/* $OpenBSD: diff3.c,v 1.41 2016/10/18 21:06:52 millert Exp $ */
/*
* Copyright (C) Caldera International Inc. 2001-2002.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code and documentation must retain the above
* copyright notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed or owned by Caldera
* International, Inc.
* 4. Neither the name of Caldera International, Inc. nor the names of other
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
* INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
* INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)diff3.c 8.1 (Berkeley) 6/6/93
*/
#include <sys/stat.h>
#include <sys/queue.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "got_error.h"
#include "got_opentemp.h"
#include "got_object.h"
#include "buf.h"
#include "rcsutil.h"
#include "got_lib_diff.h"
#ifndef nitems
#define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
#endif
/* diff3 - 3-way differential file comparison */
/* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]
*
* d13 = diff report on f1 vs f3
* d23 = diff report on f2 vs f3
* f1, f2, f3 the 3 files
* if changes in f1 overlap with changes in f3, m1 and m3 are used
* to mark the overlaps; otherwise, the file names f1 and f3 are used
* (only for options E and X).
*/
/*
* "from" is first in range of changed lines; "to" is last+1
* from=to=line after point of insertion for added lines.
*/
struct line_range {
int from;
int to;
};
struct off_range {
off_t from;
off_t to;
};
struct diff {
struct line_range old;
struct line_range new;
struct off_range oldo;
struct off_range newo;
};
struct diff3_state {
size_t szchanges;
struct diff *d13;
struct diff *d23;
/*
* "de" is used to gather editing scripts. These are later spewed out
* in reverse order. Its first element must be all zero, the "new"
* component of "de" contains line positions, and "oldo" and "newo"
* components contain byte positions.
* Array overlap indicates which sections in "de" correspond to lines
* that are different in all three files.
*/
struct diff *de;
char *overlap;
int overlapcnt;
FILE *fp[3];
int cline[3]; /* # of the last-read line in each file (0-2) */
/*
* the latest known correspondence between line numbers of the 3 files
* is stored in last[1-3];
*/
int last[4];
char f1mark[PATH_MAX];
char f2mark[PATH_MAX];
char f3mark[PATH_MAX];
char *buf;
BUF *diffbuf;
};
static const struct got_error *duplicate(int *, int, struct line_range *,
struct line_range *, struct diff3_state *);
static const struct got_error *edit(struct diff *, int, int *,
struct diff3_state *);
static const struct got_error *getchange(char **, FILE *, struct diff3_state *);
static const struct got_error *get_line(char **, FILE *, size_t *,
struct diff3_state *);
static int number(char **);
static const struct got_error *readin(size_t *, char *, struct diff **,
struct diff3_state *);
static int ed_patch_lines(struct rcs_lines *, struct rcs_lines *);
static const struct got_error *skip(size_t *, int, int, struct diff3_state *);
static const struct got_error *edscript(int, struct diff3_state *);
static const struct got_error *merge(size_t, size_t, struct diff3_state *);
static const struct got_error *prange(struct line_range *,
struct diff3_state *);
static const struct got_error *repos(int, struct diff3_state *);
static const struct got_error *increase(struct diff3_state *);
static const struct got_error *diff3_internal(char *, char *, char *,
char *, char *, const char *, const char *, struct diff3_state *,
const char *, const char *, const char *);
static const struct got_error *
diff_output(BUF *diffbuf, const char *fmt, ...)
{
const struct got_error *err = NULL;
va_list vap;
int i;
char *str;
size_t newsize;
va_start(vap, fmt);
i = vasprintf(&str, fmt, vap);
va_end(vap);
if (i == -1)
return got_error_from_errno("vasprintf");
err = buf_append(&newsize, diffbuf, str, strlen(str));
free(str);
return err;
}
static const struct got_error*
diffreg(BUF **d, const char *path1, const char *path2,
enum got_diff_algorithm diff_algo)
{
const struct got_error *err = NULL;
FILE *f1 = NULL, *f2 = NULL, *outfile = NULL;
char *outpath = NULL;
struct got_diffreg_result *diffreg_result = NULL;
*d = NULL;
f1 = fopen(path1, "re");
if (f1 == NULL) {
err = got_error_from_errno2("fopen", path1);
goto done;
}
f2 = fopen(path2, "re");
if (f1 == NULL) {
err = got_error_from_errno2("fopen", path2);
goto done;
}
err = got_opentemp_named(&outpath, &outfile,
GOT_TMPDIR_STR "/got-diffreg");
if (err)
goto done;
err = got_diffreg(&diffreg_result, f1, f2, diff_algo, 0, 0);
if (err)
goto done;
if (diffreg_result) {
struct diff_result *diff_result = diffreg_result->result;
int atomizer_flags = (diff_result->left->atomizer_flags |
diff_result->right->atomizer_flags);
if ((atomizer_flags & DIFF_ATOMIZER_FOUND_BINARY_DATA)) {
err = got_error(GOT_ERR_FILE_BINARY);
goto done;
}
}
err = got_diffreg_output(NULL, NULL, diffreg_result, 1, 1, "", "",
GOT_DIFF_OUTPUT_EDSCRIPT, 0, outfile);
if (err)
goto done;
if (fflush(outfile) != 0) {
err = got_error_from_errno2("fflush", outpath);
goto done;
}
if (fseek(outfile, 0L, SEEK_SET) == -1) {
err = got_ferror(outfile, GOT_ERR_IO);
goto done;
}
err = buf_load(d, outfile);
done:
if (outpath) {
if (unlink(outpath) == -1 && err == NULL)
err = got_error_from_errno2("unlink", outpath);
free(outpath);
}
if (outfile && fclose(outfile) == EOF && err == NULL)
err = got_error_from_errno("fclose");
if (f1 && fclose(f1) == EOF && err == NULL)
err = got_error_from_errno("fclose");
if (f2 && fclose(f2) == EOF && err == NULL)
err = got_error_from_errno("fclose");
return err;
}
/*
* For merge(1).
*/
const struct got_error *
got_merge_diff3(int *overlapcnt, int outfd, FILE *f1, FILE *f2,
FILE *f3, const char *label1, const char *label2, const char *label3,
enum got_diff_algorithm diff_algo)
{
const struct got_error *err = NULL;
char *dp13, *dp23, *path1, *path2, *path3;
BUF *b1, *b2, *b3, *d1, *d2, *diffb;
u_char *data, *patch;
size_t dlen, plen, i;
struct diff3_state *d3s;
*overlapcnt = 0;
d3s = calloc(1, sizeof(*d3s));
if (d3s == NULL)
return got_error_from_errno("calloc");
b1 = b2 = b3 = d1 = d2 = diffb = NULL;
dp13 = dp23 = path1 = path2 = path3 = NULL;
data = patch = NULL;
err = buf_load(&b1, f1);
if (err)
goto out;
err = buf_load(&b2, f2);
if (err)
goto out;
err = buf_load(&b3, f3);
if (err)
goto out;
err = buf_alloc(&diffb, 128);
if (err)
goto out;
if (asprintf(&path1, GOT_TMPDIR_STR "/got-diff1.XXXXXXXX") == -1) {
err = got_error_from_errno("asprintf");
goto out;
}
if (asprintf(&path2, GOT_TMPDIR_STR "/got-diff2.XXXXXXXX") == -1) {
err = got_error_from_errno("asprintf");
goto out;
}
if (asprintf(&path3, GOT_TMPDIR_STR "/got-diff3.XXXXXXXX") == -1) {
err = got_error_from_errno("asprintf");
goto out;
}
err = buf_write_stmp(b1, path1);
if (err)
goto out;
err = buf_write_stmp(b2, path2);
if (err)
goto out;
err = buf_write_stmp(b3, path3);
if (err)
goto out;
buf_free(b2);
b2 = NULL;
err = diffreg(&d1, path1, path3, diff_algo);
if (err) {
buf_free(diffb);
diffb = NULL;
goto out;
}
err = diffreg(&d2, path2, path3, diff_algo);
if (err) {
buf_free(diffb);
diffb = NULL;
goto out;
}
if (asprintf(&dp13, GOT_TMPDIR_STR "/got-d13.XXXXXXXXXX") == -1) {
err = got_error_from_errno("asprintf");
goto out;
}
err = buf_write_stmp(d1, dp13);
if (err)
goto out;
buf_free(d1);
d1 = NULL;
if (asprintf(&dp23, GOT_TMPDIR_STR "/got-d23.XXXXXXXXXX") == -1) {
err = got_error_from_errno("asprintf");
goto out;
}
err = buf_write_stmp(d2, dp23);
if (err)
goto out;
buf_free(d2);
d2 = NULL;
d3s->diffbuf = diffb;
err = diff3_internal(dp13, dp23, path1, path2, path3,
label1, label3, d3s, label1, label2, label3);
if (err) {
buf_free(diffb);
diffb = NULL;
goto out;
}
plen = buf_len(diffb);
patch = buf_release(diffb);
dlen = buf_len(b1);
data = buf_release(b1);
diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines);
out:
buf_free(b2);
buf_free(b3);
buf_free(d1);
buf_free(d2);
if (unlink(path1) == -1 && err == NULL)
err = got_error_from_errno2("unlink", path1);
if (unlink(path2) == -1 && err == NULL)
err = got_error_from_errno2("unlink", path2);
if (unlink(path3) == -1 && err == NULL)
err = got_error_from_errno2("unlink", path3);
if (unlink(dp13) == -1 && err == NULL)
err = got_error_from_errno2("unlink", dp13);
if (unlink(dp23) == -1 && err == NULL)
err = got_error_from_errno2("unlink", dp23);
free(path1);
free(path2);
free(path3);
free(dp13);
free(dp23);
free(data);
free(patch);
for (i = 0; i < nitems(d3s->fp); i++) {
if (d3s->fp[i] && fclose(d3s->fp[i]) == EOF && err == NULL)
err = got_error_from_errno("fclose");
}
if (err == NULL && diffb) {
if (buf_write_fd(diffb, outfd) < 0)
err = got_error_from_errno("buf_write_fd");
*overlapcnt = d3s->overlapcnt;
}
free(d3s);
buf_free(diffb);
return err;
}
static const struct got_error *
diff3_internal(char *dp13, char *dp23, char *path1, char *path2, char *path3,
const char *fmark, const char *rmark, struct diff3_state *d3s,
const char *label1, const char *label2, const char *label3)
{
const struct got_error *err = NULL;
ssize_t m, n;
int i;
i = snprintf(d3s->f1mark, sizeof(d3s->f1mark),
"%s%s%s", GOT_DIFF_CONFLICT_MARKER_BEGIN,
label1 ? " " : "", label1 ? label1 : "");
if (i < 0 || i >= (int)sizeof(d3s->f1mark))
return got_error(GOT_ERR_NO_SPACE);
i = snprintf(d3s->f2mark, sizeof(d3s->f2mark),
"%s%s%s", GOT_DIFF_CONFLICT_MARKER_ORIG,
label2 ? " " : "", label2 ? label2 : "");
if (i < 0 || i >= (int)sizeof(d3s->f2mark))
return got_error(GOT_ERR_NO_SPACE);
i = snprintf(d3s->f3mark, sizeof(d3s->f3mark),
"%s%s%s", GOT_DIFF_CONFLICT_MARKER_END,
label3 ? " " : "", label3 ? label3 : "");
if (i < 0 || i >= (int)sizeof(d3s->f3mark))
return got_error(GOT_ERR_NO_SPACE);
err = increase(d3s);
if (err)
return err;
err = readin(&m, dp13, &d3s->d13, d3s);
if (err)
return err;
err = readin(&n, dp23, &d3s->d23, d3s);
if (err)
return err;
if ((d3s->fp[0] = fopen(path1, "re")) == NULL)
return got_error_from_errno2("fopen", path1);
if ((d3s->fp[1] = fopen(path2, "re")) == NULL)
return got_error_from_errno2("fopen", path2);
if ((d3s->fp[2] = fopen(path3, "re")) == NULL)
return got_error_from_errno2("fopen", path3);
return merge(m, n, d3s);
}
static int
ed_patch_lines(struct rcs_lines *dlines, struct rcs_lines *plines)
{
char op, *ep;
struct rcs_line *sort, *lp, *dlp, *ndlp, *insert_after;
int start, end, i, lineno;
u_char tmp;
dlp = TAILQ_FIRST(&(dlines->l_lines));
lp = TAILQ_FIRST(&(plines->l_lines));
end = 0;
for (lp = TAILQ_NEXT(lp, l_list); lp != NULL;
lp = TAILQ_NEXT(lp, l_list)) {
/* Skip blank lines */
if (lp->l_len < 2)
continue;
/* NUL-terminate line buffer for strtol() safety. */
tmp = lp->l_line[lp->l_len - 1];
lp->l_line[lp->l_len - 1] = '\0';
/* len - 1 is NUL terminator so we use len - 2 for 'op' */
op = lp->l_line[lp->l_len - 2];
start = (int)strtol(lp->l_line, &ep, 10);
/* Restore the last byte of the buffer */
lp->l_line[lp->l_len - 1] = tmp;
if (op == 'a') {
if (start > dlines->l_nblines ||
start < 0 || *ep != 'a')
return -1;
} else if (op == 'c') {
if (start > dlines->l_nblines ||
start < 0 || (*ep != ',' && *ep != 'c'))
return -1;
if (*ep == ',') {
ep++;
end = (int)strtol(ep, &ep, 10);
if (end < 0 || *ep != 'c')
return -1;
} else {
end = start;
}
}
for (;;) {
if (dlp == NULL)
break;
if (dlp->l_lineno == start)
break;
if (dlp->l_lineno > start) {
dlp = TAILQ_PREV(dlp, tqh, l_list);
} else if (dlp->l_lineno < start) {
ndlp = TAILQ_NEXT(dlp, l_list);
if (ndlp->l_lineno > start)
break;
dlp = ndlp;
}
}
if (dlp == NULL)
return -1;
if (op == 'c') {
insert_after = TAILQ_PREV(dlp, tqh, l_list);
for (i = 0; i <= (end - start); i++) {
ndlp = TAILQ_NEXT(dlp, l_list);
TAILQ_REMOVE(&(dlines->l_lines), dlp, l_list);
dlp = ndlp;
}
dlp = insert_after;
}
if (op == 'a' || op == 'c') {
for (;;) {
ndlp = lp;
lp = TAILQ_NEXT(lp, l_list);
if (lp == NULL)
return -1;
if (lp->l_len == 2 &&
lp->l_line[0] == '.' &&
lp->l_line[1] == '\n')
break;
if (lp->l_line[0] == ':') {
lp->l_line++;
lp->l_len--;
}
TAILQ_REMOVE(&(plines->l_lines), lp, l_list);
TAILQ_INSERT_AFTER(&(dlines->l_lines), dlp,
lp, l_list);
dlp = lp;
lp->l_lineno = start;
lp = ndlp;
}
}
/*
* always resort lines as the markers might be put at the
* same line as we first started editing.
*/
lineno = 0;
TAILQ_FOREACH(sort, &(dlines->l_lines), l_list)
sort->l_lineno = lineno++;
dlines->l_nblines = lineno - 1;
}
return (0);
}
/*
* Pick up the line numbers of all changes from one change file.
* (This puts the numbers in a vector, which is not strictly necessary,
* since the vector is processed in one sequential pass.
* The vector could be optimized out of existence)
*/
static const struct got_error *
readin(size_t *n, char *name, struct diff **dd, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
FILE *f;
int a, b, c, d;
char kind, *p;
size_t i = 0;
*n = 0;
f = fopen(name, "re");
if (f == NULL)
return got_error_from_errno2("fopen", name);
err = getchange(&p, f, d3s);
if (err)
goto done;
for (i = 0; p; i++) {
if (i >= d3s->szchanges - 1) {
err = increase(d3s);
if (err)
goto done;
}
a = b = number(&p);
if (*p == ',') {
p++;
b = number(&p);
}
kind = *p++;
c = d = number(&p);
if (*p == ',') {
p++;
d = number(&p);
}
if (kind == 'a')
a++;
if (kind == 'd')
c++;
b++;
d++;
(*dd)[i].old.from = a;
(*dd)[i].old.to = b;
(*dd)[i].new.from = c;
(*dd)[i].new.to = d;
err = getchange(&p, f, d3s);
if (err)
goto done;
}
if (i) {
(*dd)[i].old.from = (*dd)[i - 1].old.to;
(*dd)[i].new.from = (*dd)[i - 1].new.to;
}
done:
if (fclose(f) == EOF && err == NULL)
err = got_error_from_errno("fclose");
if (err == NULL)
*n = i;
return err;
}
static int
number(char **lc)
{
int nn;
nn = 0;
while (isdigit((unsigned char)(**lc)))
nn = nn*10 + *(*lc)++ - '0';
return (nn);
}
static const struct got_error *
getchange(char **line, FILE *b, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
*line = NULL;
do {
if (*line && isdigit((unsigned char)(*line)[0]))
return NULL;
err = get_line(line, b, NULL, d3s);
if (err)
return err;
} while (*line);
return NULL;
}
static const struct got_error *
get_line(char **ret, FILE *b, size_t *n, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
char *cp = NULL;
size_t size;
ssize_t len;
char *new;
*ret = NULL;
if (n != NULL)
*n = 0;
len = getline(&cp, &size, b);
if (len == -1) {
if (ferror(b))
err = got_error_from_errno("getline");
goto done;
}
if (cp[len - 1] != '\n') {
len++;
if (len + 1 > size) {
new = realloc(cp, len + 1);
if (new == NULL) {
err = got_error_from_errno("realloc");
goto done;
}
cp = new;
}
cp[len - 1] = '\n';
cp[len] = '\0';
}
free(d3s->buf);
*ret = d3s->buf = cp;
cp = NULL;
if (n != NULL)
*n = len;
done:
free(cp);
return err;
}
static const struct got_error *
merge(size_t m1, size_t m2, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
struct diff *d1, *d2;
int dpl, j, t1, t2;
d1 = d3s->d13;
d2 = d3s->d23;
j = 0;
for (;;) {
t1 = (d1 < d3s->d13 + m1);
t2 = (d2 < d3s->d23 + m2);
if (!t1 && !t2)
break;
/* first file is different from others */
if (!t2 || (t1 && d1->new.to < d2->new.from)) {
/* stuff peculiar to 1st file */
d1++;
continue;
}
/* second file is different from others */
if (!t1 || (t2 && d2->new.to < d1->new.from)) {
d2++;
continue;
}
/*
* Merge overlapping changes in first file
* this happens after extension (see below).
*/
if (d1 + 1 < d3s->d13 + m1 && d1->new.to >= d1[1].new.from) {
d1[1].old.from = d1->old.from;
d1[1].new.from = d1->new.from;
d1++;
continue;
}
/* merge overlapping changes in second */
if (d2 + 1 < d3s->d23 + m2 && d2->new.to >= d2[1].new.from) {
d2[1].old.from = d2->old.from;
d2[1].new.from = d2->new.from;
d2++;
continue;
}
/* stuff peculiar to third file or different in all */
if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
err = duplicate(&dpl, j, &d1->old, &d2->old, d3s);
if (err)
return err;
/*
* dpl = 0 means all files differ
* dpl = 1 means files 1 and 2 identical
*/
err = edit(d1, dpl, &j, d3s);
if (err)
return err;
d1++;
d2++;
continue;
}
/*
* Overlapping changes from file 1 and 2; extend changes
* appropriately to make them coincide.
*/
if (d1->new.from < d2->new.from) {
d2->old.from -= d2->new.from - d1->new.from;
d2->new.from = d1->new.from;
} else if (d2->new.from < d1->new.from) {
d1->old.from -= d1->new.from - d2->new.from;
d1->new.from = d2->new.from;
}
if (d1->new.to > d2->new.to) {
d2->old.to += d1->new.to - d2->new.to;
d2->new.to = d1->new.to;
} else if (d2->new.to > d1->new.to) {
d1->old.to += d2->new.to - d1->new.to;
d1->new.to = d2->new.to;
}
}
return (edscript(j, d3s));
}
/*
* print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
*/
static const struct got_error *
prange(struct line_range *rold, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
if (rold->to <= rold->from) {
err = diff_output(d3s->diffbuf, "%da\n", rold->from - 1);
if (err)
return err;
} else {
err = diff_output(d3s->diffbuf, "%d", rold->from);
if (err)
return err;
if (rold->to > rold->from + 1) {
err = diff_output(d3s->diffbuf, ",%d", rold->to - 1);
if (err)
return err;
}
err = diff_output(d3s->diffbuf, "c\n");
if (err)
return err;
}
return NULL;
}
/*
* Skip to just before line number from in file "i".
* Return the number of bytes skipped in *nskipped.
*/
static const struct got_error *
skip(size_t *nskipped, int i, int from, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
size_t len, n;
char *line;
*nskipped = 0;
for (n = 0; d3s->cline[i] < from - 1; n += len) {
err = get_line(&line, d3s->fp[i], &len, d3s);
if (err)
return err;
d3s->cline[i]++;
}
*nskipped = n;
return NULL;
}
/*
* Set *dpl to 1 or 0 according as the old range (in file 1) contains exactly
* the same data as the new range (in file 2).
*
* If this change could overlap, remember start/end offsets in file 2 so we
* can write out the original lines of text if a merge conflict occurs.
*/
static const struct got_error *
duplicate(int *dpl, int j, struct line_range *r1, struct line_range *r2,
struct diff3_state *d3s)
{
const struct got_error *err = NULL;
int c,d;
int nchar;
int nline;
size_t nskipped;
off_t off;
*dpl = 0;
if (r1->to - r1->from != r2->to - r2->from)
return NULL;
err = skip(&nskipped, 0, r1->from, d3s);
if (err)
return err;
err = skip(&nskipped, 1, r2->from, d3s);
if (err)
return err;
off = ftello(d3s->fp[1]);
if (off == -1)
return got_error_from_errno("ftello");
d3s->de[j + 1].oldo.from = off; /* original lines start here */
nchar = 0;
for (nline = 0; nline < r1->to - r1->from; nline++) {
do {
c = getc(d3s->fp[0]);
d = getc(d3s->fp[1]);
if (c == EOF && d == EOF)
break;
else if (c == EOF)
return got_ferror(d3s->fp[0], GOT_ERR_EOF);
else if (d == EOF)
return got_ferror(d3s->fp[1], GOT_ERR_EOF);
nchar++;
if (c != d) {
long orig_line_len = nchar;
while (d != '\n') {
d = getc(d3s->fp[1]);
if (d == EOF)
break;
orig_line_len++;
}
if (orig_line_len > nchar &&
fseek(d3s->fp[1], -(orig_line_len - nchar),
SEEK_CUR) == -1)
return got_ferror(d3s->fp[1],
GOT_ERR_IO);
/* original lines end here */
d3s->de[j + 1].oldo.to = off + orig_line_len;
err = repos(nchar, d3s);
if (err)
return err;
return NULL;
}
} while (c != '\n');
}
/* original lines end here */
d3s->de[j + 1].oldo.to = off + nchar;
err = repos(nchar, d3s);
if (err)
return err;
*dpl = 1;
return NULL;
}
static const struct got_error *
repos(int nchar, struct diff3_state *d3s)
{
int i;
for (i = 0; i < 2; i++) {
if (fseek(d3s->fp[i], (long)-nchar, SEEK_CUR) == -1)
return got_ferror(d3s->fp[i], GOT_ERR_IO);
}
return NULL;
}
/*
* collect an editing script for later regurgitation
*/
static const struct got_error *
edit(struct diff *diff, int fdup, int *j, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
size_t nskipped;
if (((fdup + 1) & 3) == 0)
return NULL;
(*j)++;
d3s->overlap[*j] = !fdup;
if (!fdup)
d3s->overlapcnt++;
d3s->de[*j].old.from = diff->old.from;
d3s->de[*j].old.to = diff->old.to;
err = skip(&nskipped, 2, diff->new.from, d3s);
if (err)
return err;
d3s->de[*j].newo.from = d3s->de[*j - 1].newo.to + nskipped;
err = skip(&nskipped, 2, diff->new.to, d3s);
if (err)
return err;
d3s->de[*j].newo.to = d3s->de[*j].newo.from + nskipped;
return NULL;
}
/* regurgitate */
static const struct got_error *
edscript(int n, struct diff3_state *d3s)
{
const struct got_error *err = NULL;
off_t len;
char *line = NULL;
size_t linesize = 0;
ssize_t linelen = 0, k;
for (; n > 0; n--) {
if (!d3s->overlap[n]) {
err = prange(&d3s->de[n].old, d3s);
if (err)
return err;
} else if (d3s->de[n].oldo.from < d3s->de[n].oldo.to) {
/* Output a block of 3-way diff base file content. */
err = diff_output(d3s->diffbuf, "%da\n:%s\n",
d3s->de[n].old.to - 1, d3s->f2mark);
if (err)
return err;
if (fseeko(d3s->fp[1], d3s->de[n].oldo.from, SEEK_SET)
== -1)
return got_error_from_errno("fseeko");
len = (d3s->de[n].oldo.to - d3s->de[n].oldo.from);
for (k = 0; k < (ssize_t)len; k += linelen) {
linelen = getline(&line, &linesize, d3s->fp[1]);
if (linelen == -1) {
if (feof(d3s->fp[1]))
break;
err = got_ferror(d3s->fp[1],
GOT_ERR_IO);
goto done;
}
err = diff_output(d3s->diffbuf, ":%s", line);
if (err)
goto done;
}
err = diff_output(d3s->diffbuf, "%s%s\n",
linelen > 0 && line[linelen] == '\n' ? ":" : "",
GOT_DIFF_CONFLICT_MARKER_SEP);
if (err)
goto done;
} else {
err = diff_output(d3s->diffbuf, "%da\n:%s\n",
d3s->de[n].old.to -1, GOT_DIFF_CONFLICT_MARKER_SEP);
if (err)
goto done;
}
if (fseeko(d3s->fp[2], d3s->de[n].newo.from, SEEK_SET)
== -1) {
err = got_error_from_errno("fseek");
goto done;
}
len = (d3s->de[n].newo.to - d3s->de[n].newo.from);
for (k = 0; k < (ssize_t)len; k += linelen) {
linelen = getline(&line, &linesize, d3s->fp[2]);
if (linelen == -1) {
if (feof(d3s->fp[2]))
break;
err = got_ferror(d3s->fp[2], GOT_ERR_IO);
goto done;
}
err = diff_output(d3s->diffbuf, ":%s", line);
if (err)
goto done;
}
if (!d3s->overlap[n]) {
err = diff_output(d3s->diffbuf, ".\n");
if (err)
goto done;
} else {
err = diff_output(d3s->diffbuf, "%s%s\n.\n",
linelen > 0 && line[linelen] == '\n' ? ":" : "",
d3s->f3mark);
if (err)
goto done;
err = diff_output(d3s->diffbuf, "%da\n:%s\n.\n",
d3s->de[n].old.from - 1, d3s->f1mark);
if (err)
goto done;
}
}
done:
free(line);
return err;
}
static const struct got_error *
increase(struct diff3_state *d3s)
{
size_t newsz, incr;
struct diff *d;
char *s;
/* are the memset(3) calls needed? */
newsz = d3s->szchanges == 0 ? 64 : 2 * d3s->szchanges;
incr = newsz - d3s->szchanges;
d = reallocarray(d3s->d13, newsz, sizeof(*d3s->d13));
if (d == NULL)
return got_error_from_errno("reallocarray");
d3s->d13 = d;
memset(d3s->d13 + d3s->szchanges, 0, incr * sizeof(*d3s->d13));
d = reallocarray(d3s->d23, newsz, sizeof(*d3s->d23));
if (d == NULL)
return got_error_from_errno("reallocarray");
d3s->d23 = d;
memset(d3s->d23 + d3s->szchanges, 0, incr * sizeof(*d3s->d23));
d = reallocarray(d3s->de, newsz, sizeof(*d3s->de));
if (d == NULL)
return got_error_from_errno("reallocarray");
d3s->de = d;
memset(d3s->de + d3s->szchanges, 0, incr * sizeof(*d3s->de));
s = reallocarray(d3s->overlap, newsz, sizeof(*d3s->overlap));
if (s == NULL)
return got_error_from_errno("reallocarray");
d3s->overlap = s;
memset(d3s->overlap + d3s->szchanges, 0, incr * sizeof(*d3s->overlap));
d3s->szchanges = newsz;
return NULL;
}
