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[perl5.git] / scope.h
CommitLineData
d6376244
JH
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
b9d12d37
GS
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
c76ac1ee 40#define SAVEt_DESTRUCTOR_X 30
7766f137 41#define SAVEt_VPTR 31
e8347627 42#define SAVEt_I8 32
354992b1 43#define SAVEt_COMPPAD 33
f4dd75d9 44#define SAVEt_GENERIC_PVREF 34
c3564e5c 45#define SAVEt_PADSV 35
26d9b02f 46#define SAVEt_MORTALIZESV 36
05ec9bb3 47#define SAVEt_SHARED_PVREF 37
79072805 48
b03c0a3a 49#ifndef SCOPE_SAVES_SIGNAL_MASK
1b266415 50#define SCOPE_SAVES_SIGNAL_MASK 0
b03c0a3a
NIS
51#endif
52
3280af22
NIS
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))
c76ac1ee 59#define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
3280af22
NIS
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)
c76ac1ee 65#define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
8990e307 66
954c1994 67/*
ccfc67b7
JH
68=head1 Callback Functions
69
954c1994
GS
70=for apidoc Ams||SAVETMPS
71Opening bracket for temporaries on a callback. See C<FREETMPS> and
72L<perlcall>.
73
74=for apidoc Ams||FREETMPS
75Closing bracket for temporaries on a callback. See C<SAVETMPS> and
76L<perlcall>.
77
78=for apidoc Ams||ENTER
79Opening bracket on a callback. See C<LEAVE> and L<perlcall>.
80
81=for apidoc Ams||LEAVE
82Closing bracket on a callback. See C<ENTER> and L<perlcall>.
83
84=cut
85*/
86
3280af22
NIS
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()
a0d0e21e 89
f46d017c
GS
90#ifdef DEBUGGING
91#define ENTER \
92 STMT_START { \
93 push_scope(); \
cea2e8a9 94 DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n", \
3280af22 95 PL_scopestack_ix, __FILE__, __LINE__))); \
f46d017c
GS
96 } STMT_END
97#define LEAVE \
98 STMT_START { \
cea2e8a9 99 DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n", \
3280af22 100 PL_scopestack_ix, __FILE__, __LINE__))); \
f46d017c
GS
101 pop_scope(); \
102 } STMT_END
103#else
a0d0e21e
LW
104#define ENTER push_scope()
105#define LEAVE pop_scope()
f46d017c 106#endif
3280af22 107#define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
a0d0e21e 108
55497cff 109/*
b9d12d37 110 * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
55497cff
PP
111 * because these are used for several kinds of pointer values
112 */
e8347627 113#define SAVEI8(i) save_I8(SOFT_CAST(I8*)&(i))
4fdae800
PP
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))
55497cff
PP
119#define SAVESPTR(s) save_sptr((SV**)&(s))
120#define SAVEPPTR(s) save_pptr(SOFT_CAST(char**)&(s))
57b2e452 121#define SAVEVPTR(s) save_vptr((void*)&(s))
c3564e5c 122#define SAVEPADSV(s) save_padsv(s)
55497cff 123#define SAVEFREESV(s) save_freesv((SV*)(s))
26d9b02f 124#define SAVEMORTALIZESV(s) save_mortalizesv((SV*)(s))
55497cff
PP
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))
b9d12d37 128#define SAVEGENERICSV(s) save_generic_svref((SV**)&(s))
f4dd75d9 129#define SAVEGENERICPV(s) save_generic_pvref((char**)&(s))
05ec9bb3 130#define SAVESHAREDPV(s) save_shared_pvref((char**)&(s))
55497cff
PP
131#define SAVEDELETE(h,k,l) \
132 save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
133#define SAVEDESTRUCTOR(f,p) \
c76ac1ee
GS
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))
25eaa213
GS
138
139#define SAVESTACK_POS() \
140 STMT_START { \
141 SSCHECK(2); \
3280af22 142 SSPUSHINT(PL_stack_sp - PL_stack_base); \
25eaa213
GS
143 SSPUSHINT(SAVEt_STACK_POS); \
144 } STMT_END
145
462e5cf6 146#define SAVEOP() save_op()
25eaa213
GS
147
148#define SAVEHINTS() \
149 STMT_START { \
3280af22 150 if (PL_hints & HINT_LOCALIZE_HH) \
25eaa213
GS
151 save_hints(); \
152 else { \
153 SSCHECK(2); \
3280af22 154 SSPUSHINT(PL_hints); \
25eaa213
GS
155 SSPUSHINT(SAVEt_HINTS); \
156 } \
157 } STMT_END
354992b1
GS
158
159#define SAVECOMPPAD() \
160 STMT_START { \
f3548bdc
DM
161 SSCHECK(2); \
162 SSPUSHPTR((SV*)PL_comppad); \
163 SSPUSHINT(SAVEt_COMPPAD); \
354992b1 164 } STMT_END
a9332b4a 165
57843af0 166#ifdef USE_ITHREADS
f4dd75d9 167# define SAVECOPSTASH(c) SAVEPPTR(CopSTASHPV(c))
05ec9bb3 168# define SAVECOPSTASH_FREE(c) SAVESHAREDPV(CopSTASHPV(c))
f4dd75d9 169# define SAVECOPFILE(c) SAVEPPTR(CopFILE(c))
05ec9bb3 170# define SAVECOPFILE_FREE(c) SAVESHAREDPV(CopFILE(c))
57843af0 171#else
f4dd75d9
GS
172# define SAVECOPSTASH(c) SAVESPTR(CopSTASH(c))
173# define SAVECOPSTASH_FREE(c) SAVECOPSTASH(c) /* XXX not refcounted */
174# define SAVECOPFILE(c) SAVESPTR(CopFILEGV(c))
175# define SAVECOPFILE_FREE(c) SAVEGENERICSV(CopFILEGV(c))
57843af0
GS
176#endif
177
f4dd75d9 178#define SAVECOPLINE(c) SAVEI16(CopLINE(c))
57843af0 179
455ece5e
AD
180/* SSNEW() temporarily allocates a specified number of bytes of data on the
181 * savestack. It returns an integer index into the savestack, because a
182 * pointer would get broken if the savestack is moved on reallocation.
183 * SSNEWa() works like SSNEW(), but also aligns the data to the specified
184 * number of bytes. MEM_ALIGNBYTES is perhaps the most useful. The
185 * alignment will be preserved therough savestack reallocation *only* if
186 * realloc returns data aligned to a size divisible by `align'!
187 *
188 * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
189 */
190
f2b2c1a7 191#define SSNEW(size) Perl_save_alloc(aTHX_ (size), 0)
02db2b7b 192#define SSNEWt(n,t) SSNEW((n)*sizeof(t))
f2b2c1a7 193#define SSNEWa(size,align) Perl_save_alloc(aTHX_ (size), \
455ece5e 194 (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
02db2b7b 195#define SSNEWat(n,t,align) SSNEWa((n)*sizeof(t), align)
455ece5e 196
02db2b7b
IZ
197#define SSPTR(off,type) ((type) ((char*)PL_savestack + off))
198#define SSPTRt(off,type) ((type*) ((char*)PL_savestack + off))
455ece5e 199
54310121
PP
200/* A jmpenv packages the state required to perform a proper non-local jump.
201 * Note that there is a start_env initialized when perl starts, and top_env
202 * points to this initially, so top_env should always be non-null.
203 *
204 * Existence of a non-null top_env->je_prev implies it is valid to call
6224f72b
GS
205 * longjmp() at that runlevel (we make sure start_env.je_prev is always
206 * null to ensure this).
54310121
PP
207 *
208 * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
209 * establish a local jmpenv to handle exception traps. Care must be taken
210 * to restore the previous value of je_mustcatch before exiting the
211 * stack frame iff JMPENV_PUSH was not called in that stack frame.
6224f72b 212 * GSAR 97-03-27
54310121
PP
213 */
214
215struct jmpenv {
216 struct jmpenv * je_prev;
312caa8e
CS
217 Sigjmp_buf je_buf; /* only for use if !je_throw */
218 int je_ret; /* last exception thrown */
219 bool je_mustcatch; /* need to call longjmp()? */
14dd3ad8 220#ifdef PERL_FLEXIBLE_EXCEPTIONS
312caa8e 221 void (*je_throw)(int v); /* last for bincompat */
db36c5a1 222 bool je_noset; /* no need for setjmp() */
14dd3ad8 223#endif
1163b5c4 224};
1163b5c4 225
6224f72b 226typedef struct jmpenv JMPENV;
1163b5c4 227
14dd3ad8
GS
228#ifdef OP_IN_REGISTER
229#define OP_REG_TO_MEM PL_opsave = op
230#define OP_MEM_TO_REG op = PL_opsave
231#else
232#define OP_REG_TO_MEM NOOP
233#define OP_MEM_TO_REG NOOP
234#endif
312caa8e
CS
235
236/*
237 * How to build the first jmpenv.
238 *
239 * top_env needs to be non-zero. It points to an area
240 * in which longjmp() stuff is stored, as C callstack
241 * info there at least is thread specific this has to
242 * be per-thread. Otherwise a 'die' in a thread gives
243 * that thread the C stack of last thread to do an eval {}!
244 */
245
246#define JMPENV_BOOTSTRAP \
247 STMT_START { \
14dd3ad8 248 Zero(&PL_start_env, 1, JMPENV); \
312caa8e
CS
249 PL_start_env.je_ret = -1; \
250 PL_start_env.je_mustcatch = TRUE; \
251 PL_top_env = &PL_start_env; \
252 } STMT_END
253
14dd3ad8 254#ifdef PERL_FLEXIBLE_EXCEPTIONS
462e5cf6 255
312caa8e
CS
256/*
257 * These exception-handling macros are split up to
258 * ease integration with C++ exceptions.
259 *
260 * To use C++ try+catch to catch Perl exceptions, an extension author
261 * needs to first write an extern "C" function to throw an appropriate
262 * exception object; typically it will be or contain an integer,
263 * because Perl's internals use integers to track exception types:
264 * extern "C" { static void thrower(int i) { throw i; } }
265 *
266 * Then (as shown below) the author needs to use, not the simple
267 * JMPENV_PUSH, but several of its constitutent macros, to arrange for
268 * the Perl internals to call thrower() rather than longjmp() to
269 * report exceptions:
270 *
271 * dJMPENV;
272 * JMPENV_PUSH_INIT(thrower);
273 * try {
274 * ... stuff that may throw exceptions ...
275 * }
276 * catch (int why) { // or whatever matches thrower()
277 * JMPENV_POST_CATCH;
278 * EXCEPT_SET(why);
279 * switch (why) {
280 * ... // handle various Perl exception codes
281 * }
282 * }
283 * JMPENV_POP; // don't forget this!
284 */
285
14dd3ad8
GS
286/*
287 * Function that catches/throws, and its callback for the
288 * body of protected processing.
289 */
290typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
291typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
292 int *, protect_body_t, ...);
293
db36c5a1
GS
294#define dJMPENV JMPENV cur_env; \
295 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
312caa8e 296
db36c5a1 297#define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
6224f72b 298 STMT_START { \
db36c5a1
GS
299 (ce).je_throw = (THROWFUNC); \
300 (ce).je_ret = -1; \
301 (ce).je_mustcatch = FALSE; \
302 (ce).je_prev = PL_top_env; \
303 PL_top_env = &(ce); \
6224f72b 304 OP_REG_TO_MEM; \
312caa8e 305 } STMT_END
1d651c14 306
f2b2c1a7 307#define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
1d651c14 308
db36c5a1 309#define JMPENV_POST_CATCH_ENV(ce) \
312caa8e 310 STMT_START { \
6224f72b 311 OP_MEM_TO_REG; \
db36c5a1 312 PL_top_env = &(ce); \
6224f72b 313 } STMT_END
312caa8e 314
db36c5a1 315#define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
1d651c14 316
db36c5a1
GS
317#define JMPENV_PUSH_ENV(ce,v) \
318 STMT_START { \
319 if (!(ce).je_noset) { \
14dd3ad8
GS
320 DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
321 ce, PL_top_env)); \
db36c5a1 322 JMPENV_PUSH_INIT_ENV(ce,NULL); \
b03c0a3a 323 EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
db36c5a1
GS
324 (ce).je_noset = 1; \
325 } \
326 else \
327 EXCEPT_SET_ENV(ce,0); \
328 JMPENV_POST_CATCH_ENV(ce); \
329 (v) = EXCEPT_GET_ENV(ce); \
312caa8e
CS
330 } STMT_END
331
f2b2c1a7 332#define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
1d651c14 333
db36c5a1 334#define JMPENV_POP_ENV(ce) \
14dd3ad8
GS
335 STMT_START { \
336 if (PL_top_env == &(ce)) \
337 PL_top_env = (ce).je_prev; \
338 } STMT_END
312caa8e 339
f2b2c1a7 340#define JMPENV_POP JMPENV_POP_ENV(*(JMPENV*)pcur_env)
1d651c14 341
22921e25
CS
342#define JMPENV_JUMP(v) \
343 STMT_START { \
462e5cf6 344 OP_REG_TO_MEM; \
312caa8e
CS
345 if (PL_top_env->je_prev) { \
346 if (PL_top_env->je_throw) \
347 PL_top_env->je_throw(v); \
348 else \
349 PerlProc_longjmp(PL_top_env->je_buf, (v)); \
350 } \
6224f72b 351 if ((v) == 2) \
312caa8e 352 PerlProc_exit(STATUS_NATIVE_EXPORT); \
bf49b057 353 PerlIO_printf(Perl_error_log, "panic: top_env\n"); \
312caa8e 354 PerlProc_exit(1); \
22921e25 355 } STMT_END
312caa8e 356
db36c5a1
GS
357#define EXCEPT_GET_ENV(ce) ((ce).je_ret)
358#define EXCEPT_GET EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
359#define EXCEPT_SET_ENV(ce,v) ((ce).je_ret = (v))
360#define EXCEPT_SET(v) EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
312caa8e 361
14dd3ad8
GS
362#else /* !PERL_FLEXIBLE_EXCEPTIONS */
363
364#define dJMPENV JMPENV cur_env
365
366#define JMPENV_PUSH(v) \
367 STMT_START { \
368 DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
369 &cur_env, PL_top_env)); \
370 cur_env.je_prev = PL_top_env; \
371 OP_REG_TO_MEM; \
b03c0a3a 372 cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK); \
14dd3ad8
GS
373 OP_MEM_TO_REG; \
374 PL_top_env = &cur_env; \
375 cur_env.je_mustcatch = FALSE; \
376 (v) = cur_env.je_ret; \
377 } STMT_END
378
379#define JMPENV_POP \
380 STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
381
382#define JMPENV_JUMP(v) \
383 STMT_START { \
384 OP_REG_TO_MEM; \
385 if (PL_top_env->je_prev) \
386 PerlProc_longjmp(PL_top_env->je_buf, (v)); \
387 if ((v) == 2) \
388 PerlProc_exit(STATUS_NATIVE_EXPORT); \
389 PerlIO_printf(PerlIO_stderr(), "panic: top_env\n"); \
390 PerlProc_exit(1); \
391 } STMT_END
392
393#endif /* PERL_FLEXIBLE_EXCEPTIONS */
394
db36c5a1
GS
395#define CATCH_GET (PL_top_env->je_mustcatch)
396#define CATCH_SET(v) (PL_top_env->je_mustcatch = (v))