1 /* $OpenBSD: diffreg.c,v 1.93 2019/06/28 13:35:00 deraadt Exp $ */
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66 * @(#)diffreg.c 8.1 (Berkeley) 6/6/93
69 #include <sys/cdefs.h>
70 __FBSDID("$FreeBSD$");
72 #include <sys/capsicum.h>
75 #include <capsicum_helpers.h>
95 * diff - compare two files.
99 * Uses an algorithm due to Harold Stone, which finds a pair of longest
100 * identical subsequences in the two files.
102 * The major goal is to generate the match vector J. J[i] is the index of
103 * the line in file1 corresponding to line i file0. J[i] = 0 if there is no
104 * such line in file1.
106 * Lines are hashed so as to work in core. All potential matches are
107 * located by sorting the lines of each file on the hash (called
108 * ``value''). In particular, this collects the equivalence classes in
109 * file1 together. Subroutine equiv replaces the value of each line in
110 * file0 by the index of the first element of its matching equivalence in
111 * (the reordered) file1. To save space equiv squeezes file1 into a single
112 * array member in which the equivalence classes are simply concatenated,
113 * except that their first members are flagged by changing sign.
115 * Next the indices that point into member are unsorted into array class
116 * according to the original order of file0.
118 * The cleverness lies in routine stone. This marches through the lines of
119 * file0, developing a vector klist of "k-candidates". At step i
120 * a k-candidate is a matched pair of lines x,y (x in file0 y in file1)
121 * such that there is a common subsequence of length k between the first
122 * i lines of file0 and the first y lines of file1, but there is no such
123 * subsequence for any smaller y. x is the earliest possible mate to y that
124 * occurs in such a subsequence.
126 * Whenever any of the members of the equivalence class of lines in file1
127 * matable to a line in file0 has serial number less than the y of some
128 * k-candidate, that k-candidate with the smallest such y is replaced. The
129 * new k-candidate is chained (via pred) to the current k-1 candidate so
130 * that the actual subsequence can be recovered. When a member has serial
131 * number greater that the y of all k-candidates, the klist is extended. At
132 * the end, the longest subsequence is pulled out and placed in the array J
135 * With J in hand, the matches there recorded are check'ed against reality
136 * to assure that no spurious matches have crept in due to hashing. If they
137 * have, they are broken, and "jackpot" is recorded -- a harmless matter
138 * except that a true match for a spuriously mated line may now be
139 * unnecessarily reported as a change.
141 * Much of the complexity of the program comes simply from trying to
142 * minimize core utilization and maximize the range of doable problems by
143 * dynamically allocating what is needed and reusing what is not. The core
144 * requirements for problems larger than somewhat are (in words)
145 * 2*length(file0) + length(file1) + 3*(number of k-candidates installed),
146 * typically about 6n words for files of length n.
161 * The following struct is used to record change information when
162 * doing a "context" or "unified" diff. (see routine "change" to
163 * understand the highly mnemonic field names)
166 int a; /* start line in old file */
167 int b; /* end line in old file */
168 int c; /* start line in new file */
169 int d; /* end line in new file */
172 enum readhash { RH_BINARY, RH_OK, RH_EOF };
175 static FILE *opentemp(const char *);
176 static void output(char *, FILE *, char *, FILE *, int);
177 static void check(FILE *, FILE *, int);
178 static void range(int, int, const char *);
179 static void uni_range(int, int);
180 static void dump_context_vec(FILE *, FILE *, int);
181 static void dump_unified_vec(FILE *, FILE *, int);
182 static bool prepare(int, FILE *, size_t, int);
183 static void prune(void);
184 static void equiv(struct line *, int, struct line *, int, int *);
185 static void unravel(int);
186 static void unsort(struct line *, int, int *);
187 static void change(char *, FILE *, char *, FILE *, int, int, int, int, int *);
188 static void sort(struct line *, int);
189 static void print_header(const char *, const char *);
190 static void print_space(int, int, int);
191 static bool ignoreline_pattern(char *);
192 static bool ignoreline(char *, bool);
193 static int asciifile(FILE *);
194 static int fetch(long *, int, int, FILE *, int, int, int);
195 static int newcand(int, int, int);
196 static int search(int *, int, int);
197 static int skipline(FILE *);
198 static int stone(int *, int, int *, int *, int);
199 static enum readhash readhash(FILE *, int, unsigned *);
200 static int files_differ(FILE *, FILE *, int);
201 static char *match_function(const long *, int, FILE *);
202 static char *preadline(int, size_t, off_t);
204 static int *J; /* will be overlaid on class */
205 static int *class; /* will be overlaid on file[0] */
206 static int *klist; /* will be overlaid on file[0] after class */
207 static int *member; /* will be overlaid on file[1] */
209 static int inifdef; /* whether or not we are in a #ifdef block */
211 static int pref, suff; /* length of prefix and suffix */
213 static int anychange;
214 static int hw, padding; /* half width and padding */
216 static long *ixnew; /* will be overlaid on file[1] */
217 static long *ixold; /* will be overlaid on klist */
218 static struct cand *clist; /* merely a free storage pot for candidates */
219 static int clistlen; /* the length of clist */
220 static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
221 static int (*chrtran)(int); /* translation table for case-folding */
222 static struct context_vec *context_vec_start;
223 static struct context_vec *context_vec_end;
224 static struct context_vec *context_vec_ptr;
226 #define FUNCTION_CONTEXT_SIZE 55
227 static char lastbuf[FUNCTION_CONTEXT_SIZE];
229 static int lastmatchline;
246 diffreg(char *file1, char *file2, int flags, int capsicum)
250 struct pr *pr = NULL;
251 cap_rights_t rights_ro;
260 * hw excludes padding and make sure when -t is not used,
261 * the second column always starts from the closest tab stop
263 if (diff_format == D_SIDEBYSIDE) {
265 padding = tabsize - (hw % tabsize);
266 if ((flags & D_EXPANDTABS) != 0 || (padding % tabsize == 0))
270 ((padding == MIN_PAD) ? (padding << 1) : padding) - 1;
274 if (flags & D_IGNORECASE)
278 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
279 return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
280 if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0)
283 if (flags & D_EMPTY1)
284 f1 = fopen(_PATH_DEVNULL, "r");
286 if (!S_ISREG(stb1.st_mode)) {
287 if ((f1 = opentemp(file1)) == NULL ||
288 fstat(fileno(f1), &stb1) == -1) {
294 } else if (strcmp(file1, "-") == 0)
297 f1 = fopen(file1, "r");
306 if (flags & D_EMPTY2)
307 f2 = fopen(_PATH_DEVNULL, "r");
309 if (!S_ISREG(stb2.st_mode)) {
310 if ((f2 = opentemp(file2)) == NULL ||
311 fstat(fileno(f2), &stb2) == -1) {
317 } else if (strcmp(file2, "-") == 0)
320 f2 = fopen(file2, "r");
330 pr = start_pr(file1, file2);
333 cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT, CAP_SEEK);
334 if (caph_rights_limit(fileno(f1), &rights_ro) < 0)
335 err(2, "unable to limit rights on: %s", file1);
336 if (caph_rights_limit(fileno(f2), &rights_ro) < 0)
337 err(2, "unable to limit rights on: %s", file2);
338 if (fileno(f1) == STDIN_FILENO || fileno(f2) == STDIN_FILENO) {
339 /* stdin has already been limited */
340 if (caph_limit_stderr() == -1)
341 err(2, "unable to limit stderr");
342 if (caph_limit_stdout() == -1)
343 err(2, "unable to limit stdout");
344 } else if (caph_limit_stdio() == -1)
345 err(2, "unable to limit stdio");
347 caph_cache_catpages();
349 if (caph_enter() < 0)
350 err(2, "unable to enter capability mode");
353 switch (files_differ(f1, f2, flags)) {
365 if (diff_format == D_BRIEF && ignore_pats == NULL &&
366 (flags & (D_FOLDBLANKS|D_IGNOREBLANKS|D_IGNORECASE|D_STRIPCR)) == 0)
372 if ((flags & D_FORCEASCII) != 0) {
373 (void)prepare(0, f1, stb1.st_size, flags);
374 (void)prepare(1, f2, stb2.st_size, flags);
375 } else if (!asciifile(f1) || !asciifile(f2) ||
376 !prepare(0, f1, stb1.st_size, flags) ||
377 !prepare(1, f2, stb2.st_size, flags)) {
384 sort(sfile[0], slen[0]);
385 sort(sfile[1], slen[1]);
387 member = (int *)file[1];
388 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
389 member = xreallocarray(member, slen[1] + 2, sizeof(*member));
391 class = (int *)file[0];
392 unsort(sfile[0], slen[0], class);
393 class = xreallocarray(class, slen[0] + 2, sizeof(*class));
395 klist = xcalloc(slen[0] + 2, sizeof(*klist));
398 clist = xcalloc(clistlen, sizeof(*clist));
399 i = stone(class, slen[0], member, klist, flags);
403 J = xreallocarray(J, len[0] + 2, sizeof(*J));
408 ixold = xreallocarray(ixold, len[0] + 2, sizeof(*ixold));
409 ixnew = xreallocarray(ixnew, len[1] + 2, sizeof(*ixnew));
410 check(f1, f2, flags);
411 output(file1, f1, file2, f2, flags);
430 * Check to see if the given files differ.
431 * Returns 0 if they are the same, 1 if different, and -1 on error.
432 * XXX - could use code from cmp(1) [faster]
435 files_differ(FILE *f1, FILE *f2, int flags)
437 char buf1[BUFSIZ], buf2[BUFSIZ];
440 if ((flags & (D_EMPTY1|D_EMPTY2)) || stb1.st_size != stb2.st_size ||
441 (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT))
444 if (stb1.st_dev == stb2.st_dev && stb1.st_ino == stb2.st_ino)
448 i = fread(buf1, 1, sizeof(buf1), f1);
449 j = fread(buf2, 1, sizeof(buf2), f2);
450 if ((!i && ferror(f1)) || (!j && ferror(f2)))
456 if (memcmp(buf1, buf2, i) != 0)
462 opentemp(const char *f)
464 char buf[BUFSIZ], tempfile[PATH_MAX];
468 if (strcmp(f, "-") == 0)
470 else if ((ifd = open(f, O_RDONLY, 0644)) == -1)
473 (void)strlcpy(tempfile, _PATH_TMP "/diff.XXXXXXXX", sizeof(tempfile));
475 if ((ofd = mkstemp(tempfile)) == -1) {
480 while ((nread = read(ifd, buf, BUFSIZ)) > 0) {
481 if (write(ofd, buf, nread) != nread) {
488 lseek(ofd, (off_t)0, SEEK_SET);
489 return (fdopen(ofd, "r"));
493 prepare(int i, FILE *fd, size_t filesize, int flags)
502 sz = MIN(filesize, SIZE_MAX) / 25;
506 p = xcalloc(sz + 3, sizeof(*p));
507 while ((r = readhash(fd, flags, &h)) != RH_EOF)
509 case RH_EOF: /* otherwise clang complains */
515 p = xreallocarray(p, sz + 3, sizeof(*p));
531 for (pref = 0; pref < len[0] && pref < len[1] &&
532 file[0][pref + 1].value == file[1][pref + 1].value;
535 for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
536 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
539 for (j = 0; j < 2; j++) {
540 sfile[j] = file[j] + pref;
541 slen[j] = len[j] - pref - suff;
542 for (i = 0; i <= slen[j]; i++)
543 sfile[j][i].serial = i;
548 equiv(struct line *a, int n, struct line *b, int m, int *c)
553 while (i <= n && j <= m) {
554 if (a[i].value < b[j].value)
556 else if (a[i].value == b[j].value)
567 while (b[j + 1].value == b[j].value) {
576 stone(int *a, int n, int *b, int *c, int flags)
579 int oldc, tc, oldl, sq;
580 unsigned numtries, bound;
582 if (flags & D_MINIMAL)
586 bound = MAX(256, sq);
590 c[0] = newcand(0, 0, 0);
591 for (i = 1; i <= n; i++) {
600 if (y <= clist[oldc].y)
606 if (clist[c[l]].y <= y)
609 c[l] = newcand(i, y, oldc);
614 c[l] = newcand(i, y, oldc);
618 } while ((y = b[++j]) > 0 && numtries < bound);
624 newcand(int x, int y, int pred)
628 if (clen == clistlen) {
629 clistlen = clistlen * 11 / 10;
630 clist = xreallocarray(clist, clistlen, sizeof(*clist));
640 search(int *c, int k, int y)
644 if (clist[c[k]].y < y) /* quick look for typical case */
669 for (i = 0; i <= len[0]; i++)
670 J[i] = i <= pref ? i :
671 i > len[0] - suff ? i + len[1] - len[0] : 0;
672 for (q = clist + p; q->y != 0; q = clist + q->pred)
673 J[q->x + pref] = q->y + pref;
677 * Check does double duty:
678 * 1. ferret out any fortuitous correspondences due to confounding by
679 * hashing (which result in "jackpot")
680 * 2. collect random access indexes to the two files
683 check(FILE *f1, FILE *f2, int flags)
685 int i, j, /* jackpot, */ c, d;
691 ixold[0] = ixnew[0] = 0;
694 for (i = 1; i <= len[0]; i++) {
696 ixold[i] = ctold += skipline(f1);
700 ixnew[j] = ctnew += skipline(f2);
703 if (flags & (D_FOLDBLANKS | D_IGNOREBLANKS | D_IGNORECASE | D_STRIPCR)) {
708 * GNU diff ignores a missing newline
709 * in one file for -b or -w.
711 if (flags & (D_FOLDBLANKS | D_IGNOREBLANKS)) {
712 if (c == EOF && d == '\n') {
715 } else if (c == '\n' && d == EOF) {
722 if (flags & D_STRIPCR && (c == '\r' || d == '\r')) {
724 if ((c = getc(f1)) == '\n') {
731 if ((d = getc(f2)) == '\n') {
739 if ((flags & D_FOLDBLANKS) && isspace(c) &&
745 } while (isspace(c = getc(f1)));
750 } while (isspace(d = getc(f2)));
751 } else if (flags & D_IGNOREBLANKS) {
752 while (isspace(c) && c != '\n') {
756 while (isspace(d) && d != '\n') {
761 if (chrtran(c) != chrtran(d)) {
764 if (c != '\n' && c != EOF)
765 ctold += skipline(f1);
766 if (d != '\n' && c != EOF)
767 ctnew += skipline(f2);
770 if (c == '\n' || c == EOF)
777 if ((c = getc(f1)) != (d = getc(f2))) {
780 if (c != '\n' && c != EOF)
781 ctold += skipline(f1);
782 if (d != '\n' && c != EOF)
783 ctnew += skipline(f2);
786 if (c == '\n' || c == EOF)
794 for (; j <= len[1]; j++) {
795 ixnew[j] = ctnew += skipline(f2);
799 * fprintf(stderr, "jackpot\n");
803 /* shellsort CACM #201 */
805 sort(struct line *a, int n)
807 struct line *ai, *aim, w;
812 for (j = 1; j <= n; j *= 2)
814 for (m /= 2; m != 0; m /= 2) {
816 for (j = 1; j <= k; j++) {
817 for (ai = &a[j]; ai > a; ai -= m) {
820 break; /* wraparound */
821 if (aim->value > ai[0].value ||
822 (aim->value == ai[0].value &&
823 aim->serial > ai[0].serial))
825 w.value = ai[0].value;
826 ai[0].value = aim->value;
827 aim->value = w.value;
828 w.serial = ai[0].serial;
829 ai[0].serial = aim->serial;
830 aim->serial = w.serial;
837 unsort(struct line *f, int l, int *b)
841 a = xcalloc(l + 1, sizeof(*a));
842 for (i = 1; i <= l; i++)
843 a[f[i].serial] = f[i].value;
844 for (i = 1; i <= l; i++)
854 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
860 output(char *file1, FILE *f1, char *file2, FILE *f2, int flags)
862 int i, j, m, i0, i1, j0, j1, nc;
868 J[m + 1] = len[1] + 1;
869 if (diff_format != D_EDIT) {
870 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
871 while (i0 <= m && J[i0] == J[i0 - 1] + 1) {
872 if (diff_format == D_SIDEBYSIDE && suppress_common != 1) {
873 nc = fetch(ixold, i0, i0, f1, '\0', 1, flags);
874 print_space(nc, (hw - nc) + (padding << 1) + 1, flags);
875 fetch(ixnew, J[i0], J[i0], f2, '\0', 0, flags);
882 while (i1 < m && J[i1 + 1] == 0)
888 * When using side-by-side, lines from both of the files are
889 * printed. The algorithm used by diff(1) identifies the ranges
890 * in which two files differ.
891 * See the change() function below.
892 * The for loop below consumes the shorter range, whereas one of
893 * the while loops deals with the longer one.
895 if (diff_format == D_SIDEBYSIDE) {
896 for (i = i0, j = j0; i <= i1 && j <= j1; i++, j++)
897 change(file1, f1, file2, f2, i, i, j, j, &flags);
900 change(file1, f1, file2, f2, i, i, j + 1, j, &flags);
905 change(file1, f1, file2, f2, i + 1, i, j, j, &flags);
909 change(file1, f1, file2, f2, i0, i1, j0, j1, &flags);
912 for (i0 = m; i0 >= 1; i0 = i1 - 1) {
913 while (i0 >= 1 && J[i0] == J[i0 + 1] - 1 && J[i0] != 0)
917 while (i1 > 1 && J[i1 - 1] == 0)
921 change(file1, f1, file2, f2, i1, i0, j1, j0, &flags);
925 change(file1, f1, file2, f2, 1, 0, 1, len[1], &flags);
926 if (diff_format == D_IFDEF || diff_format == D_GFORMAT) {
929 if ((c = getc(f1)) == EOF)
935 if (anychange != 0) {
936 if (diff_format == D_CONTEXT)
937 dump_context_vec(f1, f2, flags);
938 else if (diff_format == D_UNIFIED)
939 dump_unified_vec(f1, f2, flags);
944 range(int a, int b, const char *separator)
946 printf("%d", a > b ? b : a);
948 printf("%s%d", separator, b);
952 uni_range(int a, int b)
955 printf("%d,%d", a, b - a + 1);
963 preadline(int fd, size_t rlen, off_t off)
968 line = xmalloc(rlen + 1);
969 if ((nr = pread(fd, line, rlen, off)) == -1)
971 if (nr > 0 && line[nr-1] == '\n')
978 ignoreline_pattern(char *line)
982 ret = regexec(&ignore_re, line, 0, NULL, 0);
983 return (ret == 0); /* if it matched, it should be ignored. */
987 ignoreline(char *line, bool skip_blanks)
990 if (skip_blanks && *line == '\0')
992 if (ignore_pats != NULL && ignoreline_pattern(line))
998 * Indicate that there is a difference between lines a and b of the from file
999 * to get to lines c to d of the to file. If a is greater then b then there
1000 * are no lines in the from file involved and this means that there were
1001 * lines appended (beginning at b). If c is greater than d then there are
1002 * lines missing from the to file.
1005 change(char *file1, FILE *f1, char *file2, FILE *f2, int a, int b, int c, int d,
1008 static size_t max_context = 64;
1012 bool skip_blanks, ignore;
1014 skip_blanks = (*pflags & D_SKIPBLANKLINES);
1016 if ((diff_format != D_IFDEF || diff_format == D_GFORMAT) &&
1019 if (ignore_pats != NULL || skip_blanks) {
1022 * All lines in the change, insert, or delete must match an ignore
1023 * pattern for the change to be ignored.
1025 if (a <= b) { /* Changes and deletes. */
1026 for (i = a; i <= b; i++) {
1027 line = preadline(fileno(f1),
1028 ixold[i] - ixold[i - 1], ixold[i - 1]);
1029 ignore = ignoreline(line, skip_blanks);
1035 if (a > b || c <= d) { /* Changes and inserts. */
1036 for (i = c; i <= d; i++) {
1037 line = preadline(fileno(f2),
1038 ixnew[i] - ixnew[i - 1], ixnew[i - 1]);
1039 ignore = ignoreline(line, skip_blanks);
1048 if (*pflags & D_HEADER && diff_format != D_BRIEF) {
1049 printf("%s %s %s\n", diffargs, file1, file2);
1050 *pflags &= ~D_HEADER;
1052 if (diff_format == D_CONTEXT || diff_format == D_UNIFIED) {
1054 * Allocate change records as needed.
1056 if (context_vec_start == NULL ||
1057 context_vec_ptr == context_vec_end - 1) {
1058 ptrdiff_t offset = -1;
1060 if (context_vec_start != NULL)
1061 offset = context_vec_ptr - context_vec_start;
1063 context_vec_start = xreallocarray(context_vec_start,
1064 max_context, sizeof(*context_vec_start));
1065 context_vec_end = context_vec_start + max_context;
1066 context_vec_ptr = context_vec_start + offset;
1068 if (anychange == 0) {
1070 * Print the context/unidiff header first time through.
1072 print_header(file1, file2);
1074 } else if (a > context_vec_ptr->b + (2 * diff_context) + 1 &&
1075 c > context_vec_ptr->d + (2 * diff_context) + 1) {
1077 * If this change is more than 'diff_context' lines from the
1078 * previous change, dump the record and reset it.
1080 if (diff_format == D_CONTEXT)
1081 dump_context_vec(f1, f2, *pflags);
1083 dump_unified_vec(f1, f2, *pflags);
1086 context_vec_ptr->a = a;
1087 context_vec_ptr->b = b;
1088 context_vec_ptr->c = c;
1089 context_vec_ptr->d = d;
1094 switch (diff_format) {
1100 printf("%c", a > b ? 'a' : c > d ? 'd' : 'c');
1101 if (diff_format == D_NORMAL)
1106 printf("%c", a > b ? 'a' : c > d ? 'd' : 'c');
1112 printf("a%d %d\n", b, d - c + 1);
1114 printf("d%d %d\n", a, b - a + 1);
1116 /* add changed lines */
1117 printf("a%d %d\n", b, d - c + 1);
1121 if (diff_format == D_GFORMAT) {
1123 /* print through if append (a>b), else to (nb: 0 vs 1 orig) */
1124 nc = ixold[a > b ? b : a - 1] - curpos;
1125 for (i = 0; i < nc; i++)
1126 printf("%c", getc(f1));
1127 for (walk = group_format; *walk != '\0'; walk++) {
1132 fetch(ixold, a, b, f1, '<', 1, *pflags);
1135 fetch(ixnew, c, d, f2, '>', 0, *pflags);
1138 printf("%%%c", *walk);
1143 printf("%c", *walk);
1146 if (diff_format == D_SIDEBYSIDE) {
1148 printf("\033[%sm", add_code);
1149 else if (color && c > d)
1150 printf("\033[%sm", del_code);
1152 print_space(0, hw + padding , *pflags);
1154 nc = fetch(ixold, a, b, f1, '\0', 1, *pflags);
1155 print_space(nc, hw - nc + padding, *pflags);
1158 printf("\033[%sm", add_code);
1159 else if (color && c > d)
1160 printf("\033[%sm", del_code);
1161 printf("%c", (a > b) ? '>' : ((c > d) ? '<' : '|'));
1164 print_space(hw + padding + 1 , padding, *pflags);
1165 fetch(ixnew, c, d, f2, '\0', 0, *pflags);
1168 if (diff_format == D_NORMAL || diff_format == D_IFDEF) {
1169 fetch(ixold, a, b, f1, '<', 1, *pflags);
1170 if (a <= b && c <= d && diff_format == D_NORMAL)
1173 if (diff_format != D_GFORMAT && diff_format != D_SIDEBYSIDE)
1174 fetch(ixnew, c, d, f2, diff_format == D_NORMAL ? '>' : '\0', 0, *pflags);
1175 if (edoffset != 0 && diff_format == D_EDIT) {
1177 * A non-zero edoffset value for D_EDIT indicates that the last line
1178 * printed was a bare dot (".") that has been escaped as ".." to
1179 * prevent ed(1) from misinterpreting it. We have to add a
1180 * substitute command to change this back and restart where we left
1184 printf("%ds/.//\n", a + edoffset - 1);
1185 b = a + edoffset - 1;
1190 if ((diff_format == D_EDIT || diff_format == D_REVERSE) && c <= d)
1193 printf("#endif /* %s */\n", ifdefname);
1199 fetch(long *f, int a, int b, FILE *lb, int ch, int oldfile, int flags)
1201 int i, j, c, lastc, col, nc, newcol;
1206 * When doing #ifdef's, copy down to current line
1207 * if this is the first file, so that stuff makes it to output.
1209 if ((diff_format == D_IFDEF) && oldfile) {
1210 long curpos = ftell(lb);
1211 /* print through if append (a>b), else to (nb: 0 vs 1 orig) */
1212 nc = f[a > b ? b : a - 1] - curpos;
1213 for (i = 0; i < nc; i++)
1214 printf("%c", getc(lb));
1218 if (diff_format == D_IFDEF) {
1220 printf("#else /* %s%s */\n",
1221 oldfile == 1 ? "!" : "", ifdefname);
1224 printf("#ifndef %s\n", ifdefname);
1226 printf("#ifdef %s\n", ifdefname);
1228 inifdef = 1 + oldfile;
1230 for (i = a; i <= b; i++) {
1231 fseek(lb, f[i - 1], SEEK_SET);
1232 nc = f[i] - f[i - 1];
1233 if (diff_format == D_SIDEBYSIDE && hw < nc)
1235 if (diff_format != D_IFDEF && diff_format != D_GFORMAT &&
1237 if (color && (ch == '>' || ch == '+'))
1238 printf("\033[%sm", add_code);
1239 else if (color && (ch == '<' || ch == '-'))
1240 printf("\033[%sm", del_code);
1242 if (Tflag && (diff_format == D_NORMAL ||
1243 diff_format == D_CONTEXT ||
1244 diff_format == D_UNIFIED))
1246 else if (diff_format != D_UNIFIED)
1251 while (j < nc && (hw == 0 || col < hw)) {
1253 if (flags & D_STRIPCR && c == '\r') {
1254 if ((c = getc(lb)) == '\n')
1262 if (diff_format == D_EDIT ||
1263 diff_format == D_REVERSE ||
1264 diff_format == D_NREVERSE)
1265 warnx("No newline at end of file");
1267 printf("\n\\ No newline at end of file\n");
1271 * when using --side-by-side, col needs to be increased
1272 * in any case to keep the columns aligned
1275 if (flags & D_EXPANDTABS) {
1276 newcol = ((col / tabsize) + 1) * tabsize;
1279 } while (++col < newcol && col < hw);
1281 if (diff_format == D_SIDEBYSIDE) {
1282 if ((col + tabsize) > hw) {
1283 printf("%*s", hw - col, "");
1295 if (diff_format == D_EDIT && j == 1 && c == '\n' &&
1298 * Don't print a bare "." line since that will confuse
1299 * ed(1). Print ".." instead and set the, global variable
1300 * edoffset to an offset from which to restart. The
1301 * caller must check the value of edoffset
1304 edoffset = i - a + 1;
1307 /* when side-by-side, do not print a newline */
1308 if (diff_format != D_SIDEBYSIDE || c != '\n') {
1309 if (color && c == '\n')
1310 printf("\033[m%c", c);
1321 if (color && diff_format == D_SIDEBYSIDE)
1327 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
1329 static enum readhash
1330 readhash(FILE *f, int flags, unsigned *hash)
1338 switch (t = getc(f)) {
1340 if ((flags & D_FORCEASCII) == 0)
1344 if (flags & D_STRIPCR) {
1355 if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) != 0) {
1362 if (space && (flags & D_IGNOREBLANKS) == 0) {
1366 sum = sum * 127 + chrtran(t);
1385 unsigned char buf[BUFSIZ];
1392 cnt = fread(buf, 1, sizeof(buf), f);
1393 return (memchr(buf, '\0', cnt) == NULL);
1396 #define begins_with(s, pre) (strncmp(s, pre, sizeof(pre) - 1) == 0)
1399 match_function(const long *f, int pos, FILE *fp)
1401 unsigned char buf[FUNCTION_CONTEXT_SIZE];
1403 int last = lastline;
1404 const char *state = NULL;
1407 for (; pos > last; pos--) {
1408 fseek(fp, f[pos - 1], SEEK_SET);
1409 nc = f[pos] - f[pos - 1];
1410 if (nc >= sizeof(buf))
1411 nc = sizeof(buf) - 1;
1412 nc = fread(buf, 1, nc, fp);
1416 buf[strcspn(buf, "\n")] = '\0';
1417 if (most_recent_pat != NULL) {
1418 int ret = regexec(&most_recent_re, buf, 0, NULL, 0);
1422 strlcpy(lastbuf, buf, sizeof(lastbuf));
1423 lastmatchline = pos;
1425 } else if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$'
1426 || buf[0] == '-' || buf[0] == '+') {
1427 if (begins_with(buf, "private:")) {
1429 state = " (private)";
1430 } else if (begins_with(buf, "protected:")) {
1432 state = " (protected)";
1433 } else if (begins_with(buf, "public:")) {
1435 state = " (public)";
1437 strlcpy(lastbuf, buf, sizeof(lastbuf));
1439 strlcat(lastbuf, state, sizeof(lastbuf));
1440 lastmatchline = pos;
1445 return (lastmatchline > 0 ? lastbuf : NULL);
1448 /* dump accumulated "context" diff changes */
1450 dump_context_vec(FILE *f1, FILE *f2, int flags)
1452 struct context_vec *cvp = context_vec_start;
1453 int lowa, upb, lowc, upd, do_output;
1457 if (context_vec_start > context_vec_ptr)
1460 b = d = 0; /* gcc */
1461 lowa = MAX(1, cvp->a - diff_context);
1462 upb = MIN(len[0], context_vec_ptr->b + diff_context);
1463 lowc = MAX(1, cvp->c - diff_context);
1464 upd = MIN(len[1], context_vec_ptr->d + diff_context);
1466 printf("***************");
1467 if (flags & (D_PROTOTYPE | D_MATCHLAST)) {
1468 f = match_function(ixold, cvp->a - 1, f1);
1473 range(lowa, upb, ",");
1477 * Output changes to the "old" file. The first loop suppresses
1478 * output if there were no changes to the "old" file (we'll see
1479 * the "old" lines as context in the "new" list).
1482 for (; cvp <= context_vec_ptr; cvp++)
1483 if (cvp->a <= cvp->b) {
1484 cvp = context_vec_start;
1489 while (cvp <= context_vec_ptr) {
1495 if (a <= b && c <= d)
1498 ch = (a <= b) ? 'd' : 'a';
1501 fetch(ixold, lowa, b, f1, ' ', 0, flags);
1503 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1504 fetch(ixold, a, b, f1,
1505 ch == 'c' ? '!' : '-', 0, flags);
1510 fetch(ixold, b + 1, upb, f1, ' ', 0, flags);
1512 /* output changes to the "new" file */
1514 range(lowc, upd, ",");
1518 for (cvp = context_vec_start; cvp <= context_vec_ptr; cvp++)
1519 if (cvp->c <= cvp->d) {
1520 cvp = context_vec_start;
1525 while (cvp <= context_vec_ptr) {
1531 if (a <= b && c <= d)
1534 ch = (a <= b) ? 'd' : 'a';
1537 fetch(ixnew, lowc, d, f2, ' ', 0, flags);
1539 fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
1540 fetch(ixnew, c, d, f2,
1541 ch == 'c' ? '!' : '+', 0, flags);
1546 fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
1548 context_vec_ptr = context_vec_start - 1;
1551 /* dump accumulated "unified" diff changes */
1553 dump_unified_vec(FILE *f1, FILE *f2, int flags)
1555 struct context_vec *cvp = context_vec_start;
1556 int lowa, upb, lowc, upd;
1560 if (context_vec_start > context_vec_ptr)
1563 b = d = 0; /* gcc */
1564 lowa = MAX(1, cvp->a - diff_context);
1565 upb = MIN(len[0], context_vec_ptr->b + diff_context);
1566 lowc = MAX(1, cvp->c - diff_context);
1567 upd = MIN(len[1], context_vec_ptr->d + diff_context);
1570 uni_range(lowa, upb);
1572 uni_range(lowc, upd);
1574 if (flags & (D_PROTOTYPE | D_MATCHLAST)) {
1575 f = match_function(ixold, cvp->a - 1, f1);
1582 * Output changes in "unified" diff format--the old and new lines
1583 * are printed together.
1585 for (; cvp <= context_vec_ptr; cvp++) {
1592 * c: both new and old changes
1593 * d: only changes in the old file
1594 * a: only changes in the new file
1596 if (a <= b && c <= d)
1599 ch = (a <= b) ? 'd' : 'a';
1603 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1604 fetch(ixold, a, b, f1, '-', 0, flags);
1605 fetch(ixnew, c, d, f2, '+', 0, flags);
1608 fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
1609 fetch(ixold, a, b, f1, '-', 0, flags);
1612 fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
1613 fetch(ixnew, c, d, f2, '+', 0, flags);
1619 fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
1621 context_vec_ptr = context_vec_start - 1;
1625 print_header(const char *file1, const char *file2)
1627 const char *time_format;
1629 struct tm tm1, tm2, *tm_ptr1, *tm_ptr2;
1630 int nsec1 = stb1.st_mtim.tv_nsec;
1631 int nsec2 = stb2.st_mtim.tv_nsec;
1633 time_format = "%Y-%m-%d %H:%M:%S";
1637 tm_ptr1 = localtime_r(&stb1.st_mtime, &tm1);
1638 tm_ptr2 = localtime_r(&stb2.st_mtime, &tm2);
1639 if (label[0] != NULL)
1640 printf("%s %s\n", diff_format == D_CONTEXT ? "***" : "---",
1643 strftime(buf, sizeof(buf), time_format, tm_ptr1);
1644 printf("%s %s\t%s", diff_format == D_CONTEXT ? "***" : "---",
1647 strftime(buf, sizeof(buf), "%z", tm_ptr1);
1648 printf(".%.9d %s", nsec1, buf);
1652 if (label[1] != NULL)
1653 printf("%s %s\n", diff_format == D_CONTEXT ? "---" : "+++",
1656 strftime(buf, sizeof(buf), time_format, tm_ptr2);
1657 printf("%s %s\t%s", diff_format == D_CONTEXT ? "---" : "+++",
1660 strftime(buf, sizeof(buf), "%z", tm_ptr2);
1661 printf(".%.9d %s", nsec2, buf);
1668 * Prints n number of space characters either by using tab
1669 * or single space characters.
1670 * nc is the preceding number of characters
1673 print_space(int nc, int n, int flags) {
1677 if ((flags & D_EXPANDTABS) == 0) {
1678 /* first tabstop may be closer than tabsize */
1679 i = tabsize - (nc % tabsize);
1680 while (col >= tabsize) {
1686 printf("%*s", col, "");