1 /* $OpenBSD: diff3.c,v 1.32 2011/04/20 19:34:16 nicm 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 #include "diff.h" 75 #include "rcsprog.h" 76 77 /* diff3 - 3-way differential file comparison */ 78 79 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 80 * 81 * d13 = diff report on f1 vs f3 82 * d23 = diff report on f2 vs f3 83 * f1, f2, f3 the 3 files 84 * if changes in f1 overlap with changes in f3, m1 and m3 are used 85 * to mark the overlaps; otherwise, the file names f1 and f3 are used 86 * (only for options E and X). 87 */ 88 89 /* 90 * "from" is first in range of changed lines; "to" is last+1 91 * from=to=line after point of insertion for added lines. 92 */ 93 struct range { 94 int from; 95 int to; 96 }; 97 98 struct diff { 99 struct range old; 100 struct range new; 101 }; 102 103 static size_t szchanges; 104 105 static struct diff *d13; 106 static struct diff *d23; 107 108 /* 109 * "de" is used to gather editing scripts. These are later spewed out in 110 * reverse order. Its first element must be all zero, the "new" component 111 * of "de" contains line positions or byte positions depending on when you 112 * look (!?). Array overlap indicates which sections in "de" correspond to 113 * lines that are different in all three files. 114 */ 115 static struct diff *de; 116 static char *overlap; 117 static int overlapcnt = 0; 118 static FILE *fp[3]; 119 static int cline[3]; /* # of the last-read line in each file (0-2) */ 120 121 /* 122 * the latest known correspondence between line numbers of the 3 files 123 * is stored in last[1-3]; 124 */ 125 static int last[4]; 126 static int eflag = 3; /* default -E for compatibility with former RCS */ 127 static int oflag = 1; /* default -E for compatibility with former RCS */ 128 static int debug = 0; 129 static char f1mark[MAXPATHLEN], f3mark[MAXPATHLEN]; /* markers for -E and -X */ 130 131 static int duplicate(struct range *, struct range *); 132 static int edit(struct diff *, int, int); 133 static char *getchange(FILE *); 134 static char *getline(FILE *, size_t *); 135 static int number(char **); 136 static ssize_t readin(char *, struct diff **); 137 static int skip(int, int, char *); 138 static int edscript(int); 139 static int merge(size_t, size_t); 140 static void change(int, struct range *, int); 141 static void keep(int, struct range *); 142 static void prange(struct range *); 143 static void repos(int); 144 static void separate(const char *); 145 static void increase(void); 146 static int diff3_internal(int, char **, const char *, const char *); 147 148 int diff3_conflicts = 0; 149 150 /* 151 * For merge(1). 152 */ 153 BUF * 154 merge_diff3(char **av, int flags) 155 { 156 int argc; 157 char *argv[5], *dp13, *dp23, *path1, *path2, *path3; 158 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 159 u_char *data, *patch; 160 size_t dlen, plen; 161 162 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 163 dp13 = dp23 = path1 = path2 = path3 = NULL; 164 data = patch = NULL; 165 166 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 167 oflag = 0; 168 169 if ((b1 = buf_load(av[0])) == NULL) 170 goto out; 171 if ((b2 = buf_load(av[1])) == NULL) 172 goto out; 173 if ((b3 = buf_load(av[2])) == NULL) 174 goto out; 175 176 d1 = buf_alloc(128); 177 d2 = buf_alloc(128); 178 diffb = buf_alloc(128); 179 180 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 181 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 182 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 183 184 buf_write_stmp(b1, path1); 185 buf_write_stmp(b2, path2); 186 buf_write_stmp(b3, path3); 187 188 buf_free(b2); 189 b2 = NULL; 190 191 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 192 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 193 buf_free(diffb); 194 diffb = NULL; 195 goto out; 196 } 197 198 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 199 buf_write_stmp(d1, dp13); 200 201 buf_free(d1); 202 d1 = NULL; 203 204 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 205 buf_write_stmp(d2, dp23); 206 207 buf_free(d2); 208 d2 = NULL; 209 210 argc = 0; 211 diffbuf = diffb; 212 argv[argc++] = dp13; 213 argv[argc++] = dp23; 214 argv[argc++] = path1; 215 argv[argc++] = path2; 216 argv[argc++] = path3; 217 218 diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]); 219 if (diff3_conflicts < 0) { 220 buf_free(diffb); 221 diffb = NULL; 222 goto out; 223 } 224 225 plen = buf_len(diffb); 226 patch = buf_release(diffb); 227 dlen = buf_len(b1); 228 data = buf_release(b1); 229 230 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 231 goto out; 232 233 if (!(flags & QUIET) && diff3_conflicts != 0) 234 warnx("warning: overlaps or other problems during merge"); 235 236 out: 237 if (b2 != NULL) 238 buf_free(b2); 239 if (b3 != NULL) 240 buf_free(b3); 241 if (d1 != NULL) 242 buf_free(d1); 243 if (d2 != NULL) 244 buf_free(d2); 245 246 (void)unlink(path1); 247 (void)unlink(path2); 248 (void)unlink(path3); 249 (void)unlink(dp13); 250 (void)unlink(dp23); 251 252 if (path1 != NULL) 253 xfree(path1); 254 if (path2 != NULL) 255 xfree(path2); 256 if (path3 != NULL) 257 xfree(path3); 258 if (dp13 != NULL) 259 xfree(dp13); 260 if (dp23 != NULL) 261 xfree(dp23); 262 if (data != NULL) 263 xfree(data); 264 if (patch != NULL) 265 xfree(patch); 266 267 return (diffb); 268 } 269 270 BUF * 271 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 272 { 273 int argc; 274 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 275 char *dp13, *dp23, *path1, *path2, *path3; 276 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 277 size_t dlen, plen; 278 u_char *data, *patch; 279 280 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 281 dp13 = dp23 = path1 = path2 = path3 = NULL; 282 data = patch = NULL; 283 284 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 285 oflag = 0; 286 287 rcsnum_tostr(rev1, r1, sizeof(r1)); 288 rcsnum_tostr(rev2, r2, sizeof(r2)); 289 290 if ((b1 = buf_load(workfile)) == NULL) 291 goto out; 292 293 if (!(flags & QUIET)) 294 (void)fprintf(stderr, "retrieving revision %s\n", r1); 295 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 296 goto out; 297 298 if (!(flags & QUIET)) 299 (void)fprintf(stderr, "retrieving revision %s\n", r2); 300 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 301 goto out; 302 303 d1 = buf_alloc(128); 304 d2 = buf_alloc(128); 305 diffb = buf_alloc(128); 306 307 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 308 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 309 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 310 311 buf_write_stmp(b1, path1); 312 buf_write_stmp(b2, path2); 313 buf_write_stmp(b3, path3); 314 315 buf_free(b2); 316 b2 = NULL; 317 318 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 319 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 320 buf_free(diffb); 321 diffb = NULL; 322 goto out; 323 } 324 325 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 326 buf_write_stmp(d1, dp13); 327 328 buf_free(d1); 329 d1 = NULL; 330 331 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 332 buf_write_stmp(d2, dp23); 333 334 buf_free(d2); 335 d2 = NULL; 336 337 argc = 0; 338 diffbuf = diffb; 339 argv[argc++] = dp13; 340 argv[argc++] = dp23; 341 argv[argc++] = path1; 342 argv[argc++] = path2; 343 argv[argc++] = path3; 344 345 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 346 if (diff3_conflicts < 0) { 347 buf_free(diffb); 348 diffb = NULL; 349 goto out; 350 } 351 352 plen = buf_len(diffb); 353 patch = buf_release(diffb); 354 dlen = buf_len(b1); 355 data = buf_release(b1); 356 357 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 358 goto out; 359 360 if (!(flags & QUIET) && diff3_conflicts != 0) 361 warnx("warning: overlaps or other problems during merge"); 362 363 out: 364 if (b2 != NULL) 365 buf_free(b2); 366 if (b3 != NULL) 367 buf_free(b3); 368 if (d1 != NULL) 369 buf_free(d1); 370 if (d2 != NULL) 371 buf_free(d2); 372 373 (void)unlink(path1); 374 (void)unlink(path2); 375 (void)unlink(path3); 376 (void)unlink(dp13); 377 (void)unlink(dp23); 378 379 if (path1 != NULL) 380 xfree(path1); 381 if (path2 != NULL) 382 xfree(path2); 383 if (path3 != NULL) 384 xfree(path3); 385 if (dp13 != NULL) 386 xfree(dp13); 387 if (dp23 != NULL) 388 xfree(dp23); 389 if (data != NULL) 390 xfree(data); 391 if (patch != NULL) 392 xfree(patch); 393 394 return (diffb); 395 } 396 397 static int 398 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 399 { 400 ssize_t m, n; 401 int i; 402 403 if (argc < 5) 404 return (-1); 405 406 if (oflag) { 407 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 408 if (i < 0 || i >= (int)sizeof(f1mark)) 409 errx(1, "diff3_internal: string truncated"); 410 411 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 412 if (i < 0 || i >= (int)sizeof(f3mark)) 413 errx(1, "diff3_internal: string truncated"); 414 } 415 416 increase(); 417 if ((m = readin(argv[0], &d13)) < 0) { 418 warn("%s", argv[0]); 419 return (-1); 420 } 421 if ((n = readin(argv[1], &d23)) < 0) { 422 warn("%s", argv[1]); 423 return (-1); 424 } 425 426 for (i = 0; i <= 2; i++) 427 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 428 warn("%s", argv[i + 2]); 429 return (-1); 430 } 431 432 return (merge(m, n)); 433 } 434 435 int 436 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 437 { 438 char op, *ep; 439 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 440 int start, end, i, lineno; 441 u_char tmp; 442 443 dlp = TAILQ_FIRST(&(dlines->l_lines)); 444 lp = TAILQ_FIRST(&(plines->l_lines)); 445 446 end = 0; 447 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 448 lp = TAILQ_NEXT(lp, l_list)) { 449 /* Skip blank lines */ 450 if (lp->l_len < 2) 451 continue; 452 453 /* NUL-terminate line buffer for strtol() safety. */ 454 tmp = lp->l_line[lp->l_len - 1]; 455 lp->l_line[lp->l_len - 1] = '\0'; 456 457 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 458 op = lp->l_line[lp->l_len - 2]; 459 start = (int)strtol(lp->l_line, &ep, 10); 460 461 /* Restore the last byte of the buffer */ 462 lp->l_line[lp->l_len - 1] = tmp; 463 464 if (op == 'a') { 465 if (start > dlines->l_nblines || 466 start < 0 || *ep != 'a') 467 errx(1, "ed_patch_lines"); 468 } else if (op == 'c') { 469 if (start > dlines->l_nblines || 470 start < 0 || (*ep != ',' && *ep != 'c')) 471 errx(1, "ed_patch_lines"); 472 473 if (*ep == ',') { 474 ep++; 475 end = (int)strtol(ep, &ep, 10); 476 if (end < 0 || *ep != 'c') 477 errx(1, "ed_patch_lines"); 478 } else { 479 end = start; 480 } 481 } 482 483 484 for (;;) { 485 if (dlp == NULL) 486 break; 487 if (dlp->l_lineno == start) 488 break; 489 if (dlp->l_lineno > start) { 490 dlp = TAILQ_PREV(dlp, tqh, l_list); 491 } else if (dlp->l_lineno < start) { 492 ndlp = TAILQ_NEXT(dlp, l_list); 493 if (ndlp->l_lineno > start) 494 break; 495 dlp = ndlp; 496 } 497 } 498 499 if (dlp == NULL) 500 errx(1, "ed_patch_lines"); 501 502 503 if (op == 'c') { 504 insert_after = TAILQ_PREV(dlp, tqh, l_list); 505 for (i = 0; i <= (end - start); i++) { 506 ndlp = TAILQ_NEXT(dlp, l_list); 507 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 508 dlp = ndlp; 509 } 510 dlp = insert_after; 511 } 512 513 if (op == 'a' || op == 'c') { 514 for (;;) { 515 ndlp = lp; 516 lp = TAILQ_NEXT(lp, l_list); 517 if (lp == NULL) 518 errx(1, "ed_patch_lines"); 519 520 if (!memcmp(lp->l_line, ".", 1)) 521 break; 522 523 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 524 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 525 lp, l_list); 526 dlp = lp; 527 528 lp->l_lineno = start; 529 lp = ndlp; 530 } 531 } 532 533 /* 534 * always resort lines as the markers might be put at the 535 * same line as we first started editing. 536 */ 537 lineno = 0; 538 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 539 sort->l_lineno = lineno++; 540 dlines->l_nblines = lineno - 1; 541 } 542 543 return (0); 544 } 545 546 /* 547 * Pick up the line numbers of all changes from one change file. 548 * (This puts the numbers in a vector, which is not strictly necessary, 549 * since the vector is processed in one sequential pass. 550 * The vector could be optimized out of existence) 551 */ 552 static ssize_t 553 readin(char *name, struct diff **dd) 554 { 555 int a, b, c, d; 556 char kind, *p; 557 size_t i; 558 559 fp[0] = fopen(name, "r"); 560 if (fp[0] == NULL) 561 return (-1); 562 for (i = 0; (p = getchange(fp[0])); i++) { 563 if (i >= szchanges - 1) 564 increase(); 565 a = b = number(&p); 566 if (*p == ',') { 567 p++; 568 b = number(&p); 569 } 570 kind = *p++; 571 c = d = number(&p); 572 if (*p==',') { 573 p++; 574 d = number(&p); 575 } 576 if (kind == 'a') 577 a++; 578 if (kind == 'd') 579 c++; 580 b++; 581 d++; 582 (*dd)[i].old.from = a; 583 (*dd)[i].old.to = b; 584 (*dd)[i].new.from = c; 585 (*dd)[i].new.to = d; 586 } 587 588 if (i) { 589 (*dd)[i].old.from = (*dd)[i-1].old.to; 590 (*dd)[i].new.from = (*dd)[i-1].new.to; 591 } 592 593 (void)fclose(fp[0]); 594 595 return (i); 596 } 597 598 static int 599 number(char **lc) 600 { 601 int nn; 602 603 nn = 0; 604 while (isdigit((unsigned char)(**lc))) 605 nn = nn*10 + *(*lc)++ - '0'; 606 607 return (nn); 608 } 609 610 static char * 611 getchange(FILE *b) 612 { 613 char *line; 614 615 while ((line = getline(b, NULL))) { 616 if (isdigit((unsigned char)line[0])) 617 return (line); 618 } 619 620 return (NULL); 621 } 622 623 static char * 624 getline(FILE *b, size_t *n) 625 { 626 char *cp; 627 size_t len; 628 static char *buf; 629 static size_t bufsize; 630 631 if ((cp = fgetln(b, &len)) == NULL) 632 return (NULL); 633 634 if (cp[len - 1] != '\n') 635 len++; 636 if (len + 1 > bufsize) { 637 do { 638 bufsize += 1024; 639 } while (len + 1 > bufsize); 640 buf = xrealloc(buf, 1, bufsize); 641 } 642 memcpy(buf, cp, len - 1); 643 buf[len - 1] = '\n'; 644 buf[len] = '\0'; 645 if (n != NULL) 646 *n = len; 647 648 return (buf); 649 } 650 651 static int 652 merge(size_t m1, size_t m2) 653 { 654 struct diff *d1, *d2, *d3; 655 int dpl, j, t1, t2; 656 657 d1 = d13; 658 d2 = d23; 659 j = 0; 660 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 661 if (debug) { 662 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 663 d1->old.from, d1->old.to, 664 d1->new.from, d1->new.to, 665 d2->old.from, d2->old.to, 666 d2->new.from, d2->new.to); 667 } 668 669 /* first file is different from others */ 670 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 671 /* stuff peculiar to 1st file */ 672 if (eflag==0) { 673 separate("1"); 674 change(1, &d1->old, 0); 675 keep(2, &d1->new); 676 change(3, &d1->new, 0); 677 } 678 d1++; 679 continue; 680 } 681 682 /* second file is different from others */ 683 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 684 if (eflag==0) { 685 separate("2"); 686 keep(1, &d2->new); 687 change(2, &d2->old, 0); 688 change(3, &d2->new, 0); 689 } 690 d2++; 691 continue; 692 } 693 694 /* 695 * Merge overlapping changes in first file 696 * this happens after extension (see below). 697 */ 698 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 699 d1[1].old.from = d1->old.from; 700 d1[1].new.from = d1->new.from; 701 d1++; 702 continue; 703 } 704 705 /* merge overlapping changes in second */ 706 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 707 d2[1].old.from = d2->old.from; 708 d2[1].new.from = d2->new.from; 709 d2++; 710 continue; 711 } 712 /* stuff peculiar to third file or different in all */ 713 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 714 dpl = duplicate(&d1->old,&d2->old); 715 if (dpl == -1) 716 return (-1); 717 718 /* 719 * dpl = 0 means all files differ 720 * dpl = 1 means files 1 and 2 identical 721 */ 722 if (eflag==0) { 723 separate(dpl ? "3" : ""); 724 change(1, &d1->old, dpl); 725 change(2, &d2->old, 0); 726 d3 = d1->old.to > d1->old.from ? d1 : d2; 727 change(3, &d3->new, 0); 728 } else 729 j = edit(d1, dpl, j); 730 d1++; 731 d2++; 732 continue; 733 } 734 735 /* 736 * Overlapping changes from file 1 and 2; extend changes 737 * appropriately to make them coincide. 738 */ 739 if (d1->new.from < d2->new.from) { 740 d2->old.from -= d2->new.from-d1->new.from; 741 d2->new.from = d1->new.from; 742 } else if (d2->new.from < d1->new.from) { 743 d1->old.from -= d1->new.from-d2->new.from; 744 d1->new.from = d2->new.from; 745 } 746 if (d1->new.to > d2->new.to) { 747 d2->old.to += d1->new.to - d2->new.to; 748 d2->new.to = d1->new.to; 749 } else if (d2->new.to > d1->new.to) { 750 d1->old.to += d2->new.to - d1->new.to; 751 d1->new.to = d2->new.to; 752 } 753 } 754 755 return (edscript(j)); 756 } 757 758 static void 759 separate(const char *s) 760 { 761 diff_output("====%s\n", s); 762 } 763 764 /* 765 * The range of lines rold.from thru rold.to in file i is to be changed. 766 * It is to be printed only if it does not duplicate something to be 767 * printed later. 768 */ 769 static void 770 change(int i, struct range *rold, int fdup) 771 { 772 diff_output("%d:", i); 773 last[i] = rold->to; 774 prange(rold); 775 if (fdup || debug) 776 return; 777 i--; 778 (void)skip(i, rold->from, NULL); 779 (void)skip(i, rold->to, " "); 780 } 781 782 /* 783 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 784 */ 785 static void 786 prange(struct range *rold) 787 { 788 if (rold->to <= rold->from) 789 diff_output("%da\n", rold->from - 1); 790 else { 791 diff_output("%d", rold->from); 792 if (rold->to > rold->from+1) 793 diff_output(",%d", rold->to - 1); 794 diff_output("c\n"); 795 } 796 } 797 798 /* 799 * No difference was reported by diff between file 1 (or 2) and file 3, 800 * and an artificial dummy difference (trange) must be ginned up to 801 * correspond to the change reported in the other file. 802 */ 803 static void 804 keep(int i, struct range *rnew) 805 { 806 int delta; 807 struct range trange; 808 809 delta = last[3] - last[i]; 810 trange.from = rnew->from - delta; 811 trange.to = rnew->to - delta; 812 change(i, &trange, 1); 813 } 814 815 /* 816 * skip to just before line number from in file "i". If "pr" is non-NULL, 817 * print all skipped stuff with string pr as a prefix. 818 */ 819 static int 820 skip(int i, int from, char *pr) 821 { 822 size_t j, n; 823 char *line; 824 825 for (n = 0; cline[i] < from - 1; n += j) { 826 if ((line = getline(fp[i], &j)) == NULL) 827 return (-1); 828 if (pr != NULL) 829 diff_output("%s%s", pr, line); 830 cline[i]++; 831 } 832 return ((int) n); 833 } 834 835 /* 836 * Return 1 or 0 according as the old range (in file 1) contains exactly 837 * the same data as the new range (in file 2). 838 */ 839 static int 840 duplicate(struct range *r1, struct range *r2) 841 { 842 int c,d; 843 int nchar; 844 int nline; 845 846 if (r1->to-r1->from != r2->to-r2->from) 847 return (0); 848 (void)skip(0, r1->from, NULL); 849 (void)skip(1, r2->from, NULL); 850 nchar = 0; 851 for (nline=0; nline < r1->to - r1->from; nline++) { 852 do { 853 c = getc(fp[0]); 854 d = getc(fp[1]); 855 if (c == -1 || d== -1) 856 return (-1); 857 nchar++; 858 if (c != d) { 859 repos(nchar); 860 return (0); 861 } 862 } while (c != '\n'); 863 } 864 repos(nchar); 865 return (1); 866 } 867 868 static void 869 repos(int nchar) 870 { 871 int i; 872 873 for (i = 0; i < 2; i++) 874 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 875 } 876 877 /* 878 * collect an editing script for later regurgitation 879 */ 880 static int 881 edit(struct diff *diff, int fdup, int j) 882 { 883 if (((fdup + 1) & eflag) == 0) 884 return (j); 885 j++; 886 overlap[j] = !fdup; 887 if (!fdup) 888 overlapcnt++; 889 de[j].old.from = diff->old.from; 890 de[j].old.to = diff->old.to; 891 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 892 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 893 return (j); 894 } 895 896 /* regurgitate */ 897 static int 898 edscript(int n) 899 { 900 int j, k; 901 char block[BUFSIZ+1]; 902 903 for (; n > 0; n--) { 904 if (!oflag || !overlap[n]) 905 prange(&de[n].old); 906 else 907 diff_output("%da\n=======\n", de[n].old.to -1); 908 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 909 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 910 j = k > BUFSIZ ? BUFSIZ : k; 911 if (fread(block, 1, j, fp[2]) != j) 912 return (-1); 913 block[j] = '\0'; 914 diff_output("%s", block); 915 } 916 917 if (!oflag || !overlap[n]) 918 diff_output(".\n"); 919 else { 920 diff_output("%s\n.\n", f3mark); 921 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 922 } 923 } 924 925 return (overlapcnt); 926 } 927 928 static void 929 increase(void) 930 { 931 size_t newsz, incr; 932 933 /* are the memset(3) calls needed? */ 934 newsz = szchanges == 0 ? 64 : 2 * szchanges; 935 incr = newsz - szchanges; 936 937 d13 = xrealloc(d13, newsz, sizeof(*d13)); 938 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 939 d23 = xrealloc(d23, newsz, sizeof(*d23)); 940 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 941 de = xrealloc(de, newsz, sizeof(*de)); 942 memset(de + szchanges, 0, incr * sizeof(*de)); 943 overlap = xrealloc(overlap, newsz, sizeof(*overlap)); 944 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 945 szchanges = newsz; 946 } 947