git/builtin/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

552 lines
14 KiB
C

#include "cache.h"
#include "builtin.h"
#include "dir.h"
#include "parse-options.h"
#include "argv-array.h"
#include "branch.h"
#include "refs.h"
#include "run-command.h"
#include "sigchain.h"
#include "refs.h"
#include "utf8.h"
#include "worktree.h"
static const char * const worktree_usage[] = {
N_("git worktree add [<options>] <path> [<branch>]"),
N_("git worktree list [<options>]"),
N_("git worktree lock [<options>] <path>"),
N_("git worktree prune [<options>]"),
N_("git worktree unlock <path>"),
NULL
};
struct add_opts {
int force;
int detach;
int checkout;
const char *new_branch;
int force_new_branch;
};
static int show_only;
static int verbose;
static unsigned long expire;
static int prune_worktree(const char *id, struct strbuf *reason)
{
struct stat st;
char *path;
int fd, len;
if (!is_directory(git_path("worktrees/%s", id))) {
strbuf_addf(reason, _("Removing worktrees/%s: not a valid directory"), id);
return 1;
}
if (file_exists(git_path("worktrees/%s/locked", id)))
return 0;
if (stat(git_path("worktrees/%s/gitdir", id), &st)) {
strbuf_addf(reason, _("Removing worktrees/%s: gitdir file does not exist"), id);
return 1;
}
fd = open(git_path("worktrees/%s/gitdir", id), O_RDONLY);
if (fd < 0) {
strbuf_addf(reason, _("Removing worktrees/%s: unable to read gitdir file (%s)"),
id, strerror(errno));
return 1;
}
len = st.st_size;
path = xmallocz(len);
read_in_full(fd, path, len);
close(fd);
while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
len--;
if (!len) {
strbuf_addf(reason, _("Removing worktrees/%s: invalid gitdir file"), id);
free(path);
return 1;
}
path[len] = '\0';
if (!file_exists(path)) {
struct stat st_link;
free(path);
/*
* the repo is moved manually and has not been
* accessed since?
*/
if (!stat(git_path("worktrees/%s/link", id), &st_link) &&
st_link.st_nlink > 1)
return 0;
if (st.st_mtime <= expire) {
strbuf_addf(reason, _("Removing worktrees/%s: gitdir file points to non-existent location"), id);
return 1;
} else {
return 0;
}
}
free(path);
return 0;
}
static void prune_worktrees(void)
{
struct strbuf reason = STRBUF_INIT;
struct strbuf path = STRBUF_INIT;
DIR *dir = opendir(git_path("worktrees"));
struct dirent *d;
int ret;
if (!dir)
return;
while ((d = readdir(dir)) != NULL) {
if (is_dot_or_dotdot(d->d_name))
continue;
strbuf_reset(&reason);
if (!prune_worktree(d->d_name, &reason))
continue;
if (show_only || verbose)
printf("%s\n", reason.buf);
if (show_only)
continue;
strbuf_reset(&path);
strbuf_addstr(&path, git_path("worktrees/%s", d->d_name));
ret = remove_dir_recursively(&path, 0);
if (ret < 0 && errno == ENOTDIR)
ret = unlink(path.buf);
if (ret)
error_errno(_("failed to remove '%s'"), path.buf);
}
closedir(dir);
if (!show_only)
rmdir(git_path("worktrees"));
strbuf_release(&reason);
strbuf_release(&path);
}
static int prune(int ac, const char **av, const char *prefix)
{
struct option options[] = {
OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
OPT__VERBOSE(&verbose, N_("report pruned working trees")),
OPT_EXPIRY_DATE(0, "expire", &expire,
N_("expire working trees older than <time>")),
OPT_END()
};
expire = ULONG_MAX;
ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
if (ac)
usage_with_options(worktree_usage, options);
prune_worktrees();
return 0;
}
static char *junk_work_tree;
static char *junk_git_dir;
static int is_junk;
static pid_t junk_pid;
static void remove_junk(void)
{
struct strbuf sb = STRBUF_INIT;
if (!is_junk || getpid() != junk_pid)
return;
if (junk_git_dir) {
strbuf_addstr(&sb, junk_git_dir);
remove_dir_recursively(&sb, 0);
strbuf_reset(&sb);
}
if (junk_work_tree) {
strbuf_addstr(&sb, junk_work_tree);
remove_dir_recursively(&sb, 0);
}
strbuf_release(&sb);
}
static void remove_junk_on_signal(int signo)
{
remove_junk();
sigchain_pop(signo);
raise(signo);
}
static const char *worktree_basename(const char *path, int *olen)
{
const char *name;
int len;
len = strlen(path);
while (len && is_dir_sep(path[len - 1]))
len--;
for (name = path + len - 1; name > path; name--)
if (is_dir_sep(*name)) {
name++;
break;
}
*olen = len;
return name;
}
static int add_worktree(const char *path, const char *refname,
const struct add_opts *opts)
{
struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT;
struct strbuf sb = STRBUF_INIT;
const char *name;
struct stat st;
struct child_process cp = CHILD_PROCESS_INIT;
struct argv_array child_env = ARGV_ARRAY_INIT;
int counter = 0, len, ret;
struct strbuf symref = STRBUF_INIT;
struct commit *commit = NULL;
if (file_exists(path) && !is_empty_dir(path))
die(_("'%s' already exists"), path);
/* is 'refname' a branch or commit? */
if (!opts->detach && !strbuf_check_branch_ref(&symref, refname) &&
ref_exists(symref.buf)) { /* it's a branch */
if (!opts->force)
die_if_checked_out(symref.buf, 0);
} else { /* must be a commit */
commit = lookup_commit_reference_by_name(refname);
if (!commit)
die(_("invalid reference: %s"), refname);
}
name = worktree_basename(path, &len);
strbuf_addstr(&sb_repo,
git_path("worktrees/%.*s", (int)(path + len - name), name));
len = sb_repo.len;
if (safe_create_leading_directories_const(sb_repo.buf))
die_errno(_("could not create leading directories of '%s'"),
sb_repo.buf);
while (!stat(sb_repo.buf, &st)) {
counter++;
strbuf_setlen(&sb_repo, len);
strbuf_addf(&sb_repo, "%d", counter);
}
name = strrchr(sb_repo.buf, '/') + 1;
junk_pid = getpid();
atexit(remove_junk);
sigchain_push_common(remove_junk_on_signal);
if (mkdir(sb_repo.buf, 0777))
die_errno(_("could not create directory of '%s'"), sb_repo.buf);
junk_git_dir = xstrdup(sb_repo.buf);
is_junk = 1;
/*
* lock the incomplete repo so prune won't delete it, unlock
* after the preparation is over.
*/
strbuf_addf(&sb, "%s/locked", sb_repo.buf);
write_file(sb.buf, "initializing");
strbuf_addf(&sb_git, "%s/.git", path);
if (safe_create_leading_directories_const(sb_git.buf))
die_errno(_("could not create leading directories of '%s'"),
sb_git.buf);
junk_work_tree = xstrdup(path);
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/gitdir", sb_repo.buf);
write_file(sb.buf, "%s", real_path(sb_git.buf));
write_file(sb_git.buf, "gitdir: %s/worktrees/%s",
real_path(get_git_common_dir()), name);
/*
* This is to keep resolve_ref() happy. We need a valid HEAD
* or is_git_directory() will reject the directory. Any value which
* looks like an object ID will do since it will be immediately
* replaced by the symbolic-ref or update-ref invocation in the new
* worktree.
*/
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/HEAD", sb_repo.buf);
write_file(sb.buf, "%s", sha1_to_hex(null_sha1));
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/commondir", sb_repo.buf);
write_file(sb.buf, "../..");
fprintf_ln(stderr, _("Preparing %s (identifier %s)"), path, name);
argv_array_pushf(&child_env, "%s=%s", GIT_DIR_ENVIRONMENT, sb_git.buf);
argv_array_pushf(&child_env, "%s=%s", GIT_WORK_TREE_ENVIRONMENT, path);
cp.git_cmd = 1;
if (commit)
argv_array_pushl(&cp.args, "update-ref", "HEAD",
oid_to_hex(&commit->object.oid), NULL);
else
argv_array_pushl(&cp.args, "symbolic-ref", "HEAD",
symref.buf, NULL);
cp.env = child_env.argv;
ret = run_command(&cp);
if (ret)
goto done;
if (opts->checkout) {
cp.argv = NULL;
argv_array_clear(&cp.args);
argv_array_pushl(&cp.args, "reset", "--hard", NULL);
cp.env = child_env.argv;
ret = run_command(&cp);
if (ret)
goto done;
}
is_junk = 0;
free(junk_work_tree);
free(junk_git_dir);
junk_work_tree = NULL;
junk_git_dir = NULL;
done:
strbuf_reset(&sb);
strbuf_addf(&sb, "%s/locked", sb_repo.buf);
unlink_or_warn(sb.buf);
argv_array_clear(&child_env);
strbuf_release(&sb);
strbuf_release(&symref);
strbuf_release(&sb_repo);
strbuf_release(&sb_git);
return ret;
}
static int add(int ac, const char **av, const char *prefix)
{
struct add_opts opts;
const char *new_branch_force = NULL;
char *path;
const char *branch;
struct option options[] = {
OPT__FORCE(&opts.force, N_("checkout <branch> even if already checked out in other worktree")),
OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
N_("create a new branch")),
OPT_STRING('B', NULL, &new_branch_force, N_("branch"),
N_("create or reset a branch")),
OPT_BOOL(0, "detach", &opts.detach, N_("detach HEAD at named commit")),
OPT_BOOL(0, "checkout", &opts.checkout, N_("populate the new working tree")),
OPT_END()
};
memset(&opts, 0, sizeof(opts));
opts.checkout = 1;
ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
if (!!opts.detach + !!opts.new_branch + !!new_branch_force > 1)
die(_("-b, -B, and --detach are mutually exclusive"));
if (ac < 1 || ac > 2)
usage_with_options(worktree_usage, options);
path = prefix_filename(prefix, av[0]);
branch = ac < 2 ? "HEAD" : av[1];
if (!strcmp(branch, "-"))
branch = "@{-1}";
opts.force_new_branch = !!new_branch_force;
if (opts.force_new_branch) {
struct strbuf symref = STRBUF_INIT;
opts.new_branch = new_branch_force;
if (!opts.force &&
!strbuf_check_branch_ref(&symref, opts.new_branch) &&
ref_exists(symref.buf))
die_if_checked_out(symref.buf, 0);
strbuf_release(&symref);
}
if (ac < 2 && !opts.new_branch && !opts.detach) {
int n;
const char *s = worktree_basename(path, &n);
opts.new_branch = xstrndup(s, n);
}
if (opts.new_branch) {
struct child_process cp = CHILD_PROCESS_INIT;
cp.git_cmd = 1;
argv_array_push(&cp.args, "branch");
if (opts.force_new_branch)
argv_array_push(&cp.args, "--force");
argv_array_push(&cp.args, opts.new_branch);
argv_array_push(&cp.args, branch);
if (run_command(&cp))
return -1;
branch = opts.new_branch;
}
return add_worktree(path, branch, &opts);
}
static void show_worktree_porcelain(struct worktree *wt)
{
printf("worktree %s\n", wt->path);
if (wt->is_bare)
printf("bare\n");
else {
printf("HEAD %s\n", sha1_to_hex(wt->head_sha1));
if (wt->is_detached)
printf("detached\n");
else if (wt->head_ref)
printf("branch %s\n", wt->head_ref);
}
printf("\n");
}
static void show_worktree(struct worktree *wt, int path_maxlen, int abbrev_len)
{
struct strbuf sb = STRBUF_INIT;
int cur_path_len = strlen(wt->path);
int path_adj = cur_path_len - utf8_strwidth(wt->path);
strbuf_addf(&sb, "%-*s ", 1 + path_maxlen + path_adj, wt->path);
if (wt->is_bare)
strbuf_addstr(&sb, "(bare)");
else {
strbuf_addf(&sb, "%-*s ", abbrev_len,
find_unique_abbrev(wt->head_sha1, DEFAULT_ABBREV));
if (wt->is_detached)
strbuf_addstr(&sb, "(detached HEAD)");
else if (wt->head_ref)
strbuf_addf(&sb, "[%s]", shorten_unambiguous_ref(wt->head_ref, 0));
else
strbuf_addstr(&sb, "(error)");
}
printf("%s\n", sb.buf);
strbuf_release(&sb);
}
static void measure_widths(struct worktree **wt, int *abbrev, int *maxlen)
{
int i;
for (i = 0; wt[i]; i++) {
int sha1_len;
int path_len = strlen(wt[i]->path);
if (path_len > *maxlen)
*maxlen = path_len;
sha1_len = strlen(find_unique_abbrev(wt[i]->head_sha1, *abbrev));
if (sha1_len > *abbrev)
*abbrev = sha1_len;
}
}
static int list(int ac, const char **av, const char *prefix)
{
int porcelain = 0;
struct option options[] = {
OPT_BOOL(0, "porcelain", &porcelain, N_("machine-readable output")),
OPT_END()
};
ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
if (ac)
usage_with_options(worktree_usage, options);
else {
struct worktree **worktrees = get_worktrees(GWT_SORT_LINKED);
int path_maxlen = 0, abbrev = DEFAULT_ABBREV, i;
if (!porcelain)
measure_widths(worktrees, &abbrev, &path_maxlen);
for (i = 0; worktrees[i]; i++) {
if (porcelain)
show_worktree_porcelain(worktrees[i]);
else
show_worktree(worktrees[i], path_maxlen, abbrev);
}
free_worktrees(worktrees);
}
return 0;
}
static int lock_worktree(int ac, const char **av, const char *prefix)
{
const char *reason = "", *old_reason;
struct option options[] = {
OPT_STRING(0, "reason", &reason, N_("string"),
N_("reason for locking")),
OPT_END()
};
struct worktree **worktrees, *wt;
ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
if (ac != 1)
usage_with_options(worktree_usage, options);
worktrees = get_worktrees(0);
wt = find_worktree(worktrees, prefix, av[0]);
if (!wt)
die(_("'%s' is not a working tree"), av[0]);
if (is_main_worktree(wt))
die(_("The main working tree cannot be locked or unlocked"));
old_reason = is_worktree_locked(wt);
if (old_reason) {
if (*old_reason)
die(_("'%s' is already locked, reason: %s"),
av[0], old_reason);
die(_("'%s' is already locked"), av[0]);
}
write_file(git_common_path("worktrees/%s/locked", wt->id),
"%s", reason);
free_worktrees(worktrees);
return 0;
}
static int unlock_worktree(int ac, const char **av, const char *prefix)
{
struct option options[] = {
OPT_END()
};
struct worktree **worktrees, *wt;
int ret;
ac = parse_options(ac, av, prefix, options, worktree_usage, 0);
if (ac != 1)
usage_with_options(worktree_usage, options);
worktrees = get_worktrees(0);
wt = find_worktree(worktrees, prefix, av[0]);
if (!wt)
die(_("'%s' is not a working tree"), av[0]);
if (is_main_worktree(wt))
die(_("The main working tree cannot be locked or unlocked"));
if (!is_worktree_locked(wt))
die(_("'%s' is not locked"), av[0]);
ret = unlink_or_warn(git_common_path("worktrees/%s/locked", wt->id));
free_worktrees(worktrees);
return ret;
}
int cmd_worktree(int ac, const char **av, const char *prefix)
{
struct option options[] = {
OPT_END()
};
git_config(git_default_config, NULL);
if (ac < 2)
usage_with_options(worktree_usage, options);
if (!prefix)
prefix = "";
if (!strcmp(av[1], "add"))
return add(ac - 1, av + 1, prefix);
if (!strcmp(av[1], "prune"))
return prune(ac - 1, av + 1, prefix);
if (!strcmp(av[1], "list"))
return list(ac - 1, av + 1, prefix);
if (!strcmp(av[1], "lock"))
return lock_worktree(ac - 1, av + 1, prefix);
if (!strcmp(av[1], "unlock"))
return unlock_worktree(ac - 1, av + 1, prefix);
usage_with_options(worktree_usage, options);
}