Annotation of src/usr.bin/cvs/diff3.c, Revision 1.31
1.31 ! joris 1: /* $OpenBSD: diff3.c,v 1.30 2007/01/11 17:44:18 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[] =
1.31 ! joris 75: "$OpenBSD: diff3.c,v 1.30 2007/01/11 17:44:18 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;
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;
1.30 niallo 166: size_t dlen, plen;
1.1 joris 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:
1.28 xsa 190: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", cvs_tmpdir);
191: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", cvs_tmpdir);
192: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", cvs_tmpdir);
193:
1.26 ray 194: cvs_buf_write_stmp(b1, path1, NULL);
195: cvs_buf_write_stmp(b2, path2, NULL);
196: cvs_buf_write_stmp(b3, path3, NULL);
1.1 joris 197:
198: cvs_buf_free(b2);
199: b2 = NULL;
200:
201: cvs_diffreg(path1, path3, d1);
202: cvs_diffreg(path2, path3, d2);
203:
1.28 xsa 204: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 205: cvs_buf_write_stmp(d1, dp13, NULL);
1.1 joris 206:
207: cvs_buf_free(d1);
208: d1 = NULL;
209:
1.28 xsa 210: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", cvs_tmpdir);
1.26 ray 211: cvs_buf_write_stmp(d2, dp23, NULL);
1.1 joris 212:
213: cvs_buf_free(d2);
214: d2 = NULL;
215:
216: argc = 0;
217: diffbuf = diffb;
218: argv[argc++] = dp13;
219: argv[argc++] = dp23;
220: argv[argc++] = path1;
221: argv[argc++] = path2;
222: argv[argc++] = path3;
1.7 joris 223:
224: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
225: if (diff3_conflicts < 0) {
226: cvs_buf_free(diffb);
227: diffb = NULL;
1.1 joris 228: goto out;
1.7 joris 229: }
1.1 joris 230:
1.30 niallo 231: plen = cvs_buf_len(diffb);
1.1 joris 232: patch = cvs_buf_release(diffb);
1.30 niallo 233: dlen = cvs_buf_len(b1);
1.1 joris 234: data = cvs_buf_release(b1);
235: diffb = b1 = NULL;
236:
1.30 niallo 237: if ((diffb = cvs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL)
1.1 joris 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:
1.29 xsa 294: i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
295: if (i < 0 ||i >= (int)sizeof(f1mark))
296: fatal("diff3_internal: truncation");
297:
298: i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
299: if (i < 0 ||i >= (int)sizeof(f3mark))
300: fatal("diff3_internal: truncation");
1.1 joris 301:
302: increase();
303: m = readin(argv[0], &d13);
304: n = readin(argv[1], &d23);
305:
306: for (i = 0; i <= 2; i++) {
307: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
1.24 joris 308: cvs_log(LP_ERR, "%s", argv[i + 2]);
1.1 joris 309: return (-1);
310: }
311: }
312:
313: return (merge(m, n));
314: }
315:
316: int
317: ed_patch_lines(struct cvs_lines *dlines, struct cvs_lines *plines)
318: {
319: char op, *ep;
1.29 xsa 320: struct cvs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.19 xsa 321: int start, end, i, lineno;
1.30 niallo 322: u_char tmp;
1.1 joris 323:
324: dlp = TAILQ_FIRST(&(dlines->l_lines));
325: lp = TAILQ_FIRST(&(plines->l_lines));
326:
1.19 xsa 327: end = 0;
1.1 joris 328: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
329: lp = TAILQ_NEXT(lp, l_list)) {
1.30 niallo 330: /* Skip blank lines */
331: if (lp->l_len < 2)
332: continue;
333: /* NUL-terminate line buffer for strtol() safety. */
334: tmp = lp->l_line[lp->l_len - 1];
335: lp->l_line[lp->l_len - 1] = '\0';
336: /* len - 1 is NUL terminator so we use len - 2 for 'op' */
1.1 joris 337: op = lp->l_line[strlen(lp->l_line) - 1];
338: start = (int)strtol(lp->l_line, &ep, 10);
1.30 niallo 339: /* Restore the last byte of the buffer */
340: lp->l_line[lp->l_len - 1] = tmp;
1.1 joris 341: if (op == 'a') {
1.23 deraadt 342: if (start > dlines->l_nblines ||
343: start < 0 || *ep != 'a')
1.15 niallo 344: fatal("ed_patch_lines");
1.1 joris 345: } else if (op == 'c') {
1.23 deraadt 346: if (start > dlines->l_nblines ||
347: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 348: fatal("ed_patch_lines");
1.1 joris 349:
1.2 joris 350: if (*ep == ',') {
351: ep++;
352: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 353: if (end < 0 || *ep != 'c')
1.15 niallo 354: fatal("ed_patch_lines");
1.2 joris 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)
1.15 niallo 377: fatal("ed_patch_lines");
1.1 joris 378:
1.2 joris 379:
1.1 joris 380: if (op == 'c') {
1.29 xsa 381: insert_after = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.2 joris 382: for (i = 0; i <= (end - start); i++) {
1.1 joris 383: ndlp = TAILQ_NEXT(dlp, l_list);
384: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
385: dlp = ndlp;
386: }
1.29 xsa 387: dlp = insert_after;
1.1 joris 388: }
389:
390: if (op == 'a' || op == 'c') {
391: for (;;) {
392: ndlp = lp;
393: lp = TAILQ_NEXT(lp, l_list);
394: if (lp == NULL)
1.15 niallo 395: fatal("ed_patch_lines");
1.1 joris 396:
1.30 niallo 397: if (!memcmp(lp->l_line, ".", 1))
1.1 joris 398: break;
399:
400: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
401: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
402: lp, l_list);
403: dlp = lp;
404:
405: lp->l_lineno = start;
406: lp = ndlp;
407: }
408: }
409:
410: /*
411: * always resort lines as the markers might be put at the
412: * same line as we first started editing.
413: */
414: lineno = 0;
415: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
416: sort->l_lineno = lineno++;
417: dlines->l_nblines = lineno - 1;
418: }
419:
420: return (0);
421: }
422:
423: /*
424: * Pick up the line numbers of all changes from one change file.
425: * (This puts the numbers in a vector, which is not strictly necessary,
426: * since the vector is processed in one sequential pass.
427: * The vector could be optimized out of existence)
428: */
1.20 ray 429: static size_t
1.1 joris 430: readin(char *name, struct diff **dd)
431: {
432: int a, b, c, d;
433: char kind, *p;
434: size_t i;
435:
436: fp[0] = fopen(name, "r");
437: for (i = 0; (p = getchange(fp[0])); i++) {
438: if (i >= szchanges - 1)
439: increase();
440: a = b = number(&p);
441: if (*p == ',') {
442: p++;
443: b = number(&p);
444: }
445: kind = *p++;
446: c = d = number(&p);
447: if (*p==',') {
448: p++;
449: d = number(&p);
450: }
451: if (kind == 'a')
452: a++;
453: if (kind == 'd')
454: c++;
455: b++;
456: d++;
457: (*dd)[i].old.from = a;
458: (*dd)[i].old.to = b;
459: (*dd)[i].new.from = c;
460: (*dd)[i].new.to = d;
461: }
462:
1.14 xsa 463: if (i) {
464: (*dd)[i].old.from = (*dd)[i-1].old.to;
465: (*dd)[i].new.from = (*dd)[i-1].new.to;
466: }
1.1 joris 467: (void)fclose(fp[0]);
468:
469: return (i);
470: }
471:
472: static int
473: number(char **lc)
474: {
475: int nn;
476:
477: nn = 0;
478: while (isdigit((unsigned char)(**lc)))
479: nn = nn*10 + *(*lc)++ - '0';
480:
481: return (nn);
482: }
483:
484: static char *
485: getchange(FILE *b)
486: {
487: char *line;
488:
489: while ((line = getline(b, NULL))) {
490: if (isdigit((unsigned char)line[0]))
491: return (line);
492: }
493:
494: return (NULL);
495: }
496:
497: static char *
498: getline(FILE *b, size_t *n)
499: {
500: char *cp;
501: size_t len;
502: static char *buf;
503: static size_t bufsize;
504:
505: if ((cp = fgetln(b, &len)) == NULL)
506: return (NULL);
507:
508: if (cp[len - 1] != '\n')
509: len++;
510: if (len + 1 > bufsize) {
1.22 ray 511: char *newbuf;
1.1 joris 512: do {
513: bufsize += 1024;
514: } while (len + 1 > bufsize);
1.22 ray 515: newbuf = xrealloc(buf, 1, bufsize);
516: buf = newbuf;
1.1 joris 517: }
518: memcpy(buf, cp, len - 1);
519: buf[len - 1] = '\n';
520: buf[len] = '\0';
521: if (n != NULL)
522: *n = len;
523:
524: return (buf);
525: }
526:
527: static int
1.20 ray 528: merge(size_t m1, size_t m2)
1.1 joris 529: {
530: struct diff *d1, *d2, *d3;
531: int dpl, j, t1, t2;
532:
533: d1 = d13;
534: d2 = d23;
535: j = 0;
536: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
537: if (debug) {
538: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 539: d1->old.from, d1->old.to,
540: d1->new.from, d1->new.to,
541: d2->old.from, d2->old.to,
542: d2->new.from, d2->new.to);
1.1 joris 543: }
544:
545: /* first file is different from others */
546: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
547: /* stuff peculiar to 1st file */
548: if (eflag==0) {
549: separate("1");
550: change(1, &d1->old, 0);
551: keep(2, &d1->new);
552: change(3, &d1->new, 0);
553: }
554: d1++;
555: continue;
556: }
557:
558: /* second file is different from others */
559: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
560: if (eflag==0) {
561: separate("2");
562: keep(1, &d2->new);
563: change(2, &d2->old, 0);
564: change(3, &d2->new, 0);
565: }
566: d2++;
567: continue;
568: }
569:
570: /*
571: * Merge overlapping changes in first file
572: * this happens after extension (see below).
573: */
574: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
575: d1[1].old.from = d1->old.from;
576: d1[1].new.from = d1->new.from;
577: d1++;
578: continue;
579: }
580:
581: /* merge overlapping changes in second */
582: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
583: d2[1].old.from = d2->old.from;
584: d2[1].new.from = d2->new.from;
585: d2++;
586: continue;
587: }
588: /* stuff peculiar to third file or different in all */
589: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
590: dpl = duplicate(&d1->old,&d2->old);
591: if (dpl == -1)
592: return (-1);
593:
594: /*
595: * dpl = 0 means all files differ
596: * dpl = 1 means files 1 and 2 identical
597: */
598: if (eflag==0) {
599: separate(dpl ? "3" : "");
600: change(1, &d1->old, dpl);
601: change(2, &d2->old, 0);
602: d3 = d1->old.to > d1->old.from ? d1 : d2;
603: change(3, &d3->new, 0);
604: } else
605: j = edit(d1, dpl, j);
606: d1++;
607: d2++;
608: continue;
609: }
610:
611: /*
612: * Overlapping changes from file 1 and 2; extend changes
613: * appropriately to make them coincide.
614: */
615: if (d1->new.from < d2->new.from) {
616: d2->old.from -= d2->new.from-d1->new.from;
617: d2->new.from = d1->new.from;
618: } else if (d2->new.from < d1->new.from) {
619: d1->old.from -= d1->new.from-d2->new.from;
620: d1->new.from = d2->new.from;
621: }
622: if (d1->new.to > d2->new.to) {
623: d2->old.to += d1->new.to - d2->new.to;
624: d2->new.to = d1->new.to;
625: } else if (d2->new.to > d1->new.to) {
626: d1->old.to += d2->new.to - d1->new.to;
627: d1->new.to = d2->new.to;
628: }
629: }
630:
631: return (edscript(j));
632: }
633:
634: static void
635: separate(const char *s)
636: {
637: diff_output("====%s\n", s);
638: }
639:
640: /*
641: * The range of lines rold.from thru rold.to in file i is to be changed.
642: * It is to be printed only if it does not duplicate something to be
643: * printed later.
644: */
645: static void
646: change(int i, struct range *rold, int fdup)
647: {
648: diff_output("%d:", i);
649: last[i] = rold->to;
650: prange(rold);
651: if (fdup || debug)
652: return;
653: i--;
654: (void)skip(i, rold->from, NULL);
655: (void)skip(i, rold->to, " ");
656: }
657:
658: /*
659: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
660: */
661: static void
662: prange(struct range *rold)
663: {
664: if (rold->to <= rold->from)
665: diff_output("%da\n", rold->from - 1);
666: else {
667: diff_output("%d", rold->from);
668: if (rold->to > rold->from+1)
669: diff_output(",%d", rold->to - 1);
670: diff_output("c\n");
671: }
672: }
673:
674: /*
675: * No difference was reported by diff between file 1 (or 2) and file 3,
676: * and an artificial dummy difference (trange) must be ginned up to
677: * correspond to the change reported in the other file.
678: */
679: static void
680: keep(int i, struct range *rnew)
681: {
682: int delta;
683: struct range trange;
684:
685: delta = last[3] - last[i];
686: trange.from = rnew->from - delta;
687: trange.to = rnew->to - delta;
688: change(i, &trange, 1);
689: }
690:
691: /*
692: * skip to just before line number from in file "i". If "pr" is non-NULL,
693: * print all skipped stuff with string pr as a prefix.
694: */
695: static int
696: skip(int i, int from, char *pr)
697: {
698: size_t j, n;
699: char *line;
700:
701: for (n = 0; cline[i] < from - 1; n += j) {
702: if ((line = getline(fp[i], &j)) == NULL)
703: return (-1);
704: if (pr != NULL)
705: diff_output("%s%s", pr, line);
706: cline[i]++;
707: }
708: return ((int) n);
709: }
710:
711: /*
712: * Return 1 or 0 according as the old range (in file 1) contains exactly
713: * the same data as the new range (in file 2).
714: */
715: static int
716: duplicate(struct range *r1, struct range *r2)
717: {
718: int c,d;
719: int nchar;
720: int nline;
721:
722: if (r1->to-r1->from != r2->to-r2->from)
723: return (0);
724: (void)skip(0, r1->from, NULL);
725: (void)skip(1, r2->from, NULL);
726: nchar = 0;
727: for (nline=0; nline < r1->to - r1->from; nline++) {
728: do {
729: c = getc(fp[0]);
730: d = getc(fp[1]);
731: if (c == -1 || d== -1)
732: return (-1);
733: nchar++;
734: if (c != d) {
735: repos(nchar);
736: return (0);
737: }
738: } while (c != '\n');
739: }
740: repos(nchar);
741: return (1);
742: }
743:
744: static void
745: repos(int nchar)
746: {
747: int i;
748:
749: for (i = 0; i < 2; i++)
750: (void)fseek(fp[i], (long)-nchar, 1);
751: }
752:
753: /*
754: * collect an editing script for later regurgitation
755: */
756: static int
757: edit(struct diff *diff, int fdup, int j)
758: {
759: if (((fdup + 1) & eflag) == 0)
760: return (j);
761: j++;
762: overlap[j] = !fdup;
763: if (!fdup)
764: overlapcnt++;
765: de[j].old.from = diff->old.from;
766: de[j].old.to = diff->old.to;
767: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
768: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
769: return (j);
770: }
771:
772: /* regurgitate */
773: static int
774: edscript(int n)
775: {
776: int j, k;
1.2 joris 777: char block[BUFSIZ+1];
1.1 joris 778:
779: for (n = n; n > 0; n--) {
780: if (!oflag || !overlap[n])
781: prange(&de[n].old);
782: else
783: diff_output("%da\n=======\n", de[n].old.to -1);
784: (void)fseek(fp[2], (long)de[n].new.from, 0);
785: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
786: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 787: if (fread(block, (size_t)1, (size_t)j,
788: fp[2]) != (size_t)j)
1.1 joris 789: return (-1);
790: block[j] = '\0';
791: diff_output("%s", block);
792: }
1.2 joris 793:
1.1 joris 794: if (!oflag || !overlap[n])
795: diff_output(".\n");
796: else {
797: diff_output("%s\n.\n", f3mark);
798: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
799: }
800: }
801:
802: return (overlapcnt);
803: }
804:
805: static void
806: increase(void)
807: {
808: struct diff *p;
809: char *q;
810: size_t newsz, incr;
811:
812: /* are the memset(3) calls needed? */
813: newsz = szchanges == 0 ? 64 : 2 * szchanges;
814: incr = newsz - szchanges;
815:
1.22 ray 816: p = xrealloc(d13, newsz, sizeof(*d13));
817: memset(p + szchanges, 0, incr * sizeof(*d13));
1.1 joris 818: d13 = p;
1.22 ray 819: p = xrealloc(d23, newsz, sizeof(*d23));
820: memset(p + szchanges, 0, incr * sizeof(*d23));
1.1 joris 821: d23 = p;
1.22 ray 822: p = xrealloc(de, newsz, sizeof(*de));
823: memset(p + szchanges, 0, incr * sizeof(*de));
1.1 joris 824: de = p;
1.22 ray 825: q = xrealloc(overlap, newsz, sizeof(*overlap));
826: memset(q + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 827: overlap = q;
828: szchanges = newsz;
829: }
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