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 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
 136 struct cop {
 137     BASEOP
 138     char *      cop_label;      /* label for this construct */
 139 #ifdef USE_ITHREADS
 140     char *      cop_stashpv;    /* package line was compiled in */
 141     char *      cop_file;       /* file name the following line # is from */
 142 #else
 143     HV *        cop_stash;      /* package line was compiled in */
 144     GV *        cop_filegv;     /* file the following line # is from */
 145 #endif
 146     U32         cop_hints;      /* hints bits from pragmata */
 147     U32         cop_seq;        /* parse sequence number */
 148     line_t      cop_line;       /* line # of this command */
 149     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 150     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 151     /* compile time state of %^H.  See the comment in op.c for how this is
 152        used to recreate a hash to return from caller.  */
 153     struct refcounted_he * cop_hints_hash;
 154 };
 155
 156 #ifdef USE_ITHREADS
 157 #  define CopFILE(c)            ((c)->cop_file)
 158 #  define CopFILEGV(c)          (CopFILE(c) \
 159                                  ? gv_fetchfile(CopFILE(c)) : NULL)
 160
 161 #  ifdef NETWARE
 162 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
 163 #  else
 164 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
 165 #  endif
 166
 167 #  define CopFILESV(c)          (CopFILE(c) \
 168                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
 169 #  define CopFILEAV(c)          (CopFILE(c) \
 170                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
 171 #  ifdef DEBUGGING
 172 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
 173                                    GvAV(gv_fetchfile(CopFILE(c))))
 174 #  else
 175 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
 176 #  endif
 177 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
 178
 179 #  ifdef NETWARE
 180 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
 181 #  else
 182 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
 183 #  endif
 184
 185 #  define CopSTASH(c)           (CopSTASHPV(c) \
 186                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
 187 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
 188 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
 189 #  ifdef NETWARE
 190 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
 191 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
 192 #  else
 193 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
 194 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
 195 #  endif
 196 #else
 197 #  define CopFILEGV(c)          ((c)->cop_filegv)
 198 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
 199 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
 200 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
 201 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
 202 #  ifdef DEBUGGING
 203 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
 204 #  else
 205 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
 206 # endif
 207 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : NULL)
 208 #  define CopSTASH(c)           ((c)->cop_stash)
 209 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
 210 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
 211    /* cop_stash is not refcounted */
 212 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
 213 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
 214 #  define CopSTASH_free(c)
 215 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
 216
 217 #endif /* USE_ITHREADS */
 218
 219 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
 220 #define CopLINE(c)              ((c)->cop_line)
 221 #define CopLINE_inc(c)          (++CopLINE(c))
 222 #define CopLINE_dec(c)          (--CopLINE(c))
 223 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
 224
 225 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
 226 #ifdef MACOS_TRADITIONAL
 227 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
 228 #else
 229 #  define OutCopFILE(c) CopFILE(c)
 230 #endif
 231
 232 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
 233    HINT_ARYBASE is set to indicate this.
 234    Setting it is ineficient due to the need to create 2 mortal SVs, but as
 235    using $[ is highly discouraged, no sane Perl code will be using it.  */
 236 #define CopARYBASE_get(c)       \
 237         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
 238          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
 239                                          "$[", 2, 0, 0))                \
 240          : 0)
 241 #define CopARYBASE_set(c, b) STMT_START { \
 242         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
 243             (c)->cop_hints |= HINT_ARYBASE;                             \
 244             if ((c) == &PL_compiling)                                   \
 245                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
 246             (c)->cop_hints_hash                                         \
 247                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
 248                                         sv_2mortal(newSVpvs("$[")),     \
 249                                         sv_2mortal(newSViv(b)));        \
 250         }                                                               \
 251     } STMT_END
 252
 253 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
 254 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
 255 #define CopHINTS_set(c, h)      STMT_START {                            \
 256                                     (c)->cop_hints = (h);               \
 257                                 } STMT_END
 258
 259 /*
 260  * Here we have some enormously heavy (or at least ponderous) wizardry.
 261  */
 262
 263 /* subroutine context */
 264 struct block_sub {
 265     CV *        cv;
 266     GV *        gv;
 267     GV *        dfoutgv;
 268     AV *        savearray;
 269     AV *        argarray;
 270     I32         olddepth;
 271     U8          hasargs;
 272     U8          lval;           /* XXX merge lval and hasargs? */
 273     PAD         *oldcomppad;
 274     OP *        retop;  /* op to execute on exit from sub */
 275 };
 276
 277 /* base for the next two macros. Don't use directly.
 278  * Note that the refcnt of the cv is incremented twice;  The CX one is
 279  * decremented by LEAVESUB, the other by LEAVE. */
 280
 281 #define PUSHSUB_BASE(cx)                                                \
 282         cx->blk_sub.cv = cv;                                            \
 283         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 284         cx->blk_sub.hasargs = hasargs;                                  \
 285         cx->blk_sub.retop = NULL;                                       \
 286         if (!CvDEPTH(cv)) {                                             \
 287             SvREFCNT_inc_simple_void_NN(cv);                            \
 288             SvREFCNT_inc_simple_void_NN(cv);                            \
 289             SAVEFREESV(cv);                                             \
 290         }
 291
 292
 293 #define PUSHSUB(cx)                                                     \
 294         PUSHSUB_BASE(cx)                                                \
 295         cx->blk_sub.lval = PL_op->op_private &                          \
 296                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 297
 298 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 299 #define PUSHSUB_DB(cx)                                                  \
 300         PUSHSUB_BASE(cx)                                                \
 301         cx->blk_sub.lval = 0;
 302
 303
 304 #define PUSHFORMAT(cx)                                                  \
 305         cx->blk_sub.cv = cv;                                            \
 306         cx->blk_sub.gv = gv;                                            \
 307         cx->blk_sub.retop = NULL;                                       \
 308         cx->blk_sub.hasargs = 0;                                        \
 309         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
 310         SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
 311
 312 #define POP_SAVEARRAY()                                         \
 313     STMT_START {                                                        \
 314         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 315         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 316     } STMT_END
 317
 318 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 319  * leave any (a fast av_clear(ary), basically) */
 320 #define CLEAR_ARGARRAY(ary) \
 321     STMT_START {                                                        \
 322         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 323         SvPV_set(ary, (char*)AvALLOC(ary));                             \
 324         AvFILLp(ary) = -1;                                              \
 325     } STMT_END
 326
 327 #define POPSUB(cx,sv)                                                   \
 328     STMT_START {                                                        \
 329         if (cx->blk_sub.hasargs) {                                      \
 330             POP_SAVEARRAY();                                            \
 331             /* abandon @_ if it got reified */                          \
 332             if (AvREAL(cx->blk_sub.argarray)) {                         \
 333                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
 334                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 335                 cx->blk_sub.argarray = newAV();                         \
 336                 av_extend(cx->blk_sub.argarray, fill);                  \
 337                 AvREIFY_only(cx->blk_sub.argarray);                     \
 338                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
 339             }                                                           \
 340             else {                                                      \
 341                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 342             }                                                           \
 343         }                                                               \
 344         sv = (SV*)cx->blk_sub.cv;                                       \
 345         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 346             sv = NULL;                                          \
 347     } STMT_END
 348
 349 #define LEAVESUB(sv)                                                    \
 350     STMT_START {                                                        \
 351         if (sv)                                                         \
 352             SvREFCNT_dec(sv);                                           \
 353     } STMT_END
 354
 355 #define POPFORMAT(cx)                                                   \
 356         setdefout(cx->blk_sub.dfoutgv);                                 \
 357         SvREFCNT_dec(cx->blk_sub.dfoutgv);
 358
 359 /* eval context */
 360 struct block_eval {
 361     I32         old_in_eval;
 362     I32         old_op_type;
 363     SV *        old_namesv;
 364     OP *        old_eval_root;
 365     SV *        cur_text;
 366     CV *        cv;
 367     OP *        retop;  /* op to execute on exit from eval */
 368     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 369 };
 370
 371 #define PUSHEVAL(cx,n,fgv)                                              \
 372     STMT_START {                                                        \
 373         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 374         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 375         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 376         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 377         cx->blk_eval.cur_text = PL_linestr;                             \
 378         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 379         cx->blk_eval.retop = NULL;                                      \
 380         cx->blk_eval.cur_top_env = PL_top_env;                          \
 381     } STMT_END
 382
 383 #define POPEVAL(cx)                                                     \
 384     STMT_START {                                                        \
 385         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 386         optype = cx->blk_eval.old_op_type;                              \
 387         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 388         if (cx->blk_eval.old_namesv)                                    \
 389             sv_2mortal(cx->blk_eval.old_namesv);                        \
 390     } STMT_END
 391
 392 /* loop context */
 393 struct block_loop {
 394     char *      label;
 395     I32         resetsp;
 396     OP *        redo_op;
 397     OP *        next_op;
 398     OP *        last_op;
 399 #ifdef USE_ITHREADS
 400     void *      iterdata;
 401     PAD         *oldcomppad;
 402 #else
 403     SV **       itervar;
 404 #endif
 405     SV *        itersave;
 406     SV *        iterlval;
 407     AV *        iterary;
 408     IV          iterix;
 409     IV          itermax;
 410 };
 411
 412 #ifdef USE_ITHREADS
 413 #  define CxITERVAR(c)                                                  \
 414         ((c)->blk_loop.iterdata                                         \
 415          ? (CxPADLOOP(cx)                                               \
 416             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 417                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 418             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 419          : (SV**)NULL)
 420 #  define CX_ITERDATA_SET(cx,idata)                                     \
 421         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 422         if ((cx->blk_loop.iterdata = (idata)))                          \
 423             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 424         else                                                            \
 425             cx->blk_loop.itersave = NULL;
 426 #else
 427 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 428 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 429         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 430             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 431         else                                                            \
 432             cx->blk_loop.itersave = NULL;
 433 #endif
 434
 435 #define PUSHLOOP(cx, dat, s)                                            \
 436         cx->blk_loop.label = PL_curcop->cop_label;                      \
 437         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 438         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
 439         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
 440         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
 441         cx->blk_loop.iterlval = NULL;                                   \
 442         cx->blk_loop.iterary = NULL;                                    \
 443         cx->blk_loop.iterix = -1;                                       \
 444         CX_ITERDATA_SET(cx,dat);
 445
 446 #define POPLOOP(cx)                                                     \
 447         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 448         if (CxITERVAR(cx)) {                                            \
 449             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 450                 SV ** const s_v_p = CxITERVAR(cx);                      \
 451                 sv_2mortal(*s_v_p);                                     \
 452                 *s_v_p = cx->blk_loop.itersave;                         \
 453             }                                                           \
 454             else {                                                      \
 455                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 456             }                                                           \
 457         }                                                               \
 458         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 459             SvREFCNT_dec(cx->blk_loop.iterary);
 460
 461 /* given/when context */
 462 struct block_givwhen {
 463         OP *leave_op;
 464 };
 465
 466 #define PUSHGIVEN(cx)                                                   \
 467         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 468
 469 #define PUSHWHEN PUSHGIVEN
 470
 471 /* context common to subroutines, evals and loops */
 472 struct block {
 473     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 474     COP *       blku_oldcop;    /* old curcop pointer */
 475     I32         blku_oldmarksp; /* mark stack index */
 476     I32         blku_oldscopesp;        /* scope stack index */
 477     PMOP *      blku_oldpm;     /* values of pattern match vars */
 478     U8          blku_gimme;     /* is this block running in list context? */
 479
 480     union {
 481         struct block_sub        blku_sub;
 482         struct block_eval       blku_eval;
 483         struct block_loop       blku_loop;
 484         struct block_givwhen    blku_givwhen;
 485     } blk_u;
 486 };
 487 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 488 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 489 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 490 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 491 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 492 #define blk_gimme       cx_u.cx_blk.blku_gimme
 493 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 494 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 495 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 496 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 497
 498 /* Enter a block. */
 499 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 500         cx->cx_type             = t,                                    \
 501         cx->blk_oldsp           = sp - PL_stack_base,                   \
 502         cx->blk_oldcop          = PL_curcop,                            \
 503         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 504         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 505         cx->blk_oldpm           = PL_curpm,                             \
 506         cx->blk_gimme           = (U8)gimme;                            \
 507         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 508                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 509
 510 /* Exit a block (RETURN and LAST). */
 511 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 512         newsp            = PL_stack_base + cx->blk_oldsp,               \
 513         PL_curcop        = cx->blk_oldcop,                              \
 514         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 515         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 516         pm               = cx->blk_oldpm,                               \
 517         gimme            = cx->blk_gimme;                               \
 518         DEBUG_SCOPE("POPBLOCK");                                        \
 519         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 520                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 521
 522 /* Continue a block elsewhere (NEXT and REDO). */
 523 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 524         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 525         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 526         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 527         PL_curpm         = cx->blk_oldpm;                               \
 528         DEBUG_SCOPE("TOPBLOCK");
 529
 530 /* substitution context */
 531 struct subst {
 532     I32         sbu_iters;
 533     I32         sbu_maxiters;
 534     I32         sbu_rflags;
 535     I32         sbu_oldsave;
 536     bool        sbu_once;
 537     bool        sbu_rxtainted;
 538     char *      sbu_orig;
 539     SV *        sbu_dstr;
 540     SV *        sbu_targ;
 541     char *      sbu_s;
 542     char *      sbu_m;
 543     char *      sbu_strend;
 544     void *      sbu_rxres;
 545     REGEXP *    sbu_rx;
 546 };
 547 #define sb_iters        cx_u.cx_subst.sbu_iters
 548 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 549 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 550 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 551 #define sb_once         cx_u.cx_subst.sbu_once
 552 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 553 #define sb_orig         cx_u.cx_subst.sbu_orig
 554 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 555 #define sb_targ         cx_u.cx_subst.sbu_targ
 556 #define sb_s            cx_u.cx_subst.sbu_s
 557 #define sb_m            cx_u.cx_subst.sbu_m
 558 #define sb_strend       cx_u.cx_subst.sbu_strend
 559 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 560 #define sb_rx           cx_u.cx_subst.sbu_rx
 561
 562 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 563         cx->sb_iters            = iters,                                \
 564         cx->sb_maxiters         = maxiters,                             \
 565         cx->sb_rflags           = r_flags,                              \
 566         cx->sb_oldsave          = oldsave,                              \
 567         cx->sb_once             = once,                                 \
 568         cx->sb_rxtainted        = rxtainted,                            \
 569         cx->sb_orig             = orig,                                 \
 570         cx->sb_dstr             = dstr,                                 \
 571         cx->sb_targ             = targ,                                 \
 572         cx->sb_s                = s,                                    \
 573         cx->sb_m                = m,                                    \
 574         cx->sb_strend           = strend,                               \
 575         cx->sb_rxres            = NULL,                                 \
 576         cx->sb_rx               = rx,                                   \
 577         cx->cx_type             = CXt_SUBST;                            \
 578         rxres_save(&cx->sb_rxres, rx);                                  \
 579         ReREFCNT_inc(rx)
 580
 581 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 582         rxres_free(&cx->sb_rxres);                                      \
 583         ReREFCNT_dec(cx->sb_rx)
 584
 585 struct context {
 586     U32         cx_type;        /* what kind of context this is */
 587     union {
 588         struct block    cx_blk;
 589         struct subst    cx_subst;
 590     } cx_u;
 591 };
 592
 593 #define CXTYPEMASK      0xff
 594 #define CXt_NULL        0
 595 #define CXt_SUB         1
 596 #define CXt_EVAL        2
 597 #define CXt_LOOP        3
 598 #define CXt_SUBST       4
 599 #define CXt_BLOCK       5
 600 #define CXt_FORMAT      6
 601 #define CXt_GIVEN       7
 602 #define CXt_WHEN        8
 603
 604 /* private flags for CXt_SUB and CXt_NULL */
 605 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
 606                                            tear down context on exit). */
 607
 608 /* private flags for CXt_EVAL */
 609 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 610 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 611
 612 /* private flags for CXt_LOOP */
 613 #define CXp_FOREACH     0x00000200      /* a foreach loop */
 614 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
 615 #ifdef USE_ITHREADS
 616 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 617                                            has pad offset; if not set,
 618                                            iterdata holds GV* */
 619 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 620                          == (CXt_LOOP|CXp_PADVAR))
 621 #endif
 622
 623 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 624 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 625                          == CXp_MULTICALL)
 626 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
 627                          == (CXt_EVAL|CXp_REAL))
 628 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
 629                          == (CXt_EVAL|CXp_TRYBLOCK))
 630 #define CxFOREACH(c)    (((c)->cx_type & (CXt_LOOP|CXp_FOREACH))        \
 631                          == (CXt_LOOP|CXp_FOREACH))
 632 #define CxFOREACHDEF(c) (((c)->cx_type & (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))\
 633                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 634
 635 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 636
 637 /*
 638 =head1 "Gimme" Values
 639 */
 640
 641 /*
 642 =for apidoc AmU||G_SCALAR
 643 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 644 L<perlcall>.
 645
 646 =for apidoc AmU||G_ARRAY
 647 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 648 L<perlcall>.
 649
 650 =for apidoc AmU||G_VOID
 651 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 652
 653 =for apidoc AmU||G_DISCARD
 654 Indicates that arguments returned from a callback should be discarded.  See
 655 L<perlcall>.
 656
 657 =for apidoc AmU||G_EVAL
 658
 659 Used to force a Perl C<eval> wrapper around a callback.  See
 660 L<perlcall>.
 661
 662 =for apidoc AmU||G_NOARGS
 663
 664 Indicates that no arguments are being sent to a callback.  See
 665 L<perlcall>.
 666
 667 =cut
 668 */
 669
 670 #define G_SCALAR        0
 671 #define G_ARRAY         1
 672 #define G_VOID          128     /* skip this bit when adding flags below */
 673
 674 /* extra flags for Perl_call_* routines */
 675 #define G_DISCARD       2       /* Call FREETMPS. */
 676 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 677 #define G_NOARGS        8       /* Don't construct a @_ array. */
 678 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 679 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 680 #define G_METHOD       64       /* Calling method. */
 681 #define G_FAKINGEVAL  256       /* Faking en eval context for call_sv or
 682                                    fold_constants. */
 683
 684 /* flag bits for PL_in_eval */
 685 #define EVAL_NULL       0       /* not in an eval */
 686 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 687 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 688 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 689 #define EVAL_INREQUIRE  8       /* The code is being required. */
 690
 691 /* Support for switching (stack and block) contexts.
 692  * This ensures magic doesn't invalidate local stack and cx pointers.
 693  */
 694
 695 #define PERLSI_UNKNOWN          -1
 696 #define PERLSI_UNDEF            0
 697 #define PERLSI_MAIN             1
 698 #define PERLSI_MAGIC            2
 699 #define PERLSI_SORT             3
 700 #define PERLSI_SIGNAL           4
 701 #define PERLSI_OVERLOAD         5
 702 #define PERLSI_DESTROY          6
 703 #define PERLSI_WARNHOOK         7
 704 #define PERLSI_DIEHOOK          8
 705 #define PERLSI_REQUIRE          9
 706
 707 struct stackinfo {
 708     AV *                si_stack;       /* stack for current runlevel */
 709     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 710     I32                 si_cxix;        /* current context index */
 711     I32                 si_cxmax;       /* maximum allocated index */
 712     I32                 si_type;        /* type of runlevel */
 713     struct stackinfo *  si_prev;
 714     struct stackinfo *  si_next;
 715     I32                 si_markoff;     /* offset where markstack begins for us.
 716                                          * currently used only with DEBUGGING,
 717                                          * but not #ifdef-ed for bincompat */
 718 };
 719
 720 typedef struct stackinfo PERL_SI;
 721
 722 #define cxstack         (PL_curstackinfo->si_cxstack)
 723 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 724 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 725
 726 #ifdef DEBUGGING
 727 #  define       SET_MARK_OFFSET \
 728     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 729 #else
 730 #  define       SET_MARK_OFFSET NOOP
 731 #endif
 732
 733 #define PUSHSTACKi(type) \
 734     STMT_START {                                                        \
 735         PERL_SI *next = PL_curstackinfo->si_next;                       \
 736         if (!next) {                                                    \
 737             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 738             next->si_prev = PL_curstackinfo;                            \
 739             PL_curstackinfo->si_next = next;                            \
 740         }                                                               \
 741         next->si_type = type;                                           \
 742         next->si_cxix = -1;                                             \
 743         AvFILLp(next->si_stack) = 0;                                    \
 744         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 745         PL_curstackinfo = next;                                         \
 746         SET_MARK_OFFSET;                                                \
 747     } STMT_END
 748
 749 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 750
 751 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 752  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 753 #define POPSTACK \
 754     STMT_START {                                                        \
 755         dSP;                                                            \
 756         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 757         if (!prev) {                                                    \
 758             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 759             my_exit(1);                                                 \
 760         }                                                               \
 761         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 762         /* don't free prev here, free them all at the END{} */          \
 763         PL_curstackinfo = prev;                                         \
 764     } STMT_END
 765
 766 #define POPSTACK_TO(s) \
 767     STMT_START {                                                        \
 768         while (PL_curstack != s) {                                      \
 769             dounwind(-1);                                               \
 770             POPSTACK;                                                   \
 771         }                                                               \
 772     } STMT_END
 773
 774 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 775 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 776
 777 /*
 778 =head1 Multicall Functions
 779
 780 =for apidoc Ams||dMULTICALL
 781 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 782
 783 =for apidoc Ams||PUSH_MULTICALL
 784 Opening bracket for a lightweight callback.
 785 See L<perlcall/Lightweight Callbacks>.
 786
 787 =for apidoc Ams||MULTICALL
 788 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 789
 790 =for apidoc Ams||POP_MULTICALL
 791 Closing bracket for a lightweight callback.
 792 See L<perlcall/Lightweight Callbacks>.
 793
 794 =cut
 795 */
 796
 797 #define dMULTICALL \
 798     SV **newsp;                 /* set by POPBLOCK */                   \
 799     PERL_CONTEXT *cx;                                                   \
 800     CV *multicall_cv;                                                   \
 801     OP *multicall_cop;                                                  \
 802     bool multicall_oldcatch;                                            \
 803     U8 hasargs = 0              /* used by PUSHSUB */
 804
 805 #define PUSH_MULTICALL(the_cv) \
 806     STMT_START {                                                        \
 807         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 808         CV * const cv = _nOnclAshIngNamE_;                              \
 809         AV * const padlist = CvPADLIST(cv);                             \
 810         ENTER;                                                          \
 811         multicall_oldcatch = CATCH_GET;                                 \
 812         SAVETMPS; SAVEVPTR(PL_op);                                      \
 813         CATCH_SET(TRUE);                                                \
 814         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 815         PUSHSUB(cx);                                                    \
 816         if (++CvDEPTH(cv) >= 2) {                                       \
 817             PERL_STACK_OVERFLOW_CHECK();                                \
 818             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 819         }                                                               \
 820         SAVECOMPPAD();                                                  \
 821         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 822         multicall_cv = cv;                                              \
 823         multicall_cop = CvSTART(cv);                                    \
 824     } STMT_END
 825
 826 #define MULTICALL \
 827     STMT_START {                                                        \
 828         PL_op = multicall_cop;                                          \
 829         CALLRUNOPS(aTHX);                                               \
 830     } STMT_END
 831
 832 #define POP_MULTICALL \
 833     STMT_START {                                                        \
 834         LEAVESUB(multicall_cv);                                         \
 835         CvDEPTH(multicall_cv)--;                                        \
 836         POPBLOCK(cx,PL_curpm);                                          \
 837         CATCH_SET(multicall_oldcatch);                                  \
 838         LEAVE;                                                          \
 839     } STMT_END
 840
 841 /*
 842  * Local variables:
 843  * c-indentation-style: bsd
 844  * c-basic-offset: 4
 845  * indent-tabs-mode: t
 846  * End:
 847  *
 848  * ex: set ts=8 sts=4 sw=4 noet:
 849  */