1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <unistd.h>
32 #include <limits.h>
33 #include <sys/param.h>
34 #include <errno.h>
35 #
36
37 /*
38 * diff3 - 3-way differential file comparison
39 */
40
41 /*
42 * diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
43 *
44 * d13 = diff report on f1 vs f3
45 * d23 = diff report on f2 vs f3
46 * f1, f2, f3 the 3 files
47 * if changes in f1 overlap with changes in f3, m1 and m3 are used
48 * to mark the overlaps; otherwise, the file names f1 and f3 are used
49 * (only for options E and X).
50 */
51
52 struct range {int from, to; };
53 /*
54 * from is first in range of changed lines
55 * to is last+1
56 * from = to = line after point of insertion
57 * for added lines
58 */
59 struct diff {struct range old, new; };
60
61 #define NC 4096
62 /*
63 * de is used to gather editing scripts,
64 * that are later spewed out in reverse order.
65 * its first element must be all zero
66 * the "new" component of de contains line positions
67 * or byte positions depending on when you look(!?)
68 */
69 static struct diff d13[NC];
70 static struct diff d23[NC];
71
72 /*
73 * array overlap indicates which sections in de correspond to
74 * lines that are different in all three files.
75 */
76
77 static struct diff de[NC];
78 static char overlap[NC];
79 static int overlapcnt = 0;
80
81 static char line[LINE_MAX+1];
82 static FILE *fp[3];
83 /*
84 * the number of the last-read line in each file
85 * is kept in cline[0-2]
86 */
87 static int cline[3];
88 /*
89 * the latest known correspondence between line
90 * numbers of the 3 files is stored in last[1-3]
91 */
92 static int last[4];
93 static int eflag;
94 static int oflag; /* indicates whether to mark overlaps (-E or -X) */
95 static int debug = 0;
96 /* markers for -E and -X: */
97 static char f1mark[8+MAXPATHLEN], f3mark[8+MAXPATHLEN];
98 /* Need space for "<<<<<<< " or ">>>>>>> " plus filename */
99 static int save_err; /* saves errno */
100
101 static int readin(char *name, struct diff *dd);
102 static int number(char **lc);
103 static int digit(int c);
104 static int getchange(FILE *b);
105 static int getaline(FILE *b);
106 static void merge(int m1, int m2);
107 static void separate(char *s);
108 static void change(int i, struct range *rold, int dup);
109 static void prange(struct range *rold);
110 static void keep(int i, struct range *rnew);
111 static int skip(int i, int from, char *pr);
112 static int duplicate(struct range *r1, struct range *r2);
113 static void repos(int nchar);
114 static void trouble();
115 static int edit(struct diff *diff, int dup, int j);
116 static void edscript(int n);
117 static void usage();
118
119 int
main(int argc,char ** argv)120 main(int argc, char **argv)
121 {
122 int i, m, n;
123 eflag = 0;
124 oflag = 0;
125 if ((argc > 1) && (*argv[1] == '-')) {
126 switch (argv[1][1]) {
127 case 'e':
128 eflag = 3;
129 break;
130 case '3':
131 eflag = 2;
132 break;
133 case 'x':
134 eflag = 1;
135 break;
136 case 'E':
137 eflag = 3;
138 oflag = 1;
139 break;
140 case 'X':
141 oflag = eflag = 1;
142 break;
143 default:
144 usage();
145 break;
146 }
147 argv++;
148 argc--;
149 }
150 if (argc < 6)
151 usage();
152 if (oflag) {
153 (void) snprintf(f1mark, sizeof (f1mark), "<<<<<<< %s",
154 argc >= 7 ? argv[6] : argv[3]);
155 (void) snprintf(f3mark, sizeof (f3mark), ">>>>>>> %s",
156 argc >= 8 ? argv[7] : argv[5]);
157 }
158
159 m = readin(argv[1], d13);
160 n = readin(argv[2], d23);
161 for (i = 0; i <= 2; i++)
162 if ((fp[i] = fopen(argv[i+3], "r")) == NULL) {
163 save_err = errno;
164 (void) fprintf(stderr, "diff3: can't open %s: ",
165 argv[i+3]);
166 errno = save_err;
167 perror("");
168 exit(1);
169 }
170 merge(m, n);
171 return (0);
172 }
173
174 /*
175 * pick up the line numbers of all changes from
176 * one change file
177 * (this puts the numbers in a vector, which is not
178 * strictly necessary, since the vector is processed
179 * in one sequential pass. The vector could be optimized
180 * out of existence)
181 */
182
183 static int
readin(char * name,struct diff * dd)184 readin(char *name, struct diff *dd)
185 {
186 int i;
187 int a, b, c, d;
188 char kind;
189 char *p;
190 if ((fp[0] = fopen(name, "r")) == NULL) {
191 save_err = errno;
192 (void) fprintf(stderr, "diff3: can't open %s: ", name);
193 errno = save_err;
194 perror("");
195 exit(1);
196 }
197 for (i = 0; getchange(fp[0]); i++) {
198 if (i >= NC) {
199 (void) fprintf(stderr, "diff3: too many changes\n");
200 exit(0);
201 }
202 p = line;
203 a = b = number(&p);
204 if (*p == ',') {
205 p++;
206 b = number(&p);
207 }
208 kind = *p++;
209 c = d = number(&p);
210 if (*p == ',') {
211 p++;
212 d = number(&p);
213 }
214 if (kind == 'a')
215 a++;
216 if (kind == 'd')
217 c++;
218 b++;
219 d++;
220 dd[i].old.from = a;
221 dd[i].old.to = b;
222 dd[i].new.from = c;
223 dd[i].new.to = d;
224 }
225 dd[i].old.from = dd[i-1].old.to;
226 dd[i].new.from = dd[i-1].new.to;
227 (void) fclose(fp[0]);
228 return (i);
229 }
230
231 static int
number(char ** lc)232 number(char **lc)
233 {
234 int nn;
235 nn = 0;
236 while (digit(**lc))
237 nn = nn*10 + *(*lc)++ - '0';
238 return (nn);
239 }
240
241 static int
digit(int c)242 digit(int c)
243 {
244 return (c >= '0' && c <= '9');
245 }
246
247 static int
getchange(FILE * b)248 getchange(FILE *b)
249 {
250 while (getaline(b))
251 if (digit(line[0]))
252 return (1);
253 return (0);
254 }
255
256 static int
getaline(FILE * b)257 getaline(FILE *b)
258 {
259 int i, c;
260 for (i = 0; i < sizeof (line)-1; i++) {
261 c = getc(b);
262 if (c == EOF) {
263 line[i] = 0;
264 return (i);
265 }
266 line[i] = c;
267 if (c == '\n') {
268 line[++i] = 0;
269 return (i);
270 }
271 }
272 return (0);
273 }
274
275 static void
merge(int m1,int m2)276 merge(int m1, int m2)
277 {
278 struct diff *d1, *d2, *d3;
279 int dup;
280 int j;
281 int t1, t2;
282 d1 = d13;
283 d2 = d23;
284 j = 0;
285 for (; (t1 = d1 < d13+m1) | (t2 = d2 < d23+m2); ) {
286 if (debug) {
287 (void) printf("%d,%d=%d,%d %d,%d=%d,%d\n",
288 d1->old.from, d1->old.to,
289 d1->new.from, d1->new.to,
290 d2->old.from, d2->old.to,
291 d2->new.from, d2->new.to);
292 }
293
294 /* first file is different from others */
295 if (!t2 || t1 && d1->new.to < d2->new.from) {
296 /* stuff peculiar to 1st file */
297 if (eflag == 0) {
298 separate("1");
299 change(1, &d1->old, 0);
300 keep(2, &d1->new);
301 change(3, &d1->new, 0);
302 }
303 d1++;
304 continue;
305 }
306
307 /* second file is different from others */
308 if (!t1 || t2 && d2->new.to < d1->new.from) {
309 if (eflag == 0) {
310 separate("2");
311 keep(1, &d2->new);
312 change(2, &d2->old, 0);
313 change(3, &d2->new, 0);
314 }
315 d2++;
316 continue;
317 }
318 /*
319 * merge overlapping changes in first file
320 * this happens after extension see below
321 */
322 if (d1+1 < d13+m1 && d1->new.to >= d1[1].new.from) {
323 d1[1].old.from = d1->old.from;
324 d1[1].new.from = d1->new.from;
325 d1++;
326 continue;
327 }
328
329 /* merge overlapping changes in second */
330 if (d2+1 < d23+m2 && d2->new.to >= d2[1].new.from) {
331 d2[1].old.from = d2->old.from;
332 d2[1].new.from = d2->new.from;
333 d2++;
334 continue;
335 }
336
337 /* stuff peculiar to third file or different in all */
338 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
339 dup = duplicate(&d1->old, &d2->old);
340 /*
341 * dup = 0 means all files differ
342 * dup = 1 meands files 1&2 identical
343 */
344 if (eflag == 0) {
345 separate(dup?"3":"");
346 change(1, &d1->old, dup);
347 change(2, &d2->old, 0);
348 d3 = d1->old.to > d1->old.from ? d1 : d2;
349 change(3, &d3->new, 0);
350 } else
351 j = edit(d1, dup, j);
352 d1++;
353 d2++;
354 continue;
355 }
356 /*
357 * overlapping changes from file1 & 2
358 * extend changes appropriately to
359 * make them coincide
360 */
361 if (d1->new.from < d2->new.from) {
362 d2->old.from -= d2->new.from-d1->new.from;
363 d2->new.from = d1->new.from;
364 } else if (d2->new.from < d1->new.from) {
365 d1->old.from -= d1->new.from-d2->new.from;
366 d1->new.from = d2->new.from;
367 }
368
369 if (d1->new.to > d2->new.to) {
370 d2->old.to += d1->new.to - d2->new.to;
371 d2->new.to = d1->new.to;
372 } else if (d2->new.to > d1->new.to) {
373 d1->old.to += d2->new.to - d1->new.to;
374 d1->new.to = d2->new.to;
375 }
376 }
377 if (eflag) {
378 edscript(j);
379 if (j)
380 (void) printf("w\nq\n");
381 }
382 }
383
384 static void
separate(char * s)385 separate(char *s)
386 {
387 (void) printf("====%s\n", s);
388 }
389
390 /*
391 * the range of ines rold.from thru rold.to in file i
392 * is to be changed. it is to be printed only if
393 * it does not duplicate something to be printed later
394 */
395 static void
change(int i,struct range * rold,int dup)396 change(int i, struct range *rold, int dup)
397 {
398 (void) printf("%d:", i);
399 last[i] = rold->to;
400 prange(rold);
401 if (dup)
402 return;
403 if (debug)
404 return;
405 i--;
406 (void) skip(i, rold->from, (char *)0);
407 (void) skip(i, rold->to, " ");
408 }
409
410 /*
411 * print the range of line numbers, rold.from thru rold.to
412 * as n1, n2 or n1
413 */
414 static void
prange(struct range * rold)415 prange(struct range *rold)
416 {
417 if (rold->to <= rold->from)
418 (void) printf("%da\n", rold->from-1);
419 else {
420 (void) printf("%d", rold->from);
421 if (rold->to > rold->from+1)
422 (void) printf(",%d", rold->to-1);
423 (void) printf("c\n");
424 }
425 }
426
427 /*
428 * no difference was reported by diff between file 1(or 2)
429 * and file 3, and an artificial dummy difference (trange)
430 * must be ginned up to correspond to the change reported
431 * in the other file
432 */
433 static void
keep(int i,struct range * rnew)434 keep(int i, struct range *rnew)
435 {
436 int delta;
437 struct range trange;
438 delta = last[3] - last[i];
439 trange.from = rnew->from - delta;
440 trange.to = rnew->to - delta;
441 change(i, &trange, 1);
442 }
443
444 /*
445 * skip to just befor line number from in file i
446 * if "pr" is nonzero, print all skipped stuff
447 * with string pr as a prefix
448 */
449 static int
skip(int i,int from,char * pr)450 skip(int i, int from, char *pr)
451 {
452 int j, n;
453 for (n = 0; cline[i] < from-1; n += j) {
454 if ((j = getaline(fp[i])) == 0)
455 trouble();
456 if (pr)
457 (void) printf("%s%s", pr, line);
458 cline[i]++;
459 }
460 return (n);
461 }
462
463 /*
464 * return 1 or 0 according as the old range
465 * (in file 1) contains exactly the same data
466 * as the new range (in file 2)
467 */
468 static int
duplicate(struct range * r1,struct range * r2)469 duplicate(struct range *r1, struct range *r2)
470 {
471 int c, d;
472 int nchar;
473 int nline;
474 if (r1->to-r1->from != r2->to-r2->from)
475 return (0);
476 (void) skip(0, r1->from, (char *)0);
477 (void) skip(1, r2->from, (char *)0);
478 nchar = 0;
479 for (nline = 0; nline < r1->to-r1->from; nline++) {
480 do {
481 c = getc(fp[0]);
482 d = getc(fp[1]);
483 if (c == -1 || d == -1)
484 trouble();
485 nchar++;
486 if (c != d) {
487 repos(nchar);
488 return (0);
489 }
490 } while (c != '\n');
491 }
492 repos(nchar);
493 return (1);
494 }
495
496 static void
repos(int nchar)497 repos(int nchar)
498 {
499 int i;
500 for (i = 0; i < 2; i++)
501 (void) fseek(fp[i], (long)-nchar, 1);
502 }
503
504 static void
trouble()505 trouble()
506 {
507 (void) fprintf(stderr, "diff3: logic error\n");
508 abort();
509 }
510
511 /*
512 * collect an editing script for later regurgitation
513 */
514 static int
edit(struct diff * diff,int dup,int j)515 edit(struct diff *diff, int dup, int j)
516 {
517 if (((dup+1)&eflag) == 0)
518 return (j);
519 j++;
520 overlap[j] = !dup;
521 if (!dup) overlapcnt++;
522 de[j].old.from = diff->old.from;
523 de[j].old.to = diff->old.to;
524 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, (char *)0);
525 de[j].new.to = de[j].new.from + skip(2, diff->new.to, (char *)0);
526 return (j);
527 }
528
529 /* regurgitate */
530 static void
edscript(int n)531 edscript(int n)
532 {
533 int j, k;
534 char block[BUFSIZ];
535
536 for (n = n; n > 0; n--) {
537 if (!oflag || !overlap[n])
538 prange(&de[n].old);
539 else
540 (void) printf("%da\n=======\n", de[n].old.to -1);
541 (void) fseek(fp[2], (long)de[n].new.from, 0);
542 for (k = de[n].new.to-de[n].new.from; k > 0; k -= j) {
543 j = k > BUFSIZ?BUFSIZ:k;
544 if (fread(block, 1, j, fp[2]) != j)
545 trouble();
546 (void) fwrite(block, 1, j, stdout);
547 }
548 if (!oflag || !overlap[n])
549 (void) printf(".\n");
550 else {
551 (void) printf("%s\n.\n", f3mark);
552 (void) printf("%da\n%s\n.\n", de[n].old.from-1, f1mark);
553 }
554 }
555 }
556
557 static void
usage()558 usage()
559 {
560 (void) fprintf(stderr,
561 "\tusage: diff3prog [-ex3EX] d13 d23 f1 f2 f3 [m1 m2]\n");
562 exit(1);
563 }
564