Set the legacy process name with prctl() on assignment to $0 on Linux
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the two ops OP_NEXTSTATE and OP_DBSTATE,
10  * that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a PL_start_env initialized when perl starts, and
18  * PL_top_env points to this initially, so PL_top_env should always be
19  * non-null.
20  *
21  * Existence of a non-null PL_top_env->je_prev implies it is valid to call
22  * longjmp() at that runlevel (we make sure PL_start_env.je_prev is always
23  * null to ensure this).
24  *
25  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
26  * establish a local jmpenv to handle exception traps.  Care must be taken
27  * to restore the previous value of je_mustcatch before exiting the
28  * stack frame iff JMPENV_PUSH was not called in that stack frame.
29  * GSAR 97-03-27
30  */
31
32 struct jmpenv {
33     struct jmpenv *     je_prev;
34     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
35     int                 je_ret;         /* last exception thrown */
36     bool                je_mustcatch;   /* need to call longjmp()? */
37 };
38
39 typedef struct jmpenv JMPENV;
40
41 #ifdef OP_IN_REGISTER
42 #define OP_REG_TO_MEM   PL_opsave = op
43 #define OP_MEM_TO_REG   op = PL_opsave
44 #else
45 #define OP_REG_TO_MEM   NOOP
46 #define OP_MEM_TO_REG   NOOP
47 #endif
48
49 /*
50  * How to build the first jmpenv.
51  *
52  * top_env needs to be non-zero. It points to an area
53  * in which longjmp() stuff is stored, as C callstack
54  * info there at least is thread specific this has to
55  * be per-thread. Otherwise a 'die' in a thread gives
56  * that thread the C stack of last thread to do an eval {}!
57  */
58
59 #define JMPENV_BOOTSTRAP \
60     STMT_START {                                \
61         Zero(&PL_start_env, 1, JMPENV);         \
62         PL_start_env.je_ret = -1;               \
63         PL_start_env.je_mustcatch = TRUE;       \
64         PL_top_env = &PL_start_env;             \
65     } STMT_END
66
67 /*
68  *   PERL_FLEXIBLE_EXCEPTIONS
69  * 
70  * All the flexible exceptions code has been removed.
71  * See the following threads for details:
72  *
73  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
74  * 
75  * Joshua's original patches (which weren't applied) and discussion:
76  * 
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
82  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
83  * 
84  * Chip's reworked patch and discussion:
85  * 
86  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
87  * 
88  * The flaw in these patches (which went unnoticed at the time) was
89  * that they moved some code that could potentially die() out of the
90  * region protected by the setjmp()s.  This caused exceptions within
91  * END blocks and such to not be handled by the correct setjmp().
92  * 
93  * The original patches that introduces flexible exceptions were:
94  *
95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
96  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
97  */
98
99 #define dJMPENV         JMPENV cur_env
100
101 #define JMPENV_PUSH(v) \
102     STMT_START {                                                        \
103         DEBUG_l({                                                       \
104             int i = 0; JMPENV *p = PL_top_env;                          \
105             while (p) { i++; p = p->je_prev; }                          \
106             Perl_deb(aTHX_ "JUMPENV_PUSH level=%d at %s:%d\n",          \
107                          i,  __FILE__, __LINE__);})                     \
108         cur_env.je_prev = PL_top_env;                                   \
109         OP_REG_TO_MEM;                                                  \
110         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
111         OP_MEM_TO_REG;                                                  \
112         PL_top_env = &cur_env;                                          \
113         cur_env.je_mustcatch = FALSE;                                   \
114         (v) = cur_env.je_ret;                                           \
115     } STMT_END
116
117 #define JMPENV_POP \
118     STMT_START {                                                        \
119         DEBUG_l({                                                       \
120             int i = -1; JMPENV *p = PL_top_env;                         \
121             while (p) { i++; p = p->je_prev; }                          \
122             Perl_deb(aTHX_ "JUMPENV_POP level=%d at %s:%d\n",           \
123                          i, __FILE__, __LINE__);})                      \
124         assert(PL_top_env == &cur_env);                                 \
125         PL_top_env = cur_env.je_prev;                                   \
126     } STMT_END
127
128 #define JMPENV_JUMP(v) \
129     STMT_START {                                                \
130         DEBUG_l({                                               \
131             int i = -1; JMPENV *p = PL_top_env;                 \
132             while (p) { i++; p = p->je_prev; }                  \
133             Perl_deb(aTHX_ "JUMPENV_JUMP(%d) level=%d at %s:%d\n", \
134                          (int)v, i, __FILE__, __LINE__);})      \
135         OP_REG_TO_MEM;                                          \
136         if (PL_top_env->je_prev)                                \
137             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
138         if ((v) == 2)                                           \
139             PerlProc_exit(STATUS_EXIT);                         \
140         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
141         PerlProc_exit(1);                                       \
142     } STMT_END
143
144 #define CATCH_GET               (PL_top_env->je_mustcatch)
145 #define CATCH_SET(v) \
146     STMT_START {                                                        \
147         DEBUG_l(                                                        \
148             Perl_deb(aTHX_                                              \
149                 "JUMPLEVEL set catch %d => %d (for %p) at %s:%d\n",     \
150                  PL_top_env->je_mustcatch, v, (void*)PL_top_env,        \
151                  __FILE__, __LINE__);)                                  \
152         PL_top_env->je_mustcatch = (v);                                 \
153     } STMT_END
154
155
156 #include "mydtrace.h"
157
158 struct cop {
159     BASEOP
160     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
161        an exact multiple of 8 bytes to save structure padding.  */
162     line_t      cop_line;       /* line # of this command */
163     /* label for this construct is now stored in cop_hints_hash */
164 #ifdef USE_ITHREADS
165     char *      cop_stashpv;    /* package line was compiled in */
166     char *      cop_file;       /* file name the following line # is from */
167 #else
168     HV *        cop_stash;      /* package line was compiled in */
169     GV *        cop_filegv;     /* file the following line # is from */
170 #endif
171     U32         cop_hints;      /* hints bits from pragmata */
172     U32         cop_seq;        /* parse sequence number */
173     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
174     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
175     /* compile time state of %^H.  See the comment in op.c for how this is
176        used to recreate a hash to return from caller.  */
177     struct refcounted_he * cop_hints_hash;
178 };
179
180 #ifdef USE_ITHREADS
181 #  define CopFILE(c)            ((c)->cop_file)
182 #  define CopFILEGV(c)          (CopFILE(c) \
183                                  ? gv_fetchfile(CopFILE(c)) : NULL)
184                                  
185 #  ifdef NETWARE
186 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
187 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
188 #  else
189 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
190 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
191 #  endif
192
193 #  define CopFILESV(c)          (CopFILE(c) \
194                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
195 #  define CopFILEAV(c)          (CopFILE(c) \
196                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
197 #  ifdef DEBUGGING
198 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
199                                    GvAV(gv_fetchfile(CopFILE(c))))
200 #  else
201 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
202 #  endif
203 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
204
205 #  ifdef NETWARE
206 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
207 #  else
208 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
209 #  endif
210
211 #  define CopSTASH(c)           (CopSTASHPV(c) \
212                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
213 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
214 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
215 #  ifdef NETWARE
216 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
217 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
218 #  else
219 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
220 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
221 #  endif
222 #else
223 #  define CopFILEGV(c)          ((c)->cop_filegv)
224 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
225 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
226 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
227 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
228 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
229 #  ifdef DEBUGGING
230 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
231 #  else
232 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
233 # endif
234 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
235                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
236 #  define CopSTASH(c)           ((c)->cop_stash)
237 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
238 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
239    /* cop_stash is not refcounted */
240 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
241 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
242 #  define CopSTASH_free(c)      
243 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
244
245 #endif /* USE_ITHREADS */
246 #define CopLABEL(c)  Perl_fetch_cop_label(aTHX_ (c)->cop_hints_hash, NULL, NULL)
247 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
248
249 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
250 #define CopLINE(c)              ((c)->cop_line)
251 #define CopLINE_inc(c)          (++CopLINE(c))
252 #define CopLINE_dec(c)          (--CopLINE(c))
253 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
254
255 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
256 #define OutCopFILE(c) CopFILE(c)
257
258 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
259    HINT_ARYBASE is set to indicate this.
260    Setting it is ineficient due to the need to create 2 mortal SVs, but as
261    using $[ is highly discouraged, no sane Perl code will be using it.  */
262 #define CopARYBASE_get(c)       \
263         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
264          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
265                                          "$[", 2, 0, 0))                \
266          : 0)
267 #define CopARYBASE_set(c, b) STMT_START { \
268         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
269             (c)->cop_hints |= HINT_ARYBASE;                             \
270             if ((c) == &PL_compiling) {                                 \
271                 SV *val = newSViv(b);                                   \
272                 (void)hv_stores(GvHV(PL_hintgv), "$[", val);            \
273                 mg_set(val);                                            \
274                 PL_hints |= HINT_ARYBASE;                               \
275             } else {                                                    \
276                 (c)->cop_hints_hash                                     \
277                    = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,  \
278                                         newSVpvs_flags("$[", SVs_TEMP), \
279                                         sv_2mortal(newSViv(b)));        \
280             }                                                           \
281         }                                                               \
282     } STMT_END
283
284 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
285 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
286 #define CopHINTS_set(c, h)      STMT_START {                            \
287                                     (c)->cop_hints = (h);               \
288                                 } STMT_END
289
290 /*
291  * Here we have some enormously heavy (or at least ponderous) wizardry.
292  */
293
294 /* subroutine context */
295 struct block_sub {
296     OP *        retop;  /* op to execute on exit from sub */
297     /* Above here is the same for sub, format and eval.  */
298     CV *        cv;
299     /* Above here is the same for sub and format.  */
300     AV *        savearray;
301     AV *        argarray;
302     I32         olddepth;
303     PAD         *oldcomppad;
304 };
305
306
307 /* format context */
308 struct block_format {
309     OP *        retop;  /* op to execute on exit from sub */
310     /* Above here is the same for sub, format and eval.  */
311     CV *        cv;
312     /* Above here is the same for sub and format.  */
313     GV *        gv;
314     GV *        dfoutgv;
315 };
316
317 /* base for the next two macros. Don't use directly.
318  * Note that the refcnt of the cv is incremented twice;  The CX one is
319  * decremented by LEAVESUB, the other by LEAVE. */
320
321 #define PUSHSUB_BASE(cx)                                                \
322         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
323                 CopFILE((const COP *)CvSTART(cv)),                      \
324                 CopLINE((const COP *)CvSTART(cv)));                     \
325                                                                         \
326         cx->blk_sub.cv = cv;                                            \
327         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
328         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
329         cx->blk_sub.retop = NULL;                                       \
330         if (!CvDEPTH(cv)) {                                             \
331             SvREFCNT_inc_simple_void_NN(cv);                            \
332             SvREFCNT_inc_simple_void_NN(cv);                            \
333             SAVEFREESV(cv);                                             \
334         }
335
336
337 #define PUSHSUB(cx)                                                     \
338         PUSHSUB_BASE(cx)                                                \
339         cx->blk_u16 = PL_op->op_private &                               \
340                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
341
342 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
343 #define PUSHSUB_DB(cx)                                                  \
344         PUSHSUB_BASE(cx)                                                \
345         cx->blk_u16 = 0;
346
347
348 #define PUSHFORMAT(cx, retop)                                           \
349         cx->blk_format.cv = cv;                                         \
350         cx->blk_format.gv = gv;                                         \
351         cx->blk_format.retop = (retop);                                 \
352         cx->blk_format.dfoutgv = PL_defoutgv;                           \
353         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
354
355 #define POP_SAVEARRAY()                                         \
356     STMT_START {                                                        \
357         SvREFCNT_dec(GvAV(PL_defgv));                                   \
358         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
359     } STMT_END
360
361 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
362  * leave any (a fast av_clear(ary), basically) */
363 #define CLEAR_ARGARRAY(ary) \
364     STMT_START {                                                        \
365         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
366         AvARRAY(ary) = AvALLOC(ary);                                    \
367         AvFILLp(ary) = -1;                                              \
368     } STMT_END
369
370 #define POPSUB(cx,sv)                                                   \
371     STMT_START {                                                        \
372         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
373                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
374                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)));     \
375                                                                         \
376         if (CxHASARGS(cx)) {                                            \
377             POP_SAVEARRAY();                                            \
378             /* abandon @_ if it got reified */                          \
379             if (AvREAL(cx->blk_sub.argarray)) {                         \
380                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
381                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
382                 cx->blk_sub.argarray = newAV();                         \
383                 av_extend(cx->blk_sub.argarray, fill);                  \
384                 AvREIFY_only(cx->blk_sub.argarray);                     \
385                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
386             }                                                           \
387             else {                                                      \
388                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
389             }                                                           \
390         }                                                               \
391         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
392         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
393             sv = NULL;                                          \
394     } STMT_END
395
396 #define LEAVESUB(sv)                                                    \
397     STMT_START {                                                        \
398         if (sv)                                                         \
399             SvREFCNT_dec(sv);                                           \
400     } STMT_END
401
402 #define POPFORMAT(cx)                                                   \
403         setdefout(cx->blk_format.dfoutgv);                              \
404         SvREFCNT_dec(cx->blk_format.dfoutgv);
405
406 /* eval context */
407 struct block_eval {
408     OP *        retop;  /* op to execute on exit from eval */
409     /* Above here is the same for sub, format and eval.  */
410     SV *        old_namesv;
411     OP *        old_eval_root;
412     SV *        cur_text;
413     CV *        cv;
414     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
415 };
416
417 /* If we ever need more than 512 op types, change the shift from 7.
418    blku_gimme is actually also only 2 bits, so could be merged with something.
419 */
420
421 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
422 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
423
424 #define PUSHEVAL(cx,n)                                                  \
425     STMT_START {                                                        \
426         assert(!(PL_in_eval & ~0x7F));                                  \
427         assert(!(PL_op->op_type & ~0x1FF));                             \
428         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
429         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
430         cx->blk_eval.old_eval_root = PL_eval_root;                      \
431         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
432         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
433         cx->blk_eval.retop = NULL;                                      \
434         cx->blk_eval.cur_top_env = PL_top_env;                          \
435     } STMT_END
436
437 #define POPEVAL(cx)                                                     \
438     STMT_START {                                                        \
439         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
440         optype = CxOLD_OP_TYPE(cx);                                     \
441         PL_eval_root = cx->blk_eval.old_eval_root;                      \
442         if (cx->blk_eval.old_namesv)                                    \
443             sv_2mortal(cx->blk_eval.old_namesv);                        \
444     } STMT_END
445
446 /* loop context */
447 struct block_loop {
448     I32         resetsp;
449     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
450     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
451         why next_op is conditionally defined below.)  */
452 #ifdef USE_ITHREADS
453     PAD         *oldcomppad; /* Also used for the GV, if targoffset is 0 */
454     /* This is also accesible via cx->blk_loop.my_op->op_targ */
455     PADOFFSET   targoffset;
456 #else
457     OP *        next_op;
458     SV **       itervar;
459 #endif
460     union {
461         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
462             AV * ary; /* use the stack if this is NULL */
463             IV ix;
464         } ary;
465         struct { /* valid if type is LOOP_LAZYIV */
466             IV cur;
467             IV end;
468         } lazyiv;
469         struct { /* valid if type if LOOP_LAZYSV */
470             SV * cur;
471             SV * end; /* maxiumum value (or minimum in reverse) */
472         } lazysv;
473     } state_u;
474 };
475
476 #ifdef USE_ITHREADS
477 #  define CxITERVAR(c)                                                  \
478         ((c)->blk_loop.oldcomppad                                       \
479          ? (CxPADLOOP(c)                                                \
480             ? &CX_CURPAD_SV( (c)->blk_loop, (c)->blk_loop.targoffset )  \
481             : &GvSV((GV*)(c)->blk_loop.oldcomppad))                     \
482          : (SV**)NULL)
483 #  define CX_ITERDATA_SET(cx,idata,o)                                   \
484         if ((cx->blk_loop.targoffset = (o)))                            \
485             CX_CURPAD_SAVE(cx->blk_loop);                               \
486         else                                                            \
487             cx->blk_loop.oldcomppad = (idata);
488 #else
489 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
490 #  define CX_ITERDATA_SET(cx,ivar,o)                                    \
491         cx->blk_loop.itervar = (SV**)(ivar);
492 #endif
493 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
494 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
495 #define CxLVAL(c)       (0 + (c)->blk_u16)
496
497 #ifdef USE_ITHREADS
498 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
499 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
500 #else
501 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
502 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
503 #endif
504
505 #define PUSHLOOP_PLAIN(cx, s)                                           \
506         cx->blk_loop.resetsp = s - PL_stack_base;                       \
507         cx->blk_loop.my_op = cLOOP;                                     \
508         PUSHLOOP_OP_NEXT;                                               \
509         cx->blk_loop.state_u.ary.ary = NULL;                            \
510         cx->blk_loop.state_u.ary.ix = 0;                                \
511         CX_ITERDATA_SET(cx, NULL, 0);
512
513 #define PUSHLOOP_FOR(cx, dat, s, offset)                                \
514         cx->blk_loop.resetsp = s - PL_stack_base;                       \
515         cx->blk_loop.my_op = cLOOP;                                     \
516         PUSHLOOP_OP_NEXT;                                               \
517         cx->blk_loop.state_u.ary.ary = NULL;                            \
518         cx->blk_loop.state_u.ary.ix = 0;                                \
519         CX_ITERDATA_SET(cx, dat, offset);
520
521 #define POPLOOP(cx)                                                     \
522         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
523             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
524             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
525         }                                                               \
526         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
527             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
528
529 /* given/when context */
530 struct block_givwhen {
531         OP *leave_op;
532 };
533
534 #define PUSHGIVEN(cx)                                                   \
535         cx->blk_givwhen.leave_op = cLOGOP->op_other;
536
537 #define PUSHWHEN PUSHGIVEN
538
539 /* context common to subroutines, evals and loops */
540 struct block {
541     U8          blku_type;      /* what kind of context this is */
542     U8          blku_gimme;     /* is this block running in list context? */
543     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
544     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
545     COP *       blku_oldcop;    /* old curcop pointer */
546     I32         blku_oldmarksp; /* mark stack index */
547     I32         blku_oldscopesp;        /* scope stack index */
548     PMOP *      blku_oldpm;     /* values of pattern match vars */
549
550     union {
551         struct block_sub        blku_sub;
552         struct block_format     blku_format;
553         struct block_eval       blku_eval;
554         struct block_loop       blku_loop;
555         struct block_givwhen    blku_givwhen;
556     } blk_u;
557 };
558 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
559 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
560 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
561 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
562 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
563 #define blk_gimme       cx_u.cx_blk.blku_gimme
564 #define blk_u16         cx_u.cx_blk.blku_u16
565 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
566 #define blk_format      cx_u.cx_blk.blk_u.blku_format
567 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
568 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
569 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
570
571 #define DEBUG_CX(action)                                                \
572     DEBUG_l(WITH_THX(                                                   \
573         Perl_deb(aTHX_ "CX %ld %s %s (scope %ld,%ld) at %s:%d\n",       \
574                     (long)cxstack_ix,                                   \
575                     action,                                             \
576                     PL_block_type[CxTYPE(&cxstack[cxstack_ix])],        \
577                     (long)PL_scopestack_ix,                             \
578                     (long)(cxstack[cxstack_ix].blk_oldscopesp),         \
579                     __FILE__, __LINE__)));
580
581 /* Enter a block. */
582 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
583         cx->cx_type             = t,                                    \
584         cx->blk_oldsp           = sp - PL_stack_base,                   \
585         cx->blk_oldcop          = PL_curcop,                            \
586         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
587         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
588         cx->blk_oldpm           = PL_curpm,                             \
589         cx->blk_gimme           = (U8)gimme;                            \
590         DEBUG_CX("PUSH");
591
592 /* Exit a block (RETURN and LAST). */
593 #define POPBLOCK(cx,pm)                                                 \
594         DEBUG_CX("POP");                                                \
595         PERL_ASYNC_CHECK();                                             \
596         cx = &cxstack[cxstack_ix--],                                    \
597         newsp            = PL_stack_base + cx->blk_oldsp,               \
598         PL_curcop        = cx->blk_oldcop,                              \
599         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
600         PL_scopestack_ix = cx->blk_oldscopesp,                          \
601         pm               = cx->blk_oldpm,                               \
602         gimme            = cx->blk_gimme;
603
604 /* Continue a block elsewhere (NEXT and REDO). */
605 #define TOPBLOCK(cx)                                                    \
606         DEBUG_CX("TOP");                                                \
607         cx  = &cxstack[cxstack_ix],                                     \
608         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
609         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
610         PL_scopestack_ix = cx->blk_oldscopesp,                          \
611         PL_curpm         = cx->blk_oldpm;
612
613 /* substitution context */
614 struct subst {
615     U8          sbu_type;       /* what kind of context this is */
616     U8          sbu_rflags;
617     U16         sbu_rxtainted;  /* matches struct block */
618     I32         sbu_iters;
619     I32         sbu_maxiters;
620     I32         sbu_oldsave;
621     char *      sbu_orig;
622     SV *        sbu_dstr;
623     SV *        sbu_targ;
624     char *      sbu_s;
625     char *      sbu_m;
626     char *      sbu_strend;
627     void *      sbu_rxres;
628     REGEXP *    sbu_rx;
629 };
630 #define sb_iters        cx_u.cx_subst.sbu_iters
631 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
632 #define sb_rflags       cx_u.cx_subst.sbu_rflags
633 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
634 #define sb_once         cx_u.cx_subst.sbu_once
635 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
636 #define sb_orig         cx_u.cx_subst.sbu_orig
637 #define sb_dstr         cx_u.cx_subst.sbu_dstr
638 #define sb_targ         cx_u.cx_subst.sbu_targ
639 #define sb_s            cx_u.cx_subst.sbu_s
640 #define sb_m            cx_u.cx_subst.sbu_m
641 #define sb_strend       cx_u.cx_subst.sbu_strend
642 #define sb_rxres        cx_u.cx_subst.sbu_rxres
643 #define sb_rx           cx_u.cx_subst.sbu_rx
644
645 #ifdef PERL_CORE
646 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
647         cx->sb_iters            = iters,                                \
648         cx->sb_maxiters         = maxiters,                             \
649         cx->sb_rflags           = r_flags,                              \
650         cx->sb_oldsave          = oldsave,                              \
651         cx->sb_rxtainted        = rxtainted,                            \
652         cx->sb_orig             = orig,                                 \
653         cx->sb_dstr             = dstr,                                 \
654         cx->sb_targ             = targ,                                 \
655         cx->sb_s                = s,                                    \
656         cx->sb_m                = m,                                    \
657         cx->sb_strend           = strend,                               \
658         cx->sb_rxres            = NULL,                                 \
659         cx->sb_rx               = rx,                                   \
660         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
661         rxres_save(&cx->sb_rxres, rx);                                  \
662         (void)ReREFCNT_inc(rx)
663
664 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
665         rxres_free(&cx->sb_rxres);                                      \
666         ReREFCNT_dec(cx->sb_rx)
667 #endif
668
669 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
670
671 struct context {
672     union {
673         struct block    cx_blk;
674         struct subst    cx_subst;
675     } cx_u;
676 };
677 #define cx_type cx_u.cx_subst.sbu_type
678
679 /* If you re-order these, there is also an array of uppercase names in perl.h
680    and a static array of context names in pp_ctl.c  */
681 #define CXTYPEMASK      0xf
682 #define CXt_NULL        0
683 #define CXt_WHEN        1
684 #define CXt_BLOCK       2
685 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
686    jump table in pp_ctl.c
687    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
688 */
689 #define CXt_GIVEN       3
690 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
691 #define CXt_LOOP_FOR    4
692 #define CXt_LOOP_PLAIN  5
693 #define CXt_LOOP_LAZYSV 6
694 #define CXt_LOOP_LAZYIV 7
695 #define CXt_SUB         8
696 #define CXt_FORMAT      9
697 #define CXt_EVAL       10
698 #define CXt_SUBST      11
699 /* SUBST doesn't feature in all switch statements.  */
700
701 /* private flags for CXt_SUB and CXt_NULL
702    However, this is checked in many places which do not check the type, so
703    this bit needs to be kept clear for most everything else. For reasons I
704    haven't investigated, it can coexist with CXp_FOR_DEF */
705 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
706                                    tear down context on exit). */ 
707
708 /* private flags for CXt_SUB and CXt_FORMAT */
709 #define CXp_HASARGS     0x20
710
711 /* private flags for CXt_EVAL */
712 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
713 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
714
715 /* private flags for CXt_LOOP */
716 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
717 #ifdef USE_ITHREADS
718 #  define CxPADLOOP(c)  ((c)->blk_loop.targoffset)
719 #endif
720
721 /* private flags for CXt_SUBST */
722 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
723
724 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
725 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
726 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
727                          == CXp_MULTICALL)
728 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
729                          == (CXt_EVAL|CXp_REAL))
730 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
731                          == (CXt_EVAL|CXp_TRYBLOCK))
732 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
733 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
734                          && ((c)->cx_type & CXp_FOR_DEF))
735
736 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
737
738 /* 
739 =head1 "Gimme" Values
740 */
741
742 /*
743 =for apidoc AmU||G_SCALAR
744 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
745 L<perlcall>.
746
747 =for apidoc AmU||G_ARRAY
748 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
749 L<perlcall>.
750
751 =for apidoc AmU||G_VOID
752 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
753
754 =for apidoc AmU||G_DISCARD
755 Indicates that arguments returned from a callback should be discarded.  See
756 L<perlcall>.
757
758 =for apidoc AmU||G_EVAL
759
760 Used to force a Perl C<eval> wrapper around a callback.  See
761 L<perlcall>.
762
763 =for apidoc AmU||G_NOARGS
764
765 Indicates that no arguments are being sent to a callback.  See
766 L<perlcall>.
767
768 =cut
769 */
770
771 #define G_SCALAR        2
772 #define G_ARRAY         3
773 #define G_VOID          1
774 #define G_WANT          3
775
776 /* extra flags for Perl_call_* routines */
777 #define G_DISCARD       4       /* Call FREETMPS.
778                                    Don't change this without consulting the
779                                    hash actions codes defined in hv.h */
780 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
781 #define G_NOARGS       16       /* Don't construct a @_ array. */
782 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
783 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
784 #define G_METHOD      128       /* Calling method. */
785 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
786                                    fold_constants. */
787
788 /* flag bits for PL_in_eval */
789 #define EVAL_NULL       0       /* not in an eval */
790 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
791 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
792 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
793 #define EVAL_INREQUIRE  8       /* The code is being required. */
794
795 /* Support for switching (stack and block) contexts.
796  * This ensures magic doesn't invalidate local stack and cx pointers.
797  */
798
799 #define PERLSI_UNKNOWN          -1
800 #define PERLSI_UNDEF            0
801 #define PERLSI_MAIN             1
802 #define PERLSI_MAGIC            2
803 #define PERLSI_SORT             3
804 #define PERLSI_SIGNAL           4
805 #define PERLSI_OVERLOAD         5
806 #define PERLSI_DESTROY          6
807 #define PERLSI_WARNHOOK         7
808 #define PERLSI_DIEHOOK          8
809 #define PERLSI_REQUIRE          9
810
811 struct stackinfo {
812     AV *                si_stack;       /* stack for current runlevel */
813     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
814     struct stackinfo *  si_prev;
815     struct stackinfo *  si_next;
816     I32                 si_cxix;        /* current context index */
817     I32                 si_cxmax;       /* maximum allocated index */
818     I32                 si_type;        /* type of runlevel */
819     I32                 si_markoff;     /* offset where markstack begins for us.
820                                          * currently used only with DEBUGGING,
821                                          * but not #ifdef-ed for bincompat */
822 };
823
824 typedef struct stackinfo PERL_SI;
825
826 #define cxstack         (PL_curstackinfo->si_cxstack)
827 #define cxstack_ix      (PL_curstackinfo->si_cxix)
828 #define cxstack_max     (PL_curstackinfo->si_cxmax)
829
830 #ifdef DEBUGGING
831 #  define       SET_MARK_OFFSET \
832     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
833 #else
834 #  define       SET_MARK_OFFSET NOOP
835 #endif
836
837 #define PUSHSTACKi(type) \
838     STMT_START {                                                        \
839         PERL_SI *next = PL_curstackinfo->si_next;                       \
840         DEBUG_l({                                                       \
841             int i = 0; PERL_SI *p = PL_curstackinfo;                    \
842             while (p) { i++; p = p->si_prev; }                          \
843             Perl_deb(aTHX_ "push STACKINFO %d at %s:%d\n",              \
844                          i, __FILE__, __LINE__);})                      \
845         if (!next) {                                                    \
846             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
847             next->si_prev = PL_curstackinfo;                            \
848             PL_curstackinfo->si_next = next;                            \
849         }                                                               \
850         next->si_type = type;                                           \
851         next->si_cxix = -1;                                             \
852         AvFILLp(next->si_stack) = 0;                                    \
853         SWITCHSTACK(PL_curstack,next->si_stack);                        \
854         PL_curstackinfo = next;                                         \
855         SET_MARK_OFFSET;                                                \
856     } STMT_END
857
858 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
859
860 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
861  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
862 #define POPSTACK \
863     STMT_START {                                                        \
864         dSP;                                                            \
865         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
866         DEBUG_l({                                                       \
867             int i = -1; PERL_SI *p = PL_curstackinfo;                   \
868             while (p) { i++; p = p->si_prev; }                          \
869             Perl_deb(aTHX_ "pop  STACKINFO %d at %s:%d\n",              \
870                          i, __FILE__, __LINE__);})                      \
871         if (!prev) {                                                    \
872             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
873             my_exit(1);                                                 \
874         }                                                               \
875         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
876         /* don't free prev here, free them all at the END{} */          \
877         PL_curstackinfo = prev;                                         \
878     } STMT_END
879
880 #define POPSTACK_TO(s) \
881     STMT_START {                                                        \
882         while (PL_curstack != s) {                                      \
883             dounwind(-1);                                               \
884             POPSTACK;                                                   \
885         }                                                               \
886     } STMT_END
887
888 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
889 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
890
891 /*
892 =head1 Multicall Functions
893
894 =for apidoc Ams||dMULTICALL
895 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
896
897 =for apidoc Ams||PUSH_MULTICALL
898 Opening bracket for a lightweight callback.
899 See L<perlcall/Lightweight Callbacks>.
900
901 =for apidoc Ams||MULTICALL
902 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
903
904 =for apidoc Ams||POP_MULTICALL
905 Closing bracket for a lightweight callback.
906 See L<perlcall/Lightweight Callbacks>.
907
908 =cut
909 */
910
911 #define dMULTICALL \
912     SV **newsp;                 /* set by POPBLOCK */                   \
913     PERL_CONTEXT *cx;                                                   \
914     CV *multicall_cv;                                                   \
915     OP *multicall_cop;                                                  \
916     bool multicall_oldcatch;                                            \
917     U8 hasargs = 0              /* used by PUSHSUB */
918
919 #define PUSH_MULTICALL(the_cv) \
920     STMT_START {                                                        \
921         CV * const _nOnclAshIngNamE_ = the_cv;                          \
922         CV * const cv = _nOnclAshIngNamE_;                              \
923         AV * const padlist = CvPADLIST(cv);                             \
924         ENTER;                                                          \
925         multicall_oldcatch = CATCH_GET;                                 \
926         SAVETMPS; SAVEVPTR(PL_op);                                      \
927         CATCH_SET(TRUE);                                                \
928         PUSHSTACKi(PERLSI_SORT);                                        \
929         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
930         PUSHSUB(cx);                                                    \
931         if (++CvDEPTH(cv) >= 2) {                                       \
932             PERL_STACK_OVERFLOW_CHECK();                                \
933             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
934         }                                                               \
935         SAVECOMPPAD();                                                  \
936         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
937         multicall_cv = cv;                                              \
938         multicall_cop = CvSTART(cv);                                    \
939     } STMT_END
940
941 #define MULTICALL \
942     STMT_START {                                                        \
943         PL_op = multicall_cop;                                          \
944         CALLRUNOPS(aTHX);                                               \
945     } STMT_END
946
947 #define POP_MULTICALL \
948     STMT_START {                                                        \
949         LEAVESUB(multicall_cv);                                         \
950         CvDEPTH(multicall_cv)--;                                        \
951         POPBLOCK(cx,PL_curpm);                                          \
952         POPSTACK;                                                       \
953         CATCH_SET(multicall_oldcatch);                                  \
954         LEAVE;                                                          \
955         SPAGAIN;                                                        \
956     } STMT_END
957
958 /*
959  * Local variables:
960  * c-indentation-style: bsd
961  * c-basic-offset: 4
962  * indent-tabs-mode: t
963  * End:
964  *
965  * ex: set ts=8 sts=4 sw=4 noet:
966  */