Annotation of src/usr.bin/cvs/diff3.c, Revision 1.33
1.33 ! joris 1: /* $OpenBSD: diff3.c,v 1.32 2007/01/12 23:32:01 niallo 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[] =
1.33 ! joris 75: "$OpenBSD: diff3.c,v 1.32 2007/01/12 23:32:01 niallo Exp $";
1.1 joris 76: #endif /* not lint */
77:
1.12 xsa 78: #include "includes.h"
1.1 joris 79:
80: #include "cvs.h"
81: #include "log.h"
82: #include "diff.h"
83:
84: /* diff3 - 3-way differential file comparison */
85:
86: /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
87: *
88: * d13 = diff report on f1 vs f3
89: * d23 = diff report on f2 vs f3
90: * f1, f2, f3 the 3 files
91: * if changes in f1 overlap with changes in f3, m1 and m3 are used
92: * to mark the overlaps; otherwise, the file names f1 and f3 are used
93: * (only for options E and X).
94: */
95:
96: /*
97: * "from" is first in range of changed lines; "to" is last+1
98: * from=to=line after point of insertion for added lines.
99: */
100: struct range {
101: int from;
102: int to;
103: };
104:
105: struct diff {
106: struct range old;
107: struct range new;
108: };
109:
110: static size_t szchanges;
111:
112: static struct diff *d13;
113: static struct diff *d23;
114:
115: /*
116: * "de" is used to gather editing scripts. These are later spewed out in
117: * reverse order. Its first element must be all zero, the "new" component
118: * of "de" contains line positions or byte positions depending on when you
119: * look (!?). Array overlap indicates which sections in "de" correspond to
120: * lines that are different in all three files.
121: */
122: static struct diff *de;
123: static char *overlap;
1.2 joris 124: static int overlapcnt = 0;
1.1 joris 125: static FILE *fp[3];
126: static int cline[3]; /* # of the last-read line in each file (0-2) */
127:
128: /*
129: * the latest known correspondence between line numbers of the 3 files
130: * is stored in last[1-3];
131: */
132: static int last[4];
133: static int eflag;
134: static int oflag; /* indicates whether to mark overlaps (-E or -X)*/
135: static int debug = 0;
1.33 ! joris 136: static char f1mark[MAXPATHLEN], f3mark[MAXPATHLEN]; /* markers for -E and -X */
1.1 joris 137:
138: static int duplicate(struct range *, struct range *);
139: static int edit(struct diff *, int, int);
140: static char *getchange(FILE *);
141: static char *getline(FILE *, size_t *);
142: static int number(char **);
1.20 ray 143: static size_t readin(char *, struct diff **);
1.1 joris 144: static int skip(int, int, char *);
145: static int edscript(int);
1.20 ray 146: static int merge(size_t, size_t);
1.1 joris 147: static void change(int, struct range *, int);
148: static void keep(int, struct range *);
149: static void prange(struct range *);
150: static void repos(int);
151: static void separate(const char *);
152: static void increase(void);
153: static int diff3_internal(int, char **, const char *, const char *);
154:
1.5 xsa 155: int diff3_conflicts = 0;
1.4 joris 156:
1.33 ! joris 157: void
! 158: cvs_merge_file(struct cvs_file *cf, int verbose)
1.1 joris 159: {
1.19 xsa 160: int argc;
1.1 joris 161: char *data, *patch;
162: char *argv[5], r1[16], r2[16];
1.28 xsa 163: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 164: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
1.30 niallo 165: size_t dlen, plen;
1.33 ! joris 166: struct cvs_line *lp;
! 167: struct cvs_lines *dlines, *plines;
1.1 joris 168:
169: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.33 ! joris 170: rcsnum_tostr(cf->file_ent->ce_rev, r1, sizeof(r1));
! 171: rcsnum_tostr(cf->file_rcsrev, r2, sizeof(r2));
1.1 joris 172:
1.33 ! joris 173: b1 = cvs_buf_load_fd(cf->fd, BUF_AUTOEXT);
1.10 joris 174: d1 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
175: d2 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
176: diffb = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
1.1 joris 177:
1.33 ! joris 178: (void)close(cf->fd);
! 179: cf->fd = open(cf->file_path, O_WRONLY | O_TRUNC);
! 180: if (cf->fd == -1) {
! 181: fatal("cvs_merge_file: failed to reopen fd for writing: %s",
! 182: strerror(errno));
! 183: }
! 184:
1.28 xsa 185: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
186: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
187: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
188:
1.26 ray 189: cvs_buf_write_stmp(b1, path1, NULL);
1.32 niallo 190: if (verbose == 1)
191: cvs_printf("Retrieving revision %s\n", r1);
1.33 ! joris 192: rcs_rev_write_stmp(cf->file_rcs, cf->file_ent->ce_rev, path2, 0);
1.32 niallo 193: if (verbose == 1)
194: cvs_printf("Retrieving revision %s\n", r2);
1.33 ! joris 195: rcs_rev_write_stmp(cf->file_rcs, cf->file_rcsrev, path3, 0);
1.1 joris 196:
197: cvs_diffreg(path1, path3, d1);
198: cvs_diffreg(path2, path3, d2);
199:
1.28 xsa 200: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 201: cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 202: cvs_buf_free(d1);
203:
1.28 xsa 204: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 205: cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 206: cvs_buf_free(d2);
207:
208: argc = 0;
209: diffbuf = diffb;
210: argv[argc++] = dp13;
211: argv[argc++] = dp23;
212: argv[argc++] = path1;
213: argv[argc++] = path2;
214: argv[argc++] = path3;
1.7 joris 215:
1.33 ! joris 216: diff3_conflicts = diff3_internal(argc, argv, cf->file_path, r2);
! 217: if (diff3_conflicts < 0)
! 218: fatal("cvs_merge_file: merging failed for an unknown reason");
1.1 joris 219:
1.30 niallo 220: plen = cvs_buf_len(diffb);
1.1 joris 221: patch = cvs_buf_release(diffb);
1.30 niallo 222: dlen = cvs_buf_len(b1);
1.1 joris 223: data = cvs_buf_release(b1);
224:
1.33 ! joris 225: cvs_printf("Merging differences between %s and %s into `%s'\n",
! 226: r1, r2, cf->file_path);
! 227:
! 228: dlines = cvs_splitlines(data, dlen);
! 229: plines = cvs_splitlines(patch, plen);
! 230: ed_patch_lines(dlines, plines);
! 231: cvs_freelines(plines);
1.7 joris 232:
1.23 deraadt 233: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 234: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 235: "please correct.", diff3_conflicts,
1.11 reyk 236: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 237: }
1.1 joris 238:
1.33 ! joris 239: TAILQ_FOREACH(lp, &(dlines->l_lines), l_list) {
! 240: if (lp->l_line == NULL)
! 241: continue;
! 242:
! 243: if (write(cf->fd, lp->l_line, lp->l_len) == -1)
! 244: fatal("cvs_merge_file: %s", strerror(errno));
! 245: }
! 246:
! 247: cvs_freelines(dlines);
! 248:
! 249: if (data != NULL)
! 250: xfree(data);
1.8 joris 251: xfree(patch);
1.1 joris 252:
253: (void)unlink(path1);
254: (void)unlink(path2);
255: (void)unlink(path3);
256: (void)unlink(dp13);
257: (void)unlink(dp23);
1.28 xsa 258:
1.33 ! joris 259: xfree(path1);
! 260: xfree(path2);
! 261: xfree(path3);
! 262: xfree(dp13);
! 263: xfree(dp23);
1.1 joris 264: }
265:
266: static int
267: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
268: {
1.20 ray 269: size_t m, n;
270: int i;
1.1 joris 271:
272: /* XXX */
273: eflag = 3;
274: oflag = 1;
275:
276: if (argc < 5)
277: return (-1);
278:
1.29 xsa 279: i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
280: if (i < 0 ||i >= (int)sizeof(f1mark))
281: fatal("diff3_internal: truncation");
282:
283: i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
284: if (i < 0 ||i >= (int)sizeof(f3mark))
285: fatal("diff3_internal: truncation");
1.1 joris 286:
287: increase();
288: m = readin(argv[0], &d13);
289: n = readin(argv[1], &d23);
290:
291: for (i = 0; i <= 2; i++) {
292: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
1.24 joris 293: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 294: return (-1);
295: }
296: }
297:
298: return (merge(m, n));
299: }
300:
301: int
302: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
303: {
304: char op, *ep;
1.29 xsa 305: struct cvs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.19 xsa 306: int start, end, i, lineno;
1.30 niallo 307: u_char tmp;
1.1 joris 308:
309: dlp = TAILQ_FIRST(&(dlines->l_lines));
310: lp = TAILQ_FIRST(&(plines->l_lines));
311:
1.19 xsa 312: end = 0;
1.1 joris 313: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
314: lp = TAILQ_NEXT(lp, l_list)) {
1.30 niallo 315: /* Skip blank lines */
316: if (lp->l_len < 2)
317: continue;
318: /* NUL-terminate line buffer for strtol() safety. */
319: tmp = lp->l_line[lp->l_len - 1];
320: lp->l_line[lp->l_len - 1] = '\0';
321: /* len - 1 is NUL terminator so we use len - 2 for 'op' */
1.1 joris 322: op = lp->l_line[strlen(lp->l_line) - 1];
323: start = (int)strtol(lp->l_line, &ep, 10);
1.30 niallo 324: /* Restore the last byte of the buffer */
325: lp->l_line[lp->l_len - 1] = tmp;
1.1 joris 326: if (op == 'a') {
1.23 deraadt 327: if (start > dlines->l_nblines ||
328: start < 0 || *ep != 'a')
1.15 niallo 329: fatal("ed_patch_lines");
1.1 joris 330: } else if (op == 'c') {
1.23 deraadt 331: if (start > dlines->l_nblines ||
332: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 333: fatal("ed_patch_lines");
1.1 joris 334:
1.2 joris 335: if (*ep == ',') {
336: ep++;
337: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 338: if (end < 0 || *ep != 'c')
1.15 niallo 339: fatal("ed_patch_lines");
1.2 joris 340: } else {
341: end = start;
342: }
1.1 joris 343: }
344:
1.2 joris 345:
1.1 joris 346: for (;;) {
347: if (dlp == NULL)
348: break;
349: if (dlp->l_lineno == start)
350: break;
351: if (dlp->l_lineno > start) {
352: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
353: } else if (dlp->l_lineno < start) {
354: ndlp = TAILQ_NEXT(dlp, l_list);
355: if (ndlp->l_lineno > start)
356: break;
357: dlp = ndlp;
358: }
359: }
360:
361: if (dlp == NULL)
1.15 niallo 362: fatal("ed_patch_lines");
1.1 joris 363:
1.2 joris 364:
1.1 joris 365: if (op == 'c') {
1.29 xsa 366: insert_after = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.2 joris 367: for (i = 0; i <= (end - start); i++) {
1.1 joris 368: ndlp = TAILQ_NEXT(dlp, l_list);
369: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
370: dlp = ndlp;
371: }
1.29 xsa 372: dlp = insert_after;
1.1 joris 373: }
374:
375: if (op == 'a' || op == 'c') {
376: for (;;) {
377: ndlp = lp;
378: lp = TAILQ_NEXT(lp, l_list);
379: if (lp == NULL)
1.15 niallo 380: fatal("ed_patch_lines");
1.1 joris 381:
1.30 niallo 382: if (!memcmp(lp->l_line, ".", 1))
1.1 joris 383: break;
384:
385: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
386: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
387: lp, l_list);
388: dlp = lp;
389:
390: lp->l_lineno = start;
391: lp = ndlp;
392: }
393: }
394:
395: /*
396: * always resort lines as the markers might be put at the
397: * same line as we first started editing.
398: */
399: lineno = 0;
400: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
401: sort->l_lineno = lineno++;
402: dlines->l_nblines = lineno - 1;
403: }
404:
405: return (0);
406: }
407:
408: /*
409: * Pick up the line numbers of all changes from one change file.
410: * (This puts the numbers in a vector, which is not strictly necessary,
411: * since the vector is processed in one sequential pass.
412: * The vector could be optimized out of existence)
413: */
1.20 ray 414: static size_t
1.1 joris 415: readin(char *name, struct diff **dd)
416: {
417: int a, b, c, d;
418: char kind, *p;
419: size_t i;
420:
421: fp[0] = fopen(name, "r");
422: for (i = 0; (p = getchange(fp[0])); i++) {
423: if (i >= szchanges - 1)
424: increase();
425: a = b = number(&p);
426: if (*p == ',') {
427: p++;
428: b = number(&p);
429: }
430: kind = *p++;
431: c = d = number(&p);
432: if (*p==',') {
433: p++;
434: d = number(&p);
435: }
436: if (kind == 'a')
437: a++;
438: if (kind == 'd')
439: c++;
440: b++;
441: d++;
442: (*dd)[i].old.from = a;
443: (*dd)[i].old.to = b;
444: (*dd)[i].new.from = c;
445: (*dd)[i].new.to = d;
446: }
447:
1.14 xsa 448: if (i) {
449: (*dd)[i].old.from = (*dd)[i-1].old.to;
450: (*dd)[i].new.from = (*dd)[i-1].new.to;
451: }
1.1 joris 452: (void)fclose(fp[0]);
453:
454: return (i);
455: }
456:
457: static int
458: number(char **lc)
459: {
460: int nn;
461:
462: nn = 0;
463: while (isdigit((unsigned char)(**lc)))
464: nn = nn*10 + *(*lc)++ - '0';
465:
466: return (nn);
467: }
468:
469: static char *
470: getchange(FILE *b)
471: {
472: char *line;
473:
474: while ((line = getline(b, NULL))) {
475: if (isdigit((unsigned char)line[0]))
476: return (line);
477: }
478:
479: return (NULL);
480: }
481:
482: static char *
483: getline(FILE *b, size_t *n)
484: {
485: char *cp;
486: size_t len;
487: static char *buf;
488: static size_t bufsize;
489:
490: if ((cp = fgetln(b, &len)) == NULL)
491: return (NULL);
492:
493: if (cp[len - 1] != '\n')
494: len++;
495: if (len + 1 > bufsize) {
1.22 ray 496: char *newbuf;
1.1 joris 497: do {
498: bufsize += 1024;
499: } while (len + 1 > bufsize);
1.22 ray 500: newbuf = xrealloc(buf, 1, bufsize);
501: buf = newbuf;
1.1 joris 502: }
503: memcpy(buf, cp, len - 1);
504: buf[len - 1] = '\n';
505: buf[len] = '\0';
506: if (n != NULL)
507: *n = len;
508:
509: return (buf);
510: }
511:
512: static int
1.20 ray 513: merge(size_t m1, size_t m2)
1.1 joris 514: {
515: struct diff *d1, *d2, *d3;
516: int dpl, j, t1, t2;
517:
518: d1 = d13;
519: d2 = d23;
520: j = 0;
521: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
522: if (debug) {
523: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 524: d1->old.from, d1->old.to,
525: d1->new.from, d1->new.to,
526: d2->old.from, d2->old.to,
527: d2->new.from, d2->new.to);
1.1 joris 528: }
529:
530: /* first file is different from others */
531: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
532: /* stuff peculiar to 1st file */
533: if (eflag==0) {
534: separate("1");
535: change(1, &d1->old, 0);
536: keep(2, &d1->new);
537: change(3, &d1->new, 0);
538: }
539: d1++;
540: continue;
541: }
542:
543: /* second file is different from others */
544: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
545: if (eflag==0) {
546: separate("2");
547: keep(1, &d2->new);
548: change(2, &d2->old, 0);
549: change(3, &d2->new, 0);
550: }
551: d2++;
552: continue;
553: }
554:
555: /*
556: * Merge overlapping changes in first file
557: * this happens after extension (see below).
558: */
559: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
560: d1[1].old.from = d1->old.from;
561: d1[1].new.from = d1->new.from;
562: d1++;
563: continue;
564: }
565:
566: /* merge overlapping changes in second */
567: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
568: d2[1].old.from = d2->old.from;
569: d2[1].new.from = d2->new.from;
570: d2++;
571: continue;
572: }
573: /* stuff peculiar to third file or different in all */
574: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
575: dpl = duplicate(&d1->old,&d2->old);
576: if (dpl == -1)
577: return (-1);
578:
579: /*
580: * dpl = 0 means all files differ
581: * dpl = 1 means files 1 and 2 identical
582: */
583: if (eflag==0) {
584: separate(dpl ? "3" : "");
585: change(1, &d1->old, dpl);
586: change(2, &d2->old, 0);
587: d3 = d1->old.to > d1->old.from ? d1 : d2;
588: change(3, &d3->new, 0);
589: } else
590: j = edit(d1, dpl, j);
591: d1++;
592: d2++;
593: continue;
594: }
595:
596: /*
597: * Overlapping changes from file 1 and 2; extend changes
598: * appropriately to make them coincide.
599: */
600: if (d1->new.from < d2->new.from) {
601: d2->old.from -= d2->new.from-d1->new.from;
602: d2->new.from = d1->new.from;
603: } else if (d2->new.from < d1->new.from) {
604: d1->old.from -= d1->new.from-d2->new.from;
605: d1->new.from = d2->new.from;
606: }
607: if (d1->new.to > d2->new.to) {
608: d2->old.to += d1->new.to - d2->new.to;
609: d2->new.to = d1->new.to;
610: } else if (d2->new.to > d1->new.to) {
611: d1->old.to += d2->new.to - d1->new.to;
612: d1->new.to = d2->new.to;
613: }
614: }
615:
616: return (edscript(j));
617: }
618:
619: static void
620: separate(const char *s)
621: {
622: diff_output("====%s\n", s);
623: }
624:
625: /*
626: * The range of lines rold.from thru rold.to in file i is to be changed.
627: * It is to be printed only if it does not duplicate something to be
628: * printed later.
629: */
630: static void
631: change(int i, struct range *rold, int fdup)
632: {
633: diff_output("%d:", i);
634: last[i] = rold->to;
635: prange(rold);
636: if (fdup || debug)
637: return;
638: i--;
639: (void)skip(i, rold->from, NULL);
640: (void)skip(i, rold->to, " ");
641: }
642:
643: /*
644: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
645: */
646: static void
647: prange(struct range *rold)
648: {
649: if (rold->to <= rold->from)
650: diff_output("%da\n", rold->from - 1);
651: else {
652: diff_output("%d", rold->from);
653: if (rold->to > rold->from+1)
654: diff_output(",%d", rold->to - 1);
655: diff_output("c\n");
656: }
657: }
658:
659: /*
660: * No difference was reported by diff between file 1 (or 2) and file 3,
661: * and an artificial dummy difference (trange) must be ginned up to
662: * correspond to the change reported in the other file.
663: */
664: static void
665: keep(int i, struct range *rnew)
666: {
667: int delta;
668: struct range trange;
669:
670: delta = last[3] - last[i];
671: trange.from = rnew->from - delta;
672: trange.to = rnew->to - delta;
673: change(i, &trange, 1);
674: }
675:
676: /*
677: * skip to just before line number from in file "i". If "pr" is non-NULL,
678: * print all skipped stuff with string pr as a prefix.
679: */
680: static int
681: skip(int i, int from, char *pr)
682: {
683: size_t j, n;
684: char *line;
685:
686: for (n = 0; cline[i] < from - 1; n += j) {
687: if ((line = getline(fp[i], &j)) == NULL)
688: return (-1);
689: if (pr != NULL)
690: diff_output("%s%s", pr, line);
691: cline[i]++;
692: }
693: return ((int) n);
694: }
695:
696: /*
697: * Return 1 or 0 according as the old range (in file 1) contains exactly
698: * the same data as the new range (in file 2).
699: */
700: static int
701: duplicate(struct range *r1, struct range *r2)
702: {
703: int c,d;
704: int nchar;
705: int nline;
706:
707: if (r1->to-r1->from != r2->to-r2->from)
708: return (0);
709: (void)skip(0, r1->from, NULL);
710: (void)skip(1, r2->from, NULL);
711: nchar = 0;
712: for (nline=0; nline < r1->to - r1->from; nline++) {
713: do {
714: c = getc(fp[0]);
715: d = getc(fp[1]);
716: if (c == -1 || d== -1)
717: return (-1);
718: nchar++;
719: if (c != d) {
720: repos(nchar);
721: return (0);
722: }
723: } while (c != '\n');
724: }
725: repos(nchar);
726: return (1);
727: }
728:
729: static void
730: repos(int nchar)
731: {
732: int i;
733:
734: for (i = 0; i < 2; i++)
735: (void)fseek(fp[i], (long)-nchar, 1);
736: }
737:
738: /*
739: * collect an editing script for later regurgitation
740: */
741: static int
742: edit(struct diff *diff, int fdup, int j)
743: {
744: if (((fdup + 1) & eflag) == 0)
745: return (j);
746: j++;
747: overlap[j] = !fdup;
748: if (!fdup)
749: overlapcnt++;
750: de[j].old.from = diff->old.from;
751: de[j].old.to = diff->old.to;
752: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
753: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
754: return (j);
755: }
756:
757: /* regurgitate */
758: static int
759: edscript(int n)
760: {
761: int j, k;
1.2 joris 762: char block[BUFSIZ+1];
1.1 joris 763:
764: for (n = n; n > 0; n--) {
765: if (!oflag || !overlap[n])
766: prange(&de[n].old);
767: else
768: diff_output("%da\n=======\n", de[n].old.to -1);
769: (void)fseek(fp[2], (long)de[n].new.from, 0);
770: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
771: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 772: if (fread(block, (size_t)1, (size_t)j,
773: fp[2]) != (size_t)j)
1.1 joris 774: return (-1);
775: block[j] = '\0';
776: diff_output("%s", block);
777: }
1.2 joris 778:
1.1 joris 779: if (!oflag || !overlap[n])
780: diff_output(".\n");
781: else {
782: diff_output("%s\n.\n", f3mark);
783: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
784: }
785: }
786:
787: return (overlapcnt);
788: }
789:
790: static void
791: increase(void)
792: {
793: struct diff *p;
794: char *q;
795: size_t newsz, incr;
796:
797: /* are the memset(3) calls needed? */
798: newsz = szchanges == 0 ? 64 : 2 * szchanges;
799: incr = newsz - szchanges;
800:
1.22 ray 801: p = xrealloc(d13, newsz, sizeof(*d13));
802: memset(p + szchanges, 0, incr * sizeof(*d13));
1.1 joris 803: d13 = p;
1.22 ray 804: p = xrealloc(d23, newsz, sizeof(*d23));
805: memset(p + szchanges, 0, incr * sizeof(*d23));
1.1 joris 806: d23 = p;
1.22 ray 807: p = xrealloc(de, newsz, sizeof(*de));
808: memset(p + szchanges, 0, incr * sizeof(*de));
1.1 joris 809: de = p;
1.22 ray 810: q = xrealloc(overlap, newsz, sizeof(*overlap));
811: memset(q + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 812: overlap = q;
813: szchanges = newsz;
814: }
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