OpenBSD-4.6/usr.bin/rcs/diff.c
/* $OpenBSD: diff.c,v 1.26 2009/06/07 08:39:13 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.
* Copyright (c) 2004 Jean-Francois Brousseau. 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.
*
* @(#)diffreg.c 8.1 (Berkeley) 6/6/93
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <ctype.h>
#include <err.h>
#include <limits.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "buf.h"
#include "diff.h"
#include "xmalloc.h"
/*
* diff - compare two files.
*/
/*
* Uses an algorithm due to Harold Stone, which finds
* a pair of longest identical subsequences in the two
* files.
*
* The major goal is to generate the match vector J.
* J[i] is the index of the line in file1 corresponding
* to line i file0. J[i] = 0 if there is no
* such line in file1.
*
* Lines are hashed so as to work in core. All potential
* matches are located by sorting the lines of each file
* on the hash (called ``value''). In particular, this
* collects the equivalence classes in file1 together.
* Subroutine equiv replaces the value of each line in
* file0 by the index of the first element of its
* matching equivalence in (the reordered) file1.
* To save space equiv squeezes file1 into a single
* array member in which the equivalence classes
* are simply concatenated, except that their first
* members are flagged by changing sign.
*
* Next the indices that point into member are unsorted into
* array class according to the original order of file0.
*
* The cleverness lies in routine stone. This marches
* through the lines of file0, developing a vector klist
* of "k-candidates". At step i a k-candidate is a matched
* pair of lines x,y (x in file0 y in file1) such that
* there is a common subsequence of length k
* between the first i lines of file0 and the first y
* lines of file1, but there is no such subsequence for
* any smaller y. x is the earliest possible mate to y
* that occurs in such a subsequence.
*
* Whenever any of the members of the equivalence class of
* lines in file1 matable to a line in file0 has serial number
* less than the y of some k-candidate, that k-candidate
* with the smallest such y is replaced. The new
* k-candidate is chained (via pred) to the current
* k-1 candidate so that the actual subsequence can
* be recovered. When a member has serial number greater
* that the y of all k-candidates, the klist is extended.
* At the end, the longest subsequence is pulled out
* and placed in the array J by unravel
*
* With J in hand, the matches there recorded are
* check'ed against reality to assure that no spurious
* matches have crept in due to hashing. If they have,
* they are broken, and "jackpot" is recorded--a harmless
* matter except that a true match for a spuriously
* mated line may now be unnecessarily reported as a change.
*
* Much of the complexity of the program comes simply
* from trying to minimize core utilization and
* maximize the range of doable problems by dynamically
* allocating what is needed and reusing what is not.
* The core requirements for problems larger than somewhat
* are (in words) 2*length(file0) + length(file1) +
* 3*(number of k-candidates installed), typically about
* 6n words for files of length n.
*/
struct cand {
int x;
int y;
int pred;
};
struct line {
int serial;
int value;
} *file[2];
/*
* The following struct is used to record change information when
* doing a "context" or "unified" diff. (see routine "change" to
* understand the highly mnemonic field names)
*/
struct context_vec {
int a; /* start line in old file */
int b; /* end line in old file */
int c; /* start line in new file */
int d; /* end line in new file */
};
static void output(FILE *, FILE *, int);
static void check(FILE *, FILE *, int);
static void range(int, int, char *);
static void uni_range(int, int);
static void dump_context_vec(FILE *, FILE *, int);
static void dump_unified_vec(FILE *, FILE *, int);
static void prepare(int, FILE *, off_t, int);
static void prune(void);
static void equiv(struct line *, int, struct line *, int, int *);
static void unravel(int);
static void unsort(struct line *, int, int *);
static void change(FILE *, FILE *, int, int, int, int, int);
static void sort(struct line *, int);
static int ignoreline(char *);
static int asciifile(FILE *);
static void fetch(long *, int, int, FILE *, int, int, int);
static int newcand(int, int, int);
static int search(int *, int, int);
static int skipline(FILE *);
static int isqrt(int);
static int stone(int *, int, int *, int *, int);
static int readhash(FILE *, int);
static int files_differ(FILE *, FILE *);
static char *match_function(const long *, int, FILE *);
static char *preadline(int, size_t, off_t);
int diff_context = 3;
int diff_format = D_NORMAL;
char *diff_file = NULL;
RCSNUM *diff_rev1 = NULL;
RCSNUM *diff_rev2 = NULL;
char diffargs[512]; /* XXX */
static struct stat stb1, stb2;
static char *ifdefname;
regex_t *diff_ignore_re;
static int *J; /* will be overlaid on class */
static int *class; /* will be overlaid on file[0] */
static int *klist; /* will be overlaid on file[0] after class */
static int *member; /* will be overlaid on file[1] */
static int clen;
static int inifdef; /* whether or not we are in a #ifdef block */
static int len[2];
static int pref, suff; /* length of prefix and suffix */
static int slen[2];
static int anychange;
static long *ixnew; /* will be overlaid on file[1] */
static long *ixold; /* will be overlaid on klist */
static struct cand *clist; /* merely a free storage pot for candidates */
static int clistlen; /* the length of clist */
static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
static u_char *chrtran; /* translation table for case-folding */
static struct context_vec *context_vec_start;
static struct context_vec *context_vec_end;
static struct context_vec *context_vec_ptr;
#define FUNCTION_CONTEXT_SIZE 55
static char lastbuf[FUNCTION_CONTEXT_SIZE];
static int lastline;
static int lastmatchline;
BUF *diffbuf = NULL;
/*
* chrtran points to one of 2 translation tables: cup2low if folding upper to
* lower case clow2low if not folding case
*/
u_char clow2low[256] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36,
0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41,
0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, 0x60, 0x61, 0x62,
0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d,
0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83,
0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e,
0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4,
0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6,
0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1,
0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc,
0xfd, 0xfe, 0xff
};
u_char cup2low[256] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36,
0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, 0x60, 0x61,
0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c,
0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x60, 0x61, 0x62,
0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d,
0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83,
0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e,
0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4,
0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0,
0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb,
0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6,
0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1,
0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc,
0xfd, 0xfe, 0xff
};
int
diffreg(const char *file1, const char *file2, BUF *out, int flags)
{
FILE *f1, *f2;
int i, rval;
f1 = f2 = NULL;
rval = D_SAME;
anychange = 0;
lastline = 0;
lastmatchline = 0;
context_vec_ptr = context_vec_start - 1;
if (flags & D_IGNORECASE)
chrtran = cup2low;
else
chrtran = clow2low;
if (out != NULL)
diffbuf = out;
f1 = fopen(file1, "r");
if (f1 == NULL) {
warn("%s", file1);
goto closem;
}
f2 = fopen(file2, "r");
if (f2 == NULL) {
warn("%s", file2);
goto closem;
}
if (fstat(fileno(f1), &stb1) < 0) {
warn("%s", file1);
goto closem;
}
if (fstat(fileno(f2), &stb2) < 0) {
warn("%s", file2);
goto closem;
}
switch (files_differ(f1, f2)) {
case 1:
break;
case -1:
rval = D_ERROR;
/* FALLTHROUGH */
case 0:
goto closem;
default:
errx(D_ERROR, "files_differ: invalid case");
}
if ((flags & D_FORCEASCII) == 0 &&
(!asciifile(f1) || !asciifile(f2))) {
rval = D_ERROR;
goto closem;
}
prepare(0, f1, stb1.st_size, flags);
prepare(1, f2, stb2.st_size, flags);
prune();
sort(sfile[0], slen[0]);
sort(sfile[1], slen[1]);
member = (int *)file[1];
equiv(sfile[0], slen[0], sfile[1], slen[1], member);
member = xrealloc(member, slen[1] + 2, sizeof(*member));
class = (int *)file[0];
unsort(sfile[0], slen[0], class);
class = xrealloc(class, slen[0] + 2, sizeof(*class));
klist = xcalloc(slen[0] + 2, sizeof(*klist));
clen = 0;
clistlen = 100;
clist = xcalloc(clistlen, sizeof(*clist));
i = stone(class, slen[0], member, klist, flags);
xfree(member);
xfree(class);
J = xrealloc(J, len[0] + 2, sizeof(*J));
unravel(klist[i]);
xfree(clist);
xfree(klist);
ixold = xrealloc(ixold, len[0] + 2, sizeof(*ixold));
ixnew = xrealloc(ixnew, len[1] + 2, sizeof(*ixnew));
check(f1, f2, flags);
output(f1, f2, flags);
closem:
if (anychange) {
if (rval == D_SAME)
rval = D_DIFFER;
}
if (f1 != NULL)
fclose(f1);
if (f2 != NULL)
fclose(f2);
return (rval);
}
/*
* Check to see if the given files differ.
* Returns 0 if they are the same, 1 if different, and -1 on error.
* XXX - could use code from cmp(1) [faster]
*/
static int
files_differ(FILE *f1, FILE *f2)
{
char buf1[BUFSIZ], buf2[BUFSIZ];
size_t i, j;
if (stb1.st_size != stb2.st_size)
return (1);
for (;;) {
i = fread(buf1, 1, sizeof(buf1), f1);
j = fread(buf2, 1, sizeof(buf2), f2);
if (i != j)
return (1);
if (i == 0 && j == 0) {
if (ferror(f1) || ferror(f2))
return (-1);
return (0);
}
if (memcmp(buf1, buf2, i) != 0)
return (1);
}
}
static void
prepare(int i, FILE *fd, off_t filesize, int flags)
{
struct line *p;
int j, h;
size_t sz;
rewind(fd);
sz = (filesize <= SIZE_MAX ? filesize : SIZE_MAX) / 25;
if (sz < 100)
sz = 100;
p = xcalloc(sz + 3, sizeof(*p));
for (j = 0; (h = readhash(fd, flags));) {
if (j == sz) {
sz = sz * 3 / 2;
p = xrealloc(p, sz + 3, sizeof(*p));
}
p[++j].value = h;
}
len[i] = j;
file[i] = p;
}
static void
prune(void)
{
int i, j;
for (pref = 0; pref < len[0] && pref < len[1] &&
file[0][pref + 1].value == file[1][pref + 1].value;
pref++)
;
for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
file[0][len[0] - suff].value == file[1][len[1] - suff].value;
suff++)
;
for (j = 0; j < 2; j++) {
sfile[j] = file[j] + pref;
slen[j] = len[j] - pref - suff;
for (i = 0; i <= slen[j]; i++)
sfile[j][i].serial = i;
}
}
static void
equiv(struct line *a, int n, struct line *b, int m, int *c)
{
int i, j;
i = j = 1;
while (i <= n && j <= m) {
if (a[i].value < b[j].value)
a[i++].value = 0;
else if (a[i].value == b[j].value)
a[i++].value = j;
else
j++;
}
while (i <= n)
a[i++].value = 0;
b[m + 1].value = 0;
j = 0;
while (++j <= m) {
c[j] = -b[j].serial;
while (b[j + 1].value == b[j].value) {
j++;
c[j] = b[j].serial;
}
}
c[j] = -1;
}
/* Code taken from ping.c */
static int
isqrt(int n)
{
int y, x = 1;
if (n == 0)
return (0);
do { /* newton was a stinker */
y = x;
x = n / x;
x += y;
x /= 2;
} while ((x - y) > 1 || (x - y) < -1);
return (x);
}
static int
stone(int *a, int n, int *b, int *c, int flags)
{
int i, k, y, j, l;
int oldc, tc, oldl;
u_int numtries;
/* XXX move the isqrt() out of the macro to avoid multiple calls */
const u_int bound = (flags & D_MINIMAL) ? UINT_MAX :
MAX(256, isqrt(n));
k = 0;
c[0] = newcand(0, 0, 0);
for (i = 1; i <= n; i++) {
j = a[i];
if (j == 0)
continue;
y = -b[j];
oldl = 0;
oldc = c[0];
numtries = 0;
do {
if (y <= clist[oldc].y)
continue;
l = search(c, k, y);
if (l != oldl + 1)
oldc = c[l - 1];
if (l <= k) {
if (clist[c[l]].y <= y)
continue;
tc = c[l];
c[l] = newcand(i, y, oldc);
oldc = tc;
oldl = l;
numtries++;
} else {
c[l] = newcand(i, y, oldc);
k++;
break;
}
} while ((y = b[++j]) > 0 && numtries < bound);
}
return (k);
}
static int
newcand(int x, int y, int pred)
{
struct cand *q;
if (clen == clistlen) {
clistlen = clistlen * 11 / 10;
clist = xrealloc(clist, clistlen, sizeof(*clist));
}
q = clist + clen;
q->x = x;
q->y = y;
q->pred = pred;
return (clen++);
}
static int
search(int *c, int k, int y)
{
int i, j, l, t;
if (clist[c[k]].y < y) /* quick look for typical case */
return (k + 1);
i = 0;
j = k + 1;
for (;;) {
l = (i + j) / 2;
if (l <= i)
break;
t = clist[c[l]].y;
if (t > y)
j = l;
else if (t < y)
i = l;
else
return (l);
}
return (l + 1);
}
static void
unravel(int p)
{
struct cand *q;
int i;
for (i = 0; i <= len[0]; i++)
J[i] = i <= pref ? i :
i > len[0] - suff ? i + len[1] - len[0] : 0;
for (q = clist + p; q->y != 0; q = clist + q->pred)
J[q->x + pref] = q->y + pref;
}
/*
* Check does double duty:
* 1. ferret out any fortuitous correspondences due
* to confounding by hashing (which result in "jackpot")
* 2. collect random access indexes to the two files
*/
static void
check(FILE *f1, FILE *f2, int flags)
{
int i, j, jackpot, c, d;
long ctold, ctnew;
rewind(f1);
rewind(f2);
j = 1;
ixold[0] = ixnew[0] = 0;
jackpot = 0;
ctold = ctnew = 0;
for (i = 1; i <= len[0]; i++) {
if (J[i] == 0) {
ixold[i] = ctold += skipline(f1);
continue;
}
while (j < J[i]) {
ixnew[j] = ctnew += skipline(f2);
j++;
}
if (flags & (D_FOLDBLANKS|D_IGNOREBLANKS|D_IGNORECASE)) {
for (;;) {
c = getc(f1);
d = getc(f2);
/*
* GNU diff ignores a missing newline
* in one file for -b or -w.
*/
if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) &&
((c == EOF && d == '\n') ||
(c == '\n' && d == EOF))) {
break;
}
ctold++;
ctnew++;
if ((flags & D_FOLDBLANKS) && isspace(c) &&
isspace(d)) {
do {
if (c == '\n')
break;
ctold++;
} while (isspace(c = getc(f1)));
do {
if (d == '\n')
break;
ctnew++;
} while (isspace(d = getc(f2)));
} else if ((flags & D_IGNOREBLANKS)) {
while (isspace(c) && c != '\n') {
c = getc(f1);
ctold++;
}
while (isspace(d) && d != '\n') {
d = getc(f2);
ctnew++;
}
}
if (chrtran[c] != chrtran[d]) {
jackpot++;
J[i] = 0;
if (c != '\n' && c != EOF)
ctold += skipline(f1);
if (d != '\n' && c != EOF)
ctnew += skipline(f2);
break;
}
if (c == '\n' || c == EOF)
break;
}
} else {
for (;;) {
ctold++;
ctnew++;
if ((c = getc(f1)) != (d = getc(f2))) {
/* jackpot++; */
J[i] = 0;
if (c != '\n' && c != EOF)
ctold += skipline(f1);
if (d != '\n' && c != EOF)
ctnew += skipline(f2);
break;
}
if (c == '\n' || c == EOF)
break;
}
}
ixold[i] = ctold;
ixnew[j] = ctnew;
j++;
}
for (; j <= len[1]; j++)
ixnew[j] = ctnew += skipline(f2);
/*
* if (jackpot)
* fprintf(stderr, "jackpot\n");
*/
}
/* shellsort CACM #201 */
static void
sort(struct line *a, int n)
{
struct line *ai, *aim, w;
int j, m = 0, k;
if (n == 0)
return;
for (j = 1; j <= n; j *= 2)
m = 2 * j - 1;
for (m /= 2; m != 0; m /= 2) {
k = n - m;
for (j = 1; j <= k; j++) {
for (ai = &a[j]; ai > a; ai -= m) {
aim = &ai[m];
if (aim < ai)
break; /* wraparound */
if (aim->value > ai[0].value ||
(aim->value == ai[0].value &&
aim->serial > ai[0].serial))
break;
w.value = ai[0].value;
ai[0].value = aim->value;
aim->value = w.value;
w.serial = ai[0].serial;
ai[0].serial = aim->serial;
aim->serial = w.serial;
}
}
}
}
static void
unsort(struct line *f, int l, int *b)
{
int *a, i;
a = xcalloc(l + 1, sizeof(*a));
for (i = 1; i <= l; i++)
a[f[i].serial] = f[i].value;
for (i = 1; i <= l; i++)
b[i] = a[i];
xfree(a);
}
static int
skipline(FILE *f)
{
int i, c;
for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
continue;
return (i);
}
static void
output(FILE *f1, FILE *f2, int flags)
{
int m, i0, i1, j0, j1;
rewind(f1);
rewind(f2);
m = len[0];
J[0] = 0;
J[m + 1] = len[1] + 1;
for (i0 = 1; i0 <= m; i0 = i1 + 1) {
while (i0 <= m && J[i0] == J[i0 - 1] + 1)
i0++;
j0 = J[i0 - 1] + 1;
i1 = i0 - 1;
while (i1 < m && J[i1 + 1] == 0)
i1++;
j1 = J[i1 + 1] - 1;
J[i1] = j1;
change(f1, f2, i0, i1, j0, j1, flags);
}
if (m == 0)
change(f1, f2, 1, 0, 1, len[1], flags);
if (diff_format == D_IFDEF) {
for (;;) {
#define c i0
if ((c = getc(f1)) == EOF)
return;
diff_output("%c", c);
}
#undef c
}
if (anychange != 0) {
if (diff_format == D_CONTEXT)
dump_context_vec(f1, f2, flags);
else if (diff_format == D_UNIFIED)
dump_unified_vec(f1, f2, flags);
}
}
static void
range(int a, int b, char *separator)
{
diff_output("%d", a > b ? b : a);
if (a < b)
diff_output("%s%d", separator, b);
}
static void
uni_range(int a, int b)
{
if (a < b)
diff_output("%d,%d", a, b - a + 1);
else if (a == b)
diff_output("%d", b);
else
diff_output("%d,0", b);
}
static char *
preadline(int fd, size_t rlen, off_t off)
{
char *line;
ssize_t nr;
line = xmalloc(rlen + 1);
if ((nr = pread(fd, line, rlen, off)) < 0) {
warn("preadline failed");
xfree(line);
return (NULL);
}
line[nr] = '\0';
return (line);
}
static int
ignoreline(char *line)
{
int ret;
ret = regexec(diff_ignore_re, line, 0, NULL, 0);
xfree(line);
return (ret == 0); /* if it matched, it should be ignored. */
}
/*
* Indicate that there is a difference between lines a and b of the from file
* to get to lines c to d of the to file. If a is greater then b then there
* are no lines in the from file involved and this means that there were
* lines appended (beginning at b). If c is greater than d then there are
* lines missing from the to file.
*/
static void
change(FILE *f1, FILE *f2, int a, int b, int c, int d, int flags)
{
static size_t max_context = 64;
char buf[64];
struct tm *t;
int i;
if (diff_format != D_IFDEF && a > b && c > d)
return;
if (diff_ignore_re != NULL) {
char *line;
/*
* All lines in the change, insert, or delete must
* match an ignore pattern for the change to be
* ignored.
*/
if (a <= b) { /* Changes and deletes. */
for (i = a; i <= b; i++) {
line = preadline(fileno(f1),
ixold[i] - ixold[i - 1], ixold[i - 1]);
if (!ignoreline(line))
goto proceed;
}
}
if (a > b || c <= d) { /* Changes and inserts. */
for (i = c; i <= d; i++) {
line = preadline(fileno(f2),
ixnew[i] - ixnew[i - 1], ixnew[i - 1]);
if (!ignoreline(line))
goto proceed;
}
}
return;
}
proceed:
if (diff_format == D_CONTEXT || diff_format == D_UNIFIED) {
/*
* Allocate change records as needed.
*/
if (context_vec_ptr == context_vec_end - 1) {
ptrdiff_t offset = context_vec_ptr - context_vec_start;
max_context <<= 1;
context_vec_start = xrealloc(context_vec_start,
max_context, sizeof(*context_vec_start));
context_vec_end = context_vec_start + max_context;
context_vec_ptr = context_vec_start + offset;
}
if (anychange == 0) {
/*
* Print the context/unidiff header first time through.
*/
t = localtime(&stb1.st_mtime);
(void)strftime(buf, sizeof(buf),
"%Y/%m/%d %H:%M:%S", t);
diff_output("%s %s %s",
diff_format == D_CONTEXT ? "***" : "---", diff_file,
buf);
if (diff_rev1 != NULL) {
rcsnum_tostr(diff_rev1, buf, sizeof(buf));
diff_output("\t%s", buf);
}
printf("\n");
t = localtime(&stb2.st_mtime);
(void)strftime(buf, sizeof(buf),
"%Y/%m/%d %H:%M:%S", t);
diff_output("%s %s %s",
diff_format == D_CONTEXT ? "---" : "+++", diff_file,
buf);
if (diff_rev2 != NULL) {
rcsnum_tostr(diff_rev2, buf, sizeof(buf));
diff_output("\t%s", buf);
}
printf("\n");
anychange = 1;
} else if (a > context_vec_ptr->b + (2 * diff_context) + 1 &&
c > context_vec_ptr->d + (2 * diff_context) + 1) {
/*
* If this change is more than 'diff_context' lines from the
* previous change, dump the record and reset it.
*/
if (diff_format == D_CONTEXT)
dump_context_vec(f1, f2, flags);
else
dump_unified_vec(f1, f2, flags);
}
context_vec_ptr++;
context_vec_ptr->a = a;
context_vec_ptr->b = b;
context_vec_ptr->c = c;
context_vec_ptr->d = d;
return;
}
if (anychange == 0)
anychange = 1;
switch (diff_format) {
case D_BRIEF:
return;
case D_NORMAL:
range(a, b, ",");
diff_output("%c", a > b ? 'a' : c > d ? 'd' : 'c');
if (diff_format == D_NORMAL)
range(c, d, ",");
diff_output("\n");
break;
case D_RCSDIFF:
if (a > b)
diff_output("a%d %d\n", b, d - c + 1);
else {
diff_output("d%d %d\n", a, b - a + 1);
if (!(c > d)) /* add changed lines */
diff_output("a%d %d\n", b, d - c + 1);
}
break;
}
if (diff_format == D_NORMAL || diff_format == D_IFDEF) {
fetch(ixold, a, b, f1, '<', 1, flags);
if (a <= b && c <= d && diff_format == D_NORMAL)
diff_output("---\n");
}
fetch(ixnew, c, d, f2, diff_format == D_NORMAL ? '>' : '\0', 0, flags);
if (inifdef) {
diff_output("#endif /* %s */\n", ifdefname);
inifdef = 0;
}
}
static void
fetch(long *f, int a, int b, FILE *lb, int ch, int oldfile, int flags)
{
long j, nc;
int i, c, col;
/*
* When doing #ifdef's, copy down to current line
* if this is the first file, so that stuff makes it to output.
*/
if (diff_format == D_IFDEF && oldfile) {
long curpos = ftell(lb);
/* print through if append (a>b), else to (nb: 0 vs 1 orig) */
nc = f[a > b ? b : a - 1] - curpos;
for (i = 0; i < nc; i++)
diff_output("%c", getc(lb));
}
if (a > b)
return;
if (diff_format == D_IFDEF) {
if (inifdef) {
diff_output("#else /* %s%s */\n",
oldfile == 1 ? "!" : "", ifdefname);
} else {
if (oldfile)
diff_output("#ifndef %s\n", ifdefname);
else
diff_output("#ifdef %s\n", ifdefname);
}
inifdef = 1 + oldfile;
}
for (i = a; i <= b; i++) {
fseek(lb, f[i - 1], SEEK_SET);
nc = f[i] - f[i - 1];
if (diff_format != D_IFDEF && ch != '\0') {
diff_output("%c", ch);
if (diff_format != D_UNIFIED)
diff_output(" ");
}
col = 0;
for (j = 0; j < nc; j++) {
if ((c = getc(lb)) == EOF) {
if (diff_format == D_RCSDIFF)
warn("No newline at end of file");
else
diff_output("\n\\ No newline at end of "
"file");
return;
}
if (c == '\t' && (flags & D_EXPANDTABS)) {
do {
diff_output(" ");
} while (++col & 7);
} else {
diff_output("%c", c);
col++;
}
}
}
}
/*
* Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
*/
static int
readhash(FILE *f, int flags)
{
int i, t, space;
int sum;
sum = 1;
space = 0;
if ((flags & (D_FOLDBLANKS|D_IGNOREBLANKS)) == 0) {
if (flags & D_IGNORECASE)
for (i = 0; (t = getc(f)) != '\n'; i++) {
if (t == EOF) {
if (i == 0)
return (0);
break;
}
sum = sum * 127 + chrtran[t];
}
else
for (i = 0; (t = getc(f)) != '\n'; i++) {
if (t == EOF) {
if (i == 0)
return (0);
break;
}
sum = sum * 127 + t;
}
} else {
for (i = 0;;) {
switch (t = getc(f)) {
case '\t':
case '\r':
case '\v':
case '\f':
case ' ':
space++;
continue;
default:
if (space && (flags & D_IGNOREBLANKS) == 0) {
i++;
space = 0;
}
sum = sum * 127 + chrtran[t];
i++;
continue;
case EOF:
if (i == 0)
return (0);
/* FALLTHROUGH */
case '\n':
break;
}
break;
}
}
/*
* There is a remote possibility that we end up with a zero sum.
* Zero is used as an EOF marker, so return 1 instead.
*/
return (sum == 0 ? 1 : sum);
}
static int
asciifile(FILE *f)
{
unsigned char buf[BUFSIZ];
size_t i, cnt;
if (f == NULL)
return (1);
rewind(f);
cnt = fread(buf, 1, sizeof(buf), f);
for (i = 0; i < cnt; i++)
if (!isprint(buf[i]) && !isspace(buf[i]))
return (0);
return (1);
}
#define begins_with(s, pre) (strncmp(s, pre, sizeof(pre)-1) == 0)
static char *
match_function(const long *f, int pos, FILE *fp)
{
unsigned char buf[FUNCTION_CONTEXT_SIZE];
size_t nc;
int last = lastline;
char *state = NULL;
lastline = pos;
while (pos > last) {
fseek(fp, f[pos - 1], SEEK_SET);
nc = f[pos] - f[pos - 1];
if (nc >= sizeof(buf))
nc = sizeof(buf) - 1;
nc = fread(buf, 1, nc, fp);
if (nc > 0) {
buf[nc] = '\0';
buf[strcspn(buf, "\n")] = '\0';
if (isalpha(buf[0]) || buf[0] == '_' || buf[0] == '$') {
if (begins_with(buf, "private:")) {
if (!state)
state = " (private)";
} else if (begins_with(buf, "protected:")) {
if (!state)
state = " (protected)";
} else if (begins_with(buf, "public:")) {
if (!state)
state = " (public)";
} else {
if (strlcpy(lastbuf, buf,
sizeof(lastbuf)) >= sizeof(lastbuf))
errx(1,
"match_function: strlcpy");
lastmatchline = pos;
return lastbuf;
}
}
}
pos--;
}
return lastmatchline > 0 ? lastbuf : NULL;
}
/* dump accumulated "context" diff changes */
static void
dump_context_vec(FILE *f1, FILE *f2, int flags)
{
struct context_vec *cvp = context_vec_start;
int lowa, upb, lowc, upd, do_output;
int a, b, c, d;
char ch, *f;
if (context_vec_start > context_vec_ptr)
return;
b = d = 0; /* gcc */
lowa = MAX(1, cvp->a - diff_context);
upb = MIN(len[0], context_vec_ptr->b + diff_context);
lowc = MAX(1, cvp->c - diff_context);
upd = MIN(len[1], context_vec_ptr->d + diff_context);
diff_output("***************");
if ((flags & D_PROTOTYPE)) {
f = match_function(ixold, lowa-1, f1);
if (f != NULL) {
diff_output(" ");
diff_output("%s", f);
}
}
diff_output("\n*** ");
range(lowa, upb, ",");
diff_output(" ****\n");
/*
* Output changes to the "old" file. The first loop suppresses
* output if there were no changes to the "old" file (we'll see
* the "old" lines as context in the "new" list).
*/
do_output = 0;
for (; cvp <= context_vec_ptr; cvp++)
if (cvp->a <= cvp->b) {
cvp = context_vec_start;
do_output++;
break;
}
if (do_output) {
while (cvp <= context_vec_ptr) {
a = cvp->a;
b = cvp->b;
c = cvp->c;
d = cvp->d;
if (a <= b && c <= d)
ch = 'c';
else
ch = (a <= b) ? 'd' : 'a';
if (ch == 'a')
fetch(ixold, lowa, b, f1, ' ', 0, flags);
else {
fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
fetch(ixold, a, b, f1,
ch == 'c' ? '!' : '-', 0, flags);
}
lowa = b + 1;
cvp++;
}
fetch(ixold, b + 1, upb, f1, ' ', 0, flags);
}
/* output changes to the "new" file */
diff_output("--- ");
range(lowc, upd, ",");
diff_output(" ----\n");
do_output = 0;
for (cvp = context_vec_start; cvp <= context_vec_ptr; cvp++)
if (cvp->c <= cvp->d) {
cvp = context_vec_start;
do_output++;
break;
}
if (do_output) {
while (cvp <= context_vec_ptr) {
a = cvp->a;
b = cvp->b;
c = cvp->c;
d = cvp->d;
if (a <= b && c <= d)
ch = 'c';
else
ch = (a <= b) ? 'd' : 'a';
if (ch == 'd')
fetch(ixnew, lowc, d, f2, ' ', 0, flags);
else {
fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
fetch(ixnew, c, d, f2,
ch == 'c' ? '!' : '+', 0, flags);
}
lowc = d + 1;
cvp++;
}
fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
}
context_vec_ptr = context_vec_start - 1;
}
/* dump accumulated "unified" diff changes */
static void
dump_unified_vec(FILE *f1, FILE *f2, int flags)
{
struct context_vec *cvp = context_vec_start;
int lowa, upb, lowc, upd;
int a, b, c, d;
char ch, *f;
if (context_vec_start > context_vec_ptr)
return;
b = d = 0; /* gcc */
lowa = MAX(1, cvp->a - diff_context);
upb = MIN(len[0], context_vec_ptr->b + diff_context);
lowc = MAX(1, cvp->c - diff_context);
upd = MIN(len[1], context_vec_ptr->d + diff_context);
diff_output("@@ -");
uni_range(lowa, upb);
diff_output(" +");
uni_range(lowc, upd);
diff_output(" @@");
if ((flags & D_PROTOTYPE)) {
f = match_function(ixold, lowa-1, f1);
if (f != NULL) {
diff_output(" ");
diff_output("%s", f);
}
}
diff_output("\n");
/*
* Output changes in "unified" diff format--the old and new lines
* are printed together.
*/
for (; cvp <= context_vec_ptr; cvp++) {
a = cvp->a;
b = cvp->b;
c = cvp->c;
d = cvp->d;
/*
* c: both new and old changes
* d: only changes in the old file
* a: only changes in the new file
*/
if (a <= b && c <= d)
ch = 'c';
else
ch = (a <= b) ? 'd' : 'a';
switch (ch) {
case 'c':
fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
fetch(ixold, a, b, f1, '-', 0, flags);
fetch(ixnew, c, d, f2, '+', 0, flags);
break;
case 'd':
fetch(ixold, lowa, a - 1, f1, ' ', 0, flags);
fetch(ixold, a, b, f1, '-', 0, flags);
break;
case 'a':
fetch(ixnew, lowc, c - 1, f2, ' ', 0, flags);
fetch(ixnew, c, d, f2, '+', 0, flags);
break;
}
lowa = b + 1;
lowc = d + 1;
}
fetch(ixnew, d + 1, upd, f2, ' ', 0, flags);
context_vec_ptr = context_vec_start - 1;
}
void
diff_output(const char *fmt, ...)
{
va_list vap;
int i;
char *str;
va_start(vap, fmt);
i = vasprintf(&str, fmt, vap);
va_end(vap);
if (i == -1)
err(1, "diff_output");
if (diffbuf != NULL)
rcs_buf_append(diffbuf, str, strlen(str));
else
printf("%s", str);
xfree(str);
}