git/builtin-diff.c
Junio C Hamano fbbdbfc3cc refresh_index_quietly(): express "optional" nature of index writing better
The point of the part of the code this patch touches is that if
we modified the active_cache, we try to write it out and make it
the index file for later users to use by calling
"commit_locked_index", but we do not really care about the
failure from this sequence because it is done purely as an
optimization.

The original code called three functions primarily for their
side effects but as condition of an if statement, which is
admittedly a bad style.

Incidentally, it squelches an "empty if body" warning from gcc.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-08 16:26:23 -08:00

373 lines
8.9 KiB
C

/*
* Builtin "git diff"
*
* Copyright (c) 2006 Junio C Hamano
*/
#include "cache.h"
#include "commit.h"
#include "blob.h"
#include "tag.h"
#include "diff.h"
#include "diffcore.h"
#include "revision.h"
#include "log-tree.h"
#include "builtin.h"
struct blobinfo {
unsigned char sha1[20];
const char *name;
unsigned mode;
};
static const char builtin_diff_usage[] =
"git-diff <options> <rev>{0,2} -- <path>*";
static void stuff_change(struct diff_options *opt,
unsigned old_mode, unsigned new_mode,
const unsigned char *old_sha1,
const unsigned char *new_sha1,
const char *old_name,
const char *new_name)
{
struct diff_filespec *one, *two;
if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
!hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
return;
if (opt->reverse_diff) {
unsigned tmp;
const unsigned char *tmp_u;
const char *tmp_c;
tmp = old_mode; old_mode = new_mode; new_mode = tmp;
tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
tmp_c = old_name; old_name = new_name; new_name = tmp_c;
}
one = alloc_filespec(old_name);
two = alloc_filespec(new_name);
fill_filespec(one, old_sha1, old_mode);
fill_filespec(two, new_sha1, new_mode);
/* NEEDSWORK: shouldn't this part of diffopt??? */
diff_queue(&diff_queued_diff, one, two);
}
static int builtin_diff_b_f(struct rev_info *revs,
int argc, const char **argv,
struct blobinfo *blob,
const char *path)
{
/* Blob vs file in the working tree*/
struct stat st;
if (argc > 1)
usage(builtin_diff_usage);
if (lstat(path, &st))
die("'%s': %s", path, strerror(errno));
if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
die("'%s': not a regular file or symlink", path);
if (blob[0].mode == S_IFINVALID)
blob[0].mode = canon_mode(st.st_mode);
stuff_change(&revs->diffopt,
blob[0].mode, canon_mode(st.st_mode),
blob[0].sha1, null_sha1,
path, path);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return 0;
}
static int builtin_diff_blobs(struct rev_info *revs,
int argc, const char **argv,
struct blobinfo *blob)
{
unsigned mode = canon_mode(S_IFREG | 0644);
if (argc > 1)
usage(builtin_diff_usage);
if (blob[0].mode == S_IFINVALID)
blob[0].mode = mode;
if (blob[1].mode == S_IFINVALID)
blob[1].mode = mode;
stuff_change(&revs->diffopt,
blob[0].mode, blob[1].mode,
blob[0].sha1, blob[1].sha1,
blob[0].name, blob[1].name);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return 0;
}
static int builtin_diff_index(struct rev_info *revs,
int argc, const char **argv)
{
int cached = 0;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--cached"))
cached = 1;
else
usage(builtin_diff_usage);
argv++; argc--;
}
/*
* Make sure there is one revision (i.e. pending object),
* and there is no revision filtering parameters.
*/
if (revs->pending.nr != 1 ||
revs->max_count != -1 || revs->min_age != -1 ||
revs->max_age != -1)
usage(builtin_diff_usage);
if (read_cache() < 0) {
perror("read_cache");
return -1;
}
return run_diff_index(revs, cached);
}
static int builtin_diff_tree(struct rev_info *revs,
int argc, const char **argv,
struct object_array_entry *ent)
{
const unsigned char *(sha1[2]);
int swap = 0;
if (argc > 1)
usage(builtin_diff_usage);
/* We saw two trees, ent[0] and ent[1].
* if ent[1] is uninteresting, they are swapped
*/
if (ent[1].item->flags & UNINTERESTING)
swap = 1;
sha1[swap] = ent[0].item->sha1;
sha1[1-swap] = ent[1].item->sha1;
diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
log_tree_diff_flush(revs);
return 0;
}
static int builtin_diff_combined(struct rev_info *revs,
int argc, const char **argv,
struct object_array_entry *ent,
int ents)
{
const unsigned char (*parent)[20];
int i;
if (argc > 1)
usage(builtin_diff_usage);
if (!revs->dense_combined_merges && !revs->combine_merges)
revs->dense_combined_merges = revs->combine_merges = 1;
parent = xmalloc(ents * sizeof(*parent));
/* Again, the revs are all reverse */
for (i = 0; i < ents; i++)
hashcpy((unsigned char *)(parent + i),
ent[ents - 1 - i].item->sha1);
diff_tree_combined(parent[0], parent + 1, ents - 1,
revs->dense_combined_merges, revs);
return 0;
}
void add_head(struct rev_info *revs)
{
unsigned char sha1[20];
struct object *obj;
if (get_sha1("HEAD", sha1))
return;
obj = parse_object(sha1);
if (!obj)
return;
add_pending_object(revs, obj, "HEAD");
}
static void refresh_index_quietly(void)
{
struct lock_file *lock_file;
int fd;
lock_file = xcalloc(1, sizeof(struct lock_file));
fd = hold_locked_index(lock_file, 0);
if (fd < 0)
return;
discard_cache();
read_cache();
refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
if (active_cache_changed &&
!write_cache(fd, active_cache, active_nr) && !close(fd))
commit_locked_index(lock_file);
rollback_lock_file(lock_file);
}
int cmd_diff(int argc, const char **argv, const char *prefix)
{
int i;
struct rev_info rev;
struct object_array_entry ent[100];
int ents = 0, blobs = 0, paths = 0;
const char *path = NULL;
struct blobinfo blob[2];
int nongit = 0;
int result = 0;
/*
* We could get N tree-ish in the rev.pending_objects list.
* Also there could be M blobs there, and P pathspecs.
*
* N=0, M=0:
* cache vs files (diff-files)
* N=0, M=2:
* compare two random blobs. P must be zero.
* N=0, M=1, P=1:
* compare a blob with a working tree file.
*
* N=1, M=0:
* tree vs cache (diff-index --cached)
*
* N=2, M=0:
* tree vs tree (diff-tree)
*
* Other cases are errors.
*/
prefix = setup_git_directory_gently(&nongit);
git_config(git_diff_ui_config);
init_revisions(&rev, prefix);
rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
if (!setup_diff_no_index(&rev, argc, argv, nongit, prefix))
argc = 0;
else
argc = setup_revisions(argc, argv, &rev, NULL);
if (!rev.diffopt.output_format) {
rev.diffopt.output_format = DIFF_FORMAT_PATCH;
if (diff_setup_done(&rev.diffopt) < 0)
die("diff_setup_done failed");
}
rev.diffopt.allow_external = 1;
rev.diffopt.recursive = 1;
/* If the user asked for our exit code then don't start a
* pager or we would end up reporting its exit code instead.
*/
if (!rev.diffopt.exit_with_status)
setup_pager();
/* Do we have --cached and not have a pending object, then
* default to HEAD by hand. Eek.
*/
if (!rev.pending.nr) {
int i;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--"))
break;
else if (!strcmp(arg, "--cached")) {
add_head(&rev);
if (!rev.pending.nr)
die("No HEAD commit to compare with (yet)");
break;
}
}
}
for (i = 0; i < rev.pending.nr; i++) {
struct object_array_entry *list = rev.pending.objects+i;
struct object *obj = list->item;
const char *name = list->name;
int flags = (obj->flags & UNINTERESTING);
if (!obj->parsed)
obj = parse_object(obj->sha1);
obj = deref_tag(obj, NULL, 0);
if (!obj)
die("invalid object '%s' given.", name);
if (obj->type == OBJ_COMMIT)
obj = &((struct commit *)obj)->tree->object;
if (obj->type == OBJ_TREE) {
if (ARRAY_SIZE(ent) <= ents)
die("more than %d trees given: '%s'",
(int) ARRAY_SIZE(ent), name);
obj->flags |= flags;
ent[ents].item = obj;
ent[ents].name = name;
ents++;
continue;
}
if (obj->type == OBJ_BLOB) {
if (2 <= blobs)
die("more than two blobs given: '%s'", name);
hashcpy(blob[blobs].sha1, obj->sha1);
blob[blobs].name = name;
blob[blobs].mode = list->mode;
blobs++;
continue;
}
die("unhandled object '%s' given.", name);
}
if (rev.prune_data) {
const char **pathspec = rev.prune_data;
while (*pathspec) {
if (!path)
path = *pathspec;
paths++;
pathspec++;
}
}
/*
* Now, do the arguments look reasonable?
*/
if (!ents) {
switch (blobs) {
case 0:
result = run_diff_files_cmd(&rev, argc, argv);
break;
case 1:
if (paths != 1)
usage(builtin_diff_usage);
result = builtin_diff_b_f(&rev, argc, argv, blob, path);
break;
case 2:
if (paths)
usage(builtin_diff_usage);
result = builtin_diff_blobs(&rev, argc, argv, blob);
break;
default:
usage(builtin_diff_usage);
}
}
else if (blobs)
usage(builtin_diff_usage);
else if (ents == 1)
result = builtin_diff_index(&rev, argc, argv);
else if (ents == 2)
result = builtin_diff_tree(&rev, argc, argv, ent);
else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
/* diff A...B where there is one sane merge base between
* A and B. We have ent[0] == merge-base, ent[1] == A,
* and ent[2] == B. Show diff between the base and B.
*/
ent[1] = ent[2];
result = builtin_diff_tree(&rev, argc, argv, ent);
}
else
result = builtin_diff_combined(&rev, argc, argv,
ent, ents);
if (rev.diffopt.exit_with_status)
result = rev.diffopt.has_changes;
if (1 < rev.diffopt.skip_stat_unmatch)
refresh_index_quietly();
return result;
}