Annotation of src/usr.bin/rcs/diff3.c, Revision 1.1
1.1 ! joris 1: /* $OpenBSD: diff3.c,v 1.23 2006/04/14 02:49:41 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: #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 1.23 2006/04/14 02:49:41 deraadt Exp $";
! 76: #endif /* not lint */
! 77:
! 78: #include "includes.h"
! 79:
! 80: #include "diff.h"
! 81: #include "util.h"
! 82: #include "xmalloc.h"
! 83:
! 84: /* diff3 - 3-way differential file comparison */
! 85:
! 86: /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
! 87: *
! 88: * d13 = diff report on f1 vs f3
! 89: * d23 = diff report on f2 vs f3
! 90: * f1, f2, f3 the 3 files
! 91: * if changes in f1 overlap with changes in f3, m1 and m3 are used
! 92: * to mark the overlaps; otherwise, the file names f1 and f3 are used
! 93: * (only for options E and X).
! 94: */
! 95:
! 96: /*
! 97: * "from" is first in range of changed lines; "to" is last+1
! 98: * from=to=line after point of insertion for added lines.
! 99: */
! 100: struct range {
! 101: int from;
! 102: int to;
! 103: };
! 104:
! 105: struct diff {
! 106: struct range old;
! 107: struct range new;
! 108: };
! 109:
! 110: static size_t szchanges;
! 111:
! 112: static struct diff *d13;
! 113: static struct diff *d23;
! 114:
! 115: /*
! 116: * "de" is used to gather editing scripts. These are later spewed out in
! 117: * reverse order. Its first element must be all zero, the "new" component
! 118: * of "de" contains line positions or byte positions depending on when you
! 119: * look (!?). Array overlap indicates which sections in "de" correspond to
! 120: * lines that are different in all three files.
! 121: */
! 122: static struct diff *de;
! 123: static char *overlap;
! 124: static int overlapcnt = 0;
! 125: static FILE *fp[3];
! 126: static int cline[3]; /* # of the last-read line in each file (0-2) */
! 127:
! 128: /*
! 129: * the latest known correspondence between line numbers of the 3 files
! 130: * is stored in last[1-3];
! 131: */
! 132: static int last[4];
! 133: static int eflag;
! 134: static int oflag; /* indicates whether to mark overlaps (-E or -X)*/
! 135: static int debug = 0;
! 136: static char f1mark[40], f3mark[40]; /* markers for -E and -X */
! 137:
! 138: static int duplicate(struct range *, struct range *);
! 139: static int edit(struct diff *, int, int);
! 140: static char *getchange(FILE *);
! 141: static char *getline(FILE *, size_t *);
! 142: static int number(char **);
! 143: static size_t readin(char *, struct diff **);
! 144: static int skip(int, int, char *);
! 145: static int edscript(int);
! 146: static int merge(size_t, size_t);
! 147: static void change(int, struct range *, int);
! 148: static void keep(int, struct range *);
! 149: static void prange(struct range *);
! 150: static void repos(int);
! 151: static void separate(const char *);
! 152: static void increase(void);
! 153: static int diff3_internal(int, char **, const char *, const char *);
! 154:
! 155: int diff3_conflicts = 0;
! 156:
! 157: BUF *
! 158: rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int verbose)
! 159: {
! 160: int argc;
! 161: char *data, *patch;
! 162: char *argv[5], r1[16], r2[16];
! 163: char path1[MAXPATHLEN], path2[MAXPATHLEN], path3[MAXPATHLEN];
! 164: char dp13[MAXPATHLEN], dp23[MAXPATHLEN];
! 165: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
! 166:
! 167: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
! 168:
! 169: rcsnum_tostr(rev1, r1, sizeof(r1));
! 170: rcsnum_tostr(rev2, r2, sizeof(r2));
! 171:
! 172: if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
! 173: goto out;
! 174:
! 175: if (verbose == 1)
! 176: printf("Retrieving revision %s\n", r1);
! 177: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
! 178: goto out;
! 179:
! 180: if (verbose == 1)
! 181: printf("Retrieving revision %s\n", r2);
! 182: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
! 183: goto out;
! 184:
! 185: d1 = rcs_buf_alloc((size_t)128, BUF_AUTOEXT);
! 186: d2 = rcs_buf_alloc((size_t)128, BUF_AUTOEXT);
! 187: diffb = rcs_buf_alloc((size_t)128, BUF_AUTOEXT);
! 188:
! 189: strlcpy(path1, "/tmp/diff1.XXXXXXXXXX", sizeof(path1));
! 190: rcs_buf_write_stmp(b1, path1, 0600);
! 191:
! 192: strlcpy(path2, "/tmp/diff2.XXXXXXXXXX", sizeof(path2));
! 193: rcs_buf_write_stmp(b2, path2, 0600);
! 194:
! 195: strlcpy(path3, "/tmp/diff3.XXXXXXXXXX", sizeof(path3));
! 196: rcs_buf_write_stmp(b3, path3, 0600);
! 197:
! 198: rcs_buf_free(b2);
! 199: b2 = NULL;
! 200:
! 201: rcs_diffreg(path1, path3, d1);
! 202: rcs_diffreg(path2, path3, d2);
! 203:
! 204: strlcpy(dp13, "/tmp/d13.XXXXXXXXXX", sizeof(dp13));
! 205: rcs_buf_write_stmp(d1, dp13, 0600);
! 206:
! 207: rcs_buf_free(d1);
! 208: d1 = NULL;
! 209:
! 210: strlcpy(dp23, "/tmp/d23.XXXXXXXXXX", sizeof(dp23));
! 211: rcs_buf_write_stmp(d2, dp23, 0600);
! 212:
! 213: rcs_buf_free(d2);
! 214: d2 = NULL;
! 215:
! 216: argc = 0;
! 217: diffbuf = diffb;
! 218: argv[argc++] = dp13;
! 219: argv[argc++] = dp23;
! 220: argv[argc++] = path1;
! 221: argv[argc++] = path2;
! 222: argv[argc++] = path3;
! 223:
! 224: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
! 225: if (diff3_conflicts < 0) {
! 226: rcs_buf_free(diffb);
! 227: diffb = NULL;
! 228: goto out;
! 229: }
! 230:
! 231: rcs_buf_putc(diffb, '\0');
! 232: rcs_buf_putc(b1, '\0');
! 233:
! 234: patch = rcs_buf_release(diffb);
! 235: data = rcs_buf_release(b1);
! 236: diffb = b1 = NULL;
! 237:
! 238: if ((diffb = rcs_patchfile(data, patch, ed_patch_lines)) == NULL)
! 239: goto out;
! 240:
! 241: if (verbose == 1 && diff3_conflicts != 0) {
! 242: warnx("%d conflict%s found during merge, "
! 243: "please correct.", diff3_conflicts,
! 244: (diff3_conflicts > 1) ? "s" : "");
! 245: }
! 246:
! 247: xfree(data);
! 248: xfree(patch);
! 249:
! 250: out:
! 251: if (b1 != NULL)
! 252: rcs_buf_free(b1);
! 253: if (b2 != NULL)
! 254: rcs_buf_free(b2);
! 255: if (b3 != NULL)
! 256: rcs_buf_free(b3);
! 257: if (d1 != NULL)
! 258: rcs_buf_free(d1);
! 259: if (d2 != NULL)
! 260: rcs_buf_free(d2);
! 261:
! 262: (void)unlink(path1);
! 263: (void)unlink(path2);
! 264: (void)unlink(path3);
! 265: (void)unlink(dp13);
! 266: (void)unlink(dp23);
! 267:
! 268: return (diffb);
! 269: }
! 270:
! 271: static int
! 272: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
! 273: {
! 274: size_t m, n;
! 275: int i;
! 276:
! 277: /* XXX */
! 278: eflag = 3;
! 279: oflag = 1;
! 280:
! 281: if (argc < 5)
! 282: return (-1);
! 283:
! 284: strlcpy(f1mark, "<<<<<<< ", sizeof(f1mark));
! 285: strlcat(f1mark, fmark, sizeof(f1mark));
! 286:
! 287: strlcpy(f3mark, ">>>>>>> ", sizeof(f3mark));
! 288: strlcat(f3mark, rmark, sizeof(f3mark));
! 289:
! 290: increase();
! 291: m = readin(argv[0], &d13);
! 292: n = readin(argv[1], &d23);
! 293:
! 294: for (i = 0; i <= 2; i++) {
! 295: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
! 296: warn("%s", argv[i + 2]);
! 297: return (-1);
! 298: }
! 299: }
! 300:
! 301: return (merge(m, n));
! 302: }
! 303:
! 304: int
! 305: ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
! 306: {
! 307: char op, *ep;
! 308: struct rcs_line *sort, *lp, *dlp, *ndlp;
! 309: int start, end, i, lineno;
! 310:
! 311: dlp = TAILQ_FIRST(&(dlines->l_lines));
! 312: lp = TAILQ_FIRST(&(plines->l_lines));
! 313:
! 314: end = 0;
! 315: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
! 316: lp = TAILQ_NEXT(lp, l_list)) {
! 317: op = lp->l_line[strlen(lp->l_line) - 1];
! 318: start = (int)strtol(lp->l_line, &ep, 10);
! 319: if (op == 'a') {
! 320: if (start > dlines->l_nblines ||
! 321: start < 0 || *ep != 'a')
! 322: errx(1, "ed_patch_lines");
! 323: } else if (op == 'c') {
! 324: if (start > dlines->l_nblines ||
! 325: start < 0 || (*ep != ',' && *ep != 'c'))
! 326: errx(1, "ed_patch_lines");
! 327:
! 328: if (*ep == ',') {
! 329: ep++;
! 330: end = (int)strtol(ep, &ep, 10);
! 331: if (end < 0 || *ep != 'c')
! 332: errx(1, "ed_patch_lines");
! 333: } else {
! 334: end = start;
! 335: }
! 336: }
! 337:
! 338:
! 339: for (;;) {
! 340: if (dlp == NULL)
! 341: break;
! 342: if (dlp->l_lineno == start)
! 343: break;
! 344: if (dlp->l_lineno > start) {
! 345: dlp = TAILQ_PREV(dlp, rcs_tqh, l_list);
! 346: } else if (dlp->l_lineno < start) {
! 347: ndlp = TAILQ_NEXT(dlp, l_list);
! 348: if (ndlp->l_lineno > start)
! 349: break;
! 350: dlp = ndlp;
! 351: }
! 352: }
! 353:
! 354: if (dlp == NULL)
! 355: errx(1, "ed_patch_lines");
! 356:
! 357:
! 358: if (op == 'c') {
! 359: for (i = 0; i <= (end - start); i++) {
! 360: ndlp = TAILQ_NEXT(dlp, l_list);
! 361: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
! 362: dlp = ndlp;
! 363: }
! 364: dlp = TAILQ_PREV(dlp, rcs_tqh, l_list);
! 365: }
! 366:
! 367: if (op == 'a' || op == 'c') {
! 368: for (;;) {
! 369: ndlp = lp;
! 370: lp = TAILQ_NEXT(lp, l_list);
! 371: if (lp == NULL)
! 372: errx(1, "ed_patch_lines");
! 373:
! 374: if (!strcmp(lp->l_line, "."))
! 375: break;
! 376:
! 377: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
! 378: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
! 379: lp, l_list);
! 380: dlp = lp;
! 381:
! 382: lp->l_lineno = start;
! 383: lp = ndlp;
! 384: }
! 385: }
! 386:
! 387: /*
! 388: * always resort lines as the markers might be put at the
! 389: * same line as we first started editing.
! 390: */
! 391: lineno = 0;
! 392: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
! 393: sort->l_lineno = lineno++;
! 394: dlines->l_nblines = lineno - 1;
! 395: }
! 396:
! 397: return (0);
! 398: }
! 399:
! 400: /*
! 401: * Pick up the line numbers of all changes from one change file.
! 402: * (This puts the numbers in a vector, which is not strictly necessary,
! 403: * since the vector is processed in one sequential pass.
! 404: * The vector could be optimized out of existence)
! 405: */
! 406: static size_t
! 407: readin(char *name, struct diff **dd)
! 408: {
! 409: int a, b, c, d;
! 410: char kind, *p;
! 411: size_t i;
! 412:
! 413: fp[0] = fopen(name, "r");
! 414: for (i = 0; (p = getchange(fp[0])); i++) {
! 415: if (i >= szchanges - 1)
! 416: increase();
! 417: a = b = number(&p);
! 418: if (*p == ',') {
! 419: p++;
! 420: b = number(&p);
! 421: }
! 422: kind = *p++;
! 423: c = d = number(&p);
! 424: if (*p==',') {
! 425: p++;
! 426: d = number(&p);
! 427: }
! 428: if (kind == 'a')
! 429: a++;
! 430: if (kind == 'd')
! 431: c++;
! 432: b++;
! 433: d++;
! 434: (*dd)[i].old.from = a;
! 435: (*dd)[i].old.to = b;
! 436: (*dd)[i].new.from = c;
! 437: (*dd)[i].new.to = d;
! 438: }
! 439:
! 440: if (i) {
! 441: (*dd)[i].old.from = (*dd)[i-1].old.to;
! 442: (*dd)[i].new.from = (*dd)[i-1].new.to;
! 443: }
! 444: (void)fclose(fp[0]);
! 445:
! 446: return (i);
! 447: }
! 448:
! 449: static int
! 450: number(char **lc)
! 451: {
! 452: int nn;
! 453:
! 454: nn = 0;
! 455: while (isdigit((unsigned char)(**lc)))
! 456: nn = nn*10 + *(*lc)++ - '0';
! 457:
! 458: return (nn);
! 459: }
! 460:
! 461: static char *
! 462: getchange(FILE *b)
! 463: {
! 464: char *line;
! 465:
! 466: while ((line = getline(b, NULL))) {
! 467: if (isdigit((unsigned char)line[0]))
! 468: return (line);
! 469: }
! 470:
! 471: return (NULL);
! 472: }
! 473:
! 474: static char *
! 475: getline(FILE *b, size_t *n)
! 476: {
! 477: char *cp;
! 478: size_t len;
! 479: static char *buf;
! 480: static size_t bufsize;
! 481:
! 482: if ((cp = fgetln(b, &len)) == NULL)
! 483: return (NULL);
! 484:
! 485: if (cp[len - 1] != '\n')
! 486: len++;
! 487: if (len + 1 > bufsize) {
! 488: char *newbuf;
! 489: do {
! 490: bufsize += 1024;
! 491: } while (len + 1 > bufsize);
! 492: newbuf = xrealloc(buf, 1, bufsize);
! 493: buf = newbuf;
! 494: }
! 495: memcpy(buf, cp, len - 1);
! 496: buf[len - 1] = '\n';
! 497: buf[len] = '\0';
! 498: if (n != NULL)
! 499: *n = len;
! 500:
! 501: return (buf);
! 502: }
! 503:
! 504: static int
! 505: merge(size_t m1, size_t m2)
! 506: {
! 507: struct diff *d1, *d2, *d3;
! 508: int dpl, j, t1, t2;
! 509:
! 510: d1 = d13;
! 511: d2 = d23;
! 512: j = 0;
! 513: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
! 514: if (debug) {
! 515: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
! 516: d1->old.from, d1->old.to,
! 517: d1->new.from, d1->new.to,
! 518: d2->old.from, d2->old.to,
! 519: d2->new.from, d2->new.to);
! 520: }
! 521:
! 522: /* first file is different from others */
! 523: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
! 524: /* stuff peculiar to 1st file */
! 525: if (eflag==0) {
! 526: separate("1");
! 527: change(1, &d1->old, 0);
! 528: keep(2, &d1->new);
! 529: change(3, &d1->new, 0);
! 530: }
! 531: d1++;
! 532: continue;
! 533: }
! 534:
! 535: /* second file is different from others */
! 536: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
! 537: if (eflag==0) {
! 538: separate("2");
! 539: keep(1, &d2->new);
! 540: change(2, &d2->old, 0);
! 541: change(3, &d2->new, 0);
! 542: }
! 543: d2++;
! 544: continue;
! 545: }
! 546:
! 547: /*
! 548: * Merge overlapping changes in first file
! 549: * this happens after extension (see below).
! 550: */
! 551: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
! 552: d1[1].old.from = d1->old.from;
! 553: d1[1].new.from = d1->new.from;
! 554: d1++;
! 555: continue;
! 556: }
! 557:
! 558: /* merge overlapping changes in second */
! 559: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
! 560: d2[1].old.from = d2->old.from;
! 561: d2[1].new.from = d2->new.from;
! 562: d2++;
! 563: continue;
! 564: }
! 565: /* stuff peculiar to third file or different in all */
! 566: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
! 567: dpl = duplicate(&d1->old,&d2->old);
! 568: if (dpl == -1)
! 569: return (-1);
! 570:
! 571: /*
! 572: * dpl = 0 means all files differ
! 573: * dpl = 1 means files 1 and 2 identical
! 574: */
! 575: if (eflag==0) {
! 576: separate(dpl ? "3" : "");
! 577: change(1, &d1->old, dpl);
! 578: change(2, &d2->old, 0);
! 579: d3 = d1->old.to > d1->old.from ? d1 : d2;
! 580: change(3, &d3->new, 0);
! 581: } else
! 582: j = edit(d1, dpl, j);
! 583: d1++;
! 584: d2++;
! 585: continue;
! 586: }
! 587:
! 588: /*
! 589: * Overlapping changes from file 1 and 2; extend changes
! 590: * appropriately to make them coincide.
! 591: */
! 592: if (d1->new.from < d2->new.from) {
! 593: d2->old.from -= d2->new.from-d1->new.from;
! 594: d2->new.from = d1->new.from;
! 595: } else if (d2->new.from < d1->new.from) {
! 596: d1->old.from -= d1->new.from-d2->new.from;
! 597: d1->new.from = d2->new.from;
! 598: }
! 599: if (d1->new.to > d2->new.to) {
! 600: d2->old.to += d1->new.to - d2->new.to;
! 601: d2->new.to = d1->new.to;
! 602: } else if (d2->new.to > d1->new.to) {
! 603: d1->old.to += d2->new.to - d1->new.to;
! 604: d1->new.to = d2->new.to;
! 605: }
! 606: }
! 607:
! 608: return (edscript(j));
! 609: }
! 610:
! 611: static void
! 612: separate(const char *s)
! 613: {
! 614: diff_output("====%s\n", s);
! 615: }
! 616:
! 617: /*
! 618: * The range of lines rold.from thru rold.to in file i is to be changed.
! 619: * It is to be printed only if it does not duplicate something to be
! 620: * printed later.
! 621: */
! 622: static void
! 623: change(int i, struct range *rold, int fdup)
! 624: {
! 625: diff_output("%d:", i);
! 626: last[i] = rold->to;
! 627: prange(rold);
! 628: if (fdup || debug)
! 629: return;
! 630: i--;
! 631: (void)skip(i, rold->from, NULL);
! 632: (void)skip(i, rold->to, " ");
! 633: }
! 634:
! 635: /*
! 636: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
! 637: */
! 638: static void
! 639: prange(struct range *rold)
! 640: {
! 641: if (rold->to <= rold->from)
! 642: diff_output("%da\n", rold->from - 1);
! 643: else {
! 644: diff_output("%d", rold->from);
! 645: if (rold->to > rold->from+1)
! 646: diff_output(",%d", rold->to - 1);
! 647: diff_output("c\n");
! 648: }
! 649: }
! 650:
! 651: /*
! 652: * No difference was reported by diff between file 1 (or 2) and file 3,
! 653: * and an artificial dummy difference (trange) must be ginned up to
! 654: * correspond to the change reported in the other file.
! 655: */
! 656: static void
! 657: keep(int i, struct range *rnew)
! 658: {
! 659: int delta;
! 660: struct range trange;
! 661:
! 662: delta = last[3] - last[i];
! 663: trange.from = rnew->from - delta;
! 664: trange.to = rnew->to - delta;
! 665: change(i, &trange, 1);
! 666: }
! 667:
! 668: /*
! 669: * skip to just before line number from in file "i". If "pr" is non-NULL,
! 670: * print all skipped stuff with string pr as a prefix.
! 671: */
! 672: static int
! 673: skip(int i, int from, char *pr)
! 674: {
! 675: size_t j, n;
! 676: char *line;
! 677:
! 678: for (n = 0; cline[i] < from - 1; n += j) {
! 679: if ((line = getline(fp[i], &j)) == NULL)
! 680: return (-1);
! 681: if (pr != NULL)
! 682: diff_output("%s%s", pr, line);
! 683: cline[i]++;
! 684: }
! 685: return ((int) n);
! 686: }
! 687:
! 688: /*
! 689: * Return 1 or 0 according as the old range (in file 1) contains exactly
! 690: * the same data as the new range (in file 2).
! 691: */
! 692: static int
! 693: duplicate(struct range *r1, struct range *r2)
! 694: {
! 695: int c,d;
! 696: int nchar;
! 697: int nline;
! 698:
! 699: if (r1->to-r1->from != r2->to-r2->from)
! 700: return (0);
! 701: (void)skip(0, r1->from, NULL);
! 702: (void)skip(1, r2->from, NULL);
! 703: nchar = 0;
! 704: for (nline=0; nline < r1->to - r1->from; nline++) {
! 705: do {
! 706: c = getc(fp[0]);
! 707: d = getc(fp[1]);
! 708: if (c == -1 || d== -1)
! 709: return (-1);
! 710: nchar++;
! 711: if (c != d) {
! 712: repos(nchar);
! 713: return (0);
! 714: }
! 715: } while (c != '\n');
! 716: }
! 717: repos(nchar);
! 718: return (1);
! 719: }
! 720:
! 721: static void
! 722: repos(int nchar)
! 723: {
! 724: int i;
! 725:
! 726: for (i = 0; i < 2; i++)
! 727: (void)fseek(fp[i], (long)-nchar, 1);
! 728: }
! 729:
! 730: /*
! 731: * collect an editing script for later regurgitation
! 732: */
! 733: static int
! 734: edit(struct diff *diff, int fdup, int j)
! 735: {
! 736: if (((fdup + 1) & eflag) == 0)
! 737: return (j);
! 738: j++;
! 739: overlap[j] = !fdup;
! 740: if (!fdup)
! 741: overlapcnt++;
! 742: de[j].old.from = diff->old.from;
! 743: de[j].old.to = diff->old.to;
! 744: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
! 745: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
! 746: return (j);
! 747: }
! 748:
! 749: /* regurgitate */
! 750: static int
! 751: edscript(int n)
! 752: {
! 753: int j, k;
! 754: char block[BUFSIZ+1];
! 755:
! 756: for (n = n; n > 0; n--) {
! 757: if (!oflag || !overlap[n])
! 758: prange(&de[n].old);
! 759: else
! 760: diff_output("%da\n=======\n", de[n].old.to -1);
! 761: (void)fseek(fp[2], (long)de[n].new.from, 0);
! 762: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
! 763: j = k > BUFSIZ ? BUFSIZ : k;
! 764: if (fread(block, (size_t)1, (size_t)j,
! 765: fp[2]) != (size_t)j)
! 766: return (-1);
! 767: block[j] = '\0';
! 768: diff_output("%s", block);
! 769: }
! 770:
! 771: if (!oflag || !overlap[n])
! 772: diff_output(".\n");
! 773: else {
! 774: diff_output("%s\n.\n", f3mark);
! 775: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
! 776: }
! 777: }
! 778:
! 779: return (overlapcnt);
! 780: }
! 781:
! 782: static void
! 783: increase(void)
! 784: {
! 785: struct diff *p;
! 786: char *q;
! 787: size_t newsz, incr;
! 788:
! 789: /* are the memset(3) calls needed? */
! 790: newsz = szchanges == 0 ? 64 : 2 * szchanges;
! 791: incr = newsz - szchanges;
! 792:
! 793: p = xrealloc(d13, newsz, sizeof(*d13));
! 794: memset(p + szchanges, 0, incr * sizeof(*d13));
! 795: d13 = p;
! 796: p = xrealloc(d23, newsz, sizeof(*d23));
! 797: memset(p + szchanges, 0, incr * sizeof(*d23));
! 798: d23 = p;
! 799: p = xrealloc(de, newsz, sizeof(*de));
! 800: memset(p + szchanges, 0, incr * sizeof(*de));
! 801: de = p;
! 802: q = xrealloc(overlap, newsz, sizeof(*overlap));
! 803: memset(q + szchanges, 0, incr * sizeof(*overlap));
! 804: overlap = q;
! 805: szchanges = newsz;
! 806: }
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