Annotation of src/usr.bin/rcs/diff3.c, Revision 1.19
1.19 ! xsa 1: /* $OpenBSD: diff3.c,v 1.18 2007/01/11 18:13:33 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
74: static const char rcsid[] =
1.19 ! xsa 75: "$OpenBSD: diff3.c,v 1.18 2007/01/11 18:13:33 niallo 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;
1.17 niallo 165: u_char *data, *patch;
166: size_t dlen, plen;
1.9 xsa 167:
168: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
169: dp13 = dp23 = path1 = path2 = path3 = NULL;
1.17 niallo 170: data = patch = NULL;
1.9 xsa 171:
1.14 xsa 172: if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
173: oflag = 0;
174:
1.9 xsa 175: if ((b1 = rcs_buf_load(av[0], BUF_AUTOEXT)) == NULL)
176: goto out;
177: if ((b2 = rcs_buf_load(av[1], BUF_AUTOEXT)) == NULL)
178: goto out;
179: if ((b3 = rcs_buf_load(av[2], BUF_AUTOEXT)) == NULL)
180: goto out;
181:
182: d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
183: d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
184: diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
185:
186: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
187: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
188: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
189:
1.11 ray 190: rcs_buf_write_stmp(b1, path1);
191: rcs_buf_write_stmp(b2, path2);
192: rcs_buf_write_stmp(b3, path3);
1.9 xsa 193:
194: rcs_buf_free(b2);
195: b2 = NULL;
196:
1.15 millert 197: if ((rcs_diffreg(path1, path3, d1, 0) == D_ERROR) ||
198: (rcs_diffreg(path2, path3, d2, 0) == D_ERROR)) {
1.9 xsa 199: rcs_buf_free(diffb);
200: diffb = NULL;
201: goto out;
202: }
203:
204: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 205: rcs_buf_write_stmp(d1, dp13);
1.9 xsa 206:
207: rcs_buf_free(d1);
208: d1 = NULL;
209:
210: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 211: rcs_buf_write_stmp(d2, dp23);
1.9 xsa 212:
213: rcs_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;
223:
224: diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]);
225: if (diff3_conflicts < 0) {
226: rcs_buf_free(diffb);
227: diffb = NULL;
228: goto out;
229: }
230:
1.17 niallo 231: plen = rcs_buf_len(diffb);
232: patch = rcs_buf_release(diffb);
233: dlen = rcs_buf_len(b1);
234: data = rcs_buf_release(b1);
235:
236: if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL)
1.9 xsa 237: goto out;
238:
239: if (!(flags & QUIET) && diff3_conflicts != 0)
240: warnx("warning: overlaps or other problems during merge");
241:
242: out:
243: if (b2 != NULL)
244: rcs_buf_free(b2);
245: if (b3 != NULL)
246: rcs_buf_free(b3);
247: if (d1 != NULL)
248: rcs_buf_free(d1);
249: if (d2 != NULL)
250: rcs_buf_free(d2);
251:
252: (void)unlink(path1);
253: (void)unlink(path2);
254: (void)unlink(path3);
255: (void)unlink(dp13);
256: (void)unlink(dp23);
257:
258: if (path1 != NULL)
259: xfree(path1);
260: if (path2 != NULL)
261: xfree(path2);
262: if (path3 != NULL)
263: xfree(path3);
264: if (dp13 != NULL)
265: xfree(dp13);
266: if (dp23 != NULL)
267: xfree(dp23);
1.17 niallo 268: if (data != NULL)
269: xfree(data);
270: if (patch != NULL)
271: xfree(patch);
1.9 xsa 272:
273: return (diffb);
274: }
1.1 joris 275:
276: BUF *
1.14 xsa 277: rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags)
1.1 joris 278: {
279: int argc;
280: char *argv[5], r1[16], r2[16];
1.5 xsa 281: char *dp13, *dp23, *path1, *path2, *path3;
1.1 joris 282: BUF *b1, *b2, *b3, *d1, *d2, *diffb;
1.17 niallo 283: size_t dlen, plen;
284: u_char *data, *patch;
1.1 joris 285:
286: b1 = b2 = b3 = d1 = d2 = diffb = NULL;
1.7 xsa 287: dp13 = dp23 = path1 = path2 = path3 = NULL;
1.17 niallo 288: data = patch = NULL;
1.1 joris 289:
1.14 xsa 290: if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
291: oflag = 0;
292:
1.1 joris 293: rcsnum_tostr(rev1, r1, sizeof(r1));
294: rcsnum_tostr(rev2, r2, sizeof(r2));
295:
296: if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
297: goto out;
298:
1.14 xsa 299: if (!(flags & QUIET))
1.6 xsa 300: (void)fprintf(stderr, "retrieving revision %s\n", r1);
1.1 joris 301: if ((b2 = rcs_getrev(rf, rev1)) == NULL)
302: goto out;
303:
1.14 xsa 304: if (!(flags & QUIET))
1.6 xsa 305: (void)fprintf(stderr, "retrieving revision %s\n", r2);
1.1 joris 306: if ((b3 = rcs_getrev(rf, rev2)) == NULL)
307: goto out;
308:
1.8 ray 309: d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
310: d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
311: diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
1.1 joris 312:
1.5 xsa 313: (void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
314: (void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
315: (void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
1.3 ray 316:
1.11 ray 317: rcs_buf_write_stmp(b1, path1);
318: rcs_buf_write_stmp(b2, path2);
319: rcs_buf_write_stmp(b3, path3);
1.1 joris 320:
321: rcs_buf_free(b2);
322: b2 = NULL;
323:
1.15 millert 324: if ((rcs_diffreg(path1, path3, d1, 0) == D_ERROR) ||
325: (rcs_diffreg(path2, path3, d2, 0) == D_ERROR)) {
1.7 xsa 326: rcs_buf_free(diffb);
327: diffb = NULL;
328: goto out;
329: }
1.1 joris 330:
1.5 xsa 331: (void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 332: rcs_buf_write_stmp(d1, dp13);
1.1 joris 333:
334: rcs_buf_free(d1);
335: d1 = NULL;
336:
1.5 xsa 337: (void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
1.11 ray 338: rcs_buf_write_stmp(d2, dp23);
1.1 joris 339:
340: rcs_buf_free(d2);
341: d2 = NULL;
342:
343: argc = 0;
344: diffbuf = diffb;
345: argv[argc++] = dp13;
346: argv[argc++] = dp23;
347: argv[argc++] = path1;
348: argv[argc++] = path2;
349: argv[argc++] = path3;
350:
351: diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
352: if (diff3_conflicts < 0) {
353: rcs_buf_free(diffb);
354: diffb = NULL;
355: goto out;
356: }
357:
1.17 niallo 358: plen = rcs_buf_len(diffb);
359: patch = rcs_buf_release(diffb);
360: dlen = rcs_buf_len(b1);
361: data = rcs_buf_release(b1);
362:
363: if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL)
1.1 joris 364: goto out;
365:
1.14 xsa 366: if (!(flags & QUIET) && diff3_conflicts != 0)
1.6 xsa 367: warnx("warning: overlaps or other problems during merge");
1.1 joris 368:
369: out:
370: if (b2 != NULL)
371: rcs_buf_free(b2);
372: if (b3 != NULL)
373: rcs_buf_free(b3);
374: if (d1 != NULL)
375: rcs_buf_free(d1);
376: if (d2 != NULL)
377: rcs_buf_free(d2);
378:
379: (void)unlink(path1);
380: (void)unlink(path2);
381: (void)unlink(path3);
382: (void)unlink(dp13);
383: (void)unlink(dp23);
1.5 xsa 384:
385: if (path1 != NULL)
386: xfree(path1);
387: if (path2 != NULL)
388: xfree(path2);
389: if (path3 != NULL)
390: xfree(path3);
391: if (dp13 != NULL)
392: xfree(dp13);
393: if (dp23 != NULL)
394: xfree(dp23);
1.17 niallo 395: if (data != NULL)
396: xfree(data);
397: if (patch != NULL)
398: xfree(patch);
1.1 joris 399:
400: return (diffb);
401: }
402:
403: static int
404: diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
405: {
406: size_t m, n;
407: int i;
408:
409: if (argc < 5)
410: return (-1);
411:
1.14 xsa 412: if (oflag) {
413: i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
1.19 ! xsa 414: if (i < 0 || i >= (int)sizeof(f1mark))
1.14 xsa 415: errx(1, "diff3_internal: string truncated");
416:
417: i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
1.19 ! xsa 418: if (i < 0 || i >= (int)sizeof(f3mark))
1.14 xsa 419: errx(1, "diff3_internal: string truncated");
420: }
1.1 joris 421:
422: increase();
423: m = readin(argv[0], &d13);
424: n = readin(argv[1], &d23);
425:
1.3 ray 426: for (i = 0; i <= 2; i++)
1.1 joris 427: if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
428: warn("%s", argv[i + 2]);
429: return (-1);
430: }
431:
432: return (merge(m, n));
433: }
434:
435: int
436: ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
437: {
438: char op, *ep;
1.13 espie 439: struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after;
1.1 joris 440: int start, end, i, lineno;
1.17 niallo 441: u_char tmp;
1.1 joris 442:
443: dlp = TAILQ_FIRST(&(dlines->l_lines));
444: lp = TAILQ_FIRST(&(plines->l_lines));
445:
446: end = 0;
447: for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
448: lp = TAILQ_NEXT(lp, l_list)) {
1.17 niallo 449: /* Skip blank lines */
450: if (lp->l_len < 2)
451: continue;
452: /* NUL-terminate line buffer for strtol() safety. */
453: tmp = lp->l_line[lp->l_len - 1];
454: lp->l_line[lp->l_len - 1] = '\0';
455: /* len - 1 is NUL terminator so we use len - 2 for 'op' */
456: op = lp->l_line[lp->l_len - 2];
1.1 joris 457: start = (int)strtol(lp->l_line, &ep, 10);
1.17 niallo 458: /* Restore the last byte of the buffer */
459: lp->l_line[lp->l_len - 1] = tmp;
1.1 joris 460: if (op == 'a') {
461: if (start > dlines->l_nblines ||
462: start < 0 || *ep != 'a')
463: errx(1, "ed_patch_lines");
464: } else if (op == 'c') {
465: if (start > dlines->l_nblines ||
466: start < 0 || (*ep != ',' && *ep != 'c'))
467: errx(1, "ed_patch_lines");
468:
469: if (*ep == ',') {
470: ep++;
471: end = (int)strtol(ep, &ep, 10);
472: if (end < 0 || *ep != 'c')
473: errx(1, "ed_patch_lines");
474: } else {
475: end = start;
476: }
477: }
478:
479:
480: for (;;) {
481: if (dlp == NULL)
482: break;
483: if (dlp->l_lineno == start)
484: break;
485: if (dlp->l_lineno > start) {
486: dlp = TAILQ_PREV(dlp, rcs_tqh, l_list);
487: } else if (dlp->l_lineno < start) {
488: ndlp = TAILQ_NEXT(dlp, l_list);
489: if (ndlp->l_lineno > start)
490: break;
491: dlp = ndlp;
492: }
493: }
494:
495: if (dlp == NULL)
496: errx(1, "ed_patch_lines");
497:
498:
499: if (op == 'c') {
1.13 espie 500: insert_after = TAILQ_PREV(dlp, rcs_tqh, l_list);
1.1 joris 501: for (i = 0; i <= (end - start); i++) {
502: ndlp = TAILQ_NEXT(dlp, l_list);
503: TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
504: dlp = ndlp;
505: }
1.13 espie 506: dlp = insert_after;
1.1 joris 507: }
508:
509: if (op == 'a' || op == 'c') {
510: for (;;) {
511: ndlp = lp;
512: lp = TAILQ_NEXT(lp, l_list);
513: if (lp == NULL)
514: errx(1, "ed_patch_lines");
515:
1.17 niallo 516: if (!memcmp(lp->l_line, ".", 1))
1.1 joris 517: break;
518:
519: TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
520: TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
521: lp, l_list);
522: dlp = lp;
523:
524: lp->l_lineno = start;
525: lp = ndlp;
526: }
527: }
528:
529: /*
530: * always resort lines as the markers might be put at the
531: * same line as we first started editing.
532: */
533: lineno = 0;
534: TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
535: sort->l_lineno = lineno++;
536: dlines->l_nblines = lineno - 1;
537: }
538:
539: return (0);
540: }
541:
542: /*
543: * Pick up the line numbers of all changes from one change file.
544: * (This puts the numbers in a vector, which is not strictly necessary,
545: * since the vector is processed in one sequential pass.
546: * The vector could be optimized out of existence)
547: */
548: static size_t
549: readin(char *name, struct diff **dd)
550: {
551: int a, b, c, d;
552: char kind, *p;
553: size_t i;
554:
555: fp[0] = fopen(name, "r");
556: for (i = 0; (p = getchange(fp[0])); i++) {
557: if (i >= szchanges - 1)
558: increase();
559: a = b = number(&p);
560: if (*p == ',') {
561: p++;
562: b = number(&p);
563: }
564: kind = *p++;
565: c = d = number(&p);
566: if (*p==',') {
567: p++;
568: d = number(&p);
569: }
570: if (kind == 'a')
571: a++;
572: if (kind == 'd')
573: c++;
574: b++;
575: d++;
576: (*dd)[i].old.from = a;
577: (*dd)[i].old.to = b;
578: (*dd)[i].new.from = c;
579: (*dd)[i].new.to = d;
580: }
581:
582: if (i) {
583: (*dd)[i].old.from = (*dd)[i-1].old.to;
584: (*dd)[i].new.from = (*dd)[i-1].new.to;
585: }
586: (void)fclose(fp[0]);
587:
588: return (i);
589: }
590:
591: static int
592: number(char **lc)
593: {
594: int nn;
595:
596: nn = 0;
597: while (isdigit((unsigned char)(**lc)))
598: nn = nn*10 + *(*lc)++ - '0';
599:
600: return (nn);
601: }
602:
603: static char *
604: getchange(FILE *b)
605: {
606: char *line;
607:
608: while ((line = getline(b, NULL))) {
609: if (isdigit((unsigned char)line[0]))
610: return (line);
611: }
612:
613: return (NULL);
614: }
615:
616: static char *
617: getline(FILE *b, size_t *n)
618: {
619: char *cp;
620: size_t len;
621: static char *buf;
622: static size_t bufsize;
623:
624: if ((cp = fgetln(b, &len)) == NULL)
625: return (NULL);
626:
627: if (cp[len - 1] != '\n')
628: len++;
629: if (len + 1 > bufsize) {
630: char *newbuf;
631: do {
632: bufsize += 1024;
633: } while (len + 1 > bufsize);
634: newbuf = xrealloc(buf, 1, bufsize);
635: buf = newbuf;
636: }
637: memcpy(buf, cp, len - 1);
638: buf[len - 1] = '\n';
639: buf[len] = '\0';
640: if (n != NULL)
641: *n = len;
642:
643: return (buf);
644: }
645:
646: static int
647: merge(size_t m1, size_t m2)
648: {
649: struct diff *d1, *d2, *d3;
650: int dpl, j, t1, t2;
651:
652: d1 = d13;
653: d2 = d23;
654: j = 0;
655: while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
656: if (debug) {
657: printf("%d,%d=%d,%d %d,%d=%d,%d\n",
658: d1->old.from, d1->old.to,
659: d1->new.from, d1->new.to,
660: d2->old.from, d2->old.to,
661: d2->new.from, d2->new.to);
662: }
663:
664: /* first file is different from others */
665: if (!t2 || (t1 && d1->new.to < d2->new.from)) {
666: /* stuff peculiar to 1st file */
667: if (eflag==0) {
668: separate("1");
669: change(1, &d1->old, 0);
670: keep(2, &d1->new);
671: change(3, &d1->new, 0);
672: }
673: d1++;
674: continue;
675: }
676:
677: /* second file is different from others */
678: if (!t1 || (t2 && d2->new.to < d1->new.from)) {
679: if (eflag==0) {
680: separate("2");
681: keep(1, &d2->new);
682: change(2, &d2->old, 0);
683: change(3, &d2->new, 0);
684: }
685: d2++;
686: continue;
687: }
688:
689: /*
690: * Merge overlapping changes in first file
691: * this happens after extension (see below).
692: */
693: if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {
694: d1[1].old.from = d1->old.from;
695: d1[1].new.from = d1->new.from;
696: d1++;
697: continue;
698: }
699:
700: /* merge overlapping changes in second */
701: if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {
702: d2[1].old.from = d2->old.from;
703: d2[1].new.from = d2->new.from;
704: d2++;
705: continue;
706: }
707: /* stuff peculiar to third file or different in all */
708: if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
709: dpl = duplicate(&d1->old,&d2->old);
710: if (dpl == -1)
711: return (-1);
712:
713: /*
714: * dpl = 0 means all files differ
715: * dpl = 1 means files 1 and 2 identical
716: */
717: if (eflag==0) {
718: separate(dpl ? "3" : "");
719: change(1, &d1->old, dpl);
720: change(2, &d2->old, 0);
721: d3 = d1->old.to > d1->old.from ? d1 : d2;
722: change(3, &d3->new, 0);
723: } else
724: j = edit(d1, dpl, j);
725: d1++;
726: d2++;
727: continue;
728: }
729:
730: /*
731: * Overlapping changes from file 1 and 2; extend changes
732: * appropriately to make them coincide.
733: */
734: if (d1->new.from < d2->new.from) {
735: d2->old.from -= d2->new.from-d1->new.from;
736: d2->new.from = d1->new.from;
737: } else if (d2->new.from < d1->new.from) {
738: d1->old.from -= d1->new.from-d2->new.from;
739: d1->new.from = d2->new.from;
740: }
741: if (d1->new.to > d2->new.to) {
742: d2->old.to += d1->new.to - d2->new.to;
743: d2->new.to = d1->new.to;
744: } else if (d2->new.to > d1->new.to) {
745: d1->old.to += d2->new.to - d1->new.to;
746: d1->new.to = d2->new.to;
747: }
748: }
749:
750: return (edscript(j));
751: }
752:
753: static void
754: separate(const char *s)
755: {
756: diff_output("====%s\n", s);
757: }
758:
759: /*
760: * The range of lines rold.from thru rold.to in file i is to be changed.
761: * It is to be printed only if it does not duplicate something to be
762: * printed later.
763: */
764: static void
765: change(int i, struct range *rold, int fdup)
766: {
767: diff_output("%d:", i);
768: last[i] = rold->to;
769: prange(rold);
770: if (fdup || debug)
771: return;
772: i--;
773: (void)skip(i, rold->from, NULL);
774: (void)skip(i, rold->to, " ");
775: }
776:
777: /*
778: * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
779: */
780: static void
781: prange(struct range *rold)
782: {
783: if (rold->to <= rold->from)
784: diff_output("%da\n", rold->from - 1);
785: else {
786: diff_output("%d", rold->from);
787: if (rold->to > rold->from+1)
788: diff_output(",%d", rold->to - 1);
789: diff_output("c\n");
790: }
791: }
792:
793: /*
794: * No difference was reported by diff between file 1 (or 2) and file 3,
795: * and an artificial dummy difference (trange) must be ginned up to
796: * correspond to the change reported in the other file.
797: */
798: static void
799: keep(int i, struct range *rnew)
800: {
801: int delta;
802: struct range trange;
803:
804: delta = last[3] - last[i];
805: trange.from = rnew->from - delta;
806: trange.to = rnew->to - delta;
807: change(i, &trange, 1);
808: }
809:
810: /*
811: * skip to just before line number from in file "i". If "pr" is non-NULL,
812: * print all skipped stuff with string pr as a prefix.
813: */
814: static int
815: skip(int i, int from, char *pr)
816: {
817: size_t j, n;
818: char *line;
819:
820: for (n = 0; cline[i] < from - 1; n += j) {
821: if ((line = getline(fp[i], &j)) == NULL)
822: return (-1);
823: if (pr != NULL)
824: diff_output("%s%s", pr, line);
825: cline[i]++;
826: }
827: return ((int) n);
828: }
829:
830: /*
831: * Return 1 or 0 according as the old range (in file 1) contains exactly
832: * the same data as the new range (in file 2).
833: */
834: static int
835: duplicate(struct range *r1, struct range *r2)
836: {
837: int c,d;
838: int nchar;
839: int nline;
840:
841: if (r1->to-r1->from != r2->to-r2->from)
842: return (0);
843: (void)skip(0, r1->from, NULL);
844: (void)skip(1, r2->from, NULL);
845: nchar = 0;
846: for (nline=0; nline < r1->to - r1->from; nline++) {
847: do {
848: c = getc(fp[0]);
849: d = getc(fp[1]);
850: if (c == -1 || d== -1)
851: return (-1);
852: nchar++;
853: if (c != d) {
854: repos(nchar);
855: return (0);
856: }
857: } while (c != '\n');
858: }
859: repos(nchar);
860: return (1);
861: }
862:
863: static void
864: repos(int nchar)
865: {
866: int i;
867:
868: for (i = 0; i < 2; i++)
869: (void)fseek(fp[i], (long)-nchar, 1);
870: }
871:
872: /*
873: * collect an editing script for later regurgitation
874: */
875: static int
876: edit(struct diff *diff, int fdup, int j)
877: {
878: if (((fdup + 1) & eflag) == 0)
879: return (j);
880: j++;
881: overlap[j] = !fdup;
882: if (!fdup)
883: overlapcnt++;
884: de[j].old.from = diff->old.from;
885: de[j].old.to = diff->old.to;
886: de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
887: de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
888: return (j);
889: }
890:
891: /* regurgitate */
892: static int
893: edscript(int n)
894: {
895: int j, k;
896: char block[BUFSIZ+1];
897:
898: for (n = n; n > 0; n--) {
899: if (!oflag || !overlap[n])
900: prange(&de[n].old);
901: else
902: diff_output("%da\n=======\n", de[n].old.to -1);
903: (void)fseek(fp[2], (long)de[n].new.from, 0);
904: for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
905: j = k > BUFSIZ ? BUFSIZ : k;
1.8 ray 906: if (fread(block, 1, (size_t)j,
1.1 joris 907: fp[2]) != (size_t)j)
908: return (-1);
909: block[j] = '\0';
910: diff_output("%s", block);
911: }
912:
913: if (!oflag || !overlap[n])
914: diff_output(".\n");
915: else {
916: diff_output("%s\n.\n", f3mark);
917: diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
918: }
919: }
920:
921: return (overlapcnt);
922: }
923:
924: static void
925: increase(void)
926: {
927: struct diff *p;
928: char *q;
929: size_t newsz, incr;
930:
931: /* are the memset(3) calls needed? */
932: newsz = szchanges == 0 ? 64 : 2 * szchanges;
933: incr = newsz - szchanges;
934:
935: p = xrealloc(d13, newsz, sizeof(*d13));
936: memset(p + szchanges, 0, incr * sizeof(*d13));
937: d13 = p;
938: p = xrealloc(d23, newsz, sizeof(*d23));
939: memset(p + szchanges, 0, incr * sizeof(*d23));
940: d23 = p;
941: p = xrealloc(de, newsz, sizeof(*de));
942: memset(p + szchanges, 0, incr * sizeof(*de));
943: de = p;
944: q = xrealloc(overlap, newsz, sizeof(*overlap));
945: memset(q + szchanges, 0, incr * sizeof(*overlap));
946: overlap = q;
947: szchanges = newsz;
948: }
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