xref: /openbsd-src/gnu/usr.bin/perl/pad.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*    pad.h
2  *
3  *    Copyright (C) 2002, 2003, 2005, 2006, 2007, 2008,
4  *    2009, 2010, 2011 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * This file defines the types and macros associated with the API for
10  * manipulating scratchpads, which are used by perl to store lexical
11  * variables, op targets and constants.
12  */
13 
14 /*
15 =head1 Pad Data Structures
16 */
17 
18 
19 /* offsets within a pad */
20 
21 #if PTRSIZE == 4
22 typedef U32TYPE PADOFFSET;
23 #else
24 #   if PTRSIZE == 8
25 typedef U64TYPE PADOFFSET;
26 #   endif
27 #endif
28 #define NOT_IN_PAD ((PADOFFSET) -1)
29 
30 
31 struct padlist {
32     SSize_t	xpadl_max;	/* max index for which array has space */
33     PAD **	xpadl_alloc;	/* pointer to beginning of array of AVs */
34     PADNAMELIST*xpadl_outid;	/* Padnamelist of outer pad; used as ID */
35 };
36 
37 
38 /* a value that PL_cop_seqmax is guaranteed never to be,
39  * flagging that a lexical is being introduced, or has not yet left scope
40  */
41 #define PERL_PADSEQ_INTRO  U32_MAX
42 
43 
44 /* B.xs needs these for the benefit of B::Deparse */
45 /* Low range end is exclusive (valid from the cop seq after this one) */
46 /* High range end is inclusive (valid up to this cop seq) */
47 
48 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
49 #  define COP_SEQ_RANGE_LOW(sv)						\
50 	(({ const SV *const _sv_cop_seq_range_low = (const SV *) (sv);	\
51 	  assert(SvTYPE(_sv_cop_seq_range_low) == SVt_NV		\
52 		 || SvTYPE(_sv_cop_seq_range_low) >= SVt_PVNV);		\
53 	  assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVAV);		\
54 	  assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVHV);		\
55 	  assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVCV);		\
56 	  assert(SvTYPE(_sv_cop_seq_range_low) != SVt_PVFM);		\
57 	  assert(!isGV_with_GP(_sv_cop_seq_range_low));			\
58 	  ((XPVNV*) MUTABLE_PTR(SvANY(_sv_cop_seq_range_low)))->xnv_u.xpad_cop_seq.xlow; \
59 	 }))
60 #  define COP_SEQ_RANGE_HIGH(sv)					\
61 	(({ const SV *const _sv_cop_seq_range_high = (const SV *) (sv);	\
62 	  assert(SvTYPE(_sv_cop_seq_range_high) == SVt_NV 		\
63                  || SvTYPE(_sv_cop_seq_range_high) >= SVt_PVNV);	\
64 	  assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVAV);		\
65 	  assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVHV);		\
66 	  assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVCV);		\
67 	  assert(SvTYPE(_sv_cop_seq_range_high) != SVt_PVFM);		\
68 	  assert(!isGV_with_GP(_sv_cop_seq_range_high));		\
69 	  ((XPVNV*) MUTABLE_PTR(SvANY(_sv_cop_seq_range_high)))->xnv_u.xpad_cop_seq.xhigh; \
70 	 }))
71 #  define PARENT_PAD_INDEX(sv)						\
72 	(({ const SV *const _sv_parent_pad_index = (const SV *) (sv);	\
73 	  assert(SvTYPE(_sv_parent_pad_index) == SVt_NV			\
74 		 || SvTYPE(_sv_parent_pad_index) >= SVt_PVNV);		\
75 	  assert(SvTYPE(_sv_parent_pad_index) != SVt_PVAV);		\
76 	  assert(SvTYPE(_sv_parent_pad_index) != SVt_PVHV);		\
77 	  assert(SvTYPE(_sv_parent_pad_index) != SVt_PVCV);		\
78 	  assert(SvTYPE(_sv_parent_pad_index) != SVt_PVFM);		\
79 	  assert(!isGV_with_GP(_sv_parent_pad_index));			\
80 	  ((XPVNV*) MUTABLE_PTR(SvANY(_sv_parent_pad_index)))->xnv_u.xpad_cop_seq.xlow; \
81 	 }))
82 #  define PARENT_FAKELEX_FLAGS(sv)					\
83 	(({ const SV *const _sv_parent_fakelex_flags = (const SV *) (sv); \
84 	  assert(SvTYPE(_sv_parent_fakelex_flags) == SVt_NV  		\
85 		 || SvTYPE(_sv_parent_fakelex_flags) >= SVt_PVNV);	\
86 	  assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVAV);		\
87 	  assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVHV);		\
88 	  assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVCV);		\
89 	  assert(SvTYPE(_sv_parent_fakelex_flags) != SVt_PVFM);		\
90 	  assert(!isGV_with_GP(_sv_parent_fakelex_flags));		\
91 	  ((XPVNV*) MUTABLE_PTR(SvANY(_sv_parent_fakelex_flags)))->xnv_u.xpad_cop_seq.xhigh; \
92 	 }))
93 #else
94 #  define COP_SEQ_RANGE_LOW(sv)		\
95 	(0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xlow))
96 #  define COP_SEQ_RANGE_HIGH(sv)	\
97 	(0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xhigh))
98 
99 
100 #  define PARENT_PAD_INDEX(sv)		\
101 	(0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xlow))
102 #  define PARENT_FAKELEX_FLAGS(sv)	\
103 	(0 + (((XPVNV*) SvANY(sv))->xnv_u.xpad_cop_seq.xhigh))
104 #endif
105 
106 /* Flags set in the SvIVX field of FAKE namesvs */
107 
108 #define PAD_FAKELEX_ANON   1 /* the lex is declared in an ANON, or ... */
109 #define PAD_FAKELEX_MULTI  2 /* the lex can be instantiated multiple times */
110 
111 /* flags for the pad_new() function */
112 
113 #define padnew_CLONE	1	/* this pad is for a cloned CV */
114 #define padnew_SAVE	2	/* save old globals */
115 #define padnew_SAVESUB	4	/* also save extra stuff for start of sub */
116 
117 /* values for the pad_tidy() function */
118 
119 typedef enum {
120 	padtidy_SUB,		/* tidy up a pad for a sub, */
121 	padtidy_SUBCLONE,	/* a cloned sub, */
122 	padtidy_FORMAT		/* or a format */
123 } padtidy_type;
124 
125 /* flags for pad_add_name_pvn. */
126 
127 #define padadd_OUR		0x01	   /* our declaration. */
128 #define padadd_STATE		0x02	   /* state declaration. */
129 #define padadd_NO_DUP_CHECK	0x04	   /* skip warning on dups. */
130 #define padadd_STALEOK		0x08	   /* allow stale lexical in active
131 					    * sub, but only one level up */
132 #define padadd_UTF8_NAME	SVf_UTF8   /* name is UTF-8 encoded. */
133 
134 /* ASSERT_CURPAD_LEGAL and ASSERT_CURPAD_ACTIVE respectively determine
135  * whether PL_comppad and PL_curpad are consistent and whether they have
136  * active values */
137 
138 #ifndef PERL_MAD
139 #  define pad_peg(label)
140 #endif
141 
142 #ifdef DEBUGGING
143 #  define ASSERT_CURPAD_LEGAL(label) \
144     pad_peg(label); \
145     if (PL_comppad ? (AvARRAY(PL_comppad) != PL_curpad) : (PL_curpad != 0))  \
146 	Perl_croak(aTHX_ "panic: illegal pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
147 	    label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
148 
149 
150 #  define ASSERT_CURPAD_ACTIVE(label) \
151     pad_peg(label); \
152     if (!PL_comppad || (AvARRAY(PL_comppad) != PL_curpad))		  \
153 	Perl_croak(aTHX_ "panic: invalid pad in %s: 0x%" UVxf "[0x%" UVxf "]",\
154 	    label, PTR2UV(PL_comppad), PTR2UV(PL_curpad));
155 #else
156 #  define ASSERT_CURPAD_LEGAL(label)
157 #  define ASSERT_CURPAD_ACTIVE(label)
158 #endif
159 
160 
161 
162 /* Note: the following three macros are actually defined in scope.h, but
163  * they are documented here for completeness, since they directly or
164  * indirectly affect pads.
165 
166 =for apidoc m|void|SAVEPADSV	|PADOFFSET po
167 Save a pad slot (used to restore after an iteration)
168 
169 XXX DAPM it would make more sense to make the arg a PADOFFSET
170 =for apidoc m|void|SAVECLEARSV	|SV **svp
171 Clear the pointed to pad value on scope exit.  (i.e. the runtime action of
172 'my')
173 
174 =for apidoc m|void|SAVECOMPPAD
175 save PL_comppad and PL_curpad
176 
177 
178 =for apidoc Amx|PAD **|PadlistARRAY|PADLIST padlist
179 The C array of a padlist, containing the pads.  Only subscript it with
180 numbers >= 1, as the 0th entry is not guaranteed to remain usable.
181 
182 =for apidoc Amx|SSize_t|PadlistMAX|PADLIST padlist
183 The index of the last allocated space in the padlist.  Note that the last
184 pad may be in an earlier slot.  Any entries following it will be NULL in
185 that case.
186 
187 =for apidoc Amx|PADNAMELIST *|PadlistNAMES|PADLIST padlist
188 The names associated with pad entries.
189 
190 =for apidoc Amx|PADNAME **|PadlistNAMESARRAY|PADLIST padlist
191 The C array of pad names.
192 
193 =for apidoc Amx|SSize_t|PadlistNAMESMAX|PADLIST padlist
194 The index of the last pad name.
195 
196 =for apidoc Amx|U32|PadlistREFCNT|PADLIST padlist
197 The reference count of the padlist.  Currently this is always 1.
198 
199 =for apidoc Amx|PADNAME **|PadnamelistARRAY|PADNAMELIST pnl
200 The C array of pad names.
201 
202 =for apidoc Amx|SSize_t|PadnamelistMAX|PADNAMELIST pnl
203 The index of the last pad name.
204 
205 =for apidoc Amx|SV **|PadARRAY|PAD pad
206 The C array of pad entries.
207 
208 =for apidoc Amx|SSize_t|PadMAX|PAD pad
209 The index of the last pad entry.
210 
211 =for apidoc Amx|char *|PadnamePV|PADNAME pn
212 The name stored in the pad name struct.  This returns NULL for a target or
213 GV slot.
214 
215 =for apidoc Amx|STRLEN|PadnameLEN|PADNAME pn
216 The length of the name.
217 
218 =for apidoc Amx|bool|PadnameUTF8|PADNAME pn
219 Whether PadnamePV is in UTF8.
220 
221 =for apidoc Amx|SV *|PadnameSV|PADNAME pn
222 Returns the pad name as an SV.  This is currently just C<pn>.  It will
223 begin returning a new mortal SV if pad names ever stop being SVs.
224 
225 =for apidoc m|bool|PadnameIsOUR|PADNAME pn
226 Whether this is an "our" variable.
227 
228 =for apidoc m|HV *|PadnameOURSTASH
229 The stash in which this "our" variable was declared.
230 
231 =for apidoc m|bool|PadnameOUTER|PADNAME pn
232 Whether this entry belongs to an outer pad.
233 
234 =for apidoc m|bool|PadnameIsSTATE|PADNAME pn
235 Whether this is a "state" variable.
236 
237 =for apidoc m|HV *|PadnameTYPE|PADNAME pn
238 The stash associated with a typed lexical.  This returns the %Foo:: hash
239 for C<my Foo $bar>.
240 
241 
242 =for apidoc m|SV *|PAD_SETSV	|PADOFFSET po|SV* sv
243 Set the slot at offset C<po> in the current pad to C<sv>
244 
245 =for apidoc m|SV *|PAD_SV	|PADOFFSET po
246 Get the value at offset C<po> in the current pad
247 
248 =for apidoc m|SV *|PAD_SVl	|PADOFFSET po
249 Lightweight and lvalue version of C<PAD_SV>.
250 Get or set the value at offset C<po> in the current pad.
251 Unlike C<PAD_SV>, does not print diagnostics with -DX.
252 For internal use only.
253 
254 =for apidoc m|SV *|PAD_BASE_SV	|PADLIST padlist|PADOFFSET po
255 Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
256 
257 =for apidoc m|void|PAD_SET_CUR	|PADLIST padlist|I32 n
258 Set the current pad to be pad C<n> in the padlist, saving
259 the previous current pad.  NB currently this macro expands to a string too
260 long for some compilers, so it's best to replace it with
261 
262     SAVECOMPPAD();
263     PAD_SET_CUR_NOSAVE(padlist,n);
264 
265 
266 =for apidoc m|void|PAD_SET_CUR_NOSAVE	|PADLIST padlist|I32 n
267 like PAD_SET_CUR, but without the save
268 
269 =for apidoc m|void|PAD_SAVE_SETNULLPAD
270 Save the current pad then set it to null.
271 
272 =for apidoc m|void|PAD_SAVE_LOCAL|PAD *opad|PAD *npad
273 Save the current pad to the local variable opad, then make the
274 current pad equal to npad
275 
276 =for apidoc m|void|PAD_RESTORE_LOCAL|PAD *opad
277 Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()
278 
279 =cut
280 */
281 
282 #define PadlistARRAY(pl)	(pl)->xpadl_alloc
283 #define PadlistMAX(pl)		(pl)->xpadl_max
284 #define PadlistNAMES(pl)	(*PadlistARRAY(pl))
285 #define PadlistNAMESARRAY(pl)	PadnamelistARRAY(PadlistNAMES(pl))
286 #define PadlistNAMESMAX(pl)	PadnamelistMAX(PadlistNAMES(pl))
287 #define PadlistREFCNT(pl)	1	/* reserved for future use */
288 
289 #define PadnamelistARRAY(pnl)	AvARRAY(pnl)
290 #define PadnamelistMAX(pnl)	AvFILLp(pnl)
291 #define PadnamelistMAXNAMED(pnl) \
292 	((XPVAV*) SvANY(pnl))->xmg_u.xmg_hash_index
293 
294 #define PadARRAY(pad)		AvARRAY(pad)
295 #define PadMAX(pad)		AvFILLp(pad)
296 
297 #define PadnamePV(pn)		(SvPOKp(pn) ? SvPVX(pn) : NULL)
298 #define PadnameLEN(pn)		((pn) == &PL_sv_undef ? 0 : SvCUR(pn))
299 #define PadnameUTF8(pn)		!!SvUTF8(pn)
300 #define PadnameSV(pn)		pn
301 #define PadnameIsOUR(pn)	!!SvPAD_OUR(pn)
302 #define PadnameOURSTASH(pn)	SvOURSTASH(pn)
303 #define PadnameOUTER(pn)	!!SvFAKE(pn)
304 #define PadnameIsSTATE(pn)	!!SvPAD_STATE(pn)
305 #define PadnameTYPE(pn)		(SvPAD_TYPED(pn) ? SvSTASH(pn) : NULL)
306 
307 
308 #ifdef DEBUGGING
309 #  define PAD_SV(po)	   pad_sv(po)
310 #  define PAD_SETSV(po,sv) pad_setsv(po,sv)
311 #else
312 #  define PAD_SV(po)       (PL_curpad[po])
313 #  define PAD_SETSV(po,sv) PL_curpad[po] = (sv)
314 #endif
315 
316 #define PAD_SVl(po)       (PL_curpad[po])
317 
318 #define PAD_BASE_SV(padlist, po) \
319 	(PadlistARRAY(padlist)[1])					\
320 	    ? AvARRAY(MUTABLE_AV((PadlistARRAY(padlist)[1])))[po] \
321 	    : NULL;
322 
323 
324 #define PAD_SET_CUR_NOSAVE(padlist,nth) \
325 	PL_comppad = (PAD*) (PadlistARRAY(padlist)[nth]);	\
326 	PL_curpad = AvARRAY(PL_comppad);			\
327 	DEBUG_Xv(PerlIO_printf(Perl_debug_log,			\
328 	      "Pad 0x%" UVxf "[0x%" UVxf "] set_cur    depth=%d\n",	\
329 	      PTR2UV(PL_comppad), PTR2UV(PL_curpad), (int)(nth)));
330 
331 
332 #define PAD_SET_CUR(padlist,nth) \
333 	SAVECOMPPAD();						\
334 	PAD_SET_CUR_NOSAVE(padlist,nth);
335 
336 
337 #define PAD_SAVE_SETNULLPAD()	SAVECOMPPAD(); \
338 	PL_comppad = NULL; PL_curpad = NULL;	\
339 	DEBUG_Xv(PerlIO_printf(Perl_debug_log, "Pad set_null\n"));
340 
341 #define PAD_SAVE_LOCAL(opad,npad) \
342 	opad = PL_comppad;					\
343 	PL_comppad = (npad);					\
344 	PL_curpad =  PL_comppad ? AvARRAY(PL_comppad) : NULL;	\
345 	DEBUG_Xv(PerlIO_printf(Perl_debug_log,			\
346 	      "Pad 0x%" UVxf "[0x%" UVxf "] save_local\n",		\
347 	      PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
348 
349 #define PAD_RESTORE_LOCAL(opad) \
350         assert(!opad || !SvIS_FREED(opad));					\
351 	PL_comppad = opad;						\
352 	PL_curpad =  PL_comppad ? AvARRAY(PL_comppad) : NULL;	\
353 	DEBUG_Xv(PerlIO_printf(Perl_debug_log,			\
354 	      "Pad 0x%" UVxf "[0x%" UVxf "] restore_local\n",	\
355 	      PTR2UV(PL_comppad), PTR2UV(PL_curpad)));
356 
357 
358 /*
359 =for apidoc m|void|CX_CURPAD_SAVE|struct context
360 Save the current pad in the given context block structure.
361 
362 =for apidoc m|SV *|CX_CURPAD_SV|struct context|PADOFFSET po
363 Access the SV at offset po in the saved current pad in the given
364 context block structure (can be used as an lvalue).
365 
366 =cut
367 */
368 
369 #define CX_CURPAD_SAVE(block)  (block).oldcomppad = PL_comppad
370 #define CX_CURPAD_SV(block,po) (AvARRAY(MUTABLE_AV(((block).oldcomppad)))[po])
371 
372 
373 /*
374 =for apidoc m|U32|PAD_COMPNAME_FLAGS|PADOFFSET po
375 Return the flags for the current compiling pad name
376 at offset C<po>.  Assumes a valid slot entry.
377 
378 =for apidoc m|char *|PAD_COMPNAME_PV|PADOFFSET po
379 Return the name of the current compiling pad name
380 at offset C<po>.  Assumes a valid slot entry.
381 
382 =for apidoc m|HV *|PAD_COMPNAME_TYPE|PADOFFSET po
383 Return the type (stash) of the current compiling pad name at offset
384 C<po>.  Must be a valid name.  Returns null if not typed.
385 
386 =for apidoc m|HV *|PAD_COMPNAME_OURSTASH|PADOFFSET po
387 Return the stash associated with an C<our> variable.
388 Assumes the slot entry is a valid C<our> lexical.
389 
390 =for apidoc m|STRLEN|PAD_COMPNAME_GEN|PADOFFSET po
391 The generation number of the name at offset C<po> in the current
392 compiling pad (lvalue).  Note that C<SvUVX> is hijacked for this purpose.
393 
394 =for apidoc m|STRLEN|PAD_COMPNAME_GEN_set|PADOFFSET po|int gen
395 Sets the generation number of the name at offset C<po> in the current
396 ling pad (lvalue) to C<gen>.  Note that C<SvUV_set> is hijacked for this purpose.
397 
398 =cut
399 
400 */
401 
402 #define PAD_COMPNAME(po)	PAD_COMPNAME_SV(po)
403 #define PAD_COMPNAME_SV(po) (*av_fetch(PL_comppad_name, (po), FALSE))
404 #define PAD_COMPNAME_FLAGS(po) SvFLAGS(PAD_COMPNAME_SV(po))
405 #define PAD_COMPNAME_FLAGS_isOUR(po) SvPAD_OUR(PAD_COMPNAME_SV(po))
406 #define PAD_COMPNAME_PV(po) SvPV_nolen(PAD_COMPNAME_SV(po))
407 
408 #define PAD_COMPNAME_TYPE(po) pad_compname_type(po)
409 
410 #define PAD_COMPNAME_OURSTASH(po) \
411     (SvOURSTASH(PAD_COMPNAME_SV(po)))
412 
413 #define PAD_COMPNAME_GEN(po) ((STRLEN)SvUVX(AvARRAY(PL_comppad_name)[po]))
414 
415 #define PAD_COMPNAME_GEN_set(po, gen) SvUV_set(AvARRAY(PL_comppad_name)[po], (UV)(gen))
416 
417 
418 /*
419 =for apidoc m|void|PAD_CLONE_VARS|PerlInterpreter *proto_perl|CLONE_PARAMS* param
420 Clone the state variables associated with running and compiling pads.
421 
422 =cut
423 */
424 
425 /* NB - we set PL_comppad to null unless it points at a value that
426  * has already been dup'ed, ie it points to part of an active padlist.
427  * Otherwise PL_comppad ends up being a leaked scalar in code like
428  * the following:
429  *     threads->create(sub { threads->create(sub {...} ) } );
430  * where the second thread dups the outer sub's comppad but not the
431  * sub's CV or padlist. */
432 
433 #define PAD_CLONE_VARS(proto_perl, param)				\
434     PL_comppad			= av_dup(proto_perl->Icomppad, param);	\
435     PL_curpad = PL_comppad ?  AvARRAY(PL_comppad) : NULL;		\
436     PL_comppad_name		= av_dup(proto_perl->Icomppad_name, param); \
437     PL_comppad_name_fill	= proto_perl->Icomppad_name_fill;	\
438     PL_comppad_name_floor	= proto_perl->Icomppad_name_floor;	\
439     PL_min_intro_pending	= proto_perl->Imin_intro_pending;	\
440     PL_max_intro_pending	= proto_perl->Imax_intro_pending;	\
441     PL_padix			= proto_perl->Ipadix;			\
442     PL_padix_floor		= proto_perl->Ipadix_floor;		\
443     PL_pad_reset_pending	= proto_perl->Ipad_reset_pending;	\
444     PL_cop_seqmax		= proto_perl->Icop_seqmax;
445 
446 /*
447 =for apidoc Am|PADOFFSET|pad_add_name_pvs|const char *name|U32 flags|HV *typestash|HV *ourstash
448 
449 Exactly like L</pad_add_name_pvn>, but takes a literal string instead
450 of a string/length pair.
451 
452 =cut
453 */
454 
455 #define pad_add_name_pvs(name,flags,typestash,ourstash) \
456     Perl_pad_add_name_pvn(aTHX_ STR_WITH_LEN(name), flags, typestash, ourstash)
457 
458 /*
459 =for apidoc Am|PADOFFSET|pad_findmy_pvs|const char *name|U32 flags
460 
461 Exactly like L</pad_findmy_pvn>, but takes a literal string instead
462 of a string/length pair.
463 
464 =cut
465 */
466 
467 #define pad_findmy_pvs(name,flags) \
468     Perl_pad_findmy_pvn(aTHX_ STR_WITH_LEN(name), flags)
469 
470 /*
471  * Local variables:
472  * c-indentation-style: bsd
473  * c-basic-offset: 4
474  * indent-tabs-mode: nil
475  * End:
476  *
477  * ex: set ts=8 sts=4 sw=4 et:
478  */
479