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Missed the =head1 additions.
[perl5.git] / scope.h
1 #define SAVEt_ITEM              0
2 #define SAVEt_SV                1
3 #define SAVEt_AV                2
4 #define SAVEt_HV                3
5 #define SAVEt_INT               4
6 #define SAVEt_LONG              5
7 #define SAVEt_I32               6
8 #define SAVEt_IV                7
9 #define SAVEt_SPTR              8
10 #define SAVEt_APTR              9
11 #define SAVEt_HPTR              10
12 #define SAVEt_PPTR              11
13 #define SAVEt_NSTAB             12
14 #define SAVEt_SVREF             13
15 #define SAVEt_GP                14
16 #define SAVEt_FREESV            15
17 #define SAVEt_FREEOP            16
18 #define SAVEt_FREEPV            17
19 #define SAVEt_CLEARSV           18
20 #define SAVEt_DELETE            19
21 #define SAVEt_DESTRUCTOR        20
22 #define SAVEt_REGCONTEXT        21
23 #define SAVEt_STACK_POS         22
24 #define SAVEt_I16               23
25 #define SAVEt_AELEM             24
26 #define SAVEt_HELEM             25
27 #define SAVEt_OP                26
28 #define SAVEt_HINTS             27
29 #define SAVEt_ALLOC             28
30 #define SAVEt_GENERIC_SVREF     29
31 #define SAVEt_DESTRUCTOR_X      30
32 #define SAVEt_VPTR              31
33 #define SAVEt_I8                32
34 #define SAVEt_COMPPAD           33
35 #define SAVEt_GENERIC_PVREF     34
36 #define SAVEt_PADSV             35
37 #define SAVEt_MORTALIZESV       36
38
39 #ifndef SCOPE_SAVES_SIGNAL_MASK
40 #define SCOPE_SAVES_SIGNAL_MASK 0
41 #endif
42
43 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
44 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
45 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
46 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
47 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
48 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
49 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
50 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
51 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
52 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
53 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
54 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
55 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
56
57 /*
58 =head1 Callback Functions
59
60 =for apidoc Ams||SAVETMPS
61 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
62 L<perlcall>.
63
64 =for apidoc Ams||FREETMPS
65 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
66 L<perlcall>.
67
68 =for apidoc Ams||ENTER
69 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
70
71 =for apidoc Ams||LEAVE
72 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
73
74 =cut
75 */
76
77 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
78 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
79
80 #ifdef DEBUGGING
81 #define ENTER                                                   \
82     STMT_START {                                                \
83         push_scope();                                           \
84         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",   \
85                     PL_scopestack_ix, __FILE__, __LINE__)));    \
86     } STMT_END
87 #define LEAVE                                                   \
88     STMT_START {                                                \
89         DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",   \
90                     PL_scopestack_ix, __FILE__, __LINE__)));    \
91         pop_scope();                                            \
92     } STMT_END
93 #else
94 #define ENTER push_scope()
95 #define LEAVE pop_scope()
96 #endif
97 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
98
99 /*
100  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
101  * because these are used for several kinds of pointer values
102  */
103 #define SAVEI8(i)       save_I8(SOFT_CAST(I8*)&(i))
104 #define SAVEI16(i)      save_I16(SOFT_CAST(I16*)&(i))
105 #define SAVEI32(i)      save_I32(SOFT_CAST(I32*)&(i))
106 #define SAVEINT(i)      save_int(SOFT_CAST(int*)&(i))
107 #define SAVEIV(i)       save_iv(SOFT_CAST(IV*)&(i))
108 #define SAVELONG(l)     save_long(SOFT_CAST(long*)&(l))
109 #define SAVESPTR(s)     save_sptr((SV**)&(s))
110 #define SAVEPPTR(s)     save_pptr(SOFT_CAST(char**)&(s))
111 #define SAVEVPTR(s)     save_vptr((void*)&(s))
112 #define SAVEPADSV(s)    save_padsv(s)
113 #define SAVEFREESV(s)   save_freesv((SV*)(s))
114 #define SAVEMORTALIZESV(s)      save_mortalizesv((SV*)(s))
115 #define SAVEFREEOP(o)   save_freeop(SOFT_CAST(OP*)(o))
116 #define SAVEFREEPV(p)   save_freepv(SOFT_CAST(char*)(p))
117 #define SAVECLEARSV(sv) save_clearsv(SOFT_CAST(SV**)&(sv))
118 #define SAVEGENERICSV(s)        save_generic_svref((SV**)&(s))
119 #define SAVEGENERICPV(s)        save_generic_pvref((char**)&(s))
120 #define SAVEDELETE(h,k,l) \
121           save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
122 #define SAVEDESTRUCTOR(f,p) \
123           save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
124
125 #define SAVEDESTRUCTOR_X(f,p) \
126           save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
127
128 #define SAVESTACK_POS() \
129     STMT_START {                                \
130         SSCHECK(2);                             \
131         SSPUSHINT(PL_stack_sp - PL_stack_base); \
132         SSPUSHINT(SAVEt_STACK_POS);             \
133     } STMT_END
134
135 #define SAVEOP()        save_op()
136
137 #define SAVEHINTS() \
138     STMT_START {                                \
139         if (PL_hints & HINT_LOCALIZE_HH)        \
140             save_hints();                       \
141         else {                                  \
142             SSCHECK(2);                         \
143             SSPUSHINT(PL_hints);                \
144             SSPUSHINT(SAVEt_HINTS);             \
145         }                                       \
146     } STMT_END
147
148 #define SAVECOMPPAD() \
149     STMT_START {                                                \
150         if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {   \
151             SSCHECK(2);                                         \
152             SSPUSHPTR((SV*)PL_comppad);                         \
153             SSPUSHINT(SAVEt_COMPPAD);                           \
154         }                                                       \
155         else {                                                  \
156             SAVEVPTR(PL_curpad);                                \
157             SAVESPTR(PL_comppad);                               \
158         }                                                       \
159     } STMT_END
160
161 #ifdef USE_ITHREADS
162 #  define SAVECOPSTASH(c)       SAVEPPTR(CopSTASHPV(c))
163 #  define SAVECOPSTASH_FREE(c)  SAVEGENERICPV(CopSTASHPV(c))
164 #  define SAVECOPFILE(c)        SAVEPPTR(CopFILE(c))
165 #  define SAVECOPFILE_FREE(c)   SAVEGENERICPV(CopFILE(c))
166 #else
167 #  define SAVECOPSTASH(c)       SAVESPTR(CopSTASH(c))
168 #  define SAVECOPSTASH_FREE(c)  SAVECOPSTASH(c) /* XXX not refcounted */
169 #  define SAVECOPFILE(c)        SAVESPTR(CopFILEGV(c))
170 #  define SAVECOPFILE_FREE(c)   SAVEGENERICSV(CopFILEGV(c))
171 #endif
172
173 #define SAVECOPLINE(c)          SAVEI16(CopLINE(c))
174
175 /* SSNEW() temporarily allocates a specified number of bytes of data on the
176  * savestack.  It returns an integer index into the savestack, because a
177  * pointer would get broken if the savestack is moved on reallocation.
178  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
179  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
180  * alignment will be preserved therough savestack reallocation *only* if
181  * realloc returns data aligned to a size divisible by `align'!
182  *
183  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
184  */
185
186 #define SSNEW(size)             Perl_save_alloc(aTHX_ (size), 0)
187 #define SSNEWt(n,t)             SSNEW((n)*sizeof(t))
188 #define SSNEWa(size,align)      Perl_save_alloc(aTHX_ (size), \
189     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
190 #define SSNEWat(n,t,align)      SSNEWa((n)*sizeof(t), align)
191
192 #define SSPTR(off,type)         ((type)  ((char*)PL_savestack + off))
193 #define SSPTRt(off,type)        ((type*) ((char*)PL_savestack + off))
194
195 /* A jmpenv packages the state required to perform a proper non-local jump.
196  * Note that there is a start_env initialized when perl starts, and top_env
197  * points to this initially, so top_env should always be non-null.
198  *
199  * Existence of a non-null top_env->je_prev implies it is valid to call
200  * longjmp() at that runlevel (we make sure start_env.je_prev is always
201  * null to ensure this).
202  *
203  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
204  * establish a local jmpenv to handle exception traps.  Care must be taken
205  * to restore the previous value of je_mustcatch before exiting the
206  * stack frame iff JMPENV_PUSH was not called in that stack frame.
207  * GSAR 97-03-27
208  */
209
210 struct jmpenv {
211     struct jmpenv *     je_prev;
212     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
213     int                 je_ret;         /* last exception thrown */
214     bool                je_mustcatch;   /* need to call longjmp()? */
215 #ifdef PERL_FLEXIBLE_EXCEPTIONS
216     void                (*je_throw)(int v); /* last for bincompat */
217     bool                je_noset;       /* no need for setjmp() */
218 #endif
219 };
220
221 typedef struct jmpenv JMPENV;
222
223 #ifdef OP_IN_REGISTER
224 #define OP_REG_TO_MEM   PL_opsave = op
225 #define OP_MEM_TO_REG   op = PL_opsave
226 #else
227 #define OP_REG_TO_MEM   NOOP
228 #define OP_MEM_TO_REG   NOOP
229 #endif
230
231 /*
232  * How to build the first jmpenv.
233  *
234  * top_env needs to be non-zero. It points to an area
235  * in which longjmp() stuff is stored, as C callstack
236  * info there at least is thread specific this has to
237  * be per-thread. Otherwise a 'die' in a thread gives
238  * that thread the C stack of last thread to do an eval {}!
239  */
240
241 #define JMPENV_BOOTSTRAP \
242     STMT_START {                                \
243         Zero(&PL_start_env, 1, JMPENV);         \
244         PL_start_env.je_ret = -1;               \
245         PL_start_env.je_mustcatch = TRUE;       \
246         PL_top_env = &PL_start_env;             \
247     } STMT_END
248
249 #ifdef PERL_FLEXIBLE_EXCEPTIONS
250
251 /*
252  * These exception-handling macros are split up to
253  * ease integration with C++ exceptions.
254  *
255  * To use C++ try+catch to catch Perl exceptions, an extension author
256  * needs to first write an extern "C" function to throw an appropriate
257  * exception object; typically it will be or contain an integer,
258  * because Perl's internals use integers to track exception types:
259  *    extern "C" { static void thrower(int i) { throw i; } }
260  *
261  * Then (as shown below) the author needs to use, not the simple
262  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
263  * the Perl internals to call thrower() rather than longjmp() to
264  * report exceptions:
265  *
266  *    dJMPENV;
267  *    JMPENV_PUSH_INIT(thrower);
268  *    try {
269  *        ... stuff that may throw exceptions ...
270  *    }
271  *    catch (int why) {  // or whatever matches thrower()
272  *        JMPENV_POST_CATCH;
273  *        EXCEPT_SET(why);
274  *        switch (why) {
275  *          ... // handle various Perl exception codes
276  *        }
277  *    }
278  *    JMPENV_POP;  // don't forget this!
279  */
280
281 /*
282  * Function that catches/throws, and its callback for the
283  *  body of protected processing.
284  */
285 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
286 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
287                                              int *, protect_body_t, ...);
288
289 #define dJMPENV JMPENV cur_env; \
290                 volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
291
292 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
293     STMT_START {                                        \
294         (ce).je_throw = (THROWFUNC);                    \
295         (ce).je_ret = -1;                               \
296         (ce).je_mustcatch = FALSE;                      \
297         (ce).je_prev = PL_top_env;                      \
298         PL_top_env = &(ce);                             \
299         OP_REG_TO_MEM;                                  \
300     } STMT_END
301
302 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
303
304 #define JMPENV_POST_CATCH_ENV(ce) \
305     STMT_START {                                        \
306         OP_MEM_TO_REG;                                  \
307         PL_top_env = &(ce);                             \
308     } STMT_END
309
310 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
311
312 #define JMPENV_PUSH_ENV(ce,v) \
313     STMT_START {                                                \
314         if (!(ce).je_noset) {                                   \
315             DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n", \
316                              ce, PL_top_env));                  \
317             JMPENV_PUSH_INIT_ENV(ce,NULL);                      \
318             EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, SCOPE_SAVES_SIGNAL_MASK));\
319             (ce).je_noset = 1;                                  \
320         }                                                       \
321         else                                                    \
322             EXCEPT_SET_ENV(ce,0);                               \
323         JMPENV_POST_CATCH_ENV(ce);                              \
324         (v) = EXCEPT_GET_ENV(ce);                               \
325     } STMT_END
326
327 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
328
329 #define JMPENV_POP_ENV(ce) \
330     STMT_START {                                                \
331         if (PL_top_env == &(ce))                                \
332             PL_top_env = (ce).je_prev;                          \
333     } STMT_END
334
335 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
336
337 #define JMPENV_JUMP(v) \
338     STMT_START {                                                \
339         OP_REG_TO_MEM;                                          \
340         if (PL_top_env->je_prev) {                              \
341             if (PL_top_env->je_throw)                           \
342                 PL_top_env->je_throw(v);                        \
343             else                                                \
344                 PerlProc_longjmp(PL_top_env->je_buf, (v));      \
345         }                                                       \
346         if ((v) == 2)                                           \
347             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
348         PerlIO_printf(Perl_error_log, "panic: top_env\n");      \
349         PerlProc_exit(1);                                       \
350     } STMT_END
351
352 #define EXCEPT_GET_ENV(ce)      ((ce).je_ret)
353 #define EXCEPT_GET              EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
354 #define EXCEPT_SET_ENV(ce,v)    ((ce).je_ret = (v))
355 #define EXCEPT_SET(v)           EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
356
357 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
358
359 #define dJMPENV         JMPENV cur_env
360
361 #define JMPENV_PUSH(v) \
362     STMT_START {                                                        \
363         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
364                          &cur_env, PL_top_env));                        \
365         cur_env.je_prev = PL_top_env;                                   \
366         OP_REG_TO_MEM;                                                  \
367         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
368         OP_MEM_TO_REG;                                                  \
369         PL_top_env = &cur_env;                                          \
370         cur_env.je_mustcatch = FALSE;                                   \
371         (v) = cur_env.je_ret;                                           \
372     } STMT_END
373
374 #define JMPENV_POP \
375     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
376
377 #define JMPENV_JUMP(v) \
378     STMT_START {                                                \
379         OP_REG_TO_MEM;                                          \
380         if (PL_top_env->je_prev)                                \
381             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
382         if ((v) == 2)                                           \
383             PerlProc_exit(STATUS_NATIVE_EXPORT);                \
384         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
385         PerlProc_exit(1);                                       \
386     } STMT_END
387
388 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
389
390 #define CATCH_GET               (PL_top_env->je_mustcatch)
391 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))