OpenBSD-4.6/usr.bin/rcs/diff3.c
/* $OpenBSD: diff3.c,v 1.27 2009/02/25 23:16:20 ray 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
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char rcsid[] =
"$OpenBSD: diff3.c,v 1.27 2009/02/25 23:16:20 ray Exp $";
#endif /* not lint */
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "diff.h"
#include "rcsprog.h"
/* 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 range {
int from;
int to;
};
struct diff {
struct range old;
struct range new;
};
static size_t szchanges;
static struct diff *d13;
static 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 or byte positions depending on when you
* look (!?). Array overlap indicates which sections in "de" correspond to
* lines that are different in all three files.
*/
static struct diff *de;
static char *overlap;
static int overlapcnt = 0;
static FILE *fp[3];
static 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];
*/
static int last[4];
static int eflag = 3; /* default -E for compatibility with former RCS */
static int oflag = 1; /* default -E for compatibility with former RCS */
static int debug = 0;
static char f1mark[256], f3mark[256]; /* markers for -E and -X */
static int duplicate(struct range *, struct range *);
static int edit(struct diff *, int, int);
static char *getchange(FILE *);
static char *getline(FILE *, size_t *);
static int number(char **);
static ssize_t readin(char *, struct diff **);
static int skip(int, int, char *);
static int edscript(int);
static int merge(size_t, size_t);
static void change(int, struct range *, int);
static void keep(int, struct range *);
static void prange(struct range *);
static void repos(int);
static void separate(const char *);
static void increase(void);
static int diff3_internal(int, char **, const char *, const char *);
int diff3_conflicts = 0;
/*
* For merge(1).
*/
BUF *
merge_diff3(char **av, int flags)
{
int argc;
char *argv[5], *dp13, *dp23, *path1, *path2, *path3;
BUF *b1, *b2, *b3, *d1, *d2, *diffb;
u_char *data, *patch;
size_t dlen, plen;
b1 = b2 = b3 = d1 = d2 = diffb = NULL;
dp13 = dp23 = path1 = path2 = path3 = NULL;
data = patch = NULL;
if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
oflag = 0;
if ((b1 = rcs_buf_load(av[0], BUF_AUTOEXT)) == NULL)
goto out;
if ((b2 = rcs_buf_load(av[1], BUF_AUTOEXT)) == NULL)
goto out;
if ((b3 = rcs_buf_load(av[2], BUF_AUTOEXT)) == NULL)
goto out;
d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
(void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
(void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
(void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(b1, path1);
rcs_buf_write_stmp(b2, path2);
rcs_buf_write_stmp(b3, path3);
rcs_buf_free(b2);
b2 = NULL;
if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) ||
(diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) {
rcs_buf_free(diffb);
diffb = NULL;
goto out;
}
(void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(d1, dp13);
rcs_buf_free(d1);
d1 = NULL;
(void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(d2, dp23);
rcs_buf_free(d2);
d2 = NULL;
argc = 0;
diffbuf = diffb;
argv[argc++] = dp13;
argv[argc++] = dp23;
argv[argc++] = path1;
argv[argc++] = path2;
argv[argc++] = path3;
diff3_conflicts = diff3_internal(argc, argv, av[0], av[2]);
if (diff3_conflicts < 0) {
rcs_buf_free(diffb);
diffb = NULL;
goto out;
}
plen = rcs_buf_len(diffb);
patch = rcs_buf_release(diffb);
dlen = rcs_buf_len(b1);
data = rcs_buf_release(b1);
if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL)
goto out;
if (!(flags & QUIET) && diff3_conflicts != 0)
warnx("warning: overlaps or other problems during merge");
out:
if (b2 != NULL)
rcs_buf_free(b2);
if (b3 != NULL)
rcs_buf_free(b3);
if (d1 != NULL)
rcs_buf_free(d1);
if (d2 != NULL)
rcs_buf_free(d2);
(void)unlink(path1);
(void)unlink(path2);
(void)unlink(path3);
(void)unlink(dp13);
(void)unlink(dp23);
if (path1 != NULL)
xfree(path1);
if (path2 != NULL)
xfree(path2);
if (path3 != NULL)
xfree(path3);
if (dp13 != NULL)
xfree(dp13);
if (dp23 != NULL)
xfree(dp23);
if (data != NULL)
xfree(data);
if (patch != NULL)
xfree(patch);
return (diffb);
}
BUF *
rcs_diff3(RCSFILE *rf, char *workfile, RCSNUM *rev1, RCSNUM *rev2, int flags)
{
int argc;
char *argv[5], r1[RCS_REV_BUFSZ], r2[RCS_REV_BUFSZ];
char *dp13, *dp23, *path1, *path2, *path3;
BUF *b1, *b2, *b3, *d1, *d2, *diffb;
size_t dlen, plen;
u_char *data, *patch;
b1 = b2 = b3 = d1 = d2 = diffb = NULL;
dp13 = dp23 = path1 = path2 = path3 = NULL;
data = patch = NULL;
if ((flags & MERGE_EFLAG) && !(flags & MERGE_OFLAG))
oflag = 0;
rcsnum_tostr(rev1, r1, sizeof(r1));
rcsnum_tostr(rev2, r2, sizeof(r2));
if ((b1 = rcs_buf_load(workfile, BUF_AUTOEXT)) == NULL)
goto out;
if (!(flags & QUIET))
(void)fprintf(stderr, "retrieving revision %s\n", r1);
if ((b2 = rcs_getrev(rf, rev1)) == NULL)
goto out;
if (!(flags & QUIET))
(void)fprintf(stderr, "retrieving revision %s\n", r2);
if ((b3 = rcs_getrev(rf, rev2)) == NULL)
goto out;
d1 = rcs_buf_alloc(128, BUF_AUTOEXT);
d2 = rcs_buf_alloc(128, BUF_AUTOEXT);
diffb = rcs_buf_alloc(128, BUF_AUTOEXT);
(void)xasprintf(&path1, "%s/diff1.XXXXXXXXXX", rcs_tmpdir);
(void)xasprintf(&path2, "%s/diff2.XXXXXXXXXX", rcs_tmpdir);
(void)xasprintf(&path3, "%s/diff3.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(b1, path1);
rcs_buf_write_stmp(b2, path2);
rcs_buf_write_stmp(b3, path3);
rcs_buf_free(b2);
b2 = NULL;
if ((diffreg(path1, path3, d1, D_FORCEASCII) == D_ERROR) ||
(diffreg(path2, path3, d2, D_FORCEASCII) == D_ERROR)) {
rcs_buf_free(diffb);
diffb = NULL;
goto out;
}
(void)xasprintf(&dp13, "%s/d13.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(d1, dp13);
rcs_buf_free(d1);
d1 = NULL;
(void)xasprintf(&dp23, "%s/d23.XXXXXXXXXX", rcs_tmpdir);
rcs_buf_write_stmp(d2, dp23);
rcs_buf_free(d2);
d2 = NULL;
argc = 0;
diffbuf = diffb;
argv[argc++] = dp13;
argv[argc++] = dp23;
argv[argc++] = path1;
argv[argc++] = path2;
argv[argc++] = path3;
diff3_conflicts = diff3_internal(argc, argv, workfile, r2);
if (diff3_conflicts < 0) {
rcs_buf_free(diffb);
diffb = NULL;
goto out;
}
plen = rcs_buf_len(diffb);
patch = rcs_buf_release(diffb);
dlen = rcs_buf_len(b1);
data = rcs_buf_release(b1);
if ((diffb = rcs_patchfile(data, dlen, patch, plen, ed_patch_lines)) == NULL)
goto out;
if (!(flags & QUIET) && diff3_conflicts != 0)
warnx("warning: overlaps or other problems during merge");
out:
if (b2 != NULL)
rcs_buf_free(b2);
if (b3 != NULL)
rcs_buf_free(b3);
if (d1 != NULL)
rcs_buf_free(d1);
if (d2 != NULL)
rcs_buf_free(d2);
(void)unlink(path1);
(void)unlink(path2);
(void)unlink(path3);
(void)unlink(dp13);
(void)unlink(dp23);
if (path1 != NULL)
xfree(path1);
if (path2 != NULL)
xfree(path2);
if (path3 != NULL)
xfree(path3);
if (dp13 != NULL)
xfree(dp13);
if (dp23 != NULL)
xfree(dp23);
if (data != NULL)
xfree(data);
if (patch != NULL)
xfree(patch);
return (diffb);
}
static int
diff3_internal(int argc, char **argv, const char *fmark, const char *rmark)
{
ssize_t m, n;
int i;
if (argc < 5)
return (-1);
if (oflag) {
i = snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s", fmark);
if (i < 0 || i >= (int)sizeof(f1mark))
errx(1, "diff3_internal: string truncated");
i = snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s", rmark);
if (i < 0 || i >= (int)sizeof(f3mark))
errx(1, "diff3_internal: string truncated");
}
increase();
if ((m = readin(argv[0], &d13)) < 0) {
warn("%s", argv[0]);
return (-1);
}
if ((n = readin(argv[1], &d23)) < 0) {
warn("%s", argv[1]);
return (-1);
}
for (i = 0; i <= 2; i++)
if ((fp[i] = fopen(argv[i + 2], "r")) == NULL) {
warn("%s", argv[i + 2]);
return (-1);
}
return (merge(m, n));
}
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')
errx(1, "ed_patch_lines");
} else if (op == 'c') {
if (start > dlines->l_nblines ||
start < 0 || (*ep != ',' && *ep != 'c'))
errx(1, "ed_patch_lines");
if (*ep == ',') {
ep++;
end = (int)strtol(ep, &ep, 10);
if (end < 0 || *ep != 'c')
errx(1, "ed_patch_lines");
} else {
end = start;
}
}
for (;;) {
if (dlp == NULL)
break;
if (dlp->l_lineno == start)
break;
if (dlp->l_lineno > start) {
dlp = TAILQ_PREV(dlp, rcs_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)
errx(1, "ed_patch_lines");
if (op == 'c') {
insert_after = TAILQ_PREV(dlp, rcs_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)
errx(1, "ed_patch_lines");
if (!memcmp(lp->l_line, ".", 1))
break;
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 ssize_t
readin(char *name, struct diff **dd)
{
int a, b, c, d;
char kind, *p;
size_t i;
fp[0] = fopen(name, "r");
if (fp[0] == NULL)
return (-1);
for (i = 0; (p = getchange(fp[0])); i++) {
if (i >= szchanges - 1)
increase();
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;
}
if (i) {
(*dd)[i].old.from = (*dd)[i-1].old.to;
(*dd)[i].new.from = (*dd)[i-1].new.to;
}
(void)fclose(fp[0]);
return (i);
}
static int
number(char **lc)
{
int nn;
nn = 0;
while (isdigit((unsigned char)(**lc)))
nn = nn*10 + *(*lc)++ - '0';
return (nn);
}
static char *
getchange(FILE *b)
{
char *line;
while ((line = getline(b, NULL))) {
if (isdigit((unsigned char)line[0]))
return (line);
}
return (NULL);
}
static char *
getline(FILE *b, size_t *n)
{
char *cp;
size_t len;
static char *buf;
static size_t bufsize;
if ((cp = fgetln(b, &len)) == NULL)
return (NULL);
if (cp[len - 1] != '\n')
len++;
if (len + 1 > bufsize) {
do {
bufsize += 1024;
} while (len + 1 > bufsize);
buf = xrealloc(buf, 1, bufsize);
}
memcpy(buf, cp, len - 1);
buf[len - 1] = '\n';
buf[len] = '\0';
if (n != NULL)
*n = len;
return (buf);
}
static int
merge(size_t m1, size_t m2)
{
struct diff *d1, *d2, *d3;
int dpl, j, t1, t2;
d1 = d13;
d2 = d23;
j = 0;
while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
if (debug) {
printf("%d,%d=%d,%d %d,%d=%d,%d\n",
d1->old.from, d1->old.to,
d1->new.from, d1->new.to,
d2->old.from, d2->old.to,
d2->new.from, d2->new.to);
}
/* first file is different from others */
if (!t2 || (t1 && d1->new.to < d2->new.from)) {
/* stuff peculiar to 1st file */
if (eflag==0) {
separate("1");
change(1, &d1->old, 0);
keep(2, &d1->new);
change(3, &d1->new, 0);
}
d1++;
continue;
}
/* second file is different from others */
if (!t1 || (t2 && d2->new.to < d1->new.from)) {
if (eflag==0) {
separate("2");
keep(1, &d2->new);
change(2, &d2->old, 0);
change(3, &d2->new, 0);
}
d2++;
continue;
}
/*
* Merge overlapping changes in first file
* this happens after extension (see below).
*/
if (d1 + 1 < 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 < 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) {
dpl = duplicate(&d1->old,&d2->old);
if (dpl == -1)
return (-1);
/*
* dpl = 0 means all files differ
* dpl = 1 means files 1 and 2 identical
*/
if (eflag==0) {
separate(dpl ? "3" : "");
change(1, &d1->old, dpl);
change(2, &d2->old, 0);
d3 = d1->old.to > d1->old.from ? d1 : d2;
change(3, &d3->new, 0);
} else
j = edit(d1, dpl, j);
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));
}
static void
separate(const char *s)
{
diff_output("====%s\n", s);
}
/*
* The range of lines rold.from thru rold.to in file i is to be changed.
* It is to be printed only if it does not duplicate something to be
* printed later.
*/
static void
change(int i, struct range *rold, int fdup)
{
diff_output("%d:", i);
last[i] = rold->to;
prange(rold);
if (fdup || debug)
return;
i--;
(void)skip(i, rold->from, NULL);
(void)skip(i, rold->to, " ");
}
/*
* print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1
*/
static void
prange(struct range *rold)
{
if (rold->to <= rold->from)
diff_output("%da\n", rold->from - 1);
else {
diff_output("%d", rold->from);
if (rold->to > rold->from+1)
diff_output(",%d", rold->to - 1);
diff_output("c\n");
}
}
/*
* No difference was reported by diff between file 1 (or 2) and file 3,
* and an artificial dummy difference (trange) must be ginned up to
* correspond to the change reported in the other file.
*/
static void
keep(int i, struct range *rnew)
{
int delta;
struct range trange;
delta = last[3] - last[i];
trange.from = rnew->from - delta;
trange.to = rnew->to - delta;
change(i, &trange, 1);
}
/*
* skip to just before line number from in file "i". If "pr" is non-NULL,
* print all skipped stuff with string pr as a prefix.
*/
static int
skip(int i, int from, char *pr)
{
size_t j, n;
char *line;
for (n = 0; cline[i] < from - 1; n += j) {
if ((line = getline(fp[i], &j)) == NULL)
return (-1);
if (pr != NULL)
diff_output("%s%s", pr, line);
cline[i]++;
}
return ((int) n);
}
/*
* Return 1 or 0 according as the old range (in file 1) contains exactly
* the same data as the new range (in file 2).
*/
static int
duplicate(struct range *r1, struct range *r2)
{
int c,d;
int nchar;
int nline;
if (r1->to-r1->from != r2->to-r2->from)
return (0);
(void)skip(0, r1->from, NULL);
(void)skip(1, r2->from, NULL);
nchar = 0;
for (nline=0; nline < r1->to - r1->from; nline++) {
do {
c = getc(fp[0]);
d = getc(fp[1]);
if (c == -1 || d== -1)
return (-1);
nchar++;
if (c != d) {
repos(nchar);
return (0);
}
} while (c != '\n');
}
repos(nchar);
return (1);
}
static void
repos(int nchar)
{
int i;
for (i = 0; i < 2; i++)
(void)fseek(fp[i], (long)-nchar, SEEK_CUR);
}
/*
* collect an editing script for later regurgitation
*/
static int
edit(struct diff *diff, int fdup, int j)
{
if (((fdup + 1) & eflag) == 0)
return (j);
j++;
overlap[j] = !fdup;
if (!fdup)
overlapcnt++;
de[j].old.from = diff->old.from;
de[j].old.to = diff->old.to;
de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);
de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);
return (j);
}
/* regurgitate */
static int
edscript(int n)
{
int j, k;
char block[BUFSIZ+1];
for (n = n; n > 0; n--) {
if (!oflag || !overlap[n])
prange(&de[n].old);
else
diff_output("%da\n=======\n", de[n].old.to -1);
(void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);
for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
j = k > BUFSIZ ? BUFSIZ : k;
if (fread(block, 1, (size_t)j,
fp[2]) != (size_t)j)
return (-1);
block[j] = '\0';
diff_output("%s", block);
}
if (!oflag || !overlap[n])
diff_output(".\n");
else {
diff_output("%s\n.\n", f3mark);
diff_output("%da\n%s\n.\n", de[n].old.from - 1, f1mark);
}
}
return (overlapcnt);
}
static void
increase(void)
{
size_t newsz, incr;
/* are the memset(3) calls needed? */
newsz = szchanges == 0 ? 64 : 2 * szchanges;
incr = newsz - szchanges;
d13 = xrealloc(d13, newsz, sizeof(*d13));
memset(d13 + szchanges, 0, incr * sizeof(*d13));
d23 = xrealloc(d23, newsz, sizeof(*d23));
memset(d23 + szchanges, 0, incr * sizeof(*d23));
de = xrealloc(de, newsz, sizeof(*de));
memset(de + szchanges, 0, incr * sizeof(*de));
overlap = xrealloc(overlap, newsz, sizeof(*overlap));
memset(overlap + szchanges, 0, incr * sizeof(*overlap));
szchanges = newsz;
}