1 /* $OpenBSD: diff3.c,v 1.65 2021/04/13 14:20:23 stsp 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[PATH_MAX], f3mark[PATH_MAX]; /* 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) == -1) 211 fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno)); 212 if (lseek(fds[3], 0, SEEK_SET) == -1) 213 fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno)); 214 if (lseek(fds[4], 0, SEEK_SET) == -1) 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 free(data); 261 free(patch); 262 263 for (i = 0; i < 3; i++) 264 fclose(fp[i]); 265 266 worklist_run(&temp_files, worklist_unlink); 267 268 free(path1); 269 free(path2); 270 free(path3); 271 free(dp13); 272 free(dp23); 273 } 274 275 static int 276 diff3_internal(int argc, char **argv, const char *fmark, const char *rmark) 277 { 278 size_t m, n; 279 int i; 280 281 eflag = 3; 282 oflag = 1; 283 284 if (argc < 5) 285 return (-1); 286 287 (void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark); 288 (void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark); 289 290 szchanges = 0; 291 memset(last, 0, sizeof(last)); 292 memset(cline, 0, sizeof(cline)); 293 free(d13); 294 free(d23); 295 free(overlap); 296 free(de); 297 298 de = d13 = d23 = NULL; 299 overlap = NULL; 300 301 increase(); 302 303 /* fds[0] and fds[1] are closed in readin() */ 304 m = readin(fds[0], &d13); 305 n = readin(fds[1], &d23); 306 307 for (i = 0; i <= 2; i++) { 308 if ((fp[i] = fdopen(fds[i + 2], "r")) == NULL) { 309 cvs_log(LP_ERR, "%s", argv[i + 2]); 310 return (-1); 311 } 312 } 313 314 return (merge(m, n)); 315 } 316 317 int 318 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines) 319 { 320 char op, *ep; 321 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after; 322 int start, end, i, lineno; 323 u_char tmp; 324 325 dlp = TAILQ_FIRST(&(dlines->l_lines)); 326 lp = TAILQ_FIRST(&(plines->l_lines)); 327 328 end = 0; 329 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL; 330 lp = TAILQ_NEXT(lp, l_list)) { 331 /* Skip blank lines */ 332 if (lp->l_len < 2) 333 continue; 334 335 /* NUL-terminate line buffer for strtol() safety. */ 336 tmp = lp->l_line[lp->l_len - 1]; 337 lp->l_line[lp->l_len - 1] = '\0'; 338 339 op = lp->l_line[strlen(lp->l_line) - 1]; 340 start = (int)strtol(lp->l_line, &ep, 10); 341 342 /* Restore the last byte of the buffer */ 343 lp->l_line[lp->l_len - 1] = tmp; 344 345 if (op == 'a') { 346 if (start > dlines->l_nblines || 347 start < 0 || *ep != 'a') 348 fatal("ed_patch_lines %d", start); 349 } else if (op == 'c') { 350 if (start > dlines->l_nblines || 351 start < 0 || (*ep != ',' && *ep != 'c')) 352 fatal("ed_patch_lines"); 353 354 if (*ep == ',') { 355 ep++; 356 end = (int)strtol(ep, &ep, 10); 357 if (end < 0 || *ep != 'c') 358 fatal("ed_patch_lines"); 359 } else { 360 end = start; 361 } 362 } else { 363 fatal("invalid op %c found while merging", op); 364 } 365 366 367 for (;;) { 368 if (dlp == NULL) 369 break; 370 if (dlp->l_lineno == start) 371 break; 372 if (dlp->l_lineno > start) { 373 dlp = TAILQ_PREV(dlp, tqh, l_list); 374 } else if (dlp->l_lineno < start) { 375 ndlp = TAILQ_NEXT(dlp, l_list); 376 if (ndlp->l_lineno > start) 377 break; 378 dlp = ndlp; 379 } 380 } 381 382 if (dlp == NULL) 383 fatal("ed_patch_lines"); 384 385 386 if (op == 'c') { 387 insert_after = TAILQ_PREV(dlp, tqh, l_list); 388 for (i = 0; i <= (end - start); i++) { 389 ndlp = TAILQ_NEXT(dlp, l_list); 390 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list); 391 dlp = ndlp; 392 } 393 dlp = insert_after; 394 } 395 396 if (op == 'a' || op == 'c') { 397 for (;;) { 398 ndlp = lp; 399 lp = TAILQ_NEXT(lp, l_list); 400 if (lp == NULL) 401 fatal("ed_patch_lines"); 402 403 if (lp->l_len == 2 && 404 lp->l_line[0] == '.' && 405 lp->l_line[1] == '\n') 406 break; 407 408 TAILQ_REMOVE(&(plines->l_lines), lp, l_list); 409 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp, 410 lp, l_list); 411 dlp = lp; 412 413 lp->l_lineno = start; 414 lp = ndlp; 415 } 416 } 417 418 /* 419 * always resort lines as the markers might be put at the 420 * same line as we first started editing. 421 */ 422 lineno = 0; 423 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list) 424 sort->l_lineno = lineno++; 425 dlines->l_nblines = lineno - 1; 426 } 427 428 return (0); 429 } 430 431 /* 432 * Pick up the line numbers of all changes from one change file. 433 * (This puts the numbers in a vector, which is not strictly necessary, 434 * since the vector is processed in one sequential pass. 435 * The vector could be optimized out of existence) 436 */ 437 static size_t 438 readin(int fd, struct diff **dd) 439 { 440 int a, b, c, d; 441 char kind, *p; 442 size_t i; 443 444 fp[0] = fdopen(fd, "r"); 445 if (fp[0] == NULL) 446 fatal("readin: fdopen: %s", strerror(errno)); 447 448 for (i = 0; (p = getchange(fp[0])); i++) { 449 if (i >= szchanges - 1) 450 increase(); 451 a = b = number(&p); 452 if (*p == ',') { 453 p++; 454 b = number(&p); 455 } 456 kind = *p++; 457 c = d = number(&p); 458 if (*p==',') { 459 p++; 460 d = number(&p); 461 } 462 if (kind == 'a') 463 a++; 464 if (kind == 'd') 465 c++; 466 b++; 467 d++; 468 (*dd)[i].old.from = a; 469 (*dd)[i].old.to = b; 470 (*dd)[i].new.from = c; 471 (*dd)[i].new.to = d; 472 } 473 474 if (i) { 475 (*dd)[i].old.from = (*dd)[i-1].old.to; 476 (*dd)[i].new.from = (*dd)[i-1].new.to; 477 } 478 479 (void)fclose(fp[0]); 480 481 return (i); 482 } 483 484 static int 485 number(char **lc) 486 { 487 int nn; 488 489 nn = 0; 490 while (isdigit((unsigned char)(**lc))) 491 nn = nn*10 + *(*lc)++ - '0'; 492 493 return (nn); 494 } 495 496 static char * 497 getchange(FILE *b) 498 { 499 char *line; 500 501 while ((line = get_line(b, NULL))) { 502 if (isdigit((unsigned char)line[0])) 503 return (line); 504 } 505 506 return (NULL); 507 } 508 509 static char * 510 get_line(FILE *b, size_t *n) 511 { 512 char *cp; 513 size_t len; 514 static char *buf; 515 static size_t bufsize; 516 517 if ((cp = fgetln(b, &len)) == NULL) 518 return (NULL); 519 520 if (cp[len - 1] != '\n') 521 len++; 522 if (len + 1 > bufsize) { 523 do { 524 bufsize += 1024; 525 } while (len + 1 > bufsize); 526 buf = xreallocarray(buf, 1, bufsize); 527 } 528 memcpy(buf, cp, len - 1); 529 buf[len - 1] = '\n'; 530 buf[len] = '\0'; 531 if (n != NULL) 532 *n = len; 533 534 return (buf); 535 } 536 537 static int 538 merge(size_t m1, size_t m2) 539 { 540 struct diff *d1, *d2, *d3; 541 int dpl, j, t1, t2; 542 543 d1 = d13; 544 d2 = d23; 545 j = 0; 546 for (;;) { 547 t1 = (d1 < d13 + m1); 548 t2 = (d2 < d23 + m2); 549 if (!t1 && !t2) 550 break; 551 552 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 break; 748 if (c == -1 || d== -1) 749 return (-1); 750 nchar++; 751 if (c != d) { 752 repos(nchar); 753 return (0); 754 } 755 } while (c != '\n'); 756 } 757 repos(nchar); 758 return (1); 759 } 760 761 static void 762 repos(int nchar) 763 { 764 int i; 765 766 for (i = 0; i < 2; i++) 767 (void)fseek(fp[i], (long)-nchar, SEEK_CUR); 768 } 769 770 /* 771 * collect an editing script for later regurgitation 772 */ 773 static int 774 edit(struct diff *diff, int fdup, int j) 775 { 776 if (((fdup + 1) & eflag) == 0) 777 return (j); 778 j++; 779 overlap[j] = !fdup; 780 if (!fdup) 781 overlapcnt++; 782 de[j].old.from = diff->old.from; 783 de[j].old.to = diff->old.to; 784 de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL); 785 de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL); 786 return (j); 787 } 788 789 /* regurgitate */ 790 static int 791 edscript(int n) 792 { 793 int j, k; 794 char block[BUFSIZ+1]; 795 796 for (; n > 0; n--) { 797 if (!oflag || !overlap[n]) 798 prange(&de[n].old); 799 else 800 diff_output("%da\n=======\n", de[n].old.to -1); 801 (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET); 802 for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) { 803 size_t r; 804 j = k > BUFSIZ ? BUFSIZ : k; 805 r = fread(block, 1, j, fp[2]); 806 if (r == 0) { 807 if (feof(fp[2])) 808 break; 809 return (-1); 810 } 811 if (r != (size_t)j) 812 j = r; 813 block[j] = '\0'; 814 diff_output("%s", block); 815 } 816 817 if (!oflag || !overlap[n]) 818 diff_output(".\n"); 819 else { 820 diff_output("%s\n.\n", f3mark); 821 diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark); 822 } 823 } 824 825 return (overlapcnt); 826 } 827 828 static void 829 increase(void) 830 { 831 size_t newsz, incr; 832 833 /* are the memset(3) calls needed? */ 834 newsz = szchanges == 0 ? 64 : 2 * szchanges; 835 incr = newsz - szchanges; 836 837 d13 = xreallocarray(d13, newsz, sizeof(*d13)); 838 memset(d13 + szchanges, 0, incr * sizeof(*d13)); 839 d23 = xreallocarray(d23, newsz, sizeof(*d23)); 840 memset(d23 + szchanges, 0, incr * sizeof(*d23)); 841 de = xreallocarray(de, newsz, sizeof(*de)); 842 memset(de + szchanges, 0, incr * sizeof(*de)); 843 overlap = xreallocarray(overlap, newsz, sizeof(*overlap)); 844 memset(overlap + szchanges, 0, incr * sizeof(*overlap)); 845 szchanges = newsz; 846 } 847