git/worktree.c
Jeff King e4da43b1f0 prefix_filename: return newly allocated string
The prefix_filename() function returns a pointer to static
storage, which makes it easy to use dangerously. We already
fixed one buggy caller in hash-object recently, and the
calls in apply.c are suspicious (I didn't dig in enough to
confirm that there is a bug, but we call the function once
in apply_all_patches() and then again indirectly from
parse_chunk()).

Let's make it harder to get wrong by allocating the return
value. For simplicity, we'll do this even when the prefix is
empty (and we could just return the original file pointer).
That will cause us to allocate sometimes when we wouldn't
otherwise need to, but this function isn't called in
performance critical code-paths (and it already _might_
allocate on any given call, so a caller that cares about
performance is questionable anyway).

The downside is that the callers need to remember to free()
the result to avoid leaking. Most of them already used
xstrdup() on the result, so we know they are OK. The
remainder have been converted to use free() as appropriate.

I considered retaining a prefix_filename_unsafe() for cases
where we know the static lifetime is OK (and handling the
cleanup is awkward). This is only a handful of cases,
though, and it's not worth the mental energy in worrying
about whether the "unsafe" variant is OK to use in any
situation.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-21 11:18:41 -07:00

436 lines
10 KiB
C

#include "cache.h"
#include "refs.h"
#include "strbuf.h"
#include "worktree.h"
#include "dir.h"
#include "wt-status.h"
void free_worktrees(struct worktree **worktrees)
{
int i = 0;
for (i = 0; worktrees[i]; i++) {
free(worktrees[i]->path);
free(worktrees[i]->id);
free(worktrees[i]->head_ref);
free(worktrees[i]->lock_reason);
free(worktrees[i]);
}
free (worktrees);
}
/*
* read 'path_to_ref' into 'ref'. Also if is_detached is not NULL,
* set is_detached to 1 (0) if the ref is detached (is not detached).
*
* $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
* for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
* git_path). Parse the ref ourselves.
*
* return -1 if the ref is not a proper ref, 0 otherwise (success)
*/
static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
{
if (is_detached)
*is_detached = 0;
if (!strbuf_readlink(ref, path_to_ref, 0)) {
/* HEAD is symbolic link */
if (!starts_with(ref->buf, "refs/") ||
check_refname_format(ref->buf, 0))
return -1;
} else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
/* textual symref or detached */
if (!starts_with(ref->buf, "ref:")) {
if (is_detached)
*is_detached = 1;
} else {
strbuf_remove(ref, 0, strlen("ref:"));
strbuf_trim(ref);
if (check_refname_format(ref->buf, 0))
return -1;
}
} else
return -1;
return 0;
}
/**
* Add the head_sha1 and head_ref (if not detached) to the given worktree
*/
static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
{
if (head_ref->len) {
if (worktree->is_detached) {
get_sha1_hex(head_ref->buf, worktree->head_sha1);
} else {
resolve_ref_unsafe(head_ref->buf, 0, worktree->head_sha1, NULL);
worktree->head_ref = strbuf_detach(head_ref, NULL);
}
}
}
/**
* get the main worktree
*/
static struct worktree *get_main_worktree(void)
{
struct worktree *worktree = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf worktree_path = STRBUF_INIT;
struct strbuf head_ref = STRBUF_INIT;
int is_bare = 0;
int is_detached = 0;
strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
if (is_bare)
strbuf_strip_suffix(&worktree_path, "/.");
strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
worktree->is_bare = is_bare;
worktree->is_detached = is_detached;
if (!parse_ref(path.buf, &head_ref, &is_detached))
add_head_info(&head_ref, worktree);
strbuf_release(&path);
strbuf_release(&worktree_path);
strbuf_release(&head_ref);
return worktree;
}
static struct worktree *get_linked_worktree(const char *id)
{
struct worktree *worktree = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf worktree_path = STRBUF_INIT;
struct strbuf head_ref = STRBUF_INIT;
int is_detached = 0;
if (!id)
die("Missing linked worktree name");
strbuf_git_common_path(&path, "worktrees/%s/gitdir", id);
if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
/* invalid gitdir file */
goto done;
strbuf_rtrim(&worktree_path);
if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
strbuf_reset(&worktree_path);
strbuf_add_absolute_path(&worktree_path, ".");
strbuf_strip_suffix(&worktree_path, "/.");
}
strbuf_reset(&path);
strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
goto done;
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
worktree->id = xstrdup(id);
worktree->is_detached = is_detached;
add_head_info(&head_ref, worktree);
done:
strbuf_release(&path);
strbuf_release(&worktree_path);
strbuf_release(&head_ref);
return worktree;
}
static void mark_current_worktree(struct worktree **worktrees)
{
char *git_dir = absolute_pathdup(get_git_dir());
int i;
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
const char *wt_git_dir = get_worktree_git_dir(wt);
if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
wt->is_current = 1;
break;
}
}
free(git_dir);
}
static int compare_worktree(const void *a_, const void *b_)
{
const struct worktree *const *a = a_;
const struct worktree *const *b = b_;
return fspathcmp((*a)->path, (*b)->path);
}
struct worktree **get_worktrees(unsigned flags)
{
struct worktree **list = NULL;
struct strbuf path = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int counter = 0, alloc = 2;
ALLOC_ARRAY(list, alloc);
list[counter++] = get_main_worktree();
strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
dir = opendir(path.buf);
strbuf_release(&path);
if (dir) {
while ((d = readdir(dir)) != NULL) {
struct worktree *linked = NULL;
if (is_dot_or_dotdot(d->d_name))
continue;
if ((linked = get_linked_worktree(d->d_name))) {
ALLOC_GROW(list, counter + 1, alloc);
list[counter++] = linked;
}
}
closedir(dir);
}
ALLOC_GROW(list, counter + 1, alloc);
list[counter] = NULL;
if (flags & GWT_SORT_LINKED)
/*
* don't sort the first item (main worktree), which will
* always be the first
*/
QSORT(list + 1, counter - 1, compare_worktree);
mark_current_worktree(list);
return list;
}
const char *get_worktree_git_dir(const struct worktree *wt)
{
if (!wt)
return get_git_dir();
else if (!wt->id)
return get_git_common_dir();
else
return git_common_path("worktrees/%s", wt->id);
}
static struct worktree *find_worktree_by_suffix(struct worktree **list,
const char *suffix)
{
struct worktree *found = NULL;
int nr_found = 0, suffixlen;
suffixlen = strlen(suffix);
if (!suffixlen)
return NULL;
for (; *list && nr_found < 2; list++) {
const char *path = (*list)->path;
int pathlen = strlen(path);
int start = pathlen - suffixlen;
/* suffix must start at directory boundary */
if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
!fspathcmp(suffix, path + start)) {
found = *list;
nr_found++;
}
}
return nr_found == 1 ? found : NULL;
}
struct worktree *find_worktree(struct worktree **list,
const char *prefix,
const char *arg)
{
struct worktree *wt;
char *path;
char *to_free = NULL;
if ((wt = find_worktree_by_suffix(list, arg)))
return wt;
if (prefix)
arg = to_free = prefix_filename(prefix, arg);
path = real_pathdup(arg, 1);
for (; *list; list++)
if (!fspathcmp(path, real_path((*list)->path)))
break;
free(path);
free(to_free);
return *list;
}
int is_main_worktree(const struct worktree *wt)
{
return !wt->id;
}
const char *is_worktree_locked(struct worktree *wt)
{
assert(!is_main_worktree(wt));
if (!wt->lock_reason_valid) {
struct strbuf path = STRBUF_INIT;
strbuf_addstr(&path, worktree_git_path(wt, "locked"));
if (file_exists(path.buf)) {
struct strbuf lock_reason = STRBUF_INIT;
if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
die_errno(_("failed to read '%s'"), path.buf);
strbuf_trim(&lock_reason);
wt->lock_reason = strbuf_detach(&lock_reason, NULL);
} else
wt->lock_reason = NULL;
wt->lock_reason_valid = 1;
strbuf_release(&path);
}
return wt->lock_reason;
}
int is_worktree_being_rebased(const struct worktree *wt,
const char *target)
{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_rebase(wt, &state) &&
((state.rebase_in_progress ||
state.rebase_interactive_in_progress) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/")));
free(state.branch);
free(state.onto);
return found_rebase;
}
int is_worktree_being_bisected(const struct worktree *wt,
const char *target)
{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_bisect(wt, &state) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/"));
free(state.branch);
return found_rebase;
}
/*
* note: this function should be able to detect shared symref even if
* HEAD is temporarily detached (e.g. in the middle of rebase or
* bisect). New commands that do similar things should update this
* function as well.
*/
const struct worktree *find_shared_symref(const char *symref,
const char *target)
{
const struct worktree *existing = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf sb = STRBUF_INIT;
static struct worktree **worktrees;
int i = 0;
if (worktrees)
free_worktrees(worktrees);
worktrees = get_worktrees(0);
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
if (wt->is_bare)
continue;
if (wt->is_detached && !strcmp(symref, "HEAD")) {
if (is_worktree_being_rebased(wt, target)) {
existing = wt;
break;
}
if (is_worktree_being_bisected(wt, target)) {
existing = wt;
break;
}
}
strbuf_reset(&path);
strbuf_reset(&sb);
strbuf_addf(&path, "%s/%s",
get_worktree_git_dir(wt),
symref);
if (parse_ref(path.buf, &sb, NULL)) {
continue;
}
if (!strcmp(sb.buf, target)) {
existing = wt;
break;
}
}
strbuf_release(&path);
strbuf_release(&sb);
return existing;
}
int submodule_uses_worktrees(const char *path)
{
char *submodule_gitdir;
struct strbuf sb = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int ret = 0;
struct repository_format format;
submodule_gitdir = git_pathdup_submodule(path, "%s", "");
if (!submodule_gitdir)
return 0;
/* The env would be set for the superproject. */
get_common_dir_noenv(&sb, submodule_gitdir);
/*
* The check below is only known to be good for repository format
* version 0 at the time of writing this code.
*/
strbuf_addstr(&sb, "/config");
read_repository_format(&format, sb.buf);
if (format.version != 0) {
strbuf_release(&sb);
return 1;
}
/* Replace config by worktrees. */
strbuf_setlen(&sb, sb.len - strlen("config"));
strbuf_addstr(&sb, "worktrees");
/* See if there is any file inside the worktrees directory. */
dir = opendir(sb.buf);
strbuf_release(&sb);
free(submodule_gitdir);
if (!dir)
return 0;
while ((d = readdir(dir)) != NULL) {
if (is_dot_or_dotdot(d->d_name))
continue;
ret = 1;
break;
}
closedir(dir);
return ret;
}