1 /* $OpenBSD: diffreg.c,v 1.91 2016/03/01 20:57:35 natano Exp $ */
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41 * modification, are permitted provided that the following conditions
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54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * @(#)diffreg.c 8.1 (Berkeley) 6/6/93
69 #include <sys/queue.h>
87 #include "got_error.h"
88 #include "got_object.h"
91 #include "got_lib_diff.h"
93 #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
94 #define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b))
97 * diff - compare two files.
101 * Uses an algorithm due to Harold Stone, which finds
102 * a pair of longest identical subsequences in the two
105 * The major goal is to generate the match vector J.
106 * J[i] is the index of the line in file1 corresponding
107 * to line i file0. J[i] = 0 if there is no
108 * such line in file1.
110 * Lines are hashed so as to work in core. All potential
111 * matches are located by sorting the lines of each file
112 * on the hash (called ``value''). In particular, this
113 * collects the equivalence classes in file1 together.
114 * Subroutine equiv replaces the value of each line in
115 * file0 by the index of the first element of its
116 * matching equivalence in (the reordered) file1.
117 * To save space equiv squeezes file1 into a single
118 * array member in which the equivalence classes
119 * are simply concatenated, except that their first
120 * members are flagged by changing sign.
122 * Next the indices that point into member are unsorted into
123 * array class according to the original order of file0.
125 * The cleverness lies in routine stone. This marches
126 * through the lines of file0, developing a vector klist
127 * of "k-candidates". At step i a k-candidate is a matched
128 * pair of lines x,y (x in file0 y in file1) such that
129 * there is a common subsequence of length k
130 * between the first i lines of file0 and the first y
131 * lines of file1, but there is no such subsequence for
132 * any smaller y. x is the earliest possible mate to y
133 * that occurs in such a subsequence.
135 * Whenever any of the members of the equivalence class of
136 * lines in file1 matable to a line in file0 has serial number
137 * less than the y of some k-candidate, that k-candidate
138 * with the smallest such y is replaced. The new
139 * k-candidate is chained (via pred) to the current
140 * k-1 candidate so that the actual subsequence can
141 * be recovered. When a member has serial number greater
142 * that the y of all k-candidates, the klist is extended.
143 * At the end, the longest subsequence is pulled out
144 * and placed in the array J by unravel
146 * With J in hand, the matches there recorded are
147 * check'ed against reality to assure that no spurious
148 * matches have crept in due to hashing. If they have,
149 * they are broken, and "jackpot" is recorded--a harmless
150 * matter except that a true match for a spuriously
151 * mated line may now be unnecessarily reported as a change.
153 * Much of the complexity of the program comes simply
154 * from trying to minimize core utilization and
155 * maximize the range of doable problems by dynamically
156 * allocating what is needed and reusing what is not.
157 * The core requirements for problems larger than somewhat
158 * are (in words) 2*length(file0) + length(file1) +
159 * 3*(number of k-candidates installed), typically about
160 * 6n words for files of length n.
175 * The following struct is used to record change information when
176 * doing a "context" or "unified" diff. (see routine "change" to
177 * understand the highly mnemonic field names)
180 int a; /* start line in old file */
181 int b; /* end line in old file */
182 int c; /* start line in new file */
183 int d; /* end line in new file */
186 static void diff_output(FILE *, const char *, ...);
187 static int output(FILE *, struct got_diff_state *, struct got_diff_args *, const char *, FILE *, const char *, FILE *, int);
188 static void check(struct got_diff_state *, FILE *, FILE *, int);
189 static void range(FILE *, int, int, char *);
190 static void uni_range(FILE *, int, int);
191 static void dump_context_vec(FILE *, struct got_diff_state *, struct got_diff_args *, FILE *, FILE *, int);
192 static void dump_unified_vec(FILE *, struct got_diff_state *, struct got_diff_args *, FILE *, FILE *, int);
193 static int prepare(struct got_diff_state *, int, FILE *, off_t, int);
194 static void prune(struct got_diff_state *);
195 static void equiv(struct line *, int, struct line *, int, int *);
196 static void unravel(struct got_diff_state *, int);
197 static int unsort(struct line *, int, int *);
198 static int change(FILE *, struct got_diff_state *, struct got_diff_args *, const char *, FILE *, const char *, FILE *, int, int, int, int, int *);
199 static void sort(struct line *, int);
200 static void print_header(FILE *, struct got_diff_state *, struct got_diff_args *, const char *, const char *);
201 static int ignoreline(char *);
202 static int asciifile(FILE *);
203 static int fetch(FILE *, struct got_diff_state *, struct got_diff_args *, long *, int, int, FILE *, int, int, int);
204 static int newcand(struct got_diff_state *, int, int, int, int *);
205 static int search(struct got_diff_state *, int *, int, int);
206 static int skipline(FILE *);
207 static int isqrt(int);
208 static int stone(struct got_diff_state *, int *, int, int *, int *, int);
209 static int readhash(struct got_diff_state *, FILE *, int);
210 static int files_differ(struct got_diff_state *, FILE *, FILE *, int);
211 static char *match_function(struct got_diff_state *, const long *, int, FILE *);
212 static char *preadline(int, size_t, off_t);
215 * chrtran points to one of 2 translation tables: cup2low if folding upper to
216 * lower case clow2low if not folding case
218 u_char clow2low[256] = {
219 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
220 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
221 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
222 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
223 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36,
224 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41,
225 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
226 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
227 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62,
228 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d,
229 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
230 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83,
231 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e,
232 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
233 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4,
234 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
235 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
236 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5,
237 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
238 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
239 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6,
240 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1,
241 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc,
245 u_char cup2low[256] = {
246 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
247 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
248 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
249 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
250 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36,
251 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x60, 0x61,
252 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c,
253 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
254 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x60, 0x61, 0x62,
255 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d,
256 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
257 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83,
258 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e,
259 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
260 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4,
261 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
262 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
263 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5,
264 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
265 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
266 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6,
267 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1,
268 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc,
273 diff_output(FILE *outfile, const char *fmt, ...)
278 vfprintf(outfile, fmt, ap);
282 const struct got_error *
283 got_diffreg(int *rval, FILE *f1, FILE *f2, int flags,
284 struct got_diff_args *args, struct got_diff_state *ds, FILE *outfile)
286 const struct got_error *err = NULL;
293 ds->lastmatchline = 0;
294 ds->context_vec_ptr = ds->context_vec_start - 1;
295 ds->max_context = 64;
296 if (flags & D_IGNORECASE)
297 ds->chrtran = cup2low;
299 ds->chrtran = clow2low;
300 if (S_ISDIR(ds->stb1.st_mode) != S_ISDIR(ds->stb2.st_mode)) {
301 *rval = (S_ISDIR(ds->stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
304 if (flags & D_EMPTY1) {
305 f1 = fopen(_PATH_DEVNULL, "r");
307 err = got_error_from_errno();
311 else if (f1 == NULL) {
316 if (flags & D_EMPTY2) {
317 f2 = fopen(_PATH_DEVNULL, "r");
319 err = got_error_from_errno();
322 } else if (f2 == NULL) {
327 switch (files_differ(ds, f1, f2, flags)) {
338 if ((flags & D_FORCEASCII) == 0 &&
339 (!asciifile(f1) || !asciifile(f2))) {
344 if (prepare(ds, 0, f1, ds->stb1.st_size, flags)) {
345 err = got_error_from_errno();
348 if (prepare(ds, 1, f2, ds->stb2.st_size, flags)) {
349 err = got_error_from_errno();
354 sort(ds->sfile[0], ds->slen[0]);
355 sort(ds->sfile[1], ds->slen[1]);
357 ds->member = (int *)ds->file[1];
358 equiv(ds->sfile[0], ds->slen[0], ds->sfile[1], ds->slen[1], ds->member);
359 p = reallocarray(ds->member, ds->slen[1] + 2, sizeof(*ds->member));
361 err = got_error_from_errno();
366 ds->class = (int *)ds->file[0];
367 if (unsort(ds->sfile[0], ds->slen[0], ds->class)) {
368 err = got_error_from_errno();
371 p = reallocarray(ds->class, ds->slen[0] + 2, sizeof(*ds->class));
373 err = got_error_from_errno();
378 ds->klist = calloc(ds->slen[0] + 2, sizeof(*ds->klist));
379 if (ds->klist == NULL) {
380 err = got_error_from_errno();
385 ds->clist = calloc(ds->clistlen, sizeof(*ds->clist));
386 if (ds->clist == NULL) {
387 err = got_error_from_errno();
390 i = stone(ds, ds->class, ds->slen[0], ds->member, ds->klist, flags);
392 err = got_error_from_errno();
396 p = reallocarray(ds->J, ds->len[0] + 2, sizeof(*ds->J));
398 err = got_error_from_errno();
402 unravel(ds, ds->klist[i]);
404 lp = reallocarray(ds->ixold, ds->len[0] + 2, sizeof(*ds->ixold));
406 err = got_error_from_errno();
410 lp = reallocarray(ds->ixnew, ds->len[1] + 2, sizeof(*ds->ixnew));
412 err = got_error_from_errno();
416 check(ds, f1, f2, flags);
417 if (output(outfile, ds, args, args->label[0], f1, args->label[1], f2,
419 err = got_error_from_errno();
442 * Check to see if the given files differ.
443 * Returns 0 if they are the same, 1 if different, and -1 on error.
444 * XXX - could use code from cmp(1) [faster]
447 files_differ(struct got_diff_state *ds, FILE *f1, FILE *f2, int flags)
449 char buf1[BUFSIZ], buf2[BUFSIZ];
452 if ((flags & (D_EMPTY1|D_EMPTY2)) || ds->stb1.st_size != ds->stb2.st_size ||
453 (ds->stb1.st_mode & S_IFMT) != (ds->stb2.st_mode & S_IFMT))
456 i = fread(buf1, 1, sizeof(buf1), f1);
457 j = fread(buf2, 1, sizeof(buf2), f2);
458 if ((!i && ferror(f1)) || (!j && ferror(f2)))
464 if (memcmp(buf1, buf2, i) != 0)
470 prepare(struct got_diff_state *ds, int i, FILE *fd, off_t filesize, int flags)
478 sz = (filesize <= SIZE_MAX ? filesize : SIZE_MAX) / 25;
482 p = calloc(sz + 3, sizeof(*p));
485 for (j = 0; (h = readhash(ds, fd, flags));) {
488 q = reallocarray(p, sz + 3, sizeof(*p));
504 prune(struct got_diff_state *ds)
508 for (ds->pref = 0; ds->pref < ds->len[0] && ds->pref < ds->len[1] &&
509 ds->file[0][ds->pref + 1].value == ds->file[1][ds->pref + 1].value;
512 for (ds->suff = 0; ds->suff < ds->len[0] - ds->pref && ds->suff < ds->len[1] - ds->pref &&
513 ds->file[0][ds->len[0] - ds->suff].value == ds->file[1][ds->len[1] - ds->suff].value;
516 for (j = 0; j < 2; j++) {
517 ds->sfile[j] = ds->file[j] + ds->pref;
518 ds->slen[j] = ds->len[j] - ds->pref - ds->suff;
519 for (i = 0; i <= ds->slen[j]; i++)
520 ds->sfile[j][i].serial = i;
525 equiv(struct line *a, int n, struct line *b, int m, int *c)
530 while (i <= n && j <= m) {
531 if (a[i].value < b[j].value)
533 else if (a[i].value == b[j].value)
544 while (b[j + 1].value == b[j].value) {
552 /* Code taken from ping.c */
561 do { /* newton was a stinker */
566 } while ((x - y) > 1 || (x - y) < -1);
572 stone(struct got_diff_state *ds, int *a, int n, int *b, int *c, int flags)
575 int oldc, tc, oldl, sq;
576 u_int numtries, bound;
579 if (flags & D_MINIMAL)
583 bound = MAXIMUM(256, sq);
587 c[0] = newcand(ds, 0, 0, 0, &error);
590 for (i = 1; i <= n; i++) {
599 if (y <= ds->clist[oldc].y)
601 l = search(ds, c, k, y);
605 if (ds->clist[c[l]].y <= y)
608 c[l] = newcand(ds, i, y, oldc, &error);
615 c[l] = newcand(ds, i, y, oldc, &error);
621 } while ((y = b[++j]) > 0 && numtries < bound);
627 newcand(struct got_diff_state *ds, int x, int y, int pred, int *errorp)
631 if (ds->clen == ds->clistlen) {
632 ds->clistlen = ds->clistlen * 11 / 10;
633 q = reallocarray(ds->clist, ds->clistlen, sizeof(*ds->clist));
642 q = ds->clist + ds->clen;
651 search(struct got_diff_state *ds, int *c, int k, int y)
655 if (ds->clist[c[k]].y < y) /* quick look for typical case */
663 t = ds->clist[c[l]].y;
675 unravel(struct got_diff_state *ds, int p)
680 for (i = 0; i <= ds->len[0]; i++)
681 ds->J[i] = i <= ds->pref ? i :
682 i > ds->len[0] - ds->suff ? i + ds->len[1] - ds->len[0] : 0;
683 for (q = ds->clist + p; q->y != 0; q = ds->clist + q->pred)
684 ds->J[q->x + ds->pref] = q->y + ds->pref;
688 * Check does double duty:
689 * 1. ferret out any fortuitous correspondences due
690 * to confounding by hashing (which result in "jackpot")
691 * 2. collect random access indexes to the two files
694 check(struct got_diff_state *ds, FILE *f1, FILE *f2, int flags)
696 int i, j, jackpot, c, d;
702 ds->ixold[0] = ds->ixnew[0] = 0;
705 for (i = 1; i <= ds->len[0]; i++) {
707 ds->ixold[i] = ctold += skipline(f1);
710 while (j < ds->J[i]) {
711 ds->ixnew[j] = ctnew += skipline(f2);
714 if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS|D_IGNORECASE)) {
719 * GNU diff ignores a missing newline
720 * in one file for -b or -w.
722 if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) {
723 if (c == EOF && d == '\n') {
726 } else if (c == '\n' && d == EOF) {
733 if ((flags & D_FOLDBLANKS) && isspace(c) &&
739 } while (isspace(c = getc(f1)));
744 } while (isspace(d = getc(f2)));
745 } else if ((flags & D_IGNOREBLANKS)) {
746 while (isspace(c) && c != '\n') {
750 while (isspace(d) && d != '\n') {
755 if (ds->chrtran[c] != ds->chrtran[d]) {
758 if (c != '\n' && c != EOF)
759 ctold += skipline(f1);
760 if (d != '\n' && c != EOF)
761 ctnew += skipline(f2);
764 if (c == '\n' || c == EOF)
771 if ((c = getc(f1)) != (d = getc(f2))) {
774 if (c != '\n' && c != EOF)
775 ctold += skipline(f1);
776 if (d != '\n' && c != EOF)
777 ctnew += skipline(f2);
780 if (c == '\n' || c == EOF)
784 ds->ixold[i] = ctold;
785 ds->ixnew[j] = ctnew;
788 for (; j <= ds->len[1]; j++)
789 ds->ixnew[j] = ctnew += skipline(f2);
792 * fprintf(stderr, "jackpot\n");
796 /* shellsort CACM #201 */
798 sort(struct line *a, int n)
800 struct line *ai, *aim, w;
805 for (j = 1; j <= n; j *= 2)
807 for (m /= 2; m != 0; m /= 2) {
809 for (j = 1; j <= k; j++) {
810 for (ai = &a[j]; ai > a; ai -= m) {
813 break; /* wraparound */
814 if (aim->value > ai[0].value ||
815 (aim->value == ai[0].value &&
816 aim->serial > ai[0].serial))
818 w.value = ai[0].value;
819 ai[0].value = aim->value;
820 aim->value = w.value;
821 w.serial = ai[0].serial;
822 ai[0].serial = aim->serial;
823 aim->serial = w.serial;
830 unsort(struct line *f, int l, int *b)
834 a = calloc(l + 1, sizeof(*a));
837 for (i = 1; i <= l; i++)
838 a[f[i].serial] = f[i].value;
839 for (i = 1; i <= l; i++)
851 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
857 output(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
858 const char *file1, FILE *f1, const char *file2, FILE *f2, int flags)
860 int m, i0, i1, j0, j1;
867 ds->J[m + 1] = ds->len[1] + 1;
868 if (args->diff_format != D_EDIT) {
869 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
870 while (i0 <= m && ds->J[i0] == ds->J[i0 - 1] + 1)
872 j0 = ds->J[i0 - 1] + 1;
874 while (i1 < m && ds->J[i1 + 1] == 0)
876 j1 = ds->J[i1 + 1] - 1;
878 error = change(outfile, ds, args, file1, f1, file2, f2,
879 i0, i1, j0, j1, &flags);
884 for (i0 = m; i0 >= 1; i0 = i1 - 1) {
885 while (i0 >= 1 && ds->J[i0] == ds->J[i0 + 1] - 1 && ds->J[i0] != 0)
887 j0 = ds->J[i0 + 1] - 1;
889 while (i1 > 1 && ds->J[i1 - 1] == 0)
891 j1 = ds->J[i1 - 1] + 1;
893 change(outfile, ds, args, file1, f1, file2, f2, i1, i0,
900 error = change(outfile, ds, args, file1, f1, file2, f2, 1, 0,
901 1, ds->len[1], &flags);
905 if (args->diff_format == D_IFDEF) {
908 if ((c = getc(f1)) == EOF)
910 diff_output(outfile, "%c", c);
914 if (ds->anychange != 0) {
915 if (args->diff_format == D_CONTEXT)
916 dump_context_vec(outfile, ds, args, f1, f2, flags);
917 else if (args->diff_format == D_UNIFIED)
918 dump_unified_vec(outfile, ds, args, f1, f2, flags);
925 range(FILE *outfile, int a, int b, char *separator)
927 diff_output(outfile, "%d", a > b ? b : a);
929 diff_output(outfile, "%s%d", separator, b);
933 uni_range(FILE *outfile, int a, int b)
936 diff_output(outfile, "%d,%d", a, b - a + 1);
938 diff_output(outfile, "%d", b);
940 diff_output(outfile, "%d,0", b);
944 preadline(int fd, size_t rlen, off_t off)
949 line = malloc(rlen + 1);
952 if ((nr = pread(fd, line, rlen, off)) < 0) {
956 if (nr > 0 && line[nr-1] == '\n')
963 ignoreline(char *line)
965 return 0; /* do not ignore any lines */
969 * Indicate that there is a difference between lines a and b of the from file
970 * to get to lines c to d of the to file. If a is greater then b then there
971 * are no lines in the from file involved and this means that there were
972 * lines appended (beginning at b). If c is greater than d then there are
973 * lines missing from the to file.
976 change(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
977 const char *file1, FILE *f1, const char *file2, FILE *f2,
978 int a, int b, int c, int d, int *pflags)
983 if (args->diff_format != D_IFDEF && a > b && c > d)
985 if (args->ignore_pats != NULL) {
987 * All lines in the change, insert, or delete must
988 * match an ignore pattern for the change to be
991 if (a <= b) { /* Changes and deletes. */
992 for (i = a; i <= b; i++) {
993 char *line = preadline(fileno(f1),
994 ds->ixold[i] - ds->ixold[i - 1],
998 if (!ignoreline(line)) {
1005 if (a > b || c <= d) { /* Changes and inserts. */
1006 for (i = c; i <= d; i++) {
1007 char *line = preadline(fileno(f2),
1008 ds->ixnew[i] - ds->ixnew[i - 1],
1012 if (!ignoreline(line)) {
1022 if (*pflags & D_HEADER) {
1023 diff_output(outfile, "%s %s %s\n", args->diffargs, file1, file2);
1024 *pflags &= ~D_HEADER;
1026 if (args->diff_format == D_CONTEXT || args->diff_format == D_UNIFIED) {
1028 * Allocate change records as needed.
1030 if (ds->context_vec_ptr == ds->context_vec_end - 1) {
1031 struct context_vec *cvp;
1033 offset = ds->context_vec_ptr - ds->context_vec_start;
1034 ds->max_context <<= 1;
1035 ds->context_vec_start =
1036 cvp = reallocarray(ds->context_vec_start,
1037 ds->max_context, sizeof(*ds->context_vec_start));
1039 free(ds->context_vec_start);
1042 ds->context_vec_start = cvp;
1043 ds->context_vec_end = ds->context_vec_start +
1045 ds->context_vec_ptr = ds->context_vec_start + offset;
1047 if (ds->anychange == 0) {
1049 * Print the context/unidiff header first time through.
1051 print_header(outfile, ds, args, file1, file2);
1053 } else if (a > ds->context_vec_ptr->b + (2 * args->diff_context) + 1 &&
1054 c > ds->context_vec_ptr->d + (2 * args->diff_context) + 1) {
1056 * If this change is more than 'diff_context' lines from the
1057 * previous change, dump the record and reset it.
1059 if (args->diff_format == D_CONTEXT)
1060 dump_context_vec(outfile, ds, args, f1, f2, *pflags);
1062 dump_unified_vec(outfile, ds, args, f1, f2, *pflags);
1064 ds->context_vec_ptr++;
1065 ds->context_vec_ptr->a = a;
1066 ds->context_vec_ptr->b = b;
1067 ds->context_vec_ptr->c = c;
1068 ds->context_vec_ptr->d = d;
1071 if (ds->anychange == 0)
1073 switch (args->diff_format) {
1078 range(outfile, a, b, ",");
1079 diff_output(outfile, "%c", a > b ? 'a' : c > d ? 'd' : 'c');
1080 if (args->diff_format == D_NORMAL)
1081 range(outfile, c, d, ",");
1082 diff_output(outfile, "\n");
1085 diff_output(outfile, "%c", a > b ? 'a' : c > d ? 'd' : 'c');
1086 range(outfile, a, b, " ");
1087 diff_output(outfile, "\n");
1091 diff_output(outfile, "a%d %d\n", b, d - c + 1);
1093 diff_output(outfile, "d%d %d\n", a, b - a + 1);
1095 /* add changed lines */
1096 diff_output(outfile, "a%d %d\n", b, d - c + 1);
1100 if (args->diff_format == D_NORMAL || args->diff_format == D_IFDEF) {
1101 fetch(outfile, ds, args, ds->ixold, a, b, f1, '<', 1, *pflags);
1102 if (a <= b && c <= d && args->diff_format == D_NORMAL)
1103 diff_output(outfile, "---\n");
1105 i = fetch(outfile, ds, args, ds->ixnew, c, d, f2, args->diff_format == D_NORMAL ? '>' : '\0', 0, *pflags);
1106 if (i != 0 && args->diff_format == D_EDIT) {
1108 * A non-zero return value for D_EDIT indicates that the
1109 * last line printed was a bare dot (".") that has been
1110 * escaped as ".." to prevent ed(1) from misinterpreting
1111 * it. We have to add a substitute command to change this
1112 * back and restart where we left off.
1114 diff_output(outfile, ".\n");
1115 diff_output(outfile, "%ds/.//\n", a + i - 1);
1121 if ((args->diff_format == D_EDIT || args->diff_format == D_REVERSE) && c <= d)
1122 diff_output(outfile, ".\n");
1124 diff_output(outfile, "#endif /* %s */\n", args->ifdefname);
1132 fetch(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
1133 long *f, int a, int b, FILE *lb, int ch, int oldfile, int flags)
1135 int i, j, c, lastc, col, nc;
1138 * When doing #ifdef's, copy down to current line
1139 * if this is the first file, so that stuff makes it to output.
1141 if (args->diff_format == D_IFDEF && oldfile) {
1142 long curpos = ftell(lb);
1143 /* print through if append (a>b), else to (nb: 0 vs 1 orig) */
1144 nc = f[a > b ? b : a - 1] - curpos;
1145 for (i = 0; i < nc; i++)
1146 diff_output(outfile, "%c", getc(lb));
1150 if (args->diff_format == D_IFDEF) {
1152 diff_output(outfile, "#else /* %s%s */\n",
1153 oldfile == 1 ? "!" : "", args->ifdefname);
1156 diff_output(outfile, "#ifndef %s\n", args->ifdefname);
1158 diff_output(outfile, "#ifdef %s\n", args->ifdefname);
1160 ds->inifdef = 1 + oldfile;
1162 for (i = a; i <= b; i++) {
1163 fseek(lb, f[i - 1], SEEK_SET);
1164 nc = f[i] - f[i - 1];
1165 if (args->diff_format != D_IFDEF && ch != '\0') {
1166 diff_output(outfile, "%c", ch);
1167 if (args->Tflag && (args->diff_format == D_NORMAL || args->diff_format == D_CONTEXT
1168 || args->diff_format == D_UNIFIED))
1169 diff_output(outfile, "\t");
1170 else if (args->diff_format != D_UNIFIED)
1171 diff_output(outfile, " ");
1174 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
1175 if ((c = getc(lb)) == EOF) {
1176 if (args->diff_format == D_EDIT || args->diff_format == D_REVERSE ||
1177 args->diff_format == D_NREVERSE)
1178 warnx("No newline at end of file");
1180 diff_output(outfile, "\n\\ No newline at end of "
1184 if (c == '\t' && (flags & D_EXPANDTABS)) {
1186 diff_output(outfile, " ");
1187 } while (++col & 7);
1189 if (args->diff_format == D_EDIT && j == 1 && c == '\n'
1192 * Don't print a bare "." line
1193 * since that will confuse ed(1).
1194 * Print ".." instead and return,
1195 * giving the caller an offset
1196 * from which to restart.
1198 diff_output(outfile, ".\n");
1201 diff_output(outfile, "%c", c);
1210 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
1213 readhash(struct got_diff_state *ds, FILE *f, int flags)
1220 if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) == 0) {
1221 if (flags & D_IGNORECASE)
1222 for (i = 0; (t = getc(f)) != '\n'; i++) {
1228 sum = sum * 127 + ds->chrtran[t];
1231 for (i = 0; (t = getc(f)) != '\n'; i++) {
1237 sum = sum * 127 + t;
1241 switch (t = getc(f)) {
1250 if (space && (flags & D_IGNOREBLANKS) == 0) {
1254 sum = sum * 127 + ds->chrtran[t];
1268 * There is a remote possibility that we end up with a zero sum.
1269 * Zero is used as an EOF marker, so return 1 instead.
1271 return (sum == 0 ? 1 : sum);
1277 unsigned char buf[BUFSIZ];
1284 cnt = fread(buf, 1, sizeof(buf), f);
1285 return (memchr(buf, '\0', cnt) == NULL);
1288 #define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0)
1291 match_function(struct got_diff_state *ds, const long *f, int pos, FILE *fp)
1293 unsigned char buf[FUNCTION_CONTEXT_SIZE];
1295 int last = ds->lastline;
1299 while (pos > last) {
1300 fseek(fp, f[pos - 1], SEEK_SET);
1301 nc = f[pos] - f[pos - 1];
1302 if (nc >= sizeof(buf))
1303 nc = sizeof(buf) - 1;
1304 nc = fread(buf, 1, nc, fp);
1307 buf[strcspn(buf, "\n")] = '\0';
1308 if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
1309 if (begins_with(buf, "private:")) {
1311 state = " (private)";
1312 } else if (begins_with(buf, "protected:")) {
1314 state = " (protected)";
1315 } else if (begins_with(buf, "public:")) {
1317 state = " (public)";
1319 strlcpy(ds->lastbuf, buf, sizeof ds->lastbuf);
1321 strlcat(ds->lastbuf, state,
1322 sizeof ds->lastbuf);
1323 ds->lastmatchline = pos;
1330 return ds->lastmatchline > 0 ? ds->lastbuf : NULL;
1333 /* dump accumulated "context" diff changes */
1335 dump_context_vec(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
1336 FILE *f1, FILE *f2, int flags)
1338 struct context_vec *cvp = ds->context_vec_start;
1339 int lowa, upb, lowc, upd, do_output;
1343 if (ds->context_vec_start > ds->context_vec_ptr)
1346 b = d = 0; /* gcc */
1347 lowa = MAXIMUM(1, cvp->a - args->diff_context);
1348 upb = MINIMUM(ds->len[0], ds->context_vec_ptr->b + args->diff_context);
1349 lowc = MAXIMUM(1, cvp->c - args->diff_context);
1350 upd = MINIMUM(ds->len[1], ds->context_vec_ptr->d + args->diff_context);
1352 diff_output(outfile, "***************");
1353 if ((flags & D_PROTOTYPE)) {
1354 f = match_function(ds, ds->ixold, lowa-1, f1);
1356 diff_output(outfile, " %s", f);
1358 diff_output(outfile, "\n*** ");
1359 range(outfile, lowa, upb, ",");
1360 diff_output(outfile, " ****\n");
1363 * Output changes to the "old" file. The first loop suppresses
1364 * output if there were no changes to the "old" file (we'll see
1365 * the "old" lines as context in the "new" list).
1368 for (; cvp <= ds->context_vec_ptr; cvp++)
1369 if (cvp->a <= cvp->b) {
1370 cvp = ds->context_vec_start;
1375 while (cvp <= ds->context_vec_ptr) {
1381 if (a <= b && c <= d)
1384 ch = (a <= b) ? 'd' : 'a';
1387 fetch(outfile, ds, args, ds->ixold, lowa, b, f1, ' ', 0, flags);
1389 fetch(outfile, ds, args, ds->ixold, lowa, a - 1, f1, ' ', 0, flags);
1390 fetch(outfile, ds, args, ds->ixold, a, b, f1,
1391 ch == 'c' ? '!' : '-', 0, flags);
1396 fetch(outfile, ds, args, ds->ixold, b + 1, upb, f1, ' ', 0, flags);
1398 /* output changes to the "new" file */
1399 diff_output(outfile, "--- ");
1400 range(outfile, lowc, upd, ",");
1401 diff_output(outfile, " ----\n");
1404 for (cvp = ds->context_vec_start; cvp <= ds->context_vec_ptr; cvp++)
1405 if (cvp->c <= cvp->d) {
1406 cvp = ds->context_vec_start;
1411 while (cvp <= ds->context_vec_ptr) {
1417 if (a <= b && c <= d)
1420 ch = (a <= b) ? 'd' : 'a';
1423 fetch(outfile, ds, args, ds->ixnew, lowc, d, f2, ' ', 0, flags);
1425 fetch(outfile, ds, args, ds->ixnew, lowc, c - 1, f2, ' ', 0, flags);
1426 fetch(outfile, ds, args, ds->ixnew, c, d, f2,
1427 ch == 'c' ? '!' : '+', 0, flags);
1432 fetch(outfile, ds, args, ds->ixnew, d + 1, upd, f2, ' ', 0, flags);
1434 ds->context_vec_ptr = ds->context_vec_start - 1;
1437 /* dump accumulated "unified" diff changes */
1439 dump_unified_vec(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
1440 FILE *f1, FILE *f2, int flags)
1442 struct context_vec *cvp = ds->context_vec_start;
1443 int lowa, upb, lowc, upd;
1447 if (ds->context_vec_start > ds->context_vec_ptr)
1450 b = d = 0; /* gcc */
1451 lowa = MAXIMUM(1, cvp->a - args->diff_context);
1452 upb = MINIMUM(ds->len[0], ds->context_vec_ptr->b + args->diff_context);
1453 lowc = MAXIMUM(1, cvp->c - args->diff_context);
1454 upd = MINIMUM(ds->len[1], ds->context_vec_ptr->d + args->diff_context);
1456 diff_output(outfile, "@@ -");
1457 uni_range(outfile, lowa, upb);
1458 diff_output(outfile, " +");
1459 uni_range(outfile, lowc, upd);
1460 diff_output(outfile, " @@");
1461 if ((flags & D_PROTOTYPE)) {
1462 f = match_function(ds, ds->ixold, lowa-1, f1);
1464 diff_output(outfile, " %s", f);
1466 diff_output(outfile, "\n");
1469 * Output changes in "unified" diff format--the old and new lines
1470 * are printed together.
1472 for (; cvp <= ds->context_vec_ptr; cvp++) {
1479 * c: both new and old changes
1480 * d: only changes in the old file
1481 * a: only changes in the new file
1483 if (a <= b && c <= d)
1486 ch = (a <= b) ? 'd' : 'a';
1490 fetch(outfile, ds, args, ds->ixold, lowa, a - 1, f1, ' ', 0, flags);
1491 fetch(outfile, ds, args, ds->ixold, a, b, f1, '-', 0, flags);
1492 fetch(outfile, ds, args, ds->ixnew, c, d, f2, '+', 0, flags);
1495 fetch(outfile, ds, args, ds->ixold, lowa, a - 1, f1, ' ', 0, flags);
1496 fetch(outfile, ds, args, ds->ixold, a, b, f1, '-', 0, flags);
1499 fetch(outfile, ds, args, ds->ixnew, lowc, c - 1, f2, ' ', 0, flags);
1500 fetch(outfile, ds, args, ds->ixnew, c, d, f2, '+', 0, flags);
1506 fetch(outfile, ds, args, ds->ixnew, d + 1, upd, f2, ' ', 0, flags);
1508 ds->context_vec_ptr = ds->context_vec_start - 1;
1512 print_header(FILE *outfile, struct got_diff_state *ds, struct got_diff_args *args,
1513 const char *file1, const char *file2)
1515 if (args->label[0] != NULL)
1516 diff_output(outfile, "%s %s\n", args->diff_format == D_CONTEXT ? "***" : "---",
1519 diff_output(outfile, "%s %s\t%s", args->diff_format == D_CONTEXT ? "***" : "---",
1520 file1, ctime(&ds->stb1.st_mtime));
1521 if (args->label[1] != NULL)
1522 diff_output(outfile, "%s %s\n", args->diff_format == D_CONTEXT ? "---" : "+++",
1525 diff_output(outfile, "%s %s\t%s", args->diff_format == D_CONTEXT ? "---" : "+++",
1526 file2, ctime(&ds->stb2.st_mtime));