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_seq;        /* parse sequence number */
 147     line_t      cop_line;       /* line # of this command */
 148     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
 149     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
 150     SV *        cop_io;         /* lexical IO defaults */
 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)->op_private & HINT_ARYBASE)) {                    \
 243             (c)->op_private |= 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)->op_private + 0)
 255 #define CopHINTS_set(c, h)      STMT_START {                            \
 256                                     (c)->op_private                     \
 257                                          = (U8)((h) & HINT_PRIVATE_MASK); \
 258                                 } STMT_END
 259
 260 /*
 261  * Here we have some enormously heavy (or at least ponderous) wizardry.
 262  */
 263
 264 /* subroutine context */
 265 struct block_sub {
 266     CV *        cv;
 267     GV *        gv;
 268     GV *        dfoutgv;
 269     AV *        savearray;
 270     AV *        argarray;
 271     I32         olddepth;
 272     U8          hasargs;
 273     U8          lval;           /* XXX merge lval and hasargs? */
 274     PAD         *oldcomppad;
 275     OP *        retop;  /* op to execute on exit from sub */
 276 };
 277
 278 /* base for the next two macros. Don't use directly.
 279  * Note that the refcnt of the cv is incremented twice;  The CX one is
 280  * decremented by LEAVESUB, the other by LEAVE. */
 281
 282 #define PUSHSUB_BASE(cx)                                                \
 283         cx->blk_sub.cv = cv;                                            \
 284         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
 285         cx->blk_sub.hasargs = hasargs;                                  \
 286         cx->blk_sub.retop = NULL;                                       \
 287         if (!CvDEPTH(cv)) {                                             \
 288             SvREFCNT_inc_simple_void_NN(cv);                            \
 289             SvREFCNT_inc_simple_void_NN(cv);                            \
 290             SAVEFREESV(cv);                                             \
 291         }
 292
 293
 294 #define PUSHSUB(cx)                                                     \
 295         PUSHSUB_BASE(cx)                                                \
 296         cx->blk_sub.lval = PL_op->op_private &                          \
 297                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
 298
 299 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
 300 #define PUSHSUB_DB(cx)                                                  \
 301         PUSHSUB_BASE(cx)                                                \
 302         cx->blk_sub.lval = 0;
 303
 304
 305 #define PUSHFORMAT(cx)                                                  \
 306         cx->blk_sub.cv = cv;                                            \
 307         cx->blk_sub.gv = gv;                                            \
 308         cx->blk_sub.retop = NULL;                                       \
 309         cx->blk_sub.hasargs = 0;                                        \
 310         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
 311         SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
 312
 313 #define POP_SAVEARRAY()                                         \
 314     STMT_START {                                                        \
 315         SvREFCNT_dec(GvAV(PL_defgv));                                   \
 316         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
 317     } STMT_END
 318
 319 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
 320  * leave any (a fast av_clear(ary), basically) */
 321 #define CLEAR_ARGARRAY(ary) \
 322     STMT_START {                                                        \
 323         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
 324         SvPV_set(ary, (char*)AvALLOC(ary));                             \
 325         AvFILLp(ary) = -1;                                              \
 326     } STMT_END
 327
 328 #define POPSUB(cx,sv)                                                   \
 329     STMT_START {                                                        \
 330         if (cx->blk_sub.hasargs) {                                      \
 331             POP_SAVEARRAY();                                            \
 332             /* abandon @_ if it got reified */                          \
 333             if (AvREAL(cx->blk_sub.argarray)) {                         \
 334                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
 335                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
 336                 cx->blk_sub.argarray = newAV();                         \
 337                 av_extend(cx->blk_sub.argarray, fill);                  \
 338                 AvREIFY_only(cx->blk_sub.argarray);                     \
 339                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
 340             }                                                           \
 341             else {                                                      \
 342                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
 343             }                                                           \
 344         }                                                               \
 345         sv = (SV*)cx->blk_sub.cv;                                       \
 346         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
 347             sv = NULL;                                          \
 348     } STMT_END
 349
 350 #define LEAVESUB(sv)                                                    \
 351     STMT_START {                                                        \
 352         if (sv)                                                         \
 353             SvREFCNT_dec(sv);                                           \
 354     } STMT_END
 355
 356 #define POPFORMAT(cx)                                                   \
 357         setdefout(cx->blk_sub.dfoutgv);                                 \
 358         SvREFCNT_dec(cx->blk_sub.dfoutgv);
 359
 360 /* eval context */
 361 struct block_eval {
 362     I32         old_in_eval;
 363     I32         old_op_type;
 364     SV *        old_namesv;
 365     OP *        old_eval_root;
 366     SV *        cur_text;
 367     CV *        cv;
 368     OP *        retop;  /* op to execute on exit from eval */
 369     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
 370 };
 371
 372 #define PUSHEVAL(cx,n,fgv)                                              \
 373     STMT_START {                                                        \
 374         cx->blk_eval.old_in_eval = PL_in_eval;                          \
 375         cx->blk_eval.old_op_type = PL_op->op_type;                      \
 376         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
 377         cx->blk_eval.old_eval_root = PL_eval_root;                      \
 378         cx->blk_eval.cur_text = PL_linestr;                             \
 379         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
 380         cx->blk_eval.retop = NULL;                                      \
 381         cx->blk_eval.cur_top_env = PL_top_env;                          \
 382     } STMT_END
 383
 384 #define POPEVAL(cx)                                                     \
 385     STMT_START {                                                        \
 386         PL_in_eval = cx->blk_eval.old_in_eval;                          \
 387         optype = cx->blk_eval.old_op_type;                              \
 388         PL_eval_root = cx->blk_eval.old_eval_root;                      \
 389         if (cx->blk_eval.old_namesv)                                    \
 390             sv_2mortal(cx->blk_eval.old_namesv);                        \
 391     } STMT_END
 392
 393 /* loop context */
 394 struct block_loop {
 395     char *      label;
 396     I32         resetsp;
 397     OP *        redo_op;
 398     OP *        next_op;
 399     OP *        last_op;
 400 #ifdef USE_ITHREADS
 401     void *      iterdata;
 402     PAD         *oldcomppad;
 403 #else
 404     SV **       itervar;
 405 #endif
 406     SV *        itersave;
 407     SV *        iterlval;
 408     AV *        iterary;
 409     IV          iterix;
 410     IV          itermax;
 411 };
 412
 413 #ifdef USE_ITHREADS
 414 #  define CxITERVAR(c)                                                  \
 415         ((c)->blk_loop.iterdata                                         \
 416          ? (CxPADLOOP(cx)                                               \
 417             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
 418                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
 419             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
 420          : (SV**)NULL)
 421 #  define CX_ITERDATA_SET(cx,idata)                                     \
 422         CX_CURPAD_SAVE(cx->blk_loop);                                   \
 423         if ((cx->blk_loop.iterdata = (idata)))                          \
 424             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 425         else                                                            \
 426             cx->blk_loop.itersave = NULL;
 427 #else
 428 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
 429 #  define CX_ITERDATA_SET(cx,ivar)                                      \
 430         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
 431             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
 432         else                                                            \
 433             cx->blk_loop.itersave = NULL;
 434 #endif
 435
 436 #define PUSHLOOP(cx, dat, s)                                            \
 437         cx->blk_loop.label = PL_curcop->cop_label;                      \
 438         cx->blk_loop.resetsp = s - PL_stack_base;                       \
 439         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
 440         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
 441         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
 442         cx->blk_loop.iterlval = NULL;                                   \
 443         cx->blk_loop.iterary = NULL;                                    \
 444         cx->blk_loop.iterix = -1;                                       \
 445         CX_ITERDATA_SET(cx,dat);
 446
 447 #define POPLOOP(cx)                                                     \
 448         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
 449         if (CxITERVAR(cx)) {                                            \
 450             if (SvPADMY(cx->blk_loop.itersave)) {                       \
 451                 SV ** const s_v_p = CxITERVAR(cx);                      \
 452                 sv_2mortal(*s_v_p);                                     \
 453                 *s_v_p = cx->blk_loop.itersave;                         \
 454             }                                                           \
 455             else {                                                      \
 456                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
 457             }                                                           \
 458         }                                                               \
 459         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
 460             SvREFCNT_dec(cx->blk_loop.iterary);
 461
 462 /* given/when context */
 463 struct block_givwhen {
 464         OP *leave_op;
 465 };
 466
 467 #define PUSHGIVEN(cx)                                                   \
 468         cx->blk_givwhen.leave_op = cLOGOP->op_other;
 469
 470 #define PUSHWHEN PUSHGIVEN
 471
 472 /* context common to subroutines, evals and loops */
 473 struct block {
 474     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
 475     COP *       blku_oldcop;    /* old curcop pointer */
 476     I32         blku_oldmarksp; /* mark stack index */
 477     I32         blku_oldscopesp;        /* scope stack index */
 478     PMOP *      blku_oldpm;     /* values of pattern match vars */
 479     U8          blku_gimme;     /* is this block running in list context? */
 480
 481     union {
 482         struct block_sub        blku_sub;
 483         struct block_eval       blku_eval;
 484         struct block_loop       blku_loop;
 485         struct block_givwhen    blku_givwhen;
 486     } blk_u;
 487 };
 488 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
 489 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
 490 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
 491 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
 492 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
 493 #define blk_gimme       cx_u.cx_blk.blku_gimme
 494 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
 495 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
 496 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
 497 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
 498
 499 /* Enter a block. */
 500 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
 501         cx->cx_type             = t,                                    \
 502         cx->blk_oldsp           = sp - PL_stack_base,                   \
 503         cx->blk_oldcop          = PL_curcop,                            \
 504         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
 505         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
 506         cx->blk_oldpm           = PL_curpm,                             \
 507         cx->blk_gimme           = (U8)gimme;                            \
 508         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
 509                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
 510
 511 /* Exit a block (RETURN and LAST). */
 512 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
 513         newsp            = PL_stack_base + cx->blk_oldsp,               \
 514         PL_curcop        = cx->blk_oldcop,                              \
 515         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 516         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 517         pm               = cx->blk_oldpm,                               \
 518         gimme            = cx->blk_gimme;                               \
 519         DEBUG_SCOPE("POPBLOCK");                                        \
 520         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
 521                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
 522
 523 /* Continue a block elsewhere (NEXT and REDO). */
 524 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
 525         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
 526         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
 527         PL_scopestack_ix = cx->blk_oldscopesp,                          \
 528         PL_curpm         = cx->blk_oldpm;                               \
 529         DEBUG_SCOPE("TOPBLOCK");
 530
 531 /* substitution context */
 532 struct subst {
 533     I32         sbu_iters;
 534     I32         sbu_maxiters;
 535     I32         sbu_rflags;
 536     I32         sbu_oldsave;
 537     bool        sbu_once;
 538     bool        sbu_rxtainted;
 539     char *      sbu_orig;
 540     SV *        sbu_dstr;
 541     SV *        sbu_targ;
 542     char *      sbu_s;
 543     char *      sbu_m;
 544     char *      sbu_strend;
 545     void *      sbu_rxres;
 546     REGEXP *    sbu_rx;
 547 };
 548 #define sb_iters        cx_u.cx_subst.sbu_iters
 549 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
 550 #define sb_rflags       cx_u.cx_subst.sbu_rflags
 551 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
 552 #define sb_once         cx_u.cx_subst.sbu_once
 553 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
 554 #define sb_orig         cx_u.cx_subst.sbu_orig
 555 #define sb_dstr         cx_u.cx_subst.sbu_dstr
 556 #define sb_targ         cx_u.cx_subst.sbu_targ
 557 #define sb_s            cx_u.cx_subst.sbu_s
 558 #define sb_m            cx_u.cx_subst.sbu_m
 559 #define sb_strend       cx_u.cx_subst.sbu_strend
 560 #define sb_rxres        cx_u.cx_subst.sbu_rxres
 561 #define sb_rx           cx_u.cx_subst.sbu_rx
 562
 563 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
 564         cx->sb_iters            = iters,                                \
 565         cx->sb_maxiters         = maxiters,                             \
 566         cx->sb_rflags           = r_flags,                              \
 567         cx->sb_oldsave          = oldsave,                              \
 568         cx->sb_once             = once,                                 \
 569         cx->sb_rxtainted        = rxtainted,                            \
 570         cx->sb_orig             = orig,                                 \
 571         cx->sb_dstr             = dstr,                                 \
 572         cx->sb_targ             = targ,                                 \
 573         cx->sb_s                = s,                                    \
 574         cx->sb_m                = m,                                    \
 575         cx->sb_strend           = strend,                               \
 576         cx->sb_rxres            = NULL,                                 \
 577         cx->sb_rx               = rx,                                   \
 578         cx->cx_type             = CXt_SUBST;                            \
 579         rxres_save(&cx->sb_rxres, rx);                                  \
 580         ReREFCNT_inc(rx)
 581
 582 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
 583         rxres_free(&cx->sb_rxres);                                      \
 584         ReREFCNT_dec(cx->sb_rx)
 585
 586 struct context {
 587     U32         cx_type;        /* what kind of context this is */
 588     union {
 589         struct block    cx_blk;
 590         struct subst    cx_subst;
 591     } cx_u;
 592 };
 593
 594 #define CXTYPEMASK      0xff
 595 #define CXt_NULL        0
 596 #define CXt_SUB         1
 597 #define CXt_EVAL        2
 598 #define CXt_LOOP        3
 599 #define CXt_SUBST       4
 600 #define CXt_BLOCK       5
 601 #define CXt_FORMAT      6
 602 #define CXt_GIVEN       7
 603 #define CXt_WHEN        8
 604
 605 /* private flags for CXt_SUB and CXt_NULL */
 606 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
 607                                            tear down context on exit). */
 608
 609 /* private flags for CXt_EVAL */
 610 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
 611 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
 612
 613 /* private flags for CXt_LOOP */
 614 #define CXp_FOREACH     0x00000200      /* a foreach loop */
 615 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
 616 #ifdef USE_ITHREADS
 617 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
 618                                            has pad offset; if not set,
 619                                            iterdata holds GV* */
 620 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
 621                          == (CXt_LOOP|CXp_PADVAR))
 622 #endif
 623
 624 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
 625 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
 626                          == CXp_MULTICALL)
 627 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
 628                          == (CXt_EVAL|CXp_REAL))
 629 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
 630                          == (CXt_EVAL|CXp_TRYBLOCK))
 631 #define CxFOREACH(c)    (((c)->cx_type & (CXt_LOOP|CXp_FOREACH))        \
 632                          == (CXt_LOOP|CXp_FOREACH))
 633 #define CxFOREACHDEF(c) (((c)->cx_type & (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))\
 634                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
 635
 636 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
 637
 638 /*
 639 =head1 "Gimme" Values
 640 */
 641
 642 /*
 643 =for apidoc AmU||G_SCALAR
 644 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
 645 L<perlcall>.
 646
 647 =for apidoc AmU||G_ARRAY
 648 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
 649 L<perlcall>.
 650
 651 =for apidoc AmU||G_VOID
 652 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
 653
 654 =for apidoc AmU||G_DISCARD
 655 Indicates that arguments returned from a callback should be discarded.  See
 656 L<perlcall>.
 657
 658 =for apidoc AmU||G_EVAL
 659
 660 Used to force a Perl C<eval> wrapper around a callback.  See
 661 L<perlcall>.
 662
 663 =for apidoc AmU||G_NOARGS
 664
 665 Indicates that no arguments are being sent to a callback.  See
 666 L<perlcall>.
 667
 668 =cut
 669 */
 670
 671 #define G_SCALAR        0
 672 #define G_ARRAY         1
 673 #define G_VOID          128     /* skip this bit when adding flags below */
 674
 675 /* extra flags for Perl_call_* routines */
 676 #define G_DISCARD       2       /* Call FREETMPS. */
 677 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
 678 #define G_NOARGS        8       /* Don't construct a @_ array. */
 679 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
 680 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
 681 #define G_METHOD       64       /* Calling method. */
 682 #define G_FAKINGEVAL  256       /* Faking en eval context for call_sv or
 683                                    fold_constants. */
 684
 685 /* flag bits for PL_in_eval */
 686 #define EVAL_NULL       0       /* not in an eval */
 687 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
 688 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
 689 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
 690 #define EVAL_INREQUIRE  8       /* The code is being required. */
 691
 692 /* Support for switching (stack and block) contexts.
 693  * This ensures magic doesn't invalidate local stack and cx pointers.
 694  */
 695
 696 #define PERLSI_UNKNOWN          -1
 697 #define PERLSI_UNDEF            0
 698 #define PERLSI_MAIN             1
 699 #define PERLSI_MAGIC            2
 700 #define PERLSI_SORT             3
 701 #define PERLSI_SIGNAL           4
 702 #define PERLSI_OVERLOAD         5
 703 #define PERLSI_DESTROY          6
 704 #define PERLSI_WARNHOOK         7
 705 #define PERLSI_DIEHOOK          8
 706 #define PERLSI_REQUIRE          9
 707
 708 struct stackinfo {
 709     AV *                si_stack;       /* stack for current runlevel */
 710     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
 711     I32                 si_cxix;        /* current context index */
 712     I32                 si_cxmax;       /* maximum allocated index */
 713     I32                 si_type;        /* type of runlevel */
 714     struct stackinfo *  si_prev;
 715     struct stackinfo *  si_next;
 716     I32                 si_markoff;     /* offset where markstack begins for us.
 717                                          * currently used only with DEBUGGING,
 718                                          * but not #ifdef-ed for bincompat */
 719 };
 720
 721 typedef struct stackinfo PERL_SI;
 722
 723 #define cxstack         (PL_curstackinfo->si_cxstack)
 724 #define cxstack_ix      (PL_curstackinfo->si_cxix)
 725 #define cxstack_max     (PL_curstackinfo->si_cxmax)
 726
 727 #ifdef DEBUGGING
 728 #  define       SET_MARK_OFFSET \
 729     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
 730 #else
 731 #  define       SET_MARK_OFFSET NOOP
 732 #endif
 733
 734 #define PUSHSTACKi(type) \
 735     STMT_START {                                                        \
 736         PERL_SI *next = PL_curstackinfo->si_next;                       \
 737         if (!next) {                                                    \
 738             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
 739             next->si_prev = PL_curstackinfo;                            \
 740             PL_curstackinfo->si_next = next;                            \
 741         }                                                               \
 742         next->si_type = type;                                           \
 743         next->si_cxix = -1;                                             \
 744         AvFILLp(next->si_stack) = 0;                                    \
 745         SWITCHSTACK(PL_curstack,next->si_stack);                        \
 746         PL_curstackinfo = next;                                         \
 747         SET_MARK_OFFSET;                                                \
 748     } STMT_END
 749
 750 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
 751
 752 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
 753  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
 754 #define POPSTACK \
 755     STMT_START {                                                        \
 756         dSP;                                                            \
 757         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
 758         if (!prev) {                                                    \
 759             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
 760             my_exit(1);                                                 \
 761         }                                                               \
 762         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
 763         /* don't free prev here, free them all at the END{} */          \
 764         PL_curstackinfo = prev;                                         \
 765     } STMT_END
 766
 767 #define POPSTACK_TO(s) \
 768     STMT_START {                                                        \
 769         while (PL_curstack != s) {                                      \
 770             dounwind(-1);                                               \
 771             POPSTACK;                                                   \
 772         }                                                               \
 773     } STMT_END
 774
 775 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
 776 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
 777
 778 /*
 779 =head1 Multicall Functions
 780
 781 =for apidoc Ams||dMULTICALL
 782 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
 783
 784 =for apidoc Ams||PUSH_MULTICALL
 785 Opening bracket for a lightweight callback.
 786 See L<perlcall/Lightweight Callbacks>.
 787
 788 =for apidoc Ams||MULTICALL
 789 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
 790
 791 =for apidoc Ams||POP_MULTICALL
 792 Closing bracket for a lightweight callback.
 793 See L<perlcall/Lightweight Callbacks>.
 794
 795 =cut
 796 */
 797
 798 #define dMULTICALL \
 799     SV **newsp;                 /* set by POPBLOCK */                   \
 800     PERL_CONTEXT *cx;                                                   \
 801     CV *multicall_cv;                                                   \
 802     OP *multicall_cop;                                                  \
 803     bool multicall_oldcatch;                                            \
 804     U8 hasargs = 0              /* used by PUSHSUB */
 805
 806 #define PUSH_MULTICALL(the_cv) \
 807     STMT_START {                                                        \
 808         CV * const _nOnclAshIngNamE_ = the_cv;                          \
 809         CV * const cv = _nOnclAshIngNamE_;                              \
 810         AV * const padlist = CvPADLIST(cv);                             \
 811         ENTER;                                                          \
 812         multicall_oldcatch = CATCH_GET;                                 \
 813         SAVETMPS; SAVEVPTR(PL_op);                                      \
 814         CATCH_SET(TRUE);                                                \
 815         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
 816         PUSHSUB(cx);                                                    \
 817         if (++CvDEPTH(cv) >= 2) {                                       \
 818             PERL_STACK_OVERFLOW_CHECK();                                \
 819             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
 820         }                                                               \
 821         SAVECOMPPAD();                                                  \
 822         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
 823         multicall_cv = cv;                                              \
 824         multicall_cop = CvSTART(cv);                                    \
 825     } STMT_END
 826
 827 #define MULTICALL \
 828     STMT_START {                                                        \
 829         PL_op = multicall_cop;                                          \
 830         CALLRUNOPS(aTHX);                                               \
 831     } STMT_END
 832
 833 #define POP_MULTICALL \
 834     STMT_START {                                                        \
 835         LEAVESUB(multicall_cv);                                         \
 836         CvDEPTH(multicall_cv)--;                                        \
 837         POPBLOCK(cx,PL_curpm);                                          \
 838         CATCH_SET(multicall_oldcatch);                                  \
 839         LEAVE;                                                          \
 840     } STMT_END
 841
 842 /*
 843  * Local variables:
 844  * c-indentation-style: bsd
 845  * c-basic-offset: 4
 846  * indent-tabs-mode: t
 847  * End:
 848  *
 849  * ex: set ts=8 sts=4 sw=4 noet:
 850  */