cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   4  *    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
   5  *
   6  *    You may distribute under the terms of either the GNU General Public
   7  *    License or the Artistic License, as specified in the README file.
   8  *
   9  * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
  10  * and OP_SETSTATE that (loosely speaking) are separate statements.
  11  * They hold information important for lexical state and error reporting.
  12  * At run time, PL_curcop is set to point to the most recently executed cop,
  13  * and thus can be used to determine our current state.
  14  */
  15
  16 /* A jmpenv packages the state required to perform a proper non-local jump.
  17  * Note that there is a start_env initialized when perl starts, and top_env
  18  * points to this initially, so top_env should always be non-null.
  19  *
  20  * Existence of a non-null top_env->je_prev implies it is valid to call
  21  * longjmp() at that runlevel (we make sure start_env.je_prev is always
  22  * null to ensure this).
  23  *
  24  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
  25  * establish a local jmpenv to handle exception traps.  Care must be taken
  26  * to restore the previous value of je_mustcatch before exiting the
  27  * stack frame iff JMPENV_PUSH was not called in that stack frame.
  28  * GSAR 97-03-27
  29  */
  30
  31 struct jmpenv {
  32     struct jmpenv *     je_prev;
  33     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
  34     int                 je_ret;         /* last exception thrown */
  35     bool                je_mustcatch;   /* need to call longjmp()? */
  36 };
  37
  38 typedef struct jmpenv JMPENV;
  39
  40 #ifdef OP_IN_REGISTER
  41 #define OP_REG_TO_MEM   PL_opsave = op
  42 #define OP_MEM_TO_REG   op = PL_opsave
  43 #else
  44 #define OP_REG_TO_MEM   NOOP
  45 #define OP_MEM_TO_REG   NOOP
  46 #endif
  47
  48 /*
  49  * How to build the first jmpenv.
  50  *
  51  * top_env needs to be non-zero. It points to an area
  52  * in which longjmp() stuff is stored, as C callstack
  53  * info there at least is thread specific this has to
  54  * be per-thread. Otherwise a 'die' in a thread gives
  55  * that thread the C stack of last thread to do an eval {}!
  56  */
  57
  58 #define JMPENV_BOOTSTRAP \
  59     STMT_START {                                \
  60         Zero(&PL_start_env, 1, JMPENV);         \
  61         PL_start_env.je_ret = -1;               \
  62         PL_start_env.je_mustcatch = TRUE;       \
  63         PL_top_env = &PL_start_env;             \
  64     } STMT_END
  65
  66 /*
  67  *   PERL_FLEXIBLE_EXCEPTIONS
  68  *
  69  * All the flexible exceptions code has been removed.
  70  * See the following threads for details:
  71  *
  72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
  73  *
  74  * Joshua's original patches (which weren't applied) and discussion:
  75  *
  76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
  77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
  78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
  79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
  80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
  81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
  82  *
  83  * Chip's reworked patch and discussion:
  84  *
  85  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
  86  *
  87  * The flaw in these patches (which went unnoticed at the time) was
  88  * that they moved some code that could potentially die() out of the
  89  * region protected by the setjmp()s.  This caused exceptions within
  90  * END blocks and such to not be handled by the correct setjmp().
  91  *
  92  * The original patches that introduces flexible exceptions were:
  93  *
  94  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
  95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
  96  */
  97
  98 #define dJMPENV         JMPENV cur_env
  99
 100 #define JMPENV_PUSH(v) \
 101     STMT_START {                                                        \
 102         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
 103                          (void*)&cur_env, (void*)PL_top_env));                  \
 104         cur_env.je_prev = PL_top_env;                                   \
 105         OP_REG_TO_MEM;                                                  \
 106         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 107         OP_MEM_TO_REG;                                                  \
 108         PL_top_env = &cur_env;                                          \
 109         cur_env.je_mustcatch = FALSE;                                   \
 110         (v) = cur_env.je_ret;                                           \
 111     } STMT_END
 112
 113 #define JMPENV_POP \
 114     STMT_START {                                                        \
 115         DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
 116                          (void*)PL_top_env, (void*)cur_env.je_prev));                   \
 117         PL_top_env = cur_env.je_prev;                                   \
 118     } STMT_END
 119
 120 #define JMPENV_JUMP(v) \
 121     STMT_START {                                                \
 122         OP_REG_TO_MEM;                                          \
 123         if (PL_top_env->je_prev)                                \
 124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 125         if ((v) == 2)                                           \
 126             PerlProc_exit(STATUS_EXIT);                         \
 127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 128         PerlProc_exit(1);                                       \
 129     } STMT_END
 130
 131 #define CATCH_GET               (PL_top_env->je_mustcatch)
 132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
 133
 134
 135 #include "mydtrace.h"
 136
 137 struct cop {
 138     BASEOP
 139     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
 140        an exact multiple of 8 bytes to save structure padding.  */
 141     line_t      cop_line;       /* line # of this command */
 142     char *      cop_label;      /* label for this construct */
 143 #ifdef USE_ITHREADS
 144     char *      cop_stashpv;    /* package line was compiled in */
 145     char *      cop_file;       /* file name the following line # is from */
 146 #else
 147     HV *        cop_stash;      /* package line was compiled in */
 148     GV *        cop_filegv;     /* file the following line # is from */
 149 #endif
 150     U32         cop_hints;      /* hints bits from pragmata */
 151     U32         cop_seq;        /* parse sequence number */
 152     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 153     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 154     /* compile time state of %^H.  See the comment in op.c for how this is
 155        used to recreate a hash to return from caller.  */
 156     struct refcounted_he * cop_hints_hash;
 157 };
 158
 159 #ifdef USE_ITHREADS
 160 #  define CopFILE(c)            ((c)->cop_file)
 161 #  define CopFILEGV(c)          (CopFILE(c) \
 162                                  ? gv_fetchfile(CopFILE(c)) : NULL)
 163
 164 #  ifdef NETWARE
 165 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
 166 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
 167 #  else
 168 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
 169 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
 170 #  endif
 171
 172 #  define CopFILESV(c)          (CopFILE(c) \
 173                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 174 #  define CopFILEAV(c)          (CopFILE(c) \
 175                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
 176 #  ifdef DEBUGGING
 177 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
 178                                    GvAV(gv_fetchfile(CopFILE(c))))
 179 #  else
 180 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
 181 #  endif
 182 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
 183
 184 #  ifdef NETWARE
 185 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
 186 #  else
 187 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
 188 #  endif
 189
 190 #  define CopSTASH(c)           (CopSTASHPV(c) \
 191                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
 192 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
 193 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
 194 #  define CopLABEL(c)           ((c)->cop_label)
 195 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
 196 #  ifdef NETWARE
 197 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
 198 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
 199 #    define CopLABEL_free(c) SAVECOPLABEL_FREE(c)
 200 #    define CopLABEL_alloc(pv)  ((pv)?savepv(pv):NULL)
 201 #  else
 202 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
 203 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
 204 #    define CopLABEL_free(c)    (PerlMemShared_free(CopLABEL(c)),(CopLABEL(c) = NULL))
 205 #    define CopLABEL_alloc(pv)  ((pv)?savesharedpv(pv):NULL)
 206 #  endif
 207 #else
 208 #  define CopFILEGV(c)          ((c)->cop_filegv)
 209 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 210 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
 211 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
 212 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
 213 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
 214 #  ifdef DEBUGGING
 215 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
 216 #  else
 217 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
 218 # endif
 219 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
 220                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
 221 #  define CopSTASH(c)           ((c)->cop_stash)
 222 #  define CopLABEL(c)           ((c)->cop_label)
 223 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
 224 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
 225    /* cop_stash is not refcounted */
 226 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 227 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
 228 #  define CopLABEL_alloc(pv)    ((pv)?savepv(pv):NULL)
 229 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
 230 #  define CopSTASH_free(c)
 231 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
 232 #  define CopLABEL_free(c)      (Safefree(CopLABEL(c)),(CopLABEL(c) = NULL))
 233
 234 #endif /* USE_ITHREADS */
 235
 236 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
 237 #define CopLINE(c)              ((c)->cop_line)
 238 #define CopLINE_inc(c)          (++CopLINE(c))
 239 #define CopLINE_dec(c)          (--CopLINE(c))
 240 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
 241
 242 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
 243 #ifdef MACOS_TRADITIONAL
 244 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
 245 #else
 246 #  define OutCopFILE(c) CopFILE(c)
 247 #endif
 248
 249 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
 250    HINT_ARYBASE is set to indicate this.
 251    Setting it is ineficient due to the need to create 2 mortal SVs, but as
 252    using $[ is highly discouraged, no sane Perl code will be using it.  */
 253 #define CopARYBASE_get(c)       \
 254         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
 255          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
 256                                          "$[", 2, 0, 0))                \
 257          : 0)
 258 #define CopARYBASE_set(c, b) STMT_START { \
 259         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
 260             (c)->cop_hints |= HINT_ARYBASE;                             \
 261             if ((c) == &PL_compiling)                                   \
 262                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
 263             (c)->cop_hints_hash                                         \
 264                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
 265                                         newSVpvs_flags("$[", SVs_TEMP), \
 266                                         sv_2mortal(newSViv(b)));        \
 267         }                                                               \
 268     } STMT_END
 269
 270 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
 271 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
 272 #define CopHINTS_set(c, h)      STMT_START {                            \
 273                                     (c)->cop_hints = (h);               \
 274                                 } STMT_END
 275
 276 /*
 277  * Here we have some enormously heavy (or at least ponderous) wizardry.
 278  */
 279
 280 /* subroutine context */
 281 struct block_sub {
 282     CV *        cv;
 283     OP *        retop;  /* op to execute on exit from sub */
 284     U8          hasargs;
 285     U8          lval;           /* XXX merge lval and hasargs? */
 286     /* Above here is the same for sub and format.  */
 287     AV *        savearray;
 288     AV *        argarray;
 289     I32         olddepth;
 290     PAD         *oldcomppad;
 291 };
 292
 293
 294 /* format context */
 295 struct block_format {
 296     CV *        cv;
 297     OP *        retop;  /* op to execute on exit from sub */
 298     U8          hasargs;
 299     U8          lval;           /* XXX merge lval and hasargs? */
 300     /* Above here is the same for sub and format.  */
 301     GV *        gv;
 302     GV *        dfoutgv;
 303 };
 304
 305 /* base for the next two macros. Don't use directly.
 306  * Note that the refcnt of the cv is incremented twice;  The CX one is
 307  * decremented by LEAVESUB, the other by LEAVE. */
 308
 309 #define PUSHSUB_BASE(cx)                                                \
 310         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
 311                 CopFILE((COP*)CvSTART(cv)),                             \
 312                 CopLINE((COP*)CvSTART(cv)));                            \
 313                                                                         \
 314         cx->blk_sub.cv = cv;                                            \
 315         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 316         cx->blk_sub.hasargs = hasargs;                                  \
 317         cx->blk_sub.retop = NULL;                                       \
 318         if (!CvDEPTH(cv)) {                                             \
 319             SvREFCNT_inc_simple_void_NN(cv);                            \
 320             SvREFCNT_inc_simple_void_NN(cv);                            \
 321             SAVEFREESV(cv);                                             \
 322         }
 323
 324
 325 #define PUSHSUB(cx)                                                     \
 326         PUSHSUB_BASE(cx)                                                \
 327         cx->blk_sub.lval = PL_op->op_private &                          \
 328                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 329
 330 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 331 #define PUSHSUB_DB(cx)                                                  \
 332         PUSHSUB_BASE(cx)                                                \
 333         cx->blk_sub.lval = 0;
 334
 335
 336 #define PUSHFORMAT(cx, retop)                                           \
 337         cx->blk_format.cv = cv;                                         \
 338         cx->blk_format.gv = gv;                                         \
 339         cx->blk_format.retop = (retop);                                 \
 340         cx->blk_format.hasargs = 0;                                     \
 341         cx->blk_format.dfoutgv = PL_defoutgv;                           \
 342         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
 343
 344 #define POP_SAVEARRAY()                                         \
 345     STMT_START {                                                        \
 346         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 347         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 348     } STMT_END
 349
 350 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 351  * leave any (a fast av_clear(ary), basically) */
 352 #define CLEAR_ARGARRAY(ary) \
 353     STMT_START {                                                        \
 354         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 355         AvARRAY(ary) = AvALLOC(ary);                                    \
 356         AvFILLp(ary) = -1;                                              \
 357     } STMT_END
 358
 359 #define POPSUB(cx,sv)                                                   \
 360     STMT_START {                                                        \
 361         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
 362                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
 363                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
 364                                                                         \
 365         if (cx->blk_sub.hasargs) {                                      \
 366             POP_SAVEARRAY();                                            \
 367             /* abandon @_ if it got reified */                          \
 368             if (AvREAL(cx->blk_sub.argarray)) {                         \
 369                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
 370                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 371                 cx->blk_sub.argarray = newAV();                         \
 372                 av_extend(cx->blk_sub.argarray, fill);                  \
 373                 AvREIFY_only(cx->blk_sub.argarray);                     \
 374                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
 375             }                                                           \
 376             else {                                                      \
 377                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 378             }                                                           \
 379         }                                                               \
 380         sv = (SV*)cx->blk_sub.cv;                                       \
 381         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 382             sv = NULL;                                          \
 383     } STMT_END
 384
 385 #define LEAVESUB(sv)                                                    \
 386     STMT_START {                                                        \
 387         if (sv)                                                         \
 388             SvREFCNT_dec(sv);                                           \
 389     } STMT_END
 390
 391 #define POPFORMAT(cx)                                                   \
 392         setdefout(cx->blk_format.dfoutgv);                              \
 393         SvREFCNT_dec(cx->blk_format.dfoutgv);
 394
 395 /* eval context */
 396 struct block_eval {
 397     U8          old_in_eval;
 398     U16         old_op_type;
 399     SV *        old_namesv;
 400     OP *        old_eval_root;
 401     SV *        cur_text;
 402     CV *        cv;
 403     OP *        retop;  /* op to execute on exit from eval */
 404     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 405 };
 406
 407 #define PUSHEVAL(cx,n,fgv)                                              \
 408     STMT_START {                                                        \
 409         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 410         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 411         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 412         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 413         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 414         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 415         cx->blk_eval.retop = NULL;                                      \
 416         cx->blk_eval.cur_top_env = PL_top_env;                          \
 417     } STMT_END
 418
 419 #define POPEVAL(cx)                                                     \
 420     STMT_START {                                                        \
 421         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 422         optype = cx->blk_eval.old_op_type;                              \
 423         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 424         if (cx->blk_eval.old_namesv)                                    \
 425             sv_2mortal(cx->blk_eval.old_namesv);                        \
 426     } STMT_END
 427
 428 /* loop context */
 429 struct block_loop {
 430     I32         resetsp;
 431     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 432     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
 433         why next_op is conditionally defined below.)  */
 434 #ifdef USE_ITHREADS
 435     void *      iterdata;
 436     PAD         *oldcomppad;
 437 #else
 438     OP *        next_op;
 439     SV **       itervar;
 440 #endif
 441     SV *        itersave;
 442     /* (from inspection of source code) for a .. range of strings this is the
 443        current string.  */
 444     SV *        iterlval;
 445     /* (from inspection of source code) for a foreach loop this is the array
 446        being iterated over. For a .. range of numbers it's the current value.
 447        A check is often made on the SvTYPE of iterary to determine whether
 448        we are iterating over an array or a range. (numbers or strings)  */
 449     AV *        iterary;
 450     IV          iterix;
 451     /* (from inspection of source code) for a .. range of numbers this is the
 452        maximum value.  */
 453     IV          itermax;
 454 };
 455 /* It might be possible to squeeze this structure further. As best I can tell
 456    itermax and iterlval are never used at the same time, so it might be possible
 457    to make them into a union. However, I'm not confident that there are enough
 458    flag bits/NULLable pointers in this structure alone to encode which is
 459    active. There is, however, U8 of space free in struct block, which could be
 460    used. Right now it may not be worth squeezing this structure further, as it's
 461    the largest part of struct block, and currently struct block is 64 bytes on
 462    an ILP32 system, which will give good cache alignment.
 463 */
 464
 465 #ifdef USE_ITHREADS
 466 #  define CxITERVAR(c)                                                  \
 467         ((c)->blk_loop.iterdata                                         \
 468          ? (CxPADLOOP(cx)                                               \
 469             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 470                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 471             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 472          : (SV**)NULL)
 473 #  define CX_ITERDATA_SET(cx,idata)                                     \
 474         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 475         if ((cx->blk_loop.iterdata = (idata)))                          \
 476             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 477         else                                                            \
 478             cx->blk_loop.itersave = NULL;
 479 #else
 480 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 481 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 482         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 483             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 484         else                                                            \
 485             cx->blk_loop.itersave = NULL;
 486 #endif
 487 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
 488
 489 #ifdef USE_ITHREADS
 490 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
 491 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
 492 #else
 493 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
 494 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
 495 #endif
 496
 497 #define PUSHLOOP(cx, dat, s)                                            \
 498         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 499         cx->blk_loop.my_op = cLOOP;                                     \
 500         PUSHLOOP_OP_NEXT;                                               \
 501         cx->blk_loop.iterlval = NULL;                                   \
 502         cx->blk_loop.iterary = NULL;                                    \
 503         cx->blk_loop.iterix = -1;                                       \
 504         CX_ITERDATA_SET(cx,dat);
 505
 506 #define POPLOOP(cx)                                                     \
 507         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 508         if (CxITERVAR(cx)) {                                            \
 509             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 510                 SV ** const s_v_p = CxITERVAR(cx);                      \
 511                 sv_2mortal(*s_v_p);                                     \
 512                 *s_v_p = cx->blk_loop.itersave;                         \
 513             }                                                           \
 514             else {                                                      \
 515                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 516             }                                                           \
 517         }                                                               \
 518         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 519             SvREFCNT_dec(cx->blk_loop.iterary);
 520
 521 /* given/when context */
 522 struct block_givwhen {
 523         OP *leave_op;
 524 };
 525
 526 #define PUSHGIVEN(cx)                                                   \
 527         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 528
 529 #define PUSHWHEN PUSHGIVEN
 530
 531 /* context common to subroutines, evals and loops */
 532 struct block {
 533     U16         blku_type;      /* what kind of context this is */
 534     U8          blku_gimme;     /* is this block running in list context? */
 535     U8          blku_spare;     /* Padding to match with struct subst */
 536     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 537     COP *       blku_oldcop;    /* old curcop pointer */
 538     I32         blku_oldmarksp; /* mark stack index */
 539     I32         blku_oldscopesp;        /* scope stack index */
 540     PMOP *      blku_oldpm;     /* values of pattern match vars */
 541
 542     union {
 543         struct block_sub        blku_sub;
 544         struct block_format     blku_format;
 545         struct block_eval       blku_eval;
 546         struct block_loop       blku_loop;
 547         struct block_givwhen    blku_givwhen;
 548     } blk_u;
 549 };
 550 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 551 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 552 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 553 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 554 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 555 #define blk_gimme       cx_u.cx_blk.blku_gimme
 556 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 557 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 558 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 559 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 560 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 561
 562 /* Enter a block. */
 563 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 564         cx->cx_type             = t,                                    \
 565         cx->blk_oldsp           = sp - PL_stack_base,                   \
 566         cx->blk_oldcop          = PL_curcop,                            \
 567         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 568         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 569         cx->blk_oldpm           = PL_curpm,                             \
 570         cx->blk_gimme           = (U8)gimme;                            \
 571         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 572                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 573
 574 /* Exit a block (RETURN and LAST). */
 575 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 576         newsp            = PL_stack_base + cx->blk_oldsp,               \
 577         PL_curcop        = cx->blk_oldcop,                              \
 578         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 579         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 580         pm               = cx->blk_oldpm,                               \
 581         gimme            = cx->blk_gimme;                               \
 582         DEBUG_SCOPE("POPBLOCK");                                        \
 583         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 584                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 585
 586 /* Continue a block elsewhere (NEXT and REDO). */
 587 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 588         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 589         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 590         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 591         PL_curpm         = cx->blk_oldpm;                               \
 592         DEBUG_SCOPE("TOPBLOCK");
 593
 594 /* substitution context */
 595 struct subst {
 596     U16         sbu_type;       /* what kind of context this is */
 597     U8          sbu_once;       /* Actually both booleans, but U8 to matches */
 598     U8          sbu_rxtainted;  /* struct block */
 599     I32         sbu_iters;
 600     I32         sbu_maxiters;
 601     I32         sbu_rflags;
 602     I32         sbu_oldsave;
 603     char *      sbu_orig;
 604     SV *        sbu_dstr;
 605     SV *        sbu_targ;
 606     char *      sbu_s;
 607     char *      sbu_m;
 608     char *      sbu_strend;
 609     void *      sbu_rxres;
 610     REGEXP *    sbu_rx;
 611 };
 612 #define sb_iters        cx_u.cx_subst.sbu_iters
 613 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 614 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 615 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 616 #define sb_once         cx_u.cx_subst.sbu_once
 617 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 618 #define sb_orig         cx_u.cx_subst.sbu_orig
 619 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 620 #define sb_targ         cx_u.cx_subst.sbu_targ
 621 #define sb_s            cx_u.cx_subst.sbu_s
 622 #define sb_m            cx_u.cx_subst.sbu_m
 623 #define sb_strend       cx_u.cx_subst.sbu_strend
 624 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 625 #define sb_rx           cx_u.cx_subst.sbu_rx
 626
 627 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 628         cx->sb_iters            = iters,                                \
 629         cx->sb_maxiters         = maxiters,                             \
 630         cx->sb_rflags           = r_flags,                              \
 631         cx->sb_oldsave          = oldsave,                              \
 632         cx->sb_once             = once,                                 \
 633         cx->sb_rxtainted        = rxtainted,                            \
 634         cx->sb_orig             = orig,                                 \
 635         cx->sb_dstr             = dstr,                                 \
 636         cx->sb_targ             = targ,                                 \
 637         cx->sb_s                = s,                                    \
 638         cx->sb_m                = m,                                    \
 639         cx->sb_strend           = strend,                               \
 640         cx->sb_rxres            = NULL,                                 \
 641         cx->sb_rx               = rx,                                   \
 642         cx->cx_type             = CXt_SUBST;                            \
 643         rxres_save(&cx->sb_rxres, rx);                                  \
 644         (void)ReREFCNT_inc(rx)
 645
 646 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 647         rxres_free(&cx->sb_rxres);                                      \
 648         ReREFCNT_dec(cx->sb_rx)
 649
 650 struct context {
 651     union {
 652         struct block    cx_blk;
 653         struct subst    cx_subst;
 654     } cx_u;
 655 };
 656 #define cx_type cx_u.cx_subst.sbu_type
 657
 658 #define CXTYPEMASK      0xff
 659 #define CXt_NULL        0
 660 #define CXt_SUB         1
 661 #define CXt_EVAL        2
 662 #define CXt_LOOP        3
 663 #define CXt_SUBST       4
 664 #define CXt_BLOCK       5
 665 #define CXt_FORMAT      6
 666 #define CXt_GIVEN       7
 667 #define CXt_WHEN        8
 668
 669 /* private flags for CXt_SUB and CXt_NULL */
 670 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
 671                                            tear down context on exit). */
 672
 673 /* private flags for CXt_EVAL */
 674 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 675 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 676
 677 /* private flags for CXt_LOOP */
 678 #define CXp_FOREACH     0x00000200      /* a foreach loop */
 679 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
 680 #ifdef USE_ITHREADS
 681 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 682                                            has pad offset; if not set,
 683                                            iterdata holds GV* */
 684 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 685                          == (CXt_LOOP|CXp_PADVAR))
 686 #endif
 687
 688 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 689 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 690                          == CXp_MULTICALL)
 691 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 692                          == (CXt_EVAL|CXp_REAL))
 693 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 694                          == (CXt_EVAL|CXp_TRYBLOCK))
 695 #define CxFOREACH(c)    (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH))      \
 696                          == (CXt_LOOP|CXp_FOREACH))
 697 #define CxFOREACHDEF(c) (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH|CXp_FOR_DEF))\
 698                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 699
 700 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 701
 702 /*
 703 =head1 "Gimme" Values
 704 */
 705
 706 /*
 707 =for apidoc AmU||G_SCALAR
 708 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 709 L<perlcall>.
 710
 711 =for apidoc AmU||G_ARRAY
 712 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 713 L<perlcall>.
 714
 715 =for apidoc AmU||G_VOID
 716 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 717
 718 =for apidoc AmU||G_DISCARD
 719 Indicates that arguments returned from a callback should be discarded.  See
 720 L<perlcall>.
 721
 722 =for apidoc AmU||G_EVAL
 723
 724 Used to force a Perl C<eval> wrapper around a callback.  See
 725 L<perlcall>.
 726
 727 =for apidoc AmU||G_NOARGS
 728
 729 Indicates that no arguments are being sent to a callback.  See
 730 L<perlcall>.
 731
 732 =cut
 733 */
 734
 735 #define G_SCALAR        0
 736 #define G_ARRAY         1
 737 #define G_VOID          128     /* skip this bit when adding flags below */
 738
 739 /* extra flags for Perl_call_* routines */
 740 #define G_DISCARD       2       /* Call FREETMPS.
 741                                    Don't change this without consulting the
 742                                    hash actions codes defined in hv.h */
 743 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 744 #define G_NOARGS        8       /* Don't construct a @_ array. */
 745 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 746 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 747 #define G_METHOD       64       /* Calling method. */
 748 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 749                                    fold_constants. */
 750
 751 /* flag bits for PL_in_eval */
 752 #define EVAL_NULL       0       /* not in an eval */
 753 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 754 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 755 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 756 #define EVAL_INREQUIRE  8       /* The code is being required. */
 757
 758 /* Support for switching (stack and block) contexts.
 759  * This ensures magic doesn't invalidate local stack and cx pointers.
 760  */
 761
 762 #define PERLSI_UNKNOWN          -1
 763 #define PERLSI_UNDEF            0
 764 #define PERLSI_MAIN             1
 765 #define PERLSI_MAGIC            2
 766 #define PERLSI_SORT             3
 767 #define PERLSI_SIGNAL           4
 768 #define PERLSI_OVERLOAD         5
 769 #define PERLSI_DESTROY          6
 770 #define PERLSI_WARNHOOK         7
 771 #define PERLSI_DIEHOOK          8
 772 #define PERLSI_REQUIRE          9
 773
 774 struct stackinfo {
 775     AV *                si_stack;       /* stack for current runlevel */
 776     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 777     struct stackinfo *  si_prev;
 778     struct stackinfo *  si_next;
 779     I32                 si_cxix;        /* current context index */
 780     I32                 si_cxmax;       /* maximum allocated index */
 781     I32                 si_type;        /* type of runlevel */
 782     I32                 si_markoff;     /* offset where markstack begins for us.
 783                                          * currently used only with DEBUGGING,
 784                                          * but not #ifdef-ed for bincompat */
 785 };
 786
 787 typedef struct stackinfo PERL_SI;
 788
 789 #define cxstack         (PL_curstackinfo->si_cxstack)
 790 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 791 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 792
 793 #ifdef DEBUGGING
 794 #  define       SET_MARK_OFFSET \
 795     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 796 #else
 797 #  define       SET_MARK_OFFSET NOOP
 798 #endif
 799
 800 #define PUSHSTACKi(type) \
 801     STMT_START {                                                        \
 802         PERL_SI *next = PL_curstackinfo->si_next;                       \
 803         if (!next) {                                                    \
 804             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 805             next->si_prev = PL_curstackinfo;                            \
 806             PL_curstackinfo->si_next = next;                            \
 807         }                                                               \
 808         next->si_type = type;                                           \
 809         next->si_cxix = -1;                                             \
 810         AvFILLp(next->si_stack) = 0;                                    \
 811         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 812         PL_curstackinfo = next;                                         \
 813         SET_MARK_OFFSET;                                                \
 814     } STMT_END
 815
 816 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 817
 818 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 819  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 820 #define POPSTACK \
 821     STMT_START {                                                        \
 822         dSP;                                                            \
 823         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 824         if (!prev) {                                                    \
 825             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 826             my_exit(1);                                                 \
 827         }                                                               \
 828         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 829         /* don't free prev here, free them all at the END{} */          \
 830         PL_curstackinfo = prev;                                         \
 831     } STMT_END
 832
 833 #define POPSTACK_TO(s) \
 834     STMT_START {                                                        \
 835         while (PL_curstack != s) {                                      \
 836             dounwind(-1);                                               \
 837             POPSTACK;                                                   \
 838         }                                                               \
 839     } STMT_END
 840
 841 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 842 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 843
 844 /*
 845 =head1 Multicall Functions
 846
 847 =for apidoc Ams||dMULTICALL
 848 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 849
 850 =for apidoc Ams||PUSH_MULTICALL
 851 Opening bracket for a lightweight callback.
 852 See L<perlcall/Lightweight Callbacks>.
 853
 854 =for apidoc Ams||MULTICALL
 855 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 856
 857 =for apidoc Ams||POP_MULTICALL
 858 Closing bracket for a lightweight callback.
 859 See L<perlcall/Lightweight Callbacks>.
 860
 861 =cut
 862 */
 863
 864 #define dMULTICALL \
 865     SV **newsp;                 /* set by POPBLOCK */                   \
 866     PERL_CONTEXT *cx;                                                   \
 867     CV *multicall_cv;                                                   \
 868     OP *multicall_cop;                                                  \
 869     bool multicall_oldcatch;                                            \
 870     U8 hasargs = 0              /* used by PUSHSUB */
 871
 872 #define PUSH_MULTICALL(the_cv) \
 873     STMT_START {                                                        \
 874         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 875         CV * const cv = _nOnclAshIngNamE_;                              \
 876         AV * const padlist = CvPADLIST(cv);                             \
 877         ENTER;                                                          \
 878         multicall_oldcatch = CATCH_GET;                                 \
 879         SAVETMPS; SAVEVPTR(PL_op);                                      \
 880         CATCH_SET(TRUE);                                                \
 881         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 882         PUSHSUB(cx);                                                    \
 883         if (++CvDEPTH(cv) >= 2) {                                       \
 884             PERL_STACK_OVERFLOW_CHECK();                                \
 885             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 886         }                                                               \
 887         SAVECOMPPAD();                                                  \
 888         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 889         multicall_cv = cv;                                              \
 890         multicall_cop = CvSTART(cv);                                    \
 891     } STMT_END
 892
 893 #define MULTICALL \
 894     STMT_START {                                                        \
 895         PL_op = multicall_cop;                                          \
 896         CALLRUNOPS(aTHX);                                               \
 897     } STMT_END
 898
 899 #define POP_MULTICALL \
 900     STMT_START {                                                        \
 901         LEAVESUB(multicall_cv);                                         \
 902         CvDEPTH(multicall_cv)--;                                        \
 903         POPBLOCK(cx,PL_curpm);                                          \
 904         CATCH_SET(multicall_oldcatch);                                  \
 905         LEAVE;                                                          \
 906     } STMT_END
 907
 908 /*
 909  * Local variables:
 910  * c-indentation-style: bsd
 911  * c-basic-offset: 4
 912  * indent-tabs-mode: t
 913  * End:
 914  *
 915  * ex: set ts=8 sts=4 sw=4 noet:
 916  */