1 /* $OpenBSD: diff3.c,v 1.44 2020/06/26 07:28:46 stsp 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 <time.h> 73 #include <unistd.h> 74 75 #include "diff.h" 76 #include "rcsprog.h" 77 78 /* diff3 - 3-way differential file comparison */ 79 80 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 81 * 82 * d13 = diff report on f1 vs f3 83 * d23 = diff report on f2 vs f3 84 * f1, f2, f3 the 3 files 85 * if changes in f1 overlap with changes in f3, m1 and m3 are used 86 * to mark the overlaps; otherwise, the file names f1 and f3 are used 87 * (only for options E and X). 88 */ 89 90 /* 91 * "from" is first in range of changed lines; "to" is last+1 92 * from=to=line after point of insertion for added lines. 93 */ 94 struct range { 95 int from; 96 int to; 97 }; 98 99 struct diff { 100 struct range old; 101 struct range new; 102 }; 103 104 static size_t szchanges; 105 106 static struct diff *d13; 107 static struct diff *d23; 108 109 /* 110 * "de" is used to gather editing scripts. These are later spewed out in 111 * reverse order. Its first element must be all zero, the "new" component 112 * of "de" contains line positions or byte positions depending on when you 113 * look (!?). Array overlap indicates which sections in "de" correspond to 114 * lines that are different in all three files. 115 */ 116 static struct diff *de; 117 static char *overlap; 118 static int overlapcnt = 0; 119 static FILE *fp[3]; 120 static int cline[3]; /* # of the last-read line in each file (0-2) */ 121 122 /* 123 * the latest known correspondence between line numbers of the 3 files 124 * is stored in last[1-3]; 125 */ 126 static int last[4]; 127 static int eflag = 3; /* default -E for compatibility with former RCS */ 128 static int oflag = 1; /* default -E for compatibility with former RCS */ 129 static int debug = 0; 130 static char f1mark[PATH_MAX], f3mark[PATH_MAX]; /* markers for -E and -X */ 131 132 static int duplicate(struct range *, struct range *); 133 static int edit(struct diff *, int, int); 134 static char *getchange(FILE *); 135 static char *get_line(FILE *, size_t *); 136 static int number(char **); 137 static ssize_t readin(char *, struct diff **); 138 static int skip(int, int, char *); 139 static int edscript(int); 140 static int merge(size_t, size_t); 141 static void change(int, struct range *, int); 142 static void keep(int, struct range *); 143 static void prange(struct range *); 144 static void repos(int); 145 static void separate(const char *); 146 static void increase(void); 147 static int diff3_internal(int, char **, const char *, const char *); 148 149 int diff3_conflicts = 0; 150 151 /* 152 * For merge(1). 153 */ 154 BUF * 155 merge_diff3(char **av, int flags) 156 { 157 int argc; 158 char *argv[5], *dp13, *dp23, *path1, *path2, *path3; 159 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 160 u_char *data, *patch; 161 size_t dlen, plen; 162 163 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 164 dp13 = dp23 = path1 = path2 = path3 = NULL; 165 data = patch = NULL; 166 167 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 168 oflag = 0; 169 170 if ((b1 = buf_load(av[0])) == NULL) 171 goto out; 172 if ((b2 = buf_load(av[1])) == NULL) 173 goto out; 174 if ((b3 = buf_load(av[2])) == NULL) 175 goto out; 176 177 d1 = buf_alloc(128); 178 d2 = buf_alloc(128); 179 diffb = buf_alloc(128); 180 181 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 182 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 183 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 184 185 buf_write_stmp(b1, path1); 186 buf_write_stmp(b2, path2); 187 buf_write_stmp(b3, path3); 188 189 buf_free(b2); 190 b2 = NULL; 191 192 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 193 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 194 buf_free(diffb); 195 diffb = NULL; 196 goto out; 197 } 198 199 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 200 buf_write_stmp(d1, dp13); 201 202 buf_free(d1); 203 d1 = NULL; 204 205 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 206 buf_write_stmp(d2, dp23); 207 208 buf_free(d2); 209 d2 = NULL; 210 211 argc = 0; 212 diffbuf = diffb; 213 argv[argc++] = dp13; 214 argv[argc++] = dp23; 215 argv[argc++] = path1; 216 argv[argc++] = path2; 217 argv[argc++] = path3; 218 219 diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]); 220 if (diff3_conflicts < 0) { 221 buf_free(diffb); 222 diffb = NULL; 223 goto out; 224 } 225 226 plen = buf_len(diffb); 227 patch = buf_release(diffb); 228 dlen = buf_len(b1); 229 data = buf_release(b1); 230 231 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 232 goto out; 233 234 if (!(flags & QUIET) && diff3_conflicts != 0) 235 warnx("warning: overlaps or other problems during merge"); 236 237 out: 238 buf_free(b2); 239 buf_free(b3); 240 buf_free(d1); 241 buf_free(d2); 242 243 (void)unlink(path1); 244 (void)unlink(path2); 245 (void)unlink(path3); 246 (void)unlink(dp13); 247 (void)unlink(dp23); 248 249 free(path1); 250 free(path2); 251 free(path3); 252 free(dp13); 253 free(dp23); 254 free(data); 255 free(patch); 256 257 return (diffb); 258 } 259 260 BUF * 261 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 262 { 263 int argc; 264 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 265 char *dp13, *dp23, *path1, *path2, *path3; 266 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 267 size_t dlen, plen; 268 u_char *data, *patch; 269 270 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 271 dp13 = dp23 = path1 = path2 = path3 = NULL; 272 data = patch = NULL; 273 274 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 275 oflag = 0; 276 277 rcsnum_tostr(rev1, r1, sizeof(r1)); 278 rcsnum_tostr(rev2, r2, sizeof(r2)); 279 280 if ((b1 = buf_load(workfile)) == NULL) 281 goto out; 282 283 if (!(flags & QUIET)) 284 (void)fprintf(stderr, "retrieving revision %s\n", r1); 285 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 286 goto out; 287 288 if (!(flags & QUIET)) 289 (void)fprintf(stderr, "retrieving revision %s\n", r2); 290 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 291 goto out; 292 293 d1 = buf_alloc(128); 294 d2 = buf_alloc(128); 295 diffb = buf_alloc(128); 296 297 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 298 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 299 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 300 301 buf_write_stmp(b1, path1); 302 buf_write_stmp(b2, path2); 303 buf_write_stmp(b3, path3); 304 305 buf_free(b2); 306 b2 = NULL; 307 308 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 309 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 310 buf_free(diffb); 311 diffb = NULL; 312 goto out; 313 } 314 315 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 316 buf_write_stmp(d1, dp13); 317 318 buf_free(d1); 319 d1 = NULL; 320 321 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 322 buf_write_stmp(d2, dp23); 323 324 buf_free(d2); 325 d2 = NULL; 326 327 argc = 0; 328 diffbuf = diffb; 329 argv[argc++] = dp13; 330 argv[argc++] = dp23; 331 argv[argc++] = path1; 332 argv[argc++] = path2; 333 argv[argc++] = path3; 334 335 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 336 if (diff3_conflicts < 0) { 337 buf_free(diffb); 338 diffb = NULL; 339 goto out; 340 } 341 342 plen = buf_len(diffb); 343 patch = buf_release(diffb); 344 dlen = buf_len(b1); 345 data = buf_release(b1); 346 347 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 348 goto out; 349 350 if (!(flags & QUIET) && diff3_conflicts != 0) 351 warnx("warning: overlaps or other problems during merge"); 352 353 out: 354 buf_free(b2); 355 buf_free(b3); 356 buf_free(d1); 357 buf_free(d2); 358 359 (void)unlink(path1); 360 (void)unlink(path2); 361 (void)unlink(path3); 362 (void)unlink(dp13); 363 (void)unlink(dp23); 364 365 free(path1); 366 free(path2); 367 free(path3); 368 free(dp13); 369 free(dp23); 370 free(data); 371 free(patch); 372 373 return (diffb); 374 } 375 376 static int 377 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 378 { 379 ssize_t m, n; 380 int i; 381 382 if (argc < 5) 383 return (-1); 384 385 if (oflag) { 386 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 387 if (i < 0 || i >= (int)sizeof(f1mark)) 388 errx(1, "diff3_internal: string truncated"); 389 390 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 391 if (i < 0 || i >= (int)sizeof(f3mark)) 392 errx(1, "diff3_internal: string truncated"); 393 } 394 395 increase(); 396 if ((m = readin(argv[0], &d13)) < 0) { 397 warn("%s", argv[0]); 398 return (-1); 399 } 400 if ((n = readin(argv[1], &d23)) < 0) { 401 warn("%s", argv[1]); 402 return (-1); 403 } 404 405 for (i = 0; i <= 2; i++) 406 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 407 warn("%s", argv[i + 2]); 408 return (-1); 409 } 410 411 return (merge(m, n)); 412 } 413 414 int 415 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 416 { 417 char op, *ep; 418 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 419 int start, end, i, lineno; 420 u_char tmp; 421 422 dlp = TAILQ_FIRST(&(dlines->l_lines)); 423 lp = TAILQ_FIRST(&(plines->l_lines)); 424 425 end = 0; 426 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 427 lp = TAILQ_NEXT(lp, l_list)) { 428 /* Skip blank lines */ 429 if (lp->l_len < 2) 430 continue; 431 432 /* NUL-terminate line buffer for strtol() safety. */ 433 tmp = lp->l_line[lp->l_len - 1]; 434 lp->l_line[lp->l_len - 1] = '\0'; 435 436 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 437 op = lp->l_line[lp->l_len - 2]; 438 start = (int)strtol(lp->l_line, &ep, 10); 439 440 /* Restore the last byte of the buffer */ 441 lp->l_line[lp->l_len - 1] = tmp; 442 443 if (op == 'a') { 444 if (start > dlines->l_nblines || 445 start < 0 || *ep != 'a') 446 errx(1, "ed_patch_lines"); 447 } else if (op == 'c') { 448 if (start > dlines->l_nblines || 449 start < 0 || (*ep != ',' && *ep != 'c')) 450 errx(1, "ed_patch_lines"); 451 452 if (*ep == ',') { 453 ep++; 454 end = (int)strtol(ep, &ep, 10); 455 if (end < 0 || *ep != 'c') 456 errx(1, "ed_patch_lines"); 457 } else { 458 end = start; 459 } 460 } 461 462 463 for (;;) { 464 if (dlp == NULL) 465 break; 466 if (dlp->l_lineno == start) 467 break; 468 if (dlp->l_lineno > start) { 469 dlp = TAILQ_PREV(dlp, tqh, l_list); 470 } else if (dlp->l_lineno < start) { 471 ndlp = TAILQ_NEXT(dlp, l_list); 472 if (ndlp->l_lineno > start) 473 break; 474 dlp = ndlp; 475 } 476 } 477 478 if (dlp == NULL) 479 errx(1, "ed_patch_lines"); 480 481 482 if (op == 'c') { 483 insert_after = TAILQ_PREV(dlp, tqh, l_list); 484 for (i = 0; i <= (end - start); i++) { 485 ndlp = TAILQ_NEXT(dlp, l_list); 486 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 487 dlp = ndlp; 488 } 489 dlp = insert_after; 490 } 491 492 if (op == 'a' || op == 'c') { 493 for (;;) { 494 ndlp = lp; 495 lp = TAILQ_NEXT(lp, l_list); 496 if (lp == NULL) 497 errx(1, "ed_patch_lines"); 498 499 if (lp->l_len == 2 && 500 lp->l_line[0] == '.' && 501 lp->l_line[1] == '\n') 502 break; 503 504 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 505 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 506 lp, l_list); 507 dlp = lp; 508 509 lp->l_lineno = start; 510 lp = ndlp; 511 } 512 } 513 514 /* 515 * always resort lines as the markers might be put at the 516 * same line as we first started editing. 517 */ 518 lineno = 0; 519 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 520 sort->l_lineno = lineno++; 521 dlines->l_nblines = lineno - 1; 522 } 523 524 return (0); 525 } 526 527 /* 528 * Pick up the line numbers of all changes from one change file. 529 * (This puts the numbers in a vector, which is not strictly necessary, 530 * since the vector is processed in one sequential pass. 531 * The vector could be optimized out of existence) 532 */ 533 static ssize_t 534 readin(char *name, struct diff **dd) 535 { 536 int a, b, c, d; 537 char kind, *p; 538 size_t i; 539 540 fp[0] = fopen(name, "r"); 541 if (fp[0] == NULL) 542 return (-1); 543 for (i = 0; (p = getchange(fp[0])); i++) { 544 if (i >= szchanges - 1) 545 increase(); 546 a = b = number(&p); 547 if (*p == ',') { 548 p++; 549 b = number(&p); 550 } 551 kind = *p++; 552 c = d = number(&p); 553 if (*p==',') { 554 p++; 555 d = number(&p); 556 } 557 if (kind == 'a') 558 a++; 559 if (kind == 'd') 560 c++; 561 b++; 562 d++; 563 (*dd)[i].old.from = a; 564 (*dd)[i].old.to = b; 565 (*dd)[i].new.from = c; 566 (*dd)[i].new.to = d; 567 } 568 569 if (i) { 570 (*dd)[i].old.from = (*dd)[i-1].old.to; 571 (*dd)[i].new.from = (*dd)[i-1].new.to; 572 } 573 574 (void)fclose(fp[0]); 575 576 return (i); 577 } 578 579 static int 580 number(char **lc) 581 { 582 int nn; 583 584 nn = 0; 585 while (isdigit((unsigned char)(**lc))) 586 nn = nn*10 + *(*lc)++ - '0'; 587 588 return (nn); 589 } 590 591 static char * 592 getchange(FILE *b) 593 { 594 char *line; 595 596 while ((line = get_line(b, NULL))) { 597 if (isdigit((unsigned char)line[0])) 598 return (line); 599 } 600 601 return (NULL); 602 } 603 604 static char * 605 get_line(FILE *b, size_t *n) 606 { 607 char *cp; 608 size_t len; 609 static char *buf; 610 static size_t bufsize; 611 612 if ((cp = fgetln(b, &len)) == NULL) 613 return (NULL); 614 615 if (cp[len - 1] != '\n') 616 len++; 617 if (len + 1 > bufsize) { 618 do { 619 bufsize += 1024; 620 } while (len + 1 > bufsize); 621 buf = xreallocarray(buf, 1, bufsize); 622 } 623 memcpy(buf, cp, len - 1); 624 buf[len - 1] = '\n'; 625 buf[len] = '\0'; 626 if (n != NULL) 627 *n = len; 628 629 return (buf); 630 } 631 632 static int 633 merge(size_t m1, size_t m2) 634 { 635 struct diff *d1, *d2, *d3; 636 int dpl, j, t1, t2; 637 638 d1 = d13; 639 d2 = d23; 640 j = 0; 641 for (;;) { 642 t1 = (d1 < d13 + m1); 643 t2 = (d2 < d23 + m2); 644 if (!t1 && !t2) 645 break; 646 647 if (debug) { 648 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 649 d1->old.from, d1->old.to, 650 d1->new.from, d1->new.to, 651 d2->old.from, d2->old.to, 652 d2->new.from, d2->new.to); 653 } 654 655 /* first file is different from others */ 656 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 657 /* stuff peculiar to 1st file */ 658 if (eflag==0) { 659 separate("1"); 660 change(1, &d1->old, 0); 661 keep(2, &d1->new); 662 change(3, &d1->new, 0); 663 } 664 d1++; 665 continue; 666 } 667 668 /* second file is different from others */ 669 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 670 if (eflag==0) { 671 separate("2"); 672 keep(1, &d2->new); 673 change(2, &d2->old, 0); 674 change(3, &d2->new, 0); 675 } 676 d2++; 677 continue; 678 } 679 680 /* 681 * Merge overlapping changes in first file 682 * this happens after extension (see below). 683 */ 684 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 685 d1[1].old.from = d1->old.from; 686 d1[1].new.from = d1->new.from; 687 d1++; 688 continue; 689 } 690 691 /* merge overlapping changes in second */ 692 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 693 d2[1].old.from = d2->old.from; 694 d2[1].new.from = d2->new.from; 695 d2++; 696 continue; 697 } 698 /* stuff peculiar to third file or different in all */ 699 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 700 dpl = duplicate(&d1->old,&d2->old); 701 if (dpl == -1) 702 return (-1); 703 704 /* 705 * dpl = 0 means all files differ 706 * dpl = 1 means files 1 and 2 identical 707 */ 708 if (eflag==0) { 709 separate(dpl ? "3" : ""); 710 change(1, &d1->old, dpl); 711 change(2, &d2->old, 0); 712 d3 = d1->old.to > d1->old.from ? d1 : d2; 713 change(3, &d3->new, 0); 714 } else 715 j = edit(d1, dpl, j); 716 d1++; 717 d2++; 718 continue; 719 } 720 721 /* 722 * Overlapping changes from file 1 and 2; extend changes 723 * appropriately to make them coincide. 724 */ 725 if (d1->new.from < d2->new.from) { 726 d2->old.from -= d2->new.from-d1->new.from; 727 d2->new.from = d1->new.from; 728 } else if (d2->new.from < d1->new.from) { 729 d1->old.from -= d1->new.from-d2->new.from; 730 d1->new.from = d2->new.from; 731 } 732 if (d1->new.to > d2->new.to) { 733 d2->old.to += d1->new.to - d2->new.to; 734 d2->new.to = d1->new.to; 735 } else if (d2->new.to > d1->new.to) { 736 d1->old.to += d2->new.to - d1->new.to; 737 d1->new.to = d2->new.to; 738 } 739 } 740 741 return (edscript(j)); 742 } 743 744 static void 745 separate(const char *s) 746 { 747 diff_output("====%s\n", s); 748 } 749 750 /* 751 * The range of lines rold.from thru rold.to in file i is to be changed. 752 * It is to be printed only if it does not duplicate something to be 753 * printed later. 754 */ 755 static void 756 change(int i, struct range *rold, int fdup) 757 { 758 diff_output("%d:", i); 759 last[i] = rold->to; 760 prange(rold); 761 if (fdup || debug) 762 return; 763 i--; 764 (void)skip(i, rold->from, NULL); 765 (void)skip(i, rold->to, " "); 766 } 767 768 /* 769 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 770 */ 771 static void 772 prange(struct range *rold) 773 { 774 if (rold->to <= rold->from) 775 diff_output("%da\n", rold->from - 1); 776 else { 777 diff_output("%d", rold->from); 778 if (rold->to > rold->from+1) 779 diff_output(",%d", rold->to - 1); 780 diff_output("c\n"); 781 } 782 } 783 784 /* 785 * No difference was reported by diff between file 1 (or 2) and file 3, 786 * and an artificial dummy difference (trange) must be ginned up to 787 * correspond to the change reported in the other file. 788 */ 789 static void 790 keep(int i, struct range *rnew) 791 { 792 int delta; 793 struct range trange; 794 795 delta = last[3] - last[i]; 796 trange.from = rnew->from - delta; 797 trange.to = rnew->to - delta; 798 change(i, &trange, 1); 799 } 800 801 /* 802 * skip to just before line number from in file "i". If "pr" is non-NULL, 803 * print all skipped stuff with string pr as a prefix. 804 */ 805 static int 806 skip(int i, int from, char *pr) 807 { 808 size_t j, n; 809 char *line; 810 811 for (n = 0; cline[i] < from - 1; n += j) { 812 if ((line = get_line(fp[i], &j)) == NULL) 813 return (-1); 814 if (pr != NULL) 815 diff_output("%s%s", pr, line); 816 cline[i]++; 817 } 818 return ((int) n); 819 } 820 821 /* 822 * Return 1 or 0 according as the old range (in file 1) contains exactly 823 * the same data as the new range (in file 2). 824 */ 825 static int 826 duplicate(struct range *r1, struct range *r2) 827 { 828 int c,d; 829 int nchar; 830 int nline; 831 832 if (r1->to-r1->from != r2->to-r2->from) 833 return (0); 834 (void)skip(0, r1->from, NULL); 835 (void)skip(1, r2->from, NULL); 836 nchar = 0; 837 for (nline=0; nline < r1->to - r1->from; nline++) { 838 do { 839 c = getc(fp[0]); 840 d = getc(fp[1]); 841 if (c == -1 || d== -1) 842 return (-1); 843 nchar++; 844 if (c != d) { 845 repos(nchar); 846 return (0); 847 } 848 } while (c != '\n'); 849 } 850 repos(nchar); 851 return (1); 852 } 853 854 static void 855 repos(int nchar) 856 { 857 int i; 858 859 for (i = 0; i < 2; i++) 860 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 861 } 862 863 /* 864 * collect an editing script for later regurgitation 865 */ 866 static int 867 edit(struct diff *diff, int fdup, int j) 868 { 869 if (((fdup + 1) & eflag) == 0) 870 return (j); 871 j++; 872 overlap[j] = !fdup; 873 if (!fdup) 874 overlapcnt++; 875 de[j].old.from = diff->old.from; 876 de[j].old.to = diff->old.to; 877 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 878 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 879 return (j); 880 } 881 882 /* regurgitate */ 883 static int 884 edscript(int n) 885 { 886 int j, k; 887 char block[BUFSIZ+1]; 888 889 for (; n > 0; n--) { 890 if (!oflag || !overlap[n]) 891 prange(&de[n].old); 892 else 893 diff_output("%da\n=======\n", de[n].old.to -1); 894 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 895 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 896 size_t r; 897 j = k > BUFSIZ ? BUFSIZ : k; 898 r = fread(block, 1, j, fp[2]); 899 if (r == 0) { 900 if (feof(fp[2])) 901 break; 902 return -1; 903 } 904 if (r != (size_t)j) 905 j = r; 906 block[j] = '\0'; 907 diff_output("%s", block); 908 } 909 910 if (!oflag || !overlap[n]) 911 diff_output(".\n"); 912 else { 913 diff_output("%s\n.\n", f3mark); 914 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 915 } 916 } 917 918 return (overlapcnt); 919 } 920 921 static void 922 increase(void) 923 { 924 size_t newsz, incr; 925 926 /* are the memset(3) calls needed? */ 927 newsz = szchanges == 0 ? 64 : 2 * szchanges; 928 incr = newsz - szchanges; 929 930 d13 = xreallocarray(d13, newsz, sizeof(*d13)); 931 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 932 d23 = xreallocarray(d23, newsz, sizeof(*d23)); 933 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 934 de = xreallocarray(de, newsz, sizeof(*de)); 935 memset(de + szchanges, 0, incr * sizeof(*de)); 936 overlap = xreallocarray(overlap, newsz, sizeof(*overlap)); 937 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 938 szchanges = newsz; 939 } 940