git/combine-diff.c
Junio C Hamano d8f4790e6f diff-tree --cc: denser combined diff output for a merge commit.
Building on the previous '-c' (combined) option, '--cc' option
squelches the output further by omitting hunks that consist of
difference with solely one parent.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-28 00:08:28 -08:00

529 lines
12 KiB
C

#include "cache.h"
#include "commit.h"
#include "diff.h"
#include "diffcore.h"
#include "quote.h"
struct path_list {
struct path_list *next;
int len;
char *path;
unsigned char sha1[20];
unsigned char parent_sha1[FLEX_ARRAY][20];
};
static int uninteresting(struct diff_filepair *p)
{
if (diff_unmodified_pair(p))
return 1;
if (!S_ISREG(p->one->mode) || !S_ISREG(p->two->mode))
return 1;
return 0;
}
static struct path_list *intersect_paths(struct path_list *curr,
int n, int num_parent)
{
struct diff_queue_struct *q = &diff_queued_diff;
struct path_list *p;
int i;
if (!n) {
struct path_list *list = NULL, *tail = NULL;
for (i = 0; i < q->nr; i++) {
int len;
const char *path;
if (uninteresting(q->queue[i]))
continue;
path = q->queue[i]->two->path;
len = strlen(path);
p = xmalloc(sizeof(*p) + len + 1 + num_parent * 20);
p->path = (char*) &(p->parent_sha1[num_parent][0]);
memcpy(p->path, path, len);
p->path[len] = 0;
p->len = len;
p->next = NULL;
memcpy(p->sha1, q->queue[i]->two->sha1, 20);
memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
if (!tail)
list = tail = p;
else {
tail->next = p;
p = tail;
}
}
return list;
}
for (p = curr; p; p = p->next) {
int found = 0;
if (!p->len)
continue;
for (i = 0; i < q->nr; i++) {
const char *path;
int len;
if (uninteresting(q->queue[i]))
continue;
path = q->queue[i]->two->path;
len = strlen(path);
if (len == p->len && !memcmp(path, p->path, len)) {
found = 1;
memcpy(p->parent_sha1[n],
q->queue[i]->one->sha1, 20);
break;
}
}
if (!found)
p->len = 0;
}
return curr;
}
struct lline {
struct lline *next;
int len;
unsigned long parent_map;
char line[FLEX_ARRAY];
};
struct sline {
struct lline *lost_head, **lost_tail;
char *bol;
int len;
unsigned long flag;
};
static char *grab_blob(const unsigned char *sha1, unsigned long *size)
{
char *blob;
char type[20];
if (!memcmp(sha1, null_sha1, 20)) {
/* deleted blob */
*size = 0;
return xcalloc(1, 1);
}
blob = read_sha1_file(sha1, type, size);
if (strcmp(type, "blob"))
die("object '%s' is not a blob!", sha1_to_hex(sha1));
return blob;
}
#define TMPPATHLEN 50
#define MAXLINELEN 10240
static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
{
int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
if (fd < 0)
die("unable to create temp-file");
if (write(fd, blob, size) != size)
die("unable to write temp-file");
close(fd);
}
static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
{
unsigned long size;
void *blob;
blob = grab_blob(sha1, &size);
write_to_temp_file(tmpfile, blob, size);
free(blob);
}
static int parse_num(char **cp_p, unsigned int *num_p)
{
char *cp = *cp_p;
unsigned int num = 0;
int read_some;
while ('0' <= *cp && *cp <= '9')
num = num * 10 + *cp++ - '0';
if (!(read_some = cp - *cp_p))
return -1;
*cp_p = cp;
*num_p = num;
return 0;
}
static int parse_hunk_header(char *line, int len,
unsigned int *ob, unsigned int *on,
unsigned int *nb, unsigned int *nn)
{
char *cp;
cp = line + 4;
if (parse_num(&cp, ob)) {
bad_line:
return error("malformed diff output: %s", line);
}
if (*cp == ',') {
cp++;
if (parse_num(&cp, on))
goto bad_line;
}
else
*on = 1;
if (*cp++ != ' ' || *cp++ != '+')
goto bad_line;
if (parse_num(&cp, nb))
goto bad_line;
if (*cp == ',') {
cp++;
if (parse_num(&cp, nn))
goto bad_line;
}
else
*nn = 1;
return -!!memcmp(cp, " @@", 3);
}
static void append_lost(struct sline *sline, int n, const char *line)
{
struct lline *lline;
int len = strlen(line);
unsigned long this_mask = (1UL<<n);
if (line[len-1] == '\n')
len--;
/* Check to see if we can squash things */
if (sline->lost_head) {
struct lline *last_one = NULL;
/* We cannot squash it with earlier one */
for (lline = sline->lost_head;
lline;
lline = lline->next)
if (lline->parent_map & this_mask)
last_one = lline;
lline = last_one ? last_one->next : sline->lost_head;
while (lline) {
if (lline->len == len &&
!memcmp(lline->line, line, len)) {
lline->parent_map |= this_mask;
return;
}
lline = lline->next;
}
}
lline = xmalloc(sizeof(*lline) + len + 1);
lline->len = len;
lline->next = NULL;
lline->parent_map = this_mask;
memcpy(lline->line, line, len);
lline->line[len] = 0;
if (sline->lost_head)
*(sline->lost_tail) = lline;
else
sline->lost_head = lline;
sline->lost_tail = &lline->next;
}
static void combine_diff(const unsigned char *parent, const char *ourtmp,
struct sline *sline, int cnt, int n)
{
FILE *in;
char parent_tmp[TMPPATHLEN];
char cmd[TMPPATHLEN * 2 + 1024];
char line[MAXLINELEN];
unsigned int lno, ob, on, nb, nn;
unsigned long pmask = ~(1UL << n);
struct sline *lost_bucket = NULL;
write_temp_blob(parent_tmp, parent);
sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
parent_tmp, ourtmp);
in = popen(cmd, "r");
if (!in)
return;
lno = 1;
while (fgets(line, sizeof(line), in) != NULL) {
int len = strlen(line);
if (5 < len && !memcmp("@@ -", line, 4)) {
if (parse_hunk_header(line, len,
&ob, &on, &nb, &nn))
break;
lno = nb;
if (!nb) {
/* @@ -1,2 +0,0 @@ to remove the
* first two lines...
*/
nb = 1;
}
lost_bucket = &sline[nb-1]; /* sline is 0 based */
continue;
}
if (!lost_bucket)
continue;
switch (line[0]) {
case '-':
append_lost(lost_bucket, n, line+1);
break;
case '+':
sline[lno-1].flag &= pmask;
lno++;
break;
}
}
fclose(in);
unlink(parent_tmp);
}
static unsigned long context = 3;
static char combine_marker = '@';
static int interesting(struct sline *sline, unsigned long all_mask)
{
return ((sline->flag & all_mask) != all_mask || sline->lost_head);
}
static unsigned long line_diff_parents(struct sline *sline, unsigned long all_mask)
{
/*
* Look at the line and see from which parents we have difference.
* Lower bits of sline->flag records if the parent had this line,
* so XOR with all_mask gives us on-bits for parents we have
* differences with.
*/
unsigned long parents = (sline->flag ^ all_mask);
if (sline->lost_head) {
struct lline *ll;
for (ll = sline->lost_head; ll; ll = ll->next)
parents |= ll->parent_map;
}
return parents & all_mask;
}
static void make_hunks(struct sline *sline, unsigned long cnt,
int num_parent, int dense)
{
unsigned long all_mask = (1UL<<num_parent) - 1;
unsigned long mark = (1UL<<num_parent);
unsigned long i;
i = 0;
while (i < cnt) {
if (interesting(&sline[i], all_mask)) {
unsigned long j = (context < i) ? i - context : 0;
while (j <= i)
sline[j++].flag |= mark;
while (++i < cnt) {
if (!interesting(&sline[i], all_mask))
break;
sline[i].flag |= mark;
}
j = (i + context < cnt) ? i + context : cnt;
while (i < j)
sline[i++].flag |= mark;
continue;
}
i++;
}
if (!dense)
return;
/* Look at each hunk, and if it contains changes from only
* one parent, mark that uninteresting.
*/
i = 0;
while (i < cnt) {
int j, hunk_end, diffs;
unsigned long parents;
while (i < cnt && !(sline[i].flag & mark))
i++;
if (cnt <= i)
break; /* No more interesting hunks */
for (hunk_end = i + 1; hunk_end < cnt; hunk_end++)
if (!(sline[hunk_end].flag & mark))
break;
/* [i..hunk_end) are interesting. Now is it from
* only one parent?
* If lost lines are only from one parent and
* remaining lines existed in parents other than
* that parent, then the hunk is not that interesting.
*/
parents = 0;
diffs = 0;
for (j = i; j < hunk_end; j++)
parents |= line_diff_parents(sline + j, all_mask);
/* Now, how many bits from [0..num_parent) are on? */
for (j = 0; j < num_parent; j++) {
if (parents & (1UL<<j))
diffs++;
}
if (diffs < 2) {
/* This hunk is not that interesting after all */
for (j = i; j < hunk_end; j++)
sline[j].flag &= ~mark;
}
i = hunk_end;
}
}
static void dump_sline(struct sline *sline, int cnt, int num_parent)
{
unsigned long mark = (1UL<<num_parent);
int i;
int lno = 0;
while (1) {
struct sline *sl = &sline[lno];
int hunk_end;
while (lno < cnt && !(sline[lno].flag & mark))
lno++;
if (cnt <= lno)
break;
for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
if (!(sline[hunk_end].flag & mark))
break;
for (i = 0; i <= num_parent; i++) putchar(combine_marker);
printf(" +%d,%d ", lno+1, hunk_end-lno);
for (i = 0; i <= num_parent; i++) putchar(combine_marker);
putchar('\n');
while (lno < hunk_end) {
struct lline *ll;
int j;
sl = &sline[lno++];
ll = sl->lost_head;
while (ll) {
for (j = 0; j < num_parent; j++) {
if (ll->parent_map & (1UL<<j))
putchar('-');
else
putchar(' ');
}
putchar(' ');
puts(ll->line);
ll = ll->next;
}
for (j = 0; j < num_parent; j++) {
if ((1UL<<j) & sl->flag)
putchar(' ');
else
putchar('+');
}
printf(" %.*s\n", sl->len, sl->bol);
}
}
}
static void show_combined_diff(struct path_list *elem, int num_parent,
int dense)
{
unsigned long size, cnt, lno;
char *result, *cp, *ep;
struct sline *sline; /* survived lines */
int i;
char ourtmp[TMPPATHLEN];
/* Read the result of merge first */
result = grab_blob(elem->sha1, &size);
write_to_temp_file(ourtmp, result, size);
for (cnt = 0, cp = result; cp - result < size; cp++) {
if (*cp == '\n')
cnt++;
}
if (result[size-1] != '\n')
cnt++; /* incomplete line */
sline = xcalloc(cnt, sizeof(*sline));
ep = result;
sline[0].bol = result;
for (lno = 0, cp = result; cp - result < size; cp++) {
if (*cp == '\n') {
sline[lno].len = cp - sline[lno].bol;
sline[lno].flag = (1UL<<num_parent) - 1;
lno++;
if (lno < cnt)
sline[lno].bol = cp + 1;
}
}
if (result[size-1] != '\n') {
sline[cnt-1].len = size - (sline[cnt-1].bol - result);
sline[cnt-1].flag = (1UL<<num_parent) - 1;
}
for (i = 0; i < num_parent; i++)
combine_diff(elem->parent_sha1[i], ourtmp, sline, cnt, i);
make_hunks(sline, cnt, num_parent, dense);
dump_sline(sline, cnt, num_parent);
unlink(ourtmp);
free(result);
for (i = 0; i < cnt; i++) {
if (sline[i].lost_head) {
struct lline *ll = sline[i].lost_head;
while (ll) {
struct lline *tmp = ll;
ll = ll->next;
free(tmp);
}
}
}
free(sline);
}
int diff_tree_combined_merge(const unsigned char *sha1,
const char *header,
int show_empty_merge, int dense)
{
struct commit *commit = lookup_commit(sha1);
struct diff_options diffopts;
struct commit_list *parents;
struct path_list *p, *paths = NULL;
int num_parent, i, num_paths;
diff_setup(&diffopts);
diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
diffopts.recursive = 1;
/* count parents */
for (parents = commit->parents, num_parent = 0;
parents;
parents = parents->next, num_parent++)
; /* nothing */
/* find set of paths that everybody touches */
for (parents = commit->parents, i = 0;
parents;
parents = parents->next, i++) {
struct commit *parent = parents->item;
diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
&diffopts);
paths = intersect_paths(paths, i, num_parent);
diff_flush(&diffopts);
}
/* find out surviving paths */
for (num_paths = 0, p = paths; p; p = p->next) {
if (p->len)
num_paths++;
}
if (num_paths || show_empty_merge) {
puts(header);
for (p = paths; p; p = p->next) {
if (!p->len)
continue;
printf("diff --combined ");
if (quote_c_style(p->path, NULL, NULL, 0))
quote_c_style(p->path, NULL, stdout, 0);
else
printf("%s", p->path);
putchar('\n');
show_combined_diff(p, num_parent, dense);
}
}
/* Clean things up */
while (paths) {
struct path_list *tmp = paths;
paths = paths->next;
free(tmp);
}
return 0;
}