Annotation of src/usr.bin/cvs/diff3.c, Revision 1.8
1.8 ! joris 1: /* $OpenBSD: diff3.c,v 1.7 2005/12/03 01:02:08 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
1.8 ! joris 74: static const char rcsid[] = "$OpenBSD: diff3.c,v 1.7 2005/12/03 01:02:08 joris Exp $";
1.1 joris 75: #endif /* not lint */
76:
77: #include <sys/queue.h>
78:
79: #include <err.h>
80: #include <ctype.h>
81: #include <stdio.h>
82: #include <stdlib.h>
83: #include <string.h>
84: #include <unistd.h>
85:
86: #include "cvs.h"
87: #include "log.h"
88: #include "diff.h"
89:
90: /* diff3 - 3-way differential file comparison */
91:
92: /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
93: *
94: * d13 = diff report on f1 vs f3
95: * d23 = diff report on f2 vs f3
96: * f1, f2, f3 the 3 files
97: * if changes in f1 overlap with changes in f3, m1 and m3 are used
98: * to mark the overlaps; otherwise, the file names f1 and f3 are used
99: * (only for options E and X).
100: */
101:
102: /*
103: * "from" is first in range of changed lines; "to" is last+1
104: * from=to=line after point of insertion for added lines.
105: */
106: struct range {
107: int from;
108: int to;
109: };
110:
111: struct diff {
112: struct range old;
113: struct range new;
114: };
115:
116: static size_t szchanges;
117:
118: static struct diff *d13;
119: static struct diff *d23;
120:
121: /*
122: * "de" is used to gather editing scripts. These are later spewed out in
123: * reverse order. Its first element must be all zero, the "new" component
124: * of "de" contains line positions or byte positions depending on when you
125: * look (!?). Array overlap indicates which sections in "de" correspond to
126: * lines that are different in all three files.
127: */
128: static struct diff *de;
129: static char *overlap;
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;
142: static char f1mark[40], f3mark[40]; /* markers for -E and -X */
143:
144: static int duplicate(struct range *, struct range *);
145: static int edit(struct diff *, int, int);
146: static char *getchange(FILE *);
147: static char *getline(FILE *, size_t *);
148: static int number(char **);
149: static int readin(char *, struct diff **);
150: static int skip(int, int, char *);
151: static int edscript(int);
152: static int merge(int, int);
153: static void change(int, struct range *, int);
154: static void keep(int, struct range *);
155: static void prange(struct range *);
156: static void repos(int);
157: static void separate(const char *);
158: static void increase(void);
159: static int diff3_internal(int, char **, const char *, const char *);
160:
1.5 xsa 161: int diff3_conflicts = 0;
1.4 joris 162:
1.1 joris 163: BUF *
164: cvs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2)
165: {
166: int ret, argc;
167: char *data, *patch;
168: char *argv[5], r1[16], r2[16];
169: char path1[MAXPATHLEN], path2[MAXPATHLEN], path3[MAXPATHLEN];
170: char dp13[MAXPATHLEN], dp23[MAXPATHLEN];
171: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
172:
173: ret = -1;
174: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
175:
176: rcsnum_tostr(rev1, r1, sizeof(r1));
177: rcsnum_tostr(rev2, r2, sizeof(r2));
178:
179: if ((b1 = cvs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
180: goto out;
181:
1.4 joris 182: cvs_printf("Retrieving revision %s\n", r1);
1.1 joris 183: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
184: goto out;
185:
1.4 joris 186: cvs_printf("Retrieving revision %s\n", r2);
1.1 joris 187: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
188: goto out;
189:
1.6 xsa 190: if ((d1 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT)) == NULL)
1.1 joris 191: goto out;
192:
1.6 xsa 193: if ((d2 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT)) == NULL)
1.1 joris 194: goto out;
195:
1.6 xsa 196: if ((diffb = cvs_buf_alloc((size_t)128, BUF_AUTOEXT)) == NULL)
1.1 joris 197: goto out;
198:
199: strlcpy(path1, "/tmp/diff1.XXXXXXXXXX", sizeof(path1));
200: if (cvs_buf_write_stmp(b1, path1, 0600) == -1)
201: goto out;
202:
203: strlcpy(path2, "/tmp/diff2.XXXXXXXXXX", sizeof(path2));
204: if (cvs_buf_write_stmp(b2, path2, 0600) == -1)
205: goto out;
206:
207: strlcpy(path3, "/tmp/diff3.XXXXXXXXXX", sizeof(path3));
208: if (cvs_buf_write_stmp(b3, path3, 0600) == -1)
209: goto out;
210:
211: cvs_buf_free(b2);
212: b2 = NULL;
213:
214: cvs_diffreg(path1, path3, d1);
215: cvs_diffreg(path2, path3, d2);
216:
217: strlcpy(dp13, "/tmp/d13.XXXXXXXXXX", sizeof(dp13));
218: if (cvs_buf_write_stmp(d1, dp13, 0600) < 0)
219: goto out;
220:
221: cvs_buf_free(d1);
222: d1 = NULL;
223:
224: strlcpy(dp23, "/tmp/d23.XXXXXXXXXX", sizeof(dp23));
225: if (cvs_buf_write_stmp(d2, dp23, 0600) < 0)
226: goto out;
227:
228: cvs_buf_free(d2);
229: d2 = NULL;
230:
231: argc = 0;
232: diffbuf = diffb;
233: argv[argc++] = dp13;
234: argv[argc++] = dp23;
235: argv[argc++] = path1;
236: argv[argc++] = path2;
237: argv[argc++] = path3;
1.7 joris 238:
239: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
240: if (diff3_conflicts < 0) {
241: cvs_buf_free(diffb);
242: diffb = NULL;
1.1 joris 243: goto out;
1.7 joris 244: }
1.1 joris 245:
246: if (cvs_buf_putc(diffb, '\0') < 0) {
247: cvs_buf_free(diffb);
1.7 joris 248: diffb = NULL;
1.1 joris 249: goto out;
250: }
251:
252: if (cvs_buf_putc(b1, '\0') < 0) {
253: cvs_buf_free(diffb);
1.7 joris 254: diffb = NULL;
1.1 joris 255: goto out;
256: }
257:
258: patch = cvs_buf_release(diffb);
259: data = cvs_buf_release(b1);
260: diffb = b1 = NULL;
1.4 joris 261:
262: cvs_printf("Merging changes between '%s' and '%s' ", r1, r2);
263: cvs_printf("into '%s'\n", workfile);
1.1 joris 264:
265: if ((diffb = cvs_patchfile(data, patch, ed_patch_lines)) == NULL)
266: goto out;
1.7 joris 267:
268: if (diff3_conflicts != 0) {
269: cvs_printf("%d conflict%s found during merge, please correct.\n",
270: diff3_conflicts, (diff3_conflicts > 1) ? "s" : "");
271: }
1.1 joris 272:
1.8 ! joris 273: xfree(data);
! 274: xfree(patch);
1.1 joris 275:
276: out:
277: if (b1 != NULL)
278: cvs_buf_free(b1);
279: if (b2 != NULL)
280: cvs_buf_free(b2);
281: if (b3 != NULL)
282: cvs_buf_free(b3);
283: if (d1 != NULL)
284: cvs_buf_free(d1);
285: if (d2 != NULL)
286: cvs_buf_free(d2);
287:
288: (void)unlink(path1);
289: (void)unlink(path2);
290: (void)unlink(path3);
291: (void)unlink(dp13);
292: (void)unlink(dp23);
293:
294: return (diffb);
295: }
296:
297: static int
298: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
299: {
300: int i, m, n;
301:
302: /* XXX */
303: eflag = 3;
304: oflag = 1;
305:
306: if (argc < 5)
307: return (-1);
308:
309: snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
310: snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
311:
312: increase();
313: m = readin(argv[0], &d13);
314: n = readin(argv[1], &d23);
315:
316: for (i = 0; i <= 2; i++) {
317: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
318: cvs_log(LP_ERRNO, "%s", argv[i + 2]);
319: return (-1);
320: }
321: }
322:
323: return (merge(m, n));
324: }
325:
326: int
327: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
328: {
329: char op, *ep;
330: struct cvs_line *sort, *lp, *dlp, *ndlp;
331: int start, end, busy, i, lineno;
332:
333: dlp = TAILQ_FIRST(&(dlines->l_lines));
334: lp = TAILQ_FIRST(&(plines->l_lines));
335:
1.3 joris 336: busy = end = 0;
1.1 joris 337: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
338: lp = TAILQ_NEXT(lp, l_list)) {
339: op = lp->l_line[strlen(lp->l_line) - 1];
340: start = (int)strtol(lp->l_line, &ep, 10);
341: if (op == 'a') {
342: if ((start > dlines->l_nblines) ||
343: (start < 0) || (*ep != 'a'))
344: return (-1);
345: } else if (op == 'c') {
346: if ((start > dlines->l_nblines) ||
1.2 joris 347: (start < 0) || ((*ep != ',') && (*ep != 'c')))
1.1 joris 348: return (-1);
349:
1.2 joris 350: if (*ep == ',') {
351: ep++;
352: end = (int)strtol(ep, &ep, 10);
353: if ((end < 0) || (*ep != 'c'))
354: return (-1);
355: } else {
356: end = start;
357: }
1.1 joris 358: }
359:
1.2 joris 360:
1.1 joris 361: for (;;) {
362: if (dlp == NULL)
363: break;
364: if (dlp->l_lineno == start)
365: break;
366: if (dlp->l_lineno > start) {
367: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
368: } else if (dlp->l_lineno < start) {
369: ndlp = TAILQ_NEXT(dlp, l_list);
370: if (ndlp->l_lineno > start)
371: break;
372: dlp = ndlp;
373: }
374: }
375:
376: if (dlp == NULL)
377: return (-1);
378:
1.2 joris 379:
1.1 joris 380: if (op == 'c') {
1.2 joris 381: for (i = 0; i <= (end - start); i++) {
1.1 joris 382: ndlp = TAILQ_NEXT(dlp, l_list);
383: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
384: dlp = ndlp;
385: }
1.2 joris 386: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.1 joris 387: }
388:
389: if (op == 'a' || op == 'c') {
390: for (;;) {
391: ndlp = lp;
392: lp = TAILQ_NEXT(lp, l_list);
393: if (lp == NULL)
394: return (-1);
395:
396: if (!strcmp(lp->l_line, "."))
397: break;
398:
399: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
400: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
401: lp, l_list);
402: dlp = lp;
403:
404: lp->l_lineno = start;
405: lp = ndlp;
406: }
407: }
408:
409: /*
410: * always resort lines as the markers might be put at the
411: * same line as we first started editing.
412: */
413: lineno = 0;
414: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
415: sort->l_lineno = lineno++;
416: dlines->l_nblines = lineno - 1;
417: }
418:
419: return (0);
420: }
421:
422: /*
423: * Pick up the line numbers of all changes from one change file.
424: * (This puts the numbers in a vector, which is not strictly necessary,
425: * since the vector is processed in one sequential pass.
426: * The vector could be optimized out of existence)
427: */
428: static int
429: readin(char *name, struct diff **dd)
430: {
431: int a, b, c, d;
432: char kind, *p;
433: size_t i;
434:
435: fp[0] = fopen(name, "r");
436: for (i = 0; (p = getchange(fp[0])); i++) {
437: if (i >= szchanges - 1)
438: increase();
439: a = b = number(&p);
440: if (*p == ',') {
441: p++;
442: b = number(&p);
443: }
444: kind = *p++;
445: c = d = number(&p);
446: if (*p==',') {
447: p++;
448: d = number(&p);
449: }
450: if (kind == 'a')
451: a++;
452: if (kind == 'd')
453: c++;
454: b++;
455: d++;
456: (*dd)[i].old.from = a;
457: (*dd)[i].old.to = b;
458: (*dd)[i].new.from = c;
459: (*dd)[i].new.to = d;
460: }
461:
462: (*dd)[i].old.from = (*dd)[i-1].old.to;
463: (*dd)[i].new.from = (*dd)[i-1].new.to;
464: (void)fclose(fp[0]);
465:
466: return (i);
467: }
468:
469: static int
470: number(char **lc)
471: {
472: int nn;
473:
474: nn = 0;
475: while (isdigit((unsigned char)(**lc)))
476: nn = nn*10 + *(*lc)++ - '0';
477:
478: return (nn);
479: }
480:
481: static char *
482: getchange(FILE *b)
483: {
484: char *line;
485:
486: while ((line = getline(b, NULL))) {
487: if (isdigit((unsigned char)line[0]))
488: return (line);
489: }
490:
491: return (NULL);
492: }
493:
494: static char *
495: getline(FILE *b, size_t *n)
496: {
497: char *cp;
498: size_t len;
499: static char *buf;
500: static size_t bufsize;
501:
502: if ((cp = fgetln(b, &len)) == NULL)
503: return (NULL);
504:
505: if (cp[len - 1] != '\n')
506: len++;
507: if (len + 1 > bufsize) {
508: do {
509: bufsize += 1024;
510: } while (len + 1 > bufsize);
1.8 ! joris 511: buf = xrealloc(buf, bufsize);
1.1 joris 512: }
513: memcpy(buf, cp, len - 1);
514: buf[len - 1] = '\n';
515: buf[len] = '\0';
516: if (n != NULL)
517: *n = len;
518:
519: return (buf);
520: }
521:
522: static int
523: merge(int m1, int m2)
524: {
525: struct diff *d1, *d2, *d3;
526: int dpl, j, t1, t2;
527:
528: d1 = d13;
529: d2 = d23;
530: j = 0;
531: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
532: if (debug) {
533: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
534: d1->old.from,d1->old.to,
535: d1->new.from,d1->new.to,
536: d2->old.from,d2->old.to,
537: d2->new.from,d2->new.to);
538: }
539:
540: /* first file is different from others */
541: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
542: /* stuff peculiar to 1st file */
543: if (eflag==0) {
544: separate("1");
545: change(1, &d1->old, 0);
546: keep(2, &d1->new);
547: change(3, &d1->new, 0);
548: }
549: d1++;
550: continue;
551: }
552:
553: /* second file is different from others */
554: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
555: if (eflag==0) {
556: separate("2");
557: keep(1, &d2->new);
558: change(2, &d2->old, 0);
559: change(3, &d2->new, 0);
560: }
561: d2++;
562: continue;
563: }
564:
565: /*
566: * Merge overlapping changes in first file
567: * this happens after extension (see below).
568: */
569: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
570: d1[1].old.from = d1->old.from;
571: d1[1].new.from = d1->new.from;
572: d1++;
573: continue;
574: }
575:
576: /* merge overlapping changes in second */
577: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
578: d2[1].old.from = d2->old.from;
579: d2[1].new.from = d2->new.from;
580: d2++;
581: continue;
582: }
583: /* stuff peculiar to third file or different in all */
584: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
585: dpl = duplicate(&d1->old,&d2->old);
586: if (dpl == -1)
587: return (-1);
588:
589: /*
590: * dpl = 0 means all files differ
591: * dpl = 1 means files 1 and 2 identical
592: */
593: if (eflag==0) {
594: separate(dpl ? "3" : "");
595: change(1, &d1->old, dpl);
596: change(2, &d2->old, 0);
597: d3 = d1->old.to > d1->old.from ? d1 : d2;
598: change(3, &d3->new, 0);
599: } else
600: j = edit(d1, dpl, j);
601: d1++;
602: d2++;
603: continue;
604: }
605:
606: /*
607: * Overlapping changes from file 1 and 2; extend changes
608: * appropriately to make them coincide.
609: */
610: if (d1->new.from < d2->new.from) {
611: d2->old.from -= d2->new.from-d1->new.from;
612: d2->new.from = d1->new.from;
613: } else if (d2->new.from < d1->new.from) {
614: d1->old.from -= d1->new.from-d2->new.from;
615: d1->new.from = d2->new.from;
616: }
617: if (d1->new.to > d2->new.to) {
618: d2->old.to += d1->new.to - d2->new.to;
619: d2->new.to = d1->new.to;
620: } else if (d2->new.to > d1->new.to) {
621: d1->old.to += d2->new.to - d1->new.to;
622: d1->new.to = d2->new.to;
623: }
624: }
625:
626: return (edscript(j));
627: }
628:
629: static void
630: separate(const char *s)
631: {
632: diff_output("====%s\n", s);
633: }
634:
635: /*
636: * The range of lines rold.from thru rold.to in file i is to be changed.
637: * It is to be printed only if it does not duplicate something to be
638: * printed later.
639: */
640: static void
641: change(int i, struct range *rold, int fdup)
642: {
643: diff_output("%d:", i);
644: last[i] = rold->to;
645: prange(rold);
646: if (fdup || debug)
647: return;
648: i--;
649: (void)skip(i, rold->from, NULL);
650: (void)skip(i, rold->to, " ");
651: }
652:
653: /*
654: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
655: */
656: static void
657: prange(struct range *rold)
658: {
659: if (rold->to <= rold->from)
660: diff_output("%da\n", rold->from - 1);
661: else {
662: diff_output("%d", rold->from);
663: if (rold->to > rold->from+1)
664: diff_output(",%d", rold->to - 1);
665: diff_output("c\n");
666: }
667: }
668:
669: /*
670: * No difference was reported by diff between file 1 (or 2) and file 3,
671: * and an artificial dummy difference (trange) must be ginned up to
672: * correspond to the change reported in the other file.
673: */
674: static void
675: keep(int i, struct range *rnew)
676: {
677: int delta;
678: struct range trange;
679:
680: delta = last[3] - last[i];
681: trange.from = rnew->from - delta;
682: trange.to = rnew->to - delta;
683: change(i, &trange, 1);
684: }
685:
686: /*
687: * skip to just before line number from in file "i". If "pr" is non-NULL,
688: * print all skipped stuff with string pr as a prefix.
689: */
690: static int
691: skip(int i, int from, char *pr)
692: {
693: size_t j, n;
694: char *line;
695:
696: for (n = 0; cline[i] < from - 1; n += j) {
697: if ((line = getline(fp[i], &j)) == NULL)
698: return (-1);
699: if (pr != NULL)
700: diff_output("%s%s", pr, line);
701: cline[i]++;
702: }
703: return ((int) n);
704: }
705:
706: /*
707: * Return 1 or 0 according as the old range (in file 1) contains exactly
708: * the same data as the new range (in file 2).
709: */
710: static int
711: duplicate(struct range *r1, struct range *r2)
712: {
713: int c,d;
714: int nchar;
715: int nline;
716:
717: if (r1->to-r1->from != r2->to-r2->from)
718: return (0);
719: (void)skip(0, r1->from, NULL);
720: (void)skip(1, r2->from, NULL);
721: nchar = 0;
722: for (nline=0; nline < r1->to - r1->from; nline++) {
723: do {
724: c = getc(fp[0]);
725: d = getc(fp[1]);
726: if (c == -1 || d== -1)
727: return (-1);
728: nchar++;
729: if (c != d) {
730: repos(nchar);
731: return (0);
732: }
733: } while (c != '\n');
734: }
735: repos(nchar);
736: return (1);
737: }
738:
739: static void
740: repos(int nchar)
741: {
742: int i;
743:
744: for (i = 0; i < 2; i++)
745: (void)fseek(fp[i], (long)-nchar, 1);
746: }
747:
748: /*
749: * collect an editing script for later regurgitation
750: */
751: static int
752: edit(struct diff *diff, int fdup, int j)
753: {
754: if (((fdup + 1) & eflag) == 0)
755: return (j);
756: j++;
757: overlap[j] = !fdup;
758: if (!fdup)
759: overlapcnt++;
760: de[j].old.from = diff->old.from;
761: de[j].old.to = diff->old.to;
762: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
763: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
764: return (j);
765: }
766:
767: /* regurgitate */
768: static int
769: edscript(int n)
770: {
771: int j, k;
1.2 joris 772: char block[BUFSIZ+1];
1.1 joris 773:
774: for (n = n; n > 0; n--) {
775: if (!oflag || !overlap[n])
776: prange(&de[n].old);
777: else
778: diff_output("%da\n=======\n", de[n].old.to -1);
779: (void)fseek(fp[2], (long)de[n].new.from, 0);
780: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
781: j = k > BUFSIZ ? BUFSIZ : k;
1.6 xsa 782: if (fread(block, (size_t)1, (size_t)j, fp[2]) != (size_t)j)
1.1 joris 783: return (-1);
784: block[j] = '\0';
785: diff_output("%s", block);
786: }
1.2 joris 787:
1.1 joris 788: if (!oflag || !overlap[n])
789: diff_output(".\n");
790: else {
791: diff_output("%s\n.\n", f3mark);
792: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
793: }
794: }
795:
796: return (overlapcnt);
797: }
798:
799: static void
800: increase(void)
801: {
802: struct diff *p;
803: char *q;
804: size_t newsz, incr;
805:
806: /* are the memset(3) calls needed? */
807: newsz = szchanges == 0 ? 64 : 2 * szchanges;
808: incr = newsz - szchanges;
809:
1.8 ! joris 810: p = xrealloc(d13, newsz * sizeof(struct diff));
1.1 joris 811: memset(p + szchanges, 0, incr * sizeof(struct diff));
812: d13 = p;
1.8 ! joris 813: p = xrealloc(d23, newsz * sizeof(struct diff));
1.1 joris 814: memset(p + szchanges, 0, incr * sizeof(struct diff));
815: d23 = p;
1.8 ! joris 816: p = xrealloc(de, newsz * sizeof(struct diff));
1.1 joris 817: memset(p + szchanges, 0, incr * sizeof(struct diff));
818: de = p;
1.8 ! joris 819: q = xrealloc(overlap, newsz * sizeof(char));
1.1 joris 820: memset(q + szchanges, 0, incr * sizeof(char));
821: overlap = q;
822: szchanges = newsz;
823: }
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