1 /* $OpenBSD: diff3prog.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $ */
2
3 /*
4 * SPDX-License-Identifier: Caldera-no-preamble AND BSD-3-Clause
5 *
6 * Copyright (C) Caldera International Inc. 2001-2002.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code and documentation must retain the above
13 * copyright notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed or owned by Caldera
20 * International, Inc.
21 * 4. Neither the name of Caldera International, Inc. nor the names of other
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
26 * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
30 * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
34 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
35 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38 /*-
39 * Copyright (c) 1991, 1993
40 * The Regents of the University of California. All rights reserved.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 */
66
67 #include <sys/types.h>
68 #include <sys/capsicum.h>
69 #include <sys/procdesc.h>
70 #include <sys/wait.h>
71
72 #include <assert.h>
73 #include <capsicum_helpers.h>
74 #include <ctype.h>
75 #include <err.h>
76 #include <fcntl.h>
77 #include <getopt.h>
78 #include <inttypes.h>
79 #include <limits.h>
80 #include <spawn.h>
81 #include <stdio.h>
82 #include <stdlib.h>
83 #include <string.h>
84 #include <unistd.h>
85
86 extern char **environ;
87 /*
88 * "from" is first in range of changed lines; "to" is last+1
89 * from=to=line after point of insertion for added lines.
90 */
91 struct range {
92 int from;
93 int to;
94 };
95
96 enum difftype {
97 DIFF_NONE,
98 DIFF_TYPE1,
99 DIFF_TYPE2,
100 DIFF_TYPE3,
101 };
102
103 struct diff {
104 enum difftype type;
105
106 /* Ranges as lines */
107 struct range old;
108 struct range new;
109 };
110
111 #define EFLAG_NONE 0
112 #define EFLAG_OVERLAP 1
113 #define EFLAG_NOOVERLAP 2
114 #define EFLAG_UNMERGED 3
115
116 static size_t szchanges;
117
118 static struct diff *d13;
119 static struct diff *d23;
120 /*
121 * "de" is used to gather editing scripts. These are later spewed out in
122 * reverse order. Its first element must be all zero, the "old" and "new"
123 * components of "de" contain line positions. Array overlap indicates which
124 * sections in "de" correspond to lines that are different in all three files.
125 */
126 static struct diff *de;
127 static char *overlap;
128 static int *de_delta; /* file1-file3 line number delta per edit */
129 static int overlapcnt;
130 static FILE *fp[3];
131 static int cline[3]; /* # of the last-read line in each file (0-2) */
132 /*
133 * The latest known correspondence between line numbers of the 3 files
134 * is stored in last[1-3];
135 */
136 static int last[4];
137 static int Aflag, eflag, iflag, mflag, Tflag;
138 static int oflag; /* indicates whether to mark overlaps (-E or -X) */
139 static int strip_cr;
140 static char *f1mark, *f2mark, *f3mark;
141 static const char *oldmark = "<<<<<<<";
142 static const char *orgmark = "|||||||";
143 static const char *newmark = ">>>>>>>";
144 static const char *divider = "=======";
145
146 static bool duplicate(struct range *, struct range *);
147 static int edit(struct diff *, bool, int, enum difftype);
148 static char *getchange(FILE *);
149 static char *get_line(FILE *, size_t *);
150 static int readin(int fd, struct diff **);
151 static int skip(int, int, const char *);
152 static void change(int, struct range *, bool);
153 static void keep(int, struct range *);
154 static void merge(int, int);
155 static void prange(struct range *, bool);
156 static void repos(int);
157 static void separate(const char *);
158 static void edscript(int) __dead2;
159 static void Ascript(int) __dead2;
160 static void mergescript(int, int) __dead2;
161 static void increase(void);
162 static void usage(void);
163 static void printrange(FILE *, struct range *);
164
165 static const char diff3_version[] = "FreeBSD diff3 20260213";
166
167 enum {
168 DIFFPROG_OPT,
169 STRIPCR_OPT,
170 HELP_OPT,
171 VERSION_OPT
172 };
173
174 #define DIFF_PATH "/usr/bin/diff"
175
176 #define OPTIONS "3aAeEiL:mTxX"
177 static struct option longopts[] = {
178 { "ed", no_argument, NULL, 'e' },
179 { "show-overlap", no_argument, NULL, 'E' },
180 { "overlap-only", no_argument, NULL, 'x' },
181 { "initial-tab", no_argument, NULL, 'T' },
182 { "text", no_argument, NULL, 'a' },
183 { "strip-trailing-cr", no_argument, NULL, STRIPCR_OPT },
184 { "show-all", no_argument, NULL, 'A' },
185 { "easy-only", no_argument, NULL, '3' },
186 { "merge", no_argument, NULL, 'm' },
187 { "label", required_argument, NULL, 'L' },
188 { "diff-program", required_argument, NULL, DIFFPROG_OPT },
189 { "help", no_argument, NULL, HELP_OPT},
190 { "version", no_argument, NULL, VERSION_OPT}
191 };
192
193 static void
usage(void)194 usage(void)
195 {
196 fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
197 "[-L label3] file1 file2 file3\n");
198 }
199
200 static int
strtoi(char * str,char ** end)201 strtoi(char *str, char **end)
202 {
203 intmax_t num;
204
205 errno = 0;
206 num = strtoimax(str, end, 10);
207 if ((end != NULL && *end == str) ||
208 num < 0 || num > INT_MAX ||
209 errno == EINVAL || errno == ERANGE)
210 err(2, "error in diff output");
211 return (int)num;
212 }
213
214 /*
215 * Read diff hunks into the array pointed to by *dd.
216 *
217 * The output from `diff foo bar` consists of a series of hunks describing
218 * an addition (lines in bar not present in foo), change (lines in bar
219 * different from lines in foo), or deletion (lines in foo not present in
220 * bar). Each record starts with a line of the form:
221 *
222 * a[,b]xc[,d]
223 *
224 * where a, b, c, and d are nonnegative integers (b and d are printed only
225 * if they differ from a and c, respectively), and x is either 'a' for an
226 * addition, 'c' for a change, or 'd' for a deletion. This is then
227 * followed by a series of lines (which we ignore) giving the added,
228 * changed, or deleted text.
229 *
230 * For an addition, a == b is the last line in 'foo' before the addition,
231 * while c through d is the range of lines in 'bar' to be added to 'foo'.
232 *
233 * For a change, a through b is the range of lines in 'foo' to be replaced
234 * and c through d is the range of lines in 'bar' to replace them with.
235 *
236 * For a deletion, a through b is the range of lines in 'foo' to remove
237 * and c == d is the line in 'bar' which corresponds to the last line
238 * before the deletion.
239 *
240 * The observant reader will have noticed that x is not really needed and
241 * that we can fully describe any hunk using only a, b, c, and d:
242 *
243 * - an addition replaces a zero-length range in one file with a
244 * non-zero-length range from the other
245 *
246 * - a change replaces a non-zero-length range in one file with a
247 * non-zero-length range from the other
248 *
249 * - a deletion replaces a non-zero-length range in one file with a
250 * zero-length range from the other
251 */
252 static int
readin(int fd,struct diff ** dd)253 readin(int fd, struct diff **dd)
254 {
255 int a, b, c, d;
256 int i;
257 char kind, *p;
258 FILE *f;
259
260 f = fdopen(fd, "r");
261 if (f == NULL)
262 err(2, "fdopen");
263 for (i = 0; (p = getchange(f)) != NULL; i++) {
264 if ((size_t)i >= szchanges - 1)
265 increase();
266
267 a = b = strtoi(p, &p);
268 if (*p == ',')
269 b = strtoi(p + 1, &p);
270 kind = *p++;
271 c = d = strtoi(p, &p);
272 if (*p == ',')
273 d = strtoi(p + 1, &p);
274 if (*p != '\n')
275 errx(2, "error in diff output");
276 if (kind == 'a')
277 a++;
278 else if (kind == 'c')
279 /* nothing */ ;
280 else if (kind == 'd')
281 c++;
282 else
283 errx(2, "error in diff output");
284 b++;
285 d++;
286 if (b < a || d < c)
287 errx(2, "error in diff output");
288 (*dd)[i].old.from = a;
289 (*dd)[i].old.to = b;
290 (*dd)[i].new.from = c;
291 (*dd)[i].new.to = d;
292 if (i > 0) {
293 if ((*dd)[i].old.from < (*dd)[i - 1].old.to ||
294 (*dd)[i].new.from < (*dd)[i - 1].new.to)
295 errx(2, "diff output out of order");
296 }
297 }
298 if (i > 0) {
299 (*dd)[i].old.from = (*dd)[i].old.to = (*dd)[i - 1].old.to;
300 (*dd)[i].new.from = (*dd)[i].new.to = (*dd)[i - 1].new.to;
301 }
302 fclose(f);
303 return (i);
304 }
305
306 static int
diffexec(char ** diffargv,int fd[])307 diffexec(char **diffargv, int fd[])
308 {
309 posix_spawnattr_t sa;
310 posix_spawn_file_actions_t fa;
311 pid_t pid;
312 int pd, error;
313
314 if ((error = posix_spawnattr_init(&sa)) != 0)
315 errc(2, error, "posix_spawnattr_init");
316 if ((error = posix_spawn_file_actions_init(&fa)) != 0)
317 errc(2, error, "posix_spawn_file_actions_init");
318
319 posix_spawnattr_setprocdescp_np(&sa, &pd, 0);
320 posix_spawn_file_actions_adddup2(&fa, fd[1], STDOUT_FILENO);
321
322 error = posix_spawn(&pid, diffargv[0], &fa, &sa, diffargv, environ);
323 if (error != 0)
324 errc(2, error, "could not spawn diff");
325
326 posix_spawn_file_actions_destroy(&fa);
327 posix_spawnattr_destroy(&sa);
328 close(fd[1]);
329 return (pd);
330 }
331
332 static char *
getchange(FILE * b)333 getchange(FILE *b)
334 {
335 char *line;
336
337 while ((line = get_line(b, NULL)) != NULL) {
338 if (isdigit((unsigned char)line[0]))
339 return (line);
340 }
341 return (NULL);
342 }
343
344
345 static char *
get_line(FILE * b,size_t * n)346 get_line(FILE *b, size_t *n)
347 {
348 ssize_t len;
349 static char *buf = NULL;
350 static size_t bufsize = 0;
351
352 if ((len = getline(&buf, &bufsize, b)) < 0)
353 return (NULL);
354
355 if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
356 buf[len - 2] = '\n';
357 buf[len - 1] = '\0';
358 len--;
359 }
360
361 if (n != NULL)
362 *n = len;
363
364 return (buf);
365 }
366
367 static void
merge(int m1,int m2)368 merge(int m1, int m2)
369 {
370 struct diff *d1, *d2, *d3;
371 int j, t1, t2;
372 int f1f3delta;
373 bool dup = false;
374
375 d1 = d13;
376 d2 = d23;
377 j = 0;
378 f1f3delta = 0;
379
380 for (;;) {
381 t1 = (d1 < d13 + m1);
382 t2 = (d2 < d23 + m2);
383 if (!t1 && !t2)
384 break;
385
386 /* first file is different from the others */
387 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
388 /* stuff peculiar to 1st file */
389 if (eflag == EFLAG_NONE) {
390 separate("1");
391 change(1, &d1->old, false);
392 keep(2, &d1->new);
393 change(3, &d1->new, false);
394 } else if (mflag) {
395 j++;
396 de[j].type = DIFF_TYPE1;
397 de[j].old = d1->old;
398 de[j].new = d1->new;
399 overlap[j] = 0;
400 } else if (eflag == EFLAG_OVERLAP) {
401 j = edit(d2, dup, j, DIFF_TYPE1);
402 }
403 f1f3delta += (d1->old.to - d1->old.from) -
404 (d1->new.to - d1->new.from);
405 d1++;
406 continue;
407 }
408 /* second file is different from others */
409 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
410 if (eflag == EFLAG_NONE) {
411 separate("2");
412 keep(1, &d2->new);
413 change(3, &d2->new, false);
414 change(2, &d2->old, false);
415 } else if (Aflag || mflag) {
416 if (eflag == EFLAG_UNMERGED) {
417 j = edit(d2, dup, j, DIFF_TYPE2);
418 de_delta[j] = f1f3delta;
419 }
420 }
421 d2++;
422 continue;
423 }
424 /*
425 * Merge overlapping changes in first file
426 * this happens after extension (see below).
427 */
428 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
429 d1[1].old.from = d1->old.from;
430 d1[1].new.from = d1->new.from;
431 d1++;
432 continue;
433 }
434
435 /* merge overlapping changes in second */
436 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
437 d2[1].old.from = d2->old.from;
438 d2[1].new.from = d2->new.from;
439 d2++;
440 continue;
441 }
442 /* stuff peculiar to third file or different in all */
443 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
444 dup = duplicate(&d1->old, &d2->old);
445 /*
446 * dup = 0 means all files differ
447 * dup = 1 means files 1 and 2 identical
448 */
449 if (eflag == EFLAG_NONE) {
450 separate(dup ? "3" : "");
451 change(1, &d1->old, dup);
452 change(2, &d2->old, false);
453 d3 = d1->old.to > d1->old.from ? d1 : d2;
454 change(3, &d3->new, false);
455 } else if (mflag) {
456 j++;
457 de[j].type = DIFF_TYPE3;
458 de[j].old = d1->old;
459 de[j].new = d1->new;
460 overlap[j] = !dup;
461 if (!dup)
462 overlapcnt++;
463 } else {
464 j = edit(d1, dup, j, DIFF_TYPE3);
465 }
466 dup = false;
467 f1f3delta += (d1->old.to - d1->old.from) -
468 (d1->new.to - d1->new.from);
469 d1++;
470 d2++;
471 continue;
472 }
473 /*
474 * Overlapping changes from file 1 and 2; extend changes
475 * appropriately to make them coincide.
476 */
477 if (d1->new.from < d2->new.from) {
478 d2->old.from -= d2->new.from - d1->new.from;
479 d2->new.from = d1->new.from;
480 } else if (d2->new.from < d1->new.from) {
481 d1->old.from -= d1->new.from - d2->new.from;
482 d1->new.from = d2->new.from;
483 }
484 if (d1->new.to > d2->new.to) {
485 d2->old.to += d1->new.to - d2->new.to;
486 d2->new.to = d1->new.to;
487 } else if (d2->new.to > d1->new.to) {
488 d1->old.to += d2->new.to - d1->new.to;
489 d1->new.to = d2->new.to;
490 }
491 }
492
493 if (mflag)
494 mergescript(j, f1f3delta);
495 else if (Aflag)
496 Ascript(j);
497 else if (eflag)
498 edscript(j);
499 }
500
501 static void
separate(const char * s)502 separate(const char *s)
503 {
504 printf("====%s\n", s);
505 }
506
507 /*
508 * The range of lines rold.from thru rold.to in file i is to be changed.
509 * It is to be printed only if it does not duplicate something to be
510 * printed later.
511 */
512 static void
change(int i,struct range * rold,bool dup)513 change(int i, struct range *rold, bool dup)
514 {
515
516 printf("%d:", i);
517 last[i] = rold->to;
518 prange(rold, false);
519 if (dup)
520 return;
521 i--;
522 skip(i, rold->from, NULL);
523 skip(i, rold->to, " ");
524 }
525
526 /*
527 * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
528 * n1.
529 */
530 static void
prange(struct range * rold,bool delete)531 prange(struct range *rold, bool delete)
532 {
533
534 if (rold->to <= rold->from)
535 printf("%da\n", rold->from - 1);
536 else {
537 printf("%d", rold->from);
538 if (rold->to > rold->from + 1)
539 printf(",%d", rold->to - 1);
540 if (delete)
541 printf("d\n");
542 else
543 printf("c\n");
544 }
545 }
546
547 /*
548 * No difference was reported by diff between file 1 (or 2) and file 3,
549 * and an artificial dummy difference (trange) must be ginned up to
550 * correspond to the change reported in the other file.
551 */
552 static void
keep(int i,struct range * rnew)553 keep(int i, struct range *rnew)
554 {
555 int delta;
556 struct range trange;
557
558 delta = last[3] - last[i];
559 trange.from = rnew->from - delta;
560 trange.to = rnew->to - delta;
561 change(i, &trange, true);
562 }
563
564 /*
565 * skip to just before line number from in file "i". If "pr" is non-NULL,
566 * print all skipped stuff with string pr as a prefix.
567 */
568 static int
skip(int i,int from,const char * pr)569 skip(int i, int from, const char *pr)
570 {
571 size_t j, n;
572 char *line;
573
574 for (n = 0; cline[i] < from - 1; n += j) {
575 if ((line = get_line(fp[i], &j)) == NULL)
576 errx(2, "logic error");
577 if (pr != NULL)
578 printf("%s%s", Tflag == 1 ? "\t" : pr, line);
579 cline[i]++;
580 }
581 return ((int) n);
582 }
583
584 /*
585 * Return 1 or 0 according as the old range (in file 1) contains exactly
586 * the same data as the new range (in file 2).
587 */
588 static bool
duplicate(struct range * r1,struct range * r2)589 duplicate(struct range *r1, struct range *r2)
590 {
591 int c, d;
592 int nchar;
593 int nline;
594
595 if (r1->to-r1->from != r2->to-r2->from)
596 return (0);
597 skip(0, r1->from, NULL);
598 skip(1, r2->from, NULL);
599 nchar = 0;
600 for (nline = 0; nline < r1->to - r1->from; nline++) {
601 do {
602 c = getc(fp[0]);
603 d = getc(fp[1]);
604 if (c == -1 && d == -1)
605 break;
606 if (c == -1 || d == -1)
607 errx(2, "logic error");
608 nchar++;
609 if (c != d) {
610 repos(nchar);
611 return (0);
612 }
613 } while (c != '\n');
614 }
615 repos(nchar);
616 return (1);
617 }
618
619 static void
repos(int nchar)620 repos(int nchar)
621 {
622 int i;
623
624 for (i = 0; i < 2; i++)
625 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
626 }
627
628 /*
629 * collect an editing script for later regurgitation
630 */
631 static int
edit(struct diff * diff,bool dup,int j,enum difftype difftype)632 edit(struct diff *diff, bool dup, int j, enum difftype difftype)
633 {
634 if (!(eflag == EFLAG_UNMERGED ||
635 (!dup && eflag == EFLAG_OVERLAP ) ||
636 (dup && eflag == EFLAG_NOOVERLAP))) {
637 return (j);
638 }
639 j++;
640 overlap[j] = !dup;
641 if (!dup)
642 overlapcnt++;
643
644 de[j].type = difftype;
645 de[j].old.from = diff->old.from;
646 de[j].old.to = diff->old.to;
647 de[j].new.from = diff->new.from;
648 de[j].new.to = diff->new.to;
649 return (j);
650 }
651
652 static void
printrange(FILE * p,struct range * r)653 printrange(FILE *p, struct range *r)
654 {
655 char *line = NULL;
656 size_t len = 0;
657 int i = 1;
658
659 /* We haven't been asked to print anything */
660 if (r->from == r->to)
661 return;
662
663 if (r->from > r->to)
664 errx(2, "invalid print range");
665
666 /*
667 * XXX-THJ: We read through all of the file for each range printed.
668 * This duplicates work and will probably impact performance on large
669 * files with lots of ranges.
670 */
671 fseek(p, 0L, SEEK_SET);
672 while (getline(&line, &len, p) > 0) {
673 if (i >= r->from)
674 printf("%s", line);
675 if (++i > r->to - 1)
676 break;
677 }
678 free(line);
679 }
680
681 /* regurgitate */
682 static void
edscript(int n)683 edscript(int n)
684 {
685 bool delete;
686 struct range *new, *old;
687
688 for (; n > 0; n--) {
689 new = &de[n].new;
690 old = &de[n].old;
691
692 delete = (new->from == new->to);
693 if (de[n].type == DIFF_TYPE1) {
694 if (delete)
695 printf("%dd\n", new->from - 1);
696 else if (old->from == new->from && old->to == new->to) {
697 printf("%dc\n", old->from);
698 printrange(fp[2], old);
699 printf(".\n");
700 }
701 continue;
702 } else {
703 if (!oflag || !overlap[n]) {
704 prange(old, delete);
705 } else {
706 printf("%da\n", old->to - 1);
707 printf("%s\n", divider);
708 }
709 printrange(fp[2], new);
710 if (!oflag || !overlap[n]) {
711 if (!delete)
712 printf(".\n");
713 } else {
714 printf("%s %s\n.\n", newmark, f3mark);
715 printf("%da\n%s %s\n.\n", old->from - 1,
716 oldmark, f1mark);
717 }
718 }
719 }
720 if (iflag)
721 printf("w\nq\n");
722
723 exit(oflag ? overlapcnt > 0 : 0);
724 }
725
726 /*
727 * Output an edit script to turn mine into yours, when there is a conflict
728 * between the 3 files bracket the changes. Regurgitate the diffs in reverse
729 * order to allow the ed script to track down where the lines are as changes
730 * are made.
731 */
732 static void
Ascript(int n)733 Ascript(int n)
734 {
735 int startmark;
736 bool deletenew;
737 bool deleteold;
738
739 struct range *new, *old;
740
741 for (; n > 0; n--) {
742 new = &de[n].new;
743 old = &de[n].old;
744 deletenew = (new->from == new->to);
745 deleteold = (old->from == old->to);
746
747 if (de[n].type == DIFF_TYPE2) {
748 if (!oflag || !overlap[n]) {
749 prange(old, deletenew);
750 printrange(fp[2], new);
751 } else {
752 startmark = new->to - 1 + de_delta[n];
753
754 printf("%da\n", startmark);
755 printf("%s %s\n", newmark, f3mark);
756
757 printf(".\n");
758
759 printf("%da\n", startmark -
760 (new->to - new->from));
761 printf("%s %s\n", oldmark, f2mark);
762 if (!deleteold)
763 printrange(fp[1], old);
764 printf("%s\n.\n", divider);
765 }
766
767 } else if (de[n].type == DIFF_TYPE3) {
768 startmark = old->to - 1;
769
770 if (!oflag || !overlap[n]) {
771 prange(old, deletenew);
772 printrange(fp[2], new);
773 } else {
774 printf("%da\n", startmark);
775 printf("%s %s\n", orgmark, f2mark);
776
777 if (deleteold) {
778 struct range r;
779 r.from = old->from-1;
780 r.to = new->to;
781 printrange(fp[1], &r);
782 } else
783 printrange(fp[1], old);
784
785 printf("%s\n", divider);
786 printrange(fp[2], new);
787 }
788
789 if (!oflag || !overlap[n]) {
790 if (!deletenew)
791 printf(".\n");
792 } else {
793 printf("%s %s\n.\n", newmark, f3mark);
794
795 /*
796 * Go to the start of the conflict in original
797 * file and append lines
798 */
799 printf("%da\n%s %s\n.\n",
800 startmark - (old->to - old->from),
801 oldmark, f1mark);
802 }
803 }
804 }
805 if (iflag)
806 printf("w\nq\n");
807
808 exit(overlapcnt > 0);
809 }
810
811 /*
812 * Output the merged file directly (don't generate an ed script). When
813 * regurgitating diffs we need to walk forward through the file and print any
814 * inbetween lines.
815 */
816 static void
mergescript(int i,int f1f3delta)817 mergescript(int i, int f1f3delta)
818 {
819 struct range r, *new, *old;
820 int n;
821
822 r.from = 1;
823 r.to = 1;
824
825 for (n = 1; n <= i; n++) {
826 new = &de[n].new;
827 old = &de[n].old;
828
829 /*
830 * Print any lines leading up to here. If we are merging don't
831 * print deleted ranges.
832 */
833 if (de[n].type == DIFF_TYPE1)
834 r.to = old->to;
835 else if (de[n].type == DIFF_TYPE2)
836 r.to = new->from + de_delta[n];
837 else
838 r.to = old->from;
839
840 printrange(fp[0], &r);
841 switch (de[n].type) {
842 case DIFF_TYPE1:
843 /* Content included in "between" printing from fp[0] */
844 break;
845 case DIFF_TYPE2:
846 printf("%s %s\n", oldmark, f2mark);
847 printrange(fp[1], old);
848 printf("%s\n", divider);
849 printrange(fp[2], new);
850 printf("%s %s\n", newmark, f3mark);
851 break;
852 case DIFF_TYPE3:
853 if (!oflag || !overlap[n]) {
854 printrange(fp[2], new);
855 } else {
856
857 printf("%s %s\n", oldmark, f1mark);
858 printrange(fp[0], old);
859
860 if (eflag != EFLAG_OVERLAP) {
861 printf("%s %s\n", orgmark, f2mark);
862 if (old->from == old->to) {
863 struct range or;
864 or.from = old->from - 1;
865 or.to = new->to;
866 printrange(fp[1], &or);
867 } else {
868 printrange(fp[1], old);
869 }
870 }
871
872 printf("%s\n", divider);
873
874 printrange(fp[2], new);
875 printf("%s %s\n", newmark, f3mark);
876 }
877 break;
878 default:
879 __assert_unreachable();
880 }
881
882 if (de[n].type == DIFF_TYPE2)
883 r.from = new->to + de_delta[n];
884 else
885 r.from = old->to;
886 }
887
888 /*
889 * Print from the final range to the end of 'myfile'. Any deletions or
890 * additions to this file should have been handled by now.
891 */
892 r.from -= f1f3delta;
893 r.to = INT_MAX;
894 printrange(fp[2], &r);
895 exit(overlapcnt > 0);
896 }
897
898 static void
increase(void)899 increase(void)
900 {
901 struct diff *p;
902 char *q;
903 int *s;
904 size_t newsz, incr;
905
906 /* are the memset(3) calls needed? */
907 newsz = szchanges == 0 ? 64 : 2 * szchanges;
908 incr = newsz - szchanges;
909
910 p = reallocarray(d13, newsz, sizeof(*p));
911 if (p == NULL)
912 err(2, NULL);
913 memset(p + szchanges, 0, incr * sizeof(*p));
914 d13 = p;
915 p = reallocarray(d23, newsz, sizeof(*p));
916 if (p == NULL)
917 err(2, NULL);
918 memset(p + szchanges, 0, incr * sizeof(*p));
919 d23 = p;
920 p = reallocarray(de, newsz, sizeof(*p));
921 if (p == NULL)
922 err(2, NULL);
923 memset(p + szchanges, 0, incr * sizeof(*p));
924 de = p;
925 q = reallocarray(overlap, newsz, 1);
926 if (q == NULL)
927 err(2, NULL);
928 memset(q + szchanges, 0, incr * 1);
929 overlap = q;
930 s = reallocarray(de_delta, newsz, sizeof(*s));
931 if (s == NULL)
932 err(2, NULL);
933 memset(s + szchanges, 0, incr * sizeof(*s));
934 de_delta = s;
935 szchanges = newsz;
936 }
937
938 static void
wait_and_check(int pd)939 wait_and_check(int pd)
940 {
941 int status;
942
943 while (pdwait(pd, &status, WEXITED, NULL, NULL) == -1) {
944 if (errno != EINTR)
945 err(2, "pdwait");
946 }
947 close(pd);
948
949 if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
950 errx(2, "diff exited abnormally");
951 if (WIFSIGNALED(status))
952 errx(2, "diff killed by signal %d", WTERMSIG(status));
953 }
954
955 int
main(int argc,char ** argv)956 main(int argc, char **argv)
957 {
958 int ch, nblabels, m, n;
959 char *labels[] = { NULL, NULL, NULL };
960 const char *diffprog = DIFF_PATH;
961 char *file1, *file2, *file3;
962 char *diffargv[7];
963 int diffargc = 0;
964 int fd13[2], fd23[2];
965 int pd13, pd23;
966 cap_rights_t rights_ro;
967
968 nblabels = 0;
969 eflag = EFLAG_NONE;
970 oflag = 0;
971 diffargv[diffargc++] = __DECONST(char *, diffprog);
972 while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
973 switch (ch) {
974 case '3':
975 eflag = EFLAG_NOOVERLAP;
976 break;
977 case 'a':
978 diffargv[diffargc++] = __DECONST(char *, "-a");
979 break;
980 case 'A':
981 Aflag = 1;
982 break;
983 case 'e':
984 eflag = EFLAG_UNMERGED;
985 break;
986 case 'E':
987 eflag = EFLAG_OVERLAP;
988 oflag = 1;
989 break;
990 case 'i':
991 iflag = 1;
992 break;
993 case 'L':
994 oflag = 1;
995 if (nblabels >= 3)
996 errx(2, "too many file label options");
997 labels[nblabels++] = optarg;
998 break;
999 case 'm':
1000 Aflag = 1;
1001 oflag = 1;
1002 mflag = 1;
1003 break;
1004 case 'T':
1005 Tflag = 1;
1006 break;
1007 case 'x':
1008 eflag = EFLAG_OVERLAP;
1009 break;
1010 case 'X':
1011 oflag = 1;
1012 eflag = EFLAG_OVERLAP;
1013 break;
1014 case DIFFPROG_OPT:
1015 diffargv[0] = optarg;
1016 break;
1017 case STRIPCR_OPT:
1018 strip_cr = 1;
1019 diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
1020 break;
1021 case HELP_OPT:
1022 usage();
1023 exit(0);
1024 case VERSION_OPT:
1025 printf("%s\n", diff3_version);
1026 exit(0);
1027 }
1028 }
1029 argc -= optind;
1030 argv += optind;
1031
1032 if (Aflag) {
1033 if (eflag == EFLAG_NONE)
1034 eflag = EFLAG_UNMERGED;
1035 oflag = 1;
1036 }
1037
1038 if (argc != 3) {
1039 usage();
1040 exit(2);
1041 }
1042
1043 if (caph_limit_stdio() == -1)
1044 err(2, "unable to limit stdio");
1045
1046 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
1047
1048 /* TODO stdio */
1049 file1 = argv[0];
1050 file2 = argv[1];
1051 file3 = argv[2];
1052
1053 if (oflag) {
1054 asprintf(&f1mark, "%s",
1055 labels[0] != NULL ? labels[0] : file1);
1056 if (f1mark == NULL)
1057 err(2, "asprintf");
1058 asprintf(&f2mark, "%s",
1059 labels[1] != NULL ? labels[1] : file2);
1060 if (f2mark == NULL)
1061 err(2, "asprintf");
1062 asprintf(&f3mark, "%s",
1063 labels[2] != NULL ? labels[2] : file3);
1064 if (f3mark == NULL)
1065 err(2, "asprintf");
1066 }
1067 fp[0] = fopen(file1, "r");
1068 if (fp[0] == NULL)
1069 err(2, "Can't open %s", file1);
1070 if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
1071 err(2, "unable to limit rights on: %s", file1);
1072
1073 fp[1] = fopen(file2, "r");
1074 if (fp[1] == NULL)
1075 err(2, "Can't open %s", file2);
1076 if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
1077 err(2, "unable to limit rights on: %s", file2);
1078
1079 fp[2] = fopen(file3, "r");
1080 if (fp[2] == NULL)
1081 err(2, "Can't open %s", file3);
1082 if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
1083 err(2, "unable to limit rights on: %s", file3);
1084
1085 if (pipe2(fd13, O_CLOEXEC))
1086 err(2, "pipe");
1087 if (pipe2(fd23, O_CLOEXEC))
1088 err(2, "pipe");
1089
1090 diffargv[diffargc] = file1;
1091 diffargv[diffargc + 1] = file3;
1092 diffargv[diffargc + 2] = NULL;
1093 pd13 = diffexec(diffargv, fd13);
1094
1095 diffargv[diffargc] = file2;
1096 pd23 = diffexec(diffargv, fd23);
1097
1098 caph_cache_catpages();
1099 if (caph_enter() < 0)
1100 err(2, "unable to enter capability mode");
1101
1102 /* parse diffs */
1103 increase();
1104 m = readin(fd13[0], &d13);
1105 n = readin(fd23[0], &d23);
1106
1107 wait_and_check(pd13);
1108 wait_and_check(pd23);
1109
1110 merge(m, n);
1111
1112 exit(0);
1113 }
1114