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     SV *        old_namesv;
 397     OP *        old_eval_root;
 398     SV *        cur_text;
 399     CV *        cv;
 400     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 401 };
 402
 403 /* If we ever need more than 512 op types, change the shift from 7.
 404    blku_gimme is actually also only 2 bits, so could be merged with something.
 405 */
 406
 407 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
 408 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
 409
 410 #define PUSHEVAL(cx,n,fgv)                                              \
 411     STMT_START {                                                        \
 412         assert(!(PL_in_eval & ~0x7F));                                  \
 413         assert(!(PL_op->op_type & ~0x1FF));                             \
 414         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
 415         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 416         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 417         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 418         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 419         cx->blk_eval.retop = NULL;                                      \
 420         cx->blk_eval.cur_top_env = PL_top_env;                          \
 421     } STMT_END
 422
 423 #define POPEVAL(cx)                                                     \
 424     STMT_START {                                                        \
 425         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 426         optype = CxOLD_OP_TYPE(cx);                                     \
 427         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 428         if (cx->blk_eval.old_namesv)                                    \
 429             sv_2mortal(cx->blk_eval.old_namesv);                        \
 430     } STMT_END
 431
 432 /* loop context */
 433 struct block_loop {
 434     I32         resetsp;
 435     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 436     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
 437         why next_op is conditionally defined below.)  */
 438 #ifdef USE_ITHREADS
 439     void *      iterdata;
 440     PAD         *oldcomppad;
 441 #else
 442     OP *        next_op;
 443     SV **       itervar;
 444 #endif
 445     SV *        itersave;
 446     union {
 447         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
 448             AV * ary; /* use the stack if this is NULL */
 449             IV ix;
 450         } ary;
 451         struct { /* valid if type is LOOP_LAZYIV */
 452             IV cur;
 453             IV end;
 454         } lazyiv;
 455         struct { /* valid if type if LOOP_LAZYSV */
 456             SV * cur;
 457             SV * end; /* maxiumum value (or minimum in reverse) */
 458         } lazysv;
 459     } state_u;
 460 };
 461
 462 #ifdef USE_ITHREADS
 463 #  define CxITERVAR(c)                                                  \
 464         ((c)->blk_loop.iterdata                                         \
 465          ? (CxPADLOOP(cx)                                               \
 466             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 467                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 468             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 469          : (SV**)NULL)
 470 #  define CX_ITERDATA_SET(cx,idata)                                     \
 471         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 472         if ((cx->blk_loop.iterdata = (idata)))                          \
 473             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 474         else                                                            \
 475             cx->blk_loop.itersave = NULL;
 476 #else
 477 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 478 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 479         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 480             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 481         else                                                            \
 482             cx->blk_loop.itersave = NULL;
 483 #endif
 484 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
 485 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 486 #define CxLVAL(c)       (0 + (c)->blk_u16)
 487
 488 #ifdef USE_ITHREADS
 489 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
 490 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
 491 #else
 492 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
 493 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
 494 #endif
 495
 496 #define PUSHLOOP_PLAIN(cx, s)                                           \
 497         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 498         cx->blk_loop.my_op = cLOOP;                                     \
 499         PUSHLOOP_OP_NEXT;                                               \
 500         cx->blk_loop.state_u.ary.ary = NULL;                            \
 501         cx->blk_loop.state_u.ary.ix = 0;                                \
 502         CX_ITERDATA_SET(cx,NULL);
 503
 504 #define PUSHLOOP_FOR(cx, dat, s)                                        \
 505         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 506         cx->blk_loop.my_op = cLOOP;                                     \
 507         PUSHLOOP_OP_NEXT;                                               \
 508         cx->blk_loop.state_u.ary.ary = NULL;                            \
 509         cx->blk_loop.state_u.ary.ix = 0;                                \
 510         CX_ITERDATA_SET(cx,dat);
 511
 512 #define POPLOOP(cx)                                                     \
 513         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
 514             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
 515             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
 516         }                                                               \
 517         if (CxITERVAR(cx)) {                                            \
 518             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 519                 SV ** const s_v_p = CxITERVAR(cx);                      \
 520                 sv_2mortal(*s_v_p);                                     \
 521                 *s_v_p = cx->blk_loop.itersave;                         \
 522             }                                                           \
 523             else {                                                      \
 524                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 525             }                                                           \
 526         }                                                               \
 527         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
 528             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
 529
 530 /* given/when context */
 531 struct block_givwhen {
 532         OP *leave_op;
 533 };
 534
 535 #define PUSHGIVEN(cx)                                                   \
 536         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 537
 538 #define PUSHWHEN PUSHGIVEN
 539
 540 /* context common to subroutines, evals and loops */
 541 struct block {
 542     U8          blku_type;      /* what kind of context this is */
 543     U8          blku_gimme;     /* is this block running in list context? */
 544     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 545     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 546     COP *       blku_oldcop;    /* old curcop pointer */
 547     I32         blku_oldmarksp; /* mark stack index */
 548     I32         blku_oldscopesp;        /* scope stack index */
 549     PMOP *      blku_oldpm;     /* values of pattern match vars */
 550
 551     union {
 552         struct block_sub        blku_sub;
 553         struct block_format     blku_format;
 554         struct block_eval       blku_eval;
 555         struct block_loop       blku_loop;
 556         struct block_givwhen    blku_givwhen;
 557     } blk_u;
 558 };
 559 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 560 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 561 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 562 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 563 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 564 #define blk_gimme       cx_u.cx_blk.blku_gimme
 565 #define blk_u16         cx_u.cx_blk.blku_u16
 566 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 567 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 568 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 569 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 570 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 571
 572 /* Enter a block. */
 573 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 574         cx->cx_type             = t,                                    \
 575         cx->blk_oldsp           = sp - PL_stack_base,                   \
 576         cx->blk_oldcop          = PL_curcop,                            \
 577         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 578         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 579         cx->blk_oldpm           = PL_curpm,                             \
 580         cx->blk_gimme           = (U8)gimme;                            \
 581         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 582                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 583
 584 /* Exit a block (RETURN and LAST). */
 585 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 586         newsp            = PL_stack_base + cx->blk_oldsp,               \
 587         PL_curcop        = cx->blk_oldcop,                              \
 588         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 589         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 590         pm               = cx->blk_oldpm,                               \
 591         gimme            = cx->blk_gimme;                               \
 592         DEBUG_SCOPE("POPBLOCK");                                        \
 593         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 594                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 595
 596 /* Continue a block elsewhere (NEXT and REDO). */
 597 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 598         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 599         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 600         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 601         PL_curpm         = cx->blk_oldpm;                               \
 602         DEBUG_SCOPE("TOPBLOCK");
 603
 604 /* substitution context */
 605 struct subst {
 606     U8          sbu_type;       /* what kind of context this is */
 607     U8          sbu_rflags;
 608     U16         sbu_rxtainted;  /* matches struct block */
 609     I32         sbu_iters;
 610     I32         sbu_maxiters;
 611     I32         sbu_oldsave;
 612     char *      sbu_orig;
 613     SV *        sbu_dstr;
 614     SV *        sbu_targ;
 615     char *      sbu_s;
 616     char *      sbu_m;
 617     char *      sbu_strend;
 618     void *      sbu_rxres;
 619     REGEXP *    sbu_rx;
 620 };
 621 #define sb_iters        cx_u.cx_subst.sbu_iters
 622 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 623 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 624 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 625 #define sb_once         cx_u.cx_subst.sbu_once
 626 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 627 #define sb_orig         cx_u.cx_subst.sbu_orig
 628 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 629 #define sb_targ         cx_u.cx_subst.sbu_targ
 630 #define sb_s            cx_u.cx_subst.sbu_s
 631 #define sb_m            cx_u.cx_subst.sbu_m
 632 #define sb_strend       cx_u.cx_subst.sbu_strend
 633 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 634 #define sb_rx           cx_u.cx_subst.sbu_rx
 635
 636 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 637         cx->sb_iters            = iters,                                \
 638         cx->sb_maxiters         = maxiters,                             \
 639         cx->sb_rflags           = r_flags,                              \
 640         cx->sb_oldsave          = oldsave,                              \
 641         cx->sb_rxtainted        = rxtainted,                            \
 642         cx->sb_orig             = orig,                                 \
 643         cx->sb_dstr             = dstr,                                 \
 644         cx->sb_targ             = targ,                                 \
 645         cx->sb_s                = s,                                    \
 646         cx->sb_m                = m,                                    \
 647         cx->sb_strend           = strend,                               \
 648         cx->sb_rxres            = NULL,                                 \
 649         cx->sb_rx               = rx,                                   \
 650         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
 651         rxres_save(&cx->sb_rxres, rx);                                  \
 652         (void)ReREFCNT_inc(rx)
 653
 654 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
 655
 656 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 657         rxres_free(&cx->sb_rxres);                                      \
 658         ReREFCNT_dec(cx->sb_rx)
 659
 660 struct context {
 661     union {
 662         struct block    cx_blk;
 663         struct subst    cx_subst;
 664     } cx_u;
 665 };
 666 #define cx_type cx_u.cx_subst.sbu_type
 667
 668 #define CXTYPEMASK      0xf
 669 #define CXt_NULL        0
 670 #define CXt_SUB         1
 671 #define CXt_EVAL        2
 672 #define CXt_WHEN        3
 673 #define CXt_SUBST       4
 674 #define CXt_BLOCK       5
 675 #define CXt_FORMAT      6
 676 #define CXt_GIVEN       7
 677 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
 678 #define CXt_LOOP_FOR    8
 679 #define CXt_LOOP_PLAIN  9
 680 #define CXt_LOOP_LAZYSV 10
 681 #define CXt_LOOP_LAZYIV 11
 682
 683 /* private flags for CXt_SUB and CXt_NULL
 684    However, this is checked in many places which do not check the type, so
 685    this bit needs to be kept clear for most everything else. For reasons I
 686    haven't investigated, it can coexist with CXp_FOR_DEF */
 687 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
 688                                    tear down context on exit). */
 689
 690 /* private flags for CXt_SUB and CXt_FORMAT */
 691 #define CXp_HASARGS     0x20
 692
 693 /* private flags for CXt_EVAL */
 694 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
 695 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
 696
 697 /* private flags for CXt_LOOP */
 698 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
 699 #ifdef USE_ITHREADS
 700 #  define CXp_PADVAR    0x20    /* itervar lives on pad, iterdata has pad
 701                                    offset; if not set, iterdata holds GV* */
 702 #  define CxPADLOOP(c)  (CxTYPE_is_LOOP(c) && ((c)->cx_type & (CXp_PADVAR)))
 703 #endif
 704 /* private flags for CXt_SUBST */
 705 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
 706
 707 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 708 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x8)
 709 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 710                          == CXp_MULTICALL)
 711 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 712                          == (CXt_EVAL|CXp_REAL))
 713 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 714                          == (CXt_EVAL|CXp_TRYBLOCK))
 715 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
 716 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
 717                          && ((c)->cx_type & CXp_FOR_DEF))
 718
 719 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 720
 721 /*
 722 =head1 "Gimme" Values
 723 */
 724
 725 /*
 726 =for apidoc AmU||G_SCALAR
 727 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 728 L<perlcall>.
 729
 730 =for apidoc AmU||G_ARRAY
 731 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 732 L<perlcall>.
 733
 734 =for apidoc AmU||G_VOID
 735 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 736
 737 =for apidoc AmU||G_DISCARD
 738 Indicates that arguments returned from a callback should be discarded.  See
 739 L<perlcall>.
 740
 741 =for apidoc AmU||G_EVAL
 742
 743 Used to force a Perl C<eval> wrapper around a callback.  See
 744 L<perlcall>.
 745
 746 =for apidoc AmU||G_NOARGS
 747
 748 Indicates that no arguments are being sent to a callback.  See
 749 L<perlcall>.
 750
 751 =cut
 752 */
 753
 754 #define G_SCALAR        2
 755 #define G_ARRAY         3
 756 #define G_VOID          1
 757 #define G_WANT          3
 758
 759 /* extra flags for Perl_call_* routines */
 760 #define G_DISCARD       4       /* Call FREETMPS.
 761                                    Don't change this without consulting the
 762                                    hash actions codes defined in hv.h */
 763 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
 764 #define G_NOARGS       16       /* Don't construct a @_ array. */
 765 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
 766 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
 767 #define G_METHOD      128       /* Calling method. */
 768 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 769                                    fold_constants. */
 770
 771 /* flag bits for PL_in_eval */
 772 #define EVAL_NULL       0       /* not in an eval */
 773 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 774 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 775 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 776 #define EVAL_INREQUIRE  8       /* The code is being required. */
 777
 778 /* Support for switching (stack and block) contexts.
 779  * This ensures magic doesn't invalidate local stack and cx pointers.
 780  */
 781
 782 #define PERLSI_UNKNOWN          -1
 783 #define PERLSI_UNDEF            0
 784 #define PERLSI_MAIN             1
 785 #define PERLSI_MAGIC            2
 786 #define PERLSI_SORT             3
 787 #define PERLSI_SIGNAL           4
 788 #define PERLSI_OVERLOAD         5
 789 #define PERLSI_DESTROY          6
 790 #define PERLSI_WARNHOOK         7
 791 #define PERLSI_DIEHOOK          8
 792 #define PERLSI_REQUIRE          9
 793
 794 struct stackinfo {
 795     AV *                si_stack;       /* stack for current runlevel */
 796     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 797     struct stackinfo *  si_prev;
 798     struct stackinfo *  si_next;
 799     I32                 si_cxix;        /* current context index */
 800     I32                 si_cxmax;       /* maximum allocated index */
 801     I32                 si_type;        /* type of runlevel */
 802     I32                 si_markoff;     /* offset where markstack begins for us.
 803                                          * currently used only with DEBUGGING,
 804                                          * but not #ifdef-ed for bincompat */
 805 };
 806
 807 typedef struct stackinfo PERL_SI;
 808
 809 #define cxstack         (PL_curstackinfo->si_cxstack)
 810 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 811 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 812
 813 #ifdef DEBUGGING
 814 #  define       SET_MARK_OFFSET \
 815     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 816 #else
 817 #  define       SET_MARK_OFFSET NOOP
 818 #endif
 819
 820 #define PUSHSTACKi(type) \
 821     STMT_START {                                                        \
 822         PERL_SI *next = PL_curstackinfo->si_next;                       \
 823         if (!next) {                                                    \
 824             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 825             next->si_prev = PL_curstackinfo;                            \
 826             PL_curstackinfo->si_next = next;                            \
 827         }                                                               \
 828         next->si_type = type;                                           \
 829         next->si_cxix = -1;                                             \
 830         AvFILLp(next->si_stack) = 0;                                    \
 831         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 832         PL_curstackinfo = next;                                         \
 833         SET_MARK_OFFSET;                                                \
 834     } STMT_END
 835
 836 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 837
 838 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 839  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 840 #define POPSTACK \
 841     STMT_START {                                                        \
 842         dSP;                                                            \
 843         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 844         if (!prev) {                                                    \
 845             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 846             my_exit(1);                                                 \
 847         }                                                               \
 848         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 849         /* don't free prev here, free them all at the END{} */          \
 850         PL_curstackinfo = prev;                                         \
 851     } STMT_END
 852
 853 #define POPSTACK_TO(s) \
 854     STMT_START {                                                        \
 855         while (PL_curstack != s) {                                      \
 856             dounwind(-1);                                               \
 857             POPSTACK;                                                   \
 858         }                                                               \
 859     } STMT_END
 860
 861 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 862 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 863
 864 /*
 865 =head1 Multicall Functions
 866
 867 =for apidoc Ams||dMULTICALL
 868 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 869
 870 =for apidoc Ams||PUSH_MULTICALL
 871 Opening bracket for a lightweight callback.
 872 See L<perlcall/Lightweight Callbacks>.
 873
 874 =for apidoc Ams||MULTICALL
 875 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 876
 877 =for apidoc Ams||POP_MULTICALL
 878 Closing bracket for a lightweight callback.
 879 See L<perlcall/Lightweight Callbacks>.
 880
 881 =cut
 882 */
 883
 884 #define dMULTICALL \
 885     SV **newsp;                 /* set by POPBLOCK */                   \
 886     PERL_CONTEXT *cx;                                                   \
 887     CV *multicall_cv;                                                   \
 888     OP *multicall_cop;                                                  \
 889     bool multicall_oldcatch;                                            \
 890     U8 hasargs = 0              /* used by PUSHSUB */
 891
 892 #define PUSH_MULTICALL(the_cv) \
 893     STMT_START {                                                        \
 894         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 895         CV * const cv = _nOnclAshIngNamE_;                              \
 896         AV * const padlist = CvPADLIST(cv);                             \
 897         ENTER;                                                          \
 898         multicall_oldcatch = CATCH_GET;                                 \
 899         SAVETMPS; SAVEVPTR(PL_op);                                      \
 900         CATCH_SET(TRUE);                                                \
 901         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 902         PUSHSUB(cx);                                                    \
 903         if (++CvDEPTH(cv) >= 2) {                                       \
 904             PERL_STACK_OVERFLOW_CHECK();                                \
 905             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 906         }                                                               \
 907         SAVECOMPPAD();                                                  \
 908         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 909         multicall_cv = cv;                                              \
 910         multicall_cop = CvSTART(cv);                                    \
 911     } STMT_END
 912
 913 #define MULTICALL \
 914     STMT_START {                                                        \
 915         PL_op = multicall_cop;                                          \
 916         CALLRUNOPS(aTHX);                                               \
 917     } STMT_END
 918
 919 #define POP_MULTICALL \
 920     STMT_START {                                                        \
 921         LEAVESUB(multicall_cv);                                         \
 922         CvDEPTH(multicall_cv)--;                                        \
 923         POPBLOCK(cx,PL_curpm);                                          \
 924         CATCH_SET(multicall_oldcatch);                                  \
 925         LEAVE;                                                          \
 926     } STMT_END
 927
 928 /*
 929  * Local variables:
 930  * c-indentation-style: bsd
 931  * c-basic-offset: 4
 932  * indent-tabs-mode: t
 933  * End:
 934  *
 935  * ex: set ts=8 sts=4 sw=4 noet:
 936  */