1 /* $OpenBSD: diff3.c,v 1.28 2009/10/27 23:59:42 deraadt 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[256], f3mark[256]; /* markers for -E and -X */ 130 131 static int duplicate(struct range *, struct range *); 132 static int edit(struct diff *, int, int); 133 static char *getchange(FILE *); 134 static char *getline(FILE *, size_t *); 135 static int number(char **); 136 static ssize_t readin(char *, struct diff **); 137 static int skip(int, int, char *); 138 static int edscript(int); 139 static int merge(size_t, size_t); 140 static void change(int, struct range *, int); 141 static void keep(int, struct range *); 142 static void prange(struct range *); 143 static void repos(int); 144 static void separate(const char *); 145 static void increase(void); 146 static int diff3_internal(int, char **, const char *, const char *); 147 148 int diff3_conflicts = 0; 149 150 /* 151 * For merge(1). 152 */ 153 BUF * 154 merge_diff3(char **av, int flags) 155 { 156 int argc; 157 char *argv[5], *dp13, *dp23, *path1, *path2, *path3; 158 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 159 u_char *data, *patch; 160 size_t dlen, plen; 161 162 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 163 dp13 = dp23 = path1 = path2 = path3 = NULL; 164 data = patch = NULL; 165 166 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 167 oflag = 0; 168 169 if ((b1 = rcs_buf_load(av[0], BUF_AUTOEXT)) == NULL) 170 goto out; 171 if ((b2 = rcs_buf_load(av[1], BUF_AUTOEXT)) == NULL) 172 goto out; 173 if ((b3 = rcs_buf_load(av[2], BUF_AUTOEXT)) == NULL) 174 goto out; 175 176 d1 = rcs_buf_alloc(128, BUF_AUTOEXT); 177 d2 = rcs_buf_alloc(128, BUF_AUTOEXT); 178 diffb = rcs_buf_alloc(128, BUF_AUTOEXT); 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 rcs_buf_write_stmp(b1, path1); 185 rcs_buf_write_stmp(b2, path2); 186 rcs_buf_write_stmp(b3, path3); 187 188 rcs_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 rcs_buf_free(diffb); 194 diffb = NULL; 195 goto out; 196 } 197 198 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 199 rcs_buf_write_stmp(d1, dp13); 200 201 rcs_buf_free(d1); 202 d1 = NULL; 203 204 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 205 rcs_buf_write_stmp(d2, dp23); 206 207 rcs_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 rcs_buf_free(diffb); 221 diffb = NULL; 222 goto out; 223 } 224 225 plen = rcs_buf_len(diffb); 226 patch = rcs_buf_release(diffb); 227 dlen = rcs_buf_len(b1); 228 data = rcs_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 rcs_buf_free(b2); 239 if (b3 != NULL) 240 rcs_buf_free(b3); 241 if (d1 != NULL) 242 rcs_buf_free(d1); 243 if (d2 != NULL) 244 rcs_buf_free(d2); 245 246 (void)unlink(path1); 247 (void)unlink(path2); 248 (void)unlink(path3); 249 (void)unlink(dp13); 250 (void)unlink(dp23); 251 252 if (path1 != NULL) 253 xfree(path1); 254 if (path2 != NULL) 255 xfree(path2); 256 if (path3 != NULL) 257 xfree(path3); 258 if (dp13 != NULL) 259 xfree(dp13); 260 if (dp23 != NULL) 261 xfree(dp23); 262 if (data != NULL) 263 xfree(data); 264 if (patch != NULL) 265 xfree(patch); 266 267 return (diffb); 268 } 269 270 BUF * 271 rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags) 272 { 273 int argc; 274 char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ]; 275 char *dp13, *dp23, *path1, *path2, *path3; 276 BUF *b1, *b2, *b3, *d1, *d2, *diffb; 277 size_t dlen, plen; 278 u_char *data, *patch; 279 280 b1 = b2 = b3 = d1 = d2 = diffb = NULL; 281 dp13 = dp23 = path1 = path2 = path3 = NULL; 282 data = patch = NULL; 283 284 if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG)) 285 oflag = 0; 286 287 rcsnum_tostr(rev1, r1, sizeof(r1)); 288 rcsnum_tostr(rev2, r2, sizeof(r2)); 289 290 if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL) 291 goto out; 292 293 if (!(flags & QUIET)) 294 (void)fprintf(stderr, "retrieving revision %s\n", r1); 295 if ((b2 = rcs_getrev(rf, rev1)) == NULL) 296 goto out; 297 298 if (!(flags & QUIET)) 299 (void)fprintf(stderr, "retrieving revision %s\n", r2); 300 if ((b3 = rcs_getrev(rf, rev2)) == NULL) 301 goto out; 302 303 d1 = rcs_buf_alloc(128, BUF_AUTOEXT); 304 d2 = rcs_buf_alloc(128, BUF_AUTOEXT); 305 diffb = rcs_buf_alloc(128, BUF_AUTOEXT); 306 307 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir); 308 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir); 309 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir); 310 311 rcs_buf_write_stmp(b1, path1); 312 rcs_buf_write_stmp(b2, path2); 313 rcs_buf_write_stmp(b3, path3); 314 315 rcs_buf_free(b2); 316 b2 = NULL; 317 318 if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) || 319 (diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) { 320 rcs_buf_free(diffb); 321 diffb = NULL; 322 goto out; 323 } 324 325 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir); 326 rcs_buf_write_stmp(d1, dp13); 327 328 rcs_buf_free(d1); 329 d1 = NULL; 330 331 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir); 332 rcs_buf_write_stmp(d2, dp23); 333 334 rcs_buf_free(d2); 335 d2 = NULL; 336 337 argc = 0; 338 diffbuf = diffb; 339 argv[argc++] = dp13; 340 argv[argc++] = dp23; 341 argv[argc++] = path1; 342 argv[argc++] = path2; 343 argv[argc++] = path3; 344 345 diff3_conflicts = diff3_internal(argc, argv, workfile, r2); 346 if (diff3_conflicts < 0) { 347 rcs_buf_free(diffb); 348 diffb = NULL; 349 goto out; 350 } 351 352 plen = rcs_buf_len(diffb); 353 patch = rcs_buf_release(diffb); 354 dlen = rcs_buf_len(b1); 355 data = rcs_buf_release(b1); 356 357 if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL) 358 goto out; 359 360 if (!(flags & QUIET) && diff3_conflicts != 0) 361 warnx("warning: overlaps or other problems during merge"); 362 363 out: 364 if (b2 != NULL) 365 rcs_buf_free(b2); 366 if (b3 != NULL) 367 rcs_buf_free(b3); 368 if (d1 != NULL) 369 rcs_buf_free(d1); 370 if (d2 != NULL) 371 rcs_buf_free(d2); 372 373 (void)unlink(path1); 374 (void)unlink(path2); 375 (void)unlink(path3); 376 (void)unlink(dp13); 377 (void)unlink(dp23); 378 379 if (path1 != NULL) 380 xfree(path1); 381 if (path2 != NULL) 382 xfree(path2); 383 if (path3 != NULL) 384 xfree(path3); 385 if (dp13 != NULL) 386 xfree(dp13); 387 if (dp23 != NULL) 388 xfree(dp23); 389 if (data != NULL) 390 xfree(data); 391 if (patch != NULL) 392 xfree(patch); 393 394 return (diffb); 395 } 396 397 static int 398 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 399 { 400 ssize_t m, n; 401 int i; 402 403 if (argc < 5) 404 return (-1); 405 406 if (oflag) { 407 i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 408 if (i < 0 || i >= (int)sizeof(f1mark)) 409 errx(1, "diff3_internal: string truncated"); 410 411 i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 412 if (i < 0 || i >= (int)sizeof(f3mark)) 413 errx(1, "diff3_internal: string truncated"); 414 } 415 416 increase(); 417 if ((m = readin(argv[0], &d13)) < 0) { 418 warn("%s", argv[0]); 419 return (-1); 420 } 421 if ((n = readin(argv[1], &d23)) < 0) { 422 warn("%s", argv[1]); 423 return (-1); 424 } 425 426 for (i = 0; i <= 2; i++) 427 if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) { 428 warn("%s", argv[i + 2]); 429 return (-1); 430 } 431 432 return (merge(m, n)); 433 } 434 435 int 436 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 437 { 438 char op, *ep; 439 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 440 int start, end, i, lineno; 441 u_char tmp; 442 443 dlp = TAILQ_FIRST(&(dlines->l_lines)); 444 lp = TAILQ_FIRST(&(plines->l_lines)); 445 446 end = 0; 447 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 448 lp = TAILQ_NEXT(lp, l_list)) { 449 /* Skip blank lines */ 450 if (lp->l_len < 2) 451 continue; 452 /* NUL-terminate line buffer for strtol() safety. */ 453 tmp = lp->l_line[lp->l_len - 1]; 454 lp->l_line[lp->l_len - 1] = '\0'; 455 /* len - 1 is NUL terminator so we use len - 2 for 'op' */ 456 op = lp->l_line[lp->l_len - 2]; 457 start = (int)strtol(lp->l_line, &ep, 10); 458 /* Restore the last byte of the buffer */ 459 lp->l_line[lp->l_len - 1] = tmp; 460 if (op == 'a') { 461 if (start > dlines->l_nblines || 462 start < 0 || *ep != 'a') 463 errx(1, "ed_patch_lines"); 464 } else if (op == 'c') { 465 if (start > dlines->l_nblines || 466 start < 0 || (*ep != ',' && *ep != 'c')) 467 errx(1, "ed_patch_lines"); 468 469 if (*ep == ',') { 470 ep++; 471 end = (int)strtol(ep, &ep, 10); 472 if (end < 0 || *ep != 'c') 473 errx(1, "ed_patch_lines"); 474 } else { 475 end = start; 476 } 477 } 478 479 480 for (;;) { 481 if (dlp == NULL) 482 break; 483 if (dlp->l_lineno == start) 484 break; 485 if (dlp->l_lineno > start) { 486 dlp = TAILQ_PREV(dlp, rcs_tqh, l_list); 487 } else if (dlp->l_lineno < start) { 488 ndlp = TAILQ_NEXT(dlp, l_list); 489 if (ndlp->l_lineno > start) 490 break; 491 dlp = ndlp; 492 } 493 } 494 495 if (dlp == NULL) 496 errx(1, "ed_patch_lines"); 497 498 499 if (op == 'c') { 500 insert_after = TAILQ_PREV(dlp, rcs_tqh, l_list); 501 for (i = 0; i <= (end - start); i++) { 502 ndlp = TAILQ_NEXT(dlp, l_list); 503 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 504 dlp = ndlp; 505 } 506 dlp = insert_after; 507 } 508 509 if (op == 'a' || op == 'c') { 510 for (;;) { 511 ndlp = lp; 512 lp = TAILQ_NEXT(lp, l_list); 513 if (lp == NULL) 514 errx(1, "ed_patch_lines"); 515 516 if (!memcmp(lp->l_line, ".", 1)) 517 break; 518 519 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 520 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 521 lp, l_list); 522 dlp = lp; 523 524 lp->l_lineno = start; 525 lp = ndlp; 526 } 527 } 528 529 /* 530 * always resort lines as the markers might be put at the 531 * same line as we first started editing. 532 */ 533 lineno = 0; 534 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 535 sort->l_lineno = lineno++; 536 dlines->l_nblines = lineno - 1; 537 } 538 539 return (0); 540 } 541 542 /* 543 * Pick up the line numbers of all changes from one change file. 544 * (This puts the numbers in a vector, which is not strictly necessary, 545 * since the vector is processed in one sequential pass. 546 * The vector could be optimized out of existence) 547 */ 548 static ssize_t 549 readin(char *name, struct diff **dd) 550 { 551 int a, b, c, d; 552 char kind, *p; 553 size_t i; 554 555 fp[0] = fopen(name, "r"); 556 if (fp[0] == NULL) 557 return (-1); 558 for (i = 0; (p = getchange(fp[0])); i++) { 559 if (i >= szchanges - 1) 560 increase(); 561 a = b = number(&p); 562 if (*p == ',') { 563 p++; 564 b = number(&p); 565 } 566 kind = *p++; 567 c = d = number(&p); 568 if (*p==',') { 569 p++; 570 d = number(&p); 571 } 572 if (kind == 'a') 573 a++; 574 if (kind == 'd') 575 c++; 576 b++; 577 d++; 578 (*dd)[i].old.from = a; 579 (*dd)[i].old.to = b; 580 (*dd)[i].new.from = c; 581 (*dd)[i].new.to = d; 582 } 583 584 if (i) { 585 (*dd)[i].old.from = (*dd)[i-1].old.to; 586 (*dd)[i].new.from = (*dd)[i-1].new.to; 587 } 588 (void)fclose(fp[0]); 589 590 return (i); 591 } 592 593 static int 594 number(char **lc) 595 { 596 int nn; 597 598 nn = 0; 599 while (isdigit((unsigned char)(**lc))) 600 nn = nn*10 + *(*lc)++ - '0'; 601 602 return (nn); 603 } 604 605 static char * 606 getchange(FILE *b) 607 { 608 char *line; 609 610 while ((line = getline(b, NULL))) { 611 if (isdigit((unsigned char)line[0])) 612 return (line); 613 } 614 615 return (NULL); 616 } 617 618 static char * 619 getline(FILE *b, size_t *n) 620 { 621 char *cp; 622 size_t len; 623 static char *buf; 624 static size_t bufsize; 625 626 if ((cp = fgetln(b, &len)) == NULL) 627 return (NULL); 628 629 if (cp[len - 1] != '\n') 630 len++; 631 if (len + 1 > bufsize) { 632 do { 633 bufsize += 1024; 634 } while (len + 1 > bufsize); 635 buf = xrealloc(buf, 1, bufsize); 636 } 637 memcpy(buf, cp, len - 1); 638 buf[len - 1] = '\n'; 639 buf[len] = '\0'; 640 if (n != NULL) 641 *n = len; 642 643 return (buf); 644 } 645 646 static int 647 merge(size_t m1, size_t m2) 648 { 649 struct diff *d1, *d2, *d3; 650 int dpl, j, t1, t2; 651 652 d1 = d13; 653 d2 = d23; 654 j = 0; 655 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 656 if (debug) { 657 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 658 d1->old.from, d1->old.to, 659 d1->new.from, d1->new.to, 660 d2->old.from, d2->old.to, 661 d2->new.from, d2->new.to); 662 } 663 664 /* first file is different from others */ 665 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 666 /* stuff peculiar to 1st file */ 667 if (eflag==0) { 668 separate("1"); 669 change(1, &d1->old, 0); 670 keep(2, &d1->new); 671 change(3, &d1->new, 0); 672 } 673 d1++; 674 continue; 675 } 676 677 /* second file is different from others */ 678 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 679 if (eflag==0) { 680 separate("2"); 681 keep(1, &d2->new); 682 change(2, &d2->old, 0); 683 change(3, &d2->new, 0); 684 } 685 d2++; 686 continue; 687 } 688 689 /* 690 * Merge overlapping changes in first file 691 * this happens after extension (see below). 692 */ 693 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 694 d1[1].old.from = d1->old.from; 695 d1[1].new.from = d1->new.from; 696 d1++; 697 continue; 698 } 699 700 /* merge overlapping changes in second */ 701 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 702 d2[1].old.from = d2->old.from; 703 d2[1].new.from = d2->new.from; 704 d2++; 705 continue; 706 } 707 /* stuff peculiar to third file or different in all */ 708 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 709 dpl = duplicate(&d1->old,&d2->old); 710 if (dpl == -1) 711 return (-1); 712 713 /* 714 * dpl = 0 means all files differ 715 * dpl = 1 means files 1 and 2 identical 716 */ 717 if (eflag==0) { 718 separate(dpl ? "3" : ""); 719 change(1, &d1->old, dpl); 720 change(2, &d2->old, 0); 721 d3 = d1->old.to > d1->old.from ? d1 : d2; 722 change(3, &d3->new, 0); 723 } else 724 j = edit(d1, dpl, j); 725 d1++; 726 d2++; 727 continue; 728 } 729 730 /* 731 * Overlapping changes from file 1 and 2; extend changes 732 * appropriately to make them coincide. 733 */ 734 if (d1->new.from < d2->new.from) { 735 d2->old.from -= d2->new.from-d1->new.from; 736 d2->new.from = d1->new.from; 737 } else if (d2->new.from < d1->new.from) { 738 d1->old.from -= d1->new.from-d2->new.from; 739 d1->new.from = d2->new.from; 740 } 741 if (d1->new.to > d2->new.to) { 742 d2->old.to += d1->new.to - d2->new.to; 743 d2->new.to = d1->new.to; 744 } else if (d2->new.to > d1->new.to) { 745 d1->old.to += d2->new.to - d1->new.to; 746 d1->new.to = d2->new.to; 747 } 748 } 749 750 return (edscript(j)); 751 } 752 753 static void 754 separate(const char *s) 755 { 756 diff_output("====%s\n", s); 757 } 758 759 /* 760 * The range of lines rold.from thru rold.to in file i is to be changed. 761 * It is to be printed only if it does not duplicate something to be 762 * printed later. 763 */ 764 static void 765 change(int i, struct range *rold, int fdup) 766 { 767 diff_output("%d:", i); 768 last[i] = rold->to; 769 prange(rold); 770 if (fdup || debug) 771 return; 772 i--; 773 (void)skip(i, rold->from, NULL); 774 (void)skip(i, rold->to, " "); 775 } 776 777 /* 778 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 779 */ 780 static void 781 prange(struct range *rold) 782 { 783 if (rold->to <= rold->from) 784 diff_output("%da\n", rold->from - 1); 785 else { 786 diff_output("%d", rold->from); 787 if (rold->to > rold->from+1) 788 diff_output(",%d", rold->to - 1); 789 diff_output("c\n"); 790 } 791 } 792 793 /* 794 * No difference was reported by diff between file 1 (or 2) and file 3, 795 * and an artificial dummy difference (trange) must be ginned up to 796 * correspond to the change reported in the other file. 797 */ 798 static void 799 keep(int i, struct range *rnew) 800 { 801 int delta; 802 struct range trange; 803 804 delta = last[3] - last[i]; 805 trange.from = rnew->from - delta; 806 trange.to = rnew->to - delta; 807 change(i, &trange, 1); 808 } 809 810 /* 811 * skip to just before line number from in file "i". If "pr" is non-NULL, 812 * print all skipped stuff with string pr as a prefix. 813 */ 814 static int 815 skip(int i, int from, char *pr) 816 { 817 size_t j, n; 818 char *line; 819 820 for (n = 0; cline[i] < from - 1; n += j) { 821 if ((line = getline(fp[i], &j)) == NULL) 822 return (-1); 823 if (pr != NULL) 824 diff_output("%s%s", pr, line); 825 cline[i]++; 826 } 827 return ((int) n); 828 } 829 830 /* 831 * Return 1 or 0 according as the old range (in file 1) contains exactly 832 * the same data as the new range (in file 2). 833 */ 834 static int 835 duplicate(struct range *r1, struct range *r2) 836 { 837 int c,d; 838 int nchar; 839 int nline; 840 841 if (r1->to-r1->from != r2->to-r2->from) 842 return (0); 843 (void)skip(0, r1->from, NULL); 844 (void)skip(1, r2->from, NULL); 845 nchar = 0; 846 for (nline=0; nline < r1->to - r1->from; nline++) { 847 do { 848 c = getc(fp[0]); 849 d = getc(fp[1]); 850 if (c == -1 || d== -1) 851 return (-1); 852 nchar++; 853 if (c != d) { 854 repos(nchar); 855 return (0); 856 } 857 } while (c != '\n'); 858 } 859 repos(nchar); 860 return (1); 861 } 862 863 static void 864 repos(int nchar) 865 { 866 int i; 867 868 for (i = 0; i < 2; i++) 869 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 870 } 871 872 /* 873 * collect an editing script for later regurgitation 874 */ 875 static int 876 edit(struct diff *diff, int fdup, int j) 877 { 878 if (((fdup + 1) & eflag) == 0) 879 return (j); 880 j++; 881 overlap[j] = !fdup; 882 if (!fdup) 883 overlapcnt++; 884 de[j].old.from = diff->old.from; 885 de[j].old.to = diff->old.to; 886 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 887 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 888 return (j); 889 } 890 891 /* regurgitate */ 892 static int 893 edscript(int n) 894 { 895 int j, k; 896 char block[BUFSIZ+1]; 897 898 for (n = n; n > 0; n--) { 899 if (!oflag || !overlap[n]) 900 prange(&de[n].old); 901 else 902 diff_output("%da\n=======\n", de[n].old.to -1); 903 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 904 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 905 j = k > BUFSIZ ? BUFSIZ : k; 906 if (fread(block, 1, (size_t)j, 907 fp[2]) != (size_t)j) 908 return (-1); 909 block[j] = '\0'; 910 diff_output("%s", block); 911 } 912 913 if (!oflag || !overlap[n]) 914 diff_output(".\n"); 915 else { 916 diff_output("%s\n.\n", f3mark); 917 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 918 } 919 } 920 921 return (overlapcnt); 922 } 923 924 static void 925 increase(void) 926 { 927 size_t newsz, incr; 928 929 /* are the memset(3) calls needed? */ 930 newsz = szchanges == 0 ? 64 : 2 * szchanges; 931 incr = newsz - szchanges; 932 933 d13 = xrealloc(d13, newsz, sizeof(*d13)); 934 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 935 d23 = xrealloc(d23, newsz, sizeof(*d23)); 936 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 937 de = xrealloc(de, newsz, sizeof(*de)); 938 memset(de + szchanges, 0, incr * sizeof(*de)); 939 overlap = xrealloc(overlap, newsz, sizeof(*overlap)); 940 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 941 szchanges = newsz; 942 } 943