1 /* $OpenBSD: diff3prog.c,v 1.13 2013/11/15 22:20:04 millert 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 eflag = 0; 149 oflag = 0; 150 while ((ch = getopt(argc, argv, "EeXx3")) != -1) { 151 switch (ch) { 152 case 'E': 153 eflag = 3; 154 oflag = 1; 155 break; 156 case 'e': 157 eflag = 3; 158 break; 159 case 'X': 160 oflag = eflag = 1; 161 break; 162 case 'x': 163 eflag = 1; 164 break; 165 case '3': 166 eflag = 2; 167 break; 168 } 169 } 170 argc -= optind; 171 argv += optind; 172 /* XXX - argc usage seems wrong here */ 173 if (argc < 5) 174 usage(); 175 176 if (oflag) { 177 (void)snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", 178 argc >= 6 ? argv[5] : argv[2]); 179 (void)snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", 180 argc >= 7 ? argv[6] : argv[4]); 181 } 182 183 increase(); 184 m = readin(argv[0], &d13); 185 n = readin(argv[1], &d23); 186 for (i = 0; i <= 2; i++) { 187 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) 188 err(EXIT_FAILURE, "can't open %s", argv[i + 2]); 189 } 190 merge(m, n); 191 exit(EXIT_SUCCESS); 192 } 193 194 /* 195 * Pick up the line numbers of all changes from one change file. 196 * (This puts the numbers in a vector, which is not strictly necessary, 197 * since the vector is processed in one sequential pass. 198 * The vector could be optimized out of existence) 199 */ 200 int 201 readin(char *name, struct diff **dd) 202 { 203 int a, b, c, d, i; 204 char kind, *p; 205 206 fp[0] = fopen(name, "r"); 207 if (fp[0] == NULL) 208 err(EXIT_FAILURE, "can't open %s", name); 209 for (i=0; (p = getchange(fp[0])); i++) { 210 if (i >= szchanges - 1) 211 increase(); 212 a = b = number(&p); 213 if (*p == ',') { 214 p++; 215 b = number(&p); 216 } 217 kind = *p++; 218 c = d = number(&p); 219 if (*p==',') { 220 p++; 221 d = number(&p); 222 } 223 if (kind == 'a') 224 a++; 225 if (kind == 'd') 226 c++; 227 b++; 228 d++; 229 (*dd)[i].old.from = a; 230 (*dd)[i].old.to = b; 231 (*dd)[i].new.from = c; 232 (*dd)[i].new.to = d; 233 } 234 if (i) { 235 (*dd)[i].old.from = (*dd)[i-1].old.to; 236 (*dd)[i].new.from = (*dd)[i-1].new.to; 237 } 238 (void)fclose(fp[0]); 239 return (i); 240 } 241 242 int 243 number(char **lc) 244 { 245 int nn; 246 nn = 0; 247 while (isdigit((unsigned char)(**lc))) 248 nn = nn*10 + *(*lc)++ - '0'; 249 return (nn); 250 } 251 252 char * 253 getchange(FILE *b) 254 { 255 char *line; 256 257 while ((line = get_line(b, NULL))) { 258 if (isdigit((unsigned char)line[0])) 259 return (line); 260 } 261 return (NULL); 262 } 263 264 char * 265 get_line(FILE *b, size_t *n) 266 { 267 char *cp; 268 size_t len; 269 static char *buf; 270 static size_t bufsize; 271 272 if ((cp = fgetln(b, &len)) == NULL) 273 return (NULL); 274 275 if (cp[len - 1] != '\n') 276 len++; 277 if (len + 1 > bufsize) { 278 do { 279 bufsize += 1024; 280 } while (len + 1 > bufsize); 281 if ((buf = realloc(buf, bufsize)) == NULL) 282 err(EXIT_FAILURE, NULL); 283 } 284 memcpy(buf, cp, len - 1); 285 buf[len - 1] = '\n'; 286 buf[len] = '\0'; 287 if (n != NULL) 288 *n = len; 289 return (buf); 290 } 291 292 void 293 merge(int m1, int m2) 294 { 295 struct diff *d1, *d2, *d3; 296 int dup, j, t1, t2; 297 298 d1 = d13; 299 d2 = d23; 300 j = 0; 301 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 302 if (debug) { 303 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 304 d1->old.from,d1->old.to, 305 d1->new.from,d1->new.to, 306 d2->old.from,d2->old.to, 307 d2->new.from,d2->new.to); 308 } 309 /* first file is different from others */ 310 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 311 /* stuff peculiar to 1st file */ 312 if (eflag==0) { 313 separate("1"); 314 change(1, &d1->old, 0); 315 keep(2, &d1->new); 316 change(3, &d1->new, 0); 317 } 318 d1++; 319 continue; 320 } 321 /* second file is different from others */ 322 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 323 if (eflag==0) { 324 separate("2"); 325 keep(1, &d2->new); 326 change(2, &d2->old, 0); 327 change(3, &d2->new, 0); 328 } 329 d2++; 330 continue; 331 } 332 /* 333 * Merge overlapping changes in first file 334 * this happens after extension (see below). 335 */ 336 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 337 d1[1].old.from = d1->old.from; 338 d1[1].new.from = d1->new.from; 339 d1++; 340 continue; 341 } 342 343 /* merge overlapping changes in second */ 344 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 345 d2[1].old.from = d2->old.from; 346 d2[1].new.from = d2->new.from; 347 d2++; 348 continue; 349 } 350 /* stuff peculiar to third file or different in all */ 351 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 352 dup = duplicate(&d1->old,&d2->old); 353 /* 354 * dup = 0 means all files differ 355 * dup = 1 means files 1 and 2 identical 356 */ 357 if (eflag==0) { 358 separate(dup ? "3" : ""); 359 change(1, &d1->old, dup); 360 change(2, &d2->old, 0); 361 d3 = d1->old.to > d1->old.from ? d1 : d2; 362 change(3, &d3->new, 0); 363 } else 364 j = edit(d1, dup, j); 365 d1++; 366 d2++; 367 continue; 368 } 369 /* 370 * Overlapping changes from file 1 and 2; extend changes 371 * appropriately to make them coincide. 372 */ 373 if (d1->new.from < d2->new.from) { 374 d2->old.from -= d2->new.from-d1->new.from; 375 d2->new.from = d1->new.from; 376 } else if (d2->new.from < d1->new.from) { 377 d1->old.from -= d1->new.from-d2->new.from; 378 d1->new.from = d2->new.from; 379 } 380 if (d1->new.to > d2->new.to) { 381 d2->old.to += d1->new.to - d2->new.to; 382 d2->new.to = d1->new.to; 383 } else if (d2->new.to > d1->new.to) { 384 d1->old.to += d2->new.to - d1->new.to; 385 d1->new.to = d2->new.to; 386 } 387 } 388 if (eflag) 389 edscript(j); 390 } 391 392 void 393 separate(const char *s) 394 { 395 printf("====%s\n", s); 396 } 397 398 /* 399 * The range of lines rold.from thru rold.to in file i is to be changed. 400 * It is to be printed only if it does not duplicate something to be 401 * printed later. 402 */ 403 void 404 change(int i, struct range *rold, int dup) 405 { 406 printf("%d:", i); 407 last[i] = rold->to; 408 prange(rold); 409 if (dup || debug) 410 return; 411 i--; 412 (void)skip(i, rold->from, NULL); 413 (void)skip(i, rold->to, " "); 414 } 415 416 /* 417 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 418 */ 419 void 420 prange(struct range *rold) 421 { 422 if (rold->to <= rold->from) 423 printf("%da\n", rold->from - 1); 424 else { 425 printf("%d", rold->from); 426 if (rold->to > rold->from+1) 427 printf(",%d", rold->to - 1); 428 printf("c\n"); 429 } 430 } 431 432 /* 433 * No difference was reported by diff between file 1 (or 2) and file 3, 434 * and an artificial dummy difference (trange) must be ginned up to 435 * correspond to the change reported in the other file. 436 */ 437 void 438 keep(int i, struct range *rnew) 439 { 440 int delta; 441 struct range trange; 442 443 delta = last[3] - last[i]; 444 trange.from = rnew->from - delta; 445 trange.to = rnew->to - delta; 446 change(i, &trange, 1); 447 } 448 449 /* 450 * skip to just before line number from in file "i". If "pr" is non-NULL, 451 * print all skipped stuff with string pr as a prefix. 452 */ 453 int 454 skip(int i, int from, char *pr) 455 { 456 size_t j, n; 457 char *line; 458 459 for (n = 0; cline[i] < from - 1; n += j) { 460 if ((line = get_line(fp[i], &j)) == NULL) 461 trouble(); 462 if (pr != NULL) 463 printf("%s%s", pr, line); 464 cline[i]++; 465 } 466 return ((int) n); 467 } 468 469 /* 470 * Return 1 or 0 according as the old range (in file 1) contains exactly 471 * the same data as the new range (in file 2). 472 */ 473 int 474 duplicate(struct range *r1, struct range *r2) 475 { 476 int c,d; 477 int nchar; 478 int nline; 479 480 if (r1->to-r1->from != r2->to-r2->from) 481 return (0); 482 (void)skip(0, r1->from, NULL); 483 (void)skip(1, r2->from, NULL); 484 nchar = 0; 485 for (nline=0; nline < r1->to - r1->from; nline++) { 486 do { 487 c = getc(fp[0]); 488 d = getc(fp[1]); 489 if (c == -1 || d== -1) 490 trouble(); 491 nchar++; 492 if (c != d) { 493 repos(nchar); 494 return (0); 495 } 496 } while (c != '\n'); 497 } 498 repos(nchar); 499 return (1); 500 } 501 502 void 503 repos(int nchar) 504 { 505 int i; 506 507 for (i = 0; i < 2; i++) 508 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 509 } 510 511 __dead void 512 trouble(void) 513 { 514 errx(EXIT_FAILURE, "logic error"); 515 } 516 517 /* 518 * collect an editing script for later regurgitation 519 */ 520 int 521 edit(struct diff *diff, int dup, int j) 522 { 523 if (((dup + 1) & eflag) == 0) 524 return (j); 525 j++; 526 overlap[j] = !dup; 527 if (!dup) 528 overlapcnt++; 529 de[j].old.from = diff->old.from; 530 de[j].old.to = diff->old.to; 531 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 532 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 533 return (j); 534 } 535 536 /* regurgitate */ 537 __dead void 538 edscript(int n) 539 { 540 int j,k; 541 char block[BUFSIZ]; 542 543 for (n = n; n > 0; n--) { 544 if (!oflag || !overlap[n]) 545 prange(&de[n].old); 546 else 547 printf("%da\n=======\n", de[n].old.to -1); 548 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 549 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 550 j = k > BUFSIZ ? BUFSIZ : k; 551 if (fread(block, 1, j, fp[2]) != j) 552 trouble(); 553 (void)fwrite(block, 1, j, stdout); 554 } 555 if (!oflag || !overlap[n]) 556 printf(".\n"); 557 else { 558 printf("%s\n.\n", f3mark); 559 printf("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 560 } 561 } 562 exit(overlapcnt); 563 } 564 565 void 566 increase(void) 567 { 568 struct diff *p; 569 char *q; 570 size_t newsz, incr; 571 572 /* are the memset(3) calls needed? */ 573 newsz = szchanges == 0 ? 64 : 2 * szchanges; 574 incr = newsz - szchanges; 575 576 p = realloc(d13, newsz * sizeof(struct diff)); 577 if (p == NULL) 578 err(1, NULL); 579 memset(p + szchanges, 0, incr * sizeof(struct diff)); 580 d13 = p; 581 p = realloc(d23, newsz * sizeof(struct diff)); 582 if (p == NULL) 583 err(1, NULL); 584 memset(p + szchanges, 0, incr * sizeof(struct diff)); 585 d23 = p; 586 p = realloc(de, newsz * sizeof(struct diff)); 587 if (p == NULL) 588 err(1, NULL); 589 memset(p + szchanges, 0, incr * sizeof(struct diff)); 590 de = p; 591 q = realloc(overlap, newsz * sizeof(char)); 592 if (q == NULL) 593 err(1, NULL); 594 memset(q + szchanges, 0, incr * sizeof(char)); 595 overlap = q; 596 szchanges = newsz; 597 } 598 599 600 __dead void 601 usage(void) 602 { 603 extern char *__progname; 604 605 fprintf(stderr, "usage: %s [-exEX3] /tmp/d3a.?????????? " 606 "/tmp/d3b.?????????? file1 file2 file3\n", __progname); 607 exit(EXIT_FAILURE); 608 } 609