diff.c
/*
* Builtin "git diff"
*
* Copyright (c) 2006 Junio C Hamano
*/
#define USE_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "config.h"
#include "ewah/ewok.h"
#include "lockfile.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"
#include "oid-array.h"
#define DIFF_NO_INDEX_EXPLICIT 1
#define DIFF_NO_INDEX_IMPLICIT 2
static const char builtin_diff_usage[] =
"git diff [<options>] [<commit>] [--] [<path>...]\n"
" or: git diff [<options>] --cached [<commit>] [--] [<path>...]\n"
" or: git diff [<options>] <commit> [<commit>...] <commit> [--] [<path>...]\n"
" or: git diff [<options>] <commit>...<commit>] [--] [<path>...]\n"
" or: git diff [<options>] <blob> <blob>]\n"
" or: git diff [<options>] --no-index [--] <path> <path>]\n"
COMMON_DIFF_OPTIONS_HELP;
static const char *blob_path(struct object_array_entry *entry)
{
return entry->path ? entry->path : entry->name;
}
static void stuff_change(struct diff_options *opt,
unsigned old_mode, unsigned new_mode,
const struct object_id *old_oid,
const struct object_id *new_oid,
int old_oid_valid,
int new_oid_valid,
const char *old_path,
const char *new_path)
{
struct diff_filespec *one, *two;
if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
oideq(old_oid, new_oid) && (old_mode == new_mode))
return;
if (opt->flags.reverse_diff) {
SWAP(old_mode, new_mode);
SWAP(old_oid, new_oid);
SWAP(old_path, new_path);
}
if (opt->prefix &&
(strncmp(old_path, opt->prefix, opt->prefix_length) ||
strncmp(new_path, opt->prefix, opt->prefix_length)))
return;
one = alloc_filespec(old_path);
two = alloc_filespec(new_path);
fill_filespec(one, old_oid, old_oid_valid, old_mode);
fill_filespec(two, new_oid, new_oid_valid, 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 object_array_entry **blob)
{
/* Blob vs file in the working tree*/
struct stat st;
const char *path;
if (argc > 1)
usage(builtin_diff_usage);
GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
path = revs->prune_data.items[0].match;
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]->item->oid, &null_oid,
1, 0,
blob[0]->path ? blob[0]->path : 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 object_array_entry **blob)
{
const 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]->item->oid, &blob[1]->item->oid,
1, 1,
blob_path(blob[0]), blob_path(blob[1]));
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--;
}
/*
* 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 (!cached) {
setup_work_tree();
if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
perror("read_cache_preload");
return -1;
}
} else 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 *ent0,
struct object_array_entry *ent1)
{
const struct object_id *(oid[2]);
int swap = 0;
if (argc > 1)
usage(builtin_diff_usage);
/*
* We saw two trees, ent0 and ent1. If ent1 is uninteresting,
* swap them.
*/
if (ent1->item->flags & UNINTERESTING)
swap = 1;
oid[swap] = &ent0->item->oid;
oid[1 - swap] = &ent1->item->oid;
diff_tree_oid(oid[0], oid[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)
{
struct oid_array parents = OID_ARRAY_INIT;
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;
for (i = 1; i < ents; i++)
oid_array_append(&parents, &ent[i].item->oid);
diff_tree_combined(&ent[0].item->oid, &parents,
revs->dense_combined_merges, revs);
oid_array_clear(&parents);
return 0;
}
static void refresh_index_quietly(void)
{
struct lock_file lock_file = LOCK_INIT;
int fd;
fd = hold_locked_index(&lock_file, 0);
if (fd < 0)
return;
discard_cache();
read_cache();
refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
repo_update_index_if_able(the_repository, &lock_file);
}
static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
{
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.pathspec) < 0) {
perror("read_cache_preload");
return -1;
}
return run_diff_files(revs, options);
}
struct symdiff {
struct bitmap *skip;
int warn;
const char *base, *left, *right;
};
/*
* Check for symmetric-difference arguments, and if present, arrange
* everything we need to know to handle them correctly. As a bonus,
* weed out all bogus range-based revision specifications, e.g.,
* "git diff A..B C..D" or "git diff A..B C" get rejected.
*
* For an actual symmetric diff, *symdiff is set this way:
*
* - its skip is non-NULL and marks *all* rev->pending.objects[i]
* indices that the caller should ignore (extra merge bases, of
* which there might be many, and A in A...B). Note that the
* chosen merge base and right side are NOT marked.
* - warn is set if there are multiple merge bases.
* - base, left, and right point to the names to use in a
* warning about multiple merge bases.
*
* If there is no symmetric diff argument, sym->skip is NULL and
* sym->warn is cleared. The remaining fields are not set.
*/
static void symdiff_prepare(struct rev_info *rev, struct symdiff *sym)
{
int i, is_symdiff = 0, basecount = 0, othercount = 0;
int lpos = -1, rpos = -1, basepos = -1;
struct bitmap *map = NULL;
/*
* Use the whence fields to find merge bases and left and
* right parts of symmetric difference, so that we do not
* depend on the order that revisions are parsed. If there
* are any revs that aren't from these sources, we have a
* "git diff C A...B" or "git diff A...B C" case. Or we
* could even get "git diff A...B C...E", for instance.
*
* If we don't have just one merge base, we pick one
* at random.
*
* NB: REV_CMD_LEFT, REV_CMD_RIGHT are also used for A..B,
* so we must check for SYMMETRIC_LEFT too. The two arrays
* rev->pending.objects and rev->cmdline.rev are parallel.
*/
for (i = 0; i < rev->cmdline.nr; i++) {
struct object *obj = rev->pending.objects[i].item;
switch (rev->cmdline.rev[i].whence) {
case REV_CMD_MERGE_BASE:
if (basepos < 0)
basepos = i;
basecount++;
break; /* do mark all bases */
case REV_CMD_LEFT:
if (lpos >= 0)
usage(builtin_diff_usage);
lpos = i;
if (obj->flags & SYMMETRIC_LEFT) {
is_symdiff = 1;
break; /* do mark A */
}
continue;
case REV_CMD_RIGHT:
if (rpos >= 0)
usage(builtin_diff_usage);
rpos = i;
continue; /* don't mark B */
case REV_CMD_PARENTS_ONLY:
case REV_CMD_REF:
case REV_CMD_REV:
othercount++;
continue;
}
if (map == NULL)
map = bitmap_new();
bitmap_set(map, i);
}
/*
* Forbid any additional revs for both A...B and A..B.
*/
if (lpos >= 0 && othercount > 0)
usage(builtin_diff_usage);
if (!is_symdiff) {
bitmap_free(map);
sym->warn = 0;
sym->skip = NULL;
return;
}
sym->left = rev->pending.objects[lpos].name;
sym->right = rev->pending.objects[rpos].name;
if (basecount == 0)
die(_("%s...%s: no merge base"), sym->left, sym->right);
sym->base = rev->pending.objects[basepos].name;
bitmap_unset(map, basepos); /* unmark the base we want */
sym->warn = basecount > 1;
sym->skip = map;
}
int cmd_diff(int argc, const char **argv, const char *prefix)
{
int i;
struct rev_info rev;
struct object_array ent = OBJECT_ARRAY_INIT;
int blobs = 0, paths = 0;
struct object_array_entry *blob[2];
int nongit = 0, no_index = 0;
int result = 0;
struct symdiff sdiff;
/*
* We could get N tree-ish in the rev.pending_objects list.
* Also there could be M blobs there, and P pathspecs. --cached may
* also be present.
*
* N=0, M=0:
* cache vs files (diff-files)
*
* N=0, M=0, --cached:
* HEAD vs cache (diff-index --cached)
*
* 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 files (diff-index)
*
* N=1, M=0, --cached:
* 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.
*/
/* Were we asked to do --no-index explicitly? */
for (i = 1; i < argc; i++) {
if (!strcmp(argv[i], "--")) {
i++;
break;
}
if (!strcmp(argv[i], "--no-index"))
no_index = DIFF_NO_INDEX_EXPLICIT;
if (argv[i][0] != '-')
break;
}
prefix = setup_git_directory_gently(&nongit);
if (!no_index) {
/*
* Treat git diff with at least one path outside of the
* repo the same as if the command would have been executed
* outside of a git repository. In this case it behaves
* the same way as "git diff --no-index <a> <b>", which acts
* as a colourful "diff" replacement.
*/
if (nongit || ((argc == i + 2) &&
(!path_inside_repo(prefix, argv[i]) ||
!path_inside_repo(prefix, argv[i + 1]))))
no_index = DIFF_NO_INDEX_IMPLICIT;
}
init_diff_ui_defaults();
git_config(git_diff_ui_config, NULL);
precompose_argv(argc, argv);
repo_init_revisions(the_repository, &rev, prefix);
/* Set up defaults that will apply to both no-index and regular diffs. */
rev.diffopt.stat_width = -1;
rev.diffopt.stat_graph_width = -1;
rev.diffopt.flags.allow_external = 1;
rev.diffopt.flags.allow_textconv = 1;
/* If this is a no-index diff, just run it and exit there. */
if (no_index)
exit(diff_no_index(&rev, no_index == DIFF_NO_INDEX_IMPLICIT,
argc, argv));
/*
* Otherwise, we are doing the usual "git" diff; set up any
* further defaults that apply to regular diffs.
*/
rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
/*
* Default to intent-to-add entries invisible in the
* index. This makes them show up as new files in diff-files
* and not at all in diff-cached.
*/
rev.diffopt.ita_invisible_in_index = 1;
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;
diff_setup_done(&rev.diffopt);
}
rev.diffopt.flags.recursive = 1;
setup_diff_pager(&rev.diffopt);
/*
* 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(the_repository,
the_repository->hash_algo->empty_tree);
add_pending_object(&rev, &tree->object, "HEAD");
}
break;
}
}
}
symdiff_prepare(&rev, &sdiff);
for (i = 0; i < rev.pending.nr; i++) {
struct object_array_entry *entry = &rev.pending.objects[i];
struct object *obj = entry->item;
const char *name = entry->name;
int flags = (obj->flags & UNINTERESTING);
if (!obj->parsed)
obj = parse_object(the_repository, &obj->oid);
obj = deref_tag(the_repository, obj, NULL, 0);
if (!obj)
die(_("invalid object '%s' given."), name);
if (obj->type == OBJ_COMMIT)
obj = &get_commit_tree(((struct commit *)obj))->object;
if (obj->type == OBJ_TREE) {
if (sdiff.skip && bitmap_get(sdiff.skip, i))
continue;
obj->flags |= flags;
add_object_array(obj, name, &ent);
} else if (obj->type == OBJ_BLOB) {
if (2 <= blobs)
die(_("more than two blobs given: '%s'"), name);
blob[blobs] = entry;
blobs++;
} else {
die(_("unhandled object '%s' given."), name);
}
}
if (rev.prune_data.nr)
paths += rev.prune_data.nr;
/*
* Now, do the arguments look reasonable?
*/
if (!ent.nr) {
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);
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 (ent.nr == 1)
result = builtin_diff_index(&rev, argc, argv);
else if (ent.nr == 2) {
if (sdiff.warn)
warning(_("%s...%s: multiple merge bases, using %s"),
sdiff.left, sdiff.right, sdiff.base);
result = builtin_diff_tree(&rev, argc, argv,
&ent.objects[0], &ent.objects[1]);
} else
result = builtin_diff_combined(&rev, argc, argv,
ent.objects, ent.nr);
result = diff_result_code(&rev.diffopt, result);
if (1 < rev.diffopt.skip_stat_unmatch)
refresh_index_quietly();
UNLEAK(rev);
UNLEAK(ent);
UNLEAK(blob);
return result;
}