1 /* $OpenBSD: diff3prog.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $ */
4 * Copyright (C) Caldera International Inc. 2001-2002.
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8 * modification, are permitted provided that the following conditions
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14 * documentation and/or other materials provided with the distribution.
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16 * must display the following acknowledgement:
17 * This product includes software developed or owned by Caldera
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21 * this software without specific prior written permission.
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37 * Copyright (c) 1991, 1993
38 * The Regents of the University of California. All rights reserved.
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
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.
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49 * may be used to endorse or promote products derived from this software
50 * without specific prior written permission.
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
64 * @(#)diff3.c 8.1 (Berkeley) 6/6/93
69 static char sccsid[] = "@(#)diff3.c 8.1 (Berkeley) 6/6/93";
72 #include <sys/cdefs.h>
73 __FBSDID("$FreeBSD$");
75 #include <sys/capsicum.h>
76 #include <sys/procdesc.h>
77 #include <sys/types.h>
78 #include <sys/event.h>
81 #include <capsicum_helpers.h>
94 * "from" is first in range of changed lines; "to" is last+1
95 * from=to=line after point of insertion for added lines.
110 /* Ranges as lines */
116 #define EFLAG_OVERLAP 1
117 #define EFLAG_NOOVERLAP 2
118 #define EFLAG_UNMERGED 3
120 static size_t szchanges;
122 static struct diff *d13;
123 static struct diff *d23;
125 * "de" is used to gather editing scripts. These are later spewed out in
126 * reverse order. Its first element must be all zero, the "old" and "new"
127 * components of "de" contain line positions. Array overlap indicates which
128 * sections in "de" correspond to lines that are different in all three files.
130 static struct diff *de;
131 static char *overlap;
132 static int overlapcnt;
134 static int cline[3]; /* # of the last-read line in each file (0-2) */
136 * The latest known correspondence between line numbers of the 3 files
137 * is stored in last[1-3];
140 static int Aflag, eflag, iflag, mflag, Tflag;
141 static int oflag; /* indicates whether to mark overlaps (-E or -X) */
143 static char *f1mark, *f2mark, *f3mark;
144 static const char *oldmark = "<<<<<<<";
145 static const char *orgmark = "|||||||";
146 static const char *newmark = ">>>>>>>";
147 static const char *divider = "=======";
149 static bool duplicate(struct range *, struct range *);
150 static int edit(struct diff *, bool, int, int);
151 static char *getchange(FILE *);
152 static char *get_line(FILE *, size_t *);
153 static int readin(int fd, struct diff **);
154 static int skip(int, int, const char *);
155 static void change(int, struct range *, bool);
156 static void keep(int, struct range *);
157 static void merge(int, int);
158 static void prange(struct range *, bool);
159 static void repos(int);
160 static void edscript(int) __dead2;
161 static void Ascript(int) __dead2;
162 static void mergescript(int) __dead2;
163 static void increase(void);
164 static void usage(void);
165 static void printrange(FILE *, struct range *);
167 static const char diff3_version[] = "FreeBSD diff3 20220517";
176 #define DIFF_PATH "/usr/bin/diff"
178 #define OPTIONS "3aAeEiL:mTxX"
179 static struct option longopts[] = {
180 { "ed", no_argument, NULL, 'e' },
181 { "show-overlap", no_argument, NULL, 'E' },
182 { "overlap-only", no_argument, NULL, 'x' },
183 { "initial-tab", no_argument, NULL, 'T' },
184 { "text", no_argument, NULL, 'a' },
185 { "strip-trailing-cr", no_argument, NULL, STRIPCR_OPT },
186 { "show-all", no_argument, NULL, 'A' },
187 { "easy-only", no_argument, NULL, '3' },
188 { "merge", no_argument, NULL, 'm' },
189 { "label", required_argument, NULL, 'L' },
190 { "diff-program", required_argument, NULL, DIFFPROG_OPT },
191 { "help", no_argument, NULL, HELP_OPT},
192 { "version", no_argument, NULL, VERSION_OPT}
198 fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
199 "[-L label3] file1 file2 file3\n");
203 readin(int fd, struct diff **dd)
213 for (i = 0; (p = getchange(f)); i++) {
215 (*dd)[i].line = strdup(p);
218 if (i >= szchanges - 1)
220 a = b = (int)strtoimax(p, &p, 10);
223 b = (int)strtoimax(p, &p, 10);
226 c = d = (int)strtoimax(p, &p, 10);
229 d = (int)strtoimax(p, &p, 10);
237 (*dd)[i].old.from = a;
239 (*dd)[i].new.from = c;
243 (*dd)[i].old.from = (*dd)[i - 1].old.to;
244 (*dd)[i].new.from = (*dd)[i - 1].new.to;
251 diffexec(const char *diffprog, char **diffargv, int fd[])
255 switch (pdfork(&pd, PD_CLOEXEC)) {
258 if (dup2(fd[1], STDOUT_FILENO) == -1)
259 err(2, "child could not duplicate descriptor");
261 execvp(diffprog, diffargv);
262 err(2, "could not execute diff: %s", diffprog);
265 err(2, "could not fork");
277 while ((line = get_line(b, NULL))) {
278 if (isdigit((unsigned char)line[0]))
286 get_line(FILE *b, size_t *n)
289 static char *buf = NULL;
290 static size_t bufsize = 0;
292 if ((len = getline(&buf, &bufsize, b)) < 0)
295 if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
308 merge(int m1, int m2)
310 struct diff *d1, *d2, *d3;
318 while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
319 /* first file is different from the others */
320 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
321 /* stuff peculiar to 1st file */
322 if (eflag == EFLAG_NONE) {
324 change(1, &d1->old, false);
326 change(3, &d1->new, false);
331 /* second file is different from others */
332 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
333 if (eflag == EFLAG_NONE) {
336 change(3, &d2->new, false);
337 change(2, &d2->old, false);
338 } else if (Aflag || mflag) {
339 // XXX-THJ: What does it mean for the second file to differ?
340 j = edit(d2, dup, j, DIFF_TYPE2);
346 * Merge overlapping changes in first file
347 * this happens after extension (see below).
349 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
350 d1[1].old.from = d1->old.from;
351 d1[1].new.from = d1->new.from;
356 /* merge overlapping changes in second */
357 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
358 d2[1].old.from = d2->old.from;
359 d2[1].new.from = d2->new.from;
363 /* stuff peculiar to third file or different in all */
364 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
365 dup = duplicate(&d1->old, &d2->old);
367 * dup = 0 means all files differ
368 * dup = 1 means files 1 and 2 identical
370 if (eflag == EFLAG_NONE) {
371 printf("====%s\n", dup ? "3" : "");
372 change(1, &d1->old, dup);
373 change(2, &d2->old, false);
374 d3 = d1->old.to > d1->old.from ? d1 : d2;
375 change(3, &d3->new, false);
377 j = edit(d1, dup, j, DIFF_TYPE3);
385 * Overlapping changes from file 1 and 2; extend changes
386 * appropriately to make them coincide.
388 if (d1->new.from < d2->new.from) {
389 d2->old.from -= d2->new.from - d1->new.from;
390 d2->new.from = d1->new.from;
391 } else if (d2->new.from < d1->new.from) {
392 d1->old.from -= d1->new.from - d2->new.from;
393 d1->new.from = d2->new.from;
395 if (d1->new.to > d2->new.to) {
396 d2->old.to += d1->new.to - d2->new.to;
397 d2->new.to = d1->new.to;
398 } else if (d2->new.to > d1->new.to) {
399 d1->old.to += d2->new.to - d1->new.to;
400 d1->new.to = d2->new.to;
413 * The range of lines rold.from thru rold.to in file i is to be changed.
414 * It is to be printed only if it does not duplicate something to be
418 change(int i, struct range *rold, bool dup)
427 skip(i, rold->from, NULL);
428 skip(i, rold->to, " ");
432 * Print the range of line numbers, rold.from thru rold.to, as n1,n2 or
436 prange(struct range *rold, bool delete)
439 if (rold->to <= rold->from)
440 printf("%da\n", rold->from - 1);
442 printf("%d", rold->from);
443 if (rold->to > rold->from + 1)
444 printf(",%d", rold->to - 1);
453 * No difference was reported by diff between file 1 (or 2) and file 3,
454 * and an artificial dummy difference (trange) must be ginned up to
455 * correspond to the change reported in the other file.
458 keep(int i, struct range *rnew)
463 delta = last[3] - last[i];
464 trange.from = rnew->from - delta;
465 trange.to = rnew->to - delta;
466 change(i, &trange, true);
470 * skip to just before line number from in file "i". If "pr" is non-NULL,
471 * print all skipped stuff with string pr as a prefix.
474 skip(int i, int from, const char *pr)
479 for (n = 0; cline[i] < from - 1; n += j) {
480 if ((line = get_line(fp[i], &j)) == NULL)
481 errx(EXIT_FAILURE, "logic error");
483 printf("%s%s", Tflag == 1 ? "\t" : pr, line);
490 * Return 1 or 0 according as the old range (in file 1) contains exactly
491 * the same data as the new range (in file 2).
494 duplicate(struct range *r1, struct range *r2)
500 if (r1->to-r1->from != r2->to-r2->from)
502 skip(0, r1->from, NULL);
503 skip(1, r2->from, NULL);
505 for (nline = 0; nline < r1->to - r1->from; nline++) {
509 if (c == -1 && d == -1)
511 if (c == -1 || d == -1)
512 errx(EXIT_FAILURE, "logic error");
529 for (i = 0; i < 2; i++)
530 (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
534 * collect an editing script for later regurgitation
537 edit(struct diff *diff, bool dup, int j, int difftype)
539 if (!(eflag == EFLAG_UNMERGED ||
540 (!dup && eflag == EFLAG_OVERLAP ) ||
541 (dup && eflag == EFLAG_NOOVERLAP))) {
549 de[j].type = difftype;
551 de[j].line = strdup(diff->line);
554 de[j].old.from = diff->old.from;
555 de[j].old.to = diff->old.to;
556 de[j].new.from = diff->new.from;
557 de[j].new.to = diff->new.to;
562 printrange(FILE *p, struct range *r)
569 /* We haven't been asked to print anything */
570 if (r->from == r->to)
574 errx(EXIT_FAILURE, "invalid print range");
577 * XXX-THJ: We read through all of the file for each range printed.
578 * This duplicates work and will probably impact performance on large
579 * files with lots of ranges.
581 fseek(p, 0L, SEEK_SET);
582 while ((rlen = getline(&line, &len, p)) > 0) {
596 struct range *new, *old;
602 delete = (new->from == new->to);
603 if (!oflag || !overlap[n]) {
606 printf("%da\n", old->to - 1);
607 printf("%s\n", divider);
609 printrange(fp[2], new);
610 if (!oflag || !overlap[n]) {
614 printf("%s %s\n.\n", newmark, f3mark);
615 printf("%da\n%s %s\n.\n", old->from - 1,
622 exit(eflag == EFLAG_NONE ? overlapcnt : 0);
626 * Output an edit script to turn mine into yours, when there is a conflict
627 * between the 3 files bracket the changes. Regurgitate the diffs in reverse
628 * order to allow the ed script to track down where the lines are as changes
638 struct range *new, *old;
643 deletenew = (new->from == new->to);
644 deleteold = (old->from == old->to);
646 if (de[n].type == DIFF_TYPE2) {
647 if (!oflag || !overlap[n]) {
648 prange(old, deletenew);
649 printrange(fp[2], new);
656 printf("%da\n", startmark);
657 printf("%s %s\n", newmark, f3mark);
661 printf("%da\n", startmark -
662 (new->to - new->from));
663 printf("%s %s\n", oldmark, f2mark);
665 printrange(fp[1], old);
666 printf("%s\n.\n", divider);
669 } else if (de[n].type == DIFF_TYPE3) {
670 startmark = old->to - 1;
672 if (!oflag || !overlap[n]) {
673 prange(old, deletenew);
674 printrange(fp[2], new);
676 printf("%da\n", startmark);
677 printf("%s %s\n", orgmark, f2mark);
681 r.from = old->from-1;
683 printrange(fp[1], &r);
685 printrange(fp[1], old);
687 printf("%s\n", divider);
688 printrange(fp[2], new);
691 if (!oflag || !overlap[n]) {
695 printf("%s %s\n.\n", newmark, f3mark);
698 * Go to the start of the conflict in original
699 * file and append lines
701 printf("%da\n%s %s\n.\n",
702 startmark - (old->to - old->from),
710 exit(overlapcnt > 0);
714 * Output the merged file directly (don't generate an ed script). When
715 * regurgitating diffs we need to walk forward through the file and print any
721 struct range r, *new, *old;
727 for (n = 1; n < i+1; n++) {
731 /* print any lines leading up to here */
733 printrange(fp[0], &r);
735 if (de[n].type == DIFF_TYPE2) {
736 printf("%s %s\n", oldmark, f2mark);
737 printrange(fp[1], old);
738 printf("%s\n", divider);
739 printrange(fp[2], new);
740 printf("%s %s\n", newmark, f3mark);
741 } else if (de[n].type == DIFF_TYPE3) {
742 if (!oflag || !overlap[n]) {
743 printrange(fp[2], new);
746 printf("%s %s\n", oldmark, f1mark);
747 printrange(fp[0], old);
749 printf("%s %s\n", orgmark, f2mark);
750 if (old->from == old->to) {
752 or.from = old->from - 1;
754 printrange(fp[1], &or);
756 printrange(fp[1], old);
758 printf("%s\n", divider);
760 printrange(fp[2], new);
761 printf("%s %s\n", newmark, f3mark);
765 if (old->from == old->to)
771 * Print from the final range to the end of 'myfile'. Any deletions or
772 * additions to this file should have been handled by now.
774 * If the ranges are the same we need to rewind a line.
775 * If the new range is 0 length (from == to), we need to use the old
780 if ((old->from == new->from) &&
781 (old->to == new->to))
783 else if (new->from == new->to)
787 * If the range is a 3 way merge then we need to skip a line in the
790 if (de[n-1].type == DIFF_TYPE3)
794 printrange(fp[0], &r);
795 exit(overlapcnt > 0);
805 /* are the memset(3) calls needed? */
806 newsz = szchanges == 0 ? 64 : 2 * szchanges;
807 incr = newsz - szchanges;
809 p = reallocarray(d13, newsz, sizeof(struct diff));
812 memset(p + szchanges, 0, incr * sizeof(struct diff));
814 p = reallocarray(d23, newsz, sizeof(struct diff));
817 memset(p + szchanges, 0, incr * sizeof(struct diff));
819 p = reallocarray(de, newsz, sizeof(struct diff));
822 memset(p + szchanges, 0, incr * sizeof(struct diff));
824 q = reallocarray(overlap, newsz, sizeof(char));
827 memset(q + szchanges, 0, incr * sizeof(char));
834 main(int argc, char **argv)
836 int ch, nblabels, status, m, n, kq, nke, nleft, i;
837 char *labels[] = { NULL, NULL, NULL };
838 const char *diffprog = DIFF_PATH;
839 char *file1, *file2, *file3;
842 int fd13[2], fd23[2];
844 cap_rights_t rights_ro;
850 diffargv[diffargc++] = __DECONST(char *, diffprog);
851 while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
854 eflag = EFLAG_NOOVERLAP;
857 diffargv[diffargc++] = __DECONST(char *, "-a");
863 eflag = EFLAG_UNMERGED;
866 eflag = EFLAG_UNMERGED;
875 errx(2, "too many file label options");
876 labels[nblabels++] = optarg;
887 eflag = EFLAG_OVERLAP;
891 eflag = EFLAG_OVERLAP;
898 diffargv[diffargc++] = __DECONST(char *, "--strip-trailing-cr");
904 printf("%s\n", diff3_version);
912 eflag = EFLAG_UNMERGED;
921 if (caph_limit_stdio() == -1)
922 err(2, "unable to limit stdio");
924 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
930 e = malloc(2 * sizeof(struct kevent));
940 asprintf(&f1mark, "%s",
941 labels[0] != NULL ? labels[0] : file1);
944 asprintf(&f2mark, "%s",
945 labels[1] != NULL ? labels[1] : file2);
948 asprintf(&f3mark, "%s",
949 labels[2] != NULL ? labels[2] : file3);
953 fp[0] = fopen(file1, "r");
955 err(2, "Can't open %s", file1);
956 if (caph_rights_limit(fileno(fp[0]), &rights_ro) < 0)
957 err(2, "unable to limit rights on: %s", file1);
959 fp[1] = fopen(file2, "r");
961 err(2, "Can't open %s", file2);
962 if (caph_rights_limit(fileno(fp[1]), &rights_ro) < 0)
963 err(2, "unable to limit rights on: %s", file2);
965 fp[2] = fopen(file3, "r");
967 err(2, "Can't open %s", file3);
968 if (caph_rights_limit(fileno(fp[2]), &rights_ro) < 0)
969 err(2, "unable to limit rights on: %s", file3);
976 diffargv[diffargc] = file1;
977 diffargv[diffargc + 1] = file3;
978 diffargv[diffargc + 2] = NULL;
981 pd13 = diffexec(diffprog, diffargv, fd13);
982 EV_SET(e + nleft , pd13, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
983 if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
987 diffargv[diffargc] = file2;
988 pd23 = diffexec(diffprog, diffargv, fd23);
989 EV_SET(e + nleft , pd23, EVFILT_PROCDESC, EV_ADD, NOTE_EXIT, 0, NULL);
990 if (kevent(kq, e + nleft, 1, NULL, 0, NULL) == -1)
994 caph_cache_catpages();
995 if (caph_enter() < 0)
996 err(2, "unable to enter capability mode");
1000 m = readin(fd13[0], &d13);
1001 n = readin(fd23[0], &d23);
1003 /* waitpid cooked over pdforks */
1005 nke = kevent(kq, NULL, 0, e, nleft, NULL);
1008 for (i = 0; i < nke; i++) {
1010 if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
1011 errx(2, "diff exited abnormally");
1012 else if (WIFSIGNALED(status))
1013 errx(2, "diff killed by signal %d",
1020 return (EXIT_SUCCESS);