Annotation of src/usr.bin/cvs/diff3.c, Revision 1.52
1.52 ! ray 1: /* $OpenBSD: diff3.c,v 1.51 2009/10/27 23:59:37 deraadt 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:
1.35 otto 67: #include <ctype.h>
68: #include <errno.h>
69: #include <fcntl.h>
1.38 tobias 70: #include <stdio.h>
1.35 otto 71: #include <stdlib.h>
72: #include <string.h>
73: #include <unistd.h>
1.1 joris 74:
1.39 tobias 75: #include "atomicio.h"
1.1 joris 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:
1.47 joris 107: static struct diff *d13 = NULL;
108: static struct diff *d23 = NULL;
1.1 joris 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: */
1.47 joris 117: static struct diff *de = NULL;
118: static char *overlap = NULL;
1.2 joris 119: static int overlapcnt = 0;
1.1 joris 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;
1.33 joris 131: static char f1mark[MAXPATHLEN], f3mark[MAXPATHLEN]; /* markers for -E and -X */
1.1 joris 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 *getline(FILE *, size_t *);
137: static int number(char **);
1.42 joris 138: static size_t readin(int, struct diff **);
1.1 joris 139: static int skip(int, int, char *);
140: static int edscript(int);
1.20 ray 141: static int merge(size_t, size_t);
1.1 joris 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:
1.5 xsa 150: int diff3_conflicts = 0;
1.47 joris 151: RCSNUM *d3rev1 = NULL;
152: RCSNUM *d3rev2 = NULL;
1.4 joris 153:
1.42 joris 154: static int fds[5];
155:
1.33 joris 156: void
157: cvs_merge_file(struct cvs_file *cf, int verbose)
1.1 joris 158: {
1.42 joris 159: int i, argc;
1.1 joris 160: char *data, *patch;
1.37 xsa 161: char *argv[5], r1[CVS_REV_BUFSZ], r2[CVS_REV_BUFSZ];
1.28 xsa 162: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 163: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
1.30 niallo 164: size_t dlen, plen;
1.33 joris 165: struct cvs_line *lp;
166: struct cvs_lines *dlines, *plines;
1.1 joris 167:
1.41 joris 168: overlapcnt = 0;
1.1 joris 169: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.47 joris 170:
171: rcsnum_tostr(d3rev1, r1, sizeof(r1));
172: rcsnum_tostr(d3rev2, r2, sizeof(r2));
1.1 joris 173:
1.40 tobias 174: b1 = cvs_buf_load_fd(cf->fd);
175: d1 = cvs_buf_alloc(128);
176: d2 = cvs_buf_alloc(128);
177: diffb = cvs_buf_alloc(128);
1.1 joris 178:
1.28 xsa 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:
1.42 joris 183: fds[2] = cvs_buf_write_stmp(b1, path1, NULL);
1.32 niallo 184: if (verbose == 1)
185: cvs_printf("Retrieving revision %s\n", r1);
1.47 joris 186: fds[3] = rcs_rev_write_stmp(cf->file_rcs, d3rev1, path2, 0);
1.32 niallo 187: if (verbose == 1)
188: cvs_printf("Retrieving revision %s\n", r2);
1.47 joris 189: fds[4] = rcs_rev_write_stmp(cf->file_rcs, d3rev2, path3, 0);
1.1 joris 190:
1.50 ray 191: diffreg(path1, path3, fds[2], fds[4], d1, D_FORCEASCII);
192: diffreg(path2, path3, fds[3], fds[4], d2, D_FORCEASCII);
1.1 joris 193:
1.28 xsa 194: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.42 joris 195: fds[0] = cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 196: cvs_buf_free(d1);
197:
1.28 xsa 198: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.42 joris 199: fds[1] = cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 200: cvs_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;
1.7 joris 209:
1.46 joris 210: if (lseek(fds[2], 0, SEEK_SET) < 0)
1.42 joris 211: fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno));
1.46 joris 212: if (lseek(fds[3], 0, SEEK_SET) < 0)
1.42 joris 213: fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno));
1.46 joris 214: if (lseek(fds[4], 0, SEEK_SET) < 0)
1.42 joris 215: fatal("cvs_merge_file: lseek fds[4]: %s", strerror(errno));
216:
1.33 joris 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");
1.1 joris 220:
1.30 niallo 221: plen = cvs_buf_len(diffb);
1.1 joris 222: patch = cvs_buf_release(diffb);
1.30 niallo 223: dlen = cvs_buf_len(b1);
1.1 joris 224: data = cvs_buf_release(b1);
225:
1.47 joris 226: if (verbose == 1)
227: cvs_printf("Merging differences between %s and %s into `%s'\n",
228: r1, r2, cf->file_path);
1.33 joris 229:
230: dlines = cvs_splitlines(data, dlen);
231: plines = cvs_splitlines(patch, plen);
1.47 joris 232:
1.33 joris 233: ed_patch_lines(dlines, plines);
234: cvs_freelines(plines);
1.7 joris 235:
1.23 deraadt 236: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 237: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 238: "please correct.", diff3_conflicts,
1.11 reyk 239: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 240: }
1.1 joris 241:
1.42 joris 242: (void)close(cf->fd);
1.45 joris 243: cf->fd = open(cf->file_path, O_CREAT | O_RDWR | O_TRUNC, 0644);
1.42 joris 244: if (cf->fd == -1) {
245: fatal("cvs_merge_file: failed to reopen fd for writing: %s",
246: strerror(errno));
247: }
248:
1.33 joris 249: TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) {
250: if (lp->l_line == NULL)
251: continue;
252:
1.39 tobias 253: if (atomicio(vwrite, cf->fd, lp->l_line, lp->l_len) !=
254: lp->l_len)
1.33 joris 255: fatal("cvs_merge_file: %s", strerror(errno));
256: }
257:
258: cvs_freelines(dlines);
259:
260: if (data != NULL)
261: xfree(data);
1.8 joris 262: xfree(patch);
1.1 joris 263:
1.42 joris 264: for (i = 0; i < 3; i++)
265: fclose(fp[i]);
266:
1.52 ! ray 267: worklist_run(&temp_files, worklist_unlink);
1.28 xsa 268:
1.33 joris 269: xfree(path1);
270: xfree(path2);
271: xfree(path3);
272: xfree(dp13);
273: xfree(dp23);
1.1 joris 274: }
275:
276: static int
277: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
278: {
1.20 ray 279: size_t m, n;
280: int i;
1.1 joris 281:
282: eflag = 3;
283: oflag = 1;
284:
285: if (argc < 5)
286: return (-1);
287:
1.34 xsa 288: (void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
289: (void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
1.1 joris 290:
1.47 joris 291: szchanges = 0;
292: memset(last, 0, sizeof(last));
293: memset(cline, 0, sizeof(cline));
294: if (d13 != NULL)
295: xfree(d13);
296: if (d23 != NULL)
297: xfree(d23);
298: if (overlap != NULL)
299: xfree(overlap);
300: if (de != NULL)
301: xfree(de);
302:
303: overlap = NULL;
304: de = d13 = d23 = NULL;
305:
1.1 joris 306: increase();
1.42 joris 307:
308: /* fds[0] and fds[1] are closed in readin() */
309: m = readin(fds[0], &d13);
310: n = readin(fds[1], &d23);
1.1 joris 311:
312: for (i = 0; i <= 2; i++) {
1.42 joris 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: {
1.48 joris 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;
1.47 joris 339:
1.30 niallo 340: /* NUL-terminate line buffer for strtol() safety. */
341: tmp = lp->l_line[lp->l_len - 1];
342: lp->l_line[lp->l_len - 1] = '\0';
1.47 joris 343:
1.1 joris 344: op = lp->l_line[strlen(lp->l_line) - 1];
345: start = (int)strtol(lp->l_line, &ep, 10);
1.47 joris 346:
1.30 niallo 347: /* Restore the last byte of the buffer */
348: lp->l_line[lp->l_len - 1] = tmp;
1.47 joris 349:
1.1 joris 350: if (op == 'a') {
1.23 deraadt 351: if (start > dlines->l_nblines ||
352: start < 0 || *ep != 'a')
1.47 joris 353: fatal("ed_patch_lines %d", start);
1.1 joris 354: } else if (op == 'c') {
1.23 deraadt 355: if (start > dlines->l_nblines ||
356: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 357: fatal("ed_patch_lines");
1.1 joris 358:
1.2 joris 359: if (*ep == ',') {
360: ep++;
361: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 362: if (end < 0 || *ep != 'c')
1.15 niallo 363: fatal("ed_patch_lines");
1.2 joris 364: } else {
365: end = start;
366: }
1.47 joris 367: } else {
368: fatal("invalid op %c found while merging", op);
1.1 joris 369: }
370:
1.2 joris 371:
1.1 joris 372: for (;;) {
373: if (dlp == NULL)
374: break;
375: if (dlp->l_lineno == start)
376: break;
377: if (dlp->l_lineno > start) {
1.52 ! ray 378: dlp = TAILQ_PREV(dlp, tqh, l_list);
1.1 joris 379: } else if (dlp->l_lineno < start) {
380: ndlp = TAILQ_NEXT(dlp, l_list);
381: if (ndlp->l_lineno > start)
382: break;
383: dlp = ndlp;
384: }
385: }
386:
387: if (dlp == NULL)
1.15 niallo 388: fatal("ed_patch_lines");
1.1 joris 389:
1.2 joris 390:
1.1 joris 391: if (op == 'c') {
1.52 ! ray 392: insert_after = TAILQ_PREV(dlp, tqh, l_list);
1.2 joris 393: for (i = 0; i <= (end - start); i++) {
1.1 joris 394: ndlp = TAILQ_NEXT(dlp, l_list);
395: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
396: dlp = ndlp;
397: }
1.29 xsa 398: dlp = insert_after;
1.1 joris 399: }
400:
401: if (op == 'a' || op == 'c') {
402: for (;;) {
403: ndlp = lp;
404: lp = TAILQ_NEXT(lp, l_list);
405: if (lp == NULL)
1.15 niallo 406: fatal("ed_patch_lines");
1.1 joris 407:
1.47 joris 408: if (lp->l_len == 2 &&
409: lp->l_line[0] == '.' &&
410: lp->l_line[1] == '\n')
1.1 joris 411: break;
412:
413: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
414: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
415: lp, l_list);
416: dlp = lp;
417:
418: lp->l_lineno = start;
419: lp = ndlp;
420: }
421: }
422:
423: /*
424: * always resort lines as the markers might be put at the
425: * same line as we first started editing.
426: */
427: lineno = 0;
428: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
429: sort->l_lineno = lineno++;
430: dlines->l_nblines = lineno - 1;
431: }
432:
433: return (0);
434: }
435:
436: /*
437: * Pick up the line numbers of all changes from one change file.
438: * (This puts the numbers in a vector, which is not strictly necessary,
439: * since the vector is processed in one sequential pass.
440: * The vector could be optimized out of existence)
441: */
1.20 ray 442: static size_t
1.42 joris 443: readin(int fd, struct diff **dd)
1.1 joris 444: {
445: int a, b, c, d;
446: char kind, *p;
447: size_t i;
448:
1.42 joris 449: fp[0] = fdopen(fd, "r");
450: if (fp[0] == NULL)
451: fatal("readin: fdopen: %s", strerror(errno));
452:
1.1 joris 453: for (i = 0; (p = getchange(fp[0])); i++) {
454: if (i >= szchanges - 1)
455: increase();
456: a = b = number(&p);
457: if (*p == ',') {
458: p++;
459: b = number(&p);
460: }
461: kind = *p++;
462: c = d = number(&p);
463: if (*p==',') {
464: p++;
465: d = number(&p);
466: }
467: if (kind == 'a')
468: a++;
469: if (kind == 'd')
470: c++;
471: b++;
472: d++;
473: (*dd)[i].old.from = a;
474: (*dd)[i].old.to = b;
475: (*dd)[i].new.from = c;
476: (*dd)[i].new.to = d;
477: }
478:
1.14 xsa 479: if (i) {
480: (*dd)[i].old.from = (*dd)[i-1].old.to;
481: (*dd)[i].new.from = (*dd)[i-1].new.to;
482: }
1.42 joris 483:
1.1 joris 484: (void)fclose(fp[0]);
485:
486: return (i);
487: }
488:
489: static int
490: number(char **lc)
491: {
492: int nn;
493:
494: nn = 0;
495: while (isdigit((unsigned char)(**lc)))
496: nn = nn*10 + *(*lc)++ - '0';
497:
498: return (nn);
499: }
500:
501: static char *
502: getchange(FILE *b)
503: {
504: char *line;
505:
506: while ((line = getline(b, NULL))) {
507: if (isdigit((unsigned char)line[0]))
508: return (line);
509: }
510:
511: return (NULL);
512: }
513:
514: static char *
515: getline(FILE *b, size_t *n)
516: {
517: char *cp;
518: size_t len;
519: static char *buf;
520: static size_t bufsize;
521:
522: if ((cp = fgetln(b, &len)) == NULL)
523: return (NULL);
524:
525: if (cp[len - 1] != '\n')
526: len++;
527: if (len + 1 > bufsize) {
528: do {
529: bufsize += 1024;
530: } while (len + 1 > bufsize);
1.36 ray 531: buf = xrealloc(buf, 1, bufsize);
1.1 joris 532: }
533: memcpy(buf, cp, len - 1);
534: buf[len - 1] = '\n';
535: buf[len] = '\0';
536: if (n != NULL)
537: *n = len;
538:
539: return (buf);
540: }
541:
542: static int
1.20 ray 543: merge(size_t m1, size_t m2)
1.1 joris 544: {
545: struct diff *d1, *d2, *d3;
546: int dpl, j, t1, t2;
547:
548: d1 = d13;
549: d2 = d23;
550: j = 0;
551: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
552: if (debug) {
553: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 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);
1.1 joris 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 = getline(fp[i], &j)) == NULL)
718: return (-1);
719: if (pr != NULL)
720: diff_output("%s%s", pr, line);
721: cline[i]++;
722: }
723: return ((int) n);
724: }
725:
726: /*
727: * Return 1 or 0 according as the old range (in file 1) contains exactly
728: * the same data as the new range (in file 2).
729: */
730: static int
731: duplicate(struct range *r1, struct range *r2)
732: {
733: int c,d;
734: int nchar;
735: int nline;
736:
737: if (r1->to-r1->from != r2->to-r2->from)
738: return (0);
739: (void)skip(0, r1->from, NULL);
740: (void)skip(1, r2->from, NULL);
741: nchar = 0;
742: for (nline=0; nline < r1->to - r1->from; nline++) {
743: do {
744: c = getc(fp[0]);
745: d = getc(fp[1]);
746: if (c == -1 || d== -1)
747: return (-1);
748: nchar++;
749: if (c != d) {
750: repos(nchar);
751: return (0);
752: }
753: } while (c != '\n');
754: }
755: repos(nchar);
756: return (1);
757: }
758:
759: static void
760: repos(int nchar)
761: {
762: int i;
763:
764: for (i = 0; i < 2; i++)
1.38 tobias 765: (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
1.1 joris 766: }
767:
768: /*
769: * collect an editing script for later regurgitation
770: */
771: static int
772: edit(struct diff *diff, int fdup, int j)
773: {
774: if (((fdup + 1) & eflag) == 0)
775: return (j);
776: j++;
777: overlap[j] = !fdup;
778: if (!fdup)
779: overlapcnt++;
780: de[j].old.from = diff->old.from;
781: de[j].old.to = diff->old.to;
782: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
783: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
784: return (j);
785: }
786:
787: /* regurgitate */
788: static int
789: edscript(int n)
790: {
791: int j, k;
1.2 joris 792: char block[BUFSIZ+1];
1.1 joris 793:
794: for (n = n; n > 0; n--) {
795: if (!oflag || !overlap[n])
796: prange(&de[n].old);
797: else
798: diff_output("%da\n=======\n", de[n].old.to -1);
1.38 tobias 799: (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);
1.1 joris 800: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
801: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 802: if (fread(block, (size_t)1, (size_t)j,
803: fp[2]) != (size_t)j)
1.1 joris 804: return (-1);
805: block[j] = '\0';
806: diff_output("%s", block);
807: }
1.2 joris 808:
1.1 joris 809: if (!oflag || !overlap[n])
810: diff_output(".\n");
811: else {
812: diff_output("%s\n.\n", f3mark);
813: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
814: }
815: }
816:
817: return (overlapcnt);
818: }
819:
820: static void
821: increase(void)
822: {
823: size_t newsz, incr;
824:
825: /* are the memset(3) calls needed? */
826: newsz = szchanges == 0 ? 64 : 2 * szchanges;
827: incr = newsz - szchanges;
828:
1.36 ray 829: d13 = xrealloc(d13, newsz, sizeof(*d13));
830: memset(d13 + szchanges, 0, incr * sizeof(*d13));
831: d23 = xrealloc(d23, newsz, sizeof(*d23));
832: memset(d23 + szchanges, 0, incr * sizeof(*d23));
833: de = xrealloc(de, newsz, sizeof(*de));
834: memset(de + szchanges, 0, incr * sizeof(*de));
835: overlap = xrealloc(overlap, newsz, sizeof(*overlap));
836: memset(overlap + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 837: szchanges = newsz;
838: }
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