Annotation of src/usr.bin/rcs/diff3.c, Revision 1.14
1.14 ! xsa 1: /* $OpenBSD: diff3.c,v 1.13 2006/08/08 10:22:01 espie 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
74: static const char rcsid[] =
1.14 ! xsa 75: "$OpenBSD: diff3.c,v 1.13 2006/08/08 10:22:01 espie Exp $";
1.1 joris 76: #endif /* not lint */
77:
78: #include "includes.h"
79:
80: #include "diff.h"
1.4 xsa 81: #include "rcsprog.h"
1.1 joris 82:
83: /* diff3 - 3-way differential file comparison */
84:
85: /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
86: *
87: * d13 = diff report on f1 vs f3
88: * d23 = diff report on f2 vs f3
89: * f1, f2, f3 the 3 files
90: * if changes in f1 overlap with changes in f3, m1 and m3 are used
91: * to mark the overlaps; otherwise, the file names f1 and f3 are used
92: * (only for options E and X).
93: */
94:
95: /*
96: * "from" is first in range of changed lines; "to" is last+1
97: * from=to=line after point of insertion for added lines.
98: */
99: struct range {
100: int from;
101: int to;
102: };
103:
104: struct diff {
105: struct range old;
106: struct range new;
107: };
108:
109: static size_t szchanges;
110:
111: static struct diff *d13;
112: static struct diff *d23;
113:
114: /*
115: * "de" is used to gather editing scripts. These are later spewed out in
116: * reverse order. Its first element must be all zero, the "new" component
117: * of "de" contains line positions or byte positions depending on when you
118: * look (!?). Array overlap indicates which sections in "de" correspond to
119: * lines that are different in all three files.
120: */
121: static struct diff *de;
122: static char *overlap;
123: static int overlapcnt = 0;
124: static FILE *fp[3];
125: static int cline[3]; /* # of the last-read line in each file (0-2) */
126:
127: /*
128: * the latest known correspondence between line numbers of the 3 files
129: * is stored in last[1-3];
130: */
131: static int last[4];
1.14 ! xsa 132: static int eflag = 3; /* default -E for compatibility with former RCS */
! 133: static int oflag = 1; /* default -E for compatibility with former RCS */
1.1 joris 134: static int debug = 0;
135: static char f1mark[40], f3mark[40]; /* markers for -E and -X */
136:
137: static int duplicate(struct range *, struct range *);
138: static int edit(struct diff *, int, int);
139: static char *getchange(FILE *);
140: static char *getline(FILE *, size_t *);
141: static int number(char **);
142: static size_t readin(char *, struct diff **);
143: static int skip(int, int, char *);
144: static int edscript(int);
145: static int merge(size_t, size_t);
146: static void change(int, struct range *, int);
147: static void keep(int, struct range *);
148: static void prange(struct range *);
149: static void repos(int);
150: static void separate(const char *);
151: static void increase(void);
152: static int diff3_internal(int, char **, const char *, const char *);
153:
154: int diff3_conflicts = 0;
1.9 xsa 155:
156: /*
157: * For merge(1).
158: */
159: BUF *
160: merge_diff3(char **av, int flags)
161: {
162: int argc;
163: char *argv[5], *dp13, *dp23, *path1, *path2, *path3;
164: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
165:
166: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
167: dp13 = dp23 = path1 = path2 = path3 = NULL;
168:
1.14 ! xsa 169: if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
! 170: oflag = 0;
! 171:
1.9 xsa 172: if ((b1 = rcs_buf_load(av[0], BUF_AUTOEXT)) == NULL)
173: goto out;
174: if ((b2 = rcs_buf_load(av[1], BUF_AUTOEXT)) == NULL)
175: goto out;
176: if ((b3 = rcs_buf_load(av[2], BUF_AUTOEXT)) == NULL)
177: goto out;
178:
179: d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
180: d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
181: diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
182:
183: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
184: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
185: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
186:
1.11 ray 187: rcs_buf_write_stmp(b1, path1);
188: rcs_buf_write_stmp(b2, path2);
189: rcs_buf_write_stmp(b3, path3);
1.9 xsa 190:
191: rcs_buf_free(b2);
192: b2 = NULL;
193:
194: if ((rcs_diffreg(path1, path3, d1) == D_ERROR) ||
195: (rcs_diffreg(path2, path3, d2) == D_ERROR)) {
196: rcs_buf_free(diffb);
197: diffb = NULL;
198: goto out;
199: }
200:
201: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 202: rcs_buf_write_stmp(d1, dp13);
1.9 xsa 203:
204: rcs_buf_free(d1);
205: d1 = NULL;
206:
207: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 208: rcs_buf_write_stmp(d2, dp23);
1.9 xsa 209:
210: rcs_buf_free(d2);
211: d2 = NULL;
212:
213: argc = 0;
214: diffbuf = diffb;
215: argv[argc++] = dp13;
216: argv[argc++] = dp23;
217: argv[argc++] = path1;
218: argv[argc++] = path2;
219: argv[argc++] = path3;
220:
221: diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]);
222: if (diff3_conflicts < 0) {
223: rcs_buf_free(diffb);
224: diffb = NULL;
225: goto out;
226: }
227:
228: rcs_buf_putc(diffb, '\0');
229: rcs_buf_putc(b1, '\0');
230:
1.10 niallo 231: if ((diffb = rcs_patchfile(b1, diffb, ed_patch_lines)) == NULL)
1.9 xsa 232: goto out;
233:
234: if (!(flags & QUIET) && diff3_conflicts != 0)
235: warnx("warning: overlaps or other problems during merge");
236:
237: out:
238: if (b2 != NULL)
239: rcs_buf_free(b2);
240: if (b3 != NULL)
241: rcs_buf_free(b3);
242: if (d1 != NULL)
243: rcs_buf_free(d1);
244: if (d2 != NULL)
245: rcs_buf_free(d2);
246:
247: (void)unlink(path1);
248: (void)unlink(path2);
249: (void)unlink(path3);
250: (void)unlink(dp13);
251: (void)unlink(dp23);
252:
253: if (path1 != NULL)
254: xfree(path1);
255: if (path2 != NULL)
256: xfree(path2);
257: if (path3 != NULL)
258: xfree(path3);
259: if (dp13 != NULL)
260: xfree(dp13);
261: if (dp23 != NULL)
262: xfree(dp23);
263:
264: return (diffb);
265: }
1.1 joris 266:
267: BUF *
1.14 ! xsa 268: rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags)
1.1 joris 269: {
270: int argc;
271: char *argv[5], r1[16], r2[16];
1.5 xsa 272: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 273: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
274:
275: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.7 xsa 276: dp13 = dp23 = path1 = path2 = path3 = NULL;
1.1 joris 277:
1.14 ! xsa 278: if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
! 279: oflag = 0;
! 280:
1.1 joris 281: rcsnum_tostr(rev1, r1, sizeof(r1));
282: rcsnum_tostr(rev2, r2, sizeof(r2));
283:
284: if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
285: goto out;
286:
1.14 ! xsa 287: if (!(flags & QUIET))
1.6 xsa 288: (void)fprintf(stderr, "retrieving revision %s\n", r1);
1.1 joris 289: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
290: goto out;
291:
1.14 ! xsa 292: if (!(flags & QUIET))
1.6 xsa 293: (void)fprintf(stderr, "retrieving revision %s\n", r2);
1.1 joris 294: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
295: goto out;
296:
1.8 ray 297: d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
298: d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
299: diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
1.1 joris 300:
1.5 xsa 301: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
302: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
303: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
1.3 ray 304:
1.11 ray 305: rcs_buf_write_stmp(b1, path1);
306: rcs_buf_write_stmp(b2, path2);
307: rcs_buf_write_stmp(b3, path3);
1.1 joris 308:
309: rcs_buf_free(b2);
310: b2 = NULL;
311:
1.7 xsa 312: if ((rcs_diffreg(path1, path3, d1) == D_ERROR) ||
313: (rcs_diffreg(path2, path3, d2) == D_ERROR)) {
314: rcs_buf_free(diffb);
315: diffb = NULL;
316: goto out;
317: }
1.1 joris 318:
1.5 xsa 319: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 320: rcs_buf_write_stmp(d1, dp13);
1.1 joris 321:
322: rcs_buf_free(d1);
323: d1 = NULL;
324:
1.5 xsa 325: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 326: rcs_buf_write_stmp(d2, dp23);
1.1 joris 327:
328: rcs_buf_free(d2);
329: d2 = NULL;
330:
331: argc = 0;
332: diffbuf = diffb;
333: argv[argc++] = dp13;
334: argv[argc++] = dp23;
335: argv[argc++] = path1;
336: argv[argc++] = path2;
337: argv[argc++] = path3;
338:
339: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
340: if (diff3_conflicts < 0) {
341: rcs_buf_free(diffb);
342: diffb = NULL;
343: goto out;
344: }
345:
346: rcs_buf_putc(diffb, '\0');
347: rcs_buf_putc(b1, '\0');
348:
1.10 niallo 349: if ((diffb = rcs_patchfile(b1, diffb, ed_patch_lines)) == NULL)
1.1 joris 350: goto out;
351:
1.14 ! xsa 352: if (!(flags & QUIET) && diff3_conflicts != 0)
1.6 xsa 353: warnx("warning: overlaps or other problems during merge");
1.1 joris 354:
355: out:
356: if (b2 != NULL)
357: rcs_buf_free(b2);
358: if (b3 != NULL)
359: rcs_buf_free(b3);
360: if (d1 != NULL)
361: rcs_buf_free(d1);
362: if (d2 != NULL)
363: rcs_buf_free(d2);
364:
365: (void)unlink(path1);
366: (void)unlink(path2);
367: (void)unlink(path3);
368: (void)unlink(dp13);
369: (void)unlink(dp23);
1.5 xsa 370:
371: if (path1 != NULL)
372: xfree(path1);
373: if (path2 != NULL)
374: xfree(path2);
375: if (path3 != NULL)
376: xfree(path3);
377: if (dp13 != NULL)
378: xfree(dp13);
379: if (dp23 != NULL)
380: xfree(dp23);
1.1 joris 381:
382: return (diffb);
383: }
384:
385: static int
386: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
387: {
388: size_t m, n;
389: int i;
390:
391: if (argc < 5)
392: return (-1);
393:
1.14 ! xsa 394: if (oflag) {
! 395: i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
! 396: if (i < 0 || i >= sizeof(f1mark))
! 397: errx(1, "diff3_internal: string truncated");
! 398:
! 399: i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
! 400: if (i < 0 || i >= sizeof(f3mark))
! 401: errx(1, "diff3_internal: string truncated");
! 402: }
1.1 joris 403:
404: increase();
405: m = readin(argv[0], &d13);
406: n = readin(argv[1], &d23);
407:
1.3 ray 408: for (i = 0; i <= 2; i++)
1.1 joris 409: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
410: warn("%s", argv[i + 2]);
411: return (-1);
412: }
413:
414: return (merge(m, n));
415: }
416:
417: int
418: ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
419: {
420: char op, *ep;
1.13 espie 421: struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.1 joris 422: int start, end, i, lineno;
423:
424: dlp = TAILQ_FIRST(&(dlines->l_lines));
425: lp = TAILQ_FIRST(&(plines->l_lines));
426:
427: end = 0;
428: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
429: lp = TAILQ_NEXT(lp, l_list)) {
430: op = lp->l_line[strlen(lp->l_line) - 1];
431: start = (int)strtol(lp->l_line, &ep, 10);
432: if (op == 'a') {
433: if (start > dlines->l_nblines ||
434: start < 0 || *ep != 'a')
435: errx(1, "ed_patch_lines");
436: } else if (op == 'c') {
437: if (start > dlines->l_nblines ||
438: start < 0 || (*ep != ',' && *ep != 'c'))
439: errx(1, "ed_patch_lines");
440:
441: if (*ep == ',') {
442: ep++;
443: end = (int)strtol(ep, &ep, 10);
444: if (end < 0 || *ep != 'c')
445: errx(1, "ed_patch_lines");
446: } else {
447: end = start;
448: }
449: }
450:
451:
452: for (;;) {
453: if (dlp == NULL)
454: break;
455: if (dlp->l_lineno == start)
456: break;
457: if (dlp->l_lineno > start) {
458: dlp = TAILQ_PREV(dlp, rcs_tqh, l_list);
459: } else if (dlp->l_lineno < start) {
460: ndlp = TAILQ_NEXT(dlp, l_list);
461: if (ndlp->l_lineno > start)
462: break;
463: dlp = ndlp;
464: }
465: }
466:
467: if (dlp == NULL)
468: errx(1, "ed_patch_lines");
469:
470:
471: if (op == 'c') {
1.13 espie 472: insert_after = TAILQ_PREV(dlp, rcs_tqh, l_list);
1.1 joris 473: for (i = 0; i <= (end - start); i++) {
474: ndlp = TAILQ_NEXT(dlp, l_list);
475: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
476: dlp = ndlp;
477: }
1.13 espie 478: dlp = insert_after;
1.1 joris 479: }
480:
481: if (op == 'a' || op == 'c') {
482: for (;;) {
483: ndlp = lp;
484: lp = TAILQ_NEXT(lp, l_list);
485: if (lp == NULL)
486: errx(1, "ed_patch_lines");
487:
488: if (!strcmp(lp->l_line, "."))
489: break;
490:
491: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
492: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
493: lp, l_list);
494: dlp = lp;
495:
496: lp->l_lineno = start;
497: lp = ndlp;
498: }
499: }
500:
501: /*
502: * always resort lines as the markers might be put at the
503: * same line as we first started editing.
504: */
505: lineno = 0;
506: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
507: sort->l_lineno = lineno++;
508: dlines->l_nblines = lineno - 1;
509: }
510:
511: return (0);
512: }
513:
514: /*
515: * Pick up the line numbers of all changes from one change file.
516: * (This puts the numbers in a vector, which is not strictly necessary,
517: * since the vector is processed in one sequential pass.
518: * The vector could be optimized out of existence)
519: */
520: static size_t
521: readin(char *name, struct diff **dd)
522: {
523: int a, b, c, d;
524: char kind, *p;
525: size_t i;
526:
527: fp[0] = fopen(name, "r");
528: for (i = 0; (p = getchange(fp[0])); i++) {
529: if (i >= szchanges - 1)
530: increase();
531: a = b = number(&p);
532: if (*p == ',') {
533: p++;
534: b = number(&p);
535: }
536: kind = *p++;
537: c = d = number(&p);
538: if (*p==',') {
539: p++;
540: d = number(&p);
541: }
542: if (kind == 'a')
543: a++;
544: if (kind == 'd')
545: c++;
546: b++;
547: d++;
548: (*dd)[i].old.from = a;
549: (*dd)[i].old.to = b;
550: (*dd)[i].new.from = c;
551: (*dd)[i].new.to = d;
552: }
553:
554: if (i) {
555: (*dd)[i].old.from = (*dd)[i-1].old.to;
556: (*dd)[i].new.from = (*dd)[i-1].new.to;
557: }
558: (void)fclose(fp[0]);
559:
560: return (i);
561: }
562:
563: static int
564: number(char **lc)
565: {
566: int nn;
567:
568: nn = 0;
569: while (isdigit((unsigned char)(**lc)))
570: nn = nn*10 + *(*lc)++ - '0';
571:
572: return (nn);
573: }
574:
575: static char *
576: getchange(FILE *b)
577: {
578: char *line;
579:
580: while ((line = getline(b, NULL))) {
581: if (isdigit((unsigned char)line[0]))
582: return (line);
583: }
584:
585: return (NULL);
586: }
587:
588: static char *
589: getline(FILE *b, size_t *n)
590: {
591: char *cp;
592: size_t len;
593: static char *buf;
594: static size_t bufsize;
595:
596: if ((cp = fgetln(b, &len)) == NULL)
597: return (NULL);
598:
599: if (cp[len - 1] != '\n')
600: len++;
601: if (len + 1 > bufsize) {
602: char *newbuf;
603: do {
604: bufsize += 1024;
605: } while (len + 1 > bufsize);
606: newbuf = xrealloc(buf, 1, bufsize);
607: buf = newbuf;
608: }
609: memcpy(buf, cp, len - 1);
610: buf[len - 1] = '\n';
611: buf[len] = '\0';
612: if (n != NULL)
613: *n = len;
614:
615: return (buf);
616: }
617:
618: static int
619: merge(size_t m1, size_t m2)
620: {
621: struct diff *d1, *d2, *d3;
622: int dpl, j, t1, t2;
623:
624: d1 = d13;
625: d2 = d23;
626: j = 0;
627: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
628: if (debug) {
629: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
630: d1->old.from, d1->old.to,
631: d1->new.from, d1->new.to,
632: d2->old.from, d2->old.to,
633: d2->new.from, d2->new.to);
634: }
635:
636: /* first file is different from others */
637: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
638: /* stuff peculiar to 1st file */
639: if (eflag==0) {
640: separate("1");
641: change(1, &d1->old, 0);
642: keep(2, &d1->new);
643: change(3, &d1->new, 0);
644: }
645: d1++;
646: continue;
647: }
648:
649: /* second file is different from others */
650: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
651: if (eflag==0) {
652: separate("2");
653: keep(1, &d2->new);
654: change(2, &d2->old, 0);
655: change(3, &d2->new, 0);
656: }
657: d2++;
658: continue;
659: }
660:
661: /*
662: * Merge overlapping changes in first file
663: * this happens after extension (see below).
664: */
665: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
666: d1[1].old.from = d1->old.from;
667: d1[1].new.from = d1->new.from;
668: d1++;
669: continue;
670: }
671:
672: /* merge overlapping changes in second */
673: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
674: d2[1].old.from = d2->old.from;
675: d2[1].new.from = d2->new.from;
676: d2++;
677: continue;
678: }
679: /* stuff peculiar to third file or different in all */
680: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
681: dpl = duplicate(&d1->old,&d2->old);
682: if (dpl == -1)
683: return (-1);
684:
685: /*
686: * dpl = 0 means all files differ
687: * dpl = 1 means files 1 and 2 identical
688: */
689: if (eflag==0) {
690: separate(dpl ? "3" : "");
691: change(1, &d1->old, dpl);
692: change(2, &d2->old, 0);
693: d3 = d1->old.to > d1->old.from ? d1 : d2;
694: change(3, &d3->new, 0);
695: } else
696: j = edit(d1, dpl, j);
697: d1++;
698: d2++;
699: continue;
700: }
701:
702: /*
703: * Overlapping changes from file 1 and 2; extend changes
704: * appropriately to make them coincide.
705: */
706: if (d1->new.from < d2->new.from) {
707: d2->old.from -= d2->new.from-d1->new.from;
708: d2->new.from = d1->new.from;
709: } else if (d2->new.from < d1->new.from) {
710: d1->old.from -= d1->new.from-d2->new.from;
711: d1->new.from = d2->new.from;
712: }
713: if (d1->new.to > d2->new.to) {
714: d2->old.to += d1->new.to - d2->new.to;
715: d2->new.to = d1->new.to;
716: } else if (d2->new.to > d1->new.to) {
717: d1->old.to += d2->new.to - d1->new.to;
718: d1->new.to = d2->new.to;
719: }
720: }
721:
722: return (edscript(j));
723: }
724:
725: static void
726: separate(const char *s)
727: {
728: diff_output("====%s\n", s);
729: }
730:
731: /*
732: * The range of lines rold.from thru rold.to in file i is to be changed.
733: * It is to be printed only if it does not duplicate something to be
734: * printed later.
735: */
736: static void
737: change(int i, struct range *rold, int fdup)
738: {
739: diff_output("%d:", i);
740: last[i] = rold->to;
741: prange(rold);
742: if (fdup || debug)
743: return;
744: i--;
745: (void)skip(i, rold->from, NULL);
746: (void)skip(i, rold->to, " ");
747: }
748:
749: /*
750: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
751: */
752: static void
753: prange(struct range *rold)
754: {
755: if (rold->to <= rold->from)
756: diff_output("%da\n", rold->from - 1);
757: else {
758: diff_output("%d", rold->from);
759: if (rold->to > rold->from+1)
760: diff_output(",%d", rold->to - 1);
761: diff_output("c\n");
762: }
763: }
764:
765: /*
766: * No difference was reported by diff between file 1 (or 2) and file 3,
767: * and an artificial dummy difference (trange) must be ginned up to
768: * correspond to the change reported in the other file.
769: */
770: static void
771: keep(int i, struct range *rnew)
772: {
773: int delta;
774: struct range trange;
775:
776: delta = last[3] - last[i];
777: trange.from = rnew->from - delta;
778: trange.to = rnew->to - delta;
779: change(i, &trange, 1);
780: }
781:
782: /*
783: * skip to just before line number from in file "i". If "pr" is non-NULL,
784: * print all skipped stuff with string pr as a prefix.
785: */
786: static int
787: skip(int i, int from, char *pr)
788: {
789: size_t j, n;
790: char *line;
791:
792: for (n = 0; cline[i] < from - 1; n += j) {
793: if ((line = getline(fp[i], &j)) == NULL)
794: return (-1);
795: if (pr != NULL)
796: diff_output("%s%s", pr, line);
797: cline[i]++;
798: }
799: return ((int) n);
800: }
801:
802: /*
803: * Return 1 or 0 according as the old range (in file 1) contains exactly
804: * the same data as the new range (in file 2).
805: */
806: static int
807: duplicate(struct range *r1, struct range *r2)
808: {
809: int c,d;
810: int nchar;
811: int nline;
812:
813: if (r1->to-r1->from != r2->to-r2->from)
814: return (0);
815: (void)skip(0, r1->from, NULL);
816: (void)skip(1, r2->from, NULL);
817: nchar = 0;
818: for (nline=0; nline < r1->to - r1->from; nline++) {
819: do {
820: c = getc(fp[0]);
821: d = getc(fp[1]);
822: if (c == -1 || d== -1)
823: return (-1);
824: nchar++;
825: if (c != d) {
826: repos(nchar);
827: return (0);
828: }
829: } while (c != '\n');
830: }
831: repos(nchar);
832: return (1);
833: }
834:
835: static void
836: repos(int nchar)
837: {
838: int i;
839:
840: for (i = 0; i < 2; i++)
841: (void)fseek(fp[i], (long)-nchar, 1);
842: }
843:
844: /*
845: * collect an editing script for later regurgitation
846: */
847: static int
848: edit(struct diff *diff, int fdup, int j)
849: {
850: if (((fdup + 1) & eflag) == 0)
851: return (j);
852: j++;
853: overlap[j] = !fdup;
854: if (!fdup)
855: overlapcnt++;
856: de[j].old.from = diff->old.from;
857: de[j].old.to = diff->old.to;
858: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
859: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
860: return (j);
861: }
862:
863: /* regurgitate */
864: static int
865: edscript(int n)
866: {
867: int j, k;
868: char block[BUFSIZ+1];
869:
870: for (n = n; n > 0; n--) {
871: if (!oflag || !overlap[n])
872: prange(&de[n].old);
873: else
874: diff_output("%da\n=======\n", de[n].old.to -1);
875: (void)fseek(fp[2], (long)de[n].new.from, 0);
876: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
877: j = k > BUFSIZ ? BUFSIZ : k;
1.8 ray 878: if (fread(block, 1, (size_t)j,
1.1 joris 879: fp[2]) != (size_t)j)
880: return (-1);
881: block[j] = '\0';
882: diff_output("%s", block);
883: }
884:
885: if (!oflag || !overlap[n])
886: diff_output(".\n");
887: else {
888: diff_output("%s\n.\n", f3mark);
889: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
890: }
891: }
892:
893: return (overlapcnt);
894: }
895:
896: static void
897: increase(void)
898: {
899: struct diff *p;
900: char *q;
901: size_t newsz, incr;
902:
903: /* are the memset(3) calls needed? */
904: newsz = szchanges == 0 ? 64 : 2 * szchanges;
905: incr = newsz - szchanges;
906:
907: p = xrealloc(d13, newsz, sizeof(*d13));
908: memset(p + szchanges, 0, incr * sizeof(*d13));
909: d13 = p;
910: p = xrealloc(d23, newsz, sizeof(*d23));
911: memset(p + szchanges, 0, incr * sizeof(*d23));
912: d23 = p;
913: p = xrealloc(de, newsz, sizeof(*de));
914: memset(p + szchanges, 0, incr * sizeof(*de));
915: de = p;
916: q = xrealloc(overlap, newsz, sizeof(*overlap));
917: memset(q + szchanges, 0, incr * sizeof(*overlap));
918: overlap = q;
919: szchanges = newsz;
920: }
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