git/diff-lib.c
Eric W. Biederman efed687edc tree-walk: init_tree_desc take an oid to get the hash algorithm
To make it possible for git ls-tree to display the tree encoded
in the hash algorithm of the oid specified to git ls-tree, update
init_tree_desc to take as a parameter the oid of the tree object.

Update all callers of init_tree_desc and init_tree_desc_gently
to pass the oid of the tree object.

Use the oid of the tree object to discover the hash algorithm
of the oid and store that hash algorithm in struct tree_desc.

Use the hash algorithm in decode_tree_entry and
update_tree_entry_internal to handle reading a tree object encoded in
a hash algorithm that differs from the repositories hash algorithm.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02 14:57:40 -07:00

714 lines
19 KiB
C

/*
* Copyright (C) 2005 Junio C Hamano
*/
#include "git-compat-util.h"
#include "quote.h"
#include "commit.h"
#include "diff.h"
#include "diffcore.h"
#include "gettext.h"
#include "hash.h"
#include "hex.h"
#include "object-name.h"
#include "read-cache.h"
#include "revision.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "refs.h"
#include "repository.h"
#include "submodule.h"
#include "symlinks.h"
#include "trace.h"
#include "dir.h"
#include "fsmonitor.h"
#include "commit-reach.h"
/*
* diff-files
*/
/*
* Has the work tree entity been removed?
*
* Return 1 if it was removed from the work tree, 0 if an entity to be
* compared with the cache entry ce still exists (the latter includes
* the case where a directory that is not a submodule repository
* exists for ce that is a submodule -- it is a submodule that is not
* checked out). Return negative for an error.
*/
static int check_removed(const struct index_state *istate, const struct cache_entry *ce, struct stat *st)
{
assert(is_fsmonitor_refreshed(istate));
if (!(ce->ce_flags & CE_FSMONITOR_VALID) && lstat(ce->name, st) < 0) {
if (!is_missing_file_error(errno))
return -1;
return 1;
}
if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
return 1;
if (S_ISDIR(st->st_mode)) {
struct object_id sub;
/*
* If ce is already a gitlink, we can have a plain
* directory (i.e. the submodule is not checked out),
* or a checked out submodule. Either case this is not
* a case where something was removed from the work tree,
* so we will return 0.
*
* Otherwise, if the directory is not a submodule
* repository, that means ce which was a blob turned into
* a directory --- the blob was removed!
*/
if (!S_ISGITLINK(ce->ce_mode) &&
resolve_gitlink_ref(ce->name, "HEAD", &sub))
return 1;
}
return 0;
}
/*
* Has a file changed or has a submodule new commits or a dirty work tree?
*
* Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
* option is set, the caller does not only want to know if a submodule is
* modified at all but wants to know all the conditions that are met (new
* commits, untracked content and/or modified content).
*/
static int match_stat_with_submodule(struct diff_options *diffopt,
const struct cache_entry *ce,
struct stat *st, unsigned ce_option,
unsigned *dirty_submodule)
{
int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
if (S_ISGITLINK(ce->ce_mode)) {
struct diff_flags orig_flags = diffopt->flags;
if (!diffopt->flags.override_submodule_config)
set_diffopt_flags_from_submodule_config(diffopt, ce->name);
if (diffopt->flags.ignore_submodules)
changed = 0;
else if (!diffopt->flags.ignore_dirty_submodules &&
(!changed || diffopt->flags.dirty_submodules))
*dirty_submodule = is_submodule_modified(ce->name,
diffopt->flags.ignore_untracked_in_submodules);
diffopt->flags = orig_flags;
}
return changed;
}
int run_diff_files(struct rev_info *revs, unsigned int option)
{
int entries, i;
int diff_unmerged_stage = revs->max_count;
unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
? CE_MATCH_RACY_IS_DIRTY : 0);
uint64_t start = getnanotime();
struct index_state *istate = revs->diffopt.repo->index;
diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
refresh_fsmonitor(istate);
if (diff_unmerged_stage < 0)
diff_unmerged_stage = 2;
entries = istate->cache_nr;
for (i = 0; i < entries; i++) {
unsigned int oldmode, newmode;
struct cache_entry *ce = istate->cache[i];
int changed;
unsigned dirty_submodule = 0;
const struct object_id *old_oid, *new_oid;
if (diff_can_quit_early(&revs->diffopt))
break;
if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
continue;
if (revs->diffopt.prefix &&
strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
continue;
if (ce_stage(ce)) {
struct combine_diff_path *dpath;
struct diff_filepair *pair;
unsigned int wt_mode = 0;
int num_compare_stages = 0;
size_t path_len;
struct stat st;
path_len = ce_namelen(ce);
dpath = xmalloc(combine_diff_path_size(5, path_len));
dpath->path = (char *) &(dpath->parent[5]);
dpath->next = NULL;
memcpy(dpath->path, ce->name, path_len);
dpath->path[path_len] = '\0';
oidclr(&dpath->oid);
memset(&(dpath->parent[0]), 0,
sizeof(struct combine_diff_parent)*5);
changed = check_removed(istate, ce, &st);
if (!changed)
wt_mode = ce_mode_from_stat(ce, st.st_mode);
else {
if (changed < 0) {
perror(ce->name);
continue;
}
wt_mode = 0;
}
dpath->mode = wt_mode;
while (i < entries) {
struct cache_entry *nce = istate->cache[i];
int stage;
if (strcmp(ce->name, nce->name))
break;
/* Stage #2 (ours) is the first parent,
* stage #3 (theirs) is the second.
*/
stage = ce_stage(nce);
if (2 <= stage) {
int mode = nce->ce_mode;
num_compare_stages++;
oidcpy(&dpath->parent[stage - 2].oid,
&nce->oid);
dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
dpath->parent[stage-2].status =
DIFF_STATUS_MODIFIED;
}
/* diff against the proper unmerged stage */
if (stage == diff_unmerged_stage)
ce = nce;
i++;
}
/*
* Compensate for loop update
*/
i--;
if (revs->combine_merges && num_compare_stages == 2) {
show_combined_diff(dpath, 2, revs);
free(dpath);
continue;
}
FREE_AND_NULL(dpath);
/*
* Show the diff for the 'ce' if we found the one
* from the desired stage.
*/
pair = diff_unmerge(&revs->diffopt, ce->name);
if (wt_mode)
pair->two->mode = wt_mode;
if (ce_stage(ce) != diff_unmerged_stage)
continue;
}
if (ce_uptodate(ce) || ce_skip_worktree(ce))
continue;
/*
* When CE_VALID is set (via "update-index --assume-unchanged"
* or via adding paths while core.ignorestat is set to true),
* the user has promised that the working tree file for that
* path will not be modified. When CE_FSMONITOR_VALID is true,
* the fsmonitor knows that the path hasn't been modified since
* we refreshed the cached stat information. In either case,
* we do not have to stat to see if the path has been removed
* or modified.
*/
if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
changed = 0;
newmode = ce->ce_mode;
} else {
struct stat st;
changed = check_removed(istate, ce, &st);
if (changed) {
if (changed < 0) {
perror(ce->name);
continue;
}
diff_addremove(&revs->diffopt, '-', ce->ce_mode,
&ce->oid,
!is_null_oid(&ce->oid),
ce->name, 0);
continue;
} else if (revs->diffopt.ita_invisible_in_index &&
ce_intent_to_add(ce)) {
newmode = ce_mode_from_stat(ce, st.st_mode);
diff_addremove(&revs->diffopt, '+', newmode,
null_oid(), 0, ce->name, 0);
continue;
}
changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
ce_option, &dirty_submodule);
newmode = ce_mode_from_stat(ce, st.st_mode);
}
if (!changed && !dirty_submodule) {
ce_mark_uptodate(ce);
mark_fsmonitor_valid(istate, ce);
if (!revs->diffopt.flags.find_copies_harder)
continue;
}
oldmode = ce->ce_mode;
old_oid = &ce->oid;
new_oid = changed ? null_oid() : &ce->oid;
diff_change(&revs->diffopt, oldmode, newmode,
old_oid, new_oid,
!is_null_oid(old_oid),
!is_null_oid(new_oid),
ce->name, 0, dirty_submodule);
}
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
trace_performance_since(start, "diff-files");
return 0;
}
/*
* diff-index
*/
/* A file entry went away or appeared */
static void diff_index_show_file(struct rev_info *revs,
const char *prefix,
const struct cache_entry *ce,
const struct object_id *oid, int oid_valid,
unsigned int mode,
unsigned dirty_submodule)
{
diff_addremove(&revs->diffopt, prefix[0], mode,
oid, oid_valid, ce->name, dirty_submodule);
}
static int get_stat_data(const struct index_state *istate,
const struct cache_entry *ce,
const struct object_id **oidp,
unsigned int *modep,
int cached, int match_missing,
unsigned *dirty_submodule, struct diff_options *diffopt)
{
const struct object_id *oid = &ce->oid;
unsigned int mode = ce->ce_mode;
if (!cached && !ce_uptodate(ce)) {
int changed;
struct stat st;
changed = check_removed(istate, ce, &st);
if (changed < 0)
return -1;
else if (changed) {
if (match_missing) {
*oidp = oid;
*modep = mode;
return 0;
}
return -1;
}
changed = match_stat_with_submodule(diffopt, ce, &st,
0, dirty_submodule);
if (changed) {
mode = ce_mode_from_stat(ce, st.st_mode);
oid = null_oid();
}
}
*oidp = oid;
*modep = mode;
return 0;
}
static void show_new_file(struct rev_info *revs,
const struct cache_entry *new_file,
int cached, int match_missing)
{
const struct object_id *oid;
unsigned int mode;
unsigned dirty_submodule = 0;
struct index_state *istate = revs->diffopt.repo->index;
if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
return;
}
/*
* New file in the index: it might actually be different in
* the working tree.
*/
if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
&dirty_submodule, &revs->diffopt) < 0)
return;
diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
}
static int show_modified(struct rev_info *revs,
const struct cache_entry *old_entry,
const struct cache_entry *new_entry,
int report_missing,
int cached, int match_missing)
{
unsigned int mode, oldmode;
const struct object_id *oid;
unsigned dirty_submodule = 0;
struct index_state *istate = revs->diffopt.repo->index;
assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
S_ISSPARSEDIR(new_entry->ce_mode));
/*
* If both are sparse directory entries, then expand the
* modifications to the file level. If only one was a sparse
* directory, then they appear as an add and delete instead of
* a modification.
*/
if (S_ISSPARSEDIR(new_entry->ce_mode)) {
diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
return 0;
}
if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
&dirty_submodule, &revs->diffopt) < 0) {
if (report_missing)
diff_index_show_file(revs, "-", old_entry,
&old_entry->oid, 1, old_entry->ce_mode,
0);
return -1;
}
if (revs->combine_merges && !cached &&
(!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
struct combine_diff_path *p;
int pathlen = ce_namelen(new_entry);
p = xmalloc(combine_diff_path_size(2, pathlen));
p->path = (char *) &p->parent[2];
p->next = NULL;
memcpy(p->path, new_entry->name, pathlen);
p->path[pathlen] = 0;
p->mode = mode;
oidclr(&p->oid);
memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
p->parent[0].status = DIFF_STATUS_MODIFIED;
p->parent[0].mode = new_entry->ce_mode;
oidcpy(&p->parent[0].oid, &new_entry->oid);
p->parent[1].status = DIFF_STATUS_MODIFIED;
p->parent[1].mode = old_entry->ce_mode;
oidcpy(&p->parent[1].oid, &old_entry->oid);
show_combined_diff(p, 2, revs);
free(p);
return 0;
}
oldmode = old_entry->ce_mode;
if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
!revs->diffopt.flags.find_copies_harder)
return 0;
diff_change(&revs->diffopt, oldmode, mode,
&old_entry->oid, oid, 1, !is_null_oid(oid),
old_entry->name, 0, dirty_submodule);
return 0;
}
/*
* This gets a mix of an existing index and a tree, one pathname entry
* at a time. The index entry may be a single stage-0 one, but it could
* also be multiple unmerged entries (in which case idx_pos/idx_nr will
* give you the position and number of entries in the index).
*/
static void do_oneway_diff(struct unpack_trees_options *o,
const struct cache_entry *idx,
const struct cache_entry *tree)
{
struct rev_info *revs = o->unpack_data;
int match_missing, cached;
/*
* i-t-a entries do not actually exist in the index (if we're
* looking at its content)
*/
if (o->index_only &&
revs->diffopt.ita_invisible_in_index &&
idx && ce_intent_to_add(idx)) {
idx = NULL;
if (!tree)
return; /* nothing to diff.. */
}
/* if the entry is not checked out, don't examine work tree */
cached = o->index_only ||
(idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
match_missing = revs->match_missing;
if (cached && idx && ce_stage(idx)) {
struct diff_filepair *pair;
pair = diff_unmerge(&revs->diffopt, idx->name);
if (tree)
fill_filespec(pair->one, &tree->oid, 1,
tree->ce_mode);
return;
}
/*
* Something added to the tree?
*/
if (!tree) {
show_new_file(revs, idx, cached, match_missing);
return;
}
/*
* Something removed from the tree?
*/
if (!idx) {
if (S_ISSPARSEDIR(tree->ce_mode)) {
diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
return;
}
diff_index_show_file(revs, "-", tree, &tree->oid, 1,
tree->ce_mode, 0);
return;
}
/* Show difference between old and new */
show_modified(revs, tree, idx, 1, cached, match_missing);
}
/*
* The unpack_trees() interface is designed for merging, so
* the different source entries are designed primarily for
* the source trees, with the old index being really mainly
* used for being replaced by the result.
*
* For diffing, the index is more important, and we only have a
* single tree.
*
* We're supposed to advance o->pos to skip what we have already processed.
*
* This wrapper makes it all more readable, and takes care of all
* the fairly complex unpack_trees() semantic requirements, including
* the skipping, the path matching, the type conflict cases etc.
*/
static int oneway_diff(const struct cache_entry * const *src,
struct unpack_trees_options *o)
{
const struct cache_entry *idx = src[0];
const struct cache_entry *tree = src[1];
struct rev_info *revs = o->unpack_data;
/*
* Unpack-trees generates a DF/conflict entry if
* there was a directory in the index and a tree
* in the tree. From a diff standpoint, that's a
* delete of the tree and a create of the file.
*/
if (tree == o->df_conflict_entry)
tree = NULL;
if (ce_path_match(revs->diffopt.repo->index,
idx ? idx : tree,
&revs->prune_data, NULL)) {
do_oneway_diff(o, idx, tree);
if (diff_can_quit_early(&revs->diffopt)) {
o->exiting_early = 1;
return -1;
}
}
return 0;
}
static int diff_cache(struct rev_info *revs,
const struct object_id *tree_oid,
const char *tree_name,
int cached)
{
struct tree *tree;
struct tree_desc t;
struct unpack_trees_options opts;
tree = parse_tree_indirect(tree_oid);
if (!tree)
return error("bad tree object %s",
tree_name ? tree_name : oid_to_hex(tree_oid));
memset(&opts, 0, sizeof(opts));
opts.head_idx = 1;
opts.index_only = cached;
opts.diff_index_cached = (cached &&
!revs->diffopt.flags.find_copies_harder);
opts.merge = 1;
opts.fn = oneway_diff;
opts.unpack_data = revs;
opts.src_index = revs->diffopt.repo->index;
opts.dst_index = NULL;
opts.pathspec = &revs->diffopt.pathspec;
opts.pathspec->recursive = 1;
init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
return unpack_trees(1, &t, &opts);
}
void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
{
int i;
struct commit *mb_child[2] = {0};
struct commit_list *merge_bases;
for (i = 0; i < revs->pending.nr; i++) {
struct object *obj = revs->pending.objects[i].item;
if (obj->flags)
die(_("--merge-base does not work with ranges"));
if (obj->type != OBJ_COMMIT)
die(_("--merge-base only works with commits"));
}
/*
* This check must go after the for loop above because A...B
* ranges produce three pending commits, resulting in a
* misleading error message.
*/
if (revs->pending.nr < 1 || revs->pending.nr > 2)
BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
for (i = 0; i < revs->pending.nr; i++)
mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
if (revs->pending.nr == 1) {
struct object_id oid;
if (repo_get_oid(the_repository, "HEAD", &oid))
die(_("unable to get HEAD"));
mb_child[1] = lookup_commit_reference(the_repository, &oid);
}
merge_bases = repo_get_merge_bases(the_repository, mb_child[0], mb_child[1]);
if (!merge_bases)
die(_("no merge base found"));
if (merge_bases->next)
die(_("multiple merge bases found"));
oidcpy(mb, &merge_bases->item->object.oid);
free_commit_list(merge_bases);
}
int run_diff_index(struct rev_info *revs, unsigned int option)
{
struct object_array_entry *ent;
int cached = !!(option & DIFF_INDEX_CACHED);
int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
struct object_id oid;
const char *name;
char merge_base_hex[GIT_MAX_HEXSZ + 1];
struct index_state *istate = revs->diffopt.repo->index;
if (revs->pending.nr != 1)
BUG("run_diff_index must be passed exactly one tree");
trace_performance_enter();
ent = revs->pending.objects;
refresh_fsmonitor(istate);
if (merge_base) {
diff_get_merge_base(revs, &oid);
name = oid_to_hex_r(merge_base_hex, &oid);
} else {
oidcpy(&oid, &ent->item->oid);
name = ent->name;
}
if (diff_cache(revs, &oid, name, cached))
exit(128);
diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
diffcore_fix_diff_index();
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
trace_performance_leave("diff-index");
return 0;
}
int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
{
struct rev_info revs;
repo_init_revisions(opt->repo, &revs, NULL);
copy_pathspec(&revs.prune_data, &opt->pathspec);
diff_setup_done(&revs.diffopt);
revs.diffopt = *opt;
if (diff_cache(&revs, tree_oid, NULL, 1))
exit(128);
release_revisions(&revs);
return 0;
}
int index_differs_from(struct repository *r,
const char *def, const struct diff_flags *flags,
int ita_invisible_in_index)
{
struct rev_info rev;
struct setup_revision_opt opt;
unsigned has_changes;
repo_init_revisions(r, &rev, NULL);
memset(&opt, 0, sizeof(opt));
opt.def = def;
setup_revisions(0, NULL, &rev, &opt);
rev.diffopt.flags.quick = 1;
rev.diffopt.flags.exit_with_status = 1;
if (flags) {
diff_flags_or(&rev.diffopt.flags, flags);
/*
* Now that flags are merged, honor override_submodule_config
* and ignore_submodules from passed flags.
*/
if (flags->override_submodule_config)
rev.diffopt.flags.ignore_submodules = flags->ignore_submodules;
}
rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
run_diff_index(&rev, 1);
has_changes = rev.diffopt.flags.has_changes;
release_revisions(&rev);
return (has_changes != 0);
}
static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
{
return data;
}
void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
int indent, struct diff_options *diffopt)
{
struct diff_options opts;
struct strbuf prefix = STRBUF_INIT;
memcpy(&opts, diffopt, sizeof(opts));
opts.output_format = DIFF_FORMAT_PATCH;
opts.output_prefix = idiff_prefix_cb;
strbuf_addchars(&prefix, ' ', indent);
opts.output_prefix_data = &prefix;
diff_setup_done(&opts);
diff_tree_oid(oid1, oid2, "", &opts);
diffcore_std(&opts);
diff_flush(&opts);
strbuf_release(&prefix);
}