1 /* $OpenBSD: diff3.c,v 1.36 2015/06/13 20:15:21 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 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 free(path1); 253 free(path2); 254 free(path3); 255 free(dp13); 256 free(dp23); 257 free(data); 258 free(patch); 259 260 return (diffb); 261 } 262 263 BUF * 264 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 265 { 266 int argc; 267 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 268 char *dp13, *dp23, *path1, *path2, *path3; 269 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 270 size_t dlen, plen; 271 u_char *data, *patch; 272 273 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 274 dp13 = dp23 = path1 = path2 = path3 = NULL; 275 data = patch = NULL; 276 277 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 278 oflag = 0; 279 280 rcsnum_tostr(rev1, r1, sizeof(r1)); 281 rcsnum_tostr(rev2, r2, sizeof(r2)); 282 283 if ((b1 = buf_load(workfile)) == NULL) 284 goto out; 285 286 if (!(flags & QUIET)) 287 (void)fprintf(stderr, "retrieving revision %s\n", r1); 288 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 289 goto out; 290 291 if (!(flags & QUIET)) 292 (void)fprintf(stderr, "retrieving revision %s\n", r2); 293 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 294 goto out; 295 296 d1 = buf_alloc(128); 297 d2 = buf_alloc(128); 298 diffb = buf_alloc(128); 299 300 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 301 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 302 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 303 304 buf_write_stmp(b1, path1); 305 buf_write_stmp(b2, path2); 306 buf_write_stmp(b3, path3); 307 308 buf_free(b2); 309 b2 = NULL; 310 311 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 312 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 313 buf_free(diffb); 314 diffb = NULL; 315 goto out; 316 } 317 318 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 319 buf_write_stmp(d1, dp13); 320 321 buf_free(d1); 322 d1 = NULL; 323 324 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 325 buf_write_stmp(d2, dp23); 326 327 buf_free(d2); 328 d2 = NULL; 329 330 argc = 0; 331 diffbuf = diffb; 332 argv[argc++] = dp13; 333 argv[argc++] = dp23; 334 argv[argc++] = path1; 335 argv[argc++] = path2; 336 argv[argc++] = path3; 337 338 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 339 if (diff3_conflicts < 0) { 340 buf_free(diffb); 341 diffb = NULL; 342 goto out; 343 } 344 345 plen = buf_len(diffb); 346 patch = buf_release(diffb); 347 dlen = buf_len(b1); 348 data = buf_release(b1); 349 350 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 351 goto out; 352 353 if (!(flags & QUIET) && diff3_conflicts != 0) 354 warnx("warning: overlaps or other problems during merge"); 355 356 out: 357 if (b2 != NULL) 358 buf_free(b2); 359 if (b3 != NULL) 360 buf_free(b3); 361 if (d1 != NULL) 362 buf_free(d1); 363 if (d2 != NULL) 364 buf_free(d2); 365 366 (void)unlink(path1); 367 (void)unlink(path2); 368 (void)unlink(path3); 369 (void)unlink(dp13); 370 (void)unlink(dp23); 371 372 free(path1); 373 free(path2); 374 free(path3); 375 free(dp13); 376 free(dp23); 377 free(data); 378 free(patch); 379 380 return (diffb); 381 } 382 383 static int 384 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 385 { 386 ssize_t m, n; 387 int i; 388 389 if (argc < 5) 390 return (-1); 391 392 if (oflag) { 393 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 394 if (i < 0 || i >= (int)sizeof(f1mark)) 395 errx(1, "diff3_internal: string truncated"); 396 397 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 398 if (i < 0 || i >= (int)sizeof(f3mark)) 399 errx(1, "diff3_internal: string truncated"); 400 } 401 402 increase(); 403 if ((m = readin(argv[0], &d13)) < 0) { 404 warn("%s", argv[0]); 405 return (-1); 406 } 407 if ((n = readin(argv[1], &d23)) < 0) { 408 warn("%s", argv[1]); 409 return (-1); 410 } 411 412 for (i = 0; i <= 2; i++) 413 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 414 warn("%s", argv[i + 2]); 415 return (-1); 416 } 417 418 return (merge(m, n)); 419 } 420 421 int 422 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 423 { 424 char op, *ep; 425 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 426 int start, end, i, lineno; 427 u_char tmp; 428 429 dlp = TAILQ_FIRST(&(dlines->l_lines)); 430 lp = TAILQ_FIRST(&(plines->l_lines)); 431 432 end = 0; 433 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 434 lp = TAILQ_NEXT(lp, l_list)) { 435 /* Skip blank lines */ 436 if (lp->l_len < 2) 437 continue; 438 439 /* NUL-terminate line buffer for strtol() safety. */ 440 tmp = lp->l_line[lp->l_len - 1]; 441 lp->l_line[lp->l_len - 1] = '\0'; 442 443 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 444 op = lp->l_line[lp->l_len - 2]; 445 start = (int)strtol(lp->l_line, &ep, 10); 446 447 /* Restore the last byte of the buffer */ 448 lp->l_line[lp->l_len - 1] = tmp; 449 450 if (op == 'a') { 451 if (start > dlines->l_nblines || 452 start < 0 || *ep != 'a') 453 errx(1, "ed_patch_lines"); 454 } else if (op == 'c') { 455 if (start > dlines->l_nblines || 456 start < 0 || (*ep != ',' && *ep != 'c')) 457 errx(1, "ed_patch_lines"); 458 459 if (*ep == ',') { 460 ep++; 461 end = (int)strtol(ep, &ep, 10); 462 if (end < 0 || *ep != 'c') 463 errx(1, "ed_patch_lines"); 464 } else { 465 end = start; 466 } 467 } 468 469 470 for (;;) { 471 if (dlp == NULL) 472 break; 473 if (dlp->l_lineno == start) 474 break; 475 if (dlp->l_lineno > start) { 476 dlp = TAILQ_PREV(dlp, tqh, l_list); 477 } else if (dlp->l_lineno < start) { 478 ndlp = TAILQ_NEXT(dlp, l_list); 479 if (ndlp->l_lineno > start) 480 break; 481 dlp = ndlp; 482 } 483 } 484 485 if (dlp == NULL) 486 errx(1, "ed_patch_lines"); 487 488 489 if (op == 'c') { 490 insert_after = TAILQ_PREV(dlp, tqh, l_list); 491 for (i = 0; i <= (end - start); i++) { 492 ndlp = TAILQ_NEXT(dlp, l_list); 493 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 494 dlp = ndlp; 495 } 496 dlp = insert_after; 497 } 498 499 if (op == 'a' || op == 'c') { 500 for (;;) { 501 ndlp = lp; 502 lp = TAILQ_NEXT(lp, l_list); 503 if (lp == NULL) 504 errx(1, "ed_patch_lines"); 505 506 if (!memcmp(lp->l_line, ".", 1)) 507 break; 508 509 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 510 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 511 lp, l_list); 512 dlp = lp; 513 514 lp->l_lineno = start; 515 lp = ndlp; 516 } 517 } 518 519 /* 520 * always resort lines as the markers might be put at the 521 * same line as we first started editing. 522 */ 523 lineno = 0; 524 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 525 sort->l_lineno = lineno++; 526 dlines->l_nblines = lineno - 1; 527 } 528 529 return (0); 530 } 531 532 /* 533 * Pick up the line numbers of all changes from one change file. 534 * (This puts the numbers in a vector, which is not strictly necessary, 535 * since the vector is processed in one sequential pass. 536 * The vector could be optimized out of existence) 537 */ 538 static ssize_t 539 readin(char *name, struct diff **dd) 540 { 541 int a, b, c, d; 542 char kind, *p; 543 size_t i; 544 545 fp[0] = fopen(name, "r"); 546 if (fp[0] == NULL) 547 return (-1); 548 for (i = 0; (p = getchange(fp[0])); i++) { 549 if (i >= szchanges - 1) 550 increase(); 551 a = b = number(&p); 552 if (*p == ',') { 553 p++; 554 b = number(&p); 555 } 556 kind = *p++; 557 c = d = number(&p); 558 if (*p==',') { 559 p++; 560 d = number(&p); 561 } 562 if (kind == 'a') 563 a++; 564 if (kind == 'd') 565 c++; 566 b++; 567 d++; 568 (*dd)[i].old.from = a; 569 (*dd)[i].old.to = b; 570 (*dd)[i].new.from = c; 571 (*dd)[i].new.to = d; 572 } 573 574 if (i) { 575 (*dd)[i].old.from = (*dd)[i-1].old.to; 576 (*dd)[i].new.from = (*dd)[i-1].new.to; 577 } 578 579 (void)fclose(fp[0]); 580 581 return (i); 582 } 583 584 static int 585 number(char **lc) 586 { 587 int nn; 588 589 nn = 0; 590 while (isdigit((unsigned char)(**lc))) 591 nn = nn*10 + *(*lc)++ - '0'; 592 593 return (nn); 594 } 595 596 static char * 597 getchange(FILE *b) 598 { 599 char *line; 600 601 while ((line = get_line(b, NULL))) { 602 if (isdigit((unsigned char)line[0])) 603 return (line); 604 } 605 606 return (NULL); 607 } 608 609 static char * 610 get_line(FILE *b, size_t *n) 611 { 612 char *cp; 613 size_t len; 614 static char *buf; 615 static size_t bufsize; 616 617 if ((cp = fgetln(b, &len)) == NULL) 618 return (NULL); 619 620 if (cp[len - 1] != '\n') 621 len++; 622 if (len + 1 > bufsize) { 623 do { 624 bufsize += 1024; 625 } while (len + 1 > bufsize); 626 buf = xreallocarray(buf, 1, bufsize); 627 } 628 memcpy(buf, cp, len - 1); 629 buf[len - 1] = '\n'; 630 buf[len] = '\0'; 631 if (n != NULL) 632 *n = len; 633 634 return (buf); 635 } 636 637 static int 638 merge(size_t m1, size_t m2) 639 { 640 struct diff *d1, *d2, *d3; 641 int dpl, j, t1, t2; 642 643 d1 = d13; 644 d2 = d23; 645 j = 0; 646 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 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 j = k > BUFSIZ ? BUFSIZ : k; 897 if (fread(block, 1, j, fp[2]) != j) 898 return (-1); 899 block[j] = '\0'; 900 diff_output("%s", block); 901 } 902 903 if (!oflag || !overlap[n]) 904 diff_output(".\n"); 905 else { 906 diff_output("%s\n.\n", f3mark); 907 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 908 } 909 } 910 911 return (overlapcnt); 912 } 913 914 static void 915 increase(void) 916 { 917 size_t newsz, incr; 918 919 /* are the memset(3) calls needed? */ 920 newsz = szchanges == 0 ? 64 : 2 * szchanges; 921 incr = newsz - szchanges; 922 923 d13 = xreallocarray(d13, newsz, sizeof(*d13)); 924 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 925 d23 = xreallocarray(d23, newsz, sizeof(*d23)); 926 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 927 de = xreallocarray(de, newsz, sizeof(*de)); 928 memset(de + szchanges, 0, incr * sizeof(*de)); 929 overlap = xreallocarray(overlap, newsz, sizeof(*overlap)); 930 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 931 szchanges = newsz; 932 } 933