Annotation of src/usr.bin/cvs/diff3.c, Revision 1.28
1.28 ! xsa 1: /* $OpenBSD: diff3.c,v 1.27 2006/10/24 06:22:53 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[] =
1.28 ! xsa 75: "$OpenBSD: diff3.c,v 1.27 2006/10/24 06:22:53 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];
1.28 ! xsa 164: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 165: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
166:
167: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
168:
169: rcsnum_tostr(rev1, r1, sizeof(r1));
170: rcsnum_tostr(rev2, r2, sizeof(r2));
171:
1.25 joris 172: if ((b1 = cvs_buf_load_fd(workfd, BUF_AUTOEXT)) == NULL)
1.1 joris 173: goto out;
174:
1.18 xsa 175: if (verbose == 1)
176: cvs_printf("Retrieving revision %s\n", r1);
1.1 joris 177: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
178: goto out;
179:
1.18 xsa 180: if (verbose == 1)
181: cvs_printf("Retrieving revision %s\n", r2);
1.1 joris 182: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
183: goto out;
184:
1.10 joris 185: d1 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
186: d2 = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
187: diffb = cvs_buf_alloc((size_t)128, BUF_AUTOEXT);
1.1 joris 188:
1.28 ! xsa 189: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
! 190: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
! 191: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
! 192:
1.26 ray 193: cvs_buf_write_stmp(b1, path1, NULL);
194: cvs_buf_write_stmp(b2, path2, NULL);
195: cvs_buf_write_stmp(b3, path3, NULL);
1.1 joris 196:
197: cvs_buf_free(b2);
198: b2 = NULL;
199:
200: cvs_diffreg(path1, path3, d1);
201: cvs_diffreg(path2, path3, d2);
202:
1.28 ! xsa 203: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 204: cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 205:
206: cvs_buf_free(d1);
207: d1 = NULL;
208:
1.28 ! xsa 209: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 210: cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 211:
212: cvs_buf_free(d2);
213: d2 = NULL;
214:
215: argc = 0;
216: diffbuf = diffb;
217: argv[argc++] = dp13;
218: argv[argc++] = dp23;
219: argv[argc++] = path1;
220: argv[argc++] = path2;
221: argv[argc++] = path3;
1.7 joris 222:
223: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
224: if (diff3_conflicts < 0) {
225: cvs_buf_free(diffb);
226: diffb = NULL;
1.1 joris 227: goto out;
1.7 joris 228: }
1.1 joris 229:
1.9 xsa 230: cvs_buf_putc(diffb, '\0');
231: cvs_buf_putc(b1, '\0');
1.1 joris 232:
233: patch = cvs_buf_release(diffb);
234: data = cvs_buf_release(b1);
235: diffb = b1 = NULL;
236:
237: if ((diffb = cvs_patchfile(data, patch, ed_patch_lines)) == NULL)
238: goto out;
1.7 joris 239:
1.23 deraadt 240: if (verbose == 1 && diff3_conflicts != 0) {
1.24 joris 241: cvs_log(LP_ERR, "%d conflict%s found during merge, "
1.16 xsa 242: "please correct.", diff3_conflicts,
1.11 reyk 243: (diff3_conflicts > 1) ? "s" : "");
1.7 joris 244: }
1.1 joris 245:
1.8 joris 246: xfree(data);
247: xfree(patch);
1.1 joris 248:
249: out:
250: if (b1 != NULL)
251: cvs_buf_free(b1);
252: if (b2 != NULL)
253: cvs_buf_free(b2);
254: if (b3 != NULL)
255: cvs_buf_free(b3);
256: if (d1 != NULL)
257: cvs_buf_free(d1);
258: if (d2 != NULL)
259: cvs_buf_free(d2);
260:
261: (void)unlink(path1);
262: (void)unlink(path2);
263: (void)unlink(path3);
264: (void)unlink(dp13);
265: (void)unlink(dp23);
1.28 ! xsa 266:
! 267: if (path1 != NULL)
! 268: xfree(path1);
! 269: if (path2 != NULL)
! 270: xfree(path2);
! 271: if (path3 != NULL)
! 272: xfree(path3);
! 273: if (dp13 != NULL)
! 274: xfree(dp13);
! 275: if (dp23 != NULL)
! 276: xfree(dp23);
1.1 joris 277:
278: return (diffb);
279: }
280:
281: static int
282: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
283: {
1.20 ray 284: size_t m, n;
285: int i;
1.1 joris 286:
287: /* XXX */
288: eflag = 3;
289: oflag = 1;
290:
291: if (argc < 5)
292: return (-1);
293:
1.13 xsa 294: strlcpy(f1mark, "<<<<<<< ", sizeof(f1mark));
295: strlcat(f1mark, fmark, sizeof(f1mark));
296:
297: strlcpy(f3mark, ">>>>>>> ", sizeof(f3mark));
298: strlcat(f3mark, rmark, sizeof(f3mark));
1.1 joris 299:
300: increase();
301: m = readin(argv[0], &d13);
302: n = readin(argv[1], &d23);
303:
304: for (i = 0; i <= 2; i++) {
305: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
1.24 joris 306: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 307: return (-1);
308: }
309: }
310:
311: return (merge(m, n));
312: }
313:
314: int
315: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
316: {
317: char op, *ep;
318: struct cvs_line *sort, *lp, *dlp, *ndlp;
1.19 xsa 319: int start, end, i, lineno;
1.1 joris 320:
321: dlp = TAILQ_FIRST(&(dlines->l_lines));
322: lp = TAILQ_FIRST(&(plines->l_lines));
323:
1.19 xsa 324: end = 0;
1.1 joris 325: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
326: lp = TAILQ_NEXT(lp, l_list)) {
1.27 ray 327: if (lp->l_line[0] == '\0')
328: fatal("ed_patch_lines");
1.1 joris 329: op = lp->l_line[strlen(lp->l_line) - 1];
330: start = (int)strtol(lp->l_line, &ep, 10);
331: if (op == 'a') {
1.23 deraadt 332: if (start > dlines->l_nblines ||
333: start < 0 || *ep != 'a')
1.15 niallo 334: fatal("ed_patch_lines");
1.1 joris 335: } else if (op == 'c') {
1.23 deraadt 336: if (start > dlines->l_nblines ||
337: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 338: fatal("ed_patch_lines");
1.1 joris 339:
1.2 joris 340: if (*ep == ',') {
341: ep++;
342: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 343: if (end < 0 || *ep != 'c')
1.15 niallo 344: fatal("ed_patch_lines");
1.2 joris 345: } else {
346: end = start;
347: }
1.1 joris 348: }
349:
1.2 joris 350:
1.1 joris 351: for (;;) {
352: if (dlp == NULL)
353: break;
354: if (dlp->l_lineno == start)
355: break;
356: if (dlp->l_lineno > start) {
357: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
358: } else if (dlp->l_lineno < start) {
359: ndlp = TAILQ_NEXT(dlp, l_list);
360: if (ndlp->l_lineno > start)
361: break;
362: dlp = ndlp;
363: }
364: }
365:
366: if (dlp == NULL)
1.15 niallo 367: fatal("ed_patch_lines");
1.1 joris 368:
1.2 joris 369:
1.1 joris 370: if (op == 'c') {
1.2 joris 371: for (i = 0; i <= (end - start); i++) {
1.1 joris 372: ndlp = TAILQ_NEXT(dlp, l_list);
373: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
374: dlp = ndlp;
375: }
1.2 joris 376: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.1 joris 377: }
378:
379: if (op == 'a' || op == 'c') {
380: for (;;) {
381: ndlp = lp;
382: lp = TAILQ_NEXT(lp, l_list);
383: if (lp == NULL)
1.15 niallo 384: fatal("ed_patch_lines");
1.1 joris 385:
386: if (!strcmp(lp->l_line, "."))
387: break;
388:
389: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
390: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
391: lp, l_list);
392: dlp = lp;
393:
394: lp->l_lineno = start;
395: lp = ndlp;
396: }
397: }
398:
399: /*
400: * always resort lines as the markers might be put at the
401: * same line as we first started editing.
402: */
403: lineno = 0;
404: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
405: sort->l_lineno = lineno++;
406: dlines->l_nblines = lineno - 1;
407: }
408:
409: return (0);
410: }
411:
412: /*
413: * Pick up the line numbers of all changes from one change file.
414: * (This puts the numbers in a vector, which is not strictly necessary,
415: * since the vector is processed in one sequential pass.
416: * The vector could be optimized out of existence)
417: */
1.20 ray 418: static size_t
1.1 joris 419: readin(char *name, struct diff **dd)
420: {
421: int a, b, c, d;
422: char kind, *p;
423: size_t i;
424:
425: fp[0] = fopen(name, "r");
426: for (i = 0; (p = getchange(fp[0])); i++) {
427: if (i >= szchanges - 1)
428: increase();
429: a = b = number(&p);
430: if (*p == ',') {
431: p++;
432: b = number(&p);
433: }
434: kind = *p++;
435: c = d = number(&p);
436: if (*p==',') {
437: p++;
438: d = number(&p);
439: }
440: if (kind == 'a')
441: a++;
442: if (kind == 'd')
443: c++;
444: b++;
445: d++;
446: (*dd)[i].old.from = a;
447: (*dd)[i].old.to = b;
448: (*dd)[i].new.from = c;
449: (*dd)[i].new.to = d;
450: }
451:
1.14 xsa 452: if (i) {
453: (*dd)[i].old.from = (*dd)[i-1].old.to;
454: (*dd)[i].new.from = (*dd)[i-1].new.to;
455: }
1.1 joris 456: (void)fclose(fp[0]);
457:
458: return (i);
459: }
460:
461: static int
462: number(char **lc)
463: {
464: int nn;
465:
466: nn = 0;
467: while (isdigit((unsigned char)(**lc)))
468: nn = nn*10 + *(*lc)++ - '0';
469:
470: return (nn);
471: }
472:
473: static char *
474: getchange(FILE *b)
475: {
476: char *line;
477:
478: while ((line = getline(b, NULL))) {
479: if (isdigit((unsigned char)line[0]))
480: return (line);
481: }
482:
483: return (NULL);
484: }
485:
486: static char *
487: getline(FILE *b, size_t *n)
488: {
489: char *cp;
490: size_t len;
491: static char *buf;
492: static size_t bufsize;
493:
494: if ((cp = fgetln(b, &len)) == NULL)
495: return (NULL);
496:
497: if (cp[len - 1] != '\n')
498: len++;
499: if (len + 1 > bufsize) {
1.22 ray 500: char *newbuf;
1.1 joris 501: do {
502: bufsize += 1024;
503: } while (len + 1 > bufsize);
1.22 ray 504: newbuf = xrealloc(buf, 1, bufsize);
505: buf = newbuf;
1.1 joris 506: }
507: memcpy(buf, cp, len - 1);
508: buf[len - 1] = '\n';
509: buf[len] = '\0';
510: if (n != NULL)
511: *n = len;
512:
513: return (buf);
514: }
515:
516: static int
1.20 ray 517: merge(size_t m1, size_t m2)
1.1 joris 518: {
519: struct diff *d1, *d2, *d3;
520: int dpl, j, t1, t2;
521:
522: d1 = d13;
523: d2 = d23;
524: j = 0;
525: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
526: if (debug) {
527: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 528: d1->old.from, d1->old.to,
529: d1->new.from, d1->new.to,
530: d2->old.from, d2->old.to,
531: d2->new.from, d2->new.to);
1.1 joris 532: }
533:
534: /* first file is different from others */
535: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
536: /* stuff peculiar to 1st file */
537: if (eflag==0) {
538: separate("1");
539: change(1, &d1->old, 0);
540: keep(2, &d1->new);
541: change(3, &d1->new, 0);
542: }
543: d1++;
544: continue;
545: }
546:
547: /* second file is different from others */
548: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
549: if (eflag==0) {
550: separate("2");
551: keep(1, &d2->new);
552: change(2, &d2->old, 0);
553: change(3, &d2->new, 0);
554: }
555: d2++;
556: continue;
557: }
558:
559: /*
560: * Merge overlapping changes in first file
561: * this happens after extension (see below).
562: */
563: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
564: d1[1].old.from = d1->old.from;
565: d1[1].new.from = d1->new.from;
566: d1++;
567: continue;
568: }
569:
570: /* merge overlapping changes in second */
571: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
572: d2[1].old.from = d2->old.from;
573: d2[1].new.from = d2->new.from;
574: d2++;
575: continue;
576: }
577: /* stuff peculiar to third file or different in all */
578: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
579: dpl = duplicate(&d1->old,&d2->old);
580: if (dpl == -1)
581: return (-1);
582:
583: /*
584: * dpl = 0 means all files differ
585: * dpl = 1 means files 1 and 2 identical
586: */
587: if (eflag==0) {
588: separate(dpl ? "3" : "");
589: change(1, &d1->old, dpl);
590: change(2, &d2->old, 0);
591: d3 = d1->old.to > d1->old.from ? d1 : d2;
592: change(3, &d3->new, 0);
593: } else
594: j = edit(d1, dpl, j);
595: d1++;
596: d2++;
597: continue;
598: }
599:
600: /*
601: * Overlapping changes from file 1 and 2; extend changes
602: * appropriately to make them coincide.
603: */
604: if (d1->new.from < d2->new.from) {
605: d2->old.from -= d2->new.from-d1->new.from;
606: d2->new.from = d1->new.from;
607: } else if (d2->new.from < d1->new.from) {
608: d1->old.from -= d1->new.from-d2->new.from;
609: d1->new.from = d2->new.from;
610: }
611: if (d1->new.to > d2->new.to) {
612: d2->old.to += d1->new.to - d2->new.to;
613: d2->new.to = d1->new.to;
614: } else if (d2->new.to > d1->new.to) {
615: d1->old.to += d2->new.to - d1->new.to;
616: d1->new.to = d2->new.to;
617: }
618: }
619:
620: return (edscript(j));
621: }
622:
623: static void
624: separate(const char *s)
625: {
626: diff_output("====%s\n", s);
627: }
628:
629: /*
630: * The range of lines rold.from thru rold.to in file i is to be changed.
631: * It is to be printed only if it does not duplicate something to be
632: * printed later.
633: */
634: static void
635: change(int i, struct range *rold, int fdup)
636: {
637: diff_output("%d:", i);
638: last[i] = rold->to;
639: prange(rold);
640: if (fdup || debug)
641: return;
642: i--;
643: (void)skip(i, rold->from, NULL);
644: (void)skip(i, rold->to, " ");
645: }
646:
647: /*
648: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
649: */
650: static void
651: prange(struct range *rold)
652: {
653: if (rold->to <= rold->from)
654: diff_output("%da\n", rold->from - 1);
655: else {
656: diff_output("%d", rold->from);
657: if (rold->to > rold->from+1)
658: diff_output(",%d", rold->to - 1);
659: diff_output("c\n");
660: }
661: }
662:
663: /*
664: * No difference was reported by diff between file 1 (or 2) and file 3,
665: * and an artificial dummy difference (trange) must be ginned up to
666: * correspond to the change reported in the other file.
667: */
668: static void
669: keep(int i, struct range *rnew)
670: {
671: int delta;
672: struct range trange;
673:
674: delta = last[3] - last[i];
675: trange.from = rnew->from - delta;
676: trange.to = rnew->to - delta;
677: change(i, &trange, 1);
678: }
679:
680: /*
681: * skip to just before line number from in file "i". If "pr" is non-NULL,
682: * print all skipped stuff with string pr as a prefix.
683: */
684: static int
685: skip(int i, int from, char *pr)
686: {
687: size_t j, n;
688: char *line;
689:
690: for (n = 0; cline[i] < from - 1; n += j) {
691: if ((line = getline(fp[i], &j)) == NULL)
692: return (-1);
693: if (pr != NULL)
694: diff_output("%s%s", pr, line);
695: cline[i]++;
696: }
697: return ((int) n);
698: }
699:
700: /*
701: * Return 1 or 0 according as the old range (in file 1) contains exactly
702: * the same data as the new range (in file 2).
703: */
704: static int
705: duplicate(struct range *r1, struct range *r2)
706: {
707: int c,d;
708: int nchar;
709: int nline;
710:
711: if (r1->to-r1->from != r2->to-r2->from)
712: return (0);
713: (void)skip(0, r1->from, NULL);
714: (void)skip(1, r2->from, NULL);
715: nchar = 0;
716: for (nline=0; nline < r1->to - r1->from; nline++) {
717: do {
718: c = getc(fp[0]);
719: d = getc(fp[1]);
720: if (c == -1 || d== -1)
721: return (-1);
722: nchar++;
723: if (c != d) {
724: repos(nchar);
725: return (0);
726: }
727: } while (c != '\n');
728: }
729: repos(nchar);
730: return (1);
731: }
732:
733: static void
734: repos(int nchar)
735: {
736: int i;
737:
738: for (i = 0; i < 2; i++)
739: (void)fseek(fp[i], (long)-nchar, 1);
740: }
741:
742: /*
743: * collect an editing script for later regurgitation
744: */
745: static int
746: edit(struct diff *diff, int fdup, int j)
747: {
748: if (((fdup + 1) & eflag) == 0)
749: return (j);
750: j++;
751: overlap[j] = !fdup;
752: if (!fdup)
753: overlapcnt++;
754: de[j].old.from = diff->old.from;
755: de[j].old.to = diff->old.to;
756: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
757: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
758: return (j);
759: }
760:
761: /* regurgitate */
762: static int
763: edscript(int n)
764: {
765: int j, k;
1.2 joris 766: char block[BUFSIZ+1];
1.1 joris 767:
768: for (n = n; n > 0; n--) {
769: if (!oflag || !overlap[n])
770: prange(&de[n].old);
771: else
772: diff_output("%da\n=======\n", de[n].old.to -1);
773: (void)fseek(fp[2], (long)de[n].new.from, 0);
774: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
775: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 776: if (fread(block, (size_t)1, (size_t)j,
777: fp[2]) != (size_t)j)
1.1 joris 778: return (-1);
779: block[j] = '\0';
780: diff_output("%s", block);
781: }
1.2 joris 782:
1.1 joris 783: if (!oflag || !overlap[n])
784: diff_output(".\n");
785: else {
786: diff_output("%s\n.\n", f3mark);
787: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
788: }
789: }
790:
791: return (overlapcnt);
792: }
793:
794: static void
795: increase(void)
796: {
797: struct diff *p;
798: char *q;
799: size_t newsz, incr;
800:
801: /* are the memset(3) calls needed? */
802: newsz = szchanges == 0 ? 64 : 2 * szchanges;
803: incr = newsz - szchanges;
804:
1.22 ray 805: p = xrealloc(d13, newsz, sizeof(*d13));
806: memset(p + szchanges, 0, incr * sizeof(*d13));
1.1 joris 807: d13 = p;
1.22 ray 808: p = xrealloc(d23, newsz, sizeof(*d23));
809: memset(p + szchanges, 0, incr * sizeof(*d23));
1.1 joris 810: d23 = p;
1.22 ray 811: p = xrealloc(de, newsz, sizeof(*de));
812: memset(p + szchanges, 0, incr * sizeof(*de));
1.1 joris 813: de = p;
1.22 ray 814: q = xrealloc(overlap, newsz, sizeof(*overlap));
815: memset(q + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 816: overlap = q;
817: szchanges = newsz;
818: }
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