1 /* $OpenBSD: diff3.c,v 1.41 2016/10/18 21:06:52 millert Exp $ */
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41 * modification, are permitted provided that the following conditions
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64 * @(#)diff3.c 8.1 (Berkeley) 6/6/93
68 #include <sys/queue.h>
79 #include "got_error.h"
80 #include "got_opentemp.h"
81 #include "got_object.h"
85 #include "got_lib_diff.h"
89 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
92 /* diff3 - 3-way differential file comparison */
94 /* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
96 * d13 = diff report on f1 vs f3
97 * d23 = diff report on f2 vs f3
98 * f1, f2, f3 the 3 files
99 * if changes in f1 overlap with changes in f3, m1 and m3 are used
100 * to mark the overlaps; otherwise, the file names f1 and f3 are used
101 * (only for options E and X).
105 * "from" is first in range of changed lines; "to" is last+1
106 * from=to=line after point of insertion for added lines.
125 * "de" is used to gather editing scripts. These are later spewed out
126 * in reverse order. Its first element must be all zero, the "new"
127 * component of "de" contains line positions or byte positions
128 * depending on when you look (!?). Array overlap indicates which
129 * sections in "de" correspond to lines that are different in all
136 int cline[3]; /* # of the last-read line in each file (0-2) */
139 * the latest known correspondence between line numbers of the 3 files
140 * is stored in last[1-3];
143 char f1mark[PATH_MAX], f3mark[PATH_MAX]; /* markers for -E and -X */
151 static const struct got_error *duplicate(int *, struct range *, struct range *,
152 struct diff3_state *);
153 static const struct got_error *edit(struct diff *, int, int *,
154 struct diff3_state *);
155 static const struct got_error *getchange(char **, FILE *, struct diff3_state *);
156 static const struct got_error *get_line(char **, FILE *, size_t *,
157 struct diff3_state *);
158 static int number(char **);
159 static const struct got_error *readin(size_t *, char *, struct diff **,
160 struct diff3_state *);
161 static int ed_patch_lines(struct rcs_lines *, struct rcs_lines *);
162 static const struct got_error *skip(int *, int, int, struct diff3_state *);
163 static const struct got_error *edscript(int, struct diff3_state *);
164 static const struct got_error *merge(size_t, size_t, struct diff3_state *);
165 static const struct got_error *prange(struct range *, struct diff3_state *);
166 static const struct got_error *repos(int, struct diff3_state *);
167 static const struct got_error *increase(struct diff3_state *);
168 static const struct got_error *diff3_internal(char *, char *, char *,
169 char *, char *, const char *, const char *, struct diff3_state *,
170 const char *, const char *);
172 static const struct got_error *
173 diff_output(BUF *diffbuf, const char *fmt, ...)
175 const struct got_error *err = NULL;
182 i = vasprintf(&str, fmt, vap);
185 return got_error_from_errno("vasprintf");
186 err = buf_append(&newsize, diffbuf, str, strlen(str));
191 static const struct got_error*
192 diffreg(BUF **d, const char *path1, const char *path2)
194 const struct got_error *err = NULL;
195 FILE *f1 = NULL, *f2 = NULL, *outfile = NULL;
196 char *outpath = NULL;
197 struct got_diff_state ds;
198 struct got_diff_args args;
203 f1 = fopen(path1, "r");
205 err = got_error_from_errno2("fopen", path1);
208 f2 = fopen(path2, "r");
210 err = got_error_from_errno2("fopen", path2);
214 err = got_opentemp_named(&outpath, &outfile, "/tmp/got-diffreg");
218 memset(&ds, 0, sizeof(ds));
219 /* XXX should stat buffers be passed in args instead of ds? */
220 if (stat(path1, &ds.stb1) == -1) {
221 err = got_error_from_errno2("stat", path1);
224 if (stat(path2, &ds.stb2) == -1) {
225 err = got_error_from_errno2("stat", path2);
229 memset(&args, 0, sizeof(args));
230 args.diff_format = D_NORMAL;
233 args.diff_context = 0;
235 err = got_diffreg(&res, f1, f2, D_FORCEASCII, &args, &ds,
240 if (fflush(outfile) != 0) {
241 err = got_error_from_errno2("fflush", outpath);
245 err = buf_load(d, outpath);
251 if (outfile && fclose(outfile) != 0 && err == NULL)
252 err = got_error_from_errno("fclose");
253 if (f1 && fclose(f1) != 0 && err == NULL)
254 err = got_error_from_errno("fclose");
255 if (f2 && fclose(f2) != 0 && err == NULL)
256 err = got_error_from_errno("fclose");
263 const struct got_error *
264 got_merge_diff3(int *overlapcnt, int outfd, const char *p1, const char *p2,
265 const char *p3, const char *label1, const char *label3)
267 const struct got_error *err = NULL;
268 char *dp13, *dp23, *path1, *path2, *path3;
269 BUF *b1, *b2, *b3, *d1, *d2, *diffb;
270 u_char *data, *patch;
272 struct wklhead temp_files;
273 struct diff3_state *d3s;
278 SLIST_INIT(&temp_files);
280 d3s = calloc(1, sizeof(*d3s));
282 return got_error_from_errno("calloc");
284 b1 = b2 = b3 = d1 = d2 = diffb = NULL;
285 dp13 = dp23 = path1 = path2 = path3 = NULL;
288 err = buf_load(&b1, p1);
291 err = buf_load(&b2, p2);
294 err = buf_load(&b3, p3);
298 err = buf_alloc(&diffb, 128);
302 if (asprintf(&path1, "/tmp/got-diff1.XXXXXXXX") == -1) {
303 err = got_error_from_errno("asprintf");
306 if (asprintf(&path2, "/tmp/got-diff2.XXXXXXXX") == -1) {
307 err = got_error_from_errno("asprintf");
310 if (asprintf(&path3, "/tmp/got-diff3.XXXXXXXX") == -1) {
311 err = got_error_from_errno("asprintf");
315 err = buf_write_stmp(b1, path1, &temp_files);
318 err = buf_write_stmp(b2, path2, &temp_files);
321 err = buf_write_stmp(b3, path3, &temp_files);
328 err = diffreg(&d1, path1, path3);
335 err = diffreg(&d2, path2, path3);
342 if (asprintf(&dp13, "/tmp/got-d13.XXXXXXXXXX") == -1) {
343 err = got_error_from_errno("asprintf");
346 err = buf_write_stmp(d1, dp13, &temp_files);
353 if (asprintf(&dp23, "/tmp/got-d23.XXXXXXXXXX") == -1) {
354 err = got_error_from_errno("asprintf");
357 err = buf_write_stmp(d2, dp23, &temp_files);
364 d3s->diffbuf = diffb;
365 err = diff3_internal(dp13, dp23, path1, path2, path3,
366 label1, label3, d3s, label1, label3);
373 plen = buf_len(diffb);
374 patch = buf_release(diffb);
376 data = buf_release(b1);
378 diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines);
397 worklist_clean(&temp_files, worklist_unlink);
399 for (i = 0; i < nitems(d3s->fp); i++) {
400 if (d3s->fp[i] && fclose(d3s->fp[i]) != 0 && err == NULL)
401 err = got_error_from_errno("fclose");
403 if (err == NULL && diffb) {
404 if (buf_write_fd(diffb, outfd) < 0)
405 err = got_error_from_errno("buf_write_fd");
406 *overlapcnt = d3s->overlapcnt;
413 static const struct got_error *
414 diff3_internal(char *dp13, char *dp23, char *path1, char *path2, char *path3,
415 const char *fmark, const char *rmark, struct diff3_state *d3s,
416 const char *label1, const char *label3)
418 const struct got_error *err = NULL;
422 i = snprintf(d3s->f1mark, sizeof(d3s->f1mark),
423 "%s %s", GOT_DIFF_CONFLICT_MARKER_BEGIN, label1);
424 if (i < 0 || i >= (int)sizeof(d3s->f1mark))
425 return got_error(GOT_ERR_NO_SPACE);
427 i = snprintf(d3s->f3mark, sizeof(d3s->f3mark),
428 "%s %s", GOT_DIFF_CONFLICT_MARKER_END, label3);
429 if (i < 0 || i >= (int)sizeof(d3s->f3mark))
430 return got_error(GOT_ERR_NO_SPACE);
436 err = readin(&m, dp13, &d3s->d13, d3s);
439 err = readin(&n, dp23, &d3s->d23, d3s);
443 if ((d3s->fp[0] = fopen(path1, "r")) == NULL)
444 return got_error_from_errno2("fopen", path1);
445 if ((d3s->fp[1] = fopen(path2, "r")) == NULL)
446 return got_error_from_errno2("fopen", path2);
447 if ((d3s->fp[2] = fopen(path3, "r")) == NULL)
448 return got_error_from_errno2("fopen", path3);
450 return merge(m, n, d3s);
454 ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
457 struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after;
458 int start, end, i, lineno;
461 dlp = TAILQ_FIRST(&(dlines->l_lines));
462 lp = TAILQ_FIRST(&(plines->l_lines));
465 for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
466 lp = TAILQ_NEXT(lp, l_list)) {
467 /* Skip blank lines */
471 /* NUL-terminate line buffer for strtol() safety. */
472 tmp = lp->l_line[lp->l_len - 1];
473 lp->l_line[lp->l_len - 1] = '\0';
475 /* len - 1 is NUL terminator so we use len - 2 for 'op' */
476 op = lp->l_line[lp->l_len - 2];
477 start = (int)strtol(lp->l_line, &ep, 10);
479 /* Restore the last byte of the buffer */
480 lp->l_line[lp->l_len - 1] = tmp;
483 if (start > dlines->l_nblines ||
484 start < 0 || *ep != 'a')
486 } else if (op == 'c') {
487 if (start > dlines->l_nblines ||
488 start < 0 || (*ep != ',' && *ep != 'c'))
493 end = (int)strtol(ep, &ep, 10);
494 if (end < 0 || *ep != 'c')
505 if (dlp->l_lineno == start)
507 if (dlp->l_lineno > start) {
508 dlp = TAILQ_PREV(dlp, tqh, l_list);
509 } else if (dlp->l_lineno < start) {
510 ndlp = TAILQ_NEXT(dlp, l_list);
511 if (ndlp->l_lineno > start)
522 insert_after = TAILQ_PREV(dlp, tqh, l_list);
523 for (i = 0; i <= (end - start); i++) {
524 ndlp = TAILQ_NEXT(dlp, l_list);
525 TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
531 if (op == 'a' || op == 'c') {
534 lp = TAILQ_NEXT(lp, l_list);
538 if (lp->l_len == 2 &&
539 lp->l_line[0] == '.' &&
540 lp->l_line[1] == '\n')
543 TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
544 TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
548 lp->l_lineno = start;
554 * always resort lines as the markers might be put at the
555 * same line as we first started editing.
558 TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
559 sort->l_lineno = lineno++;
560 dlines->l_nblines = lineno - 1;
567 * Pick up the line numbers of all changes from one change file.
568 * (This puts the numbers in a vector, which is not strictly necessary,
569 * since the vector is processed in one sequential pass.
570 * The vector could be optimized out of existence)
572 static const struct got_error *
573 readin(size_t *n, char *name, struct diff **dd, struct diff3_state *d3s)
575 const struct got_error *err = NULL;
583 f = fopen(name, "r");
585 return got_error_from_errno2("fopen", name);
586 err = getchange(&p, f, d3s);
589 for (i = 0; p; i++) {
590 if (i >= d3s->szchanges - 1) {
612 (*dd)[i].old.from = a;
614 (*dd)[i].new.from = c;
617 err = getchange(&p, f, d3s);
623 (*dd)[i].old.from = (*dd)[i - 1].old.to;
624 (*dd)[i].new.from = (*dd)[i - 1].new.to;
627 if (fclose(f) != 0 && err == NULL)
628 err = got_error_from_errno("fclose");
640 while (isdigit((unsigned char)(**lc)))
641 nn = nn*10 + *(*lc)++ - '0';
646 static const struct got_error *
647 getchange(char **line, FILE *b, struct diff3_state *d3s)
649 const struct got_error *err = NULL;
653 if (*line && isdigit((unsigned char)(*line)[0]))
655 err = get_line(line, b, NULL, d3s);
663 static const struct got_error *
664 get_line(char **ret, FILE *b, size_t *n, struct diff3_state *d3s)
666 const struct got_error *err = NULL;
674 len = getline(&cp, &size, b);
677 err = got_error_from_errno("getline");
681 if (cp[len - 1] != '\n') {
683 if (len + 1 > size) {
684 new = realloc(cp, len + 1);
686 err = got_error_from_errno("realloc");
696 *ret = d3s->buf = cp;
705 static const struct got_error *
706 merge(size_t m1, size_t m2, struct diff3_state *d3s)
708 const struct got_error *err = NULL;
709 struct diff *d1, *d2;
716 t1 = (d1 < d3s->d13 + m1);
717 t2 = (d2 < d3s->d23 + m2);
721 /* first file is different from others */
722 if (!t2 || (t1 && d1->new.to < d2->new.from)) {
723 /* stuff peculiar to 1st file */
728 /* second file is different from others */
729 if (!t1 || (t2 && d2->new.to < d1->new.from)) {
735 * Merge overlapping changes in first file
736 * this happens after extension (see below).
738 if (d1 + 1 < d3s->d13 + m1 && d1->new.to >= d1[1].new.from) {
739 d1[1].old.from = d1->old.from;
740 d1[1].new.from = d1->new.from;
745 /* merge overlapping changes in second */
746 if (d2 + 1 < d3s->d23 + m2 && d2->new.to >= d2[1].new.from) {
747 d2[1].old.from = d2->old.from;
748 d2[1].new.from = d2->new.from;
752 /* stuff peculiar to third file or different in all */
753 if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
754 err = duplicate(&dpl, &d1->old, &d2->old, d3s);
759 * dpl = 0 means all files differ
760 * dpl = 1 means files 1 and 2 identical
762 err = edit(d1, dpl, &j, d3s);
771 * Overlapping changes from file 1 and 2; extend changes
772 * appropriately to make them coincide.
774 if (d1->new.from < d2->new.from) {
775 d2->old.from -= d2->new.from - d1->new.from;
776 d2->new.from = d1->new.from;
777 } else if (d2->new.from < d1->new.from) {
778 d1->old.from -= d1->new.from - d2->new.from;
779 d1->new.from = d2->new.from;
781 if (d1->new.to > d2->new.to) {
782 d2->old.to += d1->new.to - d2->new.to;
783 d2->new.to = d1->new.to;
784 } else if (d2->new.to > d1->new.to) {
785 d1->old.to += d2->new.to - d1->new.to;
786 d1->new.to = d2->new.to;
790 return (edscript(j, d3s));
794 * print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
796 static const struct got_error *
797 prange(struct range *rold, struct diff3_state *d3s)
799 const struct got_error *err = NULL;
801 if (rold->to <= rold->from) {
802 err = diff_output(d3s->diffbuf, "%da\n", rold->from - 1);
806 err = diff_output(d3s->diffbuf, "%d", rold->from);
809 if (rold->to > rold->from + 1) {
810 err = diff_output(d3s->diffbuf, ",%d", rold->to - 1);
814 err = diff_output(d3s->diffbuf, "c\n");
822 /* skip to just before line number from in file "i". */
823 static const struct got_error *
824 skip(int *nskipped, int i, int from, struct diff3_state *d3s)
826 const struct got_error *err = NULL;
831 for (n = 0; d3s->cline[i] < from - 1; n += len) {
832 err = get_line(&line, d3s->fp[i], &len, d3s);
842 * Set *dpl to 1 or 0 according as the old range (in file 1) contains exactly
843 * the same data as the new range (in file 2).
845 static const struct got_error *
846 duplicate(int *dpl, struct range *r1, struct range *r2, struct diff3_state *d3s)
848 const struct got_error *err = NULL;
855 if (r1->to - r1->from != r2->to - r2->from)
858 err = skip(&nskipped, 0, r1->from, d3s);
861 err = skip(&nskipped, 1, r2->from, d3s);
865 for (nline = 0; nline < r1->to - r1->from; nline++) {
867 c = getc(d3s->fp[0]);
869 return got_ferror(d3s->fp[0], GOT_ERR_EOF);
870 d = getc(d3s->fp[1]);
872 return got_ferror(d3s->fp[1], GOT_ERR_EOF);
875 return repos(nchar, d3s);
878 err = repos(nchar, d3s);
885 static const struct got_error *
886 repos(int nchar, struct diff3_state *d3s)
890 for (i = 0; i < 2; i++) {
891 if (fseek(d3s->fp[i], (long)-nchar, SEEK_CUR) == -1)
892 return got_ferror(d3s->fp[i], GOT_ERR_IO);
899 * collect an editing script for later regurgitation
901 static const struct got_error *
902 edit(struct diff *diff, int fdup, int *j, struct diff3_state *d3s)
904 const struct got_error *err = NULL;
907 if (((fdup + 1) & 3) == 0)
910 d3s->overlap[*j] = !fdup;
913 d3s->de[*j].old.from = diff->old.from;
914 d3s->de[*j].old.to = diff->old.to;
915 err = skip(&nskipped, 2, diff->new.from, d3s);
918 d3s->de[*j].new.from = d3s->de[*j - 1].new.to + nskipped;
919 err = skip(&nskipped, 2, diff->new.to, d3s);
920 d3s->de[*j].new.to = d3s->de[*j].new.from + nskipped;
925 static const struct got_error *
926 edscript(int n, struct diff3_state *d3s)
928 const struct got_error *err = NULL;
930 char block[BUFSIZ+1];
933 if (!d3s->overlap[n]) {
934 err = prange(&d3s->de[n].old, d3s);
938 err = diff_output(d3s->diffbuf, "%da\n%s\n",
939 d3s->de[n].old.to -1, GOT_DIFF_CONFLICT_MARKER_SEP);
943 if (fseek(d3s->fp[2], (long)d3s->de[n].new.from, SEEK_SET)
945 return got_error_from_errno("fseek");
946 k = d3s->de[n].new.to - d3s->de[n].new.from;
947 for (; k > 0; k -= len) {
948 len = k > BUFSIZ ? BUFSIZ : k;
949 if (fread(block, 1, len, d3s->fp[2]) != (size_t)len)
950 return got_ferror(d3s->fp[2], GOT_ERR_IO);
952 err = diff_output(d3s->diffbuf, "%s", block);
957 if (!d3s->overlap[n]) {
958 err = diff_output(d3s->diffbuf, ".\n");
962 err = diff_output(d3s->diffbuf, "%s\n.\n", d3s->f3mark);
965 err = diff_output(d3s->diffbuf, "%da\n%s\n.\n",
966 d3s->de[n].old.from - 1, d3s->f1mark);
975 static const struct got_error *
976 increase(struct diff3_state *d3s)
982 /* are the memset(3) calls needed? */
983 newsz = d3s->szchanges == 0 ? 64 : 2 * d3s->szchanges;
984 incr = newsz - d3s->szchanges;
986 d = reallocarray(d3s->d13, newsz, sizeof(*d3s->d13));
988 return got_error_from_errno("reallocarray");
990 memset(d3s->d13 + d3s->szchanges, 0, incr * sizeof(*d3s->d13));
992 d = reallocarray(d3s->d23, newsz, sizeof(*d3s->d23));
994 return got_error_from_errno("reallocarray");
996 memset(d3s->d23 + d3s->szchanges, 0, incr * sizeof(*d3s->d23));
998 d = reallocarray(d3s->de, newsz, sizeof(*d3s->de));
1000 return got_error_from_errno("reallocarray");
1002 memset(d3s->de + d3s->szchanges, 0, incr * sizeof(*d3s->de));
1004 s = reallocarray(d3s->overlap, newsz, sizeof(*d3s->overlap));
1006 return got_error_from_errno("reallocarray");
1008 memset(d3s->overlap + d3s->szchanges, 0, incr * sizeof(*d3s->overlap));
1009 d3s->szchanges = newsz;