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