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Re: $^CHILD_ERROR_NATIVE issues (with attachment)
[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, 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                          &cur_env, 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                          PL_top_env, cur_env.je_prev));                 \
117         PL_top_env = cur_env.je_prev;                                   \
118     } STMT_END
119
120 #define JMPENV_JUMP(v) \
121     STMT_START {                                                \
122         OP_REG_TO_MEM;                                          \
123         if (PL_top_env->je_prev)                                \
124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
125         if ((v) == 2)                                           \
126             PerlProc_exit(STATUS_EXIT);                         \
127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
128         PerlProc_exit(1);                                       \
129     } STMT_END
130
131 #define CATCH_GET               (PL_top_env->je_mustcatch)
132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
133
134
135
136 struct cop {
137     BASEOP
138     char *      cop_label;      /* label for this construct */
139 #ifdef USE_ITHREADS
140     char *      cop_stashpv;    /* package line was compiled in */
141     char *      cop_file;       /* file name the following line # is from */
142 #else
143     HV *        cop_stash;      /* package line was compiled in */
144     GV *        cop_filegv;     /* file the following line # is from */
145 #endif
146     U32         cop_seq;        /* parse sequence number */
147     I32         cop_arybase;    /* array base this line was compiled with */
148     line_t      cop_line;       /* line # of this command */
149     SV *        cop_warnings;   /* lexical warnings bitmask */
150     SV *        cop_io;         /* lexical IO defaults */
151 };
152
153 #define Nullcop Null(COP*)
154
155 #ifdef USE_ITHREADS
156 #  define CopFILE(c)            ((c)->cop_file)
157 #  define CopFILEGV(c)          (CopFILE(c) \
158                                  ? gv_fetchfile(CopFILE(c)) : Nullgv)
159                                  
160 #  ifdef NETWARE
161 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
162 #  else
163 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
164 #  endif
165
166 #  define CopFILESV(c)          (CopFILE(c) \
167                                  ? GvSV(gv_fetchfile(CopFILE(c))) : Nullsv)
168 #  define CopFILEAV(c)          (CopFILE(c) \
169                                  ? GvAV(gv_fetchfile(CopFILE(c))) : Nullav)
170 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
171
172 #  ifdef NETWARE
173 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : Nullch))
174 #  else
175 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
176 #  endif
177
178 #  define CopSTASH(c)           (CopSTASHPV(c) \
179                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : Nullhv)
180 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : Nullch)
181 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
182 #  ifdef NETWARE
183 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
184 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
185 #  else
186 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
187 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = Nullch))
188 #  endif
189 #else
190 #  define CopFILEGV(c)          ((c)->cop_filegv)
191 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
192 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
193 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : Nullsv)
194 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : Nullav)
195 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : Nullch)
196 #  define CopSTASH(c)           ((c)->cop_stash)
197 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
198 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : Nullch)
199    /* cop_stash is not refcounted */
200 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
201 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
202 #  define CopSTASH_free(c)      
203 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = Nullgv))
204
205 #endif /* USE_ITHREADS */
206
207 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
208 #define CopLINE(c)              ((c)->cop_line)
209 #define CopLINE_inc(c)          (++CopLINE(c))
210 #define CopLINE_dec(c)          (--CopLINE(c))
211 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
212
213 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
214 #ifdef MACOS_TRADITIONAL
215 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
216 #else
217 #  define OutCopFILE(c) CopFILE(c)
218 #endif
219
220 /*
221  * Here we have some enormously heavy (or at least ponderous) wizardry.
222  */
223
224 /* subroutine context */
225 struct block_sub {
226     CV *        cv;
227     GV *        gv;
228     GV *        dfoutgv;
229     AV *        savearray;
230     AV *        argarray;
231     long        olddepth;
232     U8          hasargs;
233     U8          lval;           /* XXX merge lval and hasargs? */
234     PAD         *oldcomppad;
235     OP *        retop;  /* op to execute on exit from sub */
236 };
237
238 /* base for the next two macros. Don't use directly.
239  * Note that the refcnt of the cv is incremented twice;  The CX one is
240  * decremented by LEAVESUB, the other by LEAVE. */
241
242 #define PUSHSUB_BASE(cx)                                                \
243         cx->blk_sub.cv = cv;                                            \
244         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
245         cx->blk_sub.hasargs = hasargs;                                  \
246         cx->blk_sub.retop = Nullop;                                             \
247         if (!CvDEPTH(cv)) {                                             \
248             (void)SvREFCNT_inc(cv);                                     \
249             (void)SvREFCNT_inc(cv);                                     \
250             SAVEFREESV(cv);                                             \
251         }
252
253
254 #define PUSHSUB(cx)                                                     \
255         PUSHSUB_BASE(cx)                                                \
256         cx->blk_sub.lval = PL_op->op_private &                          \
257                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
258
259 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
260 #define PUSHSUB_DB(cx)                                                  \
261         PUSHSUB_BASE(cx)                                                \
262         cx->blk_sub.lval = 0;
263
264
265 #define PUSHFORMAT(cx)                                                  \
266         cx->blk_sub.cv = cv;                                            \
267         cx->blk_sub.gv = gv;                                            \
268         cx->blk_sub.retop = Nullop;                                     \
269         cx->blk_sub.hasargs = 0;                                        \
270         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
271         (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
272
273 #define POP_SAVEARRAY()                                         \
274     STMT_START {                                                        \
275         SvREFCNT_dec(GvAV(PL_defgv));                                   \
276         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
277     } STMT_END
278
279 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
280  * leave any (a fast av_clear(ary), basically) */
281 #define CLEAR_ARGARRAY(ary) \
282     STMT_START {                                                        \
283         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
284         SvPV_set(ary, (char*)AvALLOC(ary));                             \
285         AvFILLp(ary) = -1;                                              \
286     } STMT_END
287
288 #define POPSUB(cx,sv)                                                   \
289     STMT_START {                                                        \
290         if (cx->blk_sub.hasargs) {                                      \
291             POP_SAVEARRAY();                                            \
292             /* abandon @_ if it got reified */                          \
293             if (AvREAL(cx->blk_sub.argarray)) {                         \
294                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
295                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
296                 cx->blk_sub.argarray = newAV();                         \
297                 av_extend(cx->blk_sub.argarray, fill);                  \
298                 AvREIFY_only(cx->blk_sub.argarray);                     \
299                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
300             }                                                           \
301             else {                                                      \
302                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
303             }                                                           \
304         }                                                               \
305         sv = (SV*)cx->blk_sub.cv;                                       \
306         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
307             sv = Nullsv;                                                \
308     } STMT_END
309
310 #define LEAVESUB(sv)                                                    \
311     STMT_START {                                                        \
312         if (sv)                                                         \
313             SvREFCNT_dec(sv);                                           \
314     } STMT_END
315
316 #define POPFORMAT(cx)                                                   \
317         setdefout(cx->blk_sub.dfoutgv);                                 \
318         SvREFCNT_dec(cx->blk_sub.dfoutgv);
319
320 /* eval context */
321 struct block_eval {
322     I32         old_in_eval;
323     I32         old_op_type;
324     SV *        old_namesv;
325     OP *        old_eval_root;
326     SV *        cur_text;
327     CV *        cv;
328     OP *        retop;  /* op to execute on exit from eval */
329     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
330 };
331
332 #define PUSHEVAL(cx,n,fgv)                                              \
333     STMT_START {                                                        \
334         cx->blk_eval.old_in_eval = PL_in_eval;                          \
335         cx->blk_eval.old_op_type = PL_op->op_type;                      \
336         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : Nullsv);          \
337         cx->blk_eval.old_eval_root = PL_eval_root;                      \
338         cx->blk_eval.cur_text = PL_linestr;                             \
339         cx->blk_eval.cv = Nullcv; /* set by doeval(), as applicable */  \
340         cx->blk_eval.retop = Nullop;                                    \
341         cx->blk_eval.cur_top_env = PL_top_env;                          \
342     } STMT_END
343
344 #define POPEVAL(cx)                                                     \
345     STMT_START {                                                        \
346         PL_in_eval = cx->blk_eval.old_in_eval;                          \
347         optype = cx->blk_eval.old_op_type;                              \
348         PL_eval_root = cx->blk_eval.old_eval_root;                      \
349         if (cx->blk_eval.old_namesv)                                    \
350             sv_2mortal(cx->blk_eval.old_namesv);                        \
351     } STMT_END
352
353 /* loop context */
354 struct block_loop {
355     char *      label;
356     I32         resetsp;
357     OP *        redo_op;
358     OP *        next_op;
359     OP *        last_op;
360 #ifdef USE_ITHREADS
361     void *      iterdata;
362     PAD         *oldcomppad;
363 #else
364     SV **       itervar;
365 #endif
366     SV *        itersave;
367     SV *        iterlval;
368     AV *        iterary;
369     IV          iterix;
370     IV          itermax;
371 };
372
373 #ifdef USE_ITHREADS
374 #  define CxITERVAR(c)                                                  \
375         ((c)->blk_loop.iterdata                                         \
376          ? (CxPADLOOP(cx)                                               \
377             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
378                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
379             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
380          : (SV**)NULL)
381 #  define CX_ITERDATA_SET(cx,idata)                                     \
382         CX_CURPAD_SAVE(cx->blk_loop);                                   \
383         if ((cx->blk_loop.iterdata = (idata)))                          \
384             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
385         else                                                            \
386             cx->blk_loop.itersave = Nullsv;
387 #else
388 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
389 #  define CX_ITERDATA_SET(cx,ivar)                                      \
390         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
391             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
392         else                                                            \
393             cx->blk_loop.itersave = Nullsv;
394 #endif
395
396 #define PUSHLOOP(cx, dat, s)                                            \
397         cx->blk_loop.label = PL_curcop->cop_label;                      \
398         cx->blk_loop.resetsp = s - PL_stack_base;                       \
399         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
400         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
401         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
402         cx->blk_loop.iterlval = Nullsv;                                 \
403         cx->blk_loop.iterary = Nullav;                                  \
404         cx->blk_loop.iterix = -1;                                       \
405         CX_ITERDATA_SET(cx,dat);
406
407 #define POPLOOP(cx)                                                     \
408         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
409         if (CxITERVAR(cx)) {                                            \
410             SV **s_v_p = CxITERVAR(cx);                                 \
411             sv_2mortal(*s_v_p);                                         \
412             *s_v_p = cx->blk_loop.itersave;                             \
413         }                                                               \
414         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
415             SvREFCNT_dec(cx->blk_loop.iterary);
416
417 /* context common to subroutines, evals and loops */
418 struct block {
419     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
420     COP *       blku_oldcop;    /* old curcop pointer */
421     I32         blku_oldmarksp; /* mark stack index */
422     I32         blku_oldscopesp;        /* scope stack index */
423     PMOP *      blku_oldpm;     /* values of pattern match vars */
424     U8          blku_gimme;     /* is this block running in list context? */
425
426     union {
427         struct block_sub        blku_sub;
428         struct block_eval       blku_eval;
429         struct block_loop       blku_loop;
430     } blk_u;
431 };
432 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
433 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
434 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
435 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
436 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
437 #define blk_gimme       cx_u.cx_blk.blku_gimme
438 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
439 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
440 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
441
442 /* Enter a block. */
443 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
444         cx->cx_type             = t,                                    \
445         cx->blk_oldsp           = sp - PL_stack_base,                   \
446         cx->blk_oldcop          = PL_curcop,                            \
447         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
448         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
449         cx->blk_oldpm           = PL_curpm,                             \
450         cx->blk_gimme           = (U8)gimme;                            \
451         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
452                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
453
454 /* Exit a block (RETURN and LAST). */
455 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
456         newsp            = PL_stack_base + cx->blk_oldsp,               \
457         PL_curcop        = cx->blk_oldcop,                              \
458         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
459         PL_scopestack_ix = cx->blk_oldscopesp,                          \
460         pm               = cx->blk_oldpm,                               \
461         gimme            = cx->blk_gimme;                               \
462         DEBUG_SCOPE("POPBLOCK");                                        \
463         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
464                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
465
466 /* Continue a block elsewhere (NEXT and REDO). */
467 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
468         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
469         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
470         PL_scopestack_ix = cx->blk_oldscopesp,                          \
471         PL_curpm         = cx->blk_oldpm;                               \
472         DEBUG_SCOPE("TOPBLOCK");
473
474 /* substitution context */
475 struct subst {
476     I32         sbu_iters;
477     I32         sbu_maxiters;
478     I32         sbu_rflags;
479     I32         sbu_oldsave;
480     bool        sbu_once;
481     bool        sbu_rxtainted;
482     char *      sbu_orig;
483     SV *        sbu_dstr;
484     SV *        sbu_targ;
485     char *      sbu_s;
486     char *      sbu_m;
487     char *      sbu_strend;
488     void *      sbu_rxres;
489     REGEXP *    sbu_rx;
490 };
491 #define sb_iters        cx_u.cx_subst.sbu_iters
492 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
493 #define sb_rflags       cx_u.cx_subst.sbu_rflags
494 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
495 #define sb_once         cx_u.cx_subst.sbu_once
496 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
497 #define sb_orig         cx_u.cx_subst.sbu_orig
498 #define sb_dstr         cx_u.cx_subst.sbu_dstr
499 #define sb_targ         cx_u.cx_subst.sbu_targ
500 #define sb_s            cx_u.cx_subst.sbu_s
501 #define sb_m            cx_u.cx_subst.sbu_m
502 #define sb_strend       cx_u.cx_subst.sbu_strend
503 #define sb_rxres        cx_u.cx_subst.sbu_rxres
504 #define sb_rx           cx_u.cx_subst.sbu_rx
505
506 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
507         cx->sb_iters            = iters,                                \
508         cx->sb_maxiters         = maxiters,                             \
509         cx->sb_rflags           = r_flags,                              \
510         cx->sb_oldsave          = oldsave,                              \
511         cx->sb_once             = once,                                 \
512         cx->sb_rxtainted        = rxtainted,                            \
513         cx->sb_orig             = orig,                                 \
514         cx->sb_dstr             = dstr,                                 \
515         cx->sb_targ             = targ,                                 \
516         cx->sb_s                = s,                                    \
517         cx->sb_m                = m,                                    \
518         cx->sb_strend           = strend,                               \
519         cx->sb_rxres            = Null(void*),                          \
520         cx->sb_rx               = rx,                                   \
521         cx->cx_type             = CXt_SUBST;                            \
522         rxres_save(&cx->sb_rxres, rx)
523
524 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
525         rxres_free(&cx->sb_rxres)
526
527 struct context {
528     U32         cx_type;        /* what kind of context this is */
529     union {
530         struct block    cx_blk;
531         struct subst    cx_subst;
532     } cx_u;
533 };
534
535 #define CXTYPEMASK      0xff
536 #define CXt_NULL        0
537 #define CXt_SUB         1
538 #define CXt_EVAL        2
539 #define CXt_LOOP        3
540 #define CXt_SUBST       4
541 #define CXt_BLOCK       5
542 #define CXt_FORMAT      6
543
544 /* private flags for CXt_EVAL */
545 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
546 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
547
548 #ifdef USE_ITHREADS
549 /* private flags for CXt_LOOP */
550 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
551                                            has pad offset; if not set,
552                                            iterdata holds GV* */
553 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
554                          == (CXt_LOOP|CXp_PADVAR))
555 #endif
556
557 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
558 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
559                          == (CXt_EVAL|CXp_REAL))
560 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
561                          == (CXt_EVAL|CXp_TRYBLOCK))
562
563 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
564
565 /* 
566 =head1 "Gimme" Values
567 */
568
569 /*
570 =for apidoc AmU||G_SCALAR
571 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
572 L<perlcall>.
573
574 =for apidoc AmU||G_ARRAY
575 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
576 L<perlcall>.
577
578 =for apidoc AmU||G_VOID
579 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
580
581 =for apidoc AmU||G_DISCARD
582 Indicates that arguments returned from a callback should be discarded.  See
583 L<perlcall>.
584
585 =for apidoc AmU||G_EVAL
586
587 Used to force a Perl C<eval> wrapper around a callback.  See
588 L<perlcall>.
589
590 =for apidoc AmU||G_NOARGS
591
592 Indicates that no arguments are being sent to a callback.  See
593 L<perlcall>.
594
595 =cut
596 */
597
598 #define G_SCALAR        0
599 #define G_ARRAY         1
600 #define G_VOID          128     /* skip this bit when adding flags below */
601
602 /* extra flags for Perl_call_* routines */
603 #define G_DISCARD       2       /* Call FREETMPS. */
604 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
605 #define G_NOARGS        8       /* Don't construct a @_ array. */
606 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
607 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
608 #define G_METHOD       64       /* Calling method. */
609
610 /* flag bits for PL_in_eval */
611 #define EVAL_NULL       0       /* not in an eval */
612 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
613 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
614 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
615 #define EVAL_INREQUIRE  8       /* The code is being required. */
616
617 /* Support for switching (stack and block) contexts.
618  * This ensures magic doesn't invalidate local stack and cx pointers.
619  */
620
621 #define PERLSI_UNKNOWN          -1
622 #define PERLSI_UNDEF            0
623 #define PERLSI_MAIN             1
624 #define PERLSI_MAGIC            2
625 #define PERLSI_SORT             3
626 #define PERLSI_SIGNAL           4
627 #define PERLSI_OVERLOAD         5
628 #define PERLSI_DESTROY          6
629 #define PERLSI_WARNHOOK         7
630 #define PERLSI_DIEHOOK          8
631 #define PERLSI_REQUIRE          9
632
633 struct stackinfo {
634     AV *                si_stack;       /* stack for current runlevel */
635     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
636     I32                 si_cxix;        /* current context index */
637     I32                 si_cxmax;       /* maximum allocated index */
638     I32                 si_type;        /* type of runlevel */
639     struct stackinfo *  si_prev;
640     struct stackinfo *  si_next;
641     I32                 si_markoff;     /* offset where markstack begins for us.
642                                          * currently used only with DEBUGGING,
643                                          * but not #ifdef-ed for bincompat */
644 };
645
646 typedef struct stackinfo PERL_SI;
647
648 #define cxstack         (PL_curstackinfo->si_cxstack)
649 #define cxstack_ix      (PL_curstackinfo->si_cxix)
650 #define cxstack_max     (PL_curstackinfo->si_cxmax)
651
652 #ifdef DEBUGGING
653 #  define       SET_MARK_OFFSET \
654     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
655 #else
656 #  define       SET_MARK_OFFSET NOOP
657 #endif
658
659 #define PUSHSTACKi(type) \
660     STMT_START {                                                        \
661         PERL_SI *next = PL_curstackinfo->si_next;                       \
662         if (!next) {                                                    \
663             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
664             next->si_prev = PL_curstackinfo;                            \
665             PL_curstackinfo->si_next = next;                            \
666         }                                                               \
667         next->si_type = type;                                           \
668         next->si_cxix = -1;                                             \
669         AvFILLp(next->si_stack) = 0;                                    \
670         SWITCHSTACK(PL_curstack,next->si_stack);                        \
671         PL_curstackinfo = next;                                         \
672         SET_MARK_OFFSET;                                                \
673     } STMT_END
674
675 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
676
677 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
678  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
679 #define POPSTACK \
680     STMT_START {                                                        \
681         dSP;                                                            \
682         PERL_SI *prev = PL_curstackinfo->si_prev;                       \
683         if (!prev) {                                                    \
684             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
685             my_exit(1);                                                 \
686         }                                                               \
687         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
688         /* don't free prev here, free them all at the END{} */          \
689         PL_curstackinfo = prev;                                         \
690     } STMT_END
691
692 #define POPSTACK_TO(s) \
693     STMT_START {                                                        \
694         while (PL_curstack != s) {                                      \
695             dounwind(-1);                                               \
696             POPSTACK;                                                   \
697         }                                                               \
698     } STMT_END
699
700 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
701 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
702