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)                                                  \
 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     PAD         *oldcomppad; /* Also used for the GV, if targoffset is 0 */
 440     /* This is also accesible via cx->blk_loop.my_op->op_targ */
 441     PADOFFSET   targoffset;
 442 #else
 443     OP *        next_op;
 444     SV **       itervar;
 445 #endif
 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.oldcomppad                                       \
 465          ? (CxPADLOOP(c)                                                \
 466             ? &CX_CURPAD_SV( (c)->blk_loop, (c)->blk_loop.targoffset )  \
 467             : &GvSV((GV*)(c)->blk_loop.oldcomppad))                     \
 468          : (SV**)NULL)
 469 #  define CX_ITERDATA_SET(cx,idata,o)                                   \
 470         if ((cx->blk_loop.targoffset = (o)))                            \
 471             CX_CURPAD_SAVE(cx->blk_loop);                               \
 472         else                                                            \
 473             cx->blk_loop.oldcomppad = (idata);
 474 #else
 475 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 476 #  define CX_ITERDATA_SET(cx,ivar,o)                                    \
 477         cx->blk_loop.itervar = (SV**)(ivar);
 478 #endif
 479 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
 480 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 481 #define CxLVAL(c)       (0 + (c)->blk_u16)
 482
 483 #ifdef USE_ITHREADS
 484 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
 485 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
 486 #else
 487 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
 488 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
 489 #endif
 490
 491 #define PUSHLOOP_PLAIN(cx, s)                                           \
 492         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 493         cx->blk_loop.my_op = cLOOP;                                     \
 494         PUSHLOOP_OP_NEXT;                                               \
 495         cx->blk_loop.state_u.ary.ary = NULL;                            \
 496         cx->blk_loop.state_u.ary.ix = 0;                                \
 497         CX_ITERDATA_SET(cx, NULL, 0);
 498
 499 #define PUSHLOOP_FOR(cx, dat, s, offset)                                \
 500         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 501         cx->blk_loop.my_op = cLOOP;                                     \
 502         PUSHLOOP_OP_NEXT;                                               \
 503         cx->blk_loop.state_u.ary.ary = NULL;                            \
 504         cx->blk_loop.state_u.ary.ix = 0;                                \
 505         CX_ITERDATA_SET(cx, dat, offset);
 506
 507 #define POPLOOP(cx)                                                     \
 508         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
 509             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
 510             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
 511         }                                                               \
 512         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
 513             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
 514
 515 /* given/when context */
 516 struct block_givwhen {
 517         OP *leave_op;
 518 };
 519
 520 #define PUSHGIVEN(cx)                                                   \
 521         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 522
 523 #define PUSHWHEN PUSHGIVEN
 524
 525 /* context common to subroutines, evals and loops */
 526 struct block {
 527     U8          blku_type;      /* what kind of context this is */
 528     U8          blku_gimme;     /* is this block running in list context? */
 529     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 530     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 531     COP *       blku_oldcop;    /* old curcop pointer */
 532     I32         blku_oldmarksp; /* mark stack index */
 533     I32         blku_oldscopesp;        /* scope stack index */
 534     PMOP *      blku_oldpm;     /* values of pattern match vars */
 535
 536     union {
 537         struct block_sub        blku_sub;
 538         struct block_format     blku_format;
 539         struct block_eval       blku_eval;
 540         struct block_loop       blku_loop;
 541         struct block_givwhen    blku_givwhen;
 542     } blk_u;
 543 };
 544 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 545 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 546 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 547 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 548 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 549 #define blk_gimme       cx_u.cx_blk.blku_gimme
 550 #define blk_u16         cx_u.cx_blk.blku_u16
 551 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 552 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 553 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 554 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 555 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 556
 557 /* Enter a block. */
 558 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 559         cx->cx_type             = t,                                    \
 560         cx->blk_oldsp           = sp - PL_stack_base,                   \
 561         cx->blk_oldcop          = PL_curcop,                            \
 562         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 563         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 564         cx->blk_oldpm           = PL_curpm,                             \
 565         cx->blk_gimme           = (U8)gimme;                            \
 566         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 567                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 568
 569 /* Exit a block (RETURN and LAST). */
 570 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 571         newsp            = PL_stack_base + cx->blk_oldsp,               \
 572         PL_curcop        = cx->blk_oldcop,                              \
 573         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 574         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 575         pm               = cx->blk_oldpm,                               \
 576         gimme            = cx->blk_gimme;                               \
 577         DEBUG_SCOPE("POPBLOCK");                                        \
 578         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 579                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 580
 581 /* Continue a block elsewhere (NEXT and REDO). */
 582 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 583         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 584         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 585         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 586         PL_curpm         = cx->blk_oldpm;                               \
 587         DEBUG_SCOPE("TOPBLOCK");
 588
 589 /* substitution context */
 590 struct subst {
 591     U8          sbu_type;       /* what kind of context this is */
 592     U8          sbu_rflags;
 593     U16         sbu_rxtainted;  /* matches struct block */
 594     I32         sbu_iters;
 595     I32         sbu_maxiters;
 596     I32         sbu_oldsave;
 597     char *      sbu_orig;
 598     SV *        sbu_dstr;
 599     SV *        sbu_targ;
 600     char *      sbu_s;
 601     char *      sbu_m;
 602     char *      sbu_strend;
 603     void *      sbu_rxres;
 604     REGEXP *    sbu_rx;
 605 };
 606 #define sb_iters        cx_u.cx_subst.sbu_iters
 607 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 608 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 609 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 610 #define sb_once         cx_u.cx_subst.sbu_once
 611 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 612 #define sb_orig         cx_u.cx_subst.sbu_orig
 613 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 614 #define sb_targ         cx_u.cx_subst.sbu_targ
 615 #define sb_s            cx_u.cx_subst.sbu_s
 616 #define sb_m            cx_u.cx_subst.sbu_m
 617 #define sb_strend       cx_u.cx_subst.sbu_strend
 618 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 619 #define sb_rx           cx_u.cx_subst.sbu_rx
 620
 621 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 622         cx->sb_iters            = iters,                                \
 623         cx->sb_maxiters         = maxiters,                             \
 624         cx->sb_rflags           = r_flags,                              \
 625         cx->sb_oldsave          = oldsave,                              \
 626         cx->sb_rxtainted        = rxtainted,                            \
 627         cx->sb_orig             = orig,                                 \
 628         cx->sb_dstr             = dstr,                                 \
 629         cx->sb_targ             = targ,                                 \
 630         cx->sb_s                = s,                                    \
 631         cx->sb_m                = m,                                    \
 632         cx->sb_strend           = strend,                               \
 633         cx->sb_rxres            = NULL,                                 \
 634         cx->sb_rx               = rx,                                   \
 635         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
 636         rxres_save(&cx->sb_rxres, rx);                                  \
 637         (void)ReREFCNT_inc(rx)
 638
 639 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
 640
 641 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 642         rxres_free(&cx->sb_rxres);                                      \
 643         ReREFCNT_dec(cx->sb_rx)
 644
 645 struct context {
 646     union {
 647         struct block    cx_blk;
 648         struct subst    cx_subst;
 649     } cx_u;
 650 };
 651 #define cx_type cx_u.cx_subst.sbu_type
 652
 653 /* If you re-order these, there is also an array of uppercase names in perl.h
 654    and a static array of context names in pp_ctl.c  */
 655 #define CXTYPEMASK      0xf
 656 #define CXt_NULL        0
 657 #define CXt_WHEN        1
 658 #define CXt_BLOCK       2
 659 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
 660    jump table in pp_ctl.c
 661    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
 662 */
 663 #define CXt_GIVEN       3
 664 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
 665 #define CXt_LOOP_FOR    4
 666 #define CXt_LOOP_PLAIN  5
 667 #define CXt_LOOP_LAZYSV 6
 668 #define CXt_LOOP_LAZYIV 7
 669 #define CXt_SUB         8
 670 #define CXt_FORMAT      9
 671 #define CXt_EVAL       10
 672 #define CXt_SUBST      11
 673 /* SUBST doesn't feature in all switch statements.  */
 674
 675 /* private flags for CXt_SUB and CXt_NULL
 676    However, this is checked in many places which do not check the type, so
 677    this bit needs to be kept clear for most everything else. For reasons I
 678    haven't investigated, it can coexist with CXp_FOR_DEF */
 679 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
 680                                    tear down context on exit). */
 681
 682 /* private flags for CXt_SUB and CXt_FORMAT */
 683 #define CXp_HASARGS     0x20
 684
 685 /* private flags for CXt_EVAL */
 686 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
 687 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
 688
 689 /* private flags for CXt_LOOP */
 690 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
 691 #ifdef USE_ITHREADS
 692 #  define CxPADLOOP(c)  ((c)->blk_loop.targoffset)
 693 #endif
 694
 695 /* private flags for CXt_SUBST */
 696 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
 697
 698 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 699 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
 700 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 701                          == CXp_MULTICALL)
 702 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 703                          == (CXt_EVAL|CXp_REAL))
 704 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 705                          == (CXt_EVAL|CXp_TRYBLOCK))
 706 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
 707 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
 708                          && ((c)->cx_type & CXp_FOR_DEF))
 709
 710 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 711
 712 /*
 713 =head1 "Gimme" Values
 714 */
 715
 716 /*
 717 =for apidoc AmU||G_SCALAR
 718 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 719 L<perlcall>.
 720
 721 =for apidoc AmU||G_ARRAY
 722 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 723 L<perlcall>.
 724
 725 =for apidoc AmU||G_VOID
 726 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 727
 728 =for apidoc AmU||G_DISCARD
 729 Indicates that arguments returned from a callback should be discarded.  See
 730 L<perlcall>.
 731
 732 =for apidoc AmU||G_EVAL
 733
 734 Used to force a Perl C<eval> wrapper around a callback.  See
 735 L<perlcall>.
 736
 737 =for apidoc AmU||G_NOARGS
 738
 739 Indicates that no arguments are being sent to a callback.  See
 740 L<perlcall>.
 741
 742 =cut
 743 */
 744
 745 #define G_SCALAR        2
 746 #define G_ARRAY         3
 747 #define G_VOID          1
 748 #define G_WANT          3
 749
 750 /* extra flags for Perl_call_* routines */
 751 #define G_DISCARD       4       /* Call FREETMPS.
 752                                    Don't change this without consulting the
 753                                    hash actions codes defined in hv.h */
 754 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
 755 #define G_NOARGS       16       /* Don't construct a @_ array. */
 756 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
 757 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
 758 #define G_METHOD      128       /* Calling method. */
 759 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 760                                    fold_constants. */
 761
 762 /* flag bits for PL_in_eval */
 763 #define EVAL_NULL       0       /* not in an eval */
 764 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 765 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 766 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 767 #define EVAL_INREQUIRE  8       /* The code is being required. */
 768
 769 /* Support for switching (stack and block) contexts.
 770  * This ensures magic doesn't invalidate local stack and cx pointers.
 771  */
 772
 773 #define PERLSI_UNKNOWN          -1
 774 #define PERLSI_UNDEF            0
 775 #define PERLSI_MAIN             1
 776 #define PERLSI_MAGIC            2
 777 #define PERLSI_SORT             3
 778 #define PERLSI_SIGNAL           4
 779 #define PERLSI_OVERLOAD         5
 780 #define PERLSI_DESTROY          6
 781 #define PERLSI_WARNHOOK         7
 782 #define PERLSI_DIEHOOK          8
 783 #define PERLSI_REQUIRE          9
 784
 785 struct stackinfo {
 786     AV *                si_stack;       /* stack for current runlevel */
 787     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 788     struct stackinfo *  si_prev;
 789     struct stackinfo *  si_next;
 790     I32                 si_cxix;        /* current context index */
 791     I32                 si_cxmax;       /* maximum allocated index */
 792     I32                 si_type;        /* type of runlevel */
 793     I32                 si_markoff;     /* offset where markstack begins for us.
 794                                          * currently used only with DEBUGGING,
 795                                          * but not #ifdef-ed for bincompat */
 796 };
 797
 798 typedef struct stackinfo PERL_SI;
 799
 800 #define cxstack         (PL_curstackinfo->si_cxstack)
 801 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 802 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 803
 804 #ifdef DEBUGGING
 805 #  define       SET_MARK_OFFSET \
 806     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 807 #else
 808 #  define       SET_MARK_OFFSET NOOP
 809 #endif
 810
 811 #define PUSHSTACKi(type) \
 812     STMT_START {                                                        \
 813         PERL_SI *next = PL_curstackinfo->si_next;                       \
 814         if (!next) {                                                    \
 815             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 816             next->si_prev = PL_curstackinfo;                            \
 817             PL_curstackinfo->si_next = next;                            \
 818         }                                                               \
 819         next->si_type = type;                                           \
 820         next->si_cxix = -1;                                             \
 821         AvFILLp(next->si_stack) = 0;                                    \
 822         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 823         PL_curstackinfo = next;                                         \
 824         SET_MARK_OFFSET;                                                \
 825     } STMT_END
 826
 827 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 828
 829 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 830  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 831 #define POPSTACK \
 832     STMT_START {                                                        \
 833         dSP;                                                            \
 834         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 835         if (!prev) {                                                    \
 836             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 837             my_exit(1);                                                 \
 838         }                                                               \
 839         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 840         /* don't free prev here, free them all at the END{} */          \
 841         PL_curstackinfo = prev;                                         \
 842     } STMT_END
 843
 844 #define POPSTACK_TO(s) \
 845     STMT_START {                                                        \
 846         while (PL_curstack != s) {                                      \
 847             dounwind(-1);                                               \
 848             POPSTACK;                                                   \
 849         }                                                               \
 850     } STMT_END
 851
 852 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 853 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 854
 855 /*
 856 =head1 Multicall Functions
 857
 858 =for apidoc Ams||dMULTICALL
 859 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 860
 861 =for apidoc Ams||PUSH_MULTICALL
 862 Opening bracket for a lightweight callback.
 863 See L<perlcall/Lightweight Callbacks>.
 864
 865 =for apidoc Ams||MULTICALL
 866 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 867
 868 =for apidoc Ams||POP_MULTICALL
 869 Closing bracket for a lightweight callback.
 870 See L<perlcall/Lightweight Callbacks>.
 871
 872 =cut
 873 */
 874
 875 #define dMULTICALL \
 876     SV **newsp;                 /* set by POPBLOCK */                   \
 877     PERL_CONTEXT *cx;                                                   \
 878     CV *multicall_cv;                                                   \
 879     OP *multicall_cop;                                                  \
 880     bool multicall_oldcatch;                                            \
 881     U8 hasargs = 0              /* used by PUSHSUB */
 882
 883 #define PUSH_MULTICALL(the_cv) \
 884     STMT_START {                                                        \
 885         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 886         CV * const cv = _nOnclAshIngNamE_;                              \
 887         AV * const padlist = CvPADLIST(cv);                             \
 888         ENTER;                                                          \
 889         multicall_oldcatch = CATCH_GET;                                 \
 890         SAVETMPS; SAVEVPTR(PL_op);                                      \
 891         CATCH_SET(TRUE);                                                \
 892         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 893         PUSHSUB(cx);                                                    \
 894         if (++CvDEPTH(cv) >= 2) {                                       \
 895             PERL_STACK_OVERFLOW_CHECK();                                \
 896             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 897         }                                                               \
 898         SAVECOMPPAD();                                                  \
 899         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 900         multicall_cv = cv;                                              \
 901         multicall_cop = CvSTART(cv);                                    \
 902     } STMT_END
 903
 904 #define MULTICALL \
 905     STMT_START {                                                        \
 906         PL_op = multicall_cop;                                          \
 907         CALLRUNOPS(aTHX);                                               \
 908     } STMT_END
 909
 910 #define POP_MULTICALL \
 911     STMT_START {                                                        \
 912         LEAVESUB(multicall_cv);                                         \
 913         CvDEPTH(multicall_cv)--;                                        \
 914         POPBLOCK(cx,PL_curpm);                                          \
 915         CATCH_SET(multicall_oldcatch);                                  \
 916         LEAVE;                                                          \
 917     } STMT_END
 918
 919 /*
 920  * Local variables:
 921  * c-indentation-style: bsd
 922  * c-basic-offset: 4
 923  * indent-tabs-mode: t
 924  * End:
 925  *
 926  * ex: set ts=8 sts=4 sw=4 noet:
 927  */