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Add a flag G_WANT, as a mask for the bits G_SCALAR, G_ARRAY and G_VOID.
[perl5.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4  *    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
10  * and OP_SETSTATE that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a start_env initialized when perl starts, and top_env
18  * points to this initially, so top_env should always be non-null.
19  *
20  * Existence of a non-null top_env->je_prev implies it is valid to call
21  * longjmp() at that runlevel (we make sure start_env.je_prev is always
22  * null to ensure this).
23  *
24  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
25  * establish a local jmpenv to handle exception traps.  Care must be taken
26  * to restore the previous value of je_mustcatch before exiting the
27  * stack frame iff JMPENV_PUSH was not called in that stack frame.
28  * GSAR 97-03-27
29  */
30
31 struct jmpenv {
32     struct jmpenv *     je_prev;
33     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
34     int                 je_ret;         /* last exception thrown */
35     bool                je_mustcatch;   /* need to call longjmp()? */
36 };
37
38 typedef struct jmpenv JMPENV;
39
40 #ifdef OP_IN_REGISTER
41 #define OP_REG_TO_MEM   PL_opsave = op
42 #define OP_MEM_TO_REG   op = PL_opsave
43 #else
44 #define OP_REG_TO_MEM   NOOP
45 #define OP_MEM_TO_REG   NOOP
46 #endif
47
48 /*
49  * How to build the first jmpenv.
50  *
51  * top_env needs to be non-zero. It points to an area
52  * in which longjmp() stuff is stored, as C callstack
53  * info there at least is thread specific this has to
54  * be per-thread. Otherwise a 'die' in a thread gives
55  * that thread the C stack of last thread to do an eval {}!
56  */
57
58 #define JMPENV_BOOTSTRAP \
59     STMT_START {                                \
60         Zero(&PL_start_env, 1, JMPENV);         \
61         PL_start_env.je_ret = -1;               \
62         PL_start_env.je_mustcatch = TRUE;       \
63         PL_top_env = &PL_start_env;             \
64     } STMT_END
65
66 /*
67  *   PERL_FLEXIBLE_EXCEPTIONS
68  * 
69  * All the flexible exceptions code has been removed.
70  * See the following threads for details:
71  *
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
73  * 
74  * Joshua's original patches (which weren't applied) and discussion:
75  * 
76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
82  * 
83  * Chip's reworked patch and discussion:
84  * 
85  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
86  * 
87  * The flaw in these patches (which went unnoticed at the time) was
88  * that they moved some code that could potentially die() out of the
89  * region protected by the setjmp()s.  This caused exceptions within
90  * END blocks and such to not be handled by the correct setjmp().
91  * 
92  * The original patches that introduces flexible exceptions were:
93  *
94  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
96  */
97
98 #define dJMPENV         JMPENV cur_env
99
100 #define JMPENV_PUSH(v) \
101     STMT_START {                                                        \
102         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
103                          (void*)&cur_env, (void*)PL_top_env));                  \
104         cur_env.je_prev = PL_top_env;                                   \
105         OP_REG_TO_MEM;                                                  \
106         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
107         OP_MEM_TO_REG;                                                  \
108         PL_top_env = &cur_env;                                          \
109         cur_env.je_mustcatch = FALSE;                                   \
110         (v) = cur_env.je_ret;                                           \
111     } STMT_END
112
113 #define JMPENV_POP \
114     STMT_START {                                                        \
115         DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
116                          (void*)PL_top_env, (void*)cur_env.je_prev));                   \
117         PL_top_env = cur_env.je_prev;                                   \
118     } STMT_END
119
120 #define JMPENV_JUMP(v) \
121     STMT_START {                                                \
122         OP_REG_TO_MEM;                                          \
123         if (PL_top_env->je_prev)                                \
124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
125         if ((v) == 2)                                           \
126             PerlProc_exit(STATUS_EXIT);                         \
127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
128         PerlProc_exit(1);                                       \
129     } STMT_END
130
131 #define CATCH_GET               (PL_top_env->je_mustcatch)
132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
133
134
135 #include "mydtrace.h"
136
137 struct cop {
138     BASEOP
139     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
140        an exact multiple of 8 bytes to save structure padding.  */
141     line_t      cop_line;       /* line # of this command */
142     char *      cop_label;      /* label for this construct */
143 #ifdef USE_ITHREADS
144     char *      cop_stashpv;    /* package line was compiled in */
145     char *      cop_file;       /* file name the following line # is from */
146 #else
147     HV *        cop_stash;      /* package line was compiled in */
148     GV *        cop_filegv;     /* file the following line # is from */
149 #endif
150     U32         cop_hints;      /* hints bits from pragmata */
151     U32         cop_seq;        /* parse sequence number */
152     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
153     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
154     /* compile time state of %^H.  See the comment in op.c for how this is
155        used to recreate a hash to return from caller.  */
156     struct refcounted_he * cop_hints_hash;
157 };
158
159 #ifdef USE_ITHREADS
160 #  define CopFILE(c)            ((c)->cop_file)
161 #  define CopFILEGV(c)          (CopFILE(c) \
162                                  ? gv_fetchfile(CopFILE(c)) : NULL)
163                                  
164 #  ifdef NETWARE
165 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
166 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
167 #  else
168 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
169 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
170 #  endif
171
172 #  define CopFILESV(c)          (CopFILE(c) \
173                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
174 #  define CopFILEAV(c)          (CopFILE(c) \
175                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
176 #  ifdef DEBUGGING
177 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
178                                    GvAV(gv_fetchfile(CopFILE(c))))
179 #  else
180 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
181 #  endif
182 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
183
184 #  ifdef NETWARE
185 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
186 #  else
187 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
188 #  endif
189
190 #  define CopSTASH(c)           (CopSTASHPV(c) \
191                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
192 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
193 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
194 #  define CopLABEL(c)           ((c)->cop_label)
195 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
196 #  ifdef NETWARE
197 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
198 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
199 #    define CopLABEL_free(c) SAVECOPLABEL_FREE(c)
200 #    define CopLABEL_alloc(pv)  ((pv)?savepv(pv):NULL)
201 #  else
202 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
203 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
204 #    define CopLABEL_free(c)    (PerlMemShared_free(CopLABEL(c)),(CopLABEL(c) = NULL))
205 #    define CopLABEL_alloc(pv)  ((pv)?savesharedpv(pv):NULL)
206 #  endif
207 #else
208 #  define CopFILEGV(c)          ((c)->cop_filegv)
209 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
210 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
211 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
212 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
213 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
214 #  ifdef DEBUGGING
215 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
216 #  else
217 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
218 # endif
219 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
220                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
221 #  define CopSTASH(c)           ((c)->cop_stash)
222 #  define CopLABEL(c)           ((c)->cop_label)
223 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
224 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
225    /* cop_stash is not refcounted */
226 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
227 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
228 #  define CopLABEL_alloc(pv)    ((pv)?savepv(pv):NULL)
229 #  define CopLABEL_set(c,pv)    (CopLABEL(c) = (pv))
230 #  define CopSTASH_free(c)      
231 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
232 #  define CopLABEL_free(c)      (Safefree(CopLABEL(c)),(CopLABEL(c) = NULL))
233
234 #endif /* USE_ITHREADS */
235
236 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
237 #define CopLINE(c)              ((c)->cop_line)
238 #define CopLINE_inc(c)          (++CopLINE(c))
239 #define CopLINE_dec(c)          (--CopLINE(c))
240 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
241
242 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
243 #ifdef MACOS_TRADITIONAL
244 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
245 #else
246 #  define OutCopFILE(c) CopFILE(c)
247 #endif
248
249 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
250    HINT_ARYBASE is set to indicate this.
251    Setting it is ineficient due to the need to create 2 mortal SVs, but as
252    using $[ is highly discouraged, no sane Perl code will be using it.  */
253 #define CopARYBASE_get(c)       \
254         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
255          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
256                                          "$[", 2, 0, 0))                \
257          : 0)
258 #define CopARYBASE_set(c, b) STMT_START { \
259         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
260             (c)->cop_hints |= HINT_ARYBASE;                             \
261             if ((c) == &PL_compiling)                                   \
262                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
263             (c)->cop_hints_hash                                         \
264                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
265                                         newSVpvs_flags("$[", SVs_TEMP), \
266                                         sv_2mortal(newSViv(b)));        \
267         }                                                               \
268     } STMT_END
269
270 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
271 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
272 #define CopHINTS_set(c, h)      STMT_START {                            \
273                                     (c)->cop_hints = (h);               \
274                                 } STMT_END
275
276 /*
277  * Here we have some enormously heavy (or at least ponderous) wizardry.
278  */
279
280 /* subroutine context */
281 struct block_sub {
282     OP *        retop;  /* op to execute on exit from sub */
283     /* Above here is the same for sub, format and eval.  */
284     CV *        cv;
285     U8          lval;           /* XXX merge lval and hasargs? */
286     /* Above here is the same for sub and format.  */
287     AV *        savearray;
288     AV *        argarray;
289     I32         olddepth;
290     PAD         *oldcomppad;
291 };
292
293
294 /* format context */
295 struct block_format {
296     OP *        retop;  /* op to execute on exit from sub */
297     /* Above here is the same for sub, format and eval.  */
298     CV *        cv;
299     U8          lval;           /* XXX merge lval and hasargs? */
300     /* Above here is the same for sub and format.  */
301     GV *        gv;
302     GV *        dfoutgv;
303 };
304
305 /* base for the next two macros. Don't use directly.
306  * Note that the refcnt of the cv is incremented twice;  The CX one is
307  * decremented by LEAVESUB, the other by LEAVE. */
308
309 #define PUSHSUB_BASE(cx)                                                \
310         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
311                 CopFILE((COP*)CvSTART(cv)),                             \
312                 CopLINE((COP*)CvSTART(cv)));                            \
313                                                                         \
314         cx->blk_sub.cv = cv;                                            \
315         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
316         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
317         cx->blk_sub.retop = NULL;                                       \
318         if (!CvDEPTH(cv)) {                                             \
319             SvREFCNT_inc_simple_void_NN(cv);                            \
320             SvREFCNT_inc_simple_void_NN(cv);                            \
321             SAVEFREESV(cv);                                             \
322         }
323
324
325 #define PUSHSUB(cx)                                                     \
326         PUSHSUB_BASE(cx)                                                \
327         cx->blk_sub.lval = PL_op->op_private &                          \
328                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
329
330 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
331 #define PUSHSUB_DB(cx)                                                  \
332         PUSHSUB_BASE(cx)                                                \
333         cx->blk_sub.lval = 0;
334
335
336 #define PUSHFORMAT(cx, retop)                                           \
337         cx->blk_format.cv = cv;                                         \
338         cx->blk_format.gv = gv;                                         \
339         cx->blk_format.retop = (retop);                                 \
340         cx->blk_format.dfoutgv = PL_defoutgv;                           \
341         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
342
343 #define POP_SAVEARRAY()                                         \
344     STMT_START {                                                        \
345         SvREFCNT_dec(GvAV(PL_defgv));                                   \
346         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
347     } STMT_END
348
349 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
350  * leave any (a fast av_clear(ary), basically) */
351 #define CLEAR_ARGARRAY(ary) \
352     STMT_START {                                                        \
353         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
354         AvARRAY(ary) = AvALLOC(ary);                                    \
355         AvFILLp(ary) = -1;                                              \
356     } STMT_END
357
358 #define POPSUB(cx,sv)                                                   \
359     STMT_START {                                                        \
360         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
361                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
362                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
363                                                                         \
364         if (CxHASARGS(cx)) {                                            \
365             POP_SAVEARRAY();                                            \
366             /* abandon @_ if it got reified */                          \
367             if (AvREAL(cx->blk_sub.argarray)) {                         \
368                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
369                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
370                 cx->blk_sub.argarray = newAV();                         \
371                 av_extend(cx->blk_sub.argarray, fill);                  \
372                 AvREIFY_only(cx->blk_sub.argarray);                     \
373                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
374             }                                                           \
375             else {                                                      \
376                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
377             }                                                           \
378         }                                                               \
379         sv = (SV*)cx->blk_sub.cv;                                       \
380         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
381             sv = NULL;                                          \
382     } STMT_END
383
384 #define LEAVESUB(sv)                                                    \
385     STMT_START {                                                        \
386         if (sv)                                                         \
387             SvREFCNT_dec(sv);                                           \
388     } STMT_END
389
390 #define POPFORMAT(cx)                                                   \
391         setdefout(cx->blk_format.dfoutgv);                              \
392         SvREFCNT_dec(cx->blk_format.dfoutgv);
393
394 /* eval context */
395 struct block_eval {
396     OP *        retop;  /* op to execute on exit from eval */
397     /* Above here is the same for sub, format and eval.  */
398     U8          old_in_eval;
399     U16         old_op_type;
400     SV *        old_namesv;
401     OP *        old_eval_root;
402     SV *        cur_text;
403     CV *        cv;
404     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
405 };
406
407 #define PUSHEVAL(cx,n,fgv)                                              \
408     STMT_START {                                                        \
409         cx->blk_eval.old_in_eval = PL_in_eval;                          \
410         cx->blk_eval.old_op_type = PL_op->op_type;                      \
411         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
412         cx->blk_eval.old_eval_root = PL_eval_root;                      \
413         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
414         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
415         cx->blk_eval.retop = NULL;                                      \
416         cx->blk_eval.cur_top_env = PL_top_env;                          \
417     } STMT_END
418
419 #define POPEVAL(cx)                                                     \
420     STMT_START {                                                        \
421         PL_in_eval = cx->blk_eval.old_in_eval;                          \
422         optype = cx->blk_eval.old_op_type;                              \
423         PL_eval_root = cx->blk_eval.old_eval_root;                      \
424         if (cx->blk_eval.old_namesv)                                    \
425             sv_2mortal(cx->blk_eval.old_namesv);                        \
426     } STMT_END
427
428 /* loop context */
429 struct block_loop {
430     I32         resetsp;
431     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
432     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
433         why next_op is conditionally defined below.)  */
434 #ifdef USE_ITHREADS
435     void *      iterdata;
436     PAD         *oldcomppad;
437 #else
438     OP *        next_op;
439     SV **       itervar;
440 #endif
441     SV *        itersave;
442     /* (from inspection of source code) for a .. range of strings this is the
443        current string.  */
444     SV *        iterlval;
445     /* (from inspection of source code) for a foreach loop this is the array
446        being iterated over. For a .. range of numbers it's the current value.
447        A check is often made on the SvTYPE of iterary to determine whether
448        we are iterating over an array or a range. (numbers or strings)  */
449     AV *        iterary;
450     IV          iterix;
451     /* (from inspection of source code) for a .. range of numbers this is the
452        maximum value.  */
453     IV          itermax;
454 };
455 /* It might be possible to squeeze this structure further. As best I can tell
456    itermax and iterlval are never used at the same time, so it might be possible
457    to make them into a union. However, I'm not confident that there are enough
458    flag bits/NULLable pointers in this structure alone to encode which is
459    active. There is, however, U8 of space free in struct block, which could be
460    used. Right now it may not be worth squeezing this structure further, as it's
461    the largest part of struct block, and currently struct block is 64 bytes on
462    an ILP32 system, which will give good cache alignment.
463 */
464
465 #ifdef USE_ITHREADS
466 #  define CxITERVAR(c)                                                  \
467         ((c)->blk_loop.iterdata                                         \
468          ? (CxPADLOOP(cx)                                               \
469             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
470                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
471             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
472          : (SV**)NULL)
473 #  define CX_ITERDATA_SET(cx,idata)                                     \
474         CX_CURPAD_SAVE(cx->blk_loop);                                   \
475         if ((cx->blk_loop.iterdata = (idata)))                          \
476             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
477         else                                                            \
478             cx->blk_loop.itersave = NULL;
479 #else
480 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
481 #  define CX_ITERDATA_SET(cx,ivar)                                      \
482         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
483             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
484         else                                                            \
485             cx->blk_loop.itersave = NULL;
486 #endif
487 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
488 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
489 #define CxLVAL(c)       (0 + (c)->blk_sub.lval)
490
491 #ifdef USE_ITHREADS
492 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
493 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
494 #else
495 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
496 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
497 #endif
498
499 #define PUSHLOOP(cx, dat, s)                                            \
500         cx->blk_loop.resetsp = s - PL_stack_base;                       \
501         cx->blk_loop.my_op = cLOOP;                                     \
502         PUSHLOOP_OP_NEXT;                                               \
503         cx->blk_loop.iterlval = NULL;                                   \
504         cx->blk_loop.iterary = NULL;                                    \
505         cx->blk_loop.iterix = -1;                                       \
506         CX_ITERDATA_SET(cx,dat);
507
508 #define POPLOOP(cx)                                                     \
509         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
510         if (CxITERVAR(cx)) {                                            \
511             if (SvPADMY(cx->blk_loop.itersave)) {                       \
512                 SV ** const s_v_p = CxITERVAR(cx);                      \
513                 sv_2mortal(*s_v_p);                                     \
514                 *s_v_p = cx->blk_loop.itersave;                         \
515             }                                                           \
516             else {                                                      \
517                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
518             }                                                           \
519         }                                                               \
520         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
521             SvREFCNT_dec(cx->blk_loop.iterary);
522
523 /* given/when context */
524 struct block_givwhen {
525         OP *leave_op;
526 };
527
528 #define PUSHGIVEN(cx)                                                   \
529         cx->blk_givwhen.leave_op = cLOGOP->op_other;
530
531 #define PUSHWHEN PUSHGIVEN
532
533 /* context common to subroutines, evals and loops */
534 struct block {
535     U16         blku_type;      /* what kind of context this is */
536     U8          blku_gimme;     /* is this block running in list context? */
537     U8          blku_spare;     /* Padding to match with struct subst */
538     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
539     COP *       blku_oldcop;    /* old curcop pointer */
540     I32         blku_oldmarksp; /* mark stack index */
541     I32         blku_oldscopesp;        /* scope stack index */
542     PMOP *      blku_oldpm;     /* values of pattern match vars */
543
544     union {
545         struct block_sub        blku_sub;
546         struct block_format     blku_format;
547         struct block_eval       blku_eval;
548         struct block_loop       blku_loop;
549         struct block_givwhen    blku_givwhen;
550     } blk_u;
551 };
552 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
553 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
554 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
555 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
556 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
557 #define blk_gimme       cx_u.cx_blk.blku_gimme
558 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
559 #define blk_format      cx_u.cx_blk.blk_u.blku_format
560 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
561 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
562 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
563
564 /* Enter a block. */
565 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
566         cx->cx_type             = t,                                    \
567         cx->blk_oldsp           = sp - PL_stack_base,                   \
568         cx->blk_oldcop          = PL_curcop,                            \
569         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
570         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
571         cx->blk_oldpm           = PL_curpm,                             \
572         cx->blk_gimme           = (U8)gimme;                            \
573         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
574                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
575
576 /* Exit a block (RETURN and LAST). */
577 #define POPBLOCK(cx,pm) 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         DEBUG_SCOPE("POPBLOCK");                                        \
585         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
586                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
587
588 /* Continue a block elsewhere (NEXT and REDO). */
589 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
590         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
591         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
592         PL_scopestack_ix = cx->blk_oldscopesp,                          \
593         PL_curpm         = cx->blk_oldpm;                               \
594         DEBUG_SCOPE("TOPBLOCK");
595
596 /* substitution context */
597 struct subst {
598     U16         sbu_type;       /* what kind of context this is */
599     U8          sbu_once;       /* Actually both booleans, but U8 to matches */
600     U8          sbu_rxtainted;  /* struct block */
601     I32         sbu_iters;
602     I32         sbu_maxiters;
603     I32         sbu_rflags;
604     I32         sbu_oldsave;
605     char *      sbu_orig;
606     SV *        sbu_dstr;
607     SV *        sbu_targ;
608     char *      sbu_s;
609     char *      sbu_m;
610     char *      sbu_strend;
611     void *      sbu_rxres;
612     REGEXP *    sbu_rx;
613 };
614 #define sb_iters        cx_u.cx_subst.sbu_iters
615 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
616 #define sb_rflags       cx_u.cx_subst.sbu_rflags
617 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
618 #define sb_once         cx_u.cx_subst.sbu_once
619 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
620 #define sb_orig         cx_u.cx_subst.sbu_orig
621 #define sb_dstr         cx_u.cx_subst.sbu_dstr
622 #define sb_targ         cx_u.cx_subst.sbu_targ
623 #define sb_s            cx_u.cx_subst.sbu_s
624 #define sb_m            cx_u.cx_subst.sbu_m
625 #define sb_strend       cx_u.cx_subst.sbu_strend
626 #define sb_rxres        cx_u.cx_subst.sbu_rxres
627 #define sb_rx           cx_u.cx_subst.sbu_rx
628
629 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
630         cx->sb_iters            = iters,                                \
631         cx->sb_maxiters         = maxiters,                             \
632         cx->sb_rflags           = r_flags,                              \
633         cx->sb_oldsave          = oldsave,                              \
634         cx->sb_once             = once,                                 \
635         cx->sb_rxtainted        = rxtainted,                            \
636         cx->sb_orig             = orig,                                 \
637         cx->sb_dstr             = dstr,                                 \
638         cx->sb_targ             = targ,                                 \
639         cx->sb_s                = s,                                    \
640         cx->sb_m                = m,                                    \
641         cx->sb_strend           = strend,                               \
642         cx->sb_rxres            = NULL,                                 \
643         cx->sb_rx               = rx,                                   \
644         cx->cx_type             = CXt_SUBST;                            \
645         rxres_save(&cx->sb_rxres, rx);                                  \
646         (void)ReREFCNT_inc(rx)
647
648 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
649         rxres_free(&cx->sb_rxres);                                      \
650         ReREFCNT_dec(cx->sb_rx)
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 #define CXTYPEMASK      0xff
661 #define CXt_NULL        0
662 #define CXt_SUB         1
663 #define CXt_EVAL        2
664 #define CXt_LOOP        3
665 #define CXt_SUBST       4
666 #define CXt_BLOCK       5
667 #define CXt_FORMAT      6
668 #define CXt_GIVEN       7
669 #define CXt_WHEN        8
670
671 /* private flags for CXt_SUB and CXt_NULL */
672 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
673                                            tear down context on exit). */ 
674
675 /* private flags for CXt_SUB and CXt_FORMAT */
676 #define CXp_HASARGS     0x00000200
677
678 /* private flags for CXt_EVAL */
679 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
680 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
681
682 /* private flags for CXt_LOOP */
683 #define CXp_FOREACH     0x00000200      /* a foreach loop */
684 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
685 #ifdef USE_ITHREADS
686 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
687                                            has pad offset; if not set,
688                                            iterdata holds GV* */
689 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
690                          == (CXt_LOOP|CXp_PADVAR))
691 #endif
692
693 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
694 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
695                          == CXp_MULTICALL)
696 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
697                          == (CXt_EVAL|CXp_REAL))
698 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
699                          == (CXt_EVAL|CXp_TRYBLOCK))
700 #define CxFOREACH(c)    (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH))      \
701                          == (CXt_LOOP|CXp_FOREACH))
702 #define CxFOREACHDEF(c) (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH|CXp_FOR_DEF))\
703                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
704
705 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
706
707 /* 
708 =head1 "Gimme" Values
709 */
710
711 /*
712 =for apidoc AmU||G_SCALAR
713 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
714 L<perlcall>.
715
716 =for apidoc AmU||G_ARRAY
717 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
718 L<perlcall>.
719
720 =for apidoc AmU||G_VOID
721 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
722
723 =for apidoc AmU||G_DISCARD
724 Indicates that arguments returned from a callback should be discarded.  See
725 L<perlcall>.
726
727 =for apidoc AmU||G_EVAL
728
729 Used to force a Perl C<eval> wrapper around a callback.  See
730 L<perlcall>.
731
732 =for apidoc AmU||G_NOARGS
733
734 Indicates that no arguments are being sent to a callback.  See
735 L<perlcall>.
736
737 =cut
738 */
739
740 #define G_SCALAR        0
741 #define G_ARRAY         1
742 #define G_VOID          128     /* skip this bit when adding flags below */
743 #define G_WANT          (128|1)
744
745 /* extra flags for Perl_call_* routines */
746 #define G_DISCARD       2       /* Call FREETMPS.
747                                    Don't change this without consulting the
748                                    hash actions codes defined in hv.h */
749 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
750 #define G_NOARGS        8       /* Don't construct a @_ array. */
751 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
752 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
753 #define G_METHOD       64       /* Calling method. */
754 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
755                                    fold_constants. */
756
757 /* flag bits for PL_in_eval */
758 #define EVAL_NULL       0       /* not in an eval */
759 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
760 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
761 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
762 #define EVAL_INREQUIRE  8       /* The code is being required. */
763
764 /* Support for switching (stack and block) contexts.
765  * This ensures magic doesn't invalidate local stack and cx pointers.
766  */
767
768 #define PERLSI_UNKNOWN          -1
769 #define PERLSI_UNDEF            0
770 #define PERLSI_MAIN             1
771 #define PERLSI_MAGIC            2
772 #define PERLSI_SORT             3
773 #define PERLSI_SIGNAL           4
774 #define PERLSI_OVERLOAD         5
775 #define PERLSI_DESTROY          6
776 #define PERLSI_WARNHOOK         7
777 #define PERLSI_DIEHOOK          8
778 #define PERLSI_REQUIRE          9
779
780 struct stackinfo {
781     AV *                si_stack;       /* stack for current runlevel */
782     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
783     struct stackinfo *  si_prev;
784     struct stackinfo *  si_next;
785     I32                 si_cxix;        /* current context index */
786     I32                 si_cxmax;       /* maximum allocated index */
787     I32                 si_type;        /* type of runlevel */
788     I32                 si_markoff;     /* offset where markstack begins for us.
789                                          * currently used only with DEBUGGING,
790                                          * but not #ifdef-ed for bincompat */
791 };
792
793 typedef struct stackinfo PERL_SI;
794
795 #define cxstack         (PL_curstackinfo->si_cxstack)
796 #define cxstack_ix      (PL_curstackinfo->si_cxix)
797 #define cxstack_max     (PL_curstackinfo->si_cxmax)
798
799 #ifdef DEBUGGING
800 #  define       SET_MARK_OFFSET \
801     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
802 #else
803 #  define       SET_MARK_OFFSET NOOP
804 #endif
805
806 #define PUSHSTACKi(type) \
807     STMT_START {                                                        \
808         PERL_SI *next = PL_curstackinfo->si_next;                       \
809         if (!next) {                                                    \
810             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
811             next->si_prev = PL_curstackinfo;                            \
812             PL_curstackinfo->si_next = next;                            \
813         }                                                               \
814         next->si_type = type;                                           \
815         next->si_cxix = -1;                                             \
816         AvFILLp(next->si_stack) = 0;                                    \
817         SWITCHSTACK(PL_curstack,next->si_stack);                        \
818         PL_curstackinfo = next;                                         \
819         SET_MARK_OFFSET;                                                \
820     } STMT_END
821
822 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
823
824 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
825  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
826 #define POPSTACK \
827     STMT_START {                                                        \
828         dSP;                                                            \
829         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
830         if (!prev) {                                                    \
831             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
832             my_exit(1);                                                 \
833         }                                                               \
834         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
835         /* don't free prev here, free them all at the END{} */          \
836         PL_curstackinfo = prev;                                         \
837     } STMT_END
838
839 #define POPSTACK_TO(s) \
840     STMT_START {                                                        \
841         while (PL_curstack != s) {                                      \
842             dounwind(-1);                                               \
843             POPSTACK;                                                   \
844         }                                                               \
845     } STMT_END
846
847 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
848 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
849
850 /*
851 =head1 Multicall Functions
852
853 =for apidoc Ams||dMULTICALL
854 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
855
856 =for apidoc Ams||PUSH_MULTICALL
857 Opening bracket for a lightweight callback.
858 See L<perlcall/Lightweight Callbacks>.
859
860 =for apidoc Ams||MULTICALL
861 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
862
863 =for apidoc Ams||POP_MULTICALL
864 Closing bracket for a lightweight callback.
865 See L<perlcall/Lightweight Callbacks>.
866
867 =cut
868 */
869
870 #define dMULTICALL \
871     SV **newsp;                 /* set by POPBLOCK */                   \
872     PERL_CONTEXT *cx;                                                   \
873     CV *multicall_cv;                                                   \
874     OP *multicall_cop;                                                  \
875     bool multicall_oldcatch;                                            \
876     U8 hasargs = 0              /* used by PUSHSUB */
877
878 #define PUSH_MULTICALL(the_cv) \
879     STMT_START {                                                        \
880         CV * const _nOnclAshIngNamE_ = the_cv;                          \
881         CV * const cv = _nOnclAshIngNamE_;                              \
882         AV * const padlist = CvPADLIST(cv);                             \
883         ENTER;                                                          \
884         multicall_oldcatch = CATCH_GET;                                 \
885         SAVETMPS; SAVEVPTR(PL_op);                                      \
886         CATCH_SET(TRUE);                                                \
887         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
888         PUSHSUB(cx);                                                    \
889         if (++CvDEPTH(cv) >= 2) {                                       \
890             PERL_STACK_OVERFLOW_CHECK();                                \
891             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
892         }                                                               \
893         SAVECOMPPAD();                                                  \
894         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
895         multicall_cv = cv;                                              \
896         multicall_cop = CvSTART(cv);                                    \
897     } STMT_END
898
899 #define MULTICALL \
900     STMT_START {                                                        \
901         PL_op = multicall_cop;                                          \
902         CALLRUNOPS(aTHX);                                               \
903     } STMT_END
904
905 #define POP_MULTICALL \
906     STMT_START {                                                        \
907         LEAVESUB(multicall_cv);                                         \
908         CvDEPTH(multicall_cv)--;                                        \
909         POPBLOCK(cx,PL_curpm);                                          \
910         CATCH_SET(multicall_oldcatch);                                  \
911         LEAVE;                                                          \
912     } STMT_END
913
914 /*
915  * Local variables:
916  * c-indentation-style: bsd
917  * c-basic-offset: 4
918  * indent-tabs-mode: t
919  * End:
920  *
921  * ex: set ts=8 sts=4 sw=4 noet:
922  */