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
321 posix_spawn_file_actions_addclose(&fa, fd[0]);
322 posix_spawn_file_actions_adddup2(&fa, fd[1], STDOUT_FILENO);
323 posix_spawn_file_actions_addclose(&fa, fd[1]);
324
325 error = posix_spawn(&pid, diffargv[0], &fa, &sa, diffargv, environ);
326 if (error != 0)
327 errc(2, error, "could not spawn diff");
328
329 posix_spawn_file_actions_destroy(&fa);
330 posix_spawnattr_destroy(&sa);
331 close(fd[1]);
332 return (pd);
333 }
334
335 static char *
getchange(FILE * b)336 getchange(FILE *b)
337 {
338 char *line;
339
340 while ((line = get_line(b, NULL)) != NULL) {
341 if (isdigit((unsigned char)line[0]))
342 return (line);
343 }
344 return (NULL);
345 }
346
347
348 static char *
get_line(FILE * b,size_t * n)349 get_line(FILE *b, size_t *n)
350 {
351 ssize_t len;
352 static char *buf = NULL;
353 static size_t bufsize = 0;
354
355 if ((len = getline(&buf, &bufsize, b)) < 0)
356 return (NULL);
357
358 if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
359 buf[len - 2] = '\n';
360 buf[len - 1] = '\0';
361 len--;
362 }
363
364 if (n != NULL)
365 *n = len;
366
367 return (buf);
368 }
369
370 static void
merge(int m1,int m2)371 merge(int m1, int m2)
372 {
373 struct diff *d1, *d2, *d3;
374 int j, t1, t2;
375 int f1f3delta;
376 bool dup = false;
377
378 d1 = d13;
379 d2 = d23;
380 j = 0;
381 f1f3delta = 0;
382
383 for (;;) {
384 t1 = (d1 < d13 + m1);
385 t2 = (d2 < d23 + m2);
386 if (!t1 && !t2)
387 break;
388
389 /* first file is different from the others */
390 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
391 /* stuff peculiar to 1st file */
392 if (eflag == EFLAG_NONE) {
393 separate("1");
394 change(1, &d1->old, false);
395 keep(2, &d1->new);
396 change(3, &d1->new, false);
397 } else if (mflag) {
398 j++;
399 de[j].type = DIFF_TYPE1;
400 de[j].old = d1->old;
401 de[j].new = d1->new;
402 overlap[j] = 0;
403 } else if (eflag == EFLAG_OVERLAP) {
404 j = edit(d2, dup, j, DIFF_TYPE1);
405 }
406 f1f3delta += (d1->old.to - d1->old.from) -
407 (d1->new.to - d1->new.from);
408 d1++;
409 continue;
410 }
411 /* second file is different from others */
412 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
413 if (eflag == EFLAG_NONE) {
414 separate("2");
415 keep(1, &d2->new);
416 change(3, &d2->new, false);
417 change(2, &d2->old, false);
418 } else if (Aflag || mflag) {
419 if (eflag == EFLAG_UNMERGED) {
420 j = edit(d2, dup, j, DIFF_TYPE2);
421 de_delta[j] = f1f3delta;
422 }
423 }
424 d2++;
425 continue;
426 }
427 /*
428 * Merge overlapping changes in first file
429 * this happens after extension (see below).
430 */
431 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
432 d1[1].old.from = d1->old.from;
433 d1[1].new.from = d1->new.from;
434 d1++;
435 continue;
436 }
437
438 /* merge overlapping changes in second */
439 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
440 d2[1].old.from = d2->old.from;
441 d2[1].new.from = d2->new.from;
442 d2++;
443 continue;
444 }
445 /* stuff peculiar to third file or different in all */
446 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
447 dup = duplicate(&d1->old, &d2->old);
448 /*
449 * dup = 0 means all files differ
450 * dup = 1 means files 1 and 2 identical
451 */
452 if (eflag == EFLAG_NONE) {
453 separate(dup ? "3" : "");
454 change(1, &d1->old, dup);
455 change(2, &d2->old, false);
456 d3 = d1->old.to > d1->old.from ? d1 : d2;
457 change(3, &d3->new, false);
458 } else if (mflag) {
459 j++;
460 de[j].type = DIFF_TYPE3;
461 de[j].old = d1->old;
462 de[j].new = d1->new;
463 overlap[j] = !dup;
464 if (!dup)
465 overlapcnt++;
466 } else {
467 j = edit(d1, dup, j, DIFF_TYPE3);
468 }
469 dup = false;
470 f1f3delta += (d1->old.to - d1->old.from) -
471 (d1->new.to - d1->new.from);
472 d1++;
473 d2++;
474 continue;
475 }
476 /*
477 * Overlapping changes from file 1 and 2; extend changes
478 * appropriately to make them coincide.
479 */
480 if (d1->new.from < d2->new.from) {
481 d2->old.from -= d2->new.from - d1->new.from;
482 d2->new.from = d1->new.from;
483 } else if (d2->new.from < d1->new.from) {
484 d1->old.from -= d1->new.from - d2->new.from;
485 d1->new.from = d2->new.from;
486 }
487 if (d1->new.to > d2->new.to) {
488 d2->old.to += d1->new.to - d2->new.to;
489 d2->new.to = d1->new.to;
490 } else if (d2->new.to > d1->new.to) {
491 d1->old.to += d2->new.to - d1->new.to;
492 d1->new.to = d2->new.to;
493 }
494 }
495
496 if (mflag)
497 mergescript(j, f1f3delta);
498 else if (Aflag)
499 Ascript(j);
500 else if (eflag)
501 edscript(j);
502 }
503
504 static void
separate(const char * s)505 separate(const char *s)
506 {
507 printf("====%s\n", s);
508 }
509
510 /*
511 * The range of lines rold.from thru rold.to in file i is to be changed.
512 * It is to be printed only if it does not duplicate something to be
513 * printed later.
514 */
515 static void
change(int i,struct range * rold,bool dup)516 change(int i, struct range *rold, bool dup)
517 {
518
519 printf("%d:", i);
520 last[i] = rold->to;
521 prange(rold, false);
522 if (dup)
523 return;
524 i--;
525 skip(i, rold->from, NULL);
526 skip(i, rold->to, " ");
527 }
528
529 /*
530 * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
531 * n1.
532 */
533 static void
prange(struct range * rold,bool delete)534 prange(struct range *rold, bool delete)
535 {
536
537 if (rold->to <= rold->from)
538 printf("%da\n", rold->from - 1);
539 else {
540 printf("%d", rold->from);
541 if (rold->to > rold->from + 1)
542 printf(",%d", rold->to - 1);
543 if (delete)
544 printf("d\n");
545 else
546 printf("c\n");
547 }
548 }
549
550 /*
551 * No difference was reported by diff between file 1 (or 2) and file 3,
552 * and an artificial dummy difference (trange) must be ginned up to
553 * correspond to the change reported in the other file.
554 */
555 static void
keep(int i,struct range * rnew)556 keep(int i, struct range *rnew)
557 {
558 int delta;
559 struct range trange;
560
561 delta = last[3] - last[i];
562 trange.from = rnew->from - delta;
563 trange.to = rnew->to - delta;
564 change(i, &trange, true);
565 }
566
567 /*
568 * skip to just before line number from in file "i". If "pr" is non-NULL,
569 * print all skipped stuff with string pr as a prefix.
570 */
571 static int
skip(int i,int from,const char * pr)572 skip(int i, int from, const char *pr)
573 {
574 size_t j, n;
575 char *line;
576
577 for (n = 0; cline[i] < from - 1; n += j) {
578 if ((line = get_line(fp[i], &j)) == NULL)
579 errx(2, "logic error");
580 if (pr != NULL)
581 printf("%s%s", Tflag == 1 ? "\t" : pr, line);
582 cline[i]++;
583 }
584 return ((int) n);
585 }
586
587 /*
588 * Return 1 or 0 according as the old range (in file 1) contains exactly
589 * the same data as the new range (in file 2).
590 */
591 static bool
duplicate(struct range * r1,struct range * r2)592 duplicate(struct range *r1, struct range *r2)
593 {
594 int c, d;
595 int nchar;
596 int nline;
597
598 if (r1->to-r1->from != r2->to-r2->from)
599 return (0);
600 skip(0, r1->from, NULL);
601 skip(1, r2->from, NULL);
602 nchar = 0;
603 for (nline = 0; nline < r1->to - r1->from; nline++) {
604 do {
605 c = getc(fp[0]);
606 d = getc(fp[1]);
607 if (c == -1 && d == -1)
608 break;
609 if (c == -1 || d == -1)
610 errx(2, "logic error");
611 nchar++;
612 if (c != d) {
613 repos(nchar);
614 return (0);
615 }
616 } while (c != '\n');
617 }
618 repos(nchar);
619 return (1);
620 }
621
622 static void
repos(int nchar)623 repos(int nchar)
624 {
625 int i;
626
627 for (i = 0; i < 2; i++)
628 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
629 }
630
631 /*
632 * collect an editing script for later regurgitation
633 */
634 static int
edit(struct diff * diff,bool dup,int j,enum difftype difftype)635 edit(struct diff *diff, bool dup, int j, enum difftype difftype)
636 {
637 if (!(eflag == EFLAG_UNMERGED ||
638 (!dup && eflag == EFLAG_OVERLAP ) ||
639 (dup && eflag == EFLAG_NOOVERLAP))) {
640 return (j);
641 }
642 j++;
643 overlap[j] = !dup;
644 if (!dup)
645 overlapcnt++;
646
647 de[j].type = difftype;
648 de[j].old.from = diff->old.from;
649 de[j].old.to = diff->old.to;
650 de[j].new.from = diff->new.from;
651 de[j].new.to = diff->new.to;
652 return (j);
653 }
654
655 static void
printrange(FILE * p,struct range * r)656 printrange(FILE *p, struct range *r)
657 {
658 char *line = NULL;
659 size_t len = 0;
660 int i = 1;
661
662 /* We haven't been asked to print anything */
663 if (r->from == r->to)
664 return;
665
666 if (r->from > r->to)
667 errx(2, "invalid print range");
668
669 /*
670 * XXX-THJ: We read through all of the file for each range printed.
671 * This duplicates work and will probably impact performance on large
672 * files with lots of ranges.
673 */
674 fseek(p, 0L, SEEK_SET);
675 while (getline(&line, &len, p) > 0) {
676 if (i >= r->from)
677 printf("%s", line);
678 if (++i > r->to - 1)
679 break;
680 }
681 free(line);
682 }
683
684 /* regurgitate */
685 static void
edscript(int n)686 edscript(int n)
687 {
688 bool delete;
689 struct range *new, *old;
690
691 for (; n > 0; n--) {
692 new = &de[n].new;
693 old = &de[n].old;
694
695 delete = (new->from == new->to);
696 if (de[n].type == DIFF_TYPE1) {
697 if (delete)
698 printf("%dd\n", new->from - 1);
699 else if (old->from == new->from && old->to == new->to) {
700 printf("%dc\n", old->from);
701 printrange(fp[2], old);
702 printf(".\n");
703 }
704 continue;
705 } else {
706 if (!oflag || !overlap[n]) {
707 prange(old, delete);
708 } else {
709 printf("%da\n", old->to - 1);
710 printf("%s\n", divider);
711 }
712 printrange(fp[2], new);
713 if (!oflag || !overlap[n]) {
714 if (!delete)
715 printf(".\n");
716 } else {
717 printf("%s %s\n.\n", newmark, f3mark);
718 printf("%da\n%s %s\n.\n", old->from - 1,
719 oldmark, f1mark);
720 }
721 }
722 }
723 if (iflag)
724 printf("w\nq\n");
725
726 exit(oflag ? overlapcnt > 0 : 0);
727 }
728
729 /*
730 * Output an edit script to turn mine into yours, when there is a conflict
731 * between the 3 files bracket the changes. Regurgitate the diffs in reverse
732 * order to allow the ed script to track down where the lines are as changes
733 * are made.
734 */
735 static void
Ascript(int n)736 Ascript(int n)
737 {
738 int startmark;
739 bool deletenew;
740 bool deleteold;
741
742 struct range *new, *old;
743
744 for (; n > 0; n--) {
745 new = &de[n].new;
746 old = &de[n].old;
747 deletenew = (new->from == new->to);
748 deleteold = (old->from == old->to);
749
750 if (de[n].type == DIFF_TYPE2) {
751 if (!oflag || !overlap[n]) {
752 prange(old, deletenew);
753 printrange(fp[2], new);
754 } else {
755 startmark = new->to - 1 + de_delta[n];
756
757 printf("%da\n", startmark);
758 printf("%s %s\n", newmark, f3mark);
759
760 printf(".\n");
761
762 printf("%da\n", startmark -
763 (new->to - new->from));
764 printf("%s %s\n", oldmark, f2mark);
765 if (!deleteold)
766 printrange(fp[1], old);
767 printf("%s\n.\n", divider);
768 }
769
770 } else if (de[n].type == DIFF_TYPE3) {
771 startmark = old->to - 1;
772
773 if (!oflag || !overlap[n]) {
774 prange(old, deletenew);
775 printrange(fp[2], new);
776 } else {
777 printf("%da\n", startmark);
778 printf("%s %s\n", orgmark, f2mark);
779
780 if (deleteold) {
781 struct range r;
782 r.from = old->from-1;
783 r.to = new->to;
784 printrange(fp[1], &r);
785 } else
786 printrange(fp[1], old);
787
788 printf("%s\n", divider);
789 printrange(fp[2], new);
790 }
791
792 if (!oflag || !overlap[n]) {
793 if (!deletenew)
794 printf(".\n");
795 } else {
796 printf("%s %s\n.\n", newmark, f3mark);
797
798 /*
799 * Go to the start of the conflict in original
800 * file and append lines
801 */
802 printf("%da\n%s %s\n.\n",
803 startmark - (old->to - old->from),
804 oldmark, f1mark);
805 }
806 }
807 }
808 if (iflag)
809 printf("w\nq\n");
810
811 exit(overlapcnt > 0);
812 }
813
814 /*
815 * Output the merged file directly (don't generate an ed script). When
816 * regurgitating diffs we need to walk forward through the file and print any
817 * inbetween lines.
818 */
819 static void
mergescript(int i,int f1f3delta)820 mergescript(int i, int f1f3delta)
821 {
822 struct range r, *new, *old;
823 int n;
824
825 r.from = 1;
826 r.to = 1;
827
828 for (n = 1; n <= i; n++) {
829 new = &de[n].new;
830 old = &de[n].old;
831
832 /*
833 * Print any lines leading up to here. If we are merging don't
834 * print deleted ranges.
835 */
836 if (de[n].type == DIFF_TYPE1)
837 r.to = old->to;
838 else if (de[n].type == DIFF_TYPE2)
839 r.to = new->from + de_delta[n];
840 else
841 r.to = old->from;
842
843 printrange(fp[0], &r);
844 switch (de[n].type) {
845 case DIFF_TYPE1:
846 /* Content included in "between" printing from fp[0] */
847 break;
848 case DIFF_TYPE2:
849 printf("%s %s\n", oldmark, f2mark);
850 printrange(fp[1], old);
851 printf("%s\n", divider);
852 printrange(fp[2], new);
853 printf("%s %s\n", newmark, f3mark);
854 break;
855 case DIFF_TYPE3:
856 if (!oflag || !overlap[n]) {
857 printrange(fp[2], new);
858 } else {
859
860 printf("%s %s\n", oldmark, f1mark);
861 printrange(fp[0], old);
862
863 if (eflag != EFLAG_OVERLAP) {
864 printf("%s %s\n", orgmark, f2mark);
865 if (old->from == old->to) {
866 struct range or;
867 or.from = old->from - 1;
868 or.to = new->to;
869 printrange(fp[1], &or);
870 } else {
871 printrange(fp[1], old);
872 }
873 }
874
875 printf("%s\n", divider);
876
877 printrange(fp[2], new);
878 printf("%s %s\n", newmark, f3mark);
879 }
880 break;
881 default:
882 __assert_unreachable();
883 }
884
885 if (de[n].type == DIFF_TYPE2)
886 r.from = new->to + de_delta[n];
887 else
888 r.from = old->to;
889 }
890
891 /*
892 * Print from the final range to the end of 'myfile'. Any deletions or
893 * additions to this file should have been handled by now.
894 */
895 r.from -= f1f3delta;
896 r.to = INT_MAX;
897 printrange(fp[2], &r);
898 exit(overlapcnt > 0);
899 }
900
901 static void
increase(void)902 increase(void)
903 {
904 struct diff *p;
905 char *q;
906 int *s;
907 size_t newsz, incr;
908
909 /* are the memset(3) calls needed? */
910 newsz = szchanges == 0 ? 64 : 2 * szchanges;
911 incr = newsz - szchanges;
912
913 p = reallocarray(d13, newsz, sizeof(*p));
914 if (p == NULL)
915 err(2, NULL);
916 memset(p + szchanges, 0, incr * sizeof(*p));
917 d13 = p;
918 p = reallocarray(d23, newsz, sizeof(*p));
919 if (p == NULL)
920 err(2, NULL);
921 memset(p + szchanges, 0, incr * sizeof(*p));
922 d23 = p;
923 p = reallocarray(de, newsz, sizeof(*p));
924 if (p == NULL)
925 err(2, NULL);
926 memset(p + szchanges, 0, incr * sizeof(*p));
927 de = p;
928 q = reallocarray(overlap, newsz, 1);
929 if (q == NULL)
930 err(2, NULL);
931 memset(q + szchanges, 0, incr * 1);
932 overlap = q;
933 s = reallocarray(de_delta, newsz, sizeof(*s));
934 if (s == NULL)
935 err(2, NULL);
936 memset(s + szchanges, 0, incr * sizeof(*s));
937 de_delta = s;
938 szchanges = newsz;
939 }
940
941 static void
wait_and_check(int pd)942 wait_and_check(int pd)
943 {
944 int status;
945
946 while (pdwait(pd, &status, WEXITED, NULL, NULL) == -1) {
947 if (errno != EINTR)
948 err(2, "pdwait");
949 }
950 close(pd);
951
952 if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
953 errx(2, "diff exited abnormally");
954 if (WIFSIGNALED(status))
955 errx(2, "diff killed by signal %d", WTERMSIG(status));
956 }
957
958 int
main(int argc,char ** argv)959 main(int argc, char **argv)
960 {
961 int ch, nblabels, m, n;
962 char *labels[] = { NULL, NULL, NULL };
963 const char *diffprog = DIFF_PATH;
964 char *file1, *file2, *file3;
965 char *diffargv[7];
966 int diffargc = 0;
967 int fd13[2], fd23[2];
968 int pd13, pd23;
969 cap_rights_t rights_ro;
970
971 nblabels = 0;
972 eflag = EFLAG_NONE;
973 oflag = 0;
974 diffargv[diffargc++] = __DECONST(char *, diffprog);
975 while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
976 switch (ch) {
977 case '3':
978 eflag = EFLAG_NOOVERLAP;
979 break;
980 case 'a':
981 diffargv[diffargc++] = __DECONST(char *, "-a");
982 break;
983 case 'A':
984 Aflag = 1;
985 break;
986 case 'e':
987 eflag = EFLAG_UNMERGED;
988 break;
989 case 'E':
990 eflag = EFLAG_OVERLAP;
991 oflag = 1;
992 break;
993 case 'i':
994 iflag = 1;
995 break;
996 case 'L':
997 oflag = 1;
998 if (nblabels >= 3)
999 errx(2, "too many file label options");
1000 labels[nblabels++] = optarg;
1001 break;
1002 case 'm':
1003 Aflag = 1;
1004 oflag = 1;
1005 mflag = 1;
1006 break;
1007 case 'T':
1008 Tflag = 1;
1009 break;
1010 case 'x':
1011 eflag = EFLAG_OVERLAP;
1012 break;
1013 case 'X':
1014 oflag = 1;
1015 eflag = EFLAG_OVERLAP;
1016 break;
1017 case DIFFPROG_OPT:
1018 diffargv[0] = optarg;
1019 break;
1020 case STRIPCR_OPT:
1021 strip_cr = 1;
1022 diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
1023 break;
1024 case HELP_OPT:
1025 usage();
1026 exit(0);
1027 case VERSION_OPT:
1028 printf("%s\n", diff3_version);
1029 exit(0);
1030 }
1031 }
1032 argc -= optind;
1033 argv += optind;
1034
1035 if (Aflag) {
1036 if (eflag == EFLAG_NONE)
1037 eflag = EFLAG_UNMERGED;
1038 oflag = 1;
1039 }
1040
1041 if (argc != 3) {
1042 usage();
1043 exit(2);
1044 }
1045
1046 if (caph_limit_stdio() == -1)
1047 err(2, "unable to limit stdio");
1048
1049 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
1050
1051 /* TODO stdio */
1052 file1 = argv[0];
1053 file2 = argv[1];
1054 file3 = argv[2];
1055
1056 if (oflag) {
1057 asprintf(&f1mark, "%s",
1058 labels[0] != NULL ? labels[0] : file1);
1059 if (f1mark == NULL)
1060 err(2, "asprintf");
1061 asprintf(&f2mark, "%s",
1062 labels[1] != NULL ? labels[1] : file2);
1063 if (f2mark == NULL)
1064 err(2, "asprintf");
1065 asprintf(&f3mark, "%s",
1066 labels[2] != NULL ? labels[2] : file3);
1067 if (f3mark == NULL)
1068 err(2, "asprintf");
1069 }
1070 fp[0] = fopen(file1, "r");
1071 if (fp[0] == NULL)
1072 err(2, "Can't open %s", file1);
1073 if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
1074 err(2, "unable to limit rights on: %s", file1);
1075
1076 fp[1] = fopen(file2, "r");
1077 if (fp[1] == NULL)
1078 err(2, "Can't open %s", file2);
1079 if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
1080 err(2, "unable to limit rights on: %s", file2);
1081
1082 fp[2] = fopen(file3, "r");
1083 if (fp[2] == NULL)
1084 err(2, "Can't open %s", file3);
1085 if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
1086 err(2, "unable to limit rights on: %s", file3);
1087
1088 if (pipe(fd13))
1089 err(2, "pipe");
1090 if (pipe(fd23))
1091 err(2, "pipe");
1092
1093
1094 diffargv[diffargc] = file1;
1095 diffargv[diffargc + 1] = file3;
1096 diffargv[diffargc + 2] = NULL;
1097 pd13 = diffexec(diffargv, fd13);
1098
1099 diffargv[diffargc] = file2;
1100 pd23 = diffexec(diffargv, fd23);
1101
1102 caph_cache_catpages();
1103 if (caph_enter() < 0)
1104 err(2, "unable to enter capability mode");
1105
1106 /* parse diffs */
1107 increase();
1108 m = readin(fd13[0], &d13);
1109 n = readin(fd23[0], &d23);
1110
1111 wait_and_check(pd13);
1112 wait_and_check(pd23);
1113
1114 merge(m, n);
1115
1116 exit(0);
1117 }
1118