xref: /openbsd-src/gnu/usr.bin/perl/scope.h (revision e2e5c5d36e4398ba94879f0a31b0307421edcfdb)
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 
36 #define SSCHECK(need) if (PL_savestack_ix + need > PL_savestack_max) savestack_grow()
37 #define SSPUSHINT(i) (PL_savestack[PL_savestack_ix++].any_i32 = (I32)(i))
38 #define SSPUSHLONG(i) (PL_savestack[PL_savestack_ix++].any_long = (long)(i))
39 #define SSPUSHIV(i) (PL_savestack[PL_savestack_ix++].any_iv = (IV)(i))
40 #define SSPUSHPTR(p) (PL_savestack[PL_savestack_ix++].any_ptr = (void*)(p))
41 #define SSPUSHDPTR(p) (PL_savestack[PL_savestack_ix++].any_dptr = (p))
42 #define SSPUSHDXPTR(p) (PL_savestack[PL_savestack_ix++].any_dxptr = (p))
43 #define SSPOPINT (PL_savestack[--PL_savestack_ix].any_i32)
44 #define SSPOPLONG (PL_savestack[--PL_savestack_ix].any_long)
45 #define SSPOPIV (PL_savestack[--PL_savestack_ix].any_iv)
46 #define SSPOPPTR (PL_savestack[--PL_savestack_ix].any_ptr)
47 #define SSPOPDPTR (PL_savestack[--PL_savestack_ix].any_dptr)
48 #define SSPOPDXPTR (PL_savestack[--PL_savestack_ix].any_dxptr)
49 
50 /*
51 =for apidoc Ams||SAVETMPS
52 Opening bracket for temporaries on a callback.  See C<FREETMPS> and
53 L<perlcall>.
54 
55 =for apidoc Ams||FREETMPS
56 Closing bracket for temporaries on a callback.  See C<SAVETMPS> and
57 L<perlcall>.
58 
59 =for apidoc Ams||ENTER
60 Opening bracket on a callback.  See C<LEAVE> and L<perlcall>.
61 
62 =for apidoc Ams||LEAVE
63 Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
64 
65 =cut
66 */
67 
68 #define SAVETMPS save_int((int*)&PL_tmps_floor), PL_tmps_floor = PL_tmps_ix
69 #define FREETMPS if (PL_tmps_ix > PL_tmps_floor) free_tmps()
70 
71 #ifdef DEBUGGING
72 #define ENTER							\
73     STMT_START {						\
74 	push_scope();						\
75 	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "ENTER scope %ld at %s:%d\n",	\
76 		    PL_scopestack_ix, __FILE__, __LINE__)));	\
77     } STMT_END
78 #define LEAVE							\
79     STMT_START {						\
80 	DEBUG_l(WITH_THR(Perl_deb(aTHX_ "LEAVE scope %ld at %s:%d\n",	\
81 		    PL_scopestack_ix, __FILE__, __LINE__)));	\
82 	pop_scope();						\
83     } STMT_END
84 #else
85 #define ENTER push_scope()
86 #define LEAVE pop_scope()
87 #endif
88 #define LEAVE_SCOPE(old) if (PL_savestack_ix > old) leave_scope(old)
89 
90 /*
91  * Not using SOFT_CAST on SAVESPTR, SAVEGENERICSV and SAVEFREESV
92  * because these are used for several kinds of pointer values
93  */
94 #define SAVEI8(i)	save_I8(SOFT_CAST(I8*)&(i))
95 #define SAVEI16(i)	save_I16(SOFT_CAST(I16*)&(i))
96 #define SAVEI32(i)	save_I32(SOFT_CAST(I32*)&(i))
97 #define SAVEINT(i)	save_int(SOFT_CAST(int*)&(i))
98 #define SAVEIV(i)	save_iv(SOFT_CAST(IV*)&(i))
99 #define SAVELONG(l)	save_long(SOFT_CAST(long*)&(l))
100 #define SAVESPTR(s)	save_sptr((SV**)&(s))
101 #define SAVEPPTR(s)	save_pptr(SOFT_CAST(char**)&(s))
102 #define SAVEVPTR(s)	save_vptr((void*)&(s))
103 #define SAVEFREESV(s)	save_freesv((SV*)(s))
104 #define SAVEFREEOP(o)	save_freeop(SOFT_CAST(OP*)(o))
105 #define SAVEFREEPV(p)	save_freepv(SOFT_CAST(char*)(p))
106 #define SAVECLEARSV(sv)	save_clearsv(SOFT_CAST(SV**)&(sv))
107 #define SAVEGENERICSV(s)	save_generic_svref((SV**)&(s))
108 #define SAVEDELETE(h,k,l) \
109 	  save_delete(SOFT_CAST(HV*)(h), SOFT_CAST(char*)(k), (I32)(l))
110 #define SAVEDESTRUCTOR(f,p) \
111 	  save_destructor((DESTRUCTORFUNC_NOCONTEXT_t)(f), SOFT_CAST(void*)(p))
112 
113 #define SAVEDESTRUCTOR_X(f,p) \
114 	  save_destructor_x((DESTRUCTORFUNC_t)(f), SOFT_CAST(void*)(p))
115 
116 #define SAVESTACK_POS() \
117     STMT_START {				\
118 	SSCHECK(2);				\
119 	SSPUSHINT(PL_stack_sp - PL_stack_base);	\
120 	SSPUSHINT(SAVEt_STACK_POS);		\
121     } STMT_END
122 
123 #define SAVEOP()	save_op()
124 
125 #define SAVEHINTS() \
126     STMT_START {				\
127 	if (PL_hints & HINT_LOCALIZE_HH)	\
128 	    save_hints();			\
129 	else {					\
130 	    SSCHECK(2);				\
131 	    SSPUSHINT(PL_hints);		\
132 	    SSPUSHINT(SAVEt_HINTS);		\
133 	}					\
134     } STMT_END
135 
136 #define SAVECOMPPAD() \
137     STMT_START {						\
138 	if (PL_comppad && PL_curpad == AvARRAY(PL_comppad)) {	\
139 	    SSCHECK(2);						\
140 	    SSPUSHPTR((SV*)PL_comppad);				\
141 	    SSPUSHINT(SAVEt_COMPPAD);				\
142 	}							\
143 	else {							\
144 	    SAVEVPTR(PL_curpad);				\
145 	    SAVESPTR(PL_comppad);				\
146 	}							\
147     } STMT_END
148 
149 #ifdef USE_ITHREADS
150 #  define SAVECOPSTASH(cop)	SAVEPPTR(CopSTASHPV(cop))
151 #  define SAVECOPFILE(cop)	SAVEPPTR(CopFILE(cop))
152 #else
153 #  define SAVECOPSTASH(cop)	SAVESPTR(CopSTASH(cop))
154 #  define SAVECOPFILE(cop)	SAVESPTR(CopFILEGV(cop))
155 #endif
156 
157 #define SAVECOPLINE(cop)	SAVEI16(CopLINE(cop))
158 
159 /* SSNEW() temporarily allocates a specified number of bytes of data on the
160  * savestack.  It returns an integer index into the savestack, because a
161  * pointer would get broken if the savestack is moved on reallocation.
162  * SSNEWa() works like SSNEW(), but also aligns the data to the specified
163  * number of bytes.  MEM_ALIGNBYTES is perhaps the most useful.  The
164  * alignment will be preserved therough savestack reallocation *only* if
165  * realloc returns data aligned to a size divisible by `align'!
166  *
167  * SSPTR() converts the index returned by SSNEW/SSNEWa() into a pointer.
168  */
169 
170 #define SSNEW(size)             save_alloc(size, 0)
171 #define SSNEWa(size,align)	save_alloc(size, \
172     (align - ((int)((caddr_t)&PL_savestack[PL_savestack_ix]) % align)) % align)
173 
174 #define SSPTR(off,type)         ((type) ((char*)PL_savestack + off))
175 
176 /* A jmpenv packages the state required to perform a proper non-local jump.
177  * Note that there is a start_env initialized when perl starts, and top_env
178  * points to this initially, so top_env should always be non-null.
179  *
180  * Existence of a non-null top_env->je_prev implies it is valid to call
181  * longjmp() at that runlevel (we make sure start_env.je_prev is always
182  * null to ensure this).
183  *
184  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
185  * establish a local jmpenv to handle exception traps.  Care must be taken
186  * to restore the previous value of je_mustcatch before exiting the
187  * stack frame iff JMPENV_PUSH was not called in that stack frame.
188  * GSAR 97-03-27
189  */
190 
191 struct jmpenv {
192     struct jmpenv *	je_prev;
193     Sigjmp_buf		je_buf;		/* only for use if !je_throw */
194     int			je_ret;		/* last exception thrown */
195     bool		je_mustcatch;	/* need to call longjmp()? */
196 #ifdef PERL_FLEXIBLE_EXCEPTIONS
197     void		(*je_throw)(int v); /* last for bincompat */
198     bool		je_noset;	/* no need for setjmp() */
199 #endif
200 };
201 
202 typedef struct jmpenv JMPENV;
203 
204 #ifdef OP_IN_REGISTER
205 #define OP_REG_TO_MEM	PL_opsave = op
206 #define OP_MEM_TO_REG	op = PL_opsave
207 #else
208 #define OP_REG_TO_MEM	NOOP
209 #define OP_MEM_TO_REG	NOOP
210 #endif
211 
212 /*
213  * How to build the first jmpenv.
214  *
215  * top_env needs to be non-zero. It points to an area
216  * in which longjmp() stuff is stored, as C callstack
217  * info there at least is thread specific this has to
218  * be per-thread. Otherwise a 'die' in a thread gives
219  * that thread the C stack of last thread to do an eval {}!
220  */
221 
222 #define JMPENV_BOOTSTRAP \
223     STMT_START {				\
224 	Zero(&PL_start_env, 1, JMPENV);		\
225 	PL_start_env.je_ret = -1;		\
226 	PL_start_env.je_mustcatch = TRUE;	\
227 	PL_top_env = &PL_start_env;		\
228     } STMT_END
229 
230 #ifdef PERL_FLEXIBLE_EXCEPTIONS
231 
232 /*
233  * These exception-handling macros are split up to
234  * ease integration with C++ exceptions.
235  *
236  * To use C++ try+catch to catch Perl exceptions, an extension author
237  * needs to first write an extern "C" function to throw an appropriate
238  * exception object; typically it will be or contain an integer,
239  * because Perl's internals use integers to track exception types:
240  *    extern "C" { static void thrower(int i) { throw i; } }
241  *
242  * Then (as shown below) the author needs to use, not the simple
243  * JMPENV_PUSH, but several of its constitutent macros, to arrange for
244  * the Perl internals to call thrower() rather than longjmp() to
245  * report exceptions:
246  *
247  *    dJMPENV;
248  *    JMPENV_PUSH_INIT(thrower);
249  *    try {
250  *        ... stuff that may throw exceptions ...
251  *    }
252  *    catch (int why) {  // or whatever matches thrower()
253  *        JMPENV_POST_CATCH;
254  *        EXCEPT_SET(why);
255  *        switch (why) {
256  *          ... // handle various Perl exception codes
257  *        }
258  *    }
259  *    JMPENV_POP;  // don't forget this!
260  */
261 
262 /*
263  * Function that catches/throws, and its callback for the
264  *  body of protected processing.
265  */
266 typedef void *(CPERLscope(*protect_body_t)) (pTHX_ va_list);
267 typedef void *(CPERLscope(*protect_proc_t)) (pTHX_ volatile JMPENV *pcur_env,
268 					     int *, protect_body_t, ...);
269 
270 #define dJMPENV	JMPENV cur_env;	\
271 		volatile JMPENV *pcur_env = ((cur_env.je_noset = 0),&cur_env)
272 
273 #define JMPENV_PUSH_INIT_ENV(ce,THROWFUNC) \
274     STMT_START {					\
275 	(ce).je_throw = (THROWFUNC);			\
276 	(ce).je_ret = -1;				\
277 	(ce).je_mustcatch = FALSE;			\
278 	(ce).je_prev = PL_top_env;			\
279 	PL_top_env = &(ce);				\
280 	OP_REG_TO_MEM;					\
281     } STMT_END
282 
283 #define JMPENV_PUSH_INIT(THROWFUNC) JMPENV_PUSH_INIT_ENV(*(JMPENV*)pcur_env,THROWFUNC)
284 
285 #define JMPENV_POST_CATCH_ENV(ce) \
286     STMT_START {					\
287 	OP_MEM_TO_REG;					\
288 	PL_top_env = &(ce);				\
289     } STMT_END
290 
291 #define JMPENV_POST_CATCH JMPENV_POST_CATCH_ENV(*(JMPENV*)pcur_env)
292 
293 #define JMPENV_PUSH_ENV(ce,v) \
294     STMT_START {						\
295 	if (!(ce).je_noset) {					\
296 	    DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",	\
297 			     ce, PL_top_env));			\
298 	    JMPENV_PUSH_INIT_ENV(ce,NULL);			\
299 	    EXCEPT_SET_ENV(ce,PerlProc_setjmp((ce).je_buf, 1));\
300 	    (ce).je_noset = 1;					\
301 	}							\
302 	else							\
303 	    EXCEPT_SET_ENV(ce,0);				\
304 	JMPENV_POST_CATCH_ENV(ce);				\
305 	(v) = EXCEPT_GET_ENV(ce);				\
306     } STMT_END
307 
308 #define JMPENV_PUSH(v) JMPENV_PUSH_ENV(*(JMPENV*)pcur_env,v)
309 
310 #define JMPENV_POP_ENV(ce) \
311     STMT_START {						\
312 	if (PL_top_env == &(ce))				\
313 	    PL_top_env = (ce).je_prev;				\
314     } STMT_END
315 
316 #define JMPENV_POP  JMPENV_POP_ENV(*(JMPENV*)pcur_env)
317 
318 #define JMPENV_JUMP(v) \
319     STMT_START {						\
320 	OP_REG_TO_MEM;						\
321 	if (PL_top_env->je_prev) {				\
322 	    if (PL_top_env->je_throw)				\
323 		PL_top_env->je_throw(v);			\
324 	    else						\
325 		PerlProc_longjmp(PL_top_env->je_buf, (v));	\
326 	}							\
327 	if ((v) == 2)						\
328 	    PerlProc_exit(STATUS_NATIVE_EXPORT);		\
329 	PerlIO_printf(Perl_error_log, "panic: top_env\n");	\
330 	PerlProc_exit(1);					\
331     } STMT_END
332 
333 #define EXCEPT_GET_ENV(ce)	((ce).je_ret)
334 #define EXCEPT_GET		EXCEPT_GET_ENV(*(JMPENV*)pcur_env)
335 #define EXCEPT_SET_ENV(ce,v)	((ce).je_ret = (v))
336 #define EXCEPT_SET(v)		EXCEPT_SET_ENV(*(JMPENV*)pcur_env,v)
337 
338 #else /* !PERL_FLEXIBLE_EXCEPTIONS */
339 
340 #define dJMPENV		JMPENV cur_env
341 
342 #define JMPENV_PUSH(v) \
343     STMT_START {							\
344 	DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",	\
345 			 &cur_env, PL_top_env));			\
346 	cur_env.je_prev = PL_top_env;					\
347 	OP_REG_TO_MEM;							\
348 	cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, 1);		\
349 	OP_MEM_TO_REG;							\
350 	PL_top_env = &cur_env;						\
351 	cur_env.je_mustcatch = FALSE;					\
352 	(v) = cur_env.je_ret;						\
353     } STMT_END
354 
355 #define JMPENV_POP \
356     STMT_START { PL_top_env = cur_env.je_prev; } STMT_END
357 
358 #define JMPENV_JUMP(v) \
359     STMT_START {						\
360 	OP_REG_TO_MEM;						\
361 	if (PL_top_env->je_prev)				\
362 	    PerlProc_longjmp(PL_top_env->je_buf, (v));		\
363 	if ((v) == 2)						\
364 	    PerlProc_exit(STATUS_NATIVE_EXPORT);		\
365 	PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");	\
366 	PerlProc_exit(1);					\
367     } STMT_END
368 
369 #endif /* PERL_FLEXIBLE_EXCEPTIONS */
370 
371 #define CATCH_GET		(PL_top_env->je_mustcatch)
372 #define CATCH_SET(v)		(PL_top_env->je_mustcatch = (v))
373