1 /* $OpenBSD: diff3prog.c,v 1.6 2005/03/30 04:44:52 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 #ifndef lint 68 static const char copyright[] = 69 "@(#) Copyright (c) 1991, 1993\n\ 70 The Regents of the University of California. All rights reserved.\n"; 71 #endif /* not lint */ 72 73 #ifndef lint 74 static const char rcsid[] = "$OpenBSD: diff3prog.c,v 1.6 2005/03/30 04:44:52 millert Exp $"; 75 #endif /* not lint */ 76 77 #include <stdio.h> 78 #include <stdlib.h> 79 #include <string.h> 80 #include <ctype.h> 81 #include <err.h> 82 83 /* diff3 - 3-way differential file comparison */ 84 85 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 86 * 87 * d13 = diff report on f1 vs f3 88 * d23 = diff report on f2 vs f3 89 * f1, f2, f3 the 3 files 90 * if changes in f1 overlap with changes in f3, m1 and m3 are used 91 * to mark the overlaps; otherwise, the file names f1 and f3 are used 92 * (only for options E and X). 93 */ 94 95 /* 96 * "from" is first in range of changed lines; "to" is last+1 97 * from=to=line after point of insertion for added lines. 98 */ 99 struct range { 100 int from; 101 int to; 102 }; 103 struct diff { 104 struct range old; 105 struct range new; 106 }; 107 108 #define NC 200 109 struct diff d13[NC]; 110 struct diff d23[NC]; 111 /* 112 * "de" is used to gather editing scripts. These are later spewed out in 113 * reverse order. Its first element must be all zero, the "new" component 114 * of "de" contains line positions or byte positions depending on when you 115 * look (!?). Array overlap indicates which sections in "de" correspond to 116 * lines that are different in all three files. 117 */ 118 struct diff de[NC]; 119 char overlap[NC]; 120 int overlapcnt; 121 FILE *fp[3]; 122 int cline[3]; /* # of the last-read line in each file (0-2) */ 123 /* 124 * the latest known correspondence between line numbers of the 3 files 125 * is stored in last[1-3]; 126 */ 127 int last[4]; 128 int eflag; 129 int oflag; /* indicates whether to mark overlaps (-E or -X)*/ 130 int debug = 0; 131 char f1mark[40], f3mark[40]; /* markers for -E and -X */ 132 133 int duplicate(struct range *, struct range *); 134 int edit(struct diff *, int, int); 135 char *getchange(FILE *); 136 char *getline(FILE *, size_t *); 137 int number(char **); 138 int readin(char *, struct diff *); 139 int skip(int, int, char *); 140 void change(int, struct range *, int); 141 void keep(int, struct range *); 142 void merge(int, int); 143 void prange(struct range *); 144 void repos(int); 145 void separate(const char *); 146 __dead void edscript(int); 147 __dead void trouble(void); 148 __dead void usage(void); 149 150 int 151 main(int argc, char **argv) 152 { 153 int ch, i, m, n; 154 155 eflag = 0; 156 oflag = 0; 157 while ((ch = getopt(argc, argv, "EeXx3")) != -1) { 158 switch (ch) { 159 case 'E': 160 eflag = 3; 161 oflag = 1; 162 break; 163 case 'e': 164 eflag = 3; 165 break; 166 case 'X': 167 oflag = eflag = 1; 168 break; 169 case 'x': 170 eflag = 1; 171 break; 172 case '3': 173 eflag = 2; 174 break; 175 } 176 } 177 argc -= optind; 178 argv += optind; 179 /* XXX - argc usage seems wrong here */ 180 if (argc < 5) 181 usage(); 182 183 if (oflag) { 184 (void)snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", 185 argc >= 6 ? argv[5] : argv[2]); 186 (void)snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", 187 argc >= 7 ? argv[6] : argv[4]); 188 } 189 190 m = readin(argv[0], d13); 191 n = readin(argv[1], d23); 192 for (i = 0; i <= 2; i++) { 193 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 194 printf("diff3: can't open %s\n", argv[i + 2]); 195 exit(EXIT_FAILURE); 196 } 197 } 198 merge(m, n); 199 exit(EXIT_SUCCESS); 200 } 201 202 /* 203 * Pick up the line numbers of all changes from one change file. 204 * (This puts the numbers in a vector, which is not strictly necessary, 205 * since the vector is processed in one sequential pass. 206 * The vector could be optimized out of existence) 207 */ 208 int 209 readin(char *name, struct diff *dd) 210 { 211 int a, b, c, d, i; 212 char kind, *p; 213 214 fp[0] = fopen(name, "r"); 215 for (i=0; (p = getchange(fp[0])); i++) { 216 if (i >= NC) 217 err(EXIT_FAILURE, "too many changes"); 218 a = b = number(&p); 219 if (*p == ',') { 220 p++; 221 b = number(&p); 222 } 223 kind = *p++; 224 c = d = number(&p); 225 if (*p==',') { 226 p++; 227 d = number(&p); 228 } 229 if (kind == 'a') 230 a++; 231 if (kind == 'd') 232 c++; 233 b++; 234 d++; 235 dd[i].old.from = a; 236 dd[i].old.to = b; 237 dd[i].new.from = c; 238 dd[i].new.to = d; 239 } 240 dd[i].old.from = dd[i-1].old.to; 241 dd[i].new.from = dd[i-1].new.to; 242 (void)fclose(fp[0]); 243 return (i); 244 } 245 246 int 247 number(char **lc) 248 { 249 int nn; 250 nn = 0; 251 while (isdigit((unsigned char)(**lc))) 252 nn = nn*10 + *(*lc)++ - '0'; 253 return (nn); 254 } 255 256 char * 257 getchange(FILE *b) 258 { 259 char *line; 260 261 while ((line = getline(b, NULL))) { 262 if (isdigit((unsigned char)line[0])) 263 return (line); 264 } 265 return (NULL); 266 } 267 268 char * 269 getline(FILE *b, size_t *n) 270 { 271 char *cp; 272 size_t len; 273 static char *buf; 274 static size_t bufsize; 275 276 if ((cp = fgetln(b, &len)) == NULL) 277 return (NULL); 278 279 if (cp[len - 1] != '\n') 280 len++; 281 if (len + 1 > bufsize) { 282 do { 283 bufsize += 1024; 284 } while (len + 1 > bufsize); 285 if ((buf = realloc(buf, bufsize)) == NULL) 286 err(EXIT_FAILURE, NULL); 287 } 288 memcpy(buf, cp, len - 1); 289 buf[len - 1] = '\n'; 290 buf[len] = '\0'; 291 if (n != NULL) 292 *n = len; 293 return (buf); 294 } 295 296 void 297 merge(int m1, int m2) 298 { 299 struct diff *d1, *d2, *d3; 300 int dup, j, t1, t2; 301 302 d1 = d13; 303 d2 = d23; 304 j = 0; 305 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 306 if (debug) { 307 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 308 d1->old.from,d1->old.to, 309 d1->new.from,d1->new.to, 310 d2->old.from,d2->old.to, 311 d2->new.from,d2->new.to); 312 } 313 /* first file is different from others */ 314 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 315 /* stuff peculiar to 1st file */ 316 if (eflag==0) { 317 separate("1"); 318 change(1, &d1->old, 0); 319 keep(2, &d1->new); 320 change(3, &d1->new, 0); 321 } 322 d1++; 323 continue; 324 } 325 /* second file is different from others */ 326 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 327 if (eflag==0) { 328 separate("2"); 329 keep(1, &d2->new); 330 change(2, &d2->old, 0); 331 change(3, &d2->new, 0); 332 } 333 d2++; 334 continue; 335 } 336 /* 337 * Merge overlapping changes in first file 338 * this happens after extension (see below). 339 */ 340 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 341 d1[1].old.from = d1->old.from; 342 d1[1].new.from = d1->new.from; 343 d1++; 344 continue; 345 } 346 347 /* merge overlapping changes in second */ 348 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 349 d2[1].old.from = d2->old.from; 350 d2[1].new.from = d2->new.from; 351 d2++; 352 continue; 353 } 354 /* stuff peculiar to third file or different in all */ 355 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 356 dup = duplicate(&d1->old,&d2->old); 357 /* 358 * dup = 0 means all files differ 359 * dup = 1 means files 1 and 2 identical 360 */ 361 if (eflag==0) { 362 separate(dup ? "3" : ""); 363 change(1, &d1->old, dup); 364 change(2, &d2->old, 0); 365 d3 = d1->old.to > d1->old.from ? d1 : d2; 366 change(3, &d3->new, 0); 367 } else 368 j = edit(d1, dup, j); 369 d1++; 370 d2++; 371 continue; 372 } 373 /* 374 * Overlapping changes from file 1 and 2; extend changes 375 * appropriately to make them coincide. 376 */ 377 if (d1->new.from < d2->new.from) { 378 d2->old.from -= d2->new.from-d1->new.from; 379 d2->new.from = d1->new.from; 380 } else if (d2->new.from < d1->new.from) { 381 d1->old.from -= d1->new.from-d2->new.from; 382 d1->new.from = d2->new.from; 383 } 384 if (d1->new.to > d2->new.to) { 385 d2->old.to += d1->new.to - d2->new.to; 386 d2->new.to = d1->new.to; 387 } else if (d2->new.to > d1->new.to) { 388 d1->old.to += d2->new.to - d1->new.to; 389 d1->new.to = d2->new.to; 390 } 391 } 392 if (eflag) 393 edscript(j); 394 } 395 396 void 397 separate(const char *s) 398 { 399 printf("====%s\n", s); 400 } 401 402 /* 403 * The range of lines rold.from thru rold.to in file i is to be changed. 404 * It is to be printed only if it does not duplicate something to be 405 * printed later. 406 */ 407 void 408 change(int i, struct range *rold, int dup) 409 { 410 printf("%d:", i); 411 last[i] = rold->to; 412 prange(rold); 413 if (dup || debug) 414 return; 415 i--; 416 (void)skip(i, rold->from, NULL); 417 (void)skip(i, rold->to, " "); 418 } 419 420 /* 421 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 422 */ 423 void 424 prange(struct range *rold) 425 { 426 if (rold->to <= rold->from) 427 printf("%da\n", rold->from - 1); 428 else { 429 printf("%d", rold->from); 430 if (rold->to > rold->from+1) 431 printf(",%d", rold->to - 1); 432 printf("c\n"); 433 } 434 } 435 436 /* 437 * No difference was reported by diff between file 1 (or 2) and file 3, 438 * and an artificial dummy difference (trange) must be ginned up to 439 * correspond to the change reported in the other file. 440 */ 441 void 442 keep(int i, struct range *rnew) 443 { 444 int delta; 445 struct range trange; 446 447 delta = last[3] - last[i]; 448 trange.from = rnew->from - delta; 449 trange.to = rnew->to - delta; 450 change(i, &trange, 1); 451 } 452 453 /* 454 * skip to just before line number from in file "i". If "pr" is non-NULL, 455 * print all skipped stuff with string pr as a prefix. 456 */ 457 int 458 skip(int i, int from, char *pr) 459 { 460 size_t j, n; 461 char *line; 462 463 for (n = 0; cline[i] < from - 1; n += j) { 464 if ((line = getline(fp[i], &j)) == NULL) 465 trouble(); 466 if (pr != NULL) 467 printf("%s%s", pr, line); 468 cline[i]++; 469 } 470 return ((int) n); 471 } 472 473 /* 474 * Return 1 or 0 according as the old range (in file 1) contains exactly 475 * the same data as the new range (in file 2). 476 */ 477 int 478 duplicate(struct range *r1, struct range *r2) 479 { 480 int c,d; 481 int nchar; 482 int nline; 483 484 if (r1->to-r1->from != r2->to-r2->from) 485 return (0); 486 (void)skip(0, r1->from, NULL); 487 (void)skip(1, r2->from, NULL); 488 nchar = 0; 489 for (nline=0; nline < r1->to - r1->from; nline++) { 490 do { 491 c = getc(fp[0]); 492 d = getc(fp[1]); 493 if (c == -1 || d== -1) 494 trouble(); 495 nchar++; 496 if (c != d) { 497 repos(nchar); 498 return (0); 499 } 500 } while (c != '\n'); 501 } 502 repos(nchar); 503 return (1); 504 } 505 506 void 507 repos(int nchar) 508 { 509 int i; 510 511 for (i = 0; i < 2; i++) 512 (void)fseek(fp[i], (long)-nchar, 1); 513 } 514 515 __dead void 516 trouble(void) 517 { 518 errx(EXIT_FAILURE, "logic error"); 519 } 520 521 /* 522 * collect an editing script for later regurgitation 523 */ 524 int 525 edit(struct diff *diff, int dup, int j) 526 { 527 if (((dup + 1) & eflag) == 0) 528 return (j); 529 j++; 530 overlap[j] = !dup; 531 if (!dup) 532 overlapcnt++; 533 de[j].old.from = diff->old.from; 534 de[j].old.to = diff->old.to; 535 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 536 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 537 return (j); 538 } 539 540 /* regurgitate */ 541 __dead void 542 edscript(int n) 543 { 544 int j,k; 545 char block[BUFSIZ]; 546 547 for (n = n; n > 0; n--) { 548 if (!oflag || !overlap[n]) 549 prange(&de[n].old); 550 else 551 printf("%da\n=======\n", de[n].old.to -1); 552 (void)fseek(fp[2], (long)de[n].new.from, 0); 553 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 554 j = k > BUFSIZ ? BUFSIZ : k; 555 if (fread(block, 1, j, fp[2]) != j) 556 trouble(); 557 (void)fwrite(block, 1, j, stdout); 558 } 559 if (!oflag || !overlap[n]) 560 printf(".\n"); 561 else { 562 printf("%s\n.\n", f3mark); 563 printf("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 564 } 565 } 566 exit(overlapcnt); 567 } 568 569 __dead void 570 usage(void) 571 { 572 extern char *__progname; 573 574 fprintf(stderr, "usage: %s [-exEX3] /tmp/d3a.?????????? " 575 "/tmp/d3b.?????????? file1 file2 file3\n", __progname); 576 exit(EXIT_FAILURE); 577 } 578