1 /* $OpenBSD: diff3.c,v 1.38 2015/11/02 16:45:21 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[PATH_MAX], f3mark[PATH_MAX]; /* 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 *get_line(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 buf_free(b2); 238 buf_free(b3); 239 buf_free(d1); 240 buf_free(d2); 241 242 (void)unlink(path1); 243 (void)unlink(path2); 244 (void)unlink(path3); 245 (void)unlink(dp13); 246 (void)unlink(dp23); 247 248 free(path1); 249 free(path2); 250 free(path3); 251 free(dp13); 252 free(dp23); 253 free(data); 254 free(patch); 255 256 return (diffb); 257 } 258 259 BUF * 260 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 261 { 262 int argc; 263 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 264 char *dp13, *dp23, *path1, *path2, *path3; 265 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 266 size_t dlen, plen; 267 u_char *data, *patch; 268 269 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 270 dp13 = dp23 = path1 = path2 = path3 = NULL; 271 data = patch = NULL; 272 273 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 274 oflag = 0; 275 276 rcsnum_tostr(rev1, r1, sizeof(r1)); 277 rcsnum_tostr(rev2, r2, sizeof(r2)); 278 279 if ((b1 = buf_load(workfile)) == NULL) 280 goto out; 281 282 if (!(flags & QUIET)) 283 (void)fprintf(stderr, "retrieving revision %s\n", r1); 284 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 285 goto out; 286 287 if (!(flags & QUIET)) 288 (void)fprintf(stderr, "retrieving revision %s\n", r2); 289 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 290 goto out; 291 292 d1 = buf_alloc(128); 293 d2 = buf_alloc(128); 294 diffb = buf_alloc(128); 295 296 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 297 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 298 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 299 300 buf_write_stmp(b1, path1); 301 buf_write_stmp(b2, path2); 302 buf_write_stmp(b3, path3); 303 304 buf_free(b2); 305 b2 = NULL; 306 307 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 308 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 309 buf_free(diffb); 310 diffb = NULL; 311 goto out; 312 } 313 314 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 315 buf_write_stmp(d1, dp13); 316 317 buf_free(d1); 318 d1 = NULL; 319 320 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 321 buf_write_stmp(d2, dp23); 322 323 buf_free(d2); 324 d2 = NULL; 325 326 argc = 0; 327 diffbuf = diffb; 328 argv[argc++] = dp13; 329 argv[argc++] = dp23; 330 argv[argc++] = path1; 331 argv[argc++] = path2; 332 argv[argc++] = path3; 333 334 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 335 if (diff3_conflicts < 0) { 336 buf_free(diffb); 337 diffb = NULL; 338 goto out; 339 } 340 341 plen = buf_len(diffb); 342 patch = buf_release(diffb); 343 dlen = buf_len(b1); 344 data = buf_release(b1); 345 346 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 347 goto out; 348 349 if (!(flags & QUIET) && diff3_conflicts != 0) 350 warnx("warning: overlaps or other problems during merge"); 351 352 out: 353 buf_free(b2); 354 buf_free(b3); 355 buf_free(d1); 356 buf_free(d2); 357 358 (void)unlink(path1); 359 (void)unlink(path2); 360 (void)unlink(path3); 361 (void)unlink(dp13); 362 (void)unlink(dp23); 363 364 free(path1); 365 free(path2); 366 free(path3); 367 free(dp13); 368 free(dp23); 369 free(data); 370 free(patch); 371 372 return (diffb); 373 } 374 375 static int 376 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 377 { 378 ssize_t m, n; 379 int i; 380 381 if (argc < 5) 382 return (-1); 383 384 if (oflag) { 385 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 386 if (i < 0 || i >= (int)sizeof(f1mark)) 387 errx(1, "diff3_internal: string truncated"); 388 389 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 390 if (i < 0 || i >= (int)sizeof(f3mark)) 391 errx(1, "diff3_internal: string truncated"); 392 } 393 394 increase(); 395 if ((m = readin(argv[0], &d13)) < 0) { 396 warn("%s", argv[0]); 397 return (-1); 398 } 399 if ((n = readin(argv[1], &d23)) < 0) { 400 warn("%s", argv[1]); 401 return (-1); 402 } 403 404 for (i = 0; i <= 2; i++) 405 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 406 warn("%s", argv[i + 2]); 407 return (-1); 408 } 409 410 return (merge(m, n)); 411 } 412 413 int 414 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 415 { 416 char op, *ep; 417 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 418 int start, end, i, lineno; 419 u_char tmp; 420 421 dlp = TAILQ_FIRST(&(dlines->l_lines)); 422 lp = TAILQ_FIRST(&(plines->l_lines)); 423 424 end = 0; 425 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 426 lp = TAILQ_NEXT(lp, l_list)) { 427 /* Skip blank lines */ 428 if (lp->l_len < 2) 429 continue; 430 431 /* NUL-terminate line buffer for strtol() safety. */ 432 tmp = lp->l_line[lp->l_len - 1]; 433 lp->l_line[lp->l_len - 1] = '\0'; 434 435 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 436 op = lp->l_line[lp->l_len - 2]; 437 start = (int)strtol(lp->l_line, &ep, 10); 438 439 /* Restore the last byte of the buffer */ 440 lp->l_line[lp->l_len - 1] = tmp; 441 442 if (op == 'a') { 443 if (start > dlines->l_nblines || 444 start < 0 || *ep != 'a') 445 errx(1, "ed_patch_lines"); 446 } else if (op == 'c') { 447 if (start > dlines->l_nblines || 448 start < 0 || (*ep != ',' && *ep != 'c')) 449 errx(1, "ed_patch_lines"); 450 451 if (*ep == ',') { 452 ep++; 453 end = (int)strtol(ep, &ep, 10); 454 if (end < 0 || *ep != 'c') 455 errx(1, "ed_patch_lines"); 456 } else { 457 end = start; 458 } 459 } 460 461 462 for (;;) { 463 if (dlp == NULL) 464 break; 465 if (dlp->l_lineno == start) 466 break; 467 if (dlp->l_lineno > start) { 468 dlp = TAILQ_PREV(dlp, tqh, l_list); 469 } else if (dlp->l_lineno < start) { 470 ndlp = TAILQ_NEXT(dlp, l_list); 471 if (ndlp->l_lineno > start) 472 break; 473 dlp = ndlp; 474 } 475 } 476 477 if (dlp == NULL) 478 errx(1, "ed_patch_lines"); 479 480 481 if (op == 'c') { 482 insert_after = TAILQ_PREV(dlp, tqh, l_list); 483 for (i = 0; i <= (end - start); i++) { 484 ndlp = TAILQ_NEXT(dlp, l_list); 485 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 486 dlp = ndlp; 487 } 488 dlp = insert_after; 489 } 490 491 if (op == 'a' || op == 'c') { 492 for (;;) { 493 ndlp = lp; 494 lp = TAILQ_NEXT(lp, l_list); 495 if (lp == NULL) 496 errx(1, "ed_patch_lines"); 497 498 if (!memcmp(lp->l_line, ".", 1)) 499 break; 500 501 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 502 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 503 lp, l_list); 504 dlp = lp; 505 506 lp->l_lineno = start; 507 lp = ndlp; 508 } 509 } 510 511 /* 512 * always resort lines as the markers might be put at the 513 * same line as we first started editing. 514 */ 515 lineno = 0; 516 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 517 sort->l_lineno = lineno++; 518 dlines->l_nblines = lineno - 1; 519 } 520 521 return (0); 522 } 523 524 /* 525 * Pick up the line numbers of all changes from one change file. 526 * (This puts the numbers in a vector, which is not strictly necessary, 527 * since the vector is processed in one sequential pass. 528 * The vector could be optimized out of existence) 529 */ 530 static ssize_t 531 readin(char *name, struct diff **dd) 532 { 533 int a, b, c, d; 534 char kind, *p; 535 size_t i; 536 537 fp[0] = fopen(name, "r"); 538 if (fp[0] == NULL) 539 return (-1); 540 for (i = 0; (p = getchange(fp[0])); i++) { 541 if (i >= szchanges - 1) 542 increase(); 543 a = b = number(&p); 544 if (*p == ',') { 545 p++; 546 b = number(&p); 547 } 548 kind = *p++; 549 c = d = number(&p); 550 if (*p==',') { 551 p++; 552 d = number(&p); 553 } 554 if (kind == 'a') 555 a++; 556 if (kind == 'd') 557 c++; 558 b++; 559 d++; 560 (*dd)[i].old.from = a; 561 (*dd)[i].old.to = b; 562 (*dd)[i].new.from = c; 563 (*dd)[i].new.to = d; 564 } 565 566 if (i) { 567 (*dd)[i].old.from = (*dd)[i-1].old.to; 568 (*dd)[i].new.from = (*dd)[i-1].new.to; 569 } 570 571 (void)fclose(fp[0]); 572 573 return (i); 574 } 575 576 static int 577 number(char **lc) 578 { 579 int nn; 580 581 nn = 0; 582 while (isdigit((unsigned char)(**lc))) 583 nn = nn*10 + *(*lc)++ - '0'; 584 585 return (nn); 586 } 587 588 static char * 589 getchange(FILE *b) 590 { 591 char *line; 592 593 while ((line = get_line(b, NULL))) { 594 if (isdigit((unsigned char)line[0])) 595 return (line); 596 } 597 598 return (NULL); 599 } 600 601 static char * 602 get_line(FILE *b, size_t *n) 603 { 604 char *cp; 605 size_t len; 606 static char *buf; 607 static size_t bufsize; 608 609 if ((cp = fgetln(b, &len)) == NULL) 610 return (NULL); 611 612 if (cp[len - 1] != '\n') 613 len++; 614 if (len + 1 > bufsize) { 615 do { 616 bufsize += 1024; 617 } while (len + 1 > bufsize); 618 buf = xreallocarray(buf, 1, bufsize); 619 } 620 memcpy(buf, cp, len - 1); 621 buf[len - 1] = '\n'; 622 buf[len] = '\0'; 623 if (n != NULL) 624 *n = len; 625 626 return (buf); 627 } 628 629 static int 630 merge(size_t m1, size_t m2) 631 { 632 struct diff *d1, *d2, *d3; 633 int dpl, j, t1, t2; 634 635 d1 = d13; 636 d2 = d23; 637 j = 0; 638 while ((t1 = (d1 < d13 + m1)) | (t2 = (d2 < d23 + m2))) { 639 if (debug) { 640 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 641 d1->old.from, d1->old.to, 642 d1->new.from, d1->new.to, 643 d2->old.from, d2->old.to, 644 d2->new.from, d2->new.to); 645 } 646 647 /* first file is different from others */ 648 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 649 /* stuff peculiar to 1st file */ 650 if (eflag==0) { 651 separate("1"); 652 change(1, &d1->old, 0); 653 keep(2, &d1->new); 654 change(3, &d1->new, 0); 655 } 656 d1++; 657 continue; 658 } 659 660 /* second file is different from others */ 661 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 662 if (eflag==0) { 663 separate("2"); 664 keep(1, &d2->new); 665 change(2, &d2->old, 0); 666 change(3, &d2->new, 0); 667 } 668 d2++; 669 continue; 670 } 671 672 /* 673 * Merge overlapping changes in first file 674 * this happens after extension (see below). 675 */ 676 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 677 d1[1].old.from = d1->old.from; 678 d1[1].new.from = d1->new.from; 679 d1++; 680 continue; 681 } 682 683 /* merge overlapping changes in second */ 684 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 685 d2[1].old.from = d2->old.from; 686 d2[1].new.from = d2->new.from; 687 d2++; 688 continue; 689 } 690 /* stuff peculiar to third file or different in all */ 691 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 692 dpl = duplicate(&d1->old,&d2->old); 693 if (dpl == -1) 694 return (-1); 695 696 /* 697 * dpl = 0 means all files differ 698 * dpl = 1 means files 1 and 2 identical 699 */ 700 if (eflag==0) { 701 separate(dpl ? "3" : ""); 702 change(1, &d1->old, dpl); 703 change(2, &d2->old, 0); 704 d3 = d1->old.to > d1->old.from ? d1 : d2; 705 change(3, &d3->new, 0); 706 } else 707 j = edit(d1, dpl, j); 708 d1++; 709 d2++; 710 continue; 711 } 712 713 /* 714 * Overlapping changes from file 1 and 2; extend changes 715 * appropriately to make them coincide. 716 */ 717 if (d1->new.from < d2->new.from) { 718 d2->old.from -= d2->new.from-d1->new.from; 719 d2->new.from = d1->new.from; 720 } else if (d2->new.from < d1->new.from) { 721 d1->old.from -= d1->new.from-d2->new.from; 722 d1->new.from = d2->new.from; 723 } 724 if (d1->new.to > d2->new.to) { 725 d2->old.to += d1->new.to - d2->new.to; 726 d2->new.to = d1->new.to; 727 } else if (d2->new.to > d1->new.to) { 728 d1->old.to += d2->new.to - d1->new.to; 729 d1->new.to = d2->new.to; 730 } 731 } 732 733 return (edscript(j)); 734 } 735 736 static void 737 separate(const char *s) 738 { 739 diff_output("====%s\n", s); 740 } 741 742 /* 743 * The range of lines rold.from thru rold.to in file i is to be changed. 744 * It is to be printed only if it does not duplicate something to be 745 * printed later. 746 */ 747 static void 748 change(int i, struct range *rold, int fdup) 749 { 750 diff_output("%d:", i); 751 last[i] = rold->to; 752 prange(rold); 753 if (fdup || debug) 754 return; 755 i--; 756 (void)skip(i, rold->from, NULL); 757 (void)skip(i, rold->to, " "); 758 } 759 760 /* 761 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 762 */ 763 static void 764 prange(struct range *rold) 765 { 766 if (rold->to <= rold->from) 767 diff_output("%da\n", rold->from - 1); 768 else { 769 diff_output("%d", rold->from); 770 if (rold->to > rold->from+1) 771 diff_output(",%d", rold->to - 1); 772 diff_output("c\n"); 773 } 774 } 775 776 /* 777 * No difference was reported by diff between file 1 (or 2) and file 3, 778 * and an artificial dummy difference (trange) must be ginned up to 779 * correspond to the change reported in the other file. 780 */ 781 static void 782 keep(int i, struct range *rnew) 783 { 784 int delta; 785 struct range trange; 786 787 delta = last[3] - last[i]; 788 trange.from = rnew->from - delta; 789 trange.to = rnew->to - delta; 790 change(i, &trange, 1); 791 } 792 793 /* 794 * skip to just before line number from in file "i". If "pr" is non-NULL, 795 * print all skipped stuff with string pr as a prefix. 796 */ 797 static int 798 skip(int i, int from, char *pr) 799 { 800 size_t j, n; 801 char *line; 802 803 for (n = 0; cline[i] < from - 1; n += j) { 804 if ((line = get_line(fp[i], &j)) == NULL) 805 return (-1); 806 if (pr != NULL) 807 diff_output("%s%s", pr, line); 808 cline[i]++; 809 } 810 return ((int) n); 811 } 812 813 /* 814 * Return 1 or 0 according as the old range (in file 1) contains exactly 815 * the same data as the new range (in file 2). 816 */ 817 static int 818 duplicate(struct range *r1, struct range *r2) 819 { 820 int c,d; 821 int nchar; 822 int nline; 823 824 if (r1->to-r1->from != r2->to-r2->from) 825 return (0); 826 (void)skip(0, r1->from, NULL); 827 (void)skip(1, r2->from, NULL); 828 nchar = 0; 829 for (nline=0; nline < r1->to - r1->from; nline++) { 830 do { 831 c = getc(fp[0]); 832 d = getc(fp[1]); 833 if (c == -1 || d== -1) 834 return (-1); 835 nchar++; 836 if (c != d) { 837 repos(nchar); 838 return (0); 839 } 840 } while (c != '\n'); 841 } 842 repos(nchar); 843 return (1); 844 } 845 846 static void 847 repos(int nchar) 848 { 849 int i; 850 851 for (i = 0; i < 2; i++) 852 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 853 } 854 855 /* 856 * collect an editing script for later regurgitation 857 */ 858 static int 859 edit(struct diff *diff, int fdup, int j) 860 { 861 if (((fdup + 1) & eflag) == 0) 862 return (j); 863 j++; 864 overlap[j] = !fdup; 865 if (!fdup) 866 overlapcnt++; 867 de[j].old.from = diff->old.from; 868 de[j].old.to = diff->old.to; 869 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 870 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 871 return (j); 872 } 873 874 /* regurgitate */ 875 static int 876 edscript(int n) 877 { 878 int j, k; 879 char block[BUFSIZ+1]; 880 881 for (; n > 0; n--) { 882 if (!oflag || !overlap[n]) 883 prange(&de[n].old); 884 else 885 diff_output("%da\n=======\n", de[n].old.to -1); 886 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 887 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 888 j = k > BUFSIZ ? BUFSIZ : k; 889 if (fread(block, 1, j, fp[2]) != j) 890 return (-1); 891 block[j] = '\0'; 892 diff_output("%s", block); 893 } 894 895 if (!oflag || !overlap[n]) 896 diff_output(".\n"); 897 else { 898 diff_output("%s\n.\n", f3mark); 899 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 900 } 901 } 902 903 return (overlapcnt); 904 } 905 906 static void 907 increase(void) 908 { 909 size_t newsz, incr; 910 911 /* are the memset(3) calls needed? */ 912 newsz = szchanges == 0 ? 64 : 2 * szchanges; 913 incr = newsz - szchanges; 914 915 d13 = xreallocarray(d13, newsz, sizeof(*d13)); 916 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 917 d23 = xreallocarray(d23, newsz, sizeof(*d23)); 918 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 919 de = xreallocarray(de, newsz, sizeof(*de)); 920 memset(de + szchanges, 0, incr * sizeof(*de)); 921 overlap = xreallocarray(overlap, newsz, sizeof(*overlap)); 922 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 923 szchanges = newsz; 924 } 925