#if 0
#ifndef lint
static char sccsid[] = "@(#)diff3.c 8.1 (Berkeley) 6/6/93";
#endif
#endif
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <ctype.h>
#include <err.h>
#include <getopt.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <limits.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
struct range {
int from;
int to;
};
struct diff {
#define DIFF_TYPE2 2
#define DIFF_TYPE3 3
int type;
#if DEBUG
char *line;
#endif
struct range old;
struct range new;
};
#define EFLAG_NONE 0
#define EFLAG_OVERLAP 1
#define EFLAG_NOOVERLAP 2
#define EFLAG_UNMERGED 3
static size_t szchanges;
static struct diff *d13;
static struct diff *d23;
static struct diff *de;
static char *overlap;
static int overlapcnt;
static FILE *fp[3];
static int cline[3];
static int last[4];
static int Aflag, eflag, iflag, mflag, Tflag;
static int oflag;
static int strip_cr;
static char *f1mark, *f2mark, *f3mark;
static const char *oldmark = "<<<<<<<";
static const char *orgmark = "|||||||";
static const char *newmark = ">>>>>>>";
static const char *divider = "=======";
static bool duplicate(struct range *, struct range *);
static int edit(struct diff *, bool, int, int);
static char *getchange(FILE *);
static char *get_line(FILE *, size_t *);
static int readin(int fd, struct diff **);
static int skip(int, int, const char *);
static void change(int, struct range *, bool);
static void keep(int, struct range *);
static void merge(int, int);
static void prange(struct range *, bool);
static void repos(int);
static void edscript(int) __dead;
static void Ascript(int) __dead;
static void mergescript(int) __dead;
static void increase(void);
static void usage(void);
static void printrange(FILE *, struct range *);
static const char diff3_version[] = "FreeBSD diff3 20220517";
enum {
DIFFPROG_OPT,
STRIPCR_OPT,
HELP_OPT,
VERSION_OPT
};
#define DIFF_PATH "/usr/bin/diff"
#define OPTIONS "3aAeEiL:mTxX"
static struct option longopts[] = {
{ "ed", no_argument, NULL, 'e' },
{ "show-overlap", no_argument, NULL, 'E' },
{ "overlap-only", no_argument, NULL, 'x' },
{ "initial-tab", no_argument, NULL, 'T' },
{ "text", no_argument, NULL, 'a' },
{ "strip-trailing-cr", no_argument, NULL, STRIPCR_OPT },
{ "show-all", no_argument, NULL, 'A' },
{ "easy-only", no_argument, NULL, '3' },
{ "merge", no_argument, NULL, 'm' },
{ "label", required_argument, NULL, 'L' },
{ "diff-program", required_argument, NULL, DIFFPROG_OPT },
{ "help", no_argument, NULL, HELP_OPT},
{ "version", no_argument, NULL, VERSION_OPT}
};
static void
usage(void)
{
fprintf(stderr, "usage: diff3 [-3aAeEimTxX] [-L label1] [-L label2] "
"[-L label3] file1 file2 file3\n");
}
static int
readin(int fd, struct diff **dd)
{
int a, b, c, d;
size_t i;
char kind, *p;
FILE *f;
f = fdopen(fd, "r");
if (f == NULL)
err(2, "fdopen");
for (i = 0; (p = getchange(f)); i++) {
#if DEBUG
(*dd)[i].line = strdup(p);
#endif
if (i >= szchanges - 1)
increase();
a = b = (int)strtoimax(p, &p, 10);
if (*p == ',') {
p++;
b = (int)strtoimax(p, &p, 10);
}
kind = *p++;
c = d = (int)strtoimax(p, &p, 10);
if (*p == ',') {
p++;
d = (int)strtoimax(p, &p, 10);
}
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;
}
fclose(f);
return (i);
}
static int
diffexec(const char *diffprog, char **diffargv, int fd[])
{
int pd;
pd = fork();
switch (pd) {
case 0:
close(fd[0]);
if (dup2(fd[1], STDOUT_FILENO) == -1)
err(2, "child could not duplicate descriptor");
close(fd[1]);
execvp(diffprog, diffargv);
err(2, "could not execute diff: %s", diffprog);
break;
case -1:
err(2, "could not fork");
break;
}
close(fd[1]);
return (pd);
}
static char *
getchange(FILE *b)
{
char *line;
while ((line = get_line(b, NULL))) {
if (isdigit((unsigned char)line[0]))
return (line);
}
return (NULL);
}
static char *
get_line(FILE *b, size_t *n)
{
ssize_t len;
static char *buf = NULL;
static size_t bufsize = 0;
if ((len = getline(&buf, &bufsize, b)) < 0)
return (NULL);
if (strip_cr && len >= 2 && strcmp("\r\n", &(buf[len - 2])) == 0) {
buf[len - 2] = '\n';
buf[len - 1] = '\0';
len--;
}
if (n != NULL)
*n = len;
return (buf);
}
static void
merge(int m1, int m2)
{
struct diff *d1, *d2, *d3;
int j, t1, t2;
bool dup = false;
d1 = d13;
d2 = d23;
j = 0;
while (t1 = d1 < d13 + m1, t2 = d2 < d23 + m2, t1 || t2) {
if (!t2 || (t1 && d1->new.to < d2->new.from)) {
if (eflag == EFLAG_NONE) {
printf("====1\n");
change(1, &d1->old, false);
keep(2, &d1->new);
change(3, &d1->new, false);
}
d1++;
continue;
}
if (!t1 || (t2 && d2->new.to < d1->new.from)) {
if (eflag == EFLAG_NONE) {
printf("====2\n");
keep(1, &d2->new);
change(3, &d2->new, false);
change(2, &d2->old, false);
} else if (Aflag || mflag) {
j = edit(d2, dup, j, DIFF_TYPE2);
}
d2++;
continue;
}
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;
}
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;
}
if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {
dup = duplicate(&d1->old, &d2->old);
if (eflag == EFLAG_NONE) {
printf("====%s\n", dup ? "3" : "");
change(1, &d1->old, dup);
change(2, &d2->old, false);
d3 = d1->old.to > d1->old.from ? d1 : d2;
change(3, &d3->new, false);
} else {
j = edit(d1, dup, j, DIFF_TYPE3);
}
dup = false;
d1++;
d2++;
continue;
}
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;
}
}
if (mflag)
mergescript(j);
else if (Aflag)
Ascript(j);
else if (eflag)
edscript(j);
}
static void
change(int i, struct range *rold, bool dup)
{
printf("%d:", i);
last[i] = rold->to;
prange(rold, false);
if (dup)
return;
i--;
skip(i, rold->from, NULL);
skip(i, rold->to, " ");
}
static void
prange(struct range *rold, bool delete)
{
if (rold->to <= rold->from)
printf("%da\n", rold->from - 1);
else {
printf("%d", rold->from);
if (rold->to > rold->from + 1)
printf(",%d", rold->to - 1);
if (delete)
printf("d\n");
else
printf("c\n");
}
}
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, true);
}
static int
skip(int i, int from, const char *pr)
{
size_t j, n;
char *line;
for (n = 0; cline[i] < from - 1; n += j) {
if ((line = get_line(fp[i], &j)) == NULL)
errx(EXIT_FAILURE, "logic error");
if (pr != NULL)
printf("%s%s", Tflag == 1 ? "\t" : pr, line);
cline[i]++;
}
return ((int) n);
}
static bool
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);
skip(0, r1->from, NULL);
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)
break;
if (c == -1 || d == -1)
errx(EXIT_FAILURE, "logic error");
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);
}
static int
edit(struct diff *diff, bool dup, int j, int difftype)
{
if (!(eflag == EFLAG_UNMERGED ||
(!dup && eflag == EFLAG_OVERLAP ) ||
(dup && eflag == EFLAG_NOOVERLAP))) {
return (j);
}
j++;
overlap[j] = !dup;
if (!dup)
overlapcnt++;
de[j].type = difftype;
#if DEBUG
de[j].line = strdup(diff->line);
#endif
de[j].old.from = diff->old.from;
de[j].old.to = diff->old.to;
de[j].new.from = diff->new.from;
de[j].new.to = diff->new.to;
return (j);
}
static void
printrange(FILE *p, struct range *r)
{
char *line = NULL;
size_t len = 0;
int i = 1;
ssize_t rlen = 0;
if (r->from == r->to)
return;
if (r->from > r->to)
errx(EXIT_FAILURE, "invalid print range");
fseek(p, 0L, SEEK_SET);
while ((rlen = getline(&line, &len, p)) > 0) {
if (i >= r->from)
printf("%s", line);
if (++i > r->to - 1)
break;
}
free(line);
}
static void
edscript(int n)
{
bool delete;
struct range *new, *old;
for (; n > 0; n--) {
new = &de[n].new;
old = &de[n].old;
delete = (new->from == new->to);
if (!oflag || !overlap[n]) {
prange(old, delete);
} else {
printf("%da\n", old->to - 1);
printf("%s\n", divider);
}
printrange(fp[2], new);
if (!oflag || !overlap[n]) {
if (!delete)
printf(".\n");
} else {
printf("%s %s\n.\n", newmark, f3mark);
printf("%da\n%s %s\n.\n", old->from - 1,
oldmark, f1mark);
}
}
if (iflag)
printf("w\nq\n");
exit(eflag == EFLAG_NONE ? overlapcnt : 0);
}
static void
Ascript(int n)
{
int startmark;
bool deletenew;
bool deleteold;
struct range *new, *old;
for (; n > 0; n--) {
new = &de[n].new;
old = &de[n].old;
deletenew = (new->from == new->to);
deleteold = (old->from == old->to);
if (de[n].type == DIFF_TYPE2) {
if (!oflag || !overlap[n]) {
prange(old, deletenew);
printrange(fp[2], new);
} else {
startmark = new->to;
if (!deletenew)
startmark--;
printf("%da\n", startmark);
printf("%s %s\n", newmark, f3mark);
printf(".\n");
printf("%da\n", startmark -
(new->to - new->from));
printf("%s %s\n", oldmark, f2mark);
if (!deleteold)
printrange(fp[1], old);
printf("%s\n.\n", divider);
}
} else if (de[n].type == DIFF_TYPE3) {
startmark = old->to - 1;
if (!oflag || !overlap[n]) {
prange(old, deletenew);
printrange(fp[2], new);
} else {
printf("%da\n", startmark);
printf("%s %s\n", orgmark, f2mark);
if (deleteold) {
struct range r;
r.from = old->from-1;
r.to = new->to;
printrange(fp[1], &r);
} else
printrange(fp[1], old);
printf("%s\n", divider);
printrange(fp[2], new);
}
if (!oflag || !overlap[n]) {
if (!deletenew)
printf(".\n");
} else {
printf("%s %s\n.\n", newmark, f3mark);
printf("%da\n%s %s\n.\n",
startmark - (old->to - old->from),
oldmark, f1mark);
}
}
}
if (iflag)
printf("w\nq\n");
exit(overlapcnt > 0);
}
static void
mergescript(int i)
{
struct range r, *new, *old;
int n;
r.from = 1;
r.to = 1;
for (n = 1; n < i+1; n++) {
new = &de[n].new;
old = &de[n].old;
r.to = old->from;
printrange(fp[0], &r);
if (de[n].type == DIFF_TYPE2) {
printf("%s %s\n", oldmark, f2mark);
printrange(fp[1], old);
printf("%s\n", divider);
printrange(fp[2], new);
printf("%s %s\n", newmark, f3mark);
} else if (de[n].type == DIFF_TYPE3) {
if (!oflag || !overlap[n]) {
printrange(fp[2], new);
} else {
printf("%s %s\n", oldmark, f1mark);
printrange(fp[0], old);
printf("%s %s\n", orgmark, f2mark);
if (old->from == old->to) {
struct range or;
or.from = old->from - 1;
or.to = new->to;
printrange(fp[1], &or);
} else
printrange(fp[1], old);
printf("%s\n", divider);
printrange(fp[2], new);
printf("%s %s\n", newmark, f3mark);
}
}
if (old->from == old->to)
r.from = new->to;
else
r.from = old->to;
}
new = &de[n-1].new;
old = &de[n-1].old;
if ((old->from == new->from) &&
(old->to == new->to))
r.from--;
else if (new->from == new->to)
r.from = old->from;
if (de[n-1].type == DIFF_TYPE3)
r.from++;
r.to = INT_MAX;
printrange(fp[0], &r);
exit(overlapcnt > 0);
}
static void
increase(void)
{
struct diff *p;
char *q;
size_t newsz, incr;
newsz = szchanges == 0 ? 64 : 2 * szchanges;
incr = newsz - szchanges;
p = reallocarray(d13, newsz, sizeof(struct diff));
if (p == NULL)
err(1, NULL);
memset(p + szchanges, 0, incr * sizeof(struct diff));
d13 = p;
p = reallocarray(d23, newsz, sizeof(struct diff));
if (p == NULL)
err(1, NULL);
memset(p + szchanges, 0, incr * sizeof(struct diff));
d23 = p;
p = reallocarray(de, newsz, sizeof(struct diff));
if (p == NULL)
err(1, NULL);
memset(p + szchanges, 0, incr * sizeof(struct diff));
de = p;
q = reallocarray(overlap, newsz, sizeof(char));
if (q == NULL)
err(1, NULL);
memset(q + szchanges, 0, incr * sizeof(char));
overlap = q;
szchanges = newsz;
}
static void
wait_and_check(pid_t pd)
{
int status;
if (waitpid(pd, &status, 0) == -1)
err(2, "waitpid");
if (WIFEXITED(status) && WEXITSTATUS(status) >= 2)
errx(2, "diff exited abnormally");
if (WIFSIGNALED(status))
errx(2, "diff killed by signal %d", WTERMSIG(status));
}
int
main(int argc, char **argv)
{
int ch, nblabels, m, n;
char *labels[] = { NULL, NULL, NULL };
const char *diffprog = DIFF_PATH;
char *file1, *file2, *file3;
char *diffargv[7];
int diffargc = 0;
int fd13[2], fd23[2];
int pd13, pd23;
nblabels = 0;
eflag = EFLAG_NONE;
oflag = 0;
diffargv[diffargc++] = __UNCONST(diffprog);
while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
switch (ch) {
case '3':
eflag = EFLAG_NOOVERLAP;
break;
case 'a':
diffargv[diffargc++] = __UNCONST("-a");
break;
case 'A':
Aflag = 1;
break;
case 'e':
eflag = EFLAG_UNMERGED;
break;
case 'E':
eflag = EFLAG_UNMERGED;
oflag = 1;
break;
case 'i':
iflag = 1;
break;
case 'L':
oflag = 1;
if (nblabels >= 3)
errx(2, "too many file label options");
labels[nblabels++] = optarg;
break;
case 'm':
Aflag = 1;
oflag = 1;
mflag = 1;
break;
case 'T':
Tflag = 1;
break;
case 'x':
eflag = EFLAG_OVERLAP;
break;
case 'X':
oflag = 1;
eflag = EFLAG_OVERLAP;
break;
case DIFFPROG_OPT:
diffprog = optarg;
break;
case STRIPCR_OPT:
strip_cr = 1;
diffargv[diffargc++] = __UNCONST("--strip-trailing-cr");
break;
case HELP_OPT:
usage();
exit(0);
case VERSION_OPT:
printf("%s\n", diff3_version);
exit(0);
}
}
argc -= optind;
argv += optind;
if (Aflag) {
eflag = EFLAG_UNMERGED;
oflag = 1;
}
if (argc != 3) {
usage();
exit(2);
}
file1 = argv[0];
file2 = argv[1];
file3 = argv[2];
if (oflag) {
asprintf(&f1mark, "%s",
labels[0] != NULL ? labels[0] : file1);
if (f1mark == NULL)
err(2, "asprintf");
asprintf(&f2mark, "%s",
labels[1] != NULL ? labels[1] : file2);
if (f2mark == NULL)
err(2, "asprintf");
asprintf(&f3mark, "%s",
labels[2] != NULL ? labels[2] : file3);
if (f3mark == NULL)
err(2, "asprintf");
}
fp[0] = fopen(file1, "r");
if (fp[0] == NULL)
err(2, "Can't open %s", file1);
fp[1] = fopen(file2, "r");
if (fp[1] == NULL)
err(2, "Can't open %s", file2);
fp[2] = fopen(file3, "r");
if (fp[2] == NULL)
err(2, "Can't open %s", file3);
if (pipe(fd13))
err(2, "pipe");
if (pipe(fd23))
err(2, "pipe");
diffargv[diffargc] = file1;
diffargv[diffargc + 1] = file3;
diffargv[diffargc + 2] = NULL;
pd13 = diffexec(diffprog, diffargv, fd13);
diffargv[diffargc] = file2;
pd23 = diffexec(diffprog, diffargv, fd23);
increase();
m = readin(fd13[0], &d13);
n = readin(fd23[0], &d23);
wait_and_check(pd13);
wait_and_check(pd23);
merge(m, n);
return (EXIT_SUCCESS);
}
