1 /* $OpenBSD: diff3.c,v 1.27 2009/02/25 23:16:20 ray Exp $ */ 2 3 /* 4 * Copyright (C) Caldera International Inc. 2001-2002. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code and documentation must retain the above 11 * copyright notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed or owned by Caldera 18 * International, Inc. 19 * 4. Neither the name of Caldera International, Inc. nor the names of other 20 * contributors may be used to endorse or promote products derived from 21 * this software without specific prior written permission. 22 * 23 * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA 24 * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR 25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 27 * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT, 28 * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 29 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 30 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 32 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 33 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 */ 36 /*- 37 * Copyright (c) 1991, 1993 38 * The Regents of the University of California. All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the University nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 * 64 * @(#)diff3.c 8.1 (Berkeley) 6/6/93 65 */ 66 67 #ifndef lint 68 static const char copyright[] = 69 "@(#) Copyright (c) 1991, 1993\n\ 70 The Regents of the University of California. All rights reserved.\n"; 71 #endif /* not lint */ 72 73 #ifndef lint 74 static const char rcsid[] = 75 "$OpenBSD: diff3.c,v 1.27 2009/02/25 23:16:20 ray Exp $"; 76 #endif /* not lint */ 77 78 #include <ctype.h> 79 #include <err.h> 80 #include <stdio.h> 81 #include <stdlib.h> 82 #include <string.h> 83 #include <unistd.h> 84 85 #include "diff.h" 86 #include "rcsprog.h" 87 88 /* diff3 - 3-way differential file comparison */ 89 90 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 91 * 92 * d13 = diff report on f1 vs f3 93 * d23 = diff report on f2 vs f3 94 * f1, f2, f3 the 3 files 95 * if changes in f1 overlap with changes in f3, m1 and m3 are used 96 * to mark the overlaps; otherwise, the file names f1 and f3 are used 97 * (only for options E and X). 98 */ 99 100 /* 101 * "from" is first in range of changed lines; "to" is last+1 102 * from=to=line after point of insertion for added lines. 103 */ 104 struct range { 105 int from; 106 int to; 107 }; 108 109 struct diff { 110 struct range old; 111 struct range new; 112 }; 113 114 static size_t szchanges; 115 116 static struct diff *d13; 117 static struct diff *d23; 118 119 /* 120 * "de" is used to gather editing scripts. These are later spewed out in 121 * reverse order. Its first element must be all zero, the "new" component 122 * of "de" contains line positions or byte positions depending on when you 123 * look (!?). Array overlap indicates which sections in "de" correspond to 124 * lines that are different in all three files. 125 */ 126 static struct diff *de; 127 static char *overlap; 128 static int overlapcnt = 0; 129 static FILE *fp[3]; 130 static int cline[3]; /* # of the last-read line in each file (0-2) */ 131 132 /* 133 * the latest known correspondence between line numbers of the 3 files 134 * is stored in last[1-3]; 135 */ 136 static int last[4]; 137 static int eflag = 3; /* default -E for compatibility with former RCS */ 138 static int oflag = 1; /* default -E for compatibility with former RCS */ 139 static int debug = 0; 140 static char f1mark[256], f3mark[256]; /* markers for -E and -X */ 141 142 static int duplicate(struct range *, struct range *); 143 static int edit(struct diff *, int, int); 144 static char *getchange(FILE *); 145 static char *getline(FILE *, size_t *); 146 static int number(char **); 147 static ssize_t readin(char *, struct diff **); 148 static int skip(int, int, char *); 149 static int edscript(int); 150 static int merge(size_t, size_t); 151 static void change(int, struct range *, int); 152 static void keep(int, struct range *); 153 static void prange(struct range *); 154 static void repos(int); 155 static void separate(const char *); 156 static void increase(void); 157 static int diff3_internal(int, char **, const char *, const char *); 158 159 int diff3_conflicts = 0; 160 161 /* 162 * For merge(1). 163 */ 164 BUF * 165 merge_diff3(char **av, int flags) 166 { 167 int argc; 168 char *argv[5], *dp13, *dp23, *path1, *path2, *path3; 169 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 170 u_char *data, *patch; 171 size_t dlen, plen; 172 173 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 174 dp13 = dp23 = path1 = path2 = path3 = NULL; 175 data = patch = NULL; 176 177 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 178 oflag = 0; 179 180 if ((b1 = rcs_buf_load(av[0], BUF_AUTOEXT)) == NULL) 181 goto out; 182 if ((b2 = rcs_buf_load(av[1], BUF_AUTOEXT)) == NULL) 183 goto out; 184 if ((b3 = rcs_buf_load(av[2], BUF_AUTOEXT)) == NULL) 185 goto out; 186 187 d1 = rcs_buf_alloc(128, BUF_AUTOEXT); 188 d2 = rcs_buf_alloc(128, BUF_AUTOEXT); 189 diffb = rcs_buf_alloc(128, BUF_AUTOEXT); 190 191 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 192 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 193 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 194 195 rcs_buf_write_stmp(b1, path1); 196 rcs_buf_write_stmp(b2, path2); 197 rcs_buf_write_stmp(b3, path3); 198 199 rcs_buf_free(b2); 200 b2 = NULL; 201 202 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 203 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 204 rcs_buf_free(diffb); 205 diffb = NULL; 206 goto out; 207 } 208 209 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 210 rcs_buf_write_stmp(d1, dp13); 211 212 rcs_buf_free(d1); 213 d1 = NULL; 214 215 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 216 rcs_buf_write_stmp(d2, dp23); 217 218 rcs_buf_free(d2); 219 d2 = NULL; 220 221 argc = 0; 222 diffbuf = diffb; 223 argv[argc++] = dp13; 224 argv[argc++] = dp23; 225 argv[argc++] = path1; 226 argv[argc++] = path2; 227 argv[argc++] = path3; 228 229 diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]); 230 if (diff3_conflicts < 0) { 231 rcs_buf_free(diffb); 232 diffb = NULL; 233 goto out; 234 } 235 236 plen = rcs_buf_len(diffb); 237 patch = rcs_buf_release(diffb); 238 dlen = rcs_buf_len(b1); 239 data = rcs_buf_release(b1); 240 241 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 242 goto out; 243 244 if (!(flags & QUIET) && diff3_conflicts != 0) 245 warnx("warning: overlaps or other problems during merge"); 246 247 out: 248 if (b2 != NULL) 249 rcs_buf_free(b2); 250 if (b3 != NULL) 251 rcs_buf_free(b3); 252 if (d1 != NULL) 253 rcs_buf_free(d1); 254 if (d2 != NULL) 255 rcs_buf_free(d2); 256 257 (void)unlink(path1); 258 (void)unlink(path2); 259 (void)unlink(path3); 260 (void)unlink(dp13); 261 (void)unlink(dp23); 262 263 if (path1 != NULL) 264 xfree(path1); 265 if (path2 != NULL) 266 xfree(path2); 267 if (path3 != NULL) 268 xfree(path3); 269 if (dp13 != NULL) 270 xfree(dp13); 271 if (dp23 != NULL) 272 xfree(dp23); 273 if (data != NULL) 274 xfree(data); 275 if (patch != NULL) 276 xfree(patch); 277 278 return (diffb); 279 } 280 281 BUF * 282 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 283 { 284 int argc; 285 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 286 char *dp13, *dp23, *path1, *path2, *path3; 287 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 288 size_t dlen, plen; 289 u_char *data, *patch; 290 291 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 292 dp13 = dp23 = path1 = path2 = path3 = NULL; 293 data = patch = NULL; 294 295 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 296 oflag = 0; 297 298 rcsnum_tostr(rev1, r1, sizeof(r1)); 299 rcsnum_tostr(rev2, r2, sizeof(r2)); 300 301 if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL) 302 goto out; 303 304 if (!(flags & QUIET)) 305 (void)fprintf(stderr, "retrieving revision %s\n", r1); 306 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 307 goto out; 308 309 if (!(flags & QUIET)) 310 (void)fprintf(stderr, "retrieving revision %s\n", r2); 311 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 312 goto out; 313 314 d1 = rcs_buf_alloc(128, BUF_AUTOEXT); 315 d2 = rcs_buf_alloc(128, BUF_AUTOEXT); 316 diffb = rcs_buf_alloc(128, BUF_AUTOEXT); 317 318 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 319 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 320 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 321 322 rcs_buf_write_stmp(b1, path1); 323 rcs_buf_write_stmp(b2, path2); 324 rcs_buf_write_stmp(b3, path3); 325 326 rcs_buf_free(b2); 327 b2 = NULL; 328 329 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 330 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 331 rcs_buf_free(diffb); 332 diffb = NULL; 333 goto out; 334 } 335 336 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 337 rcs_buf_write_stmp(d1, dp13); 338 339 rcs_buf_free(d1); 340 d1 = NULL; 341 342 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 343 rcs_buf_write_stmp(d2, dp23); 344 345 rcs_buf_free(d2); 346 d2 = NULL; 347 348 argc = 0; 349 diffbuf = diffb; 350 argv[argc++] = dp13; 351 argv[argc++] = dp23; 352 argv[argc++] = path1; 353 argv[argc++] = path2; 354 argv[argc++] = path3; 355 356 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 357 if (diff3_conflicts < 0) { 358 rcs_buf_free(diffb); 359 diffb = NULL; 360 goto out; 361 } 362 363 plen = rcs_buf_len(diffb); 364 patch = rcs_buf_release(diffb); 365 dlen = rcs_buf_len(b1); 366 data = rcs_buf_release(b1); 367 368 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 369 goto out; 370 371 if (!(flags & QUIET) && diff3_conflicts != 0) 372 warnx("warning: overlaps or other problems during merge"); 373 374 out: 375 if (b2 != NULL) 376 rcs_buf_free(b2); 377 if (b3 != NULL) 378 rcs_buf_free(b3); 379 if (d1 != NULL) 380 rcs_buf_free(d1); 381 if (d2 != NULL) 382 rcs_buf_free(d2); 383 384 (void)unlink(path1); 385 (void)unlink(path2); 386 (void)unlink(path3); 387 (void)unlink(dp13); 388 (void)unlink(dp23); 389 390 if (path1 != NULL) 391 xfree(path1); 392 if (path2 != NULL) 393 xfree(path2); 394 if (path3 != NULL) 395 xfree(path3); 396 if (dp13 != NULL) 397 xfree(dp13); 398 if (dp23 != NULL) 399 xfree(dp23); 400 if (data != NULL) 401 xfree(data); 402 if (patch != NULL) 403 xfree(patch); 404 405 return (diffb); 406 } 407 408 static int 409 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 410 { 411 ssize_t m, n; 412 int i; 413 414 if (argc < 5) 415 return (-1); 416 417 if (oflag) { 418 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 419 if (i < 0 || i >= (int)sizeof(f1mark)) 420 errx(1, "diff3_internal: string truncated"); 421 422 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 423 if (i < 0 || i >= (int)sizeof(f3mark)) 424 errx(1, "diff3_internal: string truncated"); 425 } 426 427 increase(); 428 if ((m = readin(argv[0], &d13)) < 0) { 429 warn("%s", argv[0]); 430 return (-1); 431 } 432 if ((n = readin(argv[1], &d23)) < 0) { 433 warn("%s", argv[1]); 434 return (-1); 435 } 436 437 for (i = 0; i <= 2; i++) 438 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 439 warn("%s", argv[i + 2]); 440 return (-1); 441 } 442 443 return (merge(m, n)); 444 } 445 446 int 447 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 448 { 449 char op, *ep; 450 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 451 int start, end, i, lineno; 452 u_char tmp; 453 454 dlp = TAILQ_FIRST(&(dlines->l_lines)); 455 lp = TAILQ_FIRST(&(plines->l_lines)); 456 457 end = 0; 458 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 459 lp = TAILQ_NEXT(lp, l_list)) { 460 /* Skip blank lines */ 461 if (lp->l_len < 2) 462 continue; 463 /* NUL-terminate line buffer for strtol() safety. */ 464 tmp = lp->l_line[lp->l_len - 1]; 465 lp->l_line[lp->l_len - 1] = '\0'; 466 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 467 op = lp->l_line[lp->l_len - 2]; 468 start = (int)strtol(lp->l_line, &ep, 10); 469 /* Restore the last byte of the buffer */ 470 lp->l_line[lp->l_len - 1] = tmp; 471 if (op == 'a') { 472 if (start > dlines->l_nblines || 473 start < 0 || *ep != 'a') 474 errx(1, "ed_patch_lines"); 475 } else if (op == 'c') { 476 if (start > dlines->l_nblines || 477 start < 0 || (*ep != ',' && *ep != 'c')) 478 errx(1, "ed_patch_lines"); 479 480 if (*ep == ',') { 481 ep++; 482 end = (int)strtol(ep, &ep, 10); 483 if (end < 0 || *ep != 'c') 484 errx(1, "ed_patch_lines"); 485 } else { 486 end = start; 487 } 488 } 489 490 491 for (;;) { 492 if (dlp == NULL) 493 break; 494 if (dlp->l_lineno == start) 495 break; 496 if (dlp->l_lineno > start) { 497 dlp = TAILQ_PREV(dlp, rcs_tqh, l_list); 498 } else if (dlp->l_lineno < start) { 499 ndlp = TAILQ_NEXT(dlp, l_list); 500 if (ndlp->l_lineno > start) 501 break; 502 dlp = ndlp; 503 } 504 } 505 506 if (dlp == NULL) 507 errx(1, "ed_patch_lines"); 508 509 510 if (op == 'c') { 511 insert_after = TAILQ_PREV(dlp, rcs_tqh, l_list); 512 for (i = 0; i <= (end - start); i++) { 513 ndlp = TAILQ_NEXT(dlp, l_list); 514 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 515 dlp = ndlp; 516 } 517 dlp = insert_after; 518 } 519 520 if (op == 'a' || op == 'c') { 521 for (;;) { 522 ndlp = lp; 523 lp = TAILQ_NEXT(lp, l_list); 524 if (lp == NULL) 525 errx(1, "ed_patch_lines"); 526 527 if (!memcmp(lp->l_line, ".", 1)) 528 break; 529 530 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 531 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 532 lp, l_list); 533 dlp = lp; 534 535 lp->l_lineno = start; 536 lp = ndlp; 537 } 538 } 539 540 /* 541 * always resort lines as the markers might be put at the 542 * same line as we first started editing. 543 */ 544 lineno = 0; 545 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 546 sort->l_lineno = lineno++; 547 dlines->l_nblines = lineno - 1; 548 } 549 550 return (0); 551 } 552 553 /* 554 * Pick up the line numbers of all changes from one change file. 555 * (This puts the numbers in a vector, which is not strictly necessary, 556 * since the vector is processed in one sequential pass. 557 * The vector could be optimized out of existence) 558 */ 559 static ssize_t 560 readin(char *name, struct diff **dd) 561 { 562 int a, b, c, d; 563 char kind, *p; 564 size_t i; 565 566 fp[0] = fopen(name, "r"); 567 if (fp[0] == NULL) 568 return (-1); 569 for (i = 0; (p = getchange(fp[0])); i++) { 570 if (i >= szchanges - 1) 571 increase(); 572 a = b = number(&p); 573 if (*p == ',') { 574 p++; 575 b = number(&p); 576 } 577 kind = *p++; 578 c = d = number(&p); 579 if (*p==',') { 580 p++; 581 d = number(&p); 582 } 583 if (kind == 'a') 584 a++; 585 if (kind == 'd') 586 c++; 587 b++; 588 d++; 589 (*dd)[i].old.from = a; 590 (*dd)[i].old.to = b; 591 (*dd)[i].new.from = c; 592 (*dd)[i].new.to = d; 593 } 594 595 if (i) { 596 (*dd)[i].old.from = (*dd)[i-1].old.to; 597 (*dd)[i].new.from = (*dd)[i-1].new.to; 598 } 599 (void)fclose(fp[0]); 600 601 return (i); 602 } 603 604 static int 605 number(char **lc) 606 { 607 int nn; 608 609 nn = 0; 610 while (isdigit((unsigned char)(**lc))) 611 nn = nn*10 + *(*lc)++ - '0'; 612 613 return (nn); 614 } 615 616 static char * 617 getchange(FILE *b) 618 { 619 char *line; 620 621 while ((line = getline(b, NULL))) { 622 if (isdigit((unsigned char)line[0])) 623 return (line); 624 } 625 626 return (NULL); 627 } 628 629 static char * 630 getline(FILE *b, size_t *n) 631 { 632 char *cp; 633 size_t len; 634 static char *buf; 635 static size_t bufsize; 636 637 if ((cp = fgetln(b, &len)) == NULL) 638 return (NULL); 639 640 if (cp[len - 1] != '\n') 641 len++; 642 if (len + 1 > bufsize) { 643 do { 644 bufsize += 1024; 645 } while (len + 1 > bufsize); 646 buf = xrealloc(buf, 1, bufsize); 647 } 648 memcpy(buf, cp, len - 1); 649 buf[len - 1] = '\n'; 650 buf[len] = '\0'; 651 if (n != NULL) 652 *n = len; 653 654 return (buf); 655 } 656 657 static int 658 merge(size_t m1, size_t m2) 659 { 660 struct diff *d1, *d2, *d3; 661 int dpl, j, t1, t2; 662 663 d1 = d13; 664 d2 = d23; 665 j = 0; 666 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 667 if (debug) { 668 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 669 d1->old.from, d1->old.to, 670 d1->new.from, d1->new.to, 671 d2->old.from, d2->old.to, 672 d2->new.from, d2->new.to); 673 } 674 675 /* first file is different from others */ 676 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 677 /* stuff peculiar to 1st file */ 678 if (eflag==0) { 679 separate("1"); 680 change(1, &d1->old, 0); 681 keep(2, &d1->new); 682 change(3, &d1->new, 0); 683 } 684 d1++; 685 continue; 686 } 687 688 /* second file is different from others */ 689 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 690 if (eflag==0) { 691 separate("2"); 692 keep(1, &d2->new); 693 change(2, &d2->old, 0); 694 change(3, &d2->new, 0); 695 } 696 d2++; 697 continue; 698 } 699 700 /* 701 * Merge overlapping changes in first file 702 * this happens after extension (see below). 703 */ 704 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 705 d1[1].old.from = d1->old.from; 706 d1[1].new.from = d1->new.from; 707 d1++; 708 continue; 709 } 710 711 /* merge overlapping changes in second */ 712 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 713 d2[1].old.from = d2->old.from; 714 d2[1].new.from = d2->new.from; 715 d2++; 716 continue; 717 } 718 /* stuff peculiar to third file or different in all */ 719 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 720 dpl = duplicate(&d1->old,&d2->old); 721 if (dpl == -1) 722 return (-1); 723 724 /* 725 * dpl = 0 means all files differ 726 * dpl = 1 means files 1 and 2 identical 727 */ 728 if (eflag==0) { 729 separate(dpl ? "3" : ""); 730 change(1, &d1->old, dpl); 731 change(2, &d2->old, 0); 732 d3 = d1->old.to > d1->old.from ? d1 : d2; 733 change(3, &d3->new, 0); 734 } else 735 j = edit(d1, dpl, j); 736 d1++; 737 d2++; 738 continue; 739 } 740 741 /* 742 * Overlapping changes from file 1 and 2; extend changes 743 * appropriately to make them coincide. 744 */ 745 if (d1->new.from < d2->new.from) { 746 d2->old.from -= d2->new.from-d1->new.from; 747 d2->new.from = d1->new.from; 748 } else if (d2->new.from < d1->new.from) { 749 d1->old.from -= d1->new.from-d2->new.from; 750 d1->new.from = d2->new.from; 751 } 752 if (d1->new.to > d2->new.to) { 753 d2->old.to += d1->new.to - d2->new.to; 754 d2->new.to = d1->new.to; 755 } else if (d2->new.to > d1->new.to) { 756 d1->old.to += d2->new.to - d1->new.to; 757 d1->new.to = d2->new.to; 758 } 759 } 760 761 return (edscript(j)); 762 } 763 764 static void 765 separate(const char *s) 766 { 767 diff_output("====%s\n", s); 768 } 769 770 /* 771 * The range of lines rold.from thru rold.to in file i is to be changed. 772 * It is to be printed only if it does not duplicate something to be 773 * printed later. 774 */ 775 static void 776 change(int i, struct range *rold, int fdup) 777 { 778 diff_output("%d:", i); 779 last[i] = rold->to; 780 prange(rold); 781 if (fdup || debug) 782 return; 783 i--; 784 (void)skip(i, rold->from, NULL); 785 (void)skip(i, rold->to, " "); 786 } 787 788 /* 789 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 790 */ 791 static void 792 prange(struct range *rold) 793 { 794 if (rold->to <= rold->from) 795 diff_output("%da\n", rold->from - 1); 796 else { 797 diff_output("%d", rold->from); 798 if (rold->to > rold->from+1) 799 diff_output(",%d", rold->to - 1); 800 diff_output("c\n"); 801 } 802 } 803 804 /* 805 * No difference was reported by diff between file 1 (or 2) and file 3, 806 * and an artificial dummy difference (trange) must be ginned up to 807 * correspond to the change reported in the other file. 808 */ 809 static void 810 keep(int i, struct range *rnew) 811 { 812 int delta; 813 struct range trange; 814 815 delta = last[3] - last[i]; 816 trange.from = rnew->from - delta; 817 trange.to = rnew->to - delta; 818 change(i, &trange, 1); 819 } 820 821 /* 822 * skip to just before line number from in file "i". If "pr" is non-NULL, 823 * print all skipped stuff with string pr as a prefix. 824 */ 825 static int 826 skip(int i, int from, char *pr) 827 { 828 size_t j, n; 829 char *line; 830 831 for (n = 0; cline[i] < from - 1; n += j) { 832 if ((line = getline(fp[i], &j)) == NULL) 833 return (-1); 834 if (pr != NULL) 835 diff_output("%s%s", pr, line); 836 cline[i]++; 837 } 838 return ((int) n); 839 } 840 841 /* 842 * Return 1 or 0 according as the old range (in file 1) contains exactly 843 * the same data as the new range (in file 2). 844 */ 845 static int 846 duplicate(struct range *r1, struct range *r2) 847 { 848 int c,d; 849 int nchar; 850 int nline; 851 852 if (r1->to-r1->from != r2->to-r2->from) 853 return (0); 854 (void)skip(0, r1->from, NULL); 855 (void)skip(1, r2->from, NULL); 856 nchar = 0; 857 for (nline=0; nline < r1->to - r1->from; nline++) { 858 do { 859 c = getc(fp[0]); 860 d = getc(fp[1]); 861 if (c == -1 || d== -1) 862 return (-1); 863 nchar++; 864 if (c != d) { 865 repos(nchar); 866 return (0); 867 } 868 } while (c != '\n'); 869 } 870 repos(nchar); 871 return (1); 872 } 873 874 static void 875 repos(int nchar) 876 { 877 int i; 878 879 for (i = 0; i < 2; i++) 880 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 881 } 882 883 /* 884 * collect an editing script for later regurgitation 885 */ 886 static int 887 edit(struct diff *diff, int fdup, int j) 888 { 889 if (((fdup + 1) & eflag) == 0) 890 return (j); 891 j++; 892 overlap[j] = !fdup; 893 if (!fdup) 894 overlapcnt++; 895 de[j].old.from = diff->old.from; 896 de[j].old.to = diff->old.to; 897 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 898 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 899 return (j); 900 } 901 902 /* regurgitate */ 903 static int 904 edscript(int n) 905 { 906 int j, k; 907 char block[BUFSIZ+1]; 908 909 for (n = n; n > 0; n--) { 910 if (!oflag || !overlap[n]) 911 prange(&de[n].old); 912 else 913 diff_output("%da\n=======\n", de[n].old.to -1); 914 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 915 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 916 j = k > BUFSIZ ? BUFSIZ : k; 917 if (fread(block, 1, (size_t)j, 918 fp[2]) != (size_t)j) 919 return (-1); 920 block[j] = '\0'; 921 diff_output("%s", block); 922 } 923 924 if (!oflag || !overlap[n]) 925 diff_output(".\n"); 926 else { 927 diff_output("%s\n.\n", f3mark); 928 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 929 } 930 } 931 932 return (overlapcnt); 933 } 934 935 static void 936 increase(void) 937 { 938 size_t newsz, incr; 939 940 /* are the memset(3) calls needed? */ 941 newsz = szchanges == 0 ? 64 : 2 * szchanges; 942 incr = newsz - szchanges; 943 944 d13 = xrealloc(d13, newsz, sizeof(*d13)); 945 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 946 d23 = xrealloc(d23, newsz, sizeof(*d23)); 947 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 948 de = xrealloc(de, newsz, sizeof(*de)); 949 memset(de + szchanges, 0, incr * sizeof(*de)); 950 overlap = xrealloc(overlap, newsz, sizeof(*overlap)); 951 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 952 szchanges = newsz; 953 } 954