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4ee9c684 | 1 | /* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. |
2 | Contributed by Andy Vaught | |
3 | ||
4 | This file is part of the GNU Fortran 95 runtime library (libgfortran). | |
5 | ||
6 | Libgfortran is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | Libgfortran is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with Libgfortran; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* Unix stream I/O module */ | |
22 | ||
23 | #include "config.h" | |
24 | #include <stdlib.h> | |
25 | #include <limits.h> | |
26 | ||
27 | #include <unistd.h> | |
28 | #include <sys/stat.h> | |
29 | #include <fcntl.h> | |
30 | ||
31 | #include <sys/mman.h> | |
32 | #include <string.h> | |
33 | #include <errno.h> | |
34 | ||
35 | #include "libgfortran.h" | |
36 | #include "io.h" | |
37 | ||
38 | #ifndef PATH_MAX | |
39 | #define PATH_MAX 1024 | |
40 | #endif | |
41 | ||
42 | #ifndef MAP_FAILED | |
43 | #define MAP_FAILED ((void *) -1) | |
44 | #endif | |
45 | ||
46 | /* This implementation of stream I/O is based on the paper: | |
47 | * | |
48 | * "Exploiting the advantages of mapped files for stream I/O", | |
49 | * O. Krieger, M. Stumm and R. Umrau, "Proceedings of the 1992 Winter | |
50 | * USENIX conference", p. 27-42. | |
51 | * | |
52 | * It differs in a number of ways from the version described in the | |
53 | * paper. First of all, threads are not an issue during I/O and we | |
54 | * also don't have to worry about having multiple regions, since | |
55 | * fortran's I/O model only allows you to be one place at a time. | |
56 | * | |
57 | * On the other hand, we have to be able to writing at the end of a | |
58 | * stream, read from the start of a stream or read and write blocks of | |
59 | * bytes from an arbitrary position. After opening a file, a pointer | |
60 | * to a stream structure is returned, which is used to handle file | |
61 | * accesses until the file is closed. | |
62 | * | |
63 | * salloc_at_r(stream, len, where)-- Given a stream pointer, return a | |
64 | * pointer to a block of memory that mirror the file at position | |
65 | * 'where' that is 'len' bytes long. The len integer is updated to | |
66 | * reflect how many bytes were actually read. The only reason for a | |
67 | * short read is end of file. The file pointer is updated. The | |
68 | * pointer is valid until the next call to salloc_*. | |
69 | * | |
70 | * salloc_at_w(stream, len, where)-- Given the stream pointer, returns | |
71 | * a pointer to a block of memory that is updated to reflect the state | |
72 | * of the file. The length of the buffer is always equal to that | |
73 | * requested. The buffer must be completely set by the caller. When | |
74 | * data has been written, the sfree() function must be called to | |
75 | * indicate that the caller is done writing data to the buffer. This | |
76 | * may or may not cause a physical write. | |
77 | * | |
78 | * Short forms of these are salloc_r() and salloc_w() which drop the | |
79 | * 'where' parameter and use the current file pointer. */ | |
80 | ||
81 | ||
82 | #define BUFFER_SIZE 8192 | |
83 | ||
84 | typedef struct | |
85 | { | |
86 | stream st; | |
87 | ||
88 | int fd; | |
89 | offset_t buffer_offset; /* File offset of the start of the buffer */ | |
90 | offset_t physical_offset; /* Current physical file offset */ | |
91 | offset_t logical_offset; /* Current logical file offset */ | |
92 | offset_t dirty_offset; /* Start of modified bytes in buffer */ | |
93 | offset_t file_length; /* Length of the file, -1 if not seekable. */ | |
94 | ||
95 | char *buffer; | |
96 | int len; /* Physical length of the current buffer */ | |
97 | int active; /* Length of valid bytes in the buffer */ | |
98 | ||
99 | int prot; | |
100 | int ndirty; /* Dirty bytes starting at dirty_offset */ | |
101 | ||
102 | unsigned unbuffered:1, mmaped:1; | |
103 | ||
104 | char small_buffer[BUFFER_SIZE]; | |
105 | ||
106 | } | |
107 | unix_stream; | |
108 | ||
109 | /*move_pos_offset()-- Move the record pointer right or left | |
110 | *relative to current position */ | |
111 | ||
112 | int | |
113 | move_pos_offset (stream* st, int pos_off) | |
114 | { | |
115 | unix_stream * str = (unix_stream*)st; | |
116 | if (pos_off < 0) | |
117 | { | |
118 | str->active += pos_off; | |
119 | if (str->active < 0) | |
120 | str->active = 0; | |
121 | ||
122 | str->logical_offset += pos_off; | |
123 | ||
124 | if (str->dirty_offset+str->ndirty > str->logical_offset) | |
125 | { | |
126 | if (str->ndirty + pos_off > 0) | |
127 | str->ndirty += pos_off ; | |
128 | else | |
129 | { | |
130 | str->dirty_offset += pos_off + pos_off; | |
131 | str->ndirty = 0 ; | |
132 | } | |
133 | } | |
134 | ||
135 | return pos_off ; | |
136 | } | |
137 | return 0 ; | |
138 | } | |
139 | ||
140 | ||
141 | /* fix_fd()-- Given a file descriptor, make sure it is not one of the | |
142 | * standard descriptors, returning a non-standard descriptor. If the | |
143 | * user specifies that system errors should go to standard output, | |
144 | * then closes standard output, we don't want the system errors to a | |
145 | * file that has been given file descriptor 1 or 0. We want to send | |
146 | * the error to the invalid descriptor. */ | |
147 | ||
148 | static int | |
149 | fix_fd (int fd) | |
150 | { | |
151 | int input, output, error; | |
152 | ||
153 | input = output = error = 0; | |
154 | ||
155 | /* Unix allocates the lowest descriptors first, so a loop is not | |
156 | * required, but this order is. */ | |
157 | ||
158 | if (fd == STDIN_FILENO) | |
159 | { | |
160 | fd = dup (fd); | |
161 | input = 1; | |
162 | } | |
163 | if (fd == STDOUT_FILENO) | |
164 | { | |
165 | fd = dup (fd); | |
166 | output = 1; | |
167 | } | |
168 | if (fd == STDERR_FILENO) | |
169 | { | |
170 | fd = dup (fd); | |
171 | error = 1; | |
172 | } | |
173 | ||
174 | if (input) | |
175 | close (STDIN_FILENO); | |
176 | if (output) | |
177 | close (STDOUT_FILENO); | |
178 | if (error) | |
179 | close (STDERR_FILENO); | |
180 | ||
181 | return fd; | |
182 | } | |
183 | ||
184 | ||
185 | /* write()-- Write a buffer to a descriptor, allowing for short writes */ | |
186 | ||
187 | static int | |
188 | writen (int fd, char *buffer, int len) | |
189 | { | |
190 | int n, n0; | |
191 | ||
192 | n0 = len; | |
193 | ||
194 | while (len > 0) | |
195 | { | |
196 | n = write (fd, buffer, len); | |
197 | if (n < 0) | |
198 | return n; | |
199 | ||
200 | buffer += n; | |
201 | len -= n; | |
202 | } | |
203 | ||
204 | return n0; | |
205 | } | |
206 | ||
207 | ||
208 | #if 0 | |
209 | /* readn()-- Read bytes into a buffer, allowing for short reads. If | |
210 | * fewer than len bytes are returned, it is because we've hit the end | |
211 | * of file. */ | |
212 | ||
213 | static int | |
214 | readn (int fd, char *buffer, int len) | |
215 | { | |
216 | int nread, n; | |
217 | ||
218 | nread = 0; | |
219 | ||
220 | while (len > 0) | |
221 | { | |
222 | n = read (fd, buffer, len); | |
223 | if (n < 0) | |
224 | return n; | |
225 | ||
226 | if (n == 0) | |
227 | return nread; | |
228 | ||
229 | buffer += n; | |
230 | nread += n; | |
231 | len -= n; | |
232 | } | |
233 | ||
234 | return nread; | |
235 | } | |
236 | #endif | |
237 | ||
238 | ||
239 | /* get_oserror()-- Get the most recent operating system error. For | |
240 | * unix, this is errno. */ | |
241 | ||
242 | const char * | |
243 | get_oserror (void) | |
244 | { | |
245 | ||
246 | return strerror (errno); | |
247 | } | |
248 | ||
249 | ||
250 | /* sys_exit()-- Terminate the program with an exit code */ | |
251 | ||
252 | void | |
253 | sys_exit (int code) | |
254 | { | |
255 | ||
256 | exit (code); | |
257 | } | |
258 | ||
259 | ||
260 | ||
261 | /********************************************************************* | |
262 | File descriptor stream functions | |
263 | *********************************************************************/ | |
264 | ||
265 | /* fd_flush()-- Write bytes that need to be written */ | |
266 | ||
267 | static try | |
268 | fd_flush (unix_stream * s) | |
269 | { | |
270 | ||
271 | if (s->ndirty == 0) | |
272 | return SUCCESS;; | |
273 | ||
274 | if (s->physical_offset != s->dirty_offset && | |
275 | lseek (s->fd, s->dirty_offset, SEEK_SET) < 0) | |
276 | return FAILURE; | |
277 | ||
278 | if (writen (s->fd, s->buffer + (s->dirty_offset - s->buffer_offset), | |
279 | s->ndirty) < 0) | |
280 | return FAILURE; | |
281 | ||
282 | s->physical_offset = s->dirty_offset + s->ndirty; | |
283 | if (s->physical_offset > s->file_length) | |
284 | s->file_length = s->physical_offset; | |
285 | s->ndirty = 0; | |
286 | ||
287 | return SUCCESS; | |
288 | } | |
289 | ||
290 | ||
291 | /* fd_alloc()-- Arrange a buffer such that the salloc() request can be | |
292 | * satisfied. This subroutine gets the buffer ready for whatever is | |
293 | * to come next. */ | |
294 | ||
295 | static void | |
296 | fd_alloc (unix_stream * s, offset_t where, int *len) | |
297 | { | |
298 | char *new_buffer; | |
299 | int n, read_len; | |
300 | ||
301 | if (*len <= BUFFER_SIZE) | |
302 | { | |
303 | new_buffer = s->small_buffer; | |
304 | read_len = BUFFER_SIZE; | |
305 | } | |
306 | else | |
307 | { | |
308 | new_buffer = get_mem (*len); | |
309 | read_len = *len; | |
310 | } | |
311 | ||
312 | /* Salvage bytes currently within the buffer. This is important for | |
313 | * devices that cannot seek. */ | |
314 | ||
315 | if (s->buffer != NULL && s->buffer_offset <= where && | |
316 | where <= s->buffer_offset + s->active) | |
317 | { | |
318 | ||
319 | n = s->active - (where - s->buffer_offset); | |
320 | memmove (new_buffer, s->buffer + (where - s->buffer_offset), n); | |
321 | ||
322 | s->active = n; | |
323 | } | |
324 | else | |
325 | { /* new buffer starts off empty */ | |
326 | s->active = 0; | |
327 | } | |
328 | ||
329 | s->buffer_offset = where; | |
330 | ||
331 | /* free the old buffer if necessary */ | |
332 | ||
333 | if (s->buffer != NULL && s->buffer != s->small_buffer) | |
334 | free_mem (s->buffer); | |
335 | ||
336 | s->buffer = new_buffer; | |
337 | s->len = read_len; | |
338 | s->mmaped = 0; | |
339 | } | |
340 | ||
341 | ||
342 | /* fd_alloc_r_at()-- Allocate a stream buffer for reading. Either | |
343 | * we've already buffered the data or we need to load it. Returns | |
344 | * NULL on I/O error. */ | |
345 | ||
346 | static char * | |
347 | fd_alloc_r_at (unix_stream * s, int *len, offset_t where) | |
348 | { | |
349 | offset_t m; | |
350 | int n; | |
351 | ||
352 | if (where == -1) | |
353 | where = s->logical_offset; | |
354 | ||
355 | if (s->buffer != NULL && s->buffer_offset <= where && | |
356 | where + *len <= s->buffer_offset + s->active) | |
357 | { | |
358 | ||
359 | /* Return a position within the current buffer */ | |
360 | ||
361 | s->logical_offset = where + *len; | |
362 | return s->buffer + where - s->buffer_offset; | |
363 | } | |
364 | ||
365 | fd_alloc (s, where, len); | |
366 | ||
367 | m = where + s->active; | |
368 | ||
369 | if (s->physical_offset != m && lseek (s->fd, m, SEEK_SET) < 0) | |
370 | return NULL; | |
371 | ||
372 | n = read (s->fd, s->buffer + s->active, s->len - s->active); | |
373 | if (n < 0) | |
374 | return NULL; | |
375 | ||
376 | s->physical_offset = where + n; | |
377 | ||
378 | s->active += n; | |
379 | if (s->active < *len) | |
380 | *len = s->active; /* Bytes actually available */ | |
381 | ||
382 | s->logical_offset = where + *len; | |
383 | ||
384 | return s->buffer; | |
385 | } | |
386 | ||
387 | ||
388 | /* fd_alloc_w_at()-- Allocate a stream buffer for writing. Either | |
389 | * we've already buffered the data or we need to load it. */ | |
390 | ||
391 | static char * | |
392 | fd_alloc_w_at (unix_stream * s, int *len, offset_t where) | |
393 | { | |
394 | offset_t n; | |
395 | ||
396 | if (where == -1) | |
397 | where = s->logical_offset; | |
398 | ||
399 | if (s->buffer == NULL || s->buffer_offset > where || | |
400 | where + *len > s->buffer_offset + s->len) | |
401 | { | |
402 | ||
403 | if (fd_flush (s) == FAILURE) | |
404 | return NULL; | |
405 | fd_alloc (s, where, len); | |
406 | } | |
407 | ||
408 | /* Return a position within the current buffer */ | |
409 | ||
410 | if (s->ndirty == 0) | |
411 | { /* First write into a clean buffer */ | |
412 | s->dirty_offset = where; | |
413 | s->ndirty = *len; | |
414 | } | |
415 | else | |
416 | { | |
417 | if (s->dirty_offset + s->ndirty == where) | |
418 | s->ndirty += *len; | |
419 | else | |
420 | fd_flush (s); /* Can't combine two dirty blocks */ | |
421 | } | |
422 | ||
423 | s->logical_offset = where + *len; | |
424 | ||
425 | n = s->logical_offset - s->buffer_offset; | |
426 | if (n > s->active) | |
427 | s->active = n; | |
428 | ||
429 | return s->buffer + where - s->buffer_offset; | |
430 | } | |
431 | ||
432 | ||
433 | static try | |
434 | fd_sfree (unix_stream * s) | |
435 | { | |
436 | ||
437 | if (s->ndirty != 0 && | |
438 | (s->buffer != s->small_buffer || options.all_unbuffered || | |
439 | s->unbuffered)) | |
440 | return fd_flush (s); | |
441 | ||
442 | return SUCCESS; | |
443 | } | |
444 | ||
445 | ||
446 | static int | |
447 | fd_seek (unix_stream * s, offset_t offset) | |
448 | { | |
449 | ||
450 | s->physical_offset = s->logical_offset = offset; | |
451 | ||
452 | return (lseek (s->fd, offset, SEEK_SET) < 0) ? FAILURE : SUCCESS; | |
453 | } | |
454 | ||
455 | ||
456 | /* truncate_file()-- Given a unit, truncate the file at the current | |
457 | * position. Sets the physical location to the new end of the file. | |
458 | * Returns nonzero on error. */ | |
459 | ||
460 | static try | |
461 | fd_truncate (unix_stream * s) | |
462 | { | |
463 | ||
464 | if (ftruncate (s->fd, s->logical_offset)) | |
465 | return FAILURE; | |
466 | ||
467 | s->physical_offset = s->file_length = s->logical_offset; | |
468 | ||
469 | if (lseek (s->fd, s->file_length, SEEK_SET) == -1) | |
470 | return FAILURE; | |
471 | ||
472 | return SUCCESS; | |
473 | } | |
474 | ||
475 | ||
476 | static try | |
477 | fd_close (unix_stream * s) | |
478 | { | |
479 | ||
480 | if (fd_flush (s) == FAILURE) | |
481 | return FAILURE; | |
482 | ||
483 | if (s->buffer != NULL && s->buffer != s->small_buffer) | |
484 | free_mem (s->buffer); | |
485 | ||
486 | if (close (s->fd) < 0) | |
487 | return FAILURE; | |
488 | ||
489 | free_mem (s); | |
490 | ||
491 | return SUCCESS; | |
492 | } | |
493 | ||
494 | ||
495 | static void | |
496 | fd_open (unix_stream * s) | |
497 | { | |
498 | ||
499 | if (isatty (s->fd)) | |
500 | s->unbuffered = 1; | |
501 | ||
502 | s->st.alloc_r_at = (void *) fd_alloc_r_at; | |
503 | s->st.alloc_w_at = (void *) fd_alloc_w_at; | |
504 | s->st.sfree = (void *) fd_sfree; | |
505 | s->st.close = (void *) fd_close; | |
506 | s->st.seek = (void *) fd_seek; | |
507 | s->st.truncate = (void *) fd_truncate; | |
508 | ||
509 | s->buffer = NULL; | |
510 | } | |
511 | ||
512 | ||
513 | /********************************************************************* | |
514 | mmap stream functions | |
515 | ||
516 | Because mmap() is not capable of extending a file, we have to keep | |
517 | track of how long the file is. We also have to be able to detect end | |
518 | of file conditions. If there are multiple writers to the file (which | |
519 | can only happen outside the current program), things will get | |
520 | confused. Then again, things will get confused anyway. | |
521 | ||
522 | *********************************************************************/ | |
523 | ||
524 | #if HAVE_MMAP | |
525 | ||
526 | static int page_size, page_mask; | |
527 | ||
528 | /* mmap_flush()-- Deletes a memory mapping if something is mapped. */ | |
529 | ||
530 | static try | |
531 | mmap_flush (unix_stream * s) | |
532 | { | |
533 | ||
534 | if (!s->mmaped) | |
535 | return fd_flush (s); | |
536 | ||
537 | if (s->buffer == NULL) | |
538 | return SUCCESS; | |
539 | ||
540 | if (munmap (s->buffer, s->active)) | |
541 | return FAILURE; | |
542 | ||
543 | s->buffer = NULL; | |
544 | s->active = 0; | |
545 | ||
546 | return SUCCESS; | |
547 | } | |
548 | ||
549 | ||
550 | /* mmap_alloc()-- mmap() a section of the file. The whole section is | |
551 | * guaranteed to be mappable. */ | |
552 | ||
553 | static try | |
554 | mmap_alloc (unix_stream * s, offset_t where, int *len) | |
555 | { | |
556 | offset_t offset; | |
557 | int length; | |
558 | char *p; | |
559 | ||
560 | if (mmap_flush (s) == FAILURE) | |
561 | return FAILURE; | |
562 | ||
563 | offset = where & page_mask; /* Round down to the next page */ | |
564 | ||
565 | length = ((where - offset) & page_mask) + 2 * page_size; | |
566 | ||
567 | p = mmap (NULL, length, s->prot, MAP_SHARED, s->fd, offset); | |
568 | if (p == (char *) MAP_FAILED) | |
569 | return FAILURE; | |
570 | ||
571 | s->mmaped = 1; | |
572 | s->buffer = p; | |
573 | s->buffer_offset = offset; | |
574 | s->active = length; | |
575 | ||
576 | return SUCCESS; | |
577 | } | |
578 | ||
579 | ||
580 | static char * | |
581 | mmap_alloc_r_at (unix_stream * s, int *len, offset_t where) | |
582 | { | |
583 | offset_t m; | |
584 | ||
585 | if (where == -1) | |
586 | where = s->logical_offset; | |
587 | ||
588 | m = where + *len; | |
589 | ||
590 | if ((s->buffer == NULL || s->buffer_offset > where || | |
591 | m > s->buffer_offset + s->active) && | |
592 | mmap_alloc (s, where, len) == FAILURE) | |
593 | return NULL; | |
594 | ||
595 | if (m > s->file_length) | |
596 | { | |
597 | *len = s->file_length - s->logical_offset; | |
598 | s->logical_offset = s->file_length; | |
599 | } | |
600 | else | |
601 | s->logical_offset = m; | |
602 | ||
603 | return s->buffer + (where - s->buffer_offset); | |
604 | } | |
605 | ||
606 | ||
607 | static char * | |
608 | mmap_alloc_w_at (unix_stream * s, int *len, offset_t where) | |
609 | { | |
610 | if (where == -1) | |
611 | where = s->logical_offset; | |
612 | ||
613 | /* If we're extending the file, we have to use file descriptor | |
614 | * methods. */ | |
615 | ||
616 | if (where + *len > s->file_length) | |
617 | { | |
618 | if (s->mmaped) | |
619 | mmap_flush (s); | |
620 | return fd_alloc_w_at (s, len, where); | |
621 | } | |
622 | ||
623 | if ((s->buffer == NULL || s->buffer_offset > where || | |
624 | where + *len > s->buffer_offset + s->active) && | |
625 | mmap_alloc (s, where, len) == FAILURE) | |
626 | return NULL; | |
627 | ||
628 | s->logical_offset = where + *len; | |
629 | ||
630 | return s->buffer + where - s->buffer_offset; | |
631 | } | |
632 | ||
633 | ||
634 | static int | |
635 | mmap_seek (unix_stream * s, offset_t offset) | |
636 | { | |
637 | ||
638 | s->logical_offset = offset; | |
639 | return SUCCESS; | |
640 | } | |
641 | ||
642 | ||
643 | static try | |
644 | mmap_close (unix_stream * s) | |
645 | { | |
646 | try t; | |
647 | ||
648 | t = mmap_flush (s); | |
649 | ||
650 | if (close (s->fd) < 0) | |
651 | t = FAILURE; | |
652 | free_mem (s); | |
653 | ||
654 | return t; | |
655 | } | |
656 | ||
657 | ||
658 | static try | |
659 | mmap_sfree (unix_stream * s) | |
660 | { | |
661 | ||
662 | return SUCCESS; | |
663 | } | |
664 | ||
665 | ||
666 | /* mmap_open()-- mmap_specific open. If the particular file cannot be | |
667 | * mmap()-ed, we fall back to the file descriptor functions. */ | |
668 | ||
669 | static try | |
670 | mmap_open (unix_stream * s) | |
671 | { | |
672 | char *p; | |
673 | int i; | |
674 | ||
675 | page_size = getpagesize (); | |
676 | page_mask = ~0; | |
677 | ||
678 | p = mmap (0, page_size, s->prot, MAP_SHARED, s->fd, 0); | |
679 | if (p == (char *) MAP_FAILED) | |
680 | { | |
681 | fd_open (s); | |
682 | return SUCCESS; | |
683 | } | |
684 | ||
685 | munmap (p, page_size); | |
686 | ||
687 | i = page_size >> 1; | |
688 | while (i != 0) | |
689 | { | |
690 | page_mask <<= 1; | |
691 | i >>= 1; | |
692 | } | |
693 | ||
694 | s->st.alloc_r_at = (void *) mmap_alloc_r_at; | |
695 | s->st.alloc_w_at = (void *) mmap_alloc_w_at; | |
696 | s->st.sfree = (void *) mmap_sfree; | |
697 | s->st.close = (void *) mmap_close; | |
698 | s->st.seek = (void *) mmap_seek; | |
699 | s->st.truncate = (void *) fd_truncate; | |
700 | ||
701 | if (lseek (s->fd, s->file_length, SEEK_SET) < 0) | |
702 | return FAILURE; | |
703 | ||
704 | return SUCCESS; | |
705 | } | |
706 | ||
707 | #endif | |
708 | ||
709 | ||
710 | /********************************************************************* | |
711 | memory stream functions - These are used for internal files | |
712 | ||
713 | The idea here is that a single stream structure is created and all | |
714 | requests must be satisfied from it. The location and size of the | |
715 | buffer is the character variable supplied to the READ or WRITE | |
716 | statement. | |
717 | ||
718 | *********************************************************************/ | |
719 | ||
720 | ||
721 | static char * | |
722 | mem_alloc_r_at (unix_stream * s, int *len, offset_t where) | |
723 | { | |
724 | offset_t n; | |
725 | ||
726 | if (where == -1) | |
727 | where = s->logical_offset; | |
728 | ||
729 | if (where < s->buffer_offset || where > s->buffer_offset + s->active) | |
730 | return NULL; | |
731 | ||
732 | if (is_internal_unit() && where + *len > s->file_length) | |
733 | return NULL; | |
734 | ||
735 | s->logical_offset = where + *len; | |
736 | ||
737 | n = (where - s->buffer_offset) - s->active; | |
738 | if (*len > n) | |
739 | *len = n; | |
740 | ||
741 | return s->buffer + (where - s->buffer_offset); | |
742 | } | |
743 | ||
744 | ||
745 | static char * | |
746 | mem_alloc_w_at (unix_stream * s, int *len, offset_t where) | |
747 | { | |
748 | offset_t m; | |
749 | ||
750 | if (where == -1) | |
751 | where = s->logical_offset; | |
752 | ||
753 | m = where + *len; | |
754 | ||
755 | if (where < s->buffer_offset || m > s->buffer_offset + s->active) | |
756 | return NULL; | |
757 | ||
758 | s->logical_offset = m; | |
759 | ||
760 | return s->buffer + (where - s->buffer_offset); | |
761 | } | |
762 | ||
763 | ||
764 | static int | |
765 | mem_seek (unix_stream * s, offset_t offset) | |
766 | { | |
767 | ||
768 | if (offset > s->file_length) | |
769 | { | |
770 | errno = ESPIPE; | |
771 | return FAILURE; | |
772 | } | |
773 | ||
774 | s->logical_offset = offset; | |
775 | return SUCCESS; | |
776 | } | |
777 | ||
778 | ||
779 | static int | |
780 | mem_truncate (unix_stream * s) | |
781 | { | |
782 | ||
783 | return SUCCESS; | |
784 | } | |
785 | ||
786 | ||
787 | static try | |
788 | mem_close (unix_stream * s) | |
789 | { | |
790 | ||
791 | return SUCCESS; | |
792 | } | |
793 | ||
794 | ||
795 | static try | |
796 | mem_sfree (unix_stream * s) | |
797 | { | |
798 | ||
799 | return SUCCESS; | |
800 | } | |
801 | ||
802 | ||
803 | ||
804 | /********************************************************************* | |
805 | Public functions -- A reimplementation of this module needs to | |
806 | define functional equivalents of the following. | |
807 | *********************************************************************/ | |
808 | ||
809 | /* empty_internal_buffer()-- Zero the buffer of Internal file */ | |
810 | ||
811 | void | |
812 | empty_internal_buffer(stream *strm) | |
813 | { | |
814 | unix_stream * s = (unix_stream *) strm; | |
815 | memset(s->buffer, ' ', s->file_length); | |
816 | } | |
817 | ||
818 | /* open_internal()-- Returns a stream structure from an internal file */ | |
819 | ||
820 | stream * | |
821 | open_internal (char *base, int length) | |
822 | { | |
823 | unix_stream *s; | |
824 | ||
825 | s = get_mem (sizeof (unix_stream)); | |
826 | ||
827 | s->buffer = base; | |
828 | s->buffer_offset = 0; | |
829 | ||
830 | s->logical_offset = 0; | |
831 | s->active = s->file_length = length; | |
832 | ||
833 | s->st.alloc_r_at = (void *) mem_alloc_r_at; | |
834 | s->st.alloc_w_at = (void *) mem_alloc_w_at; | |
835 | s->st.sfree = (void *) mem_sfree; | |
836 | s->st.close = (void *) mem_close; | |
837 | s->st.seek = (void *) mem_seek; | |
838 | s->st.truncate = (void *) mem_truncate; | |
839 | ||
840 | return (stream *) s; | |
841 | } | |
842 | ||
843 | ||
844 | /* fd_to_stream()-- Given an open file descriptor, build a stream | |
845 | * around it. */ | |
846 | ||
847 | static stream * | |
848 | fd_to_stream (int fd, int prot) | |
849 | { | |
850 | struct stat statbuf; | |
851 | unix_stream *s; | |
852 | ||
853 | s = get_mem (sizeof (unix_stream)); | |
854 | ||
855 | s->fd = fd; | |
856 | s->buffer_offset = 0; | |
857 | s->physical_offset = 0; | |
858 | s->logical_offset = 0; | |
859 | s->prot = prot; | |
860 | ||
861 | /* Get the current length of the file. */ | |
862 | ||
863 | fstat (fd, &statbuf); | |
864 | s->file_length = S_ISREG (statbuf.st_mode) ? statbuf.st_size : -1; | |
865 | ||
866 | #if HAVE_MMAP | |
867 | mmap_open (s); | |
868 | #else | |
869 | fd_open (s); | |
870 | #endif | |
871 | ||
872 | return (stream *) s; | |
873 | } | |
874 | ||
875 | ||
876 | /* unpack_filename()-- Given a fortran string and a pointer to a | |
877 | * buffer that is PATH_MAX characters, convert the fortran string to a | |
878 | * C string in the buffer. Returns nonzero if this is not possible. */ | |
879 | ||
880 | static int | |
881 | unpack_filename (char *cstring, const char *fstring, int len) | |
882 | { | |
883 | ||
884 | len = fstrlen (fstring, len); | |
885 | if (len >= PATH_MAX) | |
886 | return 1; | |
887 | ||
888 | memmove (cstring, fstring, len); | |
889 | cstring[len] = '\0'; | |
890 | ||
891 | return 0; | |
892 | } | |
893 | ||
894 | ||
895 | /* tempfile()-- Generate a temporary filename for a scratch file and | |
896 | * open it. mkstemp() opens the file for reading and writing, but the | |
897 | * library mode prevents anything that is not allowed. The descriptor | |
898 | * is returns, which is less than zero on error. The template is | |
899 | * pointed to by ioparm.file, which is copied into the unit structure | |
900 | * and freed later. */ | |
901 | ||
902 | static int | |
903 | tempfile (void) | |
904 | { | |
905 | const char *tempdir; | |
906 | char *template; | |
907 | int fd; | |
908 | ||
909 | tempdir = getenv ("GFORTRAN_TMPDIR"); | |
910 | if (tempdir == NULL) | |
911 | tempdir = getenv ("TMP"); | |
912 | if (tempdir == NULL) | |
913 | tempdir = DEFAULT_TEMPDIR; | |
914 | ||
915 | template = get_mem (strlen (tempdir) + 20); | |
916 | ||
917 | st_sprintf (template, "%s/gfortantmpXXXXXX", tempdir); | |
918 | ||
919 | fd = mkstemp (template); | |
920 | ||
921 | if (fd < 0) | |
922 | free_mem (template); | |
923 | else | |
924 | { | |
925 | ioparm.file = template; | |
926 | ioparm.file_len = strlen (template); /* Don't include trailing nul */ | |
927 | } | |
928 | ||
929 | return fd; | |
930 | } | |
931 | ||
932 | ||
933 | /* regular_file()-- Open a regular file. Returns the descriptor, which is less than zero on error. */ | |
934 | ||
935 | static int | |
936 | regular_file (unit_action action, unit_status status) | |
937 | { | |
938 | char path[PATH_MAX + 1]; | |
939 | struct stat statbuf; | |
940 | int mode; | |
941 | ||
942 | if (unpack_filename (path, ioparm.file, ioparm.file_len)) | |
943 | { | |
944 | errno = ENOENT; /* Fake an OS error */ | |
945 | return -1; | |
946 | } | |
947 | ||
948 | mode = 0; | |
949 | ||
950 | switch (action) | |
951 | { | |
952 | case ACTION_READ: | |
953 | mode = O_RDONLY; | |
954 | break; | |
955 | ||
956 | case ACTION_WRITE: | |
957 | mode = O_WRONLY; | |
958 | break; | |
959 | ||
960 | case ACTION_READWRITE: | |
961 | mode = O_RDWR; | |
962 | break; | |
963 | ||
964 | default: | |
965 | internal_error ("regular_file(): Bad action"); | |
966 | } | |
967 | ||
968 | switch (status) | |
969 | { | |
970 | case STATUS_NEW: | |
971 | mode |= O_CREAT | O_EXCL; | |
972 | break; | |
973 | ||
974 | case STATUS_OLD: /* file must exist, so check for its existence */ | |
975 | if (stat (path, &statbuf) < 0) | |
976 | return -1; | |
977 | break; | |
978 | ||
979 | case STATUS_UNKNOWN: | |
980 | case STATUS_SCRATCH: | |
981 | mode |= O_CREAT; | |
982 | break; | |
983 | ||
984 | case STATUS_REPLACE: | |
985 | mode |= O_TRUNC; | |
986 | break; | |
987 | ||
988 | default: | |
989 | internal_error ("regular_file(): Bad status"); | |
990 | } | |
991 | ||
992 | // mode |= O_LARGEFILE; | |
993 | ||
994 | return open (path, mode, | |
995 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); | |
996 | } | |
997 | ||
998 | ||
999 | /* open_external()-- Open an external file, unix specific version. | |
1000 | * Returns NULL on operating system error. */ | |
1001 | ||
1002 | stream * | |
1003 | open_external (unit_action action, unit_status status) | |
1004 | { | |
1005 | int fd, prot; | |
1006 | ||
1007 | fd = | |
1008 | (status == STATUS_SCRATCH) ? tempfile () : regular_file (action, status); | |
1009 | ||
1010 | if (fd < 0) | |
1011 | return NULL; | |
1012 | fd = fix_fd (fd); | |
1013 | ||
1014 | switch (action) | |
1015 | { | |
1016 | case ACTION_READ: | |
1017 | prot = PROT_READ; | |
1018 | break; | |
1019 | ||
1020 | case ACTION_WRITE: | |
1021 | prot = PROT_WRITE; | |
1022 | break; | |
1023 | ||
1024 | case ACTION_READWRITE: | |
1025 | prot = PROT_READ | PROT_WRITE; | |
1026 | break; | |
1027 | ||
1028 | default: | |
1029 | internal_error ("open_external(): Bad action"); | |
1030 | } | |
1031 | ||
1032 | /* If this is a scratch file, we can unlink it now and the file will | |
1033 | * go away when it is closed. */ | |
1034 | ||
1035 | if (status == STATUS_SCRATCH) | |
1036 | unlink (ioparm.file); | |
1037 | ||
1038 | return fd_to_stream (fd, prot); | |
1039 | } | |
1040 | ||
1041 | ||
1042 | /* input_stream()-- Return a stream pointer to the default input stream. | |
1043 | * Called on initialization. */ | |
1044 | ||
1045 | stream * | |
1046 | input_stream (void) | |
1047 | { | |
1048 | ||
1049 | return fd_to_stream (STDIN_FILENO, PROT_READ); | |
1050 | } | |
1051 | ||
1052 | ||
1053 | /* output_stream()-- Return a stream pointer to the default input stream. | |
1054 | * Called on initialization. */ | |
1055 | ||
1056 | stream * | |
1057 | output_stream (void) | |
1058 | { | |
1059 | ||
1060 | return fd_to_stream (STDOUT_FILENO, PROT_WRITE); | |
1061 | } | |
1062 | ||
1063 | ||
1064 | /* init_error_stream()-- Return a pointer to the error stream. This | |
1065 | * subroutine is called when the stream is needed, rather than at | |
1066 | * initialization. We want to work even if memory has been seriously | |
1067 | * corrupted. */ | |
1068 | ||
1069 | stream * | |
1070 | init_error_stream (void) | |
1071 | { | |
1072 | static unix_stream error; | |
1073 | ||
1074 | memset (&error, '\0', sizeof (error)); | |
1075 | ||
1076 | error.fd = options.use_stderr ? STDERR_FILENO : STDOUT_FILENO; | |
1077 | ||
1078 | error.st.alloc_w_at = (void *) fd_alloc_w_at; | |
1079 | error.st.sfree = (void *) fd_sfree; | |
1080 | ||
1081 | error.unbuffered = 1; | |
1082 | error.buffer = error.small_buffer; | |
1083 | ||
1084 | return (stream *) & error; | |
1085 | } | |
1086 | ||
1087 | ||
1088 | /* compare_file_filename()-- Given an open stream and a fortran string | |
1089 | * that is a filename, figure out if the file is the same as the | |
1090 | * filename. */ | |
1091 | ||
1092 | int | |
1093 | compare_file_filename (stream * s, const char *name, int len) | |
1094 | { | |
1095 | char path[PATH_MAX + 1]; | |
1096 | struct stat st1, st2; | |
1097 | ||
1098 | if (unpack_filename (path, name, len)) | |
1099 | return 0; /* Can't be the same */ | |
1100 | ||
1101 | /* If the filename doesn't exist, then there is no match with the | |
1102 | * existing file. */ | |
1103 | ||
1104 | if (stat (path, &st1) < 0) | |
1105 | return 0; | |
1106 | ||
1107 | fstat (((unix_stream *) s)->fd, &st2); | |
1108 | ||
1109 | return (st1.st_dev == st2.st_dev) && (st1.st_ino == st2.st_ino); | |
1110 | } | |
1111 | ||
1112 | ||
1113 | /* find_file0()-- Recursive work function for find_file() */ | |
1114 | ||
1115 | static unit_t * | |
1116 | find_file0 (unit_t * u, struct stat *st1) | |
1117 | { | |
1118 | struct stat st2; | |
1119 | unit_t *v; | |
1120 | ||
1121 | if (u == NULL) | |
1122 | return NULL; | |
1123 | ||
1124 | if (fstat (((unix_stream *) u->s)->fd, &st2) >= 0 && | |
1125 | st1->st_dev == st2.st_dev && st1->st_ino == st2.st_ino) | |
1126 | return u; | |
1127 | ||
1128 | v = find_file0 (u->left, st1); | |
1129 | if (v != NULL) | |
1130 | return v; | |
1131 | ||
1132 | v = find_file0 (u->right, st1); | |
1133 | if (v != NULL) | |
1134 | return v; | |
1135 | ||
1136 | return NULL; | |
1137 | } | |
1138 | ||
1139 | ||
1140 | /* find_file()-- Take the current filename and see if there is a unit | |
1141 | * that has the file already open. Returns a pointer to the unit if so. */ | |
1142 | ||
1143 | unit_t * | |
1144 | find_file (void) | |
1145 | { | |
1146 | char path[PATH_MAX + 1]; | |
1147 | struct stat statbuf; | |
1148 | ||
1149 | if (unpack_filename (path, ioparm.file, ioparm.file_len)) | |
1150 | return NULL; | |
1151 | ||
1152 | if (stat (path, &statbuf) < 0) | |
1153 | return NULL; | |
1154 | ||
1155 | return find_file0 (g.unit_root, &statbuf); | |
1156 | } | |
1157 | ||
1158 | ||
1159 | /* stream_at_bof()-- Returns nonzero if the stream is at the beginning | |
1160 | * of the file. */ | |
1161 | ||
1162 | int | |
1163 | stream_at_bof (stream * s) | |
1164 | { | |
1165 | unix_stream *us; | |
1166 | ||
1167 | us = (unix_stream *) s; | |
1168 | ||
1169 | if (!us->mmaped) | |
1170 | return 0; /* File is not seekable */ | |
1171 | ||
1172 | return us->logical_offset == 0; | |
1173 | } | |
1174 | ||
1175 | ||
1176 | /* stream_at_eof()-- Returns nonzero if the stream is at the beginning | |
1177 | * of the file. */ | |
1178 | ||
1179 | int | |
1180 | stream_at_eof (stream * s) | |
1181 | { | |
1182 | unix_stream *us; | |
1183 | ||
1184 | us = (unix_stream *) s; | |
1185 | ||
1186 | if (!us->mmaped) | |
1187 | return 0; /* File is not seekable */ | |
1188 | ||
1189 | return us->logical_offset == us->dirty_offset; | |
1190 | } | |
1191 | ||
1192 | ||
1193 | /* delete_file()-- Given a unit structure, delete the file associated | |
1194 | * with the unit. Returns nonzero if something went wrong. */ | |
1195 | ||
1196 | int | |
1197 | delete_file (unit_t * u) | |
1198 | { | |
1199 | char path[PATH_MAX + 1]; | |
1200 | ||
1201 | if (unpack_filename (path, u->file, u->file_len)) | |
1202 | { /* Shouldn't be possible */ | |
1203 | errno = ENOENT; | |
1204 | return 1; | |
1205 | } | |
1206 | ||
1207 | return unlink (path); | |
1208 | } | |
1209 | ||
1210 | ||
1211 | /* file_exists()-- Returns nonzero if the current filename exists on | |
1212 | * the system */ | |
1213 | ||
1214 | int | |
1215 | file_exists (void) | |
1216 | { | |
1217 | char path[PATH_MAX + 1]; | |
1218 | struct stat statbuf; | |
1219 | ||
1220 | if (unpack_filename (path, ioparm.file, ioparm.file_len)) | |
1221 | return 0; | |
1222 | ||
1223 | if (stat (path, &statbuf) < 0) | |
1224 | return 0; | |
1225 | ||
1226 | return 1; | |
1227 | } | |
1228 | ||
1229 | ||
1230 | ||
1231 | static const char *yes = "YES", *no = "NO", *unknown = "UNKNOWN"; | |
1232 | ||
1233 | /* inquire_sequential()-- Given a fortran string, determine if the | |
1234 | * file is suitable for sequential access. Returns a C-style | |
1235 | * string. */ | |
1236 | ||
1237 | const char * | |
1238 | inquire_sequential (const char *string, int len) | |
1239 | { | |
1240 | char path[PATH_MAX + 1]; | |
1241 | struct stat statbuf; | |
1242 | ||
1243 | if (string == NULL || | |
1244 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1245 | return unknown; | |
1246 | ||
1247 | if (S_ISREG (statbuf.st_mode) || | |
1248 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
1249 | return yes; | |
1250 | ||
1251 | if (S_ISDIR (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
1252 | return no; | |
1253 | ||
1254 | return unknown; | |
1255 | } | |
1256 | ||
1257 | ||
1258 | /* inquire_direct()-- Given a fortran string, determine if the file is | |
1259 | * suitable for direct access. Returns a C-style string. */ | |
1260 | ||
1261 | const char * | |
1262 | inquire_direct (const char *string, int len) | |
1263 | { | |
1264 | char path[PATH_MAX + 1]; | |
1265 | struct stat statbuf; | |
1266 | ||
1267 | if (string == NULL || | |
1268 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1269 | return unknown; | |
1270 | ||
1271 | if (S_ISREG (statbuf.st_mode) || S_ISBLK (statbuf.st_mode)) | |
1272 | return yes; | |
1273 | ||
1274 | if (S_ISDIR (statbuf.st_mode) || | |
1275 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
1276 | return no; | |
1277 | ||
1278 | return unknown; | |
1279 | } | |
1280 | ||
1281 | ||
1282 | /* inquire_formatted()-- Given a fortran string, determine if the file | |
1283 | * is suitable for formatted form. Returns a C-style string. */ | |
1284 | ||
1285 | const char * | |
1286 | inquire_formatted (const char *string, int len) | |
1287 | { | |
1288 | char path[PATH_MAX + 1]; | |
1289 | struct stat statbuf; | |
1290 | ||
1291 | if (string == NULL || | |
1292 | unpack_filename (path, string, len) || stat (path, &statbuf) < 0) | |
1293 | return unknown; | |
1294 | ||
1295 | if (S_ISREG (statbuf.st_mode) || | |
1296 | S_ISBLK (statbuf.st_mode) || | |
1297 | S_ISCHR (statbuf.st_mode) || S_ISFIFO (statbuf.st_mode)) | |
1298 | return yes; | |
1299 | ||
1300 | if (S_ISDIR (statbuf.st_mode)) | |
1301 | return no; | |
1302 | ||
1303 | return unknown; | |
1304 | } | |
1305 | ||
1306 | ||
1307 | /* inquire_unformatted()-- Given a fortran string, determine if the file | |
1308 | * is suitable for unformatted form. Returns a C-style string. */ | |
1309 | ||
1310 | const char * | |
1311 | inquire_unformatted (const char *string, int len) | |
1312 | { | |
1313 | ||
1314 | return inquire_formatted (string, len); | |
1315 | } | |
1316 | ||
1317 | ||
1318 | /* inquire_access()-- Given a fortran string, determine if the file is | |
1319 | * suitable for access. */ | |
1320 | ||
1321 | static const char * | |
1322 | inquire_access (const char *string, int len, int mode) | |
1323 | { | |
1324 | char path[PATH_MAX + 1]; | |
1325 | ||
1326 | if (string == NULL || unpack_filename (path, string, len) || | |
1327 | access (path, mode) < 0) | |
1328 | return no; | |
1329 | ||
1330 | return yes; | |
1331 | } | |
1332 | ||
1333 | ||
1334 | /* inquire_read()-- Given a fortran string, determine if the file is | |
1335 | * suitable for READ access. */ | |
1336 | ||
1337 | const char * | |
1338 | inquire_read (const char *string, int len) | |
1339 | { | |
1340 | ||
1341 | return inquire_access (string, len, R_OK); | |
1342 | } | |
1343 | ||
1344 | ||
1345 | /* inquire_write()-- Given a fortran string, determine if the file is | |
1346 | * suitable for READ access. */ | |
1347 | ||
1348 | const char * | |
1349 | inquire_write (const char *string, int len) | |
1350 | { | |
1351 | ||
1352 | return inquire_access (string, len, W_OK); | |
1353 | } | |
1354 | ||
1355 | ||
1356 | /* inquire_readwrite()-- Given a fortran string, determine if the file is | |
1357 | * suitable for read and write access. */ | |
1358 | ||
1359 | const char * | |
1360 | inquire_readwrite (const char *string, int len) | |
1361 | { | |
1362 | ||
1363 | return inquire_access (string, len, R_OK | W_OK); | |
1364 | } | |
1365 | ||
1366 | ||
1367 | /* file_length()-- Return the file length in bytes, -1 if unknown */ | |
1368 | ||
1369 | offset_t | |
1370 | file_length (stream * s) | |
1371 | { | |
1372 | ||
1373 | return ((unix_stream *) s)->file_length; | |
1374 | } | |
1375 | ||
1376 | ||
1377 | /* file_position()-- Return the current position of the file */ | |
1378 | ||
1379 | offset_t | |
1380 | file_position (stream * s) | |
1381 | { | |
1382 | ||
1383 | return ((unix_stream *) s)->logical_offset; | |
1384 | } | |
1385 | ||
1386 | ||
1387 | /* is_seekable()-- Return nonzero if the stream is seekable, zero if | |
1388 | * it is not */ | |
1389 | ||
1390 | int | |
1391 | is_seekable (stream * s) | |
1392 | { | |
1393 | ||
1394 | return ((unix_stream *) s)->mmaped; | |
1395 | } | |
1396 | ||
1397 | ||
1398 | /* How files are stored: This is an operating-system specific issue, | |
1399 | and therefore belongs here. There are three cases to consider. | |
1400 | ||
1401 | Direct Access: | |
1402 | Records are written as block of bytes corresponding to the record | |
1403 | length of the file. This goes for both formatted and unformatted | |
1404 | records. Positioning is done explicitly for each data transfer, | |
1405 | so positioning is not much of an issue. | |
1406 | ||
1407 | Sequential Formatted: | |
1408 | Records are separated by newline characters. The newline character | |
1409 | is prohibited from appearing in a string. If it does, this will be | |
1410 | messed up on the next read. End of file is also the end of a record. | |
1411 | ||
1412 | Sequential Unformatted: | |
1413 | In this case, we are merely copying bytes to and from main storage, | |
1414 | yet we need to keep track of varying record lengths. We adopt | |
1415 | the solution used by f2c. Each record contains a pair of length | |
1416 | markers: | |
1417 | ||
1418 | Length of record n in bytes | |
1419 | Data of record n | |
1420 | Length of record n in bytes | |
1421 | ||
1422 | Length of record n+1 in bytes | |
1423 | Data of record n+1 | |
1424 | Length of record n+1 in bytes | |
1425 | ||
1426 | The length is stored at the end of a record to allow backspacing to the | |
1427 | previous record. Between data transfer statements, the file pointer | |
1428 | is left pointing to the first length of the current record. | |
1429 | ||
1430 | ENDFILE records are never explicitly stored. | |
1431 | ||
1432 | */ |