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