cop.h

   1 /*    cop.h
   2  *
   3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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 two ops OP_NEXTSTATE and OP_DBSTATE,
  10  * 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 PL_start_env initialized when perl starts, and
  18  * PL_top_env points to this initially, so PL_top_env should always be
  19  * non-null.
  20  *
  21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
  22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
  23  * null to ensure this).
  24  *
  25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
  26  * establish a local jmpenv to handle exception traps.  Care must be taken
  27  * to restore the previous value of je_mustcatch before exiting the
  28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
  29  * GSAR 97-03-27
  30  */
  31
  32 struct jmpenv {
  33     struct jmpenv *     je_prev;
  34     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
  35     int                 je_ret;         /* last exception thrown */
  36     bool                je_mustcatch;   /* need to call longjmp()? */
  37 };
  38
  39 typedef struct jmpenv JMPENV;
  40
  41 #ifdef OP_IN_REGISTER
  42 #define OP_REG_TO_MEM   PL_opsave = op
  43 #define OP_MEM_TO_REG   op = PL_opsave
  44 #else
  45 #define OP_REG_TO_MEM   NOOP
  46 #define OP_MEM_TO_REG   NOOP
  47 #endif
  48
  49 /*
  50  * How to build the first jmpenv.
  51  *
  52  * top_env needs to be non-zero. It points to an area
  53  * in which longjmp() stuff is stored, as C callstack
  54  * info there at least is thread specific this has to
  55  * be per-thread. Otherwise a 'die' in a thread gives
  56  * that thread the C stack of last thread to do an eval {}!
  57  */
  58
  59 #define JMPENV_BOOTSTRAP \
  60     STMT_START {                                \
  61         Zero(&PL_start_env, 1, JMPENV);         \
  62         PL_start_env.je_ret = -1;               \
  63         PL_start_env.je_mustcatch = TRUE;       \
  64         PL_top_env = &PL_start_env;             \
  65     } STMT_END
  66
  67 /*
  68  *   PERL_FLEXIBLE_EXCEPTIONS
  69  *
  70  * All the flexible exceptions code has been removed.
  71  * See the following threads for details:
  72  *
  73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
  74  *
  75  * Joshua's original patches (which weren't applied) and discussion:
  76  *
  77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
  78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
  79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
  80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
  81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
  82  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
  83  *
  84  * Chip's reworked patch and discussion:
  85  *
  86  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
  87  *
  88  * The flaw in these patches (which went unnoticed at the time) was
  89  * that they moved some code that could potentially die() out of the
  90  * region protected by the setjmp()s.  This caused exceptions within
  91  * END blocks and such to not be handled by the correct setjmp().
  92  *
  93  * The original patches that introduces flexible exceptions were:
  94  *
  95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
  96  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
  97  */
  98
  99 #define dJMPENV         JMPENV cur_env
 100
 101 #define JMPENV_PUSH(v) \
 102     STMT_START {                                                        \
 103         DEBUG_l({                                                       \
 104             int i = 0; JMPENV *p = PL_top_env;                          \
 105             while (p) { i++; p = p->je_prev; }                          \
 106             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
 107                          i,  __FILE__, __LINE__);})                     \
 108         cur_env.je_prev = PL_top_env;                                   \
 109         OP_REG_TO_MEM;                                                  \
 110         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
 111         OP_MEM_TO_REG;                                                  \
 112         PL_top_env = &cur_env;                                          \
 113         cur_env.je_mustcatch = FALSE;                                   \
 114         (v) = cur_env.je_ret;                                           \
 115     } STMT_END
 116
 117 #define JMPENV_POP \
 118     STMT_START {                                                        \
 119         DEBUG_l({                                                       \
 120             int i = -1; JMPENV *p = PL_top_env;                         \
 121             while (p) { i++; p = p->je_prev; }                          \
 122             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
 123                          i, __FILE__, __LINE__);})                      \
 124         assert(PL_top_env == &cur_env);                                 \
 125         PL_top_env = cur_env.je_prev;                                   \
 126     } STMT_END
 127
 128 #define JMPENV_JUMP(v) \
 129     STMT_START {                                                \
 130         DEBUG_l({                                               \
 131             int i = -1; JMPENV *p = PL_top_env;                 \
 132             while (p) { i++; p = p->je_prev; }                  \
 133             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
 134                          (int)v, i, __FILE__, __LINE__);})      \
 135         OP_REG_TO_MEM;                                          \
 136         if (PL_top_env->je_prev)                                \
 137             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
 138         if ((v) == 2)                                           \
 139             PerlProc_exit(STATUS_EXIT);                         \
 140         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
 141         PerlProc_exit(1);                                       \
 142     } STMT_END
 143
 144 #define CATCH_GET               (PL_top_env->je_mustcatch)
 145 #define CATCH_SET(v) \
 146     STMT_START {                                                        \
 147         DEBUG_l(                                                        \
 148             Perl_deb(aTHX_                                              \
 149                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
 150                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
 151                  __FILE__, __LINE__);)                                  \
 152         PL_top_env->je_mustcatch = (v);                                 \
 153     } STMT_END
 154
 155
 156 #include "mydtrace.h"
 157
 158 struct cop {
 159     BASEOP
 160     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
 161        an exact multiple of 8 bytes to save structure padding.  */
 162     line_t      cop_line;       /* line # of this command */
 163     /* label for this construct is now stored in cop_hints_hash */
 164 #ifdef USE_ITHREADS
 165     char *      cop_stashpv;    /* package line was compiled in */
 166     char *      cop_file;       /* file name the following line # is from */
 167 #else
 168     HV *        cop_stash;      /* package line was compiled in */
 169     GV *        cop_filegv;     /* file the following line # is from */
 170 #endif
 171     U32         cop_hints;      /* hints bits from pragmata */
 172     U32         cop_seq;        /* parse sequence number */
 173     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 174     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 175     /* compile time state of %^H.  See the comment in op.c for how this is
 176        used to recreate a hash to return from caller.  */
 177     struct refcounted_he * cop_hints_hash;
 178 };
 179
 180 #ifdef USE_ITHREADS
 181 #  define CopFILE(c)            ((c)->cop_file)
 182 #  define CopFILEGV(c)          (CopFILE(c) \
 183                                  ? gv_fetchfile(CopFILE(c)) : NULL)
 184
 185 #  ifdef NETWARE
 186 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
 187 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
 188 #  else
 189 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
 190 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
 191 #  endif
 192
 193 #  define CopFILESV(c)          (CopFILE(c) \
 194                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 195 #  define CopFILEAV(c)          (CopFILE(c) \
 196                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
 197 #  ifdef DEBUGGING
 198 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
 199                                    GvAV(gv_fetchfile(CopFILE(c))))
 200 #  else
 201 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
 202 #  endif
 203 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
 204
 205 #  ifdef NETWARE
 206 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
 207 #  else
 208 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
 209 #  endif
 210
 211 #  define CopSTASH(c)           (CopSTASHPV(c) \
 212                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
 213 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
 214 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
 215 #  ifdef NETWARE
 216 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
 217 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
 218 #  else
 219 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
 220 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
 221 #  endif
 222 #else
 223 #  define CopFILEGV(c)          ((c)->cop_filegv)
 224 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 225 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
 226 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
 227 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
 228 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
 229 #  ifdef DEBUGGING
 230 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
 231 #  else
 232 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
 233 # endif
 234 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
 235                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
 236 #  define CopSTASH(c)           ((c)->cop_stash)
 237 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
 238 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
 239    /* cop_stash is not refcounted */
 240 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 241 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
 242 #  define CopSTASH_free(c)
 243 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
 244
 245 #endif /* USE_ITHREADS */
 246 #define CopLABEL(c)  Perl_fetch_cop_label(aTHX_ (c), NULL, NULL)
 247 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
 248
 249 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
 250 #define CopLINE(c)              ((c)->cop_line)
 251 #define CopLINE_inc(c)          (++CopLINE(c))
 252 #define CopLINE_dec(c)          (--CopLINE(c))
 253 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
 254
 255 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
 256 #define OutCopFILE(c) CopFILE(c)
 257
 258 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
 259    HINT_ARYBASE is set to indicate this.
 260    Setting it is ineficient due to the need to create 2 mortal SVs, but as
 261    using $[ is highly discouraged, no sane Perl code will be using it.  */
 262 #define CopARYBASE_get(c)       \
 263         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
 264          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
 265                                          "$[", 2, 0, 0))                \
 266          : 0)
 267 #define CopARYBASE_set(c, b) STMT_START { \
 268         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
 269             (c)->cop_hints |= HINT_ARYBASE;                             \
 270             if ((c) == &PL_compiling) {                                 \
 271                 SV *val = newSViv(b);                                   \
 272                 (void)hv_stores(GvHV(PL_hintgv), "$[", val);            \
 273                 mg_set(val);                                            \
 274                 PL_hints |= HINT_ARYBASE;                               \
 275             } else {                                                    \
 276                 (c)->cop_hints_hash                                     \
 277                    = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,  \
 278                                         newSVpvs_flags("$[", SVs_TEMP), \
 279                                         sv_2mortal(newSViv(b)));        \
 280             }                                                           \
 281         }                                                               \
 282     } STMT_END
 283
 284 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
 285 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
 286 #define CopHINTS_set(c, h)      STMT_START {                            \
 287                                     (c)->cop_hints = (h);               \
 288                                 } STMT_END
 289
 290 /*
 291  * Here we have some enormously heavy (or at least ponderous) wizardry.
 292  */
 293
 294 /* subroutine context */
 295 struct block_sub {
 296     OP *        retop;  /* op to execute on exit from sub */
 297     /* Above here is the same for sub, format and eval.  */
 298     CV *        cv;
 299     /* Above here is the same for sub and format.  */
 300     AV *        savearray;
 301     AV *        argarray;
 302     I32         olddepth;
 303     PAD         *oldcomppad;
 304 };
 305
 306
 307 /* format context */
 308 struct block_format {
 309     OP *        retop;  /* op to execute on exit from sub */
 310     /* Above here is the same for sub, format and eval.  */
 311     CV *        cv;
 312     /* Above here is the same for sub and format.  */
 313     GV *        gv;
 314     GV *        dfoutgv;
 315 };
 316
 317 /* base for the next two macros. Don't use directly.
 318  * Note that the refcnt of the cv is incremented twice;  The CX one is
 319  * decremented by LEAVESUB, the other by LEAVE. */
 320
 321 #define PUSHSUB_BASE(cx)                                                \
 322         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
 323                 CopFILE((const COP *)CvSTART(cv)),                      \
 324                 CopLINE((const COP *)CvSTART(cv)));                     \
 325                                                                         \
 326         cx->blk_sub.cv = cv;                                            \
 327         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 328         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
 329         cx->blk_sub.retop = NULL;                                       \
 330         if (!CvDEPTH(cv)) {                                             \
 331             SvREFCNT_inc_simple_void_NN(cv);                            \
 332             SvREFCNT_inc_simple_void_NN(cv);                            \
 333             SAVEFREESV(cv);                                             \
 334         }
 335
 336
 337 #define PUSHSUB(cx)                                                     \
 338         PUSHSUB_BASE(cx)                                                \
 339         cx->blk_u16 = PL_op->op_private &                               \
 340                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 341
 342 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 343 #define PUSHSUB_DB(cx)                                                  \
 344         PUSHSUB_BASE(cx)                                                \
 345         cx->blk_u16 = 0;
 346
 347
 348 #define PUSHFORMAT(cx, retop)                                           \
 349         cx->blk_format.cv = cv;                                         \
 350         cx->blk_format.gv = gv;                                         \
 351         cx->blk_format.retop = (retop);                                 \
 352         cx->blk_format.dfoutgv = PL_defoutgv;                           \
 353         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
 354
 355 #define POP_SAVEARRAY()                                         \
 356     STMT_START {                                                        \
 357         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 358         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 359     } STMT_END
 360
 361 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 362  * leave any (a fast av_clear(ary), basically) */
 363 #define CLEAR_ARGARRAY(ary) \
 364     STMT_START {                                                        \
 365         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 366         AvARRAY(ary) = AvALLOC(ary);                                    \
 367         AvFILLp(ary) = -1;                                              \
 368     } STMT_END
 369
 370 #define POPSUB(cx,sv)                                                   \
 371     STMT_START {                                                        \
 372         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
 373                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
 374                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)));     \
 375                                                                         \
 376         if (CxHASARGS(cx)) {                                            \
 377             POP_SAVEARRAY();                                            \
 378             /* abandon @_ if it got reified */                          \
 379             if (AvREAL(cx->blk_sub.argarray)) {                         \
 380                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
 381                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 382                 cx->blk_sub.argarray = newAV();                         \
 383                 av_extend(cx->blk_sub.argarray, fill);                  \
 384                 AvREIFY_only(cx->blk_sub.argarray);                     \
 385                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
 386             }                                                           \
 387             else {                                                      \
 388                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 389             }                                                           \
 390         }                                                               \
 391         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
 392         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
 393             sv = NULL;                                          \
 394     } STMT_END
 395
 396 #define LEAVESUB(sv)                                                    \
 397     STMT_START {                                                        \
 398         if (sv)                                                         \
 399             SvREFCNT_dec(sv);                                           \
 400     } STMT_END
 401
 402 #define POPFORMAT(cx)                                                   \
 403         setdefout(cx->blk_format.dfoutgv);                              \
 404         SvREFCNT_dec(cx->blk_format.dfoutgv);
 405
 406 /* eval context */
 407 struct block_eval {
 408     OP *        retop;  /* op to execute on exit from eval */
 409     /* Above here is the same for sub, format and eval.  */
 410     SV *        old_namesv;
 411     OP *        old_eval_root;
 412     SV *        cur_text;
 413     CV *        cv;
 414     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 415 };
 416
 417 /* If we ever need more than 512 op types, change the shift from 7.
 418    blku_gimme is actually also only 2 bits, so could be merged with something.
 419 */
 420
 421 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
 422 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
 423
 424 #define PUSHEVAL(cx,n)                                                  \
 425     STMT_START {                                                        \
 426         assert(!(PL_in_eval & ~0x7F));                                  \
 427         assert(!(PL_op->op_type & ~0x1FF));                             \
 428         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
 429         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 430         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 431         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
 432         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 433         cx->blk_eval.retop = NULL;                                      \
 434         cx->blk_eval.cur_top_env = PL_top_env;                          \
 435     } STMT_END
 436
 437 #define POPEVAL(cx)                                                     \
 438     STMT_START {                                                        \
 439         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
 440         optype = CxOLD_OP_TYPE(cx);                                     \
 441         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 442         if (cx->blk_eval.old_namesv)                                    \
 443             sv_2mortal(cx->blk_eval.old_namesv);                        \
 444     } STMT_END
 445
 446 /* loop context */
 447 struct block_loop {
 448     I32         resetsp;
 449     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
 450     union {     /* different ways of locating the iteration variable */
 451         SV      **svp;
 452         GV      *gv;
 453         PAD     *oldcomppad; /* only used in ITHREADS */
 454     } itervar_u;
 455     union {
 456         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
 457             AV * ary; /* use the stack if this is NULL */
 458             IV ix;
 459         } ary;
 460         struct { /* valid if type is LOOP_LAZYIV */
 461             IV cur;
 462             IV end;
 463         } lazyiv;
 464         struct { /* valid if type if LOOP_LAZYSV */
 465             SV * cur;
 466             SV * end; /* maxiumum value (or minimum in reverse) */
 467         } lazysv;
 468     } state_u;
 469 };
 470
 471 #ifdef USE_ITHREADS
 472 #  define CxITERVAR_PADSV(c) \
 473         &CX_CURPAD_SV( (c)->blk_loop.itervar_u, (c)->blk_loop.my_op->op_targ)
 474 #else
 475 #  define CxITERVAR_PADSV(c) ((c)->blk_loop.itervar_u.svp)
 476 #endif
 477
 478 #define CxITERVAR(c)                                                    \
 479         ((c)->blk_loop.itervar_u.oldcomppad                             \
 480          ? (CxPADLOOP(c)                                                \
 481             ? CxITERVAR_PADSV(c)                                        \
 482             : &GvSV((c)->blk_loop.itervar_u.gv))                        \
 483          : (SV**)NULL)
 484
 485 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
 486 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
 487 #define CxLVAL(c)       (0 + (c)->blk_u16)
 488
 489 #define PUSHLOOP_PLAIN(cx, s)                                           \
 490         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 491         cx->blk_loop.my_op = cLOOP;                                     \
 492         cx->blk_loop.state_u.ary.ary = NULL;                            \
 493         cx->blk_loop.state_u.ary.ix = 0;                                \
 494         cx->blk_loop.itervar_u.svp = NULL;
 495
 496 #define PUSHLOOP_FOR(cx, ivar, s)                                       \
 497         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 498         cx->blk_loop.my_op = cLOOP;                                     \
 499         cx->blk_loop.state_u.ary.ary = NULL;                            \
 500         cx->blk_loop.state_u.ary.ix = 0;                                \
 501         cx->blk_loop.itervar_u.svp = (SV**)(ivar);
 502
 503 #define POPLOOP(cx)                                                     \
 504         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
 505             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
 506             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
 507         }                                                               \
 508         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
 509             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
 510
 511 /* given/when context */
 512 struct block_givwhen {
 513         OP *leave_op;
 514 };
 515
 516 #define PUSHGIVEN(cx)                                                   \
 517         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 518
 519 #define PUSHWHEN PUSHGIVEN
 520
 521 /* context common to subroutines, evals and loops */
 522 struct block {
 523     U8          blku_type;      /* what kind of context this is */
 524     U8          blku_gimme;     /* is this block running in list context? */
 525     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
 526     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 527     COP *       blku_oldcop;    /* old curcop pointer */
 528     I32         blku_oldmarksp; /* mark stack index */
 529     I32         blku_oldscopesp;        /* scope stack index */
 530     PMOP *      blku_oldpm;     /* values of pattern match vars */
 531
 532     union {
 533         struct block_sub        blku_sub;
 534         struct block_format     blku_format;
 535         struct block_eval       blku_eval;
 536         struct block_loop       blku_loop;
 537         struct block_givwhen    blku_givwhen;
 538     } blk_u;
 539 };
 540 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 541 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 542 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 543 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 544 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 545 #define blk_gimme       cx_u.cx_blk.blku_gimme
 546 #define blk_u16         cx_u.cx_blk.blku_u16
 547 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 548 #define blk_format      cx_u.cx_blk.blk_u.blku_format
 549 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 550 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 551 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 552
 553 #define DEBUG_CX(action)                                                \
 554     DEBUG_l(                                                            \
 555         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
 556                     (long)cxstack_ix,                                   \
 557                     action,                                             \
 558                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
 559                     (long)PL_scopestack_ix,                             \
 560                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
 561                     __FILE__, __LINE__));
 562
 563 /* Enter a block. */
 564 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 565         cx->cx_type             = t,                                    \
 566         cx->blk_oldsp           = sp - PL_stack_base,                   \
 567         cx->blk_oldcop          = PL_curcop,                            \
 568         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 569         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 570         cx->blk_oldpm           = PL_curpm,                             \
 571         cx->blk_gimme           = (U8)gimme;                            \
 572         DEBUG_CX("PUSH");
 573
 574 /* Exit a block (RETURN and LAST). */
 575 #define POPBLOCK(cx,pm)                                                 \
 576         DEBUG_CX("POP");                                                \
 577         cx = &cxstack[cxstack_ix--],                                    \
 578         newsp            = PL_stack_base + cx->blk_oldsp,               \
 579         PL_curcop        = cx->blk_oldcop,                              \
 580         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 581         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 582         pm               = cx->blk_oldpm,                               \
 583         gimme            = cx->blk_gimme;
 584
 585 /* Continue a block elsewhere (NEXT and REDO). */
 586 #define TOPBLOCK(cx)                                                    \
 587         DEBUG_CX("TOP");                                                \
 588         cx  = &cxstack[cxstack_ix],                                     \
 589         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 590         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 591         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 592         PL_curpm         = cx->blk_oldpm;
 593
 594 /* substitution context */
 595 struct subst {
 596     U8          sbu_type;       /* what kind of context this is */
 597     U8          sbu_rflags;
 598     U16         sbu_rxtainted;  /* matches struct block */
 599     I32         sbu_iters;
 600     I32         sbu_maxiters;
 601     I32         sbu_oldsave;
 602     char *      sbu_orig;
 603     SV *        sbu_dstr;
 604     SV *        sbu_targ;
 605     char *      sbu_s;
 606     char *      sbu_m;
 607     char *      sbu_strend;
 608     void *      sbu_rxres;
 609     REGEXP *    sbu_rx;
 610 };
 611 #define sb_iters        cx_u.cx_subst.sbu_iters
 612 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 613 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 614 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 615 #define sb_once         cx_u.cx_subst.sbu_once
 616 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 617 #define sb_orig         cx_u.cx_subst.sbu_orig
 618 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 619 #define sb_targ         cx_u.cx_subst.sbu_targ
 620 #define sb_s            cx_u.cx_subst.sbu_s
 621 #define sb_m            cx_u.cx_subst.sbu_m
 622 #define sb_strend       cx_u.cx_subst.sbu_strend
 623 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 624 #define sb_rx           cx_u.cx_subst.sbu_rx
 625
 626 #ifdef PERL_CORE
 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_rxtainted        = rxtainted,                            \
 633         cx->sb_orig             = orig,                                 \
 634         cx->sb_dstr             = dstr,                                 \
 635         cx->sb_targ             = targ,                                 \
 636         cx->sb_s                = s,                                    \
 637         cx->sb_m                = m,                                    \
 638         cx->sb_strend           = strend,                               \
 639         cx->sb_rxres            = NULL,                                 \
 640         cx->sb_rx               = rx,                                   \
 641         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
 642         rxres_save(&cx->sb_rxres, rx);                                  \
 643         (void)ReREFCNT_inc(rx)
 644
 645 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
 646         rxres_free(&cx->sb_rxres);                                      \
 647         ReREFCNT_dec(cx->sb_rx)
 648 #endif
 649
 650 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
 651
 652 struct context {
 653     union {
 654         struct block    cx_blk;
 655         struct subst    cx_subst;
 656     } cx_u;
 657 };
 658 #define cx_type cx_u.cx_subst.sbu_type
 659
 660 /* If you re-order these, there is also an array of uppercase names in perl.h
 661    and a static array of context names in pp_ctl.c  */
 662 #define CXTYPEMASK      0xf
 663 #define CXt_NULL        0
 664 #define CXt_WHEN        1
 665 #define CXt_BLOCK       2
 666 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
 667    jump table in pp_ctl.c
 668    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
 669 */
 670 #define CXt_GIVEN       3
 671 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
 672 #define CXt_LOOP_FOR    4
 673 #define CXt_LOOP_PLAIN  5
 674 #define CXt_LOOP_LAZYSV 6
 675 #define CXt_LOOP_LAZYIV 7
 676 #define CXt_SUB         8
 677 #define CXt_FORMAT      9
 678 #define CXt_EVAL       10
 679 #define CXt_SUBST      11
 680 /* SUBST doesn't feature in all switch statements.  */
 681
 682 /* private flags for CXt_SUB and CXt_NULL
 683    However, this is checked in many places which do not check the type, so
 684    this bit needs to be kept clear for most everything else. For reasons I
 685    haven't investigated, it can coexist with CXp_FOR_DEF */
 686 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
 687                                    tear down context on exit). */
 688
 689 /* private flags for CXt_SUB and CXt_FORMAT */
 690 #define CXp_HASARGS     0x20
 691
 692 /* private flags for CXt_EVAL */
 693 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
 694 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
 695
 696 /* private flags for CXt_LOOP */
 697 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
 698 #define CxPADLOOP(c)    ((c)->blk_loop.my_op->op_targ)
 699
 700 /* private flags for CXt_SUBST */
 701 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
 702
 703 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 704 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
 705 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 706                          == CXp_MULTICALL)
 707 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
 708                          == (CXt_EVAL|CXp_REAL))
 709 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
 710                          == (CXt_EVAL|CXp_TRYBLOCK))
 711 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
 712 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
 713                          && ((c)->cx_type & CXp_FOR_DEF))
 714
 715 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 716
 717 /*
 718 =head1 "Gimme" Values
 719 */
 720
 721 /*
 722 =for apidoc AmU||G_SCALAR
 723 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 724 L<perlcall>.
 725
 726 =for apidoc AmU||G_ARRAY
 727 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 728 L<perlcall>.
 729
 730 =for apidoc AmU||G_VOID
 731 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 732
 733 =for apidoc AmU||G_DISCARD
 734 Indicates that arguments returned from a callback should be discarded.  See
 735 L<perlcall>.
 736
 737 =for apidoc AmU||G_EVAL
 738
 739 Used to force a Perl C<eval> wrapper around a callback.  See
 740 L<perlcall>.
 741
 742 =for apidoc AmU||G_NOARGS
 743
 744 Indicates that no arguments are being sent to a callback.  See
 745 L<perlcall>.
 746
 747 =cut
 748 */
 749
 750 #define G_SCALAR        2
 751 #define G_ARRAY         3
 752 #define G_VOID          1
 753 #define G_WANT          3
 754
 755 /* extra flags for Perl_call_* routines */
 756 #define G_DISCARD       4       /* Call FREETMPS.
 757                                    Don't change this without consulting the
 758                                    hash actions codes defined in hv.h */
 759 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
 760 #define G_NOARGS       16       /* Don't construct a @_ array. */
 761 #define G_KEEPERR      32       /* Warn for errors, don't overwrite $@ */
 762 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
 763 #define G_METHOD      128       /* Calling method. */
 764 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
 765                                    fold_constants. */
 766 #define G_UNDEF_FILL  512       /* Fill the stack with &PL_sv_undef
 767                                    A special case for UNSHIFT in
 768                                    Perl_magic_methcall().  */
 769
 770 /* flag bits for PL_in_eval */
 771 #define EVAL_NULL       0       /* not in an eval */
 772 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 773 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 774 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 775 #define EVAL_INREQUIRE  8       /* The code is being required. */
 776
 777 /* Support for switching (stack and block) contexts.
 778  * This ensures magic doesn't invalidate local stack and cx pointers.
 779  */
 780
 781 #define PERLSI_UNKNOWN          -1
 782 #define PERLSI_UNDEF            0
 783 #define PERLSI_MAIN             1
 784 #define PERLSI_MAGIC            2
 785 #define PERLSI_SORT             3
 786 #define PERLSI_SIGNAL           4
 787 #define PERLSI_OVERLOAD         5
 788 #define PERLSI_DESTROY          6
 789 #define PERLSI_WARNHOOK         7
 790 #define PERLSI_DIEHOOK          8
 791 #define PERLSI_REQUIRE          9
 792
 793 struct stackinfo {
 794     AV *                si_stack;       /* stack for current runlevel */
 795     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 796     struct stackinfo *  si_prev;
 797     struct stackinfo *  si_next;
 798     I32                 si_cxix;        /* current context index */
 799     I32                 si_cxmax;       /* maximum allocated index */
 800     I32                 si_type;        /* type of runlevel */
 801     I32                 si_markoff;     /* offset where markstack begins for us.
 802                                          * currently used only with DEBUGGING,
 803                                          * but not #ifdef-ed for bincompat */
 804 };
 805
 806 typedef struct stackinfo PERL_SI;
 807
 808 #define cxstack         (PL_curstackinfo->si_cxstack)
 809 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 810 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 811
 812 #ifdef DEBUGGING
 813 #  define       SET_MARK_OFFSET \
 814     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 815 #else
 816 #  define       SET_MARK_OFFSET NOOP
 817 #endif
 818
 819 #define PUSHSTACKi(type) \
 820     STMT_START {                                                        \
 821         PERL_SI *next = PL_curstackinfo->si_next;                       \
 822         DEBUG_l({                                                       \
 823             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
 824             while (p) { i++; p = p->si_prev; }                          \
 825             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
 826                          i, __FILE__, __LINE__);})                      \
 827         if (!next) {                                                    \
 828             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 829             next->si_prev = PL_curstackinfo;                            \
 830             PL_curstackinfo->si_next = next;                            \
 831         }                                                               \
 832         next->si_type = type;                                           \
 833         next->si_cxix = -1;                                             \
 834         AvFILLp(next->si_stack) = 0;                                    \
 835         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 836         PL_curstackinfo = next;                                         \
 837         SET_MARK_OFFSET;                                                \
 838     } STMT_END
 839
 840 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 841
 842 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 843  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 844 #define POPSTACK \
 845     STMT_START {                                                        \
 846         dSP;                                                            \
 847         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 848         DEBUG_l({                                                       \
 849             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
 850             while (p) { i++; p = p->si_prev; }                          \
 851             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
 852                          i, __FILE__, __LINE__);})                      \
 853         if (!prev) {                                                    \
 854             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 855             my_exit(1);                                                 \
 856         }                                                               \
 857         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 858         /* don't free prev here, free them all at the END{} */          \
 859         PL_curstackinfo = prev;                                         \
 860     } STMT_END
 861
 862 #define POPSTACK_TO(s) \
 863     STMT_START {                                                        \
 864         while (PL_curstack != s) {                                      \
 865             dounwind(-1);                                               \
 866             POPSTACK;                                                   \
 867         }                                                               \
 868     } STMT_END
 869
 870 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 871 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 872
 873 /*
 874 =head1 Multicall Functions
 875
 876 =for apidoc Ams||dMULTICALL
 877 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 878
 879 =for apidoc Ams||PUSH_MULTICALL
 880 Opening bracket for a lightweight callback.
 881 See L<perlcall/Lightweight Callbacks>.
 882
 883 =for apidoc Ams||MULTICALL
 884 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 885
 886 =for apidoc Ams||POP_MULTICALL
 887 Closing bracket for a lightweight callback.
 888 See L<perlcall/Lightweight Callbacks>.
 889
 890 =cut
 891 */
 892
 893 #define dMULTICALL \
 894     SV **newsp;                 /* set by POPBLOCK */                   \
 895     PERL_CONTEXT *cx;                                                   \
 896     CV *multicall_cv;                                                   \
 897     OP *multicall_cop;                                                  \
 898     bool multicall_oldcatch;                                            \
 899     U8 hasargs = 0              /* used by PUSHSUB */
 900
 901 #define PUSH_MULTICALL(the_cv) \
 902     STMT_START {                                                        \
 903         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 904         CV * const cv = _nOnclAshIngNamE_;                              \
 905         AV * const padlist = CvPADLIST(cv);                             \
 906         ENTER;                                                          \
 907         multicall_oldcatch = CATCH_GET;                                 \
 908         SAVETMPS; SAVEVPTR(PL_op);                                      \
 909         CATCH_SET(TRUE);                                                \
 910         PUSHSTACKi(PERLSI_SORT);                                        \
 911         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 912         PUSHSUB(cx);                                                    \
 913         if (++CvDEPTH(cv) >= 2) {                                       \
 914             PERL_STACK_OVERFLOW_CHECK();                                \
 915             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 916         }                                                               \
 917         SAVECOMPPAD();                                                  \
 918         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 919         multicall_cv = cv;                                              \
 920         multicall_cop = CvSTART(cv);                                    \
 921     } STMT_END
 922
 923 #define MULTICALL \
 924     STMT_START {                                                        \
 925         PL_op = multicall_cop;                                          \
 926         CALLRUNOPS(aTHX);                                               \
 927     } STMT_END
 928
 929 #define POP_MULTICALL \
 930     STMT_START {                                                        \
 931         LEAVESUB(multicall_cv);                                         \
 932         CvDEPTH(multicall_cv)--;                                        \
 933         POPBLOCK(cx,PL_curpm);                                          \
 934         POPSTACK;                                                       \
 935         CATCH_SET(multicall_oldcatch);                                  \
 936         LEAVE;                                                          \
 937         SPAGAIN;                                                        \
 938     } STMT_END
 939
 940 /*
 941  * Local variables:
 942  * c-indentation-style: bsd
 943  * c-basic-offset: 4
 944  * indent-tabs-mode: t
 945  * End:
 946  *
 947  * ex: set ts=8 sts=4 sw=4 noet:
 948  */