git/builtin/diff.c
Nguyễn Thái Ngọc Duy a2b7a3b3a9 diff: support --cached on unborn branches
"git diff --cached" (without revision) used to mean "git diff --cached
HEAD" (i.e. the user was too lazy to type HEAD). This "correctly"
failed when there was no commit yet. But was that correctness useful?

This patch changes the definition of what particular command means.
It is a request to show what _would_ be committed without further "git
add". The internal implementation is the same "git diff --cached HEAD"
when HEAD exists, but when there is no commit yet, it compares the index
with an empty tree object to achieve the desired result.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-07 15:04:30 -08:00

432 lines
11 KiB
C

/*
* Builtin "git diff"
*
* Copyright (c) 2006 Junio C Hamano
*/
#include "cache.h"
#include "color.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"
#include "submodule.h"
struct blobinfo {
unsigned char sha1[20];
const char *name;
unsigned mode;
};
static const char builtin_diff_usage[] =
"git diff [<options>] [<commit> [<commit>]] [--] [<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 (DIFF_OPT_TST(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;
}
if (opt->prefix &&
(strncmp(old_name, opt->prefix, opt->prefix_length) ||
strncmp(new_name, opt->prefix, opt->prefix_length)))
return;
one = alloc_filespec(old_name);
two = alloc_filespec(new_name);
fill_filespec(one, old_sha1, old_mode);
fill_filespec(two, new_sha1, new_mode);
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_errno("failed to stat '%s'", path);
if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
die("'%s': not a regular file or symlink", path);
diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
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") || !strcmp(arg, "--staged"))
cached = 1;
else
usage(builtin_diff_usage);
argv++; argc--;
}
if (!cached)
setup_work_tree();
/*
* 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_preload(revs->diffopt.paths) < 0) {
perror("read_cache_preload");
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));
for (i = 0; i < ents; i++)
hashcpy((unsigned char *)(parent + i), ent[i].item->sha1);
diff_tree_combined(parent[0], parent + 1, ents - 1,
revs->dense_combined_merges, revs);
return 0;
}
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))
commit_locked_index(lock_file);
rollback_lock_file(lock_file);
}
static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
{
int result;
unsigned int options = 0;
while (1 < argc && argv[1][0] == '-') {
if (!strcmp(argv[1], "--base"))
revs->max_count = 1;
else if (!strcmp(argv[1], "--ours"))
revs->max_count = 2;
else if (!strcmp(argv[1], "--theirs"))
revs->max_count = 3;
else if (!strcmp(argv[1], "-q"))
options |= DIFF_SILENT_ON_REMOVED;
else if (!strcmp(argv[1], "-h"))
usage(builtin_diff_usage);
else
return error("invalid option: %s", argv[1]);
argv++; argc--;
}
/*
* "diff --base" should not combine merges because it was not
* asked to. "diff -c" should not densify (if the user wants
* dense one, --cc can be explicitly asked for, or just rely
* on the default).
*/
if (revs->max_count == -1 && !revs->combine_merges &&
(revs->diffopt.output_format & DIFF_FORMAT_PATCH))
revs->combine_merges = revs->dense_combined_merges = 1;
setup_work_tree();
if (read_cache_preload(revs->diffopt.paths) < 0) {
perror("read_cache_preload");
return -1;
}
result = run_diff_files(revs, options);
return diff_result_code(&revs->diffopt, result);
}
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;
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)
*
* N=0, M=0, P=2:
* compare two filesystem entities (aka --no-index).
*
* Other cases are errors.
*/
prefix = setup_git_directory_gently(&nongit);
gitmodules_config();
git_config(git_diff_ui_config, NULL);
if (diff_use_color_default == -1)
diff_use_color_default = git_use_color_default;
init_revisions(&rev, prefix);
/* If this is a no-index diff, just run it and exit there. */
diff_no_index(&rev, argc, argv, nongit, prefix);
/* Otherwise, we are doing the usual "git" diff */
rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
/* Default to let external and textconv be used */
DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
if (nongit)
die("Not a git repository");
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");
}
DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
/*
* 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 (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS) &&
check_pager_config("diff") != 0)
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") ||
!strcmp(arg, "--staged")) {
add_head_to_pending(&rev);
if (!rev.pending.nr) {
struct tree *tree;
tree = lookup_tree((const unsigned char*)EMPTY_TREE_SHA1_BIN);
add_pending_object(&rev, &tree->object, "HEAD");
}
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 = builtin_diff_files(&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 (ent[0].item->flags & UNINTERESTING) {
/*
* diff A...B where there is at least one merge base
* between A and B. We have ent[0] == merge-base,
* ent[ents-2] == A, and ent[ents-1] == B. Show diff
* between the base and B. Note that we pick one
* merge base at random if there are more than one.
*/
ent[1] = ent[ents-1];
result = builtin_diff_tree(&rev, argc, argv, ent);
} else
result = builtin_diff_combined(&rev, argc, argv,
ent, ents);
result = diff_result_code(&rev.diffopt, result);
if (1 < rev.diffopt.skip_stat_unmatch)
refresh_index_quietly();
return result;
}