1 /* $OpenBSD: diff3.c,v 1.55 2012/03/04 04:05:15 fgsch 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 <errno.h> 69 #include <fcntl.h> 70 #include <stdio.h> 71 #include <stdlib.h> 72 #include <string.h> 73 #include <unistd.h> 74 75 #include "atomicio.h" 76 #include "cvs.h" 77 #include "diff.h" 78 79 /* diff3 - 3-way differential file comparison */ 80 81 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3] 82 * 83 * d13 = diff report on f1 vs f3 84 * d23 = diff report on f2 vs f3 85 * f1, f2, f3 the 3 files 86 * if changes in f1 overlap with changes in f3, m1 and m3 are used 87 * to mark the overlaps; otherwise, the file names f1 and f3 are used 88 * (only for options E and X). 89 */ 90 91 /* 92 * "from" is first in range of changed lines; "to" is last+1 93 * from=to=line after point of insertion for added lines. 94 */ 95 struct range { 96 int from; 97 int to; 98 }; 99 100 struct diff { 101 struct range old; 102 struct range new; 103 }; 104 105 static size_t szchanges; 106 107 static struct diff *d13; 108 static struct diff *d23; 109 110 /* 111 * "de" is used to gather editing scripts. These are later spewed out in 112 * reverse order. Its first element must be all zero, the "new" component 113 * of "de" contains line positions or byte positions depending on when you 114 * look (!?). Array overlap indicates which sections in "de" correspond to 115 * lines that are different in all three files. 116 */ 117 static struct diff *de; 118 static char *overlap; 119 static int overlapcnt = 0; 120 static FILE *fp[3]; 121 static int cline[3]; /* # of the last-read line in each file (0-2) */ 122 123 /* 124 * the latest known correspondence between line numbers of the 3 files 125 * is stored in last[1-3]; 126 */ 127 static int last[4]; 128 static int eflag; 129 static int oflag; /* indicates whether to mark overlaps (-E or -X)*/ 130 static int debug = 0; 131 static char f1mark[MAXPATHLEN], f3mark[MAXPATHLEN]; /* markers for -E and -X */ 132 133 static int duplicate(struct range *, struct range *); 134 static int edit(struct diff *, int, int); 135 static char *getchange(FILE *); 136 static char *get_line(FILE *, size_t *); 137 static int number(char **); 138 static size_t readin(int, struct diff **); 139 static int skip(int, int, char *); 140 static int edscript(int); 141 static int merge(size_t, size_t); 142 static void change(int, struct range *, int); 143 static void keep(int, struct range *); 144 static void prange(struct range *); 145 static void repos(int); 146 static void separate(const char *); 147 static void increase(void); 148 static int diff3_internal(int, char **, const char *, const char *); 149 150 int diff3_conflicts = 0; 151 RCSNUM *d3rev1 = NULL; 152 RCSNUM *d3rev2 = NULL; 153 154 static int fds[5]; 155 156 void 157 cvs_merge_file(struct cvs_file *cf, int verbose) 158 { 159 int i, argc; 160 char *data, *patch; 161 char *argv[5], r1[CVS_REV_BUFSZ], r2[CVS_REV_BUFSZ]; 162 char *dp13, *dp23, *path1, *path2, *path3; 163 BUF *b1, *d1, *d2, *diffb; 164 size_t dlen, plen; 165 struct rcs_line *lp; 166 struct rcs_lines *dlines, *plines; 167 168 overlapcnt = 0; 169 b1 = d1 = d2 = diffb = NULL; 170 171 rcsnum_tostr(d3rev1, r1, sizeof(r1)); 172 rcsnum_tostr(d3rev2, r2, sizeof(r2)); 173 174 b1 = buf_load_fd(cf->fd); 175 d1 = buf_alloc(128); 176 d2 = buf_alloc(128); 177 diffb = buf_alloc(128); 178 179 (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir); 180 (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir); 181 (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir); 182 183 fds[2] = buf_write_stmp(b1, path1, NULL); 184 if (verbose == 1) 185 cvs_printf("Retrieving revision %s\n", r1); 186 fds[3] = rcs_rev_write_stmp(cf->file_rcs, d3rev1, path2, 0); 187 if (verbose == 1) 188 cvs_printf("Retrieving revision %s\n", r2); 189 fds[4] = rcs_rev_write_stmp(cf->file_rcs, d3rev2, path3, 0); 190 191 diffreg(path1, path3, fds[2], fds[4], d1, D_FORCEASCII); 192 diffreg(path2, path3, fds[3], fds[4], d2, D_FORCEASCII); 193 194 (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir); 195 fds[0] = buf_write_stmp(d1, dp13, NULL); 196 buf_free(d1); 197 198 (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir); 199 fds[1] = buf_write_stmp(d2, dp23, NULL); 200 buf_free(d2); 201 202 argc = 0; 203 diffbuf = diffb; 204 argv[argc++] = dp13; 205 argv[argc++] = dp23; 206 argv[argc++] = path1; 207 argv[argc++] = path2; 208 argv[argc++] = path3; 209 210 if (lseek(fds[2], 0, SEEK_SET) < 0) 211 fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno)); 212 if (lseek(fds[3], 0, SEEK_SET) < 0) 213 fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno)); 214 if (lseek(fds[4], 0, SEEK_SET) < 0) 215 fatal("cvs_merge_file: lseek fds[4]: %s", strerror(errno)); 216 217 diff3_conflicts = diff3_internal(argc, argv, cf->file_path, r2); 218 if (diff3_conflicts < 0) 219 fatal("cvs_merge_file: merging failed for an unknown reason"); 220 221 plen = buf_len(diffb); 222 patch = buf_release(diffb); 223 dlen = buf_len(b1); 224 data = buf_release(b1); 225 226 if (verbose == 1) 227 cvs_printf("Merging differences between %s and %s into `%s'\n", 228 r1, r2, cf->file_path); 229 230 dlines = cvs_splitlines(data, dlen); 231 plines = cvs_splitlines(patch, plen); 232 233 ed_patch_lines(dlines, plines); 234 cvs_freelines(plines); 235 236 if (verbose == 1 && diff3_conflicts != 0) { 237 cvs_log(LP_ERR, "%d conflict%s found during merge, " 238 "please correct.", diff3_conflicts, 239 (diff3_conflicts > 1) ? "s" : ""); 240 } 241 242 (void)close(cf->fd); 243 cf->fd = open(cf->file_path, O_CREAT | O_RDWR | O_TRUNC, 0644); 244 if (cf->fd == -1) { 245 fatal("cvs_merge_file: failed to reopen fd for writing: %s", 246 strerror(errno)); 247 } 248 249 TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) { 250 if (lp->l_line == NULL) 251 continue; 252 253 if (atomicio(vwrite, cf->fd, lp->l_line, lp->l_len) != 254 lp->l_len) 255 fatal("cvs_merge_file: %s", strerror(errno)); 256 } 257 258 cvs_freelines(dlines); 259 260 if (data != NULL) 261 xfree(data); 262 xfree(patch); 263 264 for (i = 0; i < 3; i++) 265 fclose(fp[i]); 266 267 worklist_run(&temp_files, worklist_unlink); 268 269 xfree(path1); 270 xfree(path2); 271 xfree(path3); 272 xfree(dp13); 273 xfree(dp23); 274 } 275 276 static int 277 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 278 { 279 size_t m, n; 280 int i; 281 282 eflag = 3; 283 oflag = 1; 284 285 if (argc < 5) 286 return (-1); 287 288 (void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 289 (void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 290 291 szchanges = 0; 292 memset(last, 0, sizeof(last)); 293 memset(cline, 0, sizeof(cline)); 294 if (d13 != NULL) 295 xfree(d13); 296 if (d23 != NULL) 297 xfree(d23); 298 if (overlap != NULL) 299 xfree(overlap); 300 if (de != NULL) 301 xfree(de); 302 303 overlap = NULL; 304 de = d13 = d23 = NULL; 305 306 increase(); 307 308 /* fds[0] and fds[1] are closed in readin() */ 309 m = readin(fds[0], &d13); 310 n = readin(fds[1], &d23); 311 312 for (i = 0; i <= 2; i++) { 313 if ((fp[i] = fdopen(fds[i + 2], "r")) == NULL) { 314 cvs_log(LP_ERR, "%s", argv[i + 2]); 315 return (-1); 316 } 317 } 318 319 return (merge(m, n)); 320 } 321 322 int 323 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 324 { 325 char op, *ep; 326 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 327 int start, end, i, lineno; 328 u_char tmp; 329 330 dlp = TAILQ_FIRST(&(dlines->l_lines)); 331 lp = TAILQ_FIRST(&(plines->l_lines)); 332 333 end = 0; 334 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 335 lp = TAILQ_NEXT(lp, l_list)) { 336 /* Skip blank lines */ 337 if (lp->l_len < 2) 338 continue; 339 340 /* NUL-terminate line buffer for strtol() safety. */ 341 tmp = lp->l_line[lp->l_len - 1]; 342 lp->l_line[lp->l_len - 1] = '\0'; 343 344 op = lp->l_line[strlen(lp->l_line) - 1]; 345 start = (int)strtol(lp->l_line, &ep, 10); 346 347 /* Restore the last byte of the buffer */ 348 lp->l_line[lp->l_len - 1] = tmp; 349 350 if (op == 'a') { 351 if (start > dlines->l_nblines || 352 start < 0 || *ep != 'a') 353 fatal("ed_patch_lines %d", start); 354 } else if (op == 'c') { 355 if (start > dlines->l_nblines || 356 start < 0 || (*ep != ',' && *ep != 'c')) 357 fatal("ed_patch_lines"); 358 359 if (*ep == ',') { 360 ep++; 361 end = (int)strtol(ep, &ep, 10); 362 if (end < 0 || *ep != 'c') 363 fatal("ed_patch_lines"); 364 } else { 365 end = start; 366 } 367 } else { 368 fatal("invalid op %c found while merging", op); 369 } 370 371 372 for (;;) { 373 if (dlp == NULL) 374 break; 375 if (dlp->l_lineno == start) 376 break; 377 if (dlp->l_lineno > start) { 378 dlp = TAILQ_PREV(dlp, tqh, l_list); 379 } else if (dlp->l_lineno < start) { 380 ndlp = TAILQ_NEXT(dlp, l_list); 381 if (ndlp->l_lineno > start) 382 break; 383 dlp = ndlp; 384 } 385 } 386 387 if (dlp == NULL) 388 fatal("ed_patch_lines"); 389 390 391 if (op == 'c') { 392 insert_after = TAILQ_PREV(dlp, tqh, l_list); 393 for (i = 0; i <= (end - start); i++) { 394 ndlp = TAILQ_NEXT(dlp, l_list); 395 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 396 dlp = ndlp; 397 } 398 dlp = insert_after; 399 } 400 401 if (op == 'a' || op == 'c') { 402 for (;;) { 403 ndlp = lp; 404 lp = TAILQ_NEXT(lp, l_list); 405 if (lp == NULL) 406 fatal("ed_patch_lines"); 407 408 if (lp->l_len == 2 && 409 lp->l_line[0] == '.' && 410 lp->l_line[1] == '\n') 411 break; 412 413 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 414 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 415 lp, l_list); 416 dlp = lp; 417 418 lp->l_lineno = start; 419 lp = ndlp; 420 } 421 } 422 423 /* 424 * always resort lines as the markers might be put at the 425 * same line as we first started editing. 426 */ 427 lineno = 0; 428 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 429 sort->l_lineno = lineno++; 430 dlines->l_nblines = lineno - 1; 431 } 432 433 return (0); 434 } 435 436 /* 437 * Pick up the line numbers of all changes from one change file. 438 * (This puts the numbers in a vector, which is not strictly necessary, 439 * since the vector is processed in one sequential pass. 440 * The vector could be optimized out of existence) 441 */ 442 static size_t 443 readin(int fd, struct diff **dd) 444 { 445 int a, b, c, d; 446 char kind, *p; 447 size_t i; 448 449 fp[0] = fdopen(fd, "r"); 450 if (fp[0] == NULL) 451 fatal("readin: fdopen: %s", strerror(errno)); 452 453 for (i = 0; (p = getchange(fp[0])); i++) { 454 if (i >= szchanges - 1) 455 increase(); 456 a = b = number(&p); 457 if (*p == ',') { 458 p++; 459 b = number(&p); 460 } 461 kind = *p++; 462 c = d = number(&p); 463 if (*p==',') { 464 p++; 465 d = number(&p); 466 } 467 if (kind == 'a') 468 a++; 469 if (kind == 'd') 470 c++; 471 b++; 472 d++; 473 (*dd)[i].old.from = a; 474 (*dd)[i].old.to = b; 475 (*dd)[i].new.from = c; 476 (*dd)[i].new.to = d; 477 } 478 479 if (i) { 480 (*dd)[i].old.from = (*dd)[i-1].old.to; 481 (*dd)[i].new.from = (*dd)[i-1].new.to; 482 } 483 484 (void)fclose(fp[0]); 485 486 return (i); 487 } 488 489 static int 490 number(char **lc) 491 { 492 int nn; 493 494 nn = 0; 495 while (isdigit((unsigned char)(**lc))) 496 nn = nn*10 + *(*lc)++ - '0'; 497 498 return (nn); 499 } 500 501 static char * 502 getchange(FILE *b) 503 { 504 char *line; 505 506 while ((line = get_line(b, NULL))) { 507 if (isdigit((unsigned char)line[0])) 508 return (line); 509 } 510 511 return (NULL); 512 } 513 514 static char * 515 get_line(FILE *b, size_t *n) 516 { 517 char *cp; 518 size_t len; 519 static char *buf; 520 static size_t bufsize; 521 522 if ((cp = fgetln(b, &len)) == NULL) 523 return (NULL); 524 525 if (cp[len - 1] != '\n') 526 len++; 527 if (len + 1 > bufsize) { 528 do { 529 bufsize += 1024; 530 } while (len + 1 > bufsize); 531 buf = xrealloc(buf, 1, bufsize); 532 } 533 memcpy(buf, cp, len - 1); 534 buf[len - 1] = '\n'; 535 buf[len] = '\0'; 536 if (n != NULL) 537 *n = len; 538 539 return (buf); 540 } 541 542 static int 543 merge(size_t m1, size_t m2) 544 { 545 struct diff *d1, *d2, *d3; 546 int dpl, j, t1, t2; 547 548 d1 = d13; 549 d2 = d23; 550 j = 0; 551 while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) { 552 if (debug) { 553 printf("%d,%d=%d,%d %d,%d=%d,%d\n", 554 d1->old.from, d1->old.to, 555 d1->new.from, d1->new.to, 556 d2->old.from, d2->old.to, 557 d2->new.from, d2->new.to); 558 } 559 560 /* first file is different from others */ 561 if (!t2 || (t1 && d1->new.to < d2->new.from)) { 562 /* stuff peculiar to 1st file */ 563 if (eflag==0) { 564 separate("1"); 565 change(1, &d1->old, 0); 566 keep(2, &d1->new); 567 change(3, &d1->new, 0); 568 } 569 d1++; 570 continue; 571 } 572 573 /* second file is different from others */ 574 if (!t1 || (t2 && d2->new.to < d1->new.from)) { 575 if (eflag==0) { 576 separate("2"); 577 keep(1, &d2->new); 578 change(2, &d2->old, 0); 579 change(3, &d2->new, 0); 580 } 581 d2++; 582 continue; 583 } 584 585 /* 586 * Merge overlapping changes in first file 587 * this happens after extension (see below). 588 */ 589 if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) { 590 d1[1].old.from = d1->old.from; 591 d1[1].new.from = d1->new.from; 592 d1++; 593 continue; 594 } 595 596 /* merge overlapping changes in second */ 597 if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) { 598 d2[1].old.from = d2->old.from; 599 d2[1].new.from = d2->new.from; 600 d2++; 601 continue; 602 } 603 /* stuff peculiar to third file or different in all */ 604 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) { 605 dpl = duplicate(&d1->old,&d2->old); 606 if (dpl == -1) 607 return (-1); 608 609 /* 610 * dpl = 0 means all files differ 611 * dpl = 1 means files 1 and 2 identical 612 */ 613 if (eflag==0) { 614 separate(dpl ? "3" : ""); 615 change(1, &d1->old, dpl); 616 change(2, &d2->old, 0); 617 d3 = d1->old.to > d1->old.from ? d1 : d2; 618 change(3, &d3->new, 0); 619 } else 620 j = edit(d1, dpl, j); 621 d1++; 622 d2++; 623 continue; 624 } 625 626 /* 627 * Overlapping changes from file 1 and 2; extend changes 628 * appropriately to make them coincide. 629 */ 630 if (d1->new.from < d2->new.from) { 631 d2->old.from -= d2->new.from-d1->new.from; 632 d2->new.from = d1->new.from; 633 } else if (d2->new.from < d1->new.from) { 634 d1->old.from -= d1->new.from-d2->new.from; 635 d1->new.from = d2->new.from; 636 } 637 if (d1->new.to > d2->new.to) { 638 d2->old.to += d1->new.to - d2->new.to; 639 d2->new.to = d1->new.to; 640 } else if (d2->new.to > d1->new.to) { 641 d1->old.to += d2->new.to - d1->new.to; 642 d1->new.to = d2->new.to; 643 } 644 } 645 646 return (edscript(j)); 647 } 648 649 static void 650 separate(const char *s) 651 { 652 diff_output("====%s\n", s); 653 } 654 655 /* 656 * The range of lines rold.from thru rold.to in file i is to be changed. 657 * It is to be printed only if it does not duplicate something to be 658 * printed later. 659 */ 660 static void 661 change(int i, struct range *rold, int fdup) 662 { 663 diff_output("%d:", i); 664 last[i] = rold->to; 665 prange(rold); 666 if (fdup || debug) 667 return; 668 i--; 669 (void)skip(i, rold->from, NULL); 670 (void)skip(i, rold->to, " "); 671 } 672 673 /* 674 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1 675 */ 676 static void 677 prange(struct range *rold) 678 { 679 if (rold->to <= rold->from) 680 diff_output("%da\n", rold->from - 1); 681 else { 682 diff_output("%d", rold->from); 683 if (rold->to > rold->from+1) 684 diff_output(",%d", rold->to - 1); 685 diff_output("c\n"); 686 } 687 } 688 689 /* 690 * No difference was reported by diff between file 1 (or 2) and file 3, 691 * and an artificial dummy difference (trange) must be ginned up to 692 * correspond to the change reported in the other file. 693 */ 694 static void 695 keep(int i, struct range *rnew) 696 { 697 int delta; 698 struct range trange; 699 700 delta = last[3] - last[i]; 701 trange.from = rnew->from - delta; 702 trange.to = rnew->to - delta; 703 change(i, &trange, 1); 704 } 705 706 /* 707 * skip to just before line number from in file "i". If "pr" is non-NULL, 708 * print all skipped stuff with string pr as a prefix. 709 */ 710 static int 711 skip(int i, int from, char *pr) 712 { 713 size_t j, n; 714 char *line; 715 716 for (n = 0; cline[i] < from - 1; n += j) { 717 if ((line = get_line(fp[i], &j)) == NULL) 718 return (-1); 719 if (pr != NULL) 720 diff_output("%s%s", pr, line); 721 cline[i]++; 722 } 723 return ((int) n); 724 } 725 726 /* 727 * Return 1 or 0 according as the old range (in file 1) contains exactly 728 * the same data as the new range (in file 2). 729 */ 730 static int 731 duplicate(struct range *r1, struct range *r2) 732 { 733 int c,d; 734 int nchar; 735 int nline; 736 737 if (r1->to-r1->from != r2->to-r2->from) 738 return (0); 739 (void)skip(0, r1->from, NULL); 740 (void)skip(1, r2->from, NULL); 741 nchar = 0; 742 for (nline=0; nline < r1->to - r1->from; nline++) { 743 do { 744 c = getc(fp[0]); 745 d = getc(fp[1]); 746 if (c == -1 || d== -1) 747 return (-1); 748 nchar++; 749 if (c != d) { 750 repos(nchar); 751 return (0); 752 } 753 } while (c != '\n'); 754 } 755 repos(nchar); 756 return (1); 757 } 758 759 static void 760 repos(int nchar) 761 { 762 int i; 763 764 for (i = 0; i < 2; i++) 765 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 766 } 767 768 /* 769 * collect an editing script for later regurgitation 770 */ 771 static int 772 edit(struct diff *diff, int fdup, int j) 773 { 774 if (((fdup + 1) & eflag) == 0) 775 return (j); 776 j++; 777 overlap[j] = !fdup; 778 if (!fdup) 779 overlapcnt++; 780 de[j].old.from = diff->old.from; 781 de[j].old.to = diff->old.to; 782 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 783 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 784 return (j); 785 } 786 787 /* regurgitate */ 788 static int 789 edscript(int n) 790 { 791 int j, k; 792 char block[BUFSIZ+1]; 793 794 for (n = n; n > 0; n--) { 795 if (!oflag || !overlap[n]) 796 prange(&de[n].old); 797 else 798 diff_output("%da\n=======\n", de[n].old.to -1); 799 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 800 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 801 j = k > BUFSIZ ? BUFSIZ : k; 802 if (fread(block, 1, j, fp[2]) != j) 803 return (-1); 804 block[j] = '\0'; 805 diff_output("%s", block); 806 } 807 808 if (!oflag || !overlap[n]) 809 diff_output(".\n"); 810 else { 811 diff_output("%s\n.\n", f3mark); 812 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 813 } 814 } 815 816 return (overlapcnt); 817 } 818 819 static void 820 increase(void) 821 { 822 size_t newsz, incr; 823 824 /* are the memset(3) calls needed? */ 825 newsz = szchanges == 0 ? 64 : 2 * szchanges; 826 incr = newsz - szchanges; 827 828 d13 = xrealloc(d13, newsz, sizeof(*d13)); 829 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 830 d23 = xrealloc(d23, newsz, sizeof(*d23)); 831 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 832 de = xrealloc(de, newsz, sizeof(*de)); 833 memset(de + szchanges, 0, incr * sizeof(*de)); 834 overlap = xrealloc(overlap, newsz, sizeof(*overlap)); 835 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 836 szchanges = newsz; 837 } 838