1 /* $OpenBSD: diff3prog.c,v 1.17 2015/10/09 01:37:07 deraadt 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 <err.h> 69 #include <stdio.h> 70 #include <stdlib.h> 71 #include <string.h> 72 #include <unistd.h> 73 74 /* diff3 - 3-way differential file comparison */ 75 76 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 77 * 78 * d13 = diff report on f1 vs f3 79 * d23 = diff report on f2 vs f3 80 * f1, f2, f3 the 3 files 81 * if changes in f1 overlap with changes in f3, m1 and m3 are used 82 * to mark the overlaps; otherwise, the file names f1 and f3 are used 83 * (only for options E and X). 84 */ 85 86 /* 87 * "from" is first in range of changed lines; "to" is last+1 88 * from=to=line after point of insertion for added lines. 89 */ 90 struct range { 91 int from; 92 int to; 93 }; 94 struct diff { 95 struct range old; 96 struct range new; 97 }; 98 99 size_t szchanges; 100 101 struct diff *d13; 102 struct diff *d23; 103 /* 104 * "de" is used to gather editing scripts. These are later spewed out in 105 * reverse order. Its first element must be all zero, the "new" component 106 * of "de" contains line positions or byte positions depending on when you 107 * look (!?). Array overlap indicates which sections in "de" correspond to 108 * lines that are different in all three files. 109 */ 110 struct diff *de; 111 char *overlap; 112 int overlapcnt; 113 FILE *fp[3]; 114 int cline[3]; /* # of the last-read line in each file (0-2) */ 115 /* 116 * the latest known correspondence between line numbers of the 3 files 117 * is stored in last[1-3]; 118 */ 119 int last[4]; 120 int eflag; 121 int oflag; /* indicates whether to mark overlaps (-E or -X)*/ 122 int debug = 0; 123 char f1mark[40], f3mark[40]; /* markers for -E and -X */ 124 125 int duplicate(struct range *, struct range *); 126 int edit(struct diff *, int, int); 127 char *getchange(FILE *); 128 char *get_line(FILE *, size_t *); 129 int number(char **); 130 int readin(char *, struct diff **); 131 int skip(int, int, char *); 132 void change(int, struct range *, int); 133 void keep(int, struct range *); 134 void merge(int, int); 135 void prange(struct range *); 136 void repos(int); 137 void separate(const char *); 138 __dead void edscript(int); 139 __dead void trouble(void); 140 void increase(void); 141 __dead void usage(void); 142 143 int 144 main(int argc, char **argv) 145 { 146 int ch, i, m, n; 147 148 if (pledge("stdio rpath", NULL) == -1) 149 err(1, "pledge"); 150 151 eflag = 0; 152 oflag = 0; 153 while ((ch = getopt(argc, argv, "EeXx3")) != -1) { 154 switch (ch) { 155 case 'E': 156 eflag = 3; 157 oflag = 1; 158 break; 159 case 'e': 160 eflag = 3; 161 break; 162 case 'X': 163 oflag = eflag = 1; 164 break; 165 case 'x': 166 eflag = 1; 167 break; 168 case '3': 169 eflag = 2; 170 break; 171 } 172 } 173 argc -= optind; 174 argv += optind; 175 /* XXX - argc usage seems wrong here */ 176 if (argc < 5) 177 usage(); 178 179 if (oflag) { 180 (void)snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", 181 argc >= 6 ? argv[5] : argv[2]); 182 (void)snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", 183 argc >= 7 ? argv[6] : argv[4]); 184 } 185 186 increase(); 187 m = readin(argv[0], &d13); 188 n = readin(argv[1], &d23); 189 for (i = 0; i <= 2; i++) { 190 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) 191 err(EXIT_FAILURE, "can't open %s", argv[i + 2]); 192 } 193 merge(m, n); 194 exit(EXIT_SUCCESS); 195 } 196 197 /* 198 * Pick up the line numbers of all changes from one change file. 199 * (This puts the numbers in a vector, which is not strictly necessary, 200 * since the vector is processed in one sequential pass. 201 * The vector could be optimized out of existence) 202 */ 203 int 204 readin(char *name, struct diff **dd) 205 { 206 int a, b, c, d, i; 207 char kind, *p; 208 209 fp[0] = fopen(name, "r"); 210 if (fp[0] == NULL) 211 err(EXIT_FAILURE, "can't open %s", name); 212 for (i=0; (p = getchange(fp[0])); i++) { 213 if (i >= szchanges - 1) 214 increase(); 215 a = b = number(&p); 216 if (*p == ',') { 217 p++; 218 b = number(&p); 219 } 220 kind = *p++; 221 c = d = number(&p); 222 if (*p==',') { 223 p++; 224 d = number(&p); 225 } 226 if (kind == 'a') 227 a++; 228 if (kind == 'd') 229 c++; 230 b++; 231 d++; 232 (*dd)[i].old.from = a; 233 (*dd)[i].old.to = b; 234 (*dd)[i].new.from = c; 235 (*dd)[i].new.to = d; 236 } 237 if (i) { 238 (*dd)[i].old.from = (*dd)[i-1].old.to; 239 (*dd)[i].new.from = (*dd)[i-1].new.to; 240 } 241 (void)fclose(fp[0]); 242 return (i); 243 } 244 245 int 246 number(char **lc) 247 { 248 int nn; 249 nn = 0; 250 while (isdigit((unsigned char)(**lc))) 251 nn = nn*10 + *(*lc)++ - '0'; 252 return (nn); 253 } 254 255 char * 256 getchange(FILE *b) 257 { 258 char *line; 259 260 while ((line = get_line(b, NULL))) { 261 if (isdigit((unsigned char)line[0])) 262 return (line); 263 } 264 return (NULL); 265 } 266 267 char * 268 get_line(FILE *b, size_t *n) 269 { 270 char *cp; 271 size_t len; 272 static char *buf; 273 static size_t bufsize; 274 275 if ((cp = fgetln(b, &len)) == NULL) 276 return (NULL); 277 278 if (cp[len - 1] != '\n') 279 len++; 280 if (len + 1 > bufsize) { 281 do { 282 bufsize += 1024; 283 } while (len + 1 > bufsize); 284 if ((buf = realloc(buf, bufsize)) == NULL) 285 err(EXIT_FAILURE, NULL); 286 } 287 memcpy(buf, cp, len - 1); 288 buf[len - 1] = '\n'; 289 buf[len] = '\0'; 290 if (n != NULL) 291 *n = len; 292 return (buf); 293 } 294 295 void 296 merge(int m1, int m2) 297 { 298 struct diff *d1, *d2, *d3; 299 int dup, j, t1, t2; 300 301 d1 = d13; 302 d2 = d23; 303 j = 0; 304 while ((t1 = (d1 < d13 + m1)) | (t2 = (d2 < d23 + m2))) { 305 if (debug) { 306 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 307 d1->old.from,d1->old.to, 308 d1->new.from,d1->new.to, 309 d2->old.from,d2->old.to, 310 d2->new.from,d2->new.to); 311 } 312 /* first file is different from others */ 313 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 314 /* stuff peculiar to 1st file */ 315 if (eflag==0) { 316 separate("1"); 317 change(1, &d1->old, 0); 318 keep(2, &d1->new); 319 change(3, &d1->new, 0); 320 } 321 d1++; 322 continue; 323 } 324 /* second file is different from others */ 325 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 326 if (eflag==0) { 327 separate("2"); 328 keep(1, &d2->new); 329 change(2, &d2->old, 0); 330 change(3, &d2->new, 0); 331 } 332 d2++; 333 continue; 334 } 335 /* 336 * Merge overlapping changes in first file 337 * this happens after extension (see below). 338 */ 339 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 340 d1[1].old.from = d1->old.from; 341 d1[1].new.from = d1->new.from; 342 d1++; 343 continue; 344 } 345 346 /* merge overlapping changes in second */ 347 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 348 d2[1].old.from = d2->old.from; 349 d2[1].new.from = d2->new.from; 350 d2++; 351 continue; 352 } 353 /* stuff peculiar to third file or different in all */ 354 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 355 dup = duplicate(&d1->old,&d2->old); 356 /* 357 * dup = 0 means all files differ 358 * dup = 1 means files 1 and 2 identical 359 */ 360 if (eflag==0) { 361 separate(dup ? "3" : ""); 362 change(1, &d1->old, dup); 363 change(2, &d2->old, 0); 364 d3 = d1->old.to > d1->old.from ? d1 : d2; 365 change(3, &d3->new, 0); 366 } else 367 j = edit(d1, dup, j); 368 d1++; 369 d2++; 370 continue; 371 } 372 /* 373 * Overlapping changes from file 1 and 2; extend changes 374 * appropriately to make them coincide. 375 */ 376 if (d1->new.from < d2->new.from) { 377 d2->old.from -= d2->new.from-d1->new.from; 378 d2->new.from = d1->new.from; 379 } else if (d2->new.from < d1->new.from) { 380 d1->old.from -= d1->new.from-d2->new.from; 381 d1->new.from = d2->new.from; 382 } 383 if (d1->new.to > d2->new.to) { 384 d2->old.to += d1->new.to - d2->new.to; 385 d2->new.to = d1->new.to; 386 } else if (d2->new.to > d1->new.to) { 387 d1->old.to += d2->new.to - d1->new.to; 388 d1->new.to = d2->new.to; 389 } 390 } 391 if (eflag) 392 edscript(j); 393 } 394 395 void 396 separate(const char *s) 397 { 398 printf("====%s\n", s); 399 } 400 401 /* 402 * The range of lines rold.from thru rold.to in file i is to be changed. 403 * It is to be printed only if it does not duplicate something to be 404 * printed later. 405 */ 406 void 407 change(int i, struct range *rold, int dup) 408 { 409 printf("%d:", i); 410 last[i] = rold->to; 411 prange(rold); 412 if (dup || debug) 413 return; 414 i--; 415 (void)skip(i, rold->from, NULL); 416 (void)skip(i, rold->to, " "); 417 } 418 419 /* 420 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 421 */ 422 void 423 prange(struct range *rold) 424 { 425 if (rold->to <= rold->from) 426 printf("%da\n", rold->from - 1); 427 else { 428 printf("%d", rold->from); 429 if (rold->to > rold->from+1) 430 printf(",%d", rold->to - 1); 431 printf("c\n"); 432 } 433 } 434 435 /* 436 * No difference was reported by diff between file 1 (or 2) and file 3, 437 * and an artificial dummy difference (trange) must be ginned up to 438 * correspond to the change reported in the other file. 439 */ 440 void 441 keep(int i, struct range *rnew) 442 { 443 int delta; 444 struct range trange; 445 446 delta = last[3] - last[i]; 447 trange.from = rnew->from - delta; 448 trange.to = rnew->to - delta; 449 change(i, &trange, 1); 450 } 451 452 /* 453 * skip to just before line number from in file "i". If "pr" is non-NULL, 454 * print all skipped stuff with string pr as a prefix. 455 */ 456 int 457 skip(int i, int from, char *pr) 458 { 459 size_t j, n; 460 char *line; 461 462 for (n = 0; cline[i] < from - 1; n += j) { 463 if ((line = get_line(fp[i], &j)) == NULL) 464 trouble(); 465 if (pr != NULL) 466 printf("%s%s", pr, line); 467 cline[i]++; 468 } 469 return ((int) n); 470 } 471 472 /* 473 * Return 1 or 0 according as the old range (in file 1) contains exactly 474 * the same data as the new range (in file 2). 475 */ 476 int 477 duplicate(struct range *r1, struct range *r2) 478 { 479 int c,d; 480 int nchar; 481 int nline; 482 483 if (r1->to-r1->from != r2->to-r2->from) 484 return (0); 485 (void)skip(0, r1->from, NULL); 486 (void)skip(1, r2->from, NULL); 487 nchar = 0; 488 for (nline=0; nline < r1->to - r1->from; nline++) { 489 do { 490 c = getc(fp[0]); 491 d = getc(fp[1]); 492 if (c == -1 || d== -1) 493 trouble(); 494 nchar++; 495 if (c != d) { 496 repos(nchar); 497 return (0); 498 } 499 } while (c != '\n'); 500 } 501 repos(nchar); 502 return (1); 503 } 504 505 void 506 repos(int nchar) 507 { 508 int i; 509 510 for (i = 0; i < 2; i++) 511 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 512 } 513 514 __dead void 515 trouble(void) 516 { 517 errx(EXIT_FAILURE, "logic error"); 518 } 519 520 /* 521 * collect an editing script for later regurgitation 522 */ 523 int 524 edit(struct diff *diff, int dup, int j) 525 { 526 if (((dup + 1) & eflag) == 0) 527 return (j); 528 j++; 529 overlap[j] = !dup; 530 if (!dup) 531 overlapcnt++; 532 de[j].old.from = diff->old.from; 533 de[j].old.to = diff->old.to; 534 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 535 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 536 return (j); 537 } 538 539 /* regurgitate */ 540 __dead void 541 edscript(int n) 542 { 543 int j,k; 544 char block[BUFSIZ]; 545 546 for (n = n; n > 0; n--) { 547 if (!oflag || !overlap[n]) 548 prange(&de[n].old); 549 else 550 printf("%da\n=======\n", de[n].old.to -1); 551 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 552 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 553 j = k > BUFSIZ ? BUFSIZ : k; 554 if (fread(block, 1, j, fp[2]) != j) 555 trouble(); 556 (void)fwrite(block, 1, j, stdout); 557 } 558 if (!oflag || !overlap[n]) 559 printf(".\n"); 560 else { 561 printf("%s\n.\n", f3mark); 562 printf("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 563 } 564 } 565 exit(overlapcnt); 566 } 567 568 void 569 increase(void) 570 { 571 struct diff *p; 572 char *q; 573 size_t newsz, incr; 574 575 /* are the memset(3) calls needed? */ 576 newsz = szchanges == 0 ? 64 : 2 * szchanges; 577 incr = newsz - szchanges; 578 579 p = reallocarray(d13, newsz, sizeof(struct diff)); 580 if (p == NULL) 581 err(1, NULL); 582 memset(p + szchanges, 0, incr * sizeof(struct diff)); 583 d13 = p; 584 p = reallocarray(d23, newsz, sizeof(struct diff)); 585 if (p == NULL) 586 err(1, NULL); 587 memset(p + szchanges, 0, incr * sizeof(struct diff)); 588 d23 = p; 589 p = reallocarray(de, newsz, sizeof(struct diff)); 590 if (p == NULL) 591 err(1, NULL); 592 memset(p + szchanges, 0, incr * sizeof(struct diff)); 593 de = p; 594 q = reallocarray(overlap, newsz, sizeof(char)); 595 if (q == NULL) 596 err(1, NULL); 597 memset(q + szchanges, 0, incr * sizeof(char)); 598 overlap = q; 599 szchanges = newsz; 600 } 601 602 603 __dead void 604 usage(void) 605 { 606 extern char *__progname; 607 608 fprintf(stderr, "usage: %s [-exEX3] /tmp/d3a.?????????? " 609 "/tmp/d3b.?????????? file1 file2 file3\n", __progname); 610 exit(EXIT_FAILURE); 611 } 612