GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/cvs/diff3.c Lines: 0 360 0.0 %
Date: 2017-11-13 Branches: 0 218 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: diff3.c,v 1.62 2016/10/18 21:06:52 millert Exp $	*/
2
3
/*
4
 * Copyright (C) Caldera International Inc.  2001-2002.
5
 * All rights reserved.
6
 *
7
 * Redistribution and use in source and binary forms, with or without
8
 * modification, are permitted provided that the following conditions
9
 * are met:
10
 * 1. Redistributions of source code and documentation must retain the above
11
 *    copyright notice, this list of conditions and the following disclaimer.
12
 * 2. Redistributions in binary form must reproduce the above copyright
13
 *    notice, this list of conditions and the following disclaimer in the
14
 *    documentation and/or other materials provided with the distribution.
15
 * 3. All advertising materials mentioning features or use of this software
16
 *    must display the following acknowledgement:
17
 *	This product includes software developed or owned by Caldera
18
 *	International, Inc.
19
 * 4. Neither the name of Caldera International, Inc. nor the names of other
20
 *    contributors may be used to endorse or promote products derived from
21
 *    this software without specific prior written permission.
22
 *
23
 * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
24
 * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
25
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27
 * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
28
 * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
30
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
32
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
33
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34
 * POSSIBILITY OF SUCH DAMAGE.
35
 */
36
/*-
37
 * Copyright (c) 1991, 1993
38
 *	The Regents of the University of California.  All rights reserved.
39
 *
40
 * Redistribution and use in source and binary forms, with or without
41
 * modification, are permitted provided that the following conditions
42
 * are met:
43
 * 1. Redistributions of source code must retain the above copyright
44
 *    notice, this list of conditions and the following disclaimer.
45
 * 2. Redistributions in binary form must reproduce the above copyright
46
 *    notice, this list of conditions and the following disclaimer in the
47
 *    documentation and/or other materials provided with the distribution.
48
 * 3. Neither the name of the University nor the names of its contributors
49
 *    may be used to endorse or promote products derived from this software
50
 *    without specific prior written permission.
51
 *
52
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62
 * SUCH DAMAGE.
63
 *
64
 *	@(#)diff3.c	8.1 (Berkeley) 6/6/93
65
 */
66
67
#include <ctype.h>
68
#include <errno.h>
69
#include <fcntl.h>
70
#include <stdio.h>
71
#include <stdlib.h>
72
#include <string.h>
73
#include <unistd.h>
74
75
#include "atomicio.h"
76
#include "cvs.h"
77
#include "diff.h"
78
79
/* diff3 - 3-way differential file comparison */
80
81
/* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
82
 *
83
 * d13 = diff report on f1 vs f3
84
 * d23 = diff report on f2 vs f3
85
 * f1, f2, f3 the 3 files
86
 * if changes in f1 overlap with changes in f3, m1 and m3 are used
87
 * to mark the overlaps; otherwise, the file names f1 and f3 are used
88
 * (only for options E and X).
89
 */
90
91
/*
92
 * "from" is first in range of changed lines; "to" is last+1
93
 * from=to=line after point of insertion for added lines.
94
 */
95
struct range {
96
	int from;
97
	int to;
98
};
99
100
struct diff {
101
	struct range old;
102
	struct range new;
103
};
104
105
static size_t szchanges;
106
107
static struct diff *d13;
108
static struct diff *d23;
109
110
/*
111
 * "de" is used to gather editing scripts.  These are later spewed out in
112
 * reverse order.  Its first element must be all zero, the "new" component
113
 * of "de" contains line positions or byte positions depending on when you
114
 * look (!?).  Array overlap indicates which sections in "de" correspond to
115
 * lines that are different in all three files.
116
 */
117
static struct diff *de;
118
static char *overlap;
119
static int overlapcnt = 0;
120
static FILE *fp[3];
121
static int cline[3];		/* # of the last-read line in each file (0-2) */
122
123
/*
124
 * the latest known correspondence between line numbers of the 3 files
125
 * is stored in last[1-3];
126
 */
127
static int last[4];
128
static int eflag;
129
static int oflag;		/* indicates whether to mark overlaps (-E or -X)*/
130
static int debug  = 0;
131
static char f1mark[PATH_MAX], f3mark[PATH_MAX];	/* markers for -E and -X */
132
133
static int duplicate(struct range *, struct range *);
134
static int edit(struct diff *, int, int);
135
static char *getchange(FILE *);
136
static char *get_line(FILE *, size_t *);
137
static int number(char **);
138
static size_t readin(int, struct diff **);
139
static int skip(int, int, char *);
140
static int edscript(int);
141
static int merge(size_t, size_t);
142
static void change(int, struct range *, int);
143
static void keep(int, struct range *);
144
static void prange(struct range *);
145
static void repos(int);
146
static void separate(const char *);
147
static void increase(void);
148
static int diff3_internal(int, char **, const char *, const char *);
149
150
int diff3_conflicts = 0;
151
RCSNUM *d3rev1 = NULL;
152
RCSNUM *d3rev2 = NULL;
153
154
static int fds[5];
155
156
void
157
cvs_merge_file(struct cvs_file *cf, int verbose)
158
{
159
	int i, argc;
160
	char *data, *patch;
161
	char *argv[5], r1[CVS_REV_BUFSZ], r2[CVS_REV_BUFSZ];
162
	char *dp13, *dp23, *path1, *path2, *path3;
163
	BUF *b1, *d1, *d2, *diffb;
164
	size_t dlen, plen;
165
	struct rcs_line *lp;
166
	struct rcs_lines *dlines, *plines;
167
168
	overlapcnt = 0;
169
	b1 = d1 = d2 = diffb = NULL;
170
171
	rcsnum_tostr(d3rev1, r1, sizeof(r1));
172
	rcsnum_tostr(d3rev2, r2, sizeof(r2));
173
174
	b1 = buf_load_fd(cf->fd);
175
	d1 = buf_alloc(128);
176
	d2 = buf_alloc(128);
177
	diffb = buf_alloc(128);
178
179
	(void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
180
	(void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
181
	(void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
182
183
	fds[2] = buf_write_stmp(b1, path1, NULL);
184
	if (verbose == 1)
185
		cvs_printf("Retrieving revision %s\n", r1);
186
	fds[3] = rcs_rev_write_stmp(cf->file_rcs, d3rev1, path2, 0);
187
	if (verbose == 1)
188
		cvs_printf("Retrieving revision %s\n", r2);
189
	fds[4] = rcs_rev_write_stmp(cf->file_rcs, d3rev2, path3, 0);
190
191
	diffreg(path1, path3, fds[2], fds[4], d1, D_FORCEASCII);
192
	diffreg(path2, path3, fds[3], fds[4], d2, D_FORCEASCII);
193
194
	(void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
195
	fds[0] = buf_write_stmp(d1, dp13, NULL);
196
	buf_free(d1);
197
198
	(void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
199
	fds[1] = buf_write_stmp(d2, dp23, NULL);
200
	buf_free(d2);
201
202
	argc = 0;
203
	diffbuf = diffb;
204
	argv[argc++] = dp13;
205
	argv[argc++] = dp23;
206
	argv[argc++] = path1;
207
	argv[argc++] = path2;
208
	argv[argc++] = path3;
209
210
	if (lseek(fds[2], 0, SEEK_SET) < 0)
211
		fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno));
212
	if (lseek(fds[3], 0, SEEK_SET) < 0)
213
		fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno));
214
	if (lseek(fds[4], 0, SEEK_SET) < 0)
215
		fatal("cvs_merge_file: lseek fds[4]: %s", strerror(errno));
216
217
	diff3_conflicts = diff3_internal(argc, argv, cf->file_path, r2);
218
	if (diff3_conflicts < 0)
219
		fatal("cvs_merge_file: merging failed for an unknown reason");
220
221
	plen = buf_len(diffb);
222
	patch = buf_release(diffb);
223
	dlen = buf_len(b1);
224
	data = buf_release(b1);
225
226
	if (verbose == 1)
227
		cvs_printf("Merging differences between %s and %s into `%s'\n",
228
		    r1, r2, cf->file_path);
229
230
	dlines = cvs_splitlines(data, dlen);
231
	plines = cvs_splitlines(patch, plen);
232
233
	ed_patch_lines(dlines, plines);
234
	cvs_freelines(plines);
235
236
	if (verbose == 1 && diff3_conflicts != 0) {
237
		cvs_log(LP_ERR, "%d conflict%s found during merge, "
238
		    "please correct.", diff3_conflicts,
239
		    (diff3_conflicts > 1) ? "s" : "");
240
	}
241
242
	(void)close(cf->fd);
243
	cf->fd = open(cf->file_path, O_CREAT | O_RDWR | O_TRUNC, 0644);
244
	if (cf->fd == -1) {
245
		fatal("cvs_merge_file: failed to reopen fd for writing: %s",
246
		    strerror(errno));
247
	}
248
249
	TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) {
250
		if (lp->l_line == NULL)
251
			continue;
252
253
		if (atomicio(vwrite, cf->fd, lp->l_line, lp->l_len) !=
254
		    lp->l_len)
255
			fatal("cvs_merge_file: %s", strerror(errno));
256
	}
257
258
	cvs_freelines(dlines);
259
260
	free(data);
261
	free(patch);
262
263
	for (i = 0; i < 3; i++)
264
		fclose(fp[i]);
265
266
	worklist_run(&temp_files, worklist_unlink);
267
268
	free(path1);
269
	free(path2);
270
	free(path3);
271
	free(dp13);
272
	free(dp23);
273
}
274
275
static int
276
diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
277
{
278
	size_t m, n;
279
	int i;
280
281
	eflag = 3;
282
	oflag = 1;
283
284
	if (argc < 5)
285
		return (-1);
286
287
	(void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
288
	(void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
289
290
	szchanges = 0;
291
	memset(last, 0, sizeof(last));
292
	memset(cline, 0, sizeof(cline));
293
	free(d13);
294
	free(d23);
295
	free(overlap);
296
	free(de);
297
298
	de = d13 = d23 = NULL;
299
	overlap = NULL;
300
301
	increase();
302
303
	/* fds[0] and fds[1] are closed in readin() */
304
	m = readin(fds[0], &d13);
305
	n = readin(fds[1], &d23);
306
307
	for (i = 0; i <= 2; i++) {
308
		if ((fp[i] = fdopen(fds[i + 2], "r")) == NULL) {
309
			cvs_log(LP_ERR, "%s", argv[i + 2]);
310
			return (-1);
311
		}
312
	}
313
314
	return (merge(m, n));
315
}
316
317
int
318
ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
319
{
320
	char op, *ep;
321
	struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after;
322
	int start, end, i, lineno;
323
	u_char tmp;
324
325
	dlp = TAILQ_FIRST(&(dlines->l_lines));
326
	lp = TAILQ_FIRST(&(plines->l_lines));
327
328
	end = 0;
329
	for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
330
	    lp = TAILQ_NEXT(lp, l_list)) {
331
		/* Skip blank lines */
332
		if (lp->l_len < 2)
333
			continue;
334
335
		/* NUL-terminate line buffer for strtol() safety. */
336
		tmp = lp->l_line[lp->l_len - 1];
337
		lp->l_line[lp->l_len - 1] = '\0';
338
339
		op = lp->l_line[strlen(lp->l_line) - 1];
340
		start = (int)strtol(lp->l_line, &ep, 10);
341
342
		/* Restore the last byte of the buffer */
343
		lp->l_line[lp->l_len - 1] = tmp;
344
345
		if (op == 'a') {
346
			if (start > dlines->l_nblines ||
347
			    start < 0 || *ep != 'a')
348
				fatal("ed_patch_lines %d", start);
349
		} else if (op == 'c') {
350
			if (start > dlines->l_nblines ||
351
			    start < 0 || (*ep != ',' && *ep != 'c'))
352
				fatal("ed_patch_lines");
353
354
			if (*ep == ',') {
355
				ep++;
356
				end = (int)strtol(ep, &ep, 10);
357
				if (end < 0 || *ep != 'c')
358
					fatal("ed_patch_lines");
359
			} else {
360
				end = start;
361
			}
362
		} else {
363
			fatal("invalid op %c found while merging", op);
364
		}
365
366
367
		for (;;) {
368
			if (dlp == NULL)
369
				break;
370
			if (dlp->l_lineno == start)
371
				break;
372
			if (dlp->l_lineno > start) {
373
				dlp = TAILQ_PREV(dlp, tqh, l_list);
374
			} else if (dlp->l_lineno < start) {
375
				ndlp = TAILQ_NEXT(dlp, l_list);
376
				if (ndlp->l_lineno > start)
377
					break;
378
				dlp = ndlp;
379
			}
380
		}
381
382
		if (dlp == NULL)
383
			fatal("ed_patch_lines");
384
385
386
		if (op == 'c') {
387
			insert_after = TAILQ_PREV(dlp, tqh, l_list);
388
			for (i = 0; i <= (end - start); i++) {
389
				ndlp = TAILQ_NEXT(dlp, l_list);
390
				TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
391
				dlp = ndlp;
392
			}
393
			dlp = insert_after;
394
		}
395
396
		if (op == 'a' || op == 'c') {
397
			for (;;) {
398
				ndlp = lp;
399
				lp = TAILQ_NEXT(lp, l_list);
400
				if (lp == NULL)
401
					fatal("ed_patch_lines");
402
403
				if (lp->l_len == 2 &&
404
				    lp->l_line[0] == '.' &&
405
				    lp->l_line[1] == '\n')
406
					break;
407
408
				TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
409
				TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
410
				    lp, l_list);
411
				dlp = lp;
412
413
				lp->l_lineno = start;
414
				lp = ndlp;
415
			}
416
		}
417
418
		/*
419
		 * always resort lines as the markers might be put at the
420
		 * same line as we first started editing.
421
		 */
422
		lineno = 0;
423
		TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
424
			sort->l_lineno = lineno++;
425
		dlines->l_nblines = lineno - 1;
426
	}
427
428
	return (0);
429
}
430
431
/*
432
 * Pick up the line numbers of all changes from one change file.
433
 * (This puts the numbers in a vector, which is not strictly necessary,
434
 * since the vector is processed in one sequential pass.
435
 * The vector could be optimized out of existence)
436
 */
437
static size_t
438
readin(int fd, struct diff **dd)
439
{
440
	int a, b, c, d;
441
	char kind, *p;
442
	size_t i;
443
444
	fp[0] = fdopen(fd, "r");
445
	if (fp[0] == NULL)
446
		fatal("readin: fdopen: %s", strerror(errno));
447
448
	for (i = 0; (p = getchange(fp[0])); i++) {
449
		if (i >= szchanges - 1)
450
			increase();
451
		a = b = number(&p);
452
		if (*p == ',') {
453
			p++;
454
			b = number(&p);
455
		}
456
		kind = *p++;
457
		c = d = number(&p);
458
		if (*p==',') {
459
			p++;
460
			d = number(&p);
461
		}
462
		if (kind == 'a')
463
			a++;
464
		if (kind == 'd')
465
			c++;
466
		b++;
467
		d++;
468
		(*dd)[i].old.from = a;
469
		(*dd)[i].old.to = b;
470
		(*dd)[i].new.from = c;
471
		(*dd)[i].new.to = d;
472
	}
473
474
	if (i) {
475
		(*dd)[i].old.from = (*dd)[i-1].old.to;
476
		(*dd)[i].new.from = (*dd)[i-1].new.to;
477
	}
478
479
	(void)fclose(fp[0]);
480
481
	return (i);
482
}
483
484
static int
485
number(char **lc)
486
{
487
	int nn;
488
489
	nn = 0;
490
	while (isdigit((unsigned char)(**lc)))
491
		nn = nn*10 + *(*lc)++ - '0';
492
493
	return (nn);
494
}
495
496
static char *
497
getchange(FILE *b)
498
{
499
	char *line;
500
501
	while ((line = get_line(b, NULL))) {
502
		if (isdigit((unsigned char)line[0]))
503
			return (line);
504
	}
505
506
	return (NULL);
507
}
508
509
static char *
510
get_line(FILE *b, size_t *n)
511
{
512
	char *cp;
513
	size_t len;
514
	static char *buf;
515
	static size_t bufsize;
516
517
	if ((cp = fgetln(b, &len)) == NULL)
518
		return (NULL);
519
520
	if (cp[len - 1] != '\n')
521
		len++;
522
	if (len + 1 > bufsize) {
523
		do {
524
			bufsize += 1024;
525
		} while (len + 1 > bufsize);
526
		buf = xreallocarray(buf, 1, bufsize);
527
	}
528
	memcpy(buf, cp, len - 1);
529
	buf[len - 1] = '\n';
530
	buf[len] = '\0';
531
	if (n != NULL)
532
		*n = len;
533
534
	return (buf);
535
}
536
537
static int
538
merge(size_t m1, size_t m2)
539
{
540
	struct diff *d1, *d2, *d3;
541
	int dpl, j, t1, t2;
542
543
	d1 = d13;
544
	d2 = d23;
545
	j = 0;
546
	for (;;) {
547
		t1 = (d1 < d13 + m1);
548
		t2 = (d2 < d23 + m2);
549
		if (!t1 && !t2)
550
			break;
551
552
		if (debug) {
553
			printf("%d,%d=%d,%d %d,%d=%d,%d\n",
554
			d1->old.from, d1->old.to,
555
			d1->new.from, d1->new.to,
556
			d2->old.from, d2->old.to,
557
			d2->new.from, d2->new.to);
558
		}
559
560
		/* first file is different from others */
561
		if (!t2 || (t1 && d1->new.to < d2->new.from)) {
562
			/* stuff peculiar to 1st file */
563
			if (eflag==0) {
564
				separate("1");
565
				change(1, &d1->old, 0);
566
				keep(2, &d1->new);
567
				change(3, &d1->new, 0);
568
			}
569
			d1++;
570
			continue;
571
		}
572
573
		/* second file is different from others */
574
		if (!t1 || (t2 && d2->new.to < d1->new.from)) {
575
			if (eflag==0) {
576
				separate("2");
577
				keep(1, &d2->new);
578
				change(2, &d2->old, 0);
579
				change(3, &d2->new, 0);
580
			}
581
			d2++;
582
			continue;
583
		}
584
585
		/*
586
		 * Merge overlapping changes in first file
587
		 * this happens after extension (see below).
588
		 */
589
		if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
590
			d1[1].old.from = d1->old.from;
591
			d1[1].new.from = d1->new.from;
592
			d1++;
593
			continue;
594
		}
595
596
		/* merge overlapping changes in second */
597
		if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
598
			d2[1].old.from = d2->old.from;
599
			d2[1].new.from = d2->new.from;
600
			d2++;
601
			continue;
602
		}
603
		/* stuff peculiar to third file or different in all */
604
		if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
605
			dpl = duplicate(&d1->old,&d2->old);
606
			if (dpl == -1)
607
				return (-1);
608
609
			/*
610
			 * dpl = 0 means all files differ
611
			 * dpl = 1 means files 1 and 2 identical
612
			 */
613
			if (eflag==0) {
614
				separate(dpl ? "3" : "");
615
				change(1, &d1->old, dpl);
616
				change(2, &d2->old, 0);
617
				d3 = d1->old.to > d1->old.from ? d1 : d2;
618
				change(3, &d3->new, 0);
619
			} else
620
				j = edit(d1, dpl, j);
621
			d1++;
622
			d2++;
623
			continue;
624
		}
625
626
		/*
627
		 * Overlapping changes from file 1 and 2; extend changes
628
		 * appropriately to make them coincide.
629
		 */
630
		if (d1->new.from < d2->new.from) {
631
			d2->old.from -= d2->new.from-d1->new.from;
632
			d2->new.from = d1->new.from;
633
		} else if (d2->new.from < d1->new.from) {
634
			d1->old.from -= d1->new.from-d2->new.from;
635
			d1->new.from = d2->new.from;
636
		}
637
		if (d1->new.to > d2->new.to) {
638
			d2->old.to += d1->new.to - d2->new.to;
639
			d2->new.to = d1->new.to;
640
		} else if (d2->new.to > d1->new.to) {
641
			d1->old.to += d2->new.to - d1->new.to;
642
			d1->new.to = d2->new.to;
643
		}
644
	}
645
646
	return (edscript(j));
647
}
648
649
static void
650
separate(const char *s)
651
{
652
	diff_output("====%s\n", s);
653
}
654
655
/*
656
 * The range of lines rold.from thru rold.to in file i is to be changed.
657
 * It is to be printed only if it does not duplicate something to be
658
 * printed later.
659
 */
660
static void
661
change(int i, struct range *rold, int fdup)
662
{
663
	diff_output("%d:", i);
664
	last[i] = rold->to;
665
	prange(rold);
666
	if (fdup || debug)
667
		return;
668
	i--;
669
	(void)skip(i, rold->from, NULL);
670
	(void)skip(i, rold->to, "  ");
671
}
672
673
/*
674
 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
675
 */
676
static void
677
prange(struct range *rold)
678
{
679
	if (rold->to <= rold->from)
680
		diff_output("%da\n", rold->from - 1);
681
	else {
682
		diff_output("%d", rold->from);
683
		if (rold->to > rold->from+1)
684
			diff_output(",%d", rold->to - 1);
685
		diff_output("c\n");
686
	}
687
}
688
689
/*
690
 * No difference was reported by diff between file 1 (or 2) and file 3,
691
 * and an artificial dummy difference (trange) must be ginned up to
692
 * correspond to the change reported in the other file.
693
 */
694
static void
695
keep(int i, struct range *rnew)
696
{
697
	int delta;
698
	struct range trange;
699
700
	delta = last[3] - last[i];
701
	trange.from = rnew->from - delta;
702
	trange.to = rnew->to - delta;
703
	change(i, &trange, 1);
704
}
705
706
/*
707
 * skip to just before line number from in file "i".  If "pr" is non-NULL,
708
 * print all skipped stuff with string pr as a prefix.
709
 */
710
static int
711
skip(int i, int from, char *pr)
712
{
713
	size_t j, n;
714
	char *line;
715
716
	for (n = 0; cline[i] < from - 1; n += j) {
717
		if ((line = get_line(fp[i], &j)) == NULL)
718
			return (-1);
719
		if (pr != NULL)
720
			diff_output("%s%s", pr, line);
721
		cline[i]++;
722
	}
723
	return ((int) n);
724
}
725
726
/*
727
 * Return 1 or 0 according as the old range (in file 1) contains exactly
728
 * the same data as the new range (in file 2).
729
 */
730
static int
731
duplicate(struct range *r1, struct range *r2)
732
{
733
	int c,d;
734
	int nchar;
735
	int nline;
736
737
	if (r1->to-r1->from != r2->to-r2->from)
738
		return (0);
739
	(void)skip(0, r1->from, NULL);
740
	(void)skip(1, r2->from, NULL);
741
	nchar = 0;
742
	for (nline=0; nline < r1->to - r1->from; nline++) {
743
		do {
744
			c = getc(fp[0]);
745
			d = getc(fp[1]);
746
			if (c == -1 || d== -1)
747
				return (-1);
748
			nchar++;
749
			if (c != d) {
750
				repos(nchar);
751
				return (0);
752
			}
753
		} while (c != '\n');
754
	}
755
	repos(nchar);
756
	return (1);
757
}
758
759
static void
760
repos(int nchar)
761
{
762
	int i;
763
764
	for (i = 0; i < 2; i++)
765
		(void)fseek(fp[i], (long)-nchar, SEEK_CUR);
766
}
767
768
/*
769
 * collect an editing script for later regurgitation
770
 */
771
static int
772
edit(struct diff *diff, int fdup, int j)
773
{
774
	if (((fdup + 1) & eflag) == 0)
775
		return (j);
776
	j++;
777
	overlap[j] = !fdup;
778
	if (!fdup)
779
		overlapcnt++;
780
	de[j].old.from = diff->old.from;
781
	de[j].old.to = diff->old.to;
782
	de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
783
	de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
784
	return (j);
785
}
786
787
/* regurgitate */
788
static int
789
edscript(int n)
790
{
791
	int j, k;
792
	char block[BUFSIZ+1];
793
794
	for (; n > 0; n--) {
795
		if (!oflag || !overlap[n])
796
			prange(&de[n].old);
797
		else
798
			diff_output("%da\n=======\n", de[n].old.to -1);
799
		(void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);
800
		for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
801
			j = k > BUFSIZ ? BUFSIZ : k;
802
			if (fread(block, 1, j, fp[2]) != (size_t)j)
803
				return (-1);
804
			block[j] = '\0';
805
			diff_output("%s", block);
806
		}
807
808
		if (!oflag || !overlap[n])
809
			diff_output(".\n");
810
		else {
811
			diff_output("%s\n.\n", f3mark);
812
			diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
813
		}
814
	}
815
816
	return (overlapcnt);
817
}
818
819
static void
820
increase(void)
821
{
822
	size_t newsz, incr;
823
824
	/* are the memset(3) calls needed? */
825
	newsz = szchanges == 0 ? 64 : 2 * szchanges;
826
	incr = newsz - szchanges;
827
828
	d13 = xreallocarray(d13, newsz, sizeof(*d13));
829
	memset(d13 + szchanges, 0, incr * sizeof(*d13));
830
	d23 = xreallocarray(d23, newsz, sizeof(*d23));
831
	memset(d23 + szchanges, 0, incr * sizeof(*d23));
832
	de = xreallocarray(de, newsz, sizeof(*de));
833
	memset(de + szchanges, 0, incr * sizeof(*de));
834
	overlap = xreallocarray(overlap, newsz, sizeof(*overlap));
835
	memset(overlap + szchanges, 0, incr * sizeof(*overlap));
836
	szchanges = newsz;
837
}