Annotation of src/usr.bin/cvs/diff3.c, Revision 1.1
1.1 ! joris 1: /* $OpenBSD: diff3prog.c,v 1.7 2005/08/01 08:17:57 otto 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[] = "$OpenBSD: diff3prog.c,v 1.7 2005/08/01 08:17:57 otto Exp $";
! 75: #endif /* not lint */
! 76:
! 77: #include <sys/queue.h>
! 78:
! 79: #include <err.h>
! 80: #include <ctype.h>
! 81: #include <stdio.h>
! 82: #include <stdlib.h>
! 83: #include <string.h>
! 84: #include <unistd.h>
! 85:
! 86: #include "cvs.h"
! 87: #include "log.h"
! 88: #include "diff.h"
! 89:
! 90: /* diff3 - 3-way differential file comparison */
! 91:
! 92: /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
! 93: *
! 94: * d13 = diff report on f1 vs f3
! 95: * d23 = diff report on f2 vs f3
! 96: * f1, f2, f3 the 3 files
! 97: * if changes in f1 overlap with changes in f3, m1 and m3 are used
! 98: * to mark the overlaps; otherwise, the file names f1 and f3 are used
! 99: * (only for options E and X).
! 100: */
! 101:
! 102: /*
! 103: * "from" is first in range of changed lines; "to" is last+1
! 104: * from=to=line after point of insertion for added lines.
! 105: */
! 106: struct range {
! 107: int from;
! 108: int to;
! 109: };
! 110:
! 111: struct diff {
! 112: struct range old;
! 113: struct range new;
! 114: };
! 115:
! 116: static size_t szchanges;
! 117:
! 118: static struct diff *d13;
! 119: static struct diff *d23;
! 120:
! 121: /*
! 122: * "de" is used to gather editing scripts. These are later spewed out in
! 123: * reverse order. Its first element must be all zero, the "new" component
! 124: * of "de" contains line positions or byte positions depending on when you
! 125: * look (!?). Array overlap indicates which sections in "de" correspond to
! 126: * lines that are different in all three files.
! 127: */
! 128: static struct diff *de;
! 129: static char *overlap;
! 130: static int overlapcnt;
! 131: static FILE *fp[3];
! 132: static int cline[3]; /* # of the last-read line in each file (0-2) */
! 133:
! 134: /*
! 135: * the latest known correspondence between line numbers of the 3 files
! 136: * is stored in last[1-3];
! 137: */
! 138: static int last[4];
! 139: static int eflag;
! 140: static int oflag; /* indicates whether to mark overlaps (-E or -X)*/
! 141: static int debug = 0;
! 142: static char f1mark[40], f3mark[40]; /* markers for -E and -X */
! 143:
! 144: static int duplicate(struct range *, struct range *);
! 145: static int edit(struct diff *, int, int);
! 146: static char *getchange(FILE *);
! 147: static char *getline(FILE *, size_t *);
! 148: static int number(char **);
! 149: static int readin(char *, struct diff **);
! 150: static int skip(int, int, char *);
! 151: static int edscript(int);
! 152: static int merge(int, int);
! 153: static void change(int, struct range *, int);
! 154: static void keep(int, struct range *);
! 155: static void prange(struct range *);
! 156: static void repos(int);
! 157: static void separate(const char *);
! 158: static void increase(void);
! 159: static int diff3_internal(int, char **, const char *, const char *);
! 160:
! 161: BUF *
! 162: cvs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2)
! 163: {
! 164: int ret, argc;
! 165: char *data, *patch;
! 166: char *argv[5], r1[16], r2[16];
! 167: char path1[MAXPATHLEN], path2[MAXPATHLEN], path3[MAXPATHLEN];
! 168: char dp13[MAXPATHLEN], dp23[MAXPATHLEN];
! 169: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
! 170:
! 171: ret = -1;
! 172: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
! 173:
! 174: rcsnum_tostr(rev1, r1, sizeof(r1));
! 175: rcsnum_tostr(rev2, r2, sizeof(r2));
! 176:
! 177: cvs_printf("merging changes between '%s' and '%s'", r1, r2);
! 178: cvs_printf(" into '%s'\n", workfile);
! 179:
! 180: if ((b1 = cvs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
! 181: goto out;
! 182:
! 183: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
! 184: goto out;
! 185:
! 186: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
! 187: goto out;
! 188:
! 189: if ((d1 = cvs_buf_alloc(128, BUF_AUTOEXT)) == NULL)
! 190: goto out;
! 191:
! 192: if ((d2 = cvs_buf_alloc(128, BUF_AUTOEXT)) == NULL)
! 193: goto out;
! 194:
! 195: if ((diffb = cvs_buf_alloc(128, BUF_AUTOEXT)) == NULL)
! 196: goto out;
! 197:
! 198: strlcpy(path1, "/tmp/diff1.XXXXXXXXXX", sizeof(path1));
! 199: if (cvs_buf_write_stmp(b1, path1, 0600) == -1)
! 200: goto out;
! 201:
! 202: strlcpy(path2, "/tmp/diff2.XXXXXXXXXX", sizeof(path2));
! 203: if (cvs_buf_write_stmp(b2, path2, 0600) == -1)
! 204: goto out;
! 205:
! 206: strlcpy(path3, "/tmp/diff3.XXXXXXXXXX", sizeof(path3));
! 207: if (cvs_buf_write_stmp(b3, path3, 0600) == -1)
! 208: goto out;
! 209:
! 210: cvs_buf_free(b2);
! 211: b2 = NULL;
! 212:
! 213: cvs_diffreg(path1, path3, d1);
! 214: cvs_diffreg(path2, path3, d2);
! 215:
! 216: strlcpy(dp13, "/tmp/d13.XXXXXXXXXX", sizeof(dp13));
! 217: if (cvs_buf_write_stmp(d1, dp13, 0600) < 0)
! 218: goto out;
! 219:
! 220: cvs_buf_free(d1);
! 221: d1 = NULL;
! 222:
! 223: strlcpy(dp23, "/tmp/d23.XXXXXXXXXX", sizeof(dp23));
! 224: if (cvs_buf_write_stmp(d2, dp23, 0600) < 0)
! 225: goto out;
! 226:
! 227: cvs_buf_free(d2);
! 228: d2 = NULL;
! 229:
! 230: argc = 0;
! 231: diffbuf = diffb;
! 232: argv[argc++] = dp13;
! 233: argv[argc++] = dp23;
! 234: argv[argc++] = path1;
! 235: argv[argc++] = path2;
! 236: argv[argc++] = path3;
! 237: if ((ret = diff3_internal(argc, argv, workfile, r2)) < 0)
! 238: goto out;
! 239:
! 240: if (cvs_buf_putc(diffb, '\0') < 0) {
! 241: cvs_buf_free(diffb);
! 242: goto out;
! 243: }
! 244:
! 245: if (cvs_buf_putc(b1, '\0') < 0) {
! 246: cvs_buf_free(diffb);
! 247: goto out;
! 248: }
! 249:
! 250: patch = cvs_buf_release(diffb);
! 251: data = cvs_buf_release(b1);
! 252: diffb = b1 = NULL;
! 253:
! 254: if ((diffb = cvs_patchfile(data, patch, ed_patch_lines)) == NULL)
! 255: goto out;
! 256:
! 257: free(data);
! 258: free(patch);
! 259:
! 260: out:
! 261: if (b1 != NULL)
! 262: cvs_buf_free(b1);
! 263: if (b2 != NULL)
! 264: cvs_buf_free(b2);
! 265: if (b3 != NULL)
! 266: cvs_buf_free(b3);
! 267: if (d1 != NULL)
! 268: cvs_buf_free(d1);
! 269: if (d2 != NULL)
! 270: cvs_buf_free(d2);
! 271:
! 272: (void)unlink(path1);
! 273: (void)unlink(path2);
! 274: (void)unlink(path3);
! 275: (void)unlink(dp13);
! 276: (void)unlink(dp23);
! 277:
! 278: return (diffb);
! 279: }
! 280:
! 281: static int
! 282: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
! 283: {
! 284: int i, m, n;
! 285:
! 286: /* XXX */
! 287: eflag = 3;
! 288: oflag = 1;
! 289:
! 290: if (argc < 5)
! 291: return (-1);
! 292:
! 293: snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
! 294: snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
! 295:
! 296: increase();
! 297: m = readin(argv[0], &d13);
! 298: n = readin(argv[1], &d23);
! 299:
! 300: for (i = 0; i <= 2; i++) {
! 301: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
! 302: cvs_log(LP_ERRNO, "%s", argv[i + 2]);
! 303: return (-1);
! 304: }
! 305: }
! 306:
! 307: return (merge(m, n));
! 308: }
! 309:
! 310: int
! 311: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
! 312: {
! 313: char op, *ep;
! 314: struct cvs_line *sort, *lp, *dlp, *ndlp;
! 315: int start, end, busy, i, lineno;
! 316:
! 317: dlp = TAILQ_FIRST(&(dlines->l_lines));
! 318: lp = TAILQ_FIRST(&(plines->l_lines));
! 319:
! 320: busy = 0;
! 321: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
! 322: lp = TAILQ_NEXT(lp, l_list)) {
! 323: op = lp->l_line[strlen(lp->l_line) - 1];
! 324: start = (int)strtol(lp->l_line, &ep, 10);
! 325: if (op == 'a') {
! 326: if ((start > dlines->l_nblines) ||
! 327: (start < 0) || (*ep != 'a'))
! 328: return (-1);
! 329: } else if (op == 'c') {
! 330: if ((start > dlines->l_nblines) ||
! 331: (start < 0) || (*ep != ','))
! 332: return (-1);
! 333:
! 334: ep++;
! 335: end = (int)strtol(ep, &ep, 10);
! 336: if ((end < 0) || (*ep != 'c'))
! 337: return (-1);
! 338: }
! 339:
! 340: for (;;) {
! 341: if (dlp == NULL)
! 342: break;
! 343: if (dlp->l_lineno == start)
! 344: break;
! 345: if (dlp->l_lineno > start) {
! 346: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
! 347: } else if (dlp->l_lineno < start) {
! 348: ndlp = TAILQ_NEXT(dlp, l_list);
! 349: if (ndlp->l_lineno > start)
! 350: break;
! 351: dlp = ndlp;
! 352: }
! 353: }
! 354:
! 355: if (dlp == NULL)
! 356: return (-1);
! 357:
! 358: if (op == 'c') {
! 359: for (i = start; i <= end; i++) {
! 360: ndlp = TAILQ_NEXT(dlp, l_list);
! 361: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
! 362: dlp = ndlp;
! 363: }
! 364: }
! 365:
! 366: if (op == 'a' || op == 'c') {
! 367: for (;;) {
! 368: ndlp = lp;
! 369: lp = TAILQ_NEXT(lp, l_list);
! 370: if (lp == NULL)
! 371: return (-1);
! 372:
! 373: if (!strcmp(lp->l_line, "."))
! 374: break;
! 375:
! 376: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
! 377: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
! 378: lp, l_list);
! 379: dlp = lp;
! 380:
! 381: lp->l_lineno = start;
! 382: lp = ndlp;
! 383: }
! 384: }
! 385:
! 386: /*
! 387: * always resort lines as the markers might be put at the
! 388: * same line as we first started editing.
! 389: */
! 390: lineno = 0;
! 391: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
! 392: sort->l_lineno = lineno++;
! 393: dlines->l_nblines = lineno - 1;
! 394: }
! 395:
! 396: return (0);
! 397: }
! 398:
! 399: /*
! 400: * Pick up the line numbers of all changes from one change file.
! 401: * (This puts the numbers in a vector, which is not strictly necessary,
! 402: * since the vector is processed in one sequential pass.
! 403: * The vector could be optimized out of existence)
! 404: */
! 405: static int
! 406: readin(char *name, struct diff **dd)
! 407: {
! 408: int a, b, c, d;
! 409: char kind, *p;
! 410: size_t i;
! 411:
! 412: fp[0] = fopen(name, "r");
! 413: for (i = 0; (p = getchange(fp[0])); i++) {
! 414: if (i >= szchanges - 1)
! 415: increase();
! 416: a = b = number(&p);
! 417: if (*p == ',') {
! 418: p++;
! 419: b = number(&p);
! 420: }
! 421: kind = *p++;
! 422: c = d = number(&p);
! 423: if (*p==',') {
! 424: p++;
! 425: d = number(&p);
! 426: }
! 427: if (kind == 'a')
! 428: a++;
! 429: if (kind == 'd')
! 430: c++;
! 431: b++;
! 432: d++;
! 433: (*dd)[i].old.from = a;
! 434: (*dd)[i].old.to = b;
! 435: (*dd)[i].new.from = c;
! 436: (*dd)[i].new.to = d;
! 437: }
! 438:
! 439: (*dd)[i].old.from = (*dd)[i-1].old.to;
! 440: (*dd)[i].new.from = (*dd)[i-1].new.to;
! 441: (void)fclose(fp[0]);
! 442:
! 443: return (i);
! 444: }
! 445:
! 446: static int
! 447: number(char **lc)
! 448: {
! 449: int nn;
! 450:
! 451: nn = 0;
! 452: while (isdigit((unsigned char)(**lc)))
! 453: nn = nn*10 + *(*lc)++ - '0';
! 454:
! 455: return (nn);
! 456: }
! 457:
! 458: static char *
! 459: getchange(FILE *b)
! 460: {
! 461: char *line;
! 462:
! 463: while ((line = getline(b, NULL))) {
! 464: if (isdigit((unsigned char)line[0]))
! 465: return (line);
! 466: }
! 467:
! 468: return (NULL);
! 469: }
! 470:
! 471: static char *
! 472: getline(FILE *b, size_t *n)
! 473: {
! 474: char *cp;
! 475: size_t len;
! 476: static char *buf;
! 477: static size_t bufsize;
! 478:
! 479: if ((cp = fgetln(b, &len)) == NULL)
! 480: return (NULL);
! 481:
! 482: if (cp[len - 1] != '\n')
! 483: len++;
! 484: if (len + 1 > bufsize) {
! 485: do {
! 486: bufsize += 1024;
! 487: } while (len + 1 > bufsize);
! 488: if ((buf = realloc(buf, bufsize)) == NULL)
! 489: err(EXIT_FAILURE, NULL);
! 490: }
! 491: memcpy(buf, cp, len - 1);
! 492: buf[len - 1] = '\n';
! 493: buf[len] = '\0';
! 494: if (n != NULL)
! 495: *n = len;
! 496:
! 497: return (buf);
! 498: }
! 499:
! 500: static int
! 501: merge(int m1, int m2)
! 502: {
! 503: struct diff *d1, *d2, *d3;
! 504: int dpl, j, t1, t2;
! 505:
! 506: d1 = d13;
! 507: d2 = d23;
! 508: j = 0;
! 509: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
! 510: if (debug) {
! 511: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
! 512: d1->old.from,d1->old.to,
! 513: d1->new.from,d1->new.to,
! 514: d2->old.from,d2->old.to,
! 515: d2->new.from,d2->new.to);
! 516: }
! 517:
! 518: /* first file is different from others */
! 519: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
! 520: /* stuff peculiar to 1st file */
! 521: if (eflag==0) {
! 522: separate("1");
! 523: change(1, &d1->old, 0);
! 524: keep(2, &d1->new);
! 525: change(3, &d1->new, 0);
! 526: }
! 527: d1++;
! 528: continue;
! 529: }
! 530:
! 531: /* second file is different from others */
! 532: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
! 533: if (eflag==0) {
! 534: separate("2");
! 535: keep(1, &d2->new);
! 536: change(2, &d2->old, 0);
! 537: change(3, &d2->new, 0);
! 538: }
! 539: d2++;
! 540: continue;
! 541: }
! 542:
! 543: /*
! 544: * Merge overlapping changes in first file
! 545: * this happens after extension (see below).
! 546: */
! 547: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
! 548: d1[1].old.from = d1->old.from;
! 549: d1[1].new.from = d1->new.from;
! 550: d1++;
! 551: continue;
! 552: }
! 553:
! 554: /* merge overlapping changes in second */
! 555: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
! 556: d2[1].old.from = d2->old.from;
! 557: d2[1].new.from = d2->new.from;
! 558: d2++;
! 559: continue;
! 560: }
! 561: /* stuff peculiar to third file or different in all */
! 562: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
! 563: dpl = duplicate(&d1->old,&d2->old);
! 564: if (dpl == -1)
! 565: return (-1);
! 566:
! 567: /*
! 568: * dpl = 0 means all files differ
! 569: * dpl = 1 means files 1 and 2 identical
! 570: */
! 571: if (eflag==0) {
! 572: separate(dpl ? "3" : "");
! 573: change(1, &d1->old, dpl);
! 574: change(2, &d2->old, 0);
! 575: d3 = d1->old.to > d1->old.from ? d1 : d2;
! 576: change(3, &d3->new, 0);
! 577: } else
! 578: j = edit(d1, dpl, j);
! 579: d1++;
! 580: d2++;
! 581: continue;
! 582: }
! 583:
! 584: /*
! 585: * Overlapping changes from file 1 and 2; extend changes
! 586: * appropriately to make them coincide.
! 587: */
! 588: if (d1->new.from < d2->new.from) {
! 589: d2->old.from -= d2->new.from-d1->new.from;
! 590: d2->new.from = d1->new.from;
! 591: } else if (d2->new.from < d1->new.from) {
! 592: d1->old.from -= d1->new.from-d2->new.from;
! 593: d1->new.from = d2->new.from;
! 594: }
! 595: if (d1->new.to > d2->new.to) {
! 596: d2->old.to += d1->new.to - d2->new.to;
! 597: d2->new.to = d1->new.to;
! 598: } else if (d2->new.to > d1->new.to) {
! 599: d1->old.to += d2->new.to - d1->new.to;
! 600: d1->new.to = d2->new.to;
! 601: }
! 602: }
! 603:
! 604: return (edscript(j));
! 605: }
! 606:
! 607: static void
! 608: separate(const char *s)
! 609: {
! 610: diff_output("====%s\n", s);
! 611: }
! 612:
! 613: /*
! 614: * The range of lines rold.from thru rold.to in file i is to be changed.
! 615: * It is to be printed only if it does not duplicate something to be
! 616: * printed later.
! 617: */
! 618: static void
! 619: change(int i, struct range *rold, int fdup)
! 620: {
! 621: diff_output("%d:", i);
! 622: last[i] = rold->to;
! 623: prange(rold);
! 624: if (fdup || debug)
! 625: return;
! 626: i--;
! 627: (void)skip(i, rold->from, NULL);
! 628: (void)skip(i, rold->to, " ");
! 629: }
! 630:
! 631: /*
! 632: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
! 633: */
! 634: static void
! 635: prange(struct range *rold)
! 636: {
! 637: if (rold->to <= rold->from)
! 638: diff_output("%da\n", rold->from - 1);
! 639: else {
! 640: diff_output("%d", rold->from);
! 641: if (rold->to > rold->from+1)
! 642: diff_output(",%d", rold->to - 1);
! 643: diff_output("c\n");
! 644: }
! 645: }
! 646:
! 647: /*
! 648: * No difference was reported by diff between file 1 (or 2) and file 3,
! 649: * and an artificial dummy difference (trange) must be ginned up to
! 650: * correspond to the change reported in the other file.
! 651: */
! 652: static void
! 653: keep(int i, struct range *rnew)
! 654: {
! 655: int delta;
! 656: struct range trange;
! 657:
! 658: delta = last[3] - last[i];
! 659: trange.from = rnew->from - delta;
! 660: trange.to = rnew->to - delta;
! 661: change(i, &trange, 1);
! 662: }
! 663:
! 664: /*
! 665: * skip to just before line number from in file "i". If "pr" is non-NULL,
! 666: * print all skipped stuff with string pr as a prefix.
! 667: */
! 668: static int
! 669: skip(int i, int from, char *pr)
! 670: {
! 671: size_t j, n;
! 672: char *line;
! 673:
! 674: for (n = 0; cline[i] < from - 1; n += j) {
! 675: if ((line = getline(fp[i], &j)) == NULL)
! 676: return (-1);
! 677: if (pr != NULL)
! 678: diff_output("%s%s", pr, line);
! 679: cline[i]++;
! 680: }
! 681: return ((int) n);
! 682: }
! 683:
! 684: /*
! 685: * Return 1 or 0 according as the old range (in file 1) contains exactly
! 686: * the same data as the new range (in file 2).
! 687: */
! 688: static int
! 689: duplicate(struct range *r1, struct range *r2)
! 690: {
! 691: int c,d;
! 692: int nchar;
! 693: int nline;
! 694:
! 695: if (r1->to-r1->from != r2->to-r2->from)
! 696: return (0);
! 697: (void)skip(0, r1->from, NULL);
! 698: (void)skip(1, r2->from, NULL);
! 699: nchar = 0;
! 700: for (nline=0; nline < r1->to - r1->from; nline++) {
! 701: do {
! 702: c = getc(fp[0]);
! 703: d = getc(fp[1]);
! 704: if (c == -1 || d== -1)
! 705: return (-1);
! 706: nchar++;
! 707: if (c != d) {
! 708: repos(nchar);
! 709: return (0);
! 710: }
! 711: } while (c != '\n');
! 712: }
! 713: repos(nchar);
! 714: return (1);
! 715: }
! 716:
! 717: static void
! 718: repos(int nchar)
! 719: {
! 720: int i;
! 721:
! 722: for (i = 0; i < 2; i++)
! 723: (void)fseek(fp[i], (long)-nchar, 1);
! 724: }
! 725:
! 726: /*
! 727: * collect an editing script for later regurgitation
! 728: */
! 729: static int
! 730: edit(struct diff *diff, int fdup, int j)
! 731: {
! 732: if (((fdup + 1) & eflag) == 0)
! 733: return (j);
! 734: j++;
! 735: overlap[j] = !fdup;
! 736: if (!fdup)
! 737: overlapcnt++;
! 738: de[j].old.from = diff->old.from;
! 739: de[j].old.to = diff->old.to;
! 740: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
! 741: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
! 742: return (j);
! 743: }
! 744:
! 745: /* regurgitate */
! 746: static int
! 747: edscript(int n)
! 748: {
! 749: int j, k;
! 750: char block[BUFSIZ];
! 751:
! 752: for (n = n; n > 0; n--) {
! 753: if (!oflag || !overlap[n])
! 754: prange(&de[n].old);
! 755: else
! 756: diff_output("%da\n=======\n", de[n].old.to -1);
! 757: (void)fseek(fp[2], (long)de[n].new.from, 0);
! 758: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
! 759: j = k > BUFSIZ ? BUFSIZ : k;
! 760: if (fread(block, 1, j, fp[2]) != (size_t)j)
! 761: return (-1);
! 762: block[j] = '\0';
! 763: diff_output("%s", block);
! 764: }
! 765: if (!oflag || !overlap[n])
! 766: diff_output(".\n");
! 767: else {
! 768: diff_output("%s\n.\n", f3mark);
! 769: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
! 770: }
! 771: }
! 772:
! 773: return (overlapcnt);
! 774: }
! 775:
! 776: static void
! 777: increase(void)
! 778: {
! 779: struct diff *p;
! 780: char *q;
! 781: size_t newsz, incr;
! 782:
! 783: /* are the memset(3) calls needed? */
! 784: newsz = szchanges == 0 ? 64 : 2 * szchanges;
! 785: incr = newsz - szchanges;
! 786:
! 787: p = realloc(d13, newsz * sizeof(struct diff));
! 788: if (p == NULL)
! 789: err(1, NULL);
! 790: memset(p + szchanges, 0, incr * sizeof(struct diff));
! 791: d13 = p;
! 792: p = realloc(d23, newsz * sizeof(struct diff));
! 793: if (p == NULL)
! 794: err(1, NULL);
! 795: memset(p + szchanges, 0, incr * sizeof(struct diff));
! 796: d23 = p;
! 797: p = realloc(de, newsz * sizeof(struct diff));
! 798: if (p == NULL)
! 799: err(1, NULL);
! 800: memset(p + szchanges, 0, incr * sizeof(struct diff));
! 801: de = p;
! 802: q = realloc(overlap, newsz * sizeof(char));
! 803: if (q == NULL)
! 804: err(1, NULL);
! 805: memset(q + szchanges, 0, incr * sizeof(char));
! 806: overlap = q;
! 807: szchanges = newsz;
! 808: }
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