Annotation of src/usr.bin/cvs/diff3.c, Revision 1.42
1.42 ! joris 1: /* $OpenBSD: diff3.c,v 1.41 2008/02/23 23:42:23 joris Exp $ */
1.1 joris 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
1.11 reyk 74: static const char rcsid[] =
1.42 ! joris 75: "$OpenBSD: diff3.c,v 1.41 2008/02/23 23:42:23 joris Exp $";
1.1 joris 76: #endif /* not lint */
77:
1.35 otto 78: #include <ctype.h>
79: #include <errno.h>
80: #include <fcntl.h>
1.38 tobias 81: #include <stdio.h>
1.35 otto 82: #include <stdlib.h>
83: #include <string.h>
84: #include <unistd.h>
1.1 joris 85:
1.39 tobias 86: #include "atomicio.h"
1.1 joris 87: #include "cvs.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;
1.2 joris 130: static int overlapcnt = 0;
1.1 joris 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;
1.33 joris 142: static char f1mark[MAXPATHLEN], f3mark[MAXPATHLEN]; /* markers for -E and -X */
1.1 joris 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 **);
1.42 ! joris 149: static size_t readin(int, struct diff **);
1.1 joris 150: static int skip(int, int, char *);
151: static int edscript(int);
1.20 ray 152: static int merge(size_t, size_t);
1.1 joris 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:
1.5 xsa 161: int diff3_conflicts = 0;
1.4 joris 162:
1.42 ! joris 163: static int fds[5];
! 164:
1.33 joris 165: void
166: cvs_merge_file(struct cvs_file *cf, int verbose)
1.1 joris 167: {
1.42 ! joris 168: int i, argc;
1.1 joris 169: char *data, *patch;
1.37 xsa 170: char *argv[5], r1[CVS_REV_BUFSZ], r2[CVS_REV_BUFSZ];
1.28 xsa 171: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 172: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
1.30 niallo 173: size_t dlen, plen;
1.33 joris 174: struct cvs_line *lp;
175: struct cvs_lines *dlines, *plines;
1.1 joris 176:
1.41 joris 177: overlapcnt = 0;
1.1 joris 178: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.33 joris 179: rcsnum_tostr(cf->file_ent->ce_rev, r1, sizeof(r1));
180: rcsnum_tostr(cf->file_rcsrev, r2, sizeof(r2));
1.1 joris 181:
1.40 tobias 182: b1 = cvs_buf_load_fd(cf->fd);
183: d1 = cvs_buf_alloc(128);
184: d2 = cvs_buf_alloc(128);
185: diffb = cvs_buf_alloc(128);
1.1 joris 186:
1.28 xsa 187: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
188: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
189: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
190:
1.42 ! joris 191: fds[2] = cvs_buf_write_stmp(b1, path1, NULL);
1.32 niallo 192: if (verbose == 1)
193: cvs_printf("Retrieving revision %s\n", r1);
1.42 ! joris 194: fds[3] = rcs_rev_write_stmp(cf->file_rcs, cf->file_ent->ce_rev,
! 195: path2, 0);
1.32 niallo 196: if (verbose == 1)
197: cvs_printf("Retrieving revision %s\n", r2);
1.42 ! joris 198: fds[4] = rcs_rev_write_stmp(cf->file_rcs, cf->file_rcsrev, path3, 0);
1.1 joris 199:
1.42 ! joris 200: cvs_diffreg(path1, path3, fds[2], fds[4], d1);
! 201: cvs_diffreg(path2, path3, fds[3], fds[4], d2);
1.1 joris 202:
1.28 xsa 203: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.42 ! joris 204: fds[0] = cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 205: cvs_buf_free(d1);
206:
1.28 xsa 207: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.42 ! joris 208: fds[1] = cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 209: cvs_buf_free(d2);
210:
211: argc = 0;
212: diffbuf = diffb;
213: argv[argc++] = dp13;
214: argv[argc++] = dp23;
215: argv[argc++] = path1;
216: argv[argc++] = path2;
217: argv[argc++] = path3;
1.7 joris 218:
1.42 ! joris 219: if (lseek(fds[2], SEEK_SET, 0) < 0)
! 220: fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno));
! 221: if (lseek(fds[3], SEEK_SET, 0) < 0)
! 222: fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno));
! 223: if (lseek(fds[4], SEEK_SET, 0) < 0)
! 224: fatal("cvs_merge_file: lseek fds[4]: %s", strerror(errno));
! 225:
1.33 joris 226: diff3_conflicts = diff3_internal(argc, argv, cf->file_path, r2);
227: if (diff3_conflicts < 0)
228: fatal("cvs_merge_file: merging failed for an unknown reason");
1.1 joris 229:
1.30 niallo 230: plen = cvs_buf_len(diffb);
1.1 joris 231: patch = cvs_buf_release(diffb);
1.30 niallo 232: dlen = cvs_buf_len(b1);
1.1 joris 233: data = cvs_buf_release(b1);
234:
1.33 joris 235: cvs_printf("Merging differences between %s and %s into `%s'\n",
236: r1, r2, cf->file_path);
237:
238: dlines = cvs_splitlines(data, dlen);
239: plines = cvs_splitlines(patch, plen);
240: ed_patch_lines(dlines, plines);
241: cvs_freelines(plines);
1.7 joris 242:
1.23 deraadt 243: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 244: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 245: "please correct.", diff3_conflicts,
1.11 reyk 246: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 247: }
1.1 joris 248:
1.42 ! joris 249: (void)close(cf->fd);
! 250: cf->fd = open(cf->file_path, O_WRONLY | O_TRUNC);
! 251: if (cf->fd == -1) {
! 252: fatal("cvs_merge_file: failed to reopen fd for writing: %s",
! 253: strerror(errno));
! 254: }
! 255:
1.33 joris 256: TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) {
257: if (lp->l_line == NULL)
258: continue;
259:
1.39 tobias 260: if (atomicio(vwrite, cf->fd, lp->l_line, lp->l_len) !=
261: lp->l_len)
1.33 joris 262: fatal("cvs_merge_file: %s", strerror(errno));
263: }
264:
265: cvs_freelines(dlines);
266:
267: if (data != NULL)
268: xfree(data);
1.8 joris 269: xfree(patch);
1.1 joris 270:
1.42 ! joris 271: for (i = 0; i < 3; i++)
! 272: fclose(fp[i]);
! 273:
1.1 joris 274: (void)unlink(path1);
275: (void)unlink(path2);
276: (void)unlink(path3);
277: (void)unlink(dp13);
278: (void)unlink(dp23);
1.28 xsa 279:
1.33 joris 280: xfree(path1);
281: xfree(path2);
282: xfree(path3);
283: xfree(dp13);
284: xfree(dp23);
1.1 joris 285: }
286:
287: static int
288: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
289: {
1.20 ray 290: size_t m, n;
291: int i;
1.1 joris 292:
293: /* XXX */
294: eflag = 3;
295: oflag = 1;
296:
297: if (argc < 5)
298: return (-1);
299:
1.34 xsa 300: (void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
301: (void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
1.1 joris 302:
303: increase();
1.42 ! joris 304:
! 305: /* fds[0] and fds[1] are closed in readin() */
! 306: cvs_printf("calling readin with fds[0] (%s)\n", argv[0]);
! 307: m = readin(fds[0], &d13);
! 308: cvs_printf("calling readin with fds[1] (%s)\n", argv[1]);
! 309: n = readin(fds[1], &d23);
1.1 joris 310:
311: for (i = 0; i <= 2; i++) {
1.42 ! joris 312: cvs_printf("opening fds[%d] (%s)\n", i + 2, argv[i + 2]);
! 313: if ((fp[i] = fdopen(fds[i + 2], "r")) == NULL) {
1.24 joris 314: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 315: return (-1);
316: }
317: }
318:
319: return (merge(m, n));
320: }
321:
322: int
323: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
324: {
325: char op, *ep;
1.29 xsa 326: struct cvs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.19 xsa 327: int start, end, i, lineno;
1.30 niallo 328: u_char tmp;
1.1 joris 329:
330: dlp = TAILQ_FIRST(&(dlines->l_lines));
331: lp = TAILQ_FIRST(&(plines->l_lines));
332:
1.19 xsa 333: end = 0;
1.1 joris 334: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
335: lp = TAILQ_NEXT(lp, l_list)) {
1.30 niallo 336: /* Skip blank lines */
337: if (lp->l_len < 2)
338: continue;
339: /* NUL-terminate line buffer for strtol() safety. */
340: tmp = lp->l_line[lp->l_len - 1];
341: lp->l_line[lp->l_len - 1] = '\0';
342: /* len - 1 is NUL terminator so we use len - 2 for 'op' */
1.1 joris 343: op = lp->l_line[strlen(lp->l_line) - 1];
344: start = (int)strtol(lp->l_line, &ep, 10);
1.30 niallo 345: /* Restore the last byte of the buffer */
346: lp->l_line[lp->l_len - 1] = tmp;
1.1 joris 347: if (op == 'a') {
1.23 deraadt 348: if (start > dlines->l_nblines ||
349: start < 0 || *ep != 'a')
1.15 niallo 350: fatal("ed_patch_lines");
1.1 joris 351: } else if (op == 'c') {
1.23 deraadt 352: if (start > dlines->l_nblines ||
353: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 354: fatal("ed_patch_lines");
1.1 joris 355:
1.2 joris 356: if (*ep == ',') {
357: ep++;
358: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 359: if (end < 0 || *ep != 'c')
1.15 niallo 360: fatal("ed_patch_lines");
1.2 joris 361: } else {
362: end = start;
363: }
1.1 joris 364: }
365:
1.2 joris 366:
1.1 joris 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, cvs_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)
1.15 niallo 383: fatal("ed_patch_lines");
1.1 joris 384:
1.2 joris 385:
1.1 joris 386: if (op == 'c') {
1.29 xsa 387: insert_after = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.2 joris 388: for (i = 0; i <= (end - start); i++) {
1.1 joris 389: ndlp = TAILQ_NEXT(dlp, l_list);
390: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
391: dlp = ndlp;
392: }
1.29 xsa 393: dlp = insert_after;
1.1 joris 394: }
395:
396: if (op == 'a' || op == 'c') {
397: for (;;) {
398: ndlp = lp;
399: lp = TAILQ_NEXT(lp, l_list);
400: if (lp == NULL)
1.15 niallo 401: fatal("ed_patch_lines");
1.1 joris 402:
1.30 niallo 403: if (!memcmp(lp->l_line, ".", 1))
1.1 joris 404: break;
405:
406: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
407: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
408: lp, l_list);
409: dlp = lp;
410:
411: lp->l_lineno = start;
412: lp = ndlp;
413: }
414: }
415:
416: /*
417: * always resort lines as the markers might be put at the
418: * same line as we first started editing.
419: */
420: lineno = 0;
421: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
422: sort->l_lineno = lineno++;
423: dlines->l_nblines = lineno - 1;
424: }
425:
426: return (0);
427: }
428:
429: /*
430: * Pick up the line numbers of all changes from one change file.
431: * (This puts the numbers in a vector, which is not strictly necessary,
432: * since the vector is processed in one sequential pass.
433: * The vector could be optimized out of existence)
434: */
1.20 ray 435: static size_t
1.42 ! joris 436: readin(int fd, struct diff **dd)
1.1 joris 437: {
438: int a, b, c, d;
439: char kind, *p;
440: size_t i;
441:
1.42 ! joris 442: fp[0] = fdopen(fd, "r");
! 443: if (fp[0] == NULL)
! 444: fatal("readin: fdopen: %s", strerror(errno));
! 445:
1.1 joris 446: for (i = 0; (p = getchange(fp[0])); i++) {
447: if (i >= szchanges - 1)
448: increase();
449: a = b = number(&p);
450: if (*p == ',') {
451: p++;
452: b = number(&p);
453: }
454: kind = *p++;
455: c = d = number(&p);
456: if (*p==',') {
457: p++;
458: d = number(&p);
459: }
460: if (kind == 'a')
461: a++;
462: if (kind == 'd')
463: c++;
464: b++;
465: d++;
466: (*dd)[i].old.from = a;
467: (*dd)[i].old.to = b;
468: (*dd)[i].new.from = c;
469: (*dd)[i].new.to = d;
470: }
471:
1.14 xsa 472: if (i) {
473: (*dd)[i].old.from = (*dd)[i-1].old.to;
474: (*dd)[i].new.from = (*dd)[i-1].new.to;
475: }
1.42 ! joris 476:
1.1 joris 477: (void)fclose(fp[0]);
478:
479: return (i);
480: }
481:
482: static int
483: number(char **lc)
484: {
485: int nn;
486:
487: nn = 0;
488: while (isdigit((unsigned char)(**lc)))
489: nn = nn*10 + *(*lc)++ - '0';
490:
491: return (nn);
492: }
493:
494: static char *
495: getchange(FILE *b)
496: {
497: char *line;
498:
499: while ((line = getline(b, NULL))) {
500: if (isdigit((unsigned char)line[0]))
501: return (line);
502: }
503:
504: return (NULL);
505: }
506:
507: static char *
508: getline(FILE *b, size_t *n)
509: {
510: char *cp;
511: size_t len;
512: static char *buf;
513: static size_t bufsize;
514:
515: if ((cp = fgetln(b, &len)) == NULL)
516: return (NULL);
517:
518: if (cp[len - 1] != '\n')
519: len++;
520: if (len + 1 > bufsize) {
521: do {
522: bufsize += 1024;
523: } while (len + 1 > bufsize);
1.36 ray 524: buf = xrealloc(buf, 1, bufsize);
1.1 joris 525: }
526: memcpy(buf, cp, len - 1);
527: buf[len - 1] = '\n';
528: buf[len] = '\0';
529: if (n != NULL)
530: *n = len;
531:
532: return (buf);
533: }
534:
535: static int
1.20 ray 536: merge(size_t m1, size_t m2)
1.1 joris 537: {
538: struct diff *d1, *d2, *d3;
539: int dpl, j, t1, t2;
540:
541: d1 = d13;
542: d2 = d23;
543: j = 0;
544: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
545: if (debug) {
546: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 547: d1->old.from, d1->old.to,
548: d1->new.from, d1->new.to,
549: d2->old.from, d2->old.to,
550: d2->new.from, d2->new.to);
1.1 joris 551: }
552:
553: /* first file is different from others */
554: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
555: /* stuff peculiar to 1st file */
556: if (eflag==0) {
557: separate("1");
558: change(1, &d1->old, 0);
559: keep(2, &d1->new);
560: change(3, &d1->new, 0);
561: }
562: d1++;
563: continue;
564: }
565:
566: /* second file is different from others */
567: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
568: if (eflag==0) {
569: separate("2");
570: keep(1, &d2->new);
571: change(2, &d2->old, 0);
572: change(3, &d2->new, 0);
573: }
574: d2++;
575: continue;
576: }
577:
578: /*
579: * Merge overlapping changes in first file
580: * this happens after extension (see below).
581: */
582: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
583: d1[1].old.from = d1->old.from;
584: d1[1].new.from = d1->new.from;
585: d1++;
586: continue;
587: }
588:
589: /* merge overlapping changes in second */
590: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
591: d2[1].old.from = d2->old.from;
592: d2[1].new.from = d2->new.from;
593: d2++;
594: continue;
595: }
596: /* stuff peculiar to third file or different in all */
597: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
598: dpl = duplicate(&d1->old,&d2->old);
599: if (dpl == -1)
600: return (-1);
601:
602: /*
603: * dpl = 0 means all files differ
604: * dpl = 1 means files 1 and 2 identical
605: */
606: if (eflag==0) {
607: separate(dpl ? "3" : "");
608: change(1, &d1->old, dpl);
609: change(2, &d2->old, 0);
610: d3 = d1->old.to > d1->old.from ? d1 : d2;
611: change(3, &d3->new, 0);
612: } else
613: j = edit(d1, dpl, j);
614: d1++;
615: d2++;
616: continue;
617: }
618:
619: /*
620: * Overlapping changes from file 1 and 2; extend changes
621: * appropriately to make them coincide.
622: */
623: if (d1->new.from < d2->new.from) {
624: d2->old.from -= d2->new.from-d1->new.from;
625: d2->new.from = d1->new.from;
626: } else if (d2->new.from < d1->new.from) {
627: d1->old.from -= d1->new.from-d2->new.from;
628: d1->new.from = d2->new.from;
629: }
630: if (d1->new.to > d2->new.to) {
631: d2->old.to += d1->new.to - d2->new.to;
632: d2->new.to = d1->new.to;
633: } else if (d2->new.to > d1->new.to) {
634: d1->old.to += d2->new.to - d1->new.to;
635: d1->new.to = d2->new.to;
636: }
637: }
638:
639: return (edscript(j));
640: }
641:
642: static void
643: separate(const char *s)
644: {
645: diff_output("====%s\n", s);
646: }
647:
648: /*
649: * The range of lines rold.from thru rold.to in file i is to be changed.
650: * It is to be printed only if it does not duplicate something to be
651: * printed later.
652: */
653: static void
654: change(int i, struct range *rold, int fdup)
655: {
656: diff_output("%d:", i);
657: last[i] = rold->to;
658: prange(rold);
659: if (fdup || debug)
660: return;
661: i--;
662: (void)skip(i, rold->from, NULL);
663: (void)skip(i, rold->to, " ");
664: }
665:
666: /*
667: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
668: */
669: static void
670: prange(struct range *rold)
671: {
672: if (rold->to <= rold->from)
673: diff_output("%da\n", rold->from - 1);
674: else {
675: diff_output("%d", rold->from);
676: if (rold->to > rold->from+1)
677: diff_output(",%d", rold->to - 1);
678: diff_output("c\n");
679: }
680: }
681:
682: /*
683: * No difference was reported by diff between file 1 (or 2) and file 3,
684: * and an artificial dummy difference (trange) must be ginned up to
685: * correspond to the change reported in the other file.
686: */
687: static void
688: keep(int i, struct range *rnew)
689: {
690: int delta;
691: struct range trange;
692:
693: delta = last[3] - last[i];
694: trange.from = rnew->from - delta;
695: trange.to = rnew->to - delta;
696: change(i, &trange, 1);
697: }
698:
699: /*
700: * skip to just before line number from in file "i". If "pr" is non-NULL,
701: * print all skipped stuff with string pr as a prefix.
702: */
703: static int
704: skip(int i, int from, char *pr)
705: {
706: size_t j, n;
707: char *line;
708:
709: for (n = 0; cline[i] < from - 1; n += j) {
710: if ((line = getline(fp[i], &j)) == NULL)
711: return (-1);
712: if (pr != NULL)
713: diff_output("%s%s", pr, line);
714: cline[i]++;
715: }
716: return ((int) n);
717: }
718:
719: /*
720: * Return 1 or 0 according as the old range (in file 1) contains exactly
721: * the same data as the new range (in file 2).
722: */
723: static int
724: duplicate(struct range *r1, struct range *r2)
725: {
726: int c,d;
727: int nchar;
728: int nline;
729:
730: if (r1->to-r1->from != r2->to-r2->from)
731: return (0);
732: (void)skip(0, r1->from, NULL);
733: (void)skip(1, r2->from, NULL);
734: nchar = 0;
735: for (nline=0; nline < r1->to - r1->from; nline++) {
736: do {
737: c = getc(fp[0]);
738: d = getc(fp[1]);
739: if (c == -1 || d== -1)
740: return (-1);
741: nchar++;
742: if (c != d) {
743: repos(nchar);
744: return (0);
745: }
746: } while (c != '\n');
747: }
748: repos(nchar);
749: return (1);
750: }
751:
752: static void
753: repos(int nchar)
754: {
755: int i;
756:
757: for (i = 0; i < 2; i++)
1.38 tobias 758: (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
1.1 joris 759: }
760:
761: /*
762: * collect an editing script for later regurgitation
763: */
764: static int
765: edit(struct diff *diff, int fdup, int j)
766: {
767: if (((fdup + 1) & eflag) == 0)
768: return (j);
769: j++;
770: overlap[j] = !fdup;
771: if (!fdup)
772: overlapcnt++;
773: de[j].old.from = diff->old.from;
774: de[j].old.to = diff->old.to;
775: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
776: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
777: return (j);
778: }
779:
780: /* regurgitate */
781: static int
782: edscript(int n)
783: {
784: int j, k;
1.2 joris 785: char block[BUFSIZ+1];
1.1 joris 786:
787: for (n = n; n > 0; n--) {
788: if (!oflag || !overlap[n])
789: prange(&de[n].old);
790: else
791: diff_output("%da\n=======\n", de[n].old.to -1);
1.38 tobias 792: (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);
1.1 joris 793: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
794: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 795: if (fread(block, (size_t)1, (size_t)j,
796: fp[2]) != (size_t)j)
1.1 joris 797: return (-1);
798: block[j] = '\0';
799: diff_output("%s", block);
800: }
1.2 joris 801:
1.1 joris 802: if (!oflag || !overlap[n])
803: diff_output(".\n");
804: else {
805: diff_output("%s\n.\n", f3mark);
806: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
807: }
808: }
809:
810: return (overlapcnt);
811: }
812:
813: static void
814: increase(void)
815: {
816: size_t newsz, incr;
817:
818: /* are the memset(3) calls needed? */
819: newsz = szchanges == 0 ? 64 : 2 * szchanges;
820: incr = newsz - szchanges;
821:
1.36 ray 822: d13 = xrealloc(d13, newsz, sizeof(*d13));
823: memset(d13 + szchanges, 0, incr * sizeof(*d13));
824: d23 = xrealloc(d23, newsz, sizeof(*d23));
825: memset(d23 + szchanges, 0, incr * sizeof(*d23));
826: de = xrealloc(de, newsz, sizeof(*de));
827: memset(de + szchanges, 0, incr * sizeof(*de));
828: overlap = xrealloc(overlap, newsz, sizeof(*overlap));
829: memset(overlap + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 830: szchanges = newsz;
831: }
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