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