Re: [patch] IO::Socket::INET Broadcast patch
[perl.git] / scope.h
1 /*    scope.h
2  *
3  *    Copyright (c) 1997-2002, Larry Wall
4  *
5  *    You may distribute under the terms of either the GNU General Public
6  *    License or the Artistic License, as specified in the README file.
7  *
8  */
9
10 #define SAVEt_ITEM              0
11 #define SAVEt_SV                1
12 #define SAVEt_AV                2
13 #define SAVEt_HV                3
14 #define SAVEt_INT               4
15 #define SAVEt_LONG              5
16 #define SAVEt_I32               6
17 #define SAVEt_IV                7
18 #define SAVEt_SPTR              8
19 #define SAVEt_APTR              9
20 #define SAVEt_HPTR              10
21 #define SAVEt_PPTR              11
22 #define SAVEt_NSTAB             12
23 #define SAVEt_SVREF             13
24 #define SAVEt_GP                14
25 #define SAVEt_FREESV            15
26 #define SAVEt_FREEOP            16
27 #define SAVEt_FREEPV            17
28 #define SAVEt_CLEARSV           18
29 #define SAVEt_DELETE            19
30 #define SAVEt_DESTRUCTOR        20
31 #define SAVEt_REGCONTEXT        21
32 #define SAVEt_STACK_POS         22
33 #define SAVEt_I16               23
34 #define SAVEt_AELEM             24
35 #define SAVEt_HELEM             25
36 #define SAVEt_OP                26
37 #define SAVEt_HINTS             27
38 #define SAVEt_ALLOC             28
39 #define SAVEt_GENERIC_SVREF     29
40 #define SAVEt_DESTRUCTOR_X      30
41 #define SAVEt_VPTR              31
42 #define SAVEt_I8                32
43 #define SAVEt_COMPPAD           33
44 #define SAVEt_GENERIC_PVREF     34
45 #define SAVEt_PADSV             35
46 #define SAVEt_MORTALIZESV       36
47 #define SAVEt_SHARED_PVREF      37
48
49 #ifndef SCOPE_SAVES_SIGNAL_MASK
50 #define SCOPE_SAVES_SIGNAL_MASK 0
51 #endif
52
53 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
54 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
55 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
56 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
57 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
58 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
59 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
60 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
61 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
62 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
63 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
64 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
65 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
66
67 /*
68 =head1 Callback Functions
69
70 =for apidoc Ams||SAVETMPS
71 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
72 L<perlcall>.
73
74 =for apidoc Ams||FREETMPS
75 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
76 L<perlcall>.
77
78 =for apidoc Ams||ENTER
79 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
80
81 =for apidoc Ams||LEAVE
82 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
83
84 =cut
85 */
86
87 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
88 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
89
90 #ifdef DEBUGGING
91 #define ENTER                                                   \
92     STMT_START {                                                \
93         push_scope();                                           \
94         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",   \
95                     PL_scopestack_ix, __FILE__, __LINE__)));    \
96     } STMT_END
97 #define LEAVE                                                   \
98     STMT_START {                                                \
99         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",   \
100                     PL_scopestack_ix, __FILE__, __LINE__)));    \
101         pop_scope();                                            \
102     } STMT_END
103 #else
104 #define ENTER push_scope()
105 #define LEAVE pop_scope()
106 #endif
107 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
108
109 /*
110  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
111  * because these are used for several kinds of pointer values
112  */
113 #define SAVEI8(i)       save_I8(SOFT_CAST(I8*)&(i))
114 #define SAVEI16(i)      save_I16(SOFT_CAST(I16*)&(i))
115 #define SAVEI32(i)      save_I32(SOFT_CAST(I32*)&(i))
116 #define SAVEINT(i)      save_int(SOFT_CAST(int*)&(i))
117 #define SAVEIV(i)       save_iv(SOFT_CAST(IV*)&(i))
118 #define SAVELONG(l)     save_long(SOFT_CAST(long*)&(l))
119 #define SAVESPTR(s)     save_sptr((SV**)&(s))
120 #define SAVEPPTR(s)     save_pptr(SOFT_CAST(char**)&(s))
121 #define SAVEVPTR(s)     save_vptr((void*)&(s))
122 #define SAVEPADSV(s)    save_padsv(s)
123 #define SAVEFREESV(s)   save_freesv((SV*)(s))
124 #define SAVEMORTALIZESV(s)      save_mortalizesv((SV*)(s))
125 #define SAVEFREEOP(o)   save_freeop(SOFT_CAST(OP*)(o))
126 #define SAVEFREEPV(p)   save_freepv(SOFT_CAST(char*)(p))
127 #define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
128 #define SAVEGENERICSV(s)        save_generic_svref((SV**)&(s))
129 #define SAVEGENERICPV(s)        save_generic_pvref((char**)&(s))
130 #define SAVESHAREDPV(s)         save_shared_pvref((char**)&(s))
131 #define SAVEDELETE(h,k,l) \
132           save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
133 #define SAVEDESTRUCTOR(f,p) \
134           save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
135
136 #define SAVEDESTRUCTOR_X(f,p) \
137           save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
138
139 #define SAVESTACK_POS() \
140     STMT_START {                                \
141         SSCHECK(2);                             \
142         SSPUSHINT(PL_stack_sp - PL_stack_base); \
143         SSPUSHINT(SAVEt_STACK_POS);             \
144     } STMT_END
145
146 #define SAVEOP()        save_op()
147
148 #define SAVEHINTS() \
149     STMT_START {                                \
150         if (PL_hints & HINT_LOCALIZE_HH)        \
151             save_hints();                       \
152         else {                                  \
153             SSCHECK(2);                         \
154             SSPUSHINT(PL_hints);                \
155             SSPUSHINT(SAVEt_HINTS);             \
156         }                                       \
157     } STMT_END
158
159 #define SAVECOMPPAD() \
160     STMT_START {                                                \
161         if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {   \
162             SSCHECK(2);                                         \
163             SSPUSHPTR((SV*)PL_comppad);                         \
164             SSPUSHINT(SAVEt_COMPPAD);                           \
165         }                                                       \
166         else {                                                  \
167             SAVEVPTR(PL_curpad);                                \
168             SAVESPTR(PL_comppad);                               \
169         }                                                       \
170     } STMT_END
171
172 #ifdef USE_ITHREADS
173 #  define SAVECOPSTASH(c)       SAVEPPTR(CopSTASHPV(c))
174 #  define SAVECOPSTASH_FREE(c)  SAVESHAREDPV(CopSTASHPV(c))
175 #  define SAVECOPFILE(c)        SAVEPPTR(CopFILE(c))
176 #  define SAVECOPFILE_FREE(c)   SAVESHAREDPV(CopFILE(c))
177 #else
178 #  define SAVECOPSTASH(c)       SAVESPTR(CopSTASH(c))
179 #  define SAVECOPSTASH_FREE(c)  SAVECOPSTASH(c) /* XXX not refcounted */
180 #  define SAVECOPFILE(c)        SAVESPTR(CopFILEGV(c))
181 #  define SAVECOPFILE_FREE(c)   SAVEGENERICSV(CopFILEGV(c))
182 #endif
183
184 #define SAVECOPLINE(c)          SAVEI16(CopLINE(c))
185
186 /* SSNEW() temporarily allocates a specified number of bytes of data on the
187  * savestack.  It returns an integer index into the savestack, because a
188  * pointer would get broken if the savestack is moved on reallocation.
189  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
190  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
191  * alignment will be preserved therough savestack reallocation *only* if
192  * realloc returns data aligned to a size divisible by `align'!
193  *
194  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
195  */
196
197 #define SSNEW(size)             Perl_save_alloc(aTHX_ (size), 0)
198 #define SSNEWt(n,t)             SSNEW((n)*sizeof(t))
199 #define SSNEWa(size,align)      Perl_save_alloc(aTHX_ (size), \
200     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
201 #define SSNEWat(n,t,align)      SSNEWa((n)*sizeof(t), align)
202
203 #define SSPTR(off,type)         ((type)  ((char*)PL_savestack + off))
204 #define SSPTRt(off,type)        ((type*) ((char*)PL_savestack + off))
205
206 /* A jmpenv packages the state required to perform a proper non-local jump.
207  * Note that there is a start_env initialized when perl starts, and top_env
208  * points to this initially, so top_env should always be non-null.
209  *
210  * Existence of a non-null top_env->je_prev implies it is valid to call
211  * longjmp() at that runlevel (we make sure start_env.je_prev is always
212  * null to ensure this).
213  *
214  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
215  * establish a local jmpenv to handle exception traps.  Care must be taken
216  * to restore the previous value of je_mustcatch before exiting the
217  * stack frame iff JMPENV_PUSH was not called in that stack frame.
218  * GSAR 97-03-27
219  */
220
221 struct jmpenv {
222     struct jmpenv *     je_prev;
223     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
224     int                 je_ret;         /* last exception thrown */
225     bool                je_mustcatch;   /* need to call longjmp()? */
226 #ifdef PERL_FLEXIBLE_EXCEPTIONS
227     void                (*je_throw)(int v); /* last for bincompat */
228     bool                je_noset;       /* no need for setjmp() */
229 #endif
230 };
231
232 typedef struct jmpenv JMPENV;
233
234 #ifdef OP_IN_REGISTER
235 #define OP_REG_TO_MEM   PL_opsave = op
236 #define OP_MEM_TO_REG   op = PL_opsave
237 #else
238 #define OP_REG_TO_MEM   NOOP
239 #define OP_MEM_TO_REG   NOOP
240 #endif
241
242 /*
243  * How to build the first jmpenv.
244  *
245  * top_env needs to be non-zero. It points to an area
246  * in which longjmp() stuff is stored, as C callstack
247  * info there at least is thread specific this has to
248  * be per-thread. Otherwise a 'die' in a thread gives
249  * that thread the C stack of last thread to do an eval {}!
250  */
251
252 #define JMPENV_BOOTSTRAP \
253     STMT_START {                                \
254         Zero(&PL_start_env, 1, JMPENV);         \
255         PL_start_env.je_ret = -1;               \
256         PL_start_env.je_mustcatch = TRUE;       \
257         PL_top_env = &PL_start_env;             \
258     } STMT_END
259
260 #ifdef PERL_FLEXIBLE_EXCEPTIONS
261
262 /*
263  * These exception-handling macros are split up to
264  * ease integration with C++ exceptions.
265  *
266  * To use C++ try+catch to catch Perl exceptions, an extension author
267  * needs to first write an extern "C" function to throw an appropriate
268  * exception object; typically it will be or contain an integer,
269  * because Perl's internals use integers to track exception types:
270  *    extern "C" { static void thrower(int i) { throw i; } }
271  *
272  * Then (as shown below) the author needs to use, not the simple
273  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
274  * the Perl internals to call thrower() rather than longjmp() to
275  * report exceptions:
276  *
277  *    dJMPENV;
278  *    JMPENV_PUSH_INIT(thrower);
279  *    try {
280  *        ... stuff that may throw exceptions ...
281  *    }
282  *    catch (int why) {  // or whatever matches thrower()
283  *        JMPENV_POST_CATCH;
284  *        EXCEPT_SET(why);
285  *        switch (why) {
286  *          ... // handle various Perl exception codes
287  *        }
288  *    }
289  *    JMPENV_POP;  // don't forget this!
290  */
291
292 /*
293  * Function that catches/throws, and its callback for the
294  *  body of protected processing.
295  */
296 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
297 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
298                                              int *, protect_body_t, ...);
299
300 #define dJMPENV JMPENV cur_env; \
301                 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
302
303 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
304     STMT_START {                                        \
305         (ce).je_throw = (THROWFUNC);                    \
306         (ce).je_ret = -1;                               \
307         (ce).je_mustcatch = FALSE;                      \
308         (ce).je_prev = PL_top_env;                      \
309         PL_top_env = &(ce);                             \
310         OP_REG_TO_MEM;                                  \
311     } STMT_END
312
313 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
314
315 #define JMPENV_POST_CATCH_ENV(ce) \
316     STMT_START {                                        \
317         OP_MEM_TO_REG;                                  \
318         PL_top_env = &(ce);                             \
319     } STMT_END
320
321 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
322
323 #define JMPENV_PUSH_ENV(ce,v) \
324     STMT_START {                                                \
325         if (!(ce).je_noset) {                                   \
326             DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
327                              ce, PL_top_env));                  \
328             JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
329             EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
330             (ce).je_noset = 1;                                  \
331         }                                                       \
332         else                                                    \
333             EXCEPT_SET_ENV(ce,0);                               \
334         JMPENV_POST_CATCH_ENV(ce);                              \
335         (v) = EXCEPT_GET_ENV(ce);                               \
336     } STMT_END
337
338 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
339
340 #define JMPENV_POP_ENV(ce) \
341     STMT_START {                                                \
342         if (PL_top_env == &(ce))                                \
343             PL_top_env = (ce).je_prev;                          \
344     } STMT_END
345
346 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
347
348 #define JMPENV_JUMP(v) \
349     STMT_START {                                                \
350         OP_REG_TO_MEM;                                          \
351         if (PL_top_env->je_prev) {                              \
352             if (PL_top_env->je_throw)                           \
353                 PL_top_env->je_throw(v);                        \
354             else                                                \
355                 PerlProc_longjmp(PL_top_env->je_buf, (v));      \
356         }                                                       \
357         if ((v) == 2)                                           \
358             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
359         PerlIO_printf(Perl_error_log, "panic: top_env\n");      \
360         PerlProc_exit(1);                                       \
361     } STMT_END
362
363 #define EXCEPT_GET_ENV(ce)      ((ce).je_ret)
364 #define EXCEPT_GET              EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
365 #define EXCEPT_SET_ENV(ce,v)    ((ce).je_ret = (v))
366 #define EXCEPT_SET(v)           EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
367
368 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
369
370 #define dJMPENV         JMPENV cur_env
371
372 #define JMPENV_PUSH(v) \
373     STMT_START {                                                        \
374         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
375                          &cur_env, PL_top_env));                        \
376         cur_env.je_prev = PL_top_env;                                   \
377         OP_REG_TO_MEM;                                                  \
378         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
379         OP_MEM_TO_REG;                                                  \
380         PL_top_env = &cur_env;                                          \
381         cur_env.je_mustcatch = FALSE;                                   \
382         (v) = cur_env.je_ret;                                           \
383     } STMT_END
384
385 #define JMPENV_POP \
386     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
387
388 #define JMPENV_JUMP(v) \
389     STMT_START {                                                \
390         OP_REG_TO_MEM;                                          \
391         if (PL_top_env->je_prev)                                \
392             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
393         if ((v) == 2)                                           \
394             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
395         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
396         PerlProc_exit(1);                                       \
397     } STMT_END
398
399 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
400
401 #define CATCH_GET               (PL_top_env->je_mustcatch)
402 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))