1 /* $OpenBSD: diffreg.c,v 1.91 2016/03/01 20:57:35 natano Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-4-Clause
5 *
6 * Copyright (C) Caldera International Inc. 2001-2002.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code and documentation must retain the above
13 * copyright notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed or owned by Caldera
20 * International, Inc.
21 * 4. Neither the name of Caldera International, Inc. nor the names of other
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
26 * INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
30 * INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
34 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
35 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38 /*-
39 * Copyright (c) 1991, 1993
40 * The Regents of the University of California. All rights reserved.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
65 *
66 * @(#)diffreg.c 8.1 (Berkeley) 6/6/93
67 */
68
69 #include <sys/cdefs.h>
70 __FBSDID("$FreeBSD$");
71
72 #include <sys/capsicum.h>
73 #include <sys/stat.h>
74
75 #include <capsicum_helpers.h>
76 #include <ctype.h>
77 #include <err.h>
78 #include <errno.h>
79 #include <fcntl.h>
80 #include <paths.h>
81 #include <regex.h>
82 #include <stdbool.h>
83 #include <stddef.h>
84 #include <stdint.h>
85 #include <stdio.h>
86 #include <stdlib.h>
87 #include <string.h>
88
89 #include "pr.h"
90 #include "diff.h"
91 #include "xmalloc.h"
92
93 /*
94 * diff - compare two files.
95 */
96
97 /*
98 * Uses an algorithm due to Harold Stone, which finds
99 * a pair of longest identical subsequences in the two
100 * files.
101 *
102 * The major goal is to generate the match vector J.
103 * J[i] is the index of the line in file1 corresponding
104 * to line i file0. J[i] = 0 if there is no
105 * such line in file1.
106 *
107 * Lines are hashed so as to work in core. All potential
108 * matches are located by sorting the lines of each file
109 * on the hash (called ``value''). In particular, this
110 * collects the equivalence classes in file1 together.
111 * Subroutine equiv replaces the value of each line in
112 * file0 by the index of the first element of its
113 * matching equivalence in (the reordered) file1.
114 * To save space equiv squeezes file1 into a single
115 * array member in which the equivalence classes
116 * are simply concatenated, except that their first
117 * members are flagged by changing sign.
118 *
119 * Next the indices that point into member are unsorted into
120 * array class according to the original order of file0.
121 *
122 * The cleverness lies in routine stone. This marches
123 * through the lines of file0, developing a vector klist
124 * of "k-candidates". At step i a k-candidate is a matched
125 * pair of lines x,y (x in file0 y in file1) such that
126 * there is a common subsequence of length k
127 * between the first i lines of file0 and the first y
128 * lines of file1, but there is no such subsequence for
129 * any smaller y. x is the earliest possible mate to y
130 * that occurs in such a subsequence.
131 *
132 * Whenever any of the members of the equivalence class of
133 * lines in file1 matable to a line in file0 has serial number
134 * less than the y of some k-candidate, that k-candidate
135 * with the smallest such y is replaced. The new
136 * k-candidate is chained (via pred) to the current
137 * k-1 candidate so that the actual subsequence can
138 * be recovered. When a member has serial number greater
139 * that the y of all k-candidates, the klist is extended.
140 * At the end, the longest subsequence is pulled out
141 * and placed in the array J by unravel
142 *
143 * With J in hand, the matches there recorded are
144 * check'ed against reality to assure that no spurious
145 * matches have crept in due to hashing. If they have,
146 * they are broken, and "jackpot" is recorded--a harmless
147 * matter except that a true match for a spuriously
148 * mated line may now be unnecessarily reported as a change.
149 *
150 * Much of the complexity of the program comes simply
151 * from trying to minimize core utilization and
152 * maximize the range of doable problems by dynamically
153 * allocating what is needed and reusing what is not.
154 * The core requirements for problems larger than somewhat
155 * are (in words) 2*length(file0) + length(file1) +
156 * 3*(number of k-candidates installed), typically about
157 * 6n words for files of length n.
158 */
159
160 struct cand {
161 int x;
162 int y;
163 int pred;
164 };
165
166 static struct line {
167 int serial;
168 int value;
169 } *file[2];
170
171 /*
172 * The following struct is used to record change information when
173 * doing a "context" or "unified" diff. (see routine "change" to
174 * understand the highly mnemonic field names)
175 */
176 struct context_vec {
177 int a; /* start line in old file */
178 int b; /* end line in old file */
179 int c; /* start line in new file */
180 int d; /* end line in new file */
181 };
182
183 #define diff_output printf
184 static FILE *opentemp(const char *);
185 static void output(char *, FILE *, char *, FILE *, int);
186 static void check(FILE *, FILE *, int);
187 static void range(int, int, const char *);
188 static void uni_range(int, int);
189 static void dump_context_vec(FILE *, FILE *, int);
190 static void dump_unified_vec(FILE *, FILE *, int);
191 static void prepare(int, FILE *, size_t, int);
192 static void prune(void);
193 static void equiv(struct line *, int, struct line *, int, int *);
194 static void unravel(int);
195 static void unsort(struct line *, int, int *);
196 static void change(char *, FILE *, char *, FILE *, int, int, int, int, int *);
197 static void sort(struct line *, int);
198 static void print_header(const char *, const char *);
199 static bool ignoreline_pattern(char *);
200 static bool ignoreline(char *, bool);
201 static int asciifile(FILE *);
202 static int fetch(long *, int, int, FILE *, int, int, int);
203 static int newcand(int, int, int);
204 static int search(int *, int, int);
205 static int skipline(FILE *);
206 static int isqrt(int);
207 static int stone(int *, int, int *, int *, int);
208 static int readhash(FILE *, int);
209 static int files_differ(FILE *, FILE *, int);
210 static char *match_function(const long *, int, FILE *);
211 static char *preadline(int, size_t, off_t);
212
213 static int *J; /* will be overlaid on class */
214 static int *class; /* will be overlaid on file[0] */
215 static int *klist; /* will be overlaid on file[0] after class */
216 static int *member; /* will be overlaid on file[1] */
217 static int clen;
218 static int inifdef; /* whether or not we are in a #ifdef block */
219 static int len[2];
220 static int pref, suff; /* length of prefix and suffix */
221 static int slen[2];
222 static int anychange;
223 static long *ixnew; /* will be overlaid on file[1] */
224 static long *ixold; /* will be overlaid on klist */
225 static struct cand *clist; /* merely a free storage pot for candidates */
226 static int clistlen; /* the length of clist */
227 static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
228 static int (*chrtran)(int); /* translation table for case-folding */
229 static struct context_vec *context_vec_start;
230 static struct context_vec *context_vec_end;
231 static struct context_vec *context_vec_ptr;
232
233 #define FUNCTION_CONTEXT_SIZE 55
234 static char lastbuf[FUNCTION_CONTEXT_SIZE];
235 static int lastline;
236 static int lastmatchline;
237
238 static int
clow2low(int c)239 clow2low(int c)
240 {
241
242 return (c);
243 }
244
245 static int
cup2low(int c)246 cup2low(int c)
247 {
248
249 return tolower(c);
250 }
251
252 int
diffreg(char * file1,char * file2,int flags,int capsicum)253 diffreg(char *file1, char *file2, int flags, int capsicum)
254 {
255 FILE *f1, *f2;
256 int i, rval;
257 struct pr *pr = NULL;
258 cap_rights_t rights_ro;
259
260 f1 = f2 = NULL;
261 rval = D_SAME;
262 anychange = 0;
263 lastline = 0;
264 lastmatchline = 0;
265 context_vec_ptr = context_vec_start - 1;
266 if (flags & D_IGNORECASE)
267 chrtran = cup2low;
268 else
269 chrtran = clow2low;
270 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
271 return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
272 if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0)
273 goto closem;
274
275 if (flags & D_EMPTY1)
276 f1 = fopen(_PATH_DEVNULL, "r");
277 else {
278 if (!S_ISREG(stb1.st_mode)) {
279 if ((f1 = opentemp(file1)) == NULL ||
280 fstat(fileno(f1), &stb1) < 0) {
281 warn("%s", file1);
282 status |= 2;
283 goto closem;
284 }
285 } else if (strcmp(file1, "-") == 0)
286 f1 = stdin;
287 else
288 f1 = fopen(file1, "r");
289 }
290 if (f1 == NULL) {
291 warn("%s", file1);
292 status |= 2;
293 goto closem;
294 }
295
296 if (flags & D_EMPTY2)
297 f2 = fopen(_PATH_DEVNULL, "r");
298 else {
299 if (!S_ISREG(stb2.st_mode)) {
300 if ((f2 = opentemp(file2)) == NULL ||
301 fstat(fileno(f2), &stb2) < 0) {
302 warn("%s", file2);
303 status |= 2;
304 goto closem;
305 }
306 } else if (strcmp(file2, "-") == 0)
307 f2 = stdin;
308 else
309 f2 = fopen(file2, "r");
310 }
311 if (f2 == NULL) {
312 warn("%s", file2);
313 status |= 2;
314 goto closem;
315 }
316
317 if (lflag)
318 pr = start_pr(file1, file2);
319
320 if (capsicum) {
321 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
322 if (cap_rights_limit(fileno(f1), &rights_ro) < 0
323 && errno != ENOSYS)
324 err(2, "unable to limit rights on: %s", file1);
325 if (cap_rights_limit(fileno(f2), &rights_ro) < 0 &&
326 errno != ENOSYS)
327 err(2, "unable to limit rights on: %s", file2);
328 if (fileno(f1) == STDIN_FILENO || fileno(f2) == STDIN_FILENO) {
329 /* stding has already been limited */
330 if (caph_limit_stderr() == -1)
331 err(2, "unable to limit stderr");
332 if (caph_limit_stdout() == -1)
333 err(2, "unable to limit stdout");
334 } else if (caph_limit_stdio() == -1)
335 err(2, "unable to limit stdio");
336
337 caph_cache_catpages();
338 caph_cache_tzdata();
339 if (caph_enter() < 0)
340 err(2, "unable to enter capability mode");
341 }
342
343 switch (files_differ(f1, f2, flags)) {
344 case 0:
345 goto closem;
346 case 1:
347 break;
348 default:
349 /* error */
350 status |= 2;
351 goto closem;
352 }
353
354 if ((flags & D_FORCEASCII) == 0 &&
355 (!asciifile(f1) || !asciifile(f2))) {
356 rval = D_BINARY;
357 status |= 1;
358 goto closem;
359 }
360 prepare(0, f1, stb1.st_size, flags);
361 prepare(1, f2, stb2.st_size, flags);
362
363 prune();
364 sort(sfile[0], slen[0]);
365 sort(sfile[1], slen[1]);
366
367 member = (int *)file[1];
368 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
369 member = xreallocarray(member, slen[1] + 2, sizeof(*member));
370
371 class = (int *)file[0];
372 unsort(sfile[0], slen[0], class);
373 class = xreallocarray(class, slen[0] + 2, sizeof(*class));
374
375 klist = xcalloc(slen[0] + 2, sizeof(*klist));
376 clen = 0;
377 clistlen = 100;
378 clist = xcalloc(clistlen, sizeof(*clist));
379 i = stone(class, slen[0], member, klist, flags);
380 free(member);
381 free(class);
382
383 J = xreallocarray(J, len[0] + 2, sizeof(*J));
384 unravel(klist[i]);
385 free(clist);
386 free(klist);
387
388 ixold = xreallocarray(ixold, len[0] + 2, sizeof(*ixold));
389 ixnew = xreallocarray(ixnew, len[1] + 2, sizeof(*ixnew));
390 check(f1, f2, flags);
391 output(file1, f1, file2, f2, flags);
392 if (pr != NULL)
393 stop_pr(pr);
394
395 closem:
396 if (anychange) {
397 status |= 1;
398 if (rval == D_SAME)
399 rval = D_DIFFER;
400 }
401 if (f1 != NULL)
402 fclose(f1);
403 if (f2 != NULL)
404 fclose(f2);
405
406 return (rval);
407 }
408
409 /*
410 * Check to see if the given files differ.
411 * Returns 0 if they are the same, 1 if different, and -1 on error.
412 * XXX - could use code from cmp(1) [faster]
413 */
414 static int
files_differ(FILE * f1,FILE * f2,int flags)415 files_differ(FILE *f1, FILE *f2, int flags)
416 {
417 char buf1[BUFSIZ], buf2[BUFSIZ];
418 size_t i, j;
419
420 if ((flags & (D_EMPTY1|D_EMPTY2)) || stb1.st_size != stb2.st_size ||
421 (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT))
422 return (1);
423 for (;;) {
424 i = fread(buf1, 1, sizeof(buf1), f1);
425 j = fread(buf2, 1, sizeof(buf2), f2);
426 if ((!i && ferror(f1)) || (!j && ferror(f2)))
427 return (-1);
428 if (i != j)
429 return (1);
430 if (i == 0)
431 return (0);
432 if (memcmp(buf1, buf2, i) != 0)
433 return (1);
434 }
435 }
436
437 static FILE *
opentemp(const char * f)438 opentemp(const char *f)
439 {
440 char buf[BUFSIZ], tempfile[PATH_MAX];
441 ssize_t nread;
442 int ifd, ofd;
443
444 if (strcmp(f, "-") == 0)
445 ifd = STDIN_FILENO;
446 else if ((ifd = open(f, O_RDONLY, 0644)) < 0)
447 return (NULL);
448
449 (void)strlcpy(tempfile, _PATH_TMP "/diff.XXXXXXXX", sizeof(tempfile));
450
451 if ((ofd = mkstemp(tempfile)) < 0) {
452 close(ifd);
453 return (NULL);
454 }
455 unlink(tempfile);
456 while ((nread = read(ifd, buf, BUFSIZ)) > 0) {
457 if (write(ofd, buf, nread) != nread) {
458 close(ifd);
459 close(ofd);
460 return (NULL);
461 }
462 }
463 close(ifd);
464 lseek(ofd, (off_t)0, SEEK_SET);
465 return (fdopen(ofd, "r"));
466 }
467
468 char *
splice(char * dir,char * path)469 splice(char *dir, char *path)
470 {
471 char *tail, *buf;
472 size_t dirlen;
473
474 dirlen = strlen(dir);
475 while (dirlen != 0 && dir[dirlen - 1] == '/')
476 dirlen--;
477 if ((tail = strrchr(path, '/')) == NULL)
478 tail = path;
479 else
480 tail++;
481 xasprintf(&buf, "%.*s/%s", (int)dirlen, dir, tail);
482 return (buf);
483 }
484
485 static void
prepare(int i,FILE * fd,size_t filesize,int flags)486 prepare(int i, FILE *fd, size_t filesize, int flags)
487 {
488 struct line *p;
489 int h;
490 size_t sz, j;
491
492 rewind(fd);
493
494 sz = MIN(filesize, SIZE_MAX) / 25;
495 if (sz < 100)
496 sz = 100;
497
498 p = xcalloc(sz + 3, sizeof(*p));
499 for (j = 0; (h = readhash(fd, flags));) {
500 if (j == sz) {
501 sz = sz * 3 / 2;
502 p = xreallocarray(p, sz + 3, sizeof(*p));
503 }
504 p[++j].value = h;
505 }
506 len[i] = j;
507 file[i] = p;
508 }
509
510 static void
prune(void)511 prune(void)
512 {
513 int i, j;
514
515 for (pref = 0; pref < len[0] && pref < len[1] &&
516 file[0][pref + 1].value == file[1][pref + 1].value;
517 pref++)
518 ;
519 for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
520 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
521 suff++)
522 ;
523 for (j = 0; j < 2; j++) {
524 sfile[j] = file[j] + pref;
525 slen[j] = len[j] - pref - suff;
526 for (i = 0; i <= slen[j]; i++)
527 sfile[j][i].serial = i;
528 }
529 }
530
531 static void
equiv(struct line * a,int n,struct line * b,int m,int * c)532 equiv(struct line *a, int n, struct line *b, int m, int *c)
533 {
534 int i, j;
535
536 i = j = 1;
537 while (i <= n && j <= m) {
538 if (a[i].value < b[j].value)
539 a[i++].value = 0;
540 else if (a[i].value == b[j].value)
541 a[i++].value = j;
542 else
543 j++;
544 }
545 while (i <= n)
546 a[i++].value = 0;
547 b[m + 1].value = 0;
548 j = 0;
549 while (++j <= m) {
550 c[j] = -b[j].serial;
551 while (b[j + 1].value == b[j].value) {
552 j++;
553 c[j] = b[j].serial;
554 }
555 }
556 c[j] = -1;
557 }
558
559 /* Code taken from ping.c */
560 static int
isqrt(int n)561 isqrt(int n)
562 {
563 int y, x = 1;
564
565 if (n == 0)
566 return (0);
567
568 do { /* newton was a stinker */
569 y = x;
570 x = n / x;
571 x += y;
572 x /= 2;
573 } while ((x - y) > 1 || (x - y) < -1);
574
575 return (x);
576 }
577
578 static int
stone(int * a,int n,int * b,int * c,int flags)579 stone(int *a, int n, int *b, int *c, int flags)
580 {
581 int i, k, y, j, l;
582 int oldc, tc, oldl, sq;
583 u_int numtries, bound;
584
585 if (flags & D_MINIMAL)
586 bound = UINT_MAX;
587 else {
588 sq = isqrt(n);
589 bound = MAX(256, sq);
590 }
591
592 k = 0;
593 c[0] = newcand(0, 0, 0);
594 for (i = 1; i <= n; i++) {
595 j = a[i];
596 if (j == 0)
597 continue;
598 y = -b[j];
599 oldl = 0;
600 oldc = c[0];
601 numtries = 0;
602 do {
603 if (y <= clist[oldc].y)
604 continue;
605 l = search(c, k, y);
606 if (l != oldl + 1)
607 oldc = c[l - 1];
608 if (l <= k) {
609 if (clist[c[l]].y <= y)
610 continue;
611 tc = c[l];
612 c[l] = newcand(i, y, oldc);
613 oldc = tc;
614 oldl = l;
615 numtries++;
616 } else {
617 c[l] = newcand(i, y, oldc);
618 k++;
619 break;
620 }
621 } while ((y = b[++j]) > 0 && numtries < bound);
622 }
623 return (k);
624 }
625
626 static int
newcand(int x,int y,int pred)627 newcand(int x, int y, int pred)
628 {
629 struct cand *q;
630
631 if (clen == clistlen) {
632 clistlen = clistlen * 11 / 10;
633 clist = xreallocarray(clist, clistlen, sizeof(*clist));
634 }
635 q = clist + clen;
636 q->x = x;
637 q->y = y;
638 q->pred = pred;
639 return (clen++);
640 }
641
642 static int
search(int * c,int k,int y)643 search(int *c, int k, int y)
644 {
645 int i, j, l, t;
646
647 if (clist[c[k]].y < y) /* quick look for typical case */
648 return (k + 1);
649 i = 0;
650 j = k + 1;
651 for (;;) {
652 l = (i + j) / 2;
653 if (l <= i)
654 break;
655 t = clist[c[l]].y;
656 if (t > y)
657 j = l;
658 else if (t < y)
659 i = l;
660 else
661 return (l);
662 }
663 return (l + 1);
664 }
665
666 static void
unravel(int p)667 unravel(int p)
668 {
669 struct cand *q;
670 int i;
671
672 for (i = 0; i <= len[0]; i++)
673 J[i] = i <= pref ? i :
674 i > len[0] - suff ? i + len[1] - len[0] : 0;
675 for (q = clist + p; q->y != 0; q = clist + q->pred)
676 J[q->x + pref] = q->y + pref;
677 }
678
679 /*
680 * Check does double duty:
681 * 1. ferret out any fortuitous correspondences due
682 * to confounding by hashing (which result in "jackpot")
683 * 2. collect random access indexes to the two files
684 */
685 static void
check(FILE * f1,FILE * f2,int flags)686 check(FILE *f1, FILE *f2, int flags)
687 {
688 int i, j, jackpot, c, d;
689 long ctold, ctnew;
690
691 rewind(f1);
692 rewind(f2);
693 j = 1;
694 ixold[0] = ixnew[0] = 0;
695 jackpot = 0;
696 ctold = ctnew = 0;
697 for (i = 1; i <= len[0]; i++) {
698 if (J[i] == 0) {
699 ixold[i] = ctold += skipline(f1);
700 continue;
701 }
702 while (j < J[i]) {
703 ixnew[j] = ctnew += skipline(f2);
704 j++;
705 }
706 if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS|D_IGNORECASE|D_STRIPCR)) {
707 for (;;) {
708 c = getc(f1);
709 d = getc(f2);
710 /*
711 * GNU diff ignores a missing newline
712 * in one file for -b or -w.
713 */
714 if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) {
715 if (c == EOF && d == '\n') {
716 ctnew++;
717 break;
718 } else if (c == '\n' && d == EOF) {
719 ctold++;
720 break;
721 }
722 }
723 ctold++;
724 ctnew++;
725 if (flags & D_STRIPCR && (c == '\r' || d == '\r')) {
726 if (c == '\r') {
727 if ((c = getc(f1)) == '\n') {
728 ctold++;
729 } else {
730 ungetc(c, f1);
731 }
732 }
733 if (d == '\r') {
734 if ((d = getc(f2)) == '\n') {
735 ctnew++;
736 } else {
737 ungetc(d, f2);
738 }
739 }
740 break;
741 }
742 if ((flags & D_FOLDBLANKS) && isspace(c) &&
743 isspace(d)) {
744 do {
745 if (c == '\n')
746 break;
747 ctold++;
748 } while (isspace(c = getc(f1)));
749 do {
750 if (d == '\n')
751 break;
752 ctnew++;
753 } while (isspace(d = getc(f2)));
754 } else if ((flags & D_IGNOREBLANKS)) {
755 while (isspace(c) && c != '\n') {
756 c = getc(f1);
757 ctold++;
758 }
759 while (isspace(d) && d != '\n') {
760 d = getc(f2);
761 ctnew++;
762 }
763 }
764 if (chrtran(c) != chrtran(d)) {
765 jackpot++;
766 J[i] = 0;
767 if (c != '\n' && c != EOF)
768 ctold += skipline(f1);
769 if (d != '\n' && c != EOF)
770 ctnew += skipline(f2);
771 break;
772 }
773 if (c == '\n' || c == EOF)
774 break;
775 }
776 } else {
777 for (;;) {
778 ctold++;
779 ctnew++;
780 if ((c = getc(f1)) != (d = getc(f2))) {
781 /* jackpot++; */
782 J[i] = 0;
783 if (c != '\n' && c != EOF)
784 ctold += skipline(f1);
785 if (d != '\n' && c != EOF)
786 ctnew += skipline(f2);
787 break;
788 }
789 if (c == '\n' || c == EOF)
790 break;
791 }
792 }
793 ixold[i] = ctold;
794 ixnew[j] = ctnew;
795 j++;
796 }
797 for (; j <= len[1]; j++) {
798 ixnew[j] = ctnew += skipline(f2);
799 }
800 /*
801 * if (jackpot)
802 * fprintf(stderr, "jackpot\n");
803 */
804 }
805
806 /* shellsort CACM #201 */
807 static void
sort(struct line * a,int n)808 sort(struct line *a, int n)
809 {
810 struct line *ai, *aim, w;
811 int j, m = 0, k;
812
813 if (n == 0)
814 return;
815 for (j = 1; j <= n; j *= 2)
816 m = 2 * j - 1;
817 for (m /= 2; m != 0; m /= 2) {
818 k = n - m;
819 for (j = 1; j <= k; j++) {
820 for (ai = &a[j]; ai > a; ai -= m) {
821 aim = &ai[m];
822 if (aim < ai)
823 break; /* wraparound */
824 if (aim->value > ai[0].value ||
825 (aim->value == ai[0].value &&
826 aim->serial > ai[0].serial))
827 break;
828 w.value = ai[0].value;
829 ai[0].value = aim->value;
830 aim->value = w.value;
831 w.serial = ai[0].serial;
832 ai[0].serial = aim->serial;
833 aim->serial = w.serial;
834 }
835 }
836 }
837 }
838
839 static void
unsort(struct line * f,int l,int * b)840 unsort(struct line *f, int l, int *b)
841 {
842 int *a, i;
843
844 a = xcalloc(l + 1, sizeof(*a));
845 for (i = 1; i <= l; i++)
846 a[f[i].serial] = f[i].value;
847 for (i = 1; i <= l; i++)
848 b[i] = a[i];
849 free(a);
850 }
851
852 static int
skipline(FILE * f)853 skipline(FILE *f)
854 {
855 int i, c;
856
857 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
858 continue;
859 return (i);
860 }
861
862 static void
output(char * file1,FILE * f1,char * file2,FILE * f2,int flags)863 output(char *file1, FILE *f1, char *file2, FILE *f2, int flags)
864 {
865 int m, i0, i1, j0, j1;
866
867 rewind(f1);
868 rewind(f2);
869 m = len[0];
870 J[0] = 0;
871 J[m + 1] = len[1] + 1;
872 if (diff_format != D_EDIT) {
873 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
874 while (i0 <= m && J[i0] == J[i0 - 1] + 1)
875 i0++;
876 j0 = J[i0 - 1] + 1;
877 i1 = i0 - 1;
878 while (i1 < m && J[i1 + 1] == 0)
879 i1++;
880 j1 = J[i1 + 1] - 1;
881 J[i1] = j1;
882 change(file1, f1, file2, f2, i0, i1, j0, j1, &flags);
883 }
884 } else {
885 for (i0 = m; i0 >= 1; i0 = i1 - 1) {
886 while (i0 >= 1 && J[i0] == J[i0 + 1] - 1 && J[i0] != 0)
887 i0--;
888 j0 = J[i0 + 1] - 1;
889 i1 = i0 + 1;
890 while (i1 > 1 && J[i1 - 1] == 0)
891 i1--;
892 j1 = J[i1 - 1] + 1;
893 J[i1] = j1;
894 change(file1, f1, file2, f2, i1, i0, j1, j0, &flags);
895 }
896 }
897 if (m == 0)
898 change(file1, f1, file2, f2, 1, 0, 1, len[1], &flags);
899 if (diff_format == D_IFDEF || diff_format == D_GFORMAT) {
900 for (;;) {
901 #define c i0
902 if ((c = getc(f1)) == EOF)
903 return;
904 diff_output("%c", c);
905 }
906 #undef c
907 }
908 if (anychange != 0) {
909 if (diff_format == D_CONTEXT)
910 dump_context_vec(f1, f2, flags);
911 else if (diff_format == D_UNIFIED)
912 dump_unified_vec(f1, f2, flags);
913 }
914 }
915
916 static void
range(int a,int b,const char * separator)917 range(int a, int b, const char *separator)
918 {
919 diff_output("%d", a > b ? b : a);
920 if (a < b)
921 diff_output("%s%d", separator, b);
922 }
923
924 static void
uni_range(int a,int b)925 uni_range(int a, int b)
926 {
927 if (a < b)
928 diff_output("%d,%d", a, b - a + 1);
929 else if (a == b)
930 diff_output("%d", b);
931 else
932 diff_output("%d,0", b);
933 }
934
935 static char *
preadline(int fd,size_t rlen,off_t off)936 preadline(int fd, size_t rlen, off_t off)
937 {
938 char *line;
939 ssize_t nr;
940
941 line = xmalloc(rlen + 1);
942 if ((nr = pread(fd, line, rlen, off)) < 0)
943 err(2, "preadline");
944 if (nr > 0 && line[nr-1] == '\n')
945 nr--;
946 line[nr] = '\0';
947 return (line);
948 }
949
950 static bool
ignoreline_pattern(char * line)951 ignoreline_pattern(char *line)
952 {
953 int ret;
954
955 ret = regexec(&ignore_re, line, 0, NULL, 0);
956 free(line);
957 return (ret == 0); /* if it matched, it should be ignored. */
958 }
959
960 static bool
ignoreline(char * line,bool skip_blanks)961 ignoreline(char *line, bool skip_blanks)
962 {
963
964 if (ignore_pats != NULL && skip_blanks)
965 return (ignoreline_pattern(line) || *line == '\0');
966 if (ignore_pats != NULL)
967 return (ignoreline_pattern(line));
968 if (skip_blanks)
969 return (*line == '\0');
970 /* No ignore criteria specified */
971 return (false);
972 }
973
974 /*
975 * Indicate that there is a difference between lines a and b of the from file
976 * to get to lines c to d of the to file. If a is greater then b then there
977 * are no lines in the from file involved and this means that there were
978 * lines appended (beginning at b). If c is greater than d then there are
979 * lines missing from the to file.
980 */
981 static void
change(char * file1,FILE * f1,char * file2,FILE * f2,int a,int b,int c,int d,int * pflags)982 change(char *file1, FILE *f1, char *file2, FILE *f2, int a, int b, int c, int d,
983 int *pflags)
984 {
985 static size_t max_context = 64;
986 long curpos;
987 int i, nc, f;
988 const char *walk;
989 bool skip_blanks;
990
991 skip_blanks = (*pflags & D_SKIPBLANKLINES);
992 restart:
993 if ((diff_format != D_IFDEF || diff_format == D_GFORMAT) &&
994 a > b && c > d)
995 return;
996 if (ignore_pats != NULL || skip_blanks) {
997 char *line;
998 /*
999 * All lines in the change, insert, or delete must
1000 * match an ignore pattern for the change to be
1001 * ignored.
1002 */
1003 if (a <= b) { /* Changes and deletes. */
1004 for (i = a; i <= b; i++) {
1005 line = preadline(fileno(f1),
1006 ixold[i] - ixold[i - 1], ixold[i - 1]);
1007 if (!ignoreline(line, skip_blanks))
1008 goto proceed;
1009 }
1010 }
1011 if (a > b || c <= d) { /* Changes and inserts. */
1012 for (i = c; i <= d; i++) {
1013 line = preadline(fileno(f2),
1014 ixnew[i] - ixnew[i - 1], ixnew[i - 1]);
1015 if (!ignoreline(line, skip_blanks))
1016 goto proceed;
1017 }
1018 }
1019 return;
1020 }
1021 proceed:
1022 if (*pflags & D_HEADER && diff_format != D_BRIEF) {
1023 diff_output("%s %s %s\n", diffargs, file1, file2);
1024 *pflags &= ~D_HEADER;
1025 }
1026 if (diff_format == D_CONTEXT || diff_format == D_UNIFIED) {
1027 /*
1028 * Allocate change records as needed.
1029 */
1030 if (context_vec_ptr == context_vec_end - 1) {
1031 ptrdiff_t offset = context_vec_ptr - context_vec_start;
1032 max_context <<= 1;
1033 context_vec_start = xreallocarray(context_vec_start,
1034 max_context, sizeof(*context_vec_start));
1035 context_vec_end = context_vec_start + max_context;
1036 context_vec_ptr = context_vec_start + offset;
1037 }
1038 if (anychange == 0) {
1039 /*
1040 * Print the context/unidiff header first time through.
1041 */
1042 print_header(file1, file2);
1043 anychange = 1;
1044 } else if (a > context_vec_ptr->b + (2 * diff_context) + 1 &&
1045 c > context_vec_ptr->d + (2 * diff_context) + 1) {
1046 /*
1047 * If this change is more than 'diff_context' lines from the
1048 * previous change, dump the record and reset it.
1049 */
1050 if (diff_format == D_CONTEXT)
1051 dump_context_vec(f1, f2, *pflags);
1052 else
1053 dump_unified_vec(f1, f2, *pflags);
1054 }
1055 context_vec_ptr++;
1056 context_vec_ptr->a = a;
1057 context_vec_ptr->b = b;
1058 context_vec_ptr->c = c;
1059 context_vec_ptr->d = d;
1060 return;
1061 }
1062 if (anychange == 0)
1063 anychange = 1;
1064 switch (diff_format) {
1065 case D_BRIEF:
1066 return;
1067 case D_NORMAL:
1068 case D_EDIT:
1069 range(a, b, ",");
1070 diff_output("%c", a > b ? 'a' : c > d ? 'd' : 'c');
1071 if (diff_format == D_NORMAL)
1072 range(c, d, ",");
1073 diff_output("\n");
1074 break;
1075 case D_REVERSE:
1076 diff_output("%c", a > b ? 'a' : c > d ? 'd' : 'c');
1077 range(a, b, " ");
1078 diff_output("\n");
1079 break;
1080 case D_NREVERSE:
1081 if (a > b)
1082 diff_output("a%d %d\n", b, d - c + 1);
1083 else {
1084 diff_output("d%d %d\n", a, b - a + 1);
1085 if (!(c > d))
1086 /* add changed lines */
1087 diff_output("a%d %d\n", b, d - c + 1);
1088 }
1089 break;
1090 }
1091 if (diff_format == D_GFORMAT) {
1092 curpos = ftell(f1);
1093 /* print through if append (a>b), else to (nb: 0 vs 1 orig) */
1094 nc = ixold[a > b ? b : a - 1] - curpos;
1095 for (i = 0; i < nc; i++)
1096 diff_output("%c", getc(f1));
1097 for (walk = group_format; *walk != '\0'; walk++) {
1098 if (*walk == '%') {
1099 walk++;
1100 switch (*walk) {
1101 case '<':
1102 fetch(ixold, a, b, f1, '<', 1, *pflags);
1103 break;
1104 case '>':
1105 fetch(ixnew, c, d, f2, '>', 0, *pflags);
1106 break;
1107 default:
1108 diff_output("%%%c", *walk);
1109 break;
1110 }
1111 continue;
1112 }
1113 diff_output("%c", *walk);
1114 }
1115 }
1116 if (diff_format == D_NORMAL || diff_format == D_IFDEF) {
1117 fetch(ixold, a, b, f1, '<', 1, *pflags);
1118 if (a <= b && c <= d && diff_format == D_NORMAL)
1119 diff_output("---\n");
1120 }
1121 f = 0;
1122 if (diff_format != D_GFORMAT)
1123 f = fetch(ixnew, c, d, f2, diff_format == D_NORMAL ? '>' : '\0', 0, *pflags);
1124 if (f != 0 && diff_format == D_EDIT) {
1125 /*
1126 * A non-zero return value for D_EDIT indicates that the
1127 * last line printed was a bare dot (".") that has been
1128 * escaped as ".." to prevent ed(1) from misinterpreting
1129 * it. We have to add a substitute command to change this
1130 * back and restart where we left off.
1131 */
1132 diff_output(".\n");
1133 diff_output("%ds/.//\n", a + f - 1);
1134 b = a + f - 1;
1135 a = b + 1;
1136 c += f;
1137 goto restart;
1138 }
1139 if ((diff_format == D_EDIT || diff_format == D_REVERSE) && c <= d)
1140 diff_output(".\n");
1141 if (inifdef) {
1142 diff_output("#endif /* %s */\n", ifdefname);
1143 inifdef = 0;
1144 }
1145 }
1146
1147 static int
fetch(long * f,int a,int b,FILE * lb,int ch,int oldfile,int flags)1148 fetch(long *f, int a, int b, FILE *lb, int ch, int oldfile, int flags)
1149 {
1150 int i, j, c, lastc, col, nc;
1151 int newcol;
1152
1153 /*
1154 * When doing #ifdef's, copy down to current line
1155 * if this is the first file, so that stuff makes it to output.
1156 */
1157 if ((diff_format == D_IFDEF) && oldfile) {
1158 long curpos = ftell(lb);
1159 /* print through if append (a>b), else to (nb: 0 vs 1 orig) */
1160 nc = f[a > b ? b : a - 1] - curpos;
1161 for (i = 0; i < nc; i++)
1162 diff_output("%c", getc(lb));
1163 }
1164 if (a > b)
1165 return (0);
1166 if (diff_format == D_IFDEF) {
1167 if (inifdef) {
1168 diff_output("#else /* %s%s */\n",
1169 oldfile == 1 ? "!" : "", ifdefname);
1170 } else {
1171 if (oldfile)
1172 diff_output("#ifndef %s\n", ifdefname);
1173 else
1174 diff_output("#ifdef %s\n", ifdefname);
1175 }
1176 inifdef = 1 + oldfile;
1177 }
1178 for (i = a; i <= b; i++) {
1179 fseek(lb, f[i - 1], SEEK_SET);
1180 nc = f[i] - f[i - 1];
1181 if ((diff_format != D_IFDEF && diff_format != D_GFORMAT) &&
1182 ch != '\0') {
1183 diff_output("%c", ch);
1184 if (Tflag && (diff_format == D_NORMAL || diff_format == D_CONTEXT
1185 || diff_format == D_UNIFIED))
1186 diff_output("\t");
1187 else if (diff_format != D_UNIFIED)
1188 diff_output(" ");
1189 }
1190 col = 0;
1191 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
1192 if ((c = getc(lb)) == EOF) {
1193 if (diff_format == D_EDIT || diff_format == D_REVERSE ||
1194 diff_format == D_NREVERSE)
1195 warnx("No newline at end of file");
1196 else
1197 diff_output("\n\\ No newline at end of "
1198 "file\n");
1199 return (0);
1200 }
1201 if (c == '\t' && (flags & D_EXPANDTABS)) {
1202 newcol = ((col/tabsize)+1)*tabsize;
1203 do {
1204 diff_output(" ");
1205 } while (++col < newcol);
1206 } else {
1207 if (diff_format == D_EDIT && j == 1 && c == '\n'
1208 && lastc == '.') {
1209 /*
1210 * Don't print a bare "." line
1211 * since that will confuse ed(1).
1212 * Print ".." instead and return,
1213 * giving the caller an offset
1214 * from which to restart.
1215 */
1216 diff_output(".\n");
1217 return (i - a + 1);
1218 }
1219 diff_output("%c", c);
1220 col++;
1221 }
1222 }
1223 }
1224 return (0);
1225 }
1226
1227 /*
1228 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
1229 */
1230 static int
readhash(FILE * f,int flags)1231 readhash(FILE *f, int flags)
1232 {
1233 int i, t, space;
1234 int sum;
1235
1236 sum = 1;
1237 space = 0;
1238 if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) == 0) {
1239 if (flags & D_IGNORECASE)
1240 for (i = 0; (t = getc(f)) != '\n'; i++) {
1241 if (flags & D_STRIPCR && t == '\r') {
1242 t = getc(f);
1243 if (t == '\n')
1244 break;
1245 ungetc(t, f);
1246 }
1247 if (t == EOF) {
1248 if (i == 0)
1249 return (0);
1250 break;
1251 }
1252 sum = sum * 127 + chrtran(t);
1253 }
1254 else
1255 for (i = 0; (t = getc(f)) != '\n'; i++) {
1256 if (flags & D_STRIPCR && t == '\r') {
1257 t = getc(f);
1258 if (t == '\n')
1259 break;
1260 ungetc(t, f);
1261 }
1262 if (t == EOF) {
1263 if (i == 0)
1264 return (0);
1265 break;
1266 }
1267 sum = sum * 127 + t;
1268 }
1269 } else {
1270 for (i = 0;;) {
1271 switch (t = getc(f)) {
1272 case '\r':
1273 case '\t':
1274 case '\v':
1275 case '\f':
1276 case ' ':
1277 space++;
1278 continue;
1279 default:
1280 if (space && (flags & D_IGNOREBLANKS) == 0) {
1281 i++;
1282 space = 0;
1283 }
1284 sum = sum * 127 + chrtran(t);
1285 i++;
1286 continue;
1287 case EOF:
1288 if (i == 0)
1289 return (0);
1290 /* FALLTHROUGH */
1291 case '\n':
1292 break;
1293 }
1294 break;
1295 }
1296 }
1297 /*
1298 * There is a remote possibility that we end up with a zero sum.
1299 * Zero is used as an EOF marker, so return 1 instead.
1300 */
1301 return (sum == 0 ? 1 : sum);
1302 }
1303
1304 static int
asciifile(FILE * f)1305 asciifile(FILE *f)
1306 {
1307 unsigned char buf[BUFSIZ];
1308 size_t cnt;
1309
1310 if (f == NULL)
1311 return (1);
1312
1313 rewind(f);
1314 cnt = fread(buf, 1, sizeof(buf), f);
1315 return (memchr(buf, '\0', cnt) == NULL);
1316 }
1317
1318 #define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0)
1319
1320 static char *
match_function(const long * f,int pos,FILE * fp)1321 match_function(const long *f, int pos, FILE *fp)
1322 {
1323 unsigned char buf[FUNCTION_CONTEXT_SIZE];
1324 size_t nc;
1325 int last = lastline;
1326 const char *state = NULL;
1327
1328 lastline = pos;
1329 while (pos > last) {
1330 fseek(fp, f[pos - 1], SEEK_SET);
1331 nc = f[pos] - f[pos - 1];
1332 if (nc >= sizeof(buf))
1333 nc = sizeof(buf) - 1;
1334 nc = fread(buf, 1, nc, fp);
1335 if (nc > 0) {
1336 buf[nc] = '\0';
1337 buf[strcspn(buf, "\n")] = '\0';
1338 if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
1339 if (begins_with(buf, "private:")) {
1340 if (!state)
1341 state = " (private)";
1342 } else if (begins_with(buf, "protected:")) {
1343 if (!state)
1344 state = " (protected)";
1345 } else if (begins_with(buf, "public:")) {
1346 if (!state)
1347 state = " (public)";
1348 } else {
1349 strlcpy(lastbuf, buf, sizeof lastbuf);
1350 if (state)
1351 strlcat(lastbuf, state,
1352 sizeof lastbuf);
1353 lastmatchline = pos;
1354 return lastbuf;
1355 }
1356 }
1357 }
1358 pos--;
1359 }
1360 return lastmatchline > 0 ? lastbuf : NULL;
1361 }
1362
1363 /* dump accumulated "context" diff changes */
1364 static void
dump_context_vec(FILE * f1,FILE * f2,int flags)1365 dump_context_vec(FILE *f1, FILE *f2, int flags)
1366 {
1367 struct context_vec *cvp = context_vec_start;
1368 int lowa, upb, lowc, upd, do_output;
1369 int a, b, c, d;
1370 char ch, *f;
1371
1372 if (context_vec_start > context_vec_ptr)
1373 return;
1374
1375 b = d = 0; /* gcc */
1376 lowa = MAX(1, cvp->a - diff_context);
1377 upb = MIN(len[0], context_vec_ptr->b + diff_context);
1378 lowc = MAX(1, cvp->c - diff_context);
1379 upd = MIN(len[1], context_vec_ptr->d + diff_context);
1380
1381 diff_output("***************");
1382 if ((flags & D_PROTOTYPE)) {
1383 f = match_function(ixold, lowa-1, f1);
1384 if (f != NULL)
1385 diff_output(" %s", f);
1386 }
1387 diff_output("\n*** ");
1388 range(lowa, upb, ",");
1389 diff_output(" ****\n");
1390
1391 /*
1392 * Output changes to the "old" file. The first loop suppresses
1393 * output if there were no changes to the "old" file (we'll see
1394 * the "old" lines as context in the "new" list).
1395 */
1396 do_output = 0;
1397 for (; cvp <= context_vec_ptr; cvp++)
1398 if (cvp->a <= cvp->b) {
1399 cvp = context_vec_start;
1400 do_output++;
1401 break;
1402 }
1403 if (do_output) {
1404 while (cvp <= context_vec_ptr) {
1405 a = cvp->a;
1406 b = cvp->b;
1407 c = cvp->c;
1408 d = cvp->d;
1409
1410 if (a <= b && c <= d)
1411 ch = 'c';
1412 else
1413 ch = (a <= b) ? 'd' : 'a';
1414
1415 if (ch == 'a')
1416 fetch(ixold, lowa, b, f1, ' ', 0, flags);
1417 else {
1418 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1419 fetch(ixold, a, b, f1,
1420 ch == 'c' ? '!' : '-', 0, flags);
1421 }
1422 lowa = b + 1;
1423 cvp++;
1424 }
1425 fetch(ixold, b + 1, upb, f1, ' ', 0, flags);
1426 }
1427 /* output changes to the "new" file */
1428 diff_output("--- ");
1429 range(lowc, upd, ",");
1430 diff_output(" ----\n");
1431
1432 do_output = 0;
1433 for (cvp = context_vec_start; cvp <= context_vec_ptr; cvp++)
1434 if (cvp->c <= cvp->d) {
1435 cvp = context_vec_start;
1436 do_output++;
1437 break;
1438 }
1439 if (do_output) {
1440 while (cvp <= context_vec_ptr) {
1441 a = cvp->a;
1442 b = cvp->b;
1443 c = cvp->c;
1444 d = cvp->d;
1445
1446 if (a <= b && c <= d)
1447 ch = 'c';
1448 else
1449 ch = (a <= b) ? 'd' : 'a';
1450
1451 if (ch == 'd')
1452 fetch(ixnew, lowc, d, f2, ' ', 0, flags);
1453 else {
1454 fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
1455 fetch(ixnew, c, d, f2,
1456 ch == 'c' ? '!' : '+', 0, flags);
1457 }
1458 lowc = d + 1;
1459 cvp++;
1460 }
1461 fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
1462 }
1463 context_vec_ptr = context_vec_start - 1;
1464 }
1465
1466 /* dump accumulated "unified" diff changes */
1467 static void
dump_unified_vec(FILE * f1,FILE * f2,int flags)1468 dump_unified_vec(FILE *f1, FILE *f2, int flags)
1469 {
1470 struct context_vec *cvp = context_vec_start;
1471 int lowa, upb, lowc, upd;
1472 int a, b, c, d;
1473 char ch, *f;
1474
1475 if (context_vec_start > context_vec_ptr)
1476 return;
1477
1478 b = d = 0; /* gcc */
1479 lowa = MAX(1, cvp->a - diff_context);
1480 upb = MIN(len[0], context_vec_ptr->b + diff_context);
1481 lowc = MAX(1, cvp->c - diff_context);
1482 upd = MIN(len[1], context_vec_ptr->d + diff_context);
1483
1484 diff_output("@@ -");
1485 uni_range(lowa, upb);
1486 diff_output(" +");
1487 uni_range(lowc, upd);
1488 diff_output(" @@");
1489 if ((flags & D_PROTOTYPE)) {
1490 f = match_function(ixold, lowa-1, f1);
1491 if (f != NULL)
1492 diff_output(" %s", f);
1493 }
1494 diff_output("\n");
1495
1496 /*
1497 * Output changes in "unified" diff format--the old and new lines
1498 * are printed together.
1499 */
1500 for (; cvp <= context_vec_ptr; cvp++) {
1501 a = cvp->a;
1502 b = cvp->b;
1503 c = cvp->c;
1504 d = cvp->d;
1505
1506 /*
1507 * c: both new and old changes
1508 * d: only changes in the old file
1509 * a: only changes in the new file
1510 */
1511 if (a <= b && c <= d)
1512 ch = 'c';
1513 else
1514 ch = (a <= b) ? 'd' : 'a';
1515
1516 switch (ch) {
1517 case 'c':
1518 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1519 fetch(ixold, a, b, f1, '-', 0, flags);
1520 fetch(ixnew, c, d, f2, '+', 0, flags);
1521 break;
1522 case 'd':
1523 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1524 fetch(ixold, a, b, f1, '-', 0, flags);
1525 break;
1526 case 'a':
1527 fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
1528 fetch(ixnew, c, d, f2, '+', 0, flags);
1529 break;
1530 }
1531 lowa = b + 1;
1532 lowc = d + 1;
1533 }
1534 fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
1535
1536 context_vec_ptr = context_vec_start - 1;
1537 }
1538
1539 static void
print_header(const char * file1,const char * file2)1540 print_header(const char *file1, const char *file2)
1541 {
1542 const char *time_format;
1543 char buf1[256];
1544 char buf2[256];
1545 char end1[10];
1546 char end2[10];
1547 struct tm tm1, tm2, *tm_ptr1, *tm_ptr2;
1548 int nsec1 = stb1.st_mtim.tv_nsec;
1549 int nsec2 = stb2.st_mtim.tv_nsec;
1550
1551 time_format = "%Y-%m-%d %H:%M:%S";
1552
1553 if (cflag)
1554 time_format = "%c";
1555 tm_ptr1 = localtime_r(&stb1.st_mtime, &tm1);
1556 tm_ptr2 = localtime_r(&stb2.st_mtime, &tm2);
1557 strftime(buf1, 256, time_format, tm_ptr1);
1558 strftime(buf2, 256, time_format, tm_ptr2);
1559 if (!cflag) {
1560 strftime(end1, 10, "%z", tm_ptr1);
1561 strftime(end2, 10, "%z", tm_ptr2);
1562 sprintf(buf1, "%s.%.9d %s", buf1, nsec1, end1);
1563 sprintf(buf2, "%s.%.9d %s", buf2, nsec2, end2);
1564 }
1565 if (label[0] != NULL)
1566 diff_output("%s %s\n", diff_format == D_CONTEXT ? "***" : "---",
1567 label[0]);
1568 else
1569 diff_output("%s %s\t%s\n", diff_format == D_CONTEXT ? "***" : "---",
1570 file1, buf1);
1571 if (label[1] != NULL)
1572 diff_output("%s %s\n", diff_format == D_CONTEXT ? "---" : "+++",
1573 label[1]);
1574 else
1575 diff_output("%s %s\t%s\n", diff_format == D_CONTEXT ? "---" : "+++",
1576 file2, buf2);
1577 }
1578