Annotation of src/usr.bin/cvs/diff3.c, Revision 1.27
1.27 ! ray 1: /* $OpenBSD: diff3.c,v 1.26 2006/07/08 09:25:44 ray 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[] =
1.27 ! ray 75: "$OpenBSD: diff3.c,v 1.26 2006/07/08 09:25:44 ray 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;
136: static char f1mark[40], f3mark[40]; /* markers for -E and -X */
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:
1.1 joris 157: BUF *
1.25 joris 158: cvs_diff3(RCSFILE *rf, char *workfile, int workfd, RCSNUM *rev1,
159: RCSNUM *rev2, int verbose)
1.1 joris 160: {
1.19 xsa 161: int argc;
1.1 joris 162: char *data, *patch;
163: char *argv[5], r1[16], r2[16];
164: char path1[MAXPATHLEN], path2[MAXPATHLEN], path3[MAXPATHLEN];
165: char dp13[MAXPATHLEN], dp23[MAXPATHLEN];
166: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
167:
168: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
169:
170: rcsnum_tostr(rev1, r1, sizeof(r1));
171: rcsnum_tostr(rev2, r2, sizeof(r2));
172:
1.25 joris 173: if ((b1 = cvs_buf_load_fd(workfd, BUF_AUTOEXT)) == NULL)
1.1 joris 174: goto out;
175:
1.18 xsa 176: if (verbose == 1)
177: cvs_printf("Retrieving revision %s\n", r1);
1.1 joris 178: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
179: goto out;
180:
1.18 xsa 181: if (verbose == 1)
182: cvs_printf("Retrieving revision %s\n", r2);
1.1 joris 183: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
184: goto out;
185:
1.10 joris 186: d1 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
187: d2 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
188: diffb = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
1.1 joris 189:
190: strlcpy(path1, "/tmp/diff1.XXXXXXXXXX", sizeof(path1));
1.26 ray 191: cvs_buf_write_stmp(b1, path1, NULL);
1.1 joris 192:
193: strlcpy(path2, "/tmp/diff2.XXXXXXXXXX", sizeof(path2));
1.26 ray 194: cvs_buf_write_stmp(b2, path2, NULL);
1.1 joris 195:
196: strlcpy(path3, "/tmp/diff3.XXXXXXXXXX", sizeof(path3));
1.26 ray 197: cvs_buf_write_stmp(b3, path3, NULL);
1.1 joris 198:
199: cvs_buf_free(b2);
200: b2 = NULL;
201:
202: cvs_diffreg(path1, path3, d1);
203: cvs_diffreg(path2, path3, d2);
204:
205: strlcpy(dp13, "/tmp/d13.XXXXXXXXXX", sizeof(dp13));
1.26 ray 206: cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 207:
208: cvs_buf_free(d1);
209: d1 = NULL;
210:
211: strlcpy(dp23, "/tmp/d23.XXXXXXXXXX", sizeof(dp23));
1.26 ray 212: cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 213:
214: cvs_buf_free(d2);
215: d2 = NULL;
216:
217: argc = 0;
218: diffbuf = diffb;
219: argv[argc++] = dp13;
220: argv[argc++] = dp23;
221: argv[argc++] = path1;
222: argv[argc++] = path2;
223: argv[argc++] = path3;
1.7 joris 224:
225: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
226: if (diff3_conflicts < 0) {
227: cvs_buf_free(diffb);
228: diffb = NULL;
1.1 joris 229: goto out;
1.7 joris 230: }
1.1 joris 231:
1.9 xsa 232: cvs_buf_putc(diffb, '\0');
233: cvs_buf_putc(b1, '\0');
1.1 joris 234:
235: patch = cvs_buf_release(diffb);
236: data = cvs_buf_release(b1);
237: diffb = b1 = NULL;
238:
239: if ((diffb = cvs_patchfile(data, patch, ed_patch_lines)) == NULL)
240: goto out;
1.7 joris 241:
1.23 deraadt 242: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 243: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 244: "please correct.", diff3_conflicts,
1.11 reyk 245: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 246: }
1.1 joris 247:
1.8 joris 248: xfree(data);
249: xfree(patch);
1.1 joris 250:
251: out:
252: if (b1 != NULL)
253: cvs_buf_free(b1);
254: if (b2 != NULL)
255: cvs_buf_free(b2);
256: if (b3 != NULL)
257: cvs_buf_free(b3);
258: if (d1 != NULL)
259: cvs_buf_free(d1);
260: if (d2 != NULL)
261: cvs_buf_free(d2);
262:
263: (void)unlink(path1);
264: (void)unlink(path2);
265: (void)unlink(path3);
266: (void)unlink(dp13);
267: (void)unlink(dp23);
268:
269: return (diffb);
270: }
271:
272: static int
273: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
274: {
1.20 ray 275: size_t m, n;
276: int i;
1.1 joris 277:
278: /* XXX */
279: eflag = 3;
280: oflag = 1;
281:
282: if (argc < 5)
283: return (-1);
284:
1.13 xsa 285: strlcpy(f1mark, "<<<<<<< ", sizeof(f1mark));
286: strlcat(f1mark, fmark, sizeof(f1mark));
287:
288: strlcpy(f3mark, ">>>>>>> ", sizeof(f3mark));
289: strlcat(f3mark, rmark, sizeof(f3mark));
1.1 joris 290:
291: increase();
292: m = readin(argv[0], &d13);
293: n = readin(argv[1], &d23);
294:
295: for (i = 0; i <= 2; i++) {
296: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
1.24 joris 297: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 298: return (-1);
299: }
300: }
301:
302: return (merge(m, n));
303: }
304:
305: int
306: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
307: {
308: char op, *ep;
309: struct cvs_line *sort, *lp, *dlp, *ndlp;
1.19 xsa 310: int start, end, i, lineno;
1.1 joris 311:
312: dlp = TAILQ_FIRST(&(dlines->l_lines));
313: lp = TAILQ_FIRST(&(plines->l_lines));
314:
1.19 xsa 315: end = 0;
1.1 joris 316: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
317: lp = TAILQ_NEXT(lp, l_list)) {
1.27 ! ray 318: if (lp->l_line[0] == '\0')
! 319: fatal("ed_patch_lines");
1.1 joris 320: op = lp->l_line[strlen(lp->l_line) - 1];
321: start = (int)strtol(lp->l_line, &ep, 10);
322: if (op == 'a') {
1.23 deraadt 323: if (start > dlines->l_nblines ||
324: start < 0 || *ep != 'a')
1.15 niallo 325: fatal("ed_patch_lines");
1.1 joris 326: } else if (op == 'c') {
1.23 deraadt 327: if (start > dlines->l_nblines ||
328: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 329: fatal("ed_patch_lines");
1.1 joris 330:
1.2 joris 331: if (*ep == ',') {
332: ep++;
333: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 334: if (end < 0 || *ep != 'c')
1.15 niallo 335: fatal("ed_patch_lines");
1.2 joris 336: } else {
337: end = start;
338: }
1.1 joris 339: }
340:
1.2 joris 341:
1.1 joris 342: for (;;) {
343: if (dlp == NULL)
344: break;
345: if (dlp->l_lineno == start)
346: break;
347: if (dlp->l_lineno > start) {
348: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
349: } else if (dlp->l_lineno < start) {
350: ndlp = TAILQ_NEXT(dlp, l_list);
351: if (ndlp->l_lineno > start)
352: break;
353: dlp = ndlp;
354: }
355: }
356:
357: if (dlp == NULL)
1.15 niallo 358: fatal("ed_patch_lines");
1.1 joris 359:
1.2 joris 360:
1.1 joris 361: if (op == 'c') {
1.2 joris 362: for (i = 0; i <= (end - start); i++) {
1.1 joris 363: ndlp = TAILQ_NEXT(dlp, l_list);
364: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
365: dlp = ndlp;
366: }
1.2 joris 367: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.1 joris 368: }
369:
370: if (op == 'a' || op == 'c') {
371: for (;;) {
372: ndlp = lp;
373: lp = TAILQ_NEXT(lp, l_list);
374: if (lp == NULL)
1.15 niallo 375: fatal("ed_patch_lines");
1.1 joris 376:
377: if (!strcmp(lp->l_line, "."))
378: break;
379:
380: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
381: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
382: lp, l_list);
383: dlp = lp;
384:
385: lp->l_lineno = start;
386: lp = ndlp;
387: }
388: }
389:
390: /*
391: * always resort lines as the markers might be put at the
392: * same line as we first started editing.
393: */
394: lineno = 0;
395: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
396: sort->l_lineno = lineno++;
397: dlines->l_nblines = lineno - 1;
398: }
399:
400: return (0);
401: }
402:
403: /*
404: * Pick up the line numbers of all changes from one change file.
405: * (This puts the numbers in a vector, which is not strictly necessary,
406: * since the vector is processed in one sequential pass.
407: * The vector could be optimized out of existence)
408: */
1.20 ray 409: static size_t
1.1 joris 410: readin(char *name, struct diff **dd)
411: {
412: int a, b, c, d;
413: char kind, *p;
414: size_t i;
415:
416: fp[0] = fopen(name, "r");
417: for (i = 0; (p = getchange(fp[0])); i++) {
418: if (i >= szchanges - 1)
419: increase();
420: a = b = number(&p);
421: if (*p == ',') {
422: p++;
423: b = number(&p);
424: }
425: kind = *p++;
426: c = d = number(&p);
427: if (*p==',') {
428: p++;
429: d = number(&p);
430: }
431: if (kind == 'a')
432: a++;
433: if (kind == 'd')
434: c++;
435: b++;
436: d++;
437: (*dd)[i].old.from = a;
438: (*dd)[i].old.to = b;
439: (*dd)[i].new.from = c;
440: (*dd)[i].new.to = d;
441: }
442:
1.14 xsa 443: if (i) {
444: (*dd)[i].old.from = (*dd)[i-1].old.to;
445: (*dd)[i].new.from = (*dd)[i-1].new.to;
446: }
1.1 joris 447: (void)fclose(fp[0]);
448:
449: return (i);
450: }
451:
452: static int
453: number(char **lc)
454: {
455: int nn;
456:
457: nn = 0;
458: while (isdigit((unsigned char)(**lc)))
459: nn = nn*10 + *(*lc)++ - '0';
460:
461: return (nn);
462: }
463:
464: static char *
465: getchange(FILE *b)
466: {
467: char *line;
468:
469: while ((line = getline(b, NULL))) {
470: if (isdigit((unsigned char)line[0]))
471: return (line);
472: }
473:
474: return (NULL);
475: }
476:
477: static char *
478: getline(FILE *b, size_t *n)
479: {
480: char *cp;
481: size_t len;
482: static char *buf;
483: static size_t bufsize;
484:
485: if ((cp = fgetln(b, &len)) == NULL)
486: return (NULL);
487:
488: if (cp[len - 1] != '\n')
489: len++;
490: if (len + 1 > bufsize) {
1.22 ray 491: char *newbuf;
1.1 joris 492: do {
493: bufsize += 1024;
494: } while (len + 1 > bufsize);
1.22 ray 495: newbuf = xrealloc(buf, 1, bufsize);
496: buf = newbuf;
1.1 joris 497: }
498: memcpy(buf, cp, len - 1);
499: buf[len - 1] = '\n';
500: buf[len] = '\0';
501: if (n != NULL)
502: *n = len;
503:
504: return (buf);
505: }
506:
507: static int
1.20 ray 508: merge(size_t m1, size_t m2)
1.1 joris 509: {
510: struct diff *d1, *d2, *d3;
511: int dpl, j, t1, t2;
512:
513: d1 = d13;
514: d2 = d23;
515: j = 0;
516: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
517: if (debug) {
518: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 519: d1->old.from, d1->old.to,
520: d1->new.from, d1->new.to,
521: d2->old.from, d2->old.to,
522: d2->new.from, d2->new.to);
1.1 joris 523: }
524:
525: /* first file is different from others */
526: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
527: /* stuff peculiar to 1st file */
528: if (eflag==0) {
529: separate("1");
530: change(1, &d1->old, 0);
531: keep(2, &d1->new);
532: change(3, &d1->new, 0);
533: }
534: d1++;
535: continue;
536: }
537:
538: /* second file is different from others */
539: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
540: if (eflag==0) {
541: separate("2");
542: keep(1, &d2->new);
543: change(2, &d2->old, 0);
544: change(3, &d2->new, 0);
545: }
546: d2++;
547: continue;
548: }
549:
550: /*
551: * Merge overlapping changes in first file
552: * this happens after extension (see below).
553: */
554: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
555: d1[1].old.from = d1->old.from;
556: d1[1].new.from = d1->new.from;
557: d1++;
558: continue;
559: }
560:
561: /* merge overlapping changes in second */
562: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
563: d2[1].old.from = d2->old.from;
564: d2[1].new.from = d2->new.from;
565: d2++;
566: continue;
567: }
568: /* stuff peculiar to third file or different in all */
569: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
570: dpl = duplicate(&d1->old,&d2->old);
571: if (dpl == -1)
572: return (-1);
573:
574: /*
575: * dpl = 0 means all files differ
576: * dpl = 1 means files 1 and 2 identical
577: */
578: if (eflag==0) {
579: separate(dpl ? "3" : "");
580: change(1, &d1->old, dpl);
581: change(2, &d2->old, 0);
582: d3 = d1->old.to > d1->old.from ? d1 : d2;
583: change(3, &d3->new, 0);
584: } else
585: j = edit(d1, dpl, j);
586: d1++;
587: d2++;
588: continue;
589: }
590:
591: /*
592: * Overlapping changes from file 1 and 2; extend changes
593: * appropriately to make them coincide.
594: */
595: if (d1->new.from < d2->new.from) {
596: d2->old.from -= d2->new.from-d1->new.from;
597: d2->new.from = d1->new.from;
598: } else if (d2->new.from < d1->new.from) {
599: d1->old.from -= d1->new.from-d2->new.from;
600: d1->new.from = d2->new.from;
601: }
602: if (d1->new.to > d2->new.to) {
603: d2->old.to += d1->new.to - d2->new.to;
604: d2->new.to = d1->new.to;
605: } else if (d2->new.to > d1->new.to) {
606: d1->old.to += d2->new.to - d1->new.to;
607: d1->new.to = d2->new.to;
608: }
609: }
610:
611: return (edscript(j));
612: }
613:
614: static void
615: separate(const char *s)
616: {
617: diff_output("====%s\n", s);
618: }
619:
620: /*
621: * The range of lines rold.from thru rold.to in file i is to be changed.
622: * It is to be printed only if it does not duplicate something to be
623: * printed later.
624: */
625: static void
626: change(int i, struct range *rold, int fdup)
627: {
628: diff_output("%d:", i);
629: last[i] = rold->to;
630: prange(rold);
631: if (fdup || debug)
632: return;
633: i--;
634: (void)skip(i, rold->from, NULL);
635: (void)skip(i, rold->to, " ");
636: }
637:
638: /*
639: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
640: */
641: static void
642: prange(struct range *rold)
643: {
644: if (rold->to <= rold->from)
645: diff_output("%da\n", rold->from - 1);
646: else {
647: diff_output("%d", rold->from);
648: if (rold->to > rold->from+1)
649: diff_output(",%d", rold->to - 1);
650: diff_output("c\n");
651: }
652: }
653:
654: /*
655: * No difference was reported by diff between file 1 (or 2) and file 3,
656: * and an artificial dummy difference (trange) must be ginned up to
657: * correspond to the change reported in the other file.
658: */
659: static void
660: keep(int i, struct range *rnew)
661: {
662: int delta;
663: struct range trange;
664:
665: delta = last[3] - last[i];
666: trange.from = rnew->from - delta;
667: trange.to = rnew->to - delta;
668: change(i, &trange, 1);
669: }
670:
671: /*
672: * skip to just before line number from in file "i". If "pr" is non-NULL,
673: * print all skipped stuff with string pr as a prefix.
674: */
675: static int
676: skip(int i, int from, char *pr)
677: {
678: size_t j, n;
679: char *line;
680:
681: for (n = 0; cline[i] < from - 1; n += j) {
682: if ((line = getline(fp[i], &j)) == NULL)
683: return (-1);
684: if (pr != NULL)
685: diff_output("%s%s", pr, line);
686: cline[i]++;
687: }
688: return ((int) n);
689: }
690:
691: /*
692: * Return 1 or 0 according as the old range (in file 1) contains exactly
693: * the same data as the new range (in file 2).
694: */
695: static int
696: duplicate(struct range *r1, struct range *r2)
697: {
698: int c,d;
699: int nchar;
700: int nline;
701:
702: if (r1->to-r1->from != r2->to-r2->from)
703: return (0);
704: (void)skip(0, r1->from, NULL);
705: (void)skip(1, r2->from, NULL);
706: nchar = 0;
707: for (nline=0; nline < r1->to - r1->from; nline++) {
708: do {
709: c = getc(fp[0]);
710: d = getc(fp[1]);
711: if (c == -1 || d== -1)
712: return (-1);
713: nchar++;
714: if (c != d) {
715: repos(nchar);
716: return (0);
717: }
718: } while (c != '\n');
719: }
720: repos(nchar);
721: return (1);
722: }
723:
724: static void
725: repos(int nchar)
726: {
727: int i;
728:
729: for (i = 0; i < 2; i++)
730: (void)fseek(fp[i], (long)-nchar, 1);
731: }
732:
733: /*
734: * collect an editing script for later regurgitation
735: */
736: static int
737: edit(struct diff *diff, int fdup, int j)
738: {
739: if (((fdup + 1) & eflag) == 0)
740: return (j);
741: j++;
742: overlap[j] = !fdup;
743: if (!fdup)
744: overlapcnt++;
745: de[j].old.from = diff->old.from;
746: de[j].old.to = diff->old.to;
747: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
748: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
749: return (j);
750: }
751:
752: /* regurgitate */
753: static int
754: edscript(int n)
755: {
756: int j, k;
1.2 joris 757: char block[BUFSIZ+1];
1.1 joris 758:
759: for (n = n; n > 0; n--) {
760: if (!oflag || !overlap[n])
761: prange(&de[n].old);
762: else
763: diff_output("%da\n=======\n", de[n].old.to -1);
764: (void)fseek(fp[2], (long)de[n].new.from, 0);
765: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
766: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 767: if (fread(block, (size_t)1, (size_t)j,
768: fp[2]) != (size_t)j)
1.1 joris 769: return (-1);
770: block[j] = '\0';
771: diff_output("%s", block);
772: }
1.2 joris 773:
1.1 joris 774: if (!oflag || !overlap[n])
775: diff_output(".\n");
776: else {
777: diff_output("%s\n.\n", f3mark);
778: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
779: }
780: }
781:
782: return (overlapcnt);
783: }
784:
785: static void
786: increase(void)
787: {
788: struct diff *p;
789: char *q;
790: size_t newsz, incr;
791:
792: /* are the memset(3) calls needed? */
793: newsz = szchanges == 0 ? 64 : 2 * szchanges;
794: incr = newsz - szchanges;
795:
1.22 ray 796: p = xrealloc(d13, newsz, sizeof(*d13));
797: memset(p + szchanges, 0, incr * sizeof(*d13));
1.1 joris 798: d13 = p;
1.22 ray 799: p = xrealloc(d23, newsz, sizeof(*d23));
800: memset(p + szchanges, 0, incr * sizeof(*d23));
1.1 joris 801: d23 = p;
1.22 ray 802: p = xrealloc(de, newsz, sizeof(*de));
803: memset(p + szchanges, 0, incr * sizeof(*de));
1.1 joris 804: de = p;
1.22 ray 805: q = xrealloc(overlap, newsz, sizeof(*overlap));
806: memset(q + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 807: overlap = q;
808: szchanges = newsz;
809: }
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