;                                         \
 842     } STMT_END
 843
 844 #define POPSTACK_TO(s) \
 845     STMT_START {                                                        \
 846         while (PL_curstack != s) {                                      \
 847             dounwind(-1);                                               \
 848             POPSTACK;                                                   \
 849         }                                                               \
 850     } STMT_END
 851
 852 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 853 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 854
 855 /*
 856 =head1 Multicall Functions
 857
 858 =for apidoc Ams||dMULTICALL
 859 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 860
 861 =for apidoc Ams||PUSH_MULTICALL
 862 Opening bracket for a lightweight callback.
 863 See L<perlcall/Lightweight Callbacks>.
 864
 865 =for apidoc Ams||MULTICALL
 866 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 867
 868 =for apidoc Ams||POP_MULTICALL
 869 Closing bracket for a lightweight callback.
 870 See L<perlcall/Lightweight Callbacks>.
 871
 872 =cut
 873 */
 874
 875 #define dMULTICALL \
 876     SV **newsp;                 /* set by POPBLOCK */                   \
 877     PERL_CONTEXT *cx;                                                   \
 878     CV *multicall_cv;                                                   \
 879     OP *multicall_cop;                                                  \
 880     bool multicall_oldcatch;                                            \
 881     U8 hasargs = 0              /* used by PUSHSUB */
 882
 883 #define PUSH_MULTICALL(the_cv) \
 884     STMT_START {                                                        \
 885         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 886         CV * const cv = _nOnclAshIngNamE_;                              \
 887         AV * const padlist = CvPADLIST(cv);                             \
 888         ENTER;                                                          \
 889         multicall_oldcatch = CATCH_GET;                                 \
 890         SAVETMPS; SAVEVPTR(PL_op);                                      \
 891         CATCH_SET(TRUE);                                                \
 892         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 893         PUSHSUB(cx);                                                    \
 894         if (++CvDEPTH(cv) >= 2) {                                       \
 895             PERL_STACK_OVERFLOW_CHECK();                                \
 896             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 897         }                                                               \
 898         SAVECOMPPAD();                                                  \
 899         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 900         multicall_cv = cv;                                              \
 901         multicall_cop = CvSTART(cv);                                    \
 902     } STMT_END
 903
 904 #define MULTICALL \
 905     STMT_START {                                                        \
 906         PL_op = multicall_cop;                                          \
 907         CALLRUNOPS(aTHX);                                               \
 908     } STMT_END
 909
 910 #define POP_MULTICALL \
 911     STMT_START {                                                        \
 912         LEAVESUB(multicall_cv);                                         \
 913         CvDEPTH(multicall_cv)--;                                        \
 914         POPBLOCK(cx,PL_curpm);                                          \
 915         CATCH_SET(multicall_oldcatch);                                  \
 916         LEAVE;                                                          \
 917     } STMT_END
 918
 919 /*
 920  * Local variables:
 921  * c-indentation-style: bsd
 922  * c-basic-offset: 4
 923  * indent-tabs-mode: t
 924  * End:
 925  *
 926  * ex: set ts=8 sts=4 sw=4 noet:
 927  */