Annotation of src/usr.bin/cvs/diff3.c, Revision 1.47
1.47 ! joris 1: /* $OpenBSD: diff3.c,v 1.46 2008/03/08 11:53:36 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[] =
1.47 ! joris 75: "$OpenBSD: diff3.c,v 1.46 2008/03/08 11:53:36 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:
1.47 ! joris 118: static struct diff *d13 = NULL;
! 119: static struct diff *d23 = NULL;
1.1 joris 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: */
1.47 ! joris 128: static struct diff *de = NULL;
! 129: static char *overlap = NULL;
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;
1.47 ! joris 162: RCSNUM *d3rev1 = NULL;
! 163: RCSNUM *d3rev2 = NULL;
1.4 joris 164:
1.42 joris 165: static int fds[5];
166:
1.33 joris 167: void
168: cvs_merge_file(struct cvs_file *cf, int verbose)
1.1 joris 169: {
1.42 joris 170: int i, argc;
1.1 joris 171: char *data, *patch;
1.37 xsa 172: char *argv[5], r1[CVS_REV_BUFSZ], r2[CVS_REV_BUFSZ];
1.28 xsa 173: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 174: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
1.30 niallo 175: size_t dlen, plen;
1.33 joris 176: struct cvs_line *lp;
177: struct cvs_lines *dlines, *plines;
1.1 joris 178:
1.41 joris 179: overlapcnt = 0;
1.1 joris 180: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.47 ! joris 181:
! 182: rcsnum_tostr(d3rev1, r1, sizeof(r1));
! 183: rcsnum_tostr(d3rev2, r2, sizeof(r2));
1.1 joris 184:
1.40 tobias 185: b1 = cvs_buf_load_fd(cf->fd);
186: d1 = cvs_buf_alloc(128);
187: d2 = cvs_buf_alloc(128);
188: diffb = cvs_buf_alloc(128);
1.1 joris 189:
1.28 xsa 190: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
191: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
192: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
193:
1.42 joris 194: fds[2] = cvs_buf_write_stmp(b1, path1, NULL);
1.32 niallo 195: if (verbose == 1)
196: cvs_printf("Retrieving revision %s\n", r1);
1.47 ! joris 197: fds[3] = rcs_rev_write_stmp(cf->file_rcs, d3rev1, path2, 0);
1.32 niallo 198: if (verbose == 1)
199: cvs_printf("Retrieving revision %s\n", r2);
1.47 ! joris 200: fds[4] = rcs_rev_write_stmp(cf->file_rcs, d3rev2, path3, 0);
1.1 joris 201:
1.42 joris 202: cvs_diffreg(path1, path3, fds[2], fds[4], d1);
203: cvs_diffreg(path2, path3, fds[3], fds[4], d2);
1.1 joris 204:
1.28 xsa 205: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.42 joris 206: fds[0] = cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 207: cvs_buf_free(d1);
208:
1.28 xsa 209: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.42 joris 210: fds[1] = cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 211: cvs_buf_free(d2);
212:
213: argc = 0;
214: diffbuf = diffb;
215: argv[argc++] = dp13;
216: argv[argc++] = dp23;
217: argv[argc++] = path1;
218: argv[argc++] = path2;
219: argv[argc++] = path3;
1.7 joris 220:
1.46 joris 221: if (lseek(fds[2], 0, SEEK_SET) < 0)
1.42 joris 222: fatal("cvs_merge_file: lseek fds[2]: %s", strerror(errno));
1.46 joris 223: if (lseek(fds[3], 0, SEEK_SET) < 0)
1.42 joris 224: fatal("cvs_merge_file: lseek fds[3]: %s", strerror(errno));
1.46 joris 225: if (lseek(fds[4], 0, SEEK_SET) < 0)
1.42 joris 226: fatal("cvs_merge_file: lseek fds[4]: %s", strerror(errno));
227:
1.33 joris 228: diff3_conflicts = diff3_internal(argc, argv, cf->file_path, r2);
229: if (diff3_conflicts < 0)
230: fatal("cvs_merge_file: merging failed for an unknown reason");
1.1 joris 231:
1.30 niallo 232: plen = cvs_buf_len(diffb);
1.1 joris 233: patch = cvs_buf_release(diffb);
1.30 niallo 234: dlen = cvs_buf_len(b1);
1.1 joris 235: data = cvs_buf_release(b1);
236:
1.47 ! joris 237: if (verbose == 1)
! 238: cvs_printf("Merging differences between %s and %s into `%s'\n",
! 239: r1, r2, cf->file_path);
1.33 joris 240:
241: dlines = cvs_splitlines(data, dlen);
242: plines = cvs_splitlines(patch, plen);
1.47 ! joris 243:
1.33 joris 244: ed_patch_lines(dlines, plines);
245: cvs_freelines(plines);
1.7 joris 246:
1.23 deraadt 247: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 248: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 249: "please correct.", diff3_conflicts,
1.11 reyk 250: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 251: }
1.1 joris 252:
1.42 joris 253: (void)close(cf->fd);
1.45 joris 254: cf->fd = open(cf->file_path, O_CREAT | O_RDWR | O_TRUNC, 0644);
1.42 joris 255: if (cf->fd == -1) {
256: fatal("cvs_merge_file: failed to reopen fd for writing: %s",
257: strerror(errno));
258: }
259:
1.33 joris 260: TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) {
261: if (lp->l_line == NULL)
262: continue;
263:
1.39 tobias 264: if (atomicio(vwrite, cf->fd, lp->l_line, lp->l_len) !=
265: lp->l_len)
1.33 joris 266: fatal("cvs_merge_file: %s", strerror(errno));
267: }
268:
269: cvs_freelines(dlines);
270:
271: if (data != NULL)
272: xfree(data);
1.8 joris 273: xfree(patch);
1.1 joris 274:
1.42 joris 275: for (i = 0; i < 3; i++)
276: fclose(fp[i]);
277:
1.47 ! joris 278: cvs_worklist_run(&temp_files, cvs_worklist_unlink);
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: eflag = 3;
294: oflag = 1;
295:
296: if (argc < 5)
297: return (-1);
298:
1.34 xsa 299: (void)xsnprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
300: (void)xsnprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
1.1 joris 301:
1.47 ! joris 302: szchanges = 0;
! 303: memset(last, 0, sizeof(last));
! 304: memset(cline, 0, sizeof(cline));
! 305: if (d13 != NULL)
! 306: xfree(d13);
! 307: if (d23 != NULL)
! 308: xfree(d23);
! 309: if (overlap != NULL)
! 310: xfree(overlap);
! 311: if (de != NULL)
! 312: xfree(de);
! 313:
! 314: overlap = NULL;
! 315: de = d13 = d23 = NULL;
! 316:
1.1 joris 317: increase();
1.42 joris 318:
319: /* fds[0] and fds[1] are closed in readin() */
320: m = readin(fds[0], &d13);
321: n = readin(fds[1], &d23);
1.1 joris 322:
323: for (i = 0; i <= 2; i++) {
1.42 joris 324: if ((fp[i] = fdopen(fds[i + 2], "r")) == NULL) {
1.24 joris 325: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 326: return (-1);
327: }
328: }
329:
330: return (merge(m, n));
331: }
332:
333: int
334: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
335: {
1.47 ! joris 336: char op, *ep, *p;
1.29 xsa 337: struct cvs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.19 xsa 338: int start, end, i, lineno;
1.30 niallo 339: u_char tmp;
1.1 joris 340:
341: dlp = TAILQ_FIRST(&(dlines->l_lines));
342: lp = TAILQ_FIRST(&(plines->l_lines));
343:
1.19 xsa 344: end = 0;
1.1 joris 345: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
346: lp = TAILQ_NEXT(lp, l_list)) {
1.30 niallo 347: /* Skip blank lines */
348: if (lp->l_len < 2)
349: continue;
1.47 ! joris 350:
1.30 niallo 351: /* NUL-terminate line buffer for strtol() safety. */
352: tmp = lp->l_line[lp->l_len - 1];
353: lp->l_line[lp->l_len - 1] = '\0';
1.47 ! joris 354:
1.1 joris 355: op = lp->l_line[strlen(lp->l_line) - 1];
356: start = (int)strtol(lp->l_line, &ep, 10);
1.47 ! joris 357:
1.30 niallo 358: /* Restore the last byte of the buffer */
359: lp->l_line[lp->l_len - 1] = tmp;
1.47 ! joris 360:
1.1 joris 361: if (op == 'a') {
1.23 deraadt 362: if (start > dlines->l_nblines ||
363: start < 0 || *ep != 'a')
1.47 ! joris 364: fatal("ed_patch_lines %d", start);
1.1 joris 365: } else if (op == 'c') {
1.23 deraadt 366: if (start > dlines->l_nblines ||
367: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 368: fatal("ed_patch_lines");
1.1 joris 369:
1.2 joris 370: if (*ep == ',') {
371: ep++;
372: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 373: if (end < 0 || *ep != 'c')
1.15 niallo 374: fatal("ed_patch_lines");
1.2 joris 375: } else {
376: end = start;
377: }
1.47 ! joris 378: } else {
! 379: fatal("invalid op %c found while merging", op);
1.1 joris 380: }
381:
1.2 joris 382:
1.1 joris 383: for (;;) {
384: if (dlp == NULL)
385: break;
386: if (dlp->l_lineno == start)
387: break;
388: if (dlp->l_lineno > start) {
389: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
390: } else if (dlp->l_lineno < start) {
391: ndlp = TAILQ_NEXT(dlp, l_list);
392: if (ndlp->l_lineno > start)
393: break;
394: dlp = ndlp;
395: }
396: }
397:
398: if (dlp == NULL)
1.15 niallo 399: fatal("ed_patch_lines");
1.1 joris 400:
1.2 joris 401:
1.1 joris 402: if (op == 'c') {
1.29 xsa 403: insert_after = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.2 joris 404: for (i = 0; i <= (end - start); i++) {
1.1 joris 405: ndlp = TAILQ_NEXT(dlp, l_list);
406: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
407: dlp = ndlp;
408: }
1.29 xsa 409: dlp = insert_after;
1.1 joris 410: }
411:
412: if (op == 'a' || op == 'c') {
413: for (;;) {
414: ndlp = lp;
415: lp = TAILQ_NEXT(lp, l_list);
416: if (lp == NULL)
1.15 niallo 417: fatal("ed_patch_lines");
1.1 joris 418:
1.47 ! joris 419: if (lp->l_len == 2 &&
! 420: lp->l_line[0] == '.' &&
! 421: lp->l_line[1] == '\n')
1.1 joris 422: break;
423:
424: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
425: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
426: lp, l_list);
427: dlp = lp;
428:
429: lp->l_lineno = start;
430: lp = ndlp;
431: }
432: }
433:
434: /*
435: * always resort lines as the markers might be put at the
436: * same line as we first started editing.
437: */
438: lineno = 0;
439: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
440: sort->l_lineno = lineno++;
441: dlines->l_nblines = lineno - 1;
442: }
443:
444: return (0);
445: }
446:
447: /*
448: * Pick up the line numbers of all changes from one change file.
449: * (This puts the numbers in a vector, which is not strictly necessary,
450: * since the vector is processed in one sequential pass.
451: * The vector could be optimized out of existence)
452: */
1.20 ray 453: static size_t
1.42 joris 454: readin(int fd, struct diff **dd)
1.1 joris 455: {
456: int a, b, c, d;
457: char kind, *p;
458: size_t i;
459:
1.42 joris 460: fp[0] = fdopen(fd, "r");
461: if (fp[0] == NULL)
462: fatal("readin: fdopen: %s", strerror(errno));
463:
1.1 joris 464: for (i = 0; (p = getchange(fp[0])); i++) {
465: if (i >= szchanges - 1)
466: increase();
467: a = b = number(&p);
468: if (*p == ',') {
469: p++;
470: b = number(&p);
471: }
472: kind = *p++;
473: c = d = number(&p);
474: if (*p==',') {
475: p++;
476: d = number(&p);
477: }
478: if (kind == 'a')
479: a++;
480: if (kind == 'd')
481: c++;
482: b++;
483: d++;
484: (*dd)[i].old.from = a;
485: (*dd)[i].old.to = b;
486: (*dd)[i].new.from = c;
487: (*dd)[i].new.to = d;
488: }
489:
1.14 xsa 490: if (i) {
491: (*dd)[i].old.from = (*dd)[i-1].old.to;
492: (*dd)[i].new.from = (*dd)[i-1].new.to;
493: }
1.42 joris 494:
1.1 joris 495: (void)fclose(fp[0]);
496:
497: return (i);
498: }
499:
500: static int
501: number(char **lc)
502: {
503: int nn;
504:
505: nn = 0;
506: while (isdigit((unsigned char)(**lc)))
507: nn = nn*10 + *(*lc)++ - '0';
508:
509: return (nn);
510: }
511:
512: static char *
513: getchange(FILE *b)
514: {
515: char *line;
516:
517: while ((line = getline(b, NULL))) {
518: if (isdigit((unsigned char)line[0]))
519: return (line);
520: }
521:
522: return (NULL);
523: }
524:
525: static char *
526: getline(FILE *b, size_t *n)
527: {
528: char *cp;
529: size_t len;
530: static char *buf;
531: static size_t bufsize;
532:
533: if ((cp = fgetln(b, &len)) == NULL)
534: return (NULL);
535:
536: if (cp[len - 1] != '\n')
537: len++;
538: if (len + 1 > bufsize) {
539: do {
540: bufsize += 1024;
541: } while (len + 1 > bufsize);
1.36 ray 542: buf = xrealloc(buf, 1, bufsize);
1.1 joris 543: }
544: memcpy(buf, cp, len - 1);
545: buf[len - 1] = '\n';
546: buf[len] = '\0';
547: if (n != NULL)
548: *n = len;
549:
550: return (buf);
551: }
552:
553: static int
1.20 ray 554: merge(size_t m1, size_t m2)
1.1 joris 555: {
556: struct diff *d1, *d2, *d3;
557: int dpl, j, t1, t2;
558:
559: d1 = d13;
560: d2 = d23;
561: j = 0;
562: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
563: if (debug) {
564: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 565: d1->old.from, d1->old.to,
566: d1->new.from, d1->new.to,
567: d2->old.from, d2->old.to,
568: d2->new.from, d2->new.to);
1.1 joris 569: }
570:
571: /* first file is different from others */
572: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
573: /* stuff peculiar to 1st file */
574: if (eflag==0) {
575: separate("1");
576: change(1, &d1->old, 0);
577: keep(2, &d1->new);
578: change(3, &d1->new, 0);
579: }
580: d1++;
581: continue;
582: }
583:
584: /* second file is different from others */
585: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
586: if (eflag==0) {
587: separate("2");
588: keep(1, &d2->new);
589: change(2, &d2->old, 0);
590: change(3, &d2->new, 0);
591: }
592: d2++;
593: continue;
594: }
595:
596: /*
597: * Merge overlapping changes in first file
598: * this happens after extension (see below).
599: */
600: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
601: d1[1].old.from = d1->old.from;
602: d1[1].new.from = d1->new.from;
603: d1++;
604: continue;
605: }
606:
607: /* merge overlapping changes in second */
608: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
609: d2[1].old.from = d2->old.from;
610: d2[1].new.from = d2->new.from;
611: d2++;
612: continue;
613: }
614: /* stuff peculiar to third file or different in all */
615: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
616: dpl = duplicate(&d1->old,&d2->old);
617: if (dpl == -1)
618: return (-1);
619:
620: /*
621: * dpl = 0 means all files differ
622: * dpl = 1 means files 1 and 2 identical
623: */
624: if (eflag==0) {
625: separate(dpl ? "3" : "");
626: change(1, &d1->old, dpl);
627: change(2, &d2->old, 0);
628: d3 = d1->old.to > d1->old.from ? d1 : d2;
629: change(3, &d3->new, 0);
630: } else
631: j = edit(d1, dpl, j);
632: d1++;
633: d2++;
634: continue;
635: }
636:
637: /*
638: * Overlapping changes from file 1 and 2; extend changes
639: * appropriately to make them coincide.
640: */
641: if (d1->new.from < d2->new.from) {
642: d2->old.from -= d2->new.from-d1->new.from;
643: d2->new.from = d1->new.from;
644: } else if (d2->new.from < d1->new.from) {
645: d1->old.from -= d1->new.from-d2->new.from;
646: d1->new.from = d2->new.from;
647: }
648: if (d1->new.to > d2->new.to) {
649: d2->old.to += d1->new.to - d2->new.to;
650: d2->new.to = d1->new.to;
651: } else if (d2->new.to > d1->new.to) {
652: d1->old.to += d2->new.to - d1->new.to;
653: d1->new.to = d2->new.to;
654: }
655: }
656:
657: return (edscript(j));
658: }
659:
660: static void
661: separate(const char *s)
662: {
663: diff_output("====%s\n", s);
664: }
665:
666: /*
667: * The range of lines rold.from thru rold.to in file i is to be changed.
668: * It is to be printed only if it does not duplicate something to be
669: * printed later.
670: */
671: static void
672: change(int i, struct range *rold, int fdup)
673: {
674: diff_output("%d:", i);
675: last[i] = rold->to;
676: prange(rold);
677: if (fdup || debug)
678: return;
679: i--;
680: (void)skip(i, rold->from, NULL);
681: (void)skip(i, rold->to, " ");
682: }
683:
684: /*
685: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
686: */
687: static void
688: prange(struct range *rold)
689: {
690: if (rold->to <= rold->from)
691: diff_output("%da\n", rold->from - 1);
692: else {
693: diff_output("%d", rold->from);
694: if (rold->to > rold->from+1)
695: diff_output(",%d", rold->to - 1);
696: diff_output("c\n");
697: }
698: }
699:
700: /*
701: * No difference was reported by diff between file 1 (or 2) and file 3,
702: * and an artificial dummy difference (trange) must be ginned up to
703: * correspond to the change reported in the other file.
704: */
705: static void
706: keep(int i, struct range *rnew)
707: {
708: int delta;
709: struct range trange;
710:
711: delta = last[3] - last[i];
712: trange.from = rnew->from - delta;
713: trange.to = rnew->to - delta;
714: change(i, &trange, 1);
715: }
716:
717: /*
718: * skip to just before line number from in file "i". If "pr" is non-NULL,
719: * print all skipped stuff with string pr as a prefix.
720: */
721: static int
722: skip(int i, int from, char *pr)
723: {
724: size_t j, n;
725: char *line;
726:
727: for (n = 0; cline[i] < from - 1; n += j) {
728: if ((line = getline(fp[i], &j)) == NULL)
729: return (-1);
730: if (pr != NULL)
731: diff_output("%s%s", pr, line);
732: cline[i]++;
733: }
734: return ((int) n);
735: }
736:
737: /*
738: * Return 1 or 0 according as the old range (in file 1) contains exactly
739: * the same data as the new range (in file 2).
740: */
741: static int
742: duplicate(struct range *r1, struct range *r2)
743: {
744: int c,d;
745: int nchar;
746: int nline;
747:
748: if (r1->to-r1->from != r2->to-r2->from)
749: return (0);
750: (void)skip(0, r1->from, NULL);
751: (void)skip(1, r2->from, NULL);
752: nchar = 0;
753: for (nline=0; nline < r1->to - r1->from; nline++) {
754: do {
755: c = getc(fp[0]);
756: d = getc(fp[1]);
757: if (c == -1 || d== -1)
758: return (-1);
759: nchar++;
760: if (c != d) {
761: repos(nchar);
762: return (0);
763: }
764: } while (c != '\n');
765: }
766: repos(nchar);
767: return (1);
768: }
769:
770: static void
771: repos(int nchar)
772: {
773: int i;
774:
775: for (i = 0; i < 2; i++)
1.38 tobias 776: (void)fseek(fp[i], (long)-nchar, SEEK_CUR);
1.1 joris 777: }
778:
779: /*
780: * collect an editing script for later regurgitation
781: */
782: static int
783: edit(struct diff *diff, int fdup, int j)
784: {
785: if (((fdup + 1) & eflag) == 0)
786: return (j);
787: j++;
788: overlap[j] = !fdup;
789: if (!fdup)
790: overlapcnt++;
791: de[j].old.from = diff->old.from;
792: de[j].old.to = diff->old.to;
793: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
794: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
795: return (j);
796: }
797:
798: /* regurgitate */
799: static int
800: edscript(int n)
801: {
802: int j, k;
1.2 joris 803: char block[BUFSIZ+1];
1.1 joris 804:
805: for (n = n; n > 0; n--) {
806: if (!oflag || !overlap[n])
807: prange(&de[n].old);
808: else
809: diff_output("%da\n=======\n", de[n].old.to -1);
1.38 tobias 810: (void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);
1.1 joris 811: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
812: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 813: if (fread(block, (size_t)1, (size_t)j,
814: fp[2]) != (size_t)j)
1.1 joris 815: return (-1);
816: block[j] = '\0';
817: diff_output("%s", block);
818: }
1.2 joris 819:
1.1 joris 820: if (!oflag || !overlap[n])
821: diff_output(".\n");
822: else {
823: diff_output("%s\n.\n", f3mark);
824: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
825: }
826: }
827:
828: return (overlapcnt);
829: }
830:
831: static void
832: increase(void)
833: {
834: size_t newsz, incr;
835:
836: /* are the memset(3) calls needed? */
837: newsz = szchanges == 0 ? 64 : 2 * szchanges;
838: incr = newsz - szchanges;
839:
1.36 ray 840: d13 = xrealloc(d13, newsz, sizeof(*d13));
841: memset(d13 + szchanges, 0, incr * sizeof(*d13));
842: d23 = xrealloc(d23, newsz, sizeof(*d23));
843: memset(d23 + szchanges, 0, incr * sizeof(*d23));
844: de = xrealloc(de, newsz, sizeof(*de));
845: memset(de + szchanges, 0, incr * sizeof(*de));
846: overlap = xrealloc(overlap, newsz, sizeof(*overlap));
847: memset(overlap + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 848: szchanges = newsz;
849: }
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