Annotation of src/usr.bin/cvs/diff3.c, Revision 1.26
1.26 ! ray 1: /* $OpenBSD: diff3.c,v 1.25 2006/06/14 14:10:50 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
1.11 reyk 74: static const char rcsid[] =
1.26 ! ray 75: "$OpenBSD: diff3.c,v 1.25 2006/06/14 14:10:50 joris 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)) {
318: op = lp->l_line[strlen(lp->l_line) - 1];
319: start = (int)strtol(lp->l_line, &ep, 10);
320: if (op == 'a') {
1.23 deraadt 321: if (start > dlines->l_nblines ||
322: start < 0 || *ep != 'a')
1.15 niallo 323: fatal("ed_patch_lines");
1.1 joris 324: } else if (op == 'c') {
1.23 deraadt 325: if (start > dlines->l_nblines ||
326: start < 0 || (*ep != ',' && *ep != 'c'))
1.15 niallo 327: fatal("ed_patch_lines");
1.1 joris 328:
1.2 joris 329: if (*ep == ',') {
330: ep++;
331: end = (int)strtol(ep, &ep, 10);
1.23 deraadt 332: if (end < 0 || *ep != 'c')
1.15 niallo 333: fatal("ed_patch_lines");
1.2 joris 334: } else {
335: end = start;
336: }
1.1 joris 337: }
338:
1.2 joris 339:
1.1 joris 340: for (;;) {
341: if (dlp == NULL)
342: break;
343: if (dlp->l_lineno == start)
344: break;
345: if (dlp->l_lineno > start) {
346: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
347: } else if (dlp->l_lineno < start) {
348: ndlp = TAILQ_NEXT(dlp, l_list);
349: if (ndlp->l_lineno > start)
350: break;
351: dlp = ndlp;
352: }
353: }
354:
355: if (dlp == NULL)
1.15 niallo 356: fatal("ed_patch_lines");
1.1 joris 357:
1.2 joris 358:
1.1 joris 359: if (op == 'c') {
1.2 joris 360: for (i = 0; i <= (end - start); i++) {
1.1 joris 361: ndlp = TAILQ_NEXT(dlp, l_list);
362: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
363: dlp = ndlp;
364: }
1.2 joris 365: dlp = TAILQ_PREV(dlp, cvs_tqh, l_list);
1.1 joris 366: }
367:
368: if (op == 'a' || op == 'c') {
369: for (;;) {
370: ndlp = lp;
371: lp = TAILQ_NEXT(lp, l_list);
372: if (lp == NULL)
1.15 niallo 373: fatal("ed_patch_lines");
1.1 joris 374:
375: if (!strcmp(lp->l_line, "."))
376: break;
377:
378: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
379: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
380: lp, l_list);
381: dlp = lp;
382:
383: lp->l_lineno = start;
384: lp = ndlp;
385: }
386: }
387:
388: /*
389: * always resort lines as the markers might be put at the
390: * same line as we first started editing.
391: */
392: lineno = 0;
393: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
394: sort->l_lineno = lineno++;
395: dlines->l_nblines = lineno - 1;
396: }
397:
398: return (0);
399: }
400:
401: /*
402: * Pick up the line numbers of all changes from one change file.
403: * (This puts the numbers in a vector, which is not strictly necessary,
404: * since the vector is processed in one sequential pass.
405: * The vector could be optimized out of existence)
406: */
1.20 ray 407: static size_t
1.1 joris 408: readin(char *name, struct diff **dd)
409: {
410: int a, b, c, d;
411: char kind, *p;
412: size_t i;
413:
414: fp[0] = fopen(name, "r");
415: for (i = 0; (p = getchange(fp[0])); i++) {
416: if (i >= szchanges - 1)
417: increase();
418: a = b = number(&p);
419: if (*p == ',') {
420: p++;
421: b = number(&p);
422: }
423: kind = *p++;
424: c = d = number(&p);
425: if (*p==',') {
426: p++;
427: d = number(&p);
428: }
429: if (kind == 'a')
430: a++;
431: if (kind == 'd')
432: c++;
433: b++;
434: d++;
435: (*dd)[i].old.from = a;
436: (*dd)[i].old.to = b;
437: (*dd)[i].new.from = c;
438: (*dd)[i].new.to = d;
439: }
440:
1.14 xsa 441: if (i) {
442: (*dd)[i].old.from = (*dd)[i-1].old.to;
443: (*dd)[i].new.from = (*dd)[i-1].new.to;
444: }
1.1 joris 445: (void)fclose(fp[0]);
446:
447: return (i);
448: }
449:
450: static int
451: number(char **lc)
452: {
453: int nn;
454:
455: nn = 0;
456: while (isdigit((unsigned char)(**lc)))
457: nn = nn*10 + *(*lc)++ - '0';
458:
459: return (nn);
460: }
461:
462: static char *
463: getchange(FILE *b)
464: {
465: char *line;
466:
467: while ((line = getline(b, NULL))) {
468: if (isdigit((unsigned char)line[0]))
469: return (line);
470: }
471:
472: return (NULL);
473: }
474:
475: static char *
476: getline(FILE *b, size_t *n)
477: {
478: char *cp;
479: size_t len;
480: static char *buf;
481: static size_t bufsize;
482:
483: if ((cp = fgetln(b, &len)) == NULL)
484: return (NULL);
485:
486: if (cp[len - 1] != '\n')
487: len++;
488: if (len + 1 > bufsize) {
1.22 ray 489: char *newbuf;
1.1 joris 490: do {
491: bufsize += 1024;
492: } while (len + 1 > bufsize);
1.22 ray 493: newbuf = xrealloc(buf, 1, bufsize);
494: buf = newbuf;
1.1 joris 495: }
496: memcpy(buf, cp, len - 1);
497: buf[len - 1] = '\n';
498: buf[len] = '\0';
499: if (n != NULL)
500: *n = len;
501:
502: return (buf);
503: }
504:
505: static int
1.20 ray 506: merge(size_t m1, size_t m2)
1.1 joris 507: {
508: struct diff *d1, *d2, *d3;
509: int dpl, j, t1, t2;
510:
511: d1 = d13;
512: d2 = d23;
513: j = 0;
514: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
515: if (debug) {
516: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
1.20 ray 517: d1->old.from, d1->old.to,
518: d1->new.from, d1->new.to,
519: d2->old.from, d2->old.to,
520: d2->new.from, d2->new.to);
1.1 joris 521: }
522:
523: /* first file is different from others */
524: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
525: /* stuff peculiar to 1st file */
526: if (eflag==0) {
527: separate("1");
528: change(1, &d1->old, 0);
529: keep(2, &d1->new);
530: change(3, &d1->new, 0);
531: }
532: d1++;
533: continue;
534: }
535:
536: /* second file is different from others */
537: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
538: if (eflag==0) {
539: separate("2");
540: keep(1, &d2->new);
541: change(2, &d2->old, 0);
542: change(3, &d2->new, 0);
543: }
544: d2++;
545: continue;
546: }
547:
548: /*
549: * Merge overlapping changes in first file
550: * this happens after extension (see below).
551: */
552: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
553: d1[1].old.from = d1->old.from;
554: d1[1].new.from = d1->new.from;
555: d1++;
556: continue;
557: }
558:
559: /* merge overlapping changes in second */
560: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
561: d2[1].old.from = d2->old.from;
562: d2[1].new.from = d2->new.from;
563: d2++;
564: continue;
565: }
566: /* stuff peculiar to third file or different in all */
567: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
568: dpl = duplicate(&d1->old,&d2->old);
569: if (dpl == -1)
570: return (-1);
571:
572: /*
573: * dpl = 0 means all files differ
574: * dpl = 1 means files 1 and 2 identical
575: */
576: if (eflag==0) {
577: separate(dpl ? "3" : "");
578: change(1, &d1->old, dpl);
579: change(2, &d2->old, 0);
580: d3 = d1->old.to > d1->old.from ? d1 : d2;
581: change(3, &d3->new, 0);
582: } else
583: j = edit(d1, dpl, j);
584: d1++;
585: d2++;
586: continue;
587: }
588:
589: /*
590: * Overlapping changes from file 1 and 2; extend changes
591: * appropriately to make them coincide.
592: */
593: if (d1->new.from < d2->new.from) {
594: d2->old.from -= d2->new.from-d1->new.from;
595: d2->new.from = d1->new.from;
596: } else if (d2->new.from < d1->new.from) {
597: d1->old.from -= d1->new.from-d2->new.from;
598: d1->new.from = d2->new.from;
599: }
600: if (d1->new.to > d2->new.to) {
601: d2->old.to += d1->new.to - d2->new.to;
602: d2->new.to = d1->new.to;
603: } else if (d2->new.to > d1->new.to) {
604: d1->old.to += d2->new.to - d1->new.to;
605: d1->new.to = d2->new.to;
606: }
607: }
608:
609: return (edscript(j));
610: }
611:
612: static void
613: separate(const char *s)
614: {
615: diff_output("====%s\n", s);
616: }
617:
618: /*
619: * The range of lines rold.from thru rold.to in file i is to be changed.
620: * It is to be printed only if it does not duplicate something to be
621: * printed later.
622: */
623: static void
624: change(int i, struct range *rold, int fdup)
625: {
626: diff_output("%d:", i);
627: last[i] = rold->to;
628: prange(rold);
629: if (fdup || debug)
630: return;
631: i--;
632: (void)skip(i, rold->from, NULL);
633: (void)skip(i, rold->to, " ");
634: }
635:
636: /*
637: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
638: */
639: static void
640: prange(struct range *rold)
641: {
642: if (rold->to <= rold->from)
643: diff_output("%da\n", rold->from - 1);
644: else {
645: diff_output("%d", rold->from);
646: if (rold->to > rold->from+1)
647: diff_output(",%d", rold->to - 1);
648: diff_output("c\n");
649: }
650: }
651:
652: /*
653: * No difference was reported by diff between file 1 (or 2) and file 3,
654: * and an artificial dummy difference (trange) must be ginned up to
655: * correspond to the change reported in the other file.
656: */
657: static void
658: keep(int i, struct range *rnew)
659: {
660: int delta;
661: struct range trange;
662:
663: delta = last[3] - last[i];
664: trange.from = rnew->from - delta;
665: trange.to = rnew->to - delta;
666: change(i, &trange, 1);
667: }
668:
669: /*
670: * skip to just before line number from in file "i". If "pr" is non-NULL,
671: * print all skipped stuff with string pr as a prefix.
672: */
673: static int
674: skip(int i, int from, char *pr)
675: {
676: size_t j, n;
677: char *line;
678:
679: for (n = 0; cline[i] < from - 1; n += j) {
680: if ((line = getline(fp[i], &j)) == NULL)
681: return (-1);
682: if (pr != NULL)
683: diff_output("%s%s", pr, line);
684: cline[i]++;
685: }
686: return ((int) n);
687: }
688:
689: /*
690: * Return 1 or 0 according as the old range (in file 1) contains exactly
691: * the same data as the new range (in file 2).
692: */
693: static int
694: duplicate(struct range *r1, struct range *r2)
695: {
696: int c,d;
697: int nchar;
698: int nline;
699:
700: if (r1->to-r1->from != r2->to-r2->from)
701: return (0);
702: (void)skip(0, r1->from, NULL);
703: (void)skip(1, r2->from, NULL);
704: nchar = 0;
705: for (nline=0; nline < r1->to - r1->from; nline++) {
706: do {
707: c = getc(fp[0]);
708: d = getc(fp[1]);
709: if (c == -1 || d== -1)
710: return (-1);
711: nchar++;
712: if (c != d) {
713: repos(nchar);
714: return (0);
715: }
716: } while (c != '\n');
717: }
718: repos(nchar);
719: return (1);
720: }
721:
722: static void
723: repos(int nchar)
724: {
725: int i;
726:
727: for (i = 0; i < 2; i++)
728: (void)fseek(fp[i], (long)-nchar, 1);
729: }
730:
731: /*
732: * collect an editing script for later regurgitation
733: */
734: static int
735: edit(struct diff *diff, int fdup, int j)
736: {
737: if (((fdup + 1) & eflag) == 0)
738: return (j);
739: j++;
740: overlap[j] = !fdup;
741: if (!fdup)
742: overlapcnt++;
743: de[j].old.from = diff->old.from;
744: de[j].old.to = diff->old.to;
745: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
746: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
747: return (j);
748: }
749:
750: /* regurgitate */
751: static int
752: edscript(int n)
753: {
754: int j, k;
1.2 joris 755: char block[BUFSIZ+1];
1.1 joris 756:
757: for (n = n; n > 0; n--) {
758: if (!oflag || !overlap[n])
759: prange(&de[n].old);
760: else
761: diff_output("%da\n=======\n", de[n].old.to -1);
762: (void)fseek(fp[2], (long)de[n].new.from, 0);
763: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
764: j = k > BUFSIZ ? BUFSIZ : k;
1.11 reyk 765: if (fread(block, (size_t)1, (size_t)j,
766: fp[2]) != (size_t)j)
1.1 joris 767: return (-1);
768: block[j] = '\0';
769: diff_output("%s", block);
770: }
1.2 joris 771:
1.1 joris 772: if (!oflag || !overlap[n])
773: diff_output(".\n");
774: else {
775: diff_output("%s\n.\n", f3mark);
776: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
777: }
778: }
779:
780: return (overlapcnt);
781: }
782:
783: static void
784: increase(void)
785: {
786: struct diff *p;
787: char *q;
788: size_t newsz, incr;
789:
790: /* are the memset(3) calls needed? */
791: newsz = szchanges == 0 ? 64 : 2 * szchanges;
792: incr = newsz - szchanges;
793:
1.22 ray 794: p = xrealloc(d13, newsz, sizeof(*d13));
795: memset(p + szchanges, 0, incr * sizeof(*d13));
1.1 joris 796: d13 = p;
1.22 ray 797: p = xrealloc(d23, newsz, sizeof(*d23));
798: memset(p + szchanges, 0, incr * sizeof(*d23));
1.1 joris 799: d23 = p;
1.22 ray 800: p = xrealloc(de, newsz, sizeof(*de));
801: memset(p + szchanges, 0, incr * sizeof(*de));
1.1 joris 802: de = p;
1.22 ray 803: q = xrealloc(overlap, newsz, sizeof(*overlap));
804: memset(q + szchanges, 0, incr * sizeof(*overlap));
1.1 joris 805: overlap = q;
806: szchanges = newsz;
807: }
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