git/setup.c
Jonathan Nieder 4868b2ea17 Subject: setup: officially support --work-tree without --git-dir
The original intention of --work-tree was to allow people to work in a
subdirectory of their working tree that does not have an embedded .git
directory.  Because their working tree, which their $cwd was in, did not
have an embedded .git, they needed to use $GIT_DIR to specify where it is,
and because this meant there was no way to discover where the root level
of the working tree was, so we needed to add $GIT_WORK_TREE to tell git
where it was.

However, this facility has long been (mis)used by people's scripts to
start git from a working tree _with_ an embedded .git directory, let git
find .git directory, and then pretend as if an unrelated directory were
the associated working tree of the .git directory found by the discovery
process.  It happens to work in simple cases, and is not worth causing
"regression" to these scripts.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-01-21 14:31:24 -08:00

695 lines
18 KiB
C

#include "cache.h"
#include "dir.h"
static int inside_git_dir = -1;
static int inside_work_tree = -1;
char *prefix_path(const char *prefix, int len, const char *path)
{
const char *orig = path;
char *sanitized = xmalloc(len + strlen(path) + 1);
if (is_absolute_path(orig))
strcpy(sanitized, path);
else {
if (len)
memcpy(sanitized, prefix, len);
strcpy(sanitized + len, path);
}
if (normalize_path_copy(sanitized, sanitized))
goto error_out;
if (is_absolute_path(orig)) {
size_t root_len, len, total;
const char *work_tree = get_git_work_tree();
if (!work_tree)
goto error_out;
len = strlen(work_tree);
root_len = offset_1st_component(work_tree);
total = strlen(sanitized) + 1;
if (strncmp(sanitized, work_tree, len) ||
(len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
error_out:
die("'%s' is outside repository", orig);
}
if (sanitized[len] == '/')
len++;
memmove(sanitized, sanitized + len, total - len);
}
return sanitized;
}
/*
* Unlike prefix_path, this should be used if the named file does
* not have to interact with index entry; i.e. name of a random file
* on the filesystem.
*/
const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
{
static char path[PATH_MAX];
#ifndef WIN32
if (!pfx_len || is_absolute_path(arg))
return arg;
memcpy(path, pfx, pfx_len);
strcpy(path + pfx_len, arg);
#else
char *p;
/* don't add prefix to absolute paths, but still replace '\' by '/' */
if (is_absolute_path(arg))
pfx_len = 0;
else if (pfx_len)
memcpy(path, pfx, pfx_len);
strcpy(path + pfx_len, arg);
for (p = path + pfx_len; *p; p++)
if (*p == '\\')
*p = '/';
#endif
return path;
}
int check_filename(const char *prefix, const char *arg)
{
const char *name;
struct stat st;
name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
if (!lstat(name, &st))
return 1; /* file exists */
if (errno == ENOENT || errno == ENOTDIR)
return 0; /* file does not exist */
die_errno("failed to stat '%s'", arg);
}
static void NORETURN die_verify_filename(const char *prefix, const char *arg)
{
unsigned char sha1[20];
unsigned mode;
/* try a detailed diagnostic ... */
get_sha1_with_mode_1(arg, sha1, &mode, 0, prefix);
/* ... or fall back the most general message. */
die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
"Use '--' to separate paths from revisions", arg);
}
/*
* Verify a filename that we got as an argument for a pathspec
* entry. Note that a filename that begins with "-" never verifies
* as true, because even if such a filename were to exist, we want
* it to be preceded by the "--" marker (or we want the user to
* use a format like "./-filename")
*/
void verify_filename(const char *prefix, const char *arg)
{
if (*arg == '-')
die("bad flag '%s' used after filename", arg);
if (check_filename(prefix, arg))
return;
die_verify_filename(prefix, arg);
}
/*
* Opposite of the above: the command line did not have -- marker
* and we parsed the arg as a refname. It should not be interpretable
* as a filename.
*/
void verify_non_filename(const char *prefix, const char *arg)
{
if (!is_inside_work_tree() || is_inside_git_dir())
return;
if (*arg == '-')
return; /* flag */
if (!check_filename(prefix, arg))
return;
die("ambiguous argument '%s': both revision and filename\n"
"Use '--' to separate filenames from revisions", arg);
}
const char **get_pathspec(const char *prefix, const char **pathspec)
{
const char *entry = *pathspec;
const char **src, **dst;
int prefixlen;
if (!prefix && !entry)
return NULL;
if (!entry) {
static const char *spec[2];
spec[0] = prefix;
spec[1] = NULL;
return spec;
}
/* Otherwise we have to re-write the entries.. */
src = pathspec;
dst = pathspec;
prefixlen = prefix ? strlen(prefix) : 0;
while (*src) {
const char *p = prefix_path(prefix, prefixlen, *src);
*(dst++) = p;
src++;
}
*dst = NULL;
if (!*pathspec)
return NULL;
return pathspec;
}
/*
* Test if it looks like we're at a git directory.
* We want to see:
*
* - either an objects/ directory _or_ the proper
* GIT_OBJECT_DIRECTORY environment variable
* - a refs/ directory
* - either a HEAD symlink or a HEAD file that is formatted as
* a proper "ref:", or a regular file HEAD that has a properly
* formatted sha1 object name.
*/
static int is_git_directory(const char *suspect)
{
char path[PATH_MAX];
size_t len = strlen(suspect);
if (PATH_MAX <= len + strlen("/objects"))
die("Too long path: %.*s", 60, suspect);
strcpy(path, suspect);
if (getenv(DB_ENVIRONMENT)) {
if (access(getenv(DB_ENVIRONMENT), X_OK))
return 0;
}
else {
strcpy(path + len, "/objects");
if (access(path, X_OK))
return 0;
}
strcpy(path + len, "/refs");
if (access(path, X_OK))
return 0;
strcpy(path + len, "/HEAD");
if (validate_headref(path))
return 0;
return 1;
}
int is_inside_git_dir(void)
{
if (inside_git_dir < 0)
inside_git_dir = is_inside_dir(get_git_dir());
return inside_git_dir;
}
int is_inside_work_tree(void)
{
if (inside_work_tree < 0)
inside_work_tree = is_inside_dir(get_git_work_tree());
return inside_work_tree;
}
void setup_work_tree(void)
{
const char *work_tree, *git_dir;
static int initialized = 0;
if (initialized)
return;
work_tree = get_git_work_tree();
git_dir = get_git_dir();
if (!is_absolute_path(git_dir))
git_dir = make_absolute_path(git_dir);
if (!work_tree || chdir(work_tree))
die("This operation must be run in a work tree");
/*
* Make sure subsequent git processes find correct worktree
* if $GIT_WORK_TREE is set relative
*/
if (getenv(GIT_WORK_TREE_ENVIRONMENT))
setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
set_git_dir(make_relative_path(git_dir, work_tree));
initialized = 1;
}
static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
{
char repo_config[PATH_MAX+1];
/*
* git_config() can't be used here because it calls git_pathdup()
* to get $GIT_CONFIG/config. That call will make setup_git_env()
* set git_dir to ".git".
*
* We are in gitdir setup, no git dir has been found useable yet.
* Use a gentler version of git_config() to check if this repo
* is a good one.
*/
snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
git_config_early(check_repository_format_version, NULL, repo_config);
if (GIT_REPO_VERSION < repository_format_version) {
if (!nongit_ok)
die ("Expected git repo version <= %d, found %d",
GIT_REPO_VERSION, repository_format_version);
warning("Expected git repo version <= %d, found %d",
GIT_REPO_VERSION, repository_format_version);
warning("Please upgrade Git");
*nongit_ok = -1;
return -1;
}
return 0;
}
/*
* Try to read the location of the git directory from the .git file,
* return path to git directory if found.
*/
const char *read_gitfile_gently(const char *path)
{
char *buf;
char *dir;
const char *slash;
struct stat st;
int fd;
size_t len;
if (stat(path, &st))
return NULL;
if (!S_ISREG(st.st_mode))
return NULL;
fd = open(path, O_RDONLY);
if (fd < 0)
die_errno("Error opening '%s'", path);
buf = xmalloc(st.st_size + 1);
len = read_in_full(fd, buf, st.st_size);
close(fd);
if (len != st.st_size)
die("Error reading %s", path);
buf[len] = '\0';
if (prefixcmp(buf, "gitdir: "))
die("Invalid gitfile format: %s", path);
while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
len--;
if (len < 9)
die("No path in gitfile: %s", path);
buf[len] = '\0';
dir = buf + 8;
if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
size_t pathlen = slash+1 - path;
size_t dirlen = pathlen + len - 8;
dir = xmalloc(dirlen + 1);
strncpy(dir, path, pathlen);
strncpy(dir + pathlen, buf + 8, len - 8);
dir[dirlen] = '\0';
free(buf);
buf = dir;
}
if (!is_git_directory(dir))
die("Not a git repository: %s", dir);
path = make_absolute_path(dir);
free(buf);
return path;
}
static const char *setup_explicit_git_dir(const char *gitdirenv,
char *cwd, int len,
int *nongit_ok)
{
const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
const char *worktree;
char *gitfile;
if (PATH_MAX - 40 < strlen(gitdirenv))
die("'$%s' too big", GIT_DIR_ENVIRONMENT);
gitfile = (char*)read_gitfile_gently(gitdirenv);
if (gitfile) {
gitfile = xstrdup(gitfile);
gitdirenv = gitfile;
}
if (!is_git_directory(gitdirenv)) {
if (nongit_ok) {
*nongit_ok = 1;
free(gitfile);
return NULL;
}
die("Not a git repository: '%s'", gitdirenv);
}
if (check_repository_format_gently(gitdirenv, nongit_ok)) {
free(gitfile);
return NULL;
}
/* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
if (work_tree_env)
set_git_work_tree(work_tree_env);
else if (is_bare_repository_cfg > 0) {
if (git_work_tree_cfg) /* #22.2, #30 */
die("core.bare and core.worktree do not make sense");
/* #18, #26 */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
else if (git_work_tree_cfg) { /* #6, #14 */
if (is_absolute_path(git_work_tree_cfg))
set_git_work_tree(git_work_tree_cfg);
else {
char core_worktree[PATH_MAX];
if (chdir(gitdirenv))
die_errno("Could not chdir to '%s'", gitdirenv);
if (chdir(git_work_tree_cfg))
die_errno("Could not chdir to '%s'", git_work_tree_cfg);
if (!getcwd(core_worktree, PATH_MAX))
die_errno("Could not get directory '%s'", git_work_tree_cfg);
if (chdir(cwd))
die_errno("Could not come back to cwd");
set_git_work_tree(core_worktree);
}
}
else /* #2, #10 */
set_git_work_tree(".");
/* set_git_work_tree() must have been called by now */
worktree = get_git_work_tree();
/* both get_git_work_tree() and cwd are already normalized */
if (!strcmp(cwd, worktree)) { /* cwd == worktree */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
if (!prefixcmp(cwd, worktree) &&
cwd[strlen(worktree)] == '/') { /* cwd inside worktree */
set_git_dir(make_absolute_path(gitdirenv));
if (chdir(worktree))
die_errno("Could not chdir to '%s'", worktree);
cwd[len++] = '/';
cwd[len] = '\0';
free(gitfile);
return cwd + strlen(worktree) + 1;
}
/* cwd outside worktree */
set_git_dir(gitdirenv);
free(gitfile);
return NULL;
}
static const char *setup_discovered_git_dir(const char *gitdir,
char *cwd, int offset, int len,
int *nongit_ok)
{
if (check_repository_format_gently(gitdir, nongit_ok))
return NULL;
/* --work-tree is set without --git-dir; use discovered one */
if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
if (offset != len && !is_absolute_path(gitdir))
gitdir = xstrdup(make_absolute_path(gitdir));
if (chdir(cwd))
die_errno("Could not come back to cwd");
return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
}
/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
if (is_bare_repository_cfg > 0) {
set_git_dir(offset == len ? gitdir : make_absolute_path(gitdir));
if (chdir(cwd))
die_errno("Could not come back to cwd");
return NULL;
}
/* #0, #1, #5, #8, #9, #12, #13 */
set_git_work_tree(".");
if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
set_git_dir(gitdir);
inside_git_dir = 0;
inside_work_tree = 1;
if (offset == len)
return NULL;
/* Make "offset" point to past the '/', and add a '/' at the end */
offset++;
cwd[len++] = '/';
cwd[len] = 0;
return cwd + offset;
}
/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
{
int root_len;
if (check_repository_format_gently(".", nongit_ok))
return NULL;
/* --work-tree is set without --git-dir; use discovered one */
if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
const char *gitdir;
gitdir = offset == len ? "." : xmemdupz(cwd, offset);
if (chdir(cwd))
die_errno("Could not come back to cwd");
return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
}
inside_git_dir = 1;
inside_work_tree = 0;
if (offset != len) {
if (chdir(cwd))
die_errno("Cannot come back to cwd");
root_len = offset_1st_component(cwd);
cwd[offset > root_len ? offset : root_len] = '\0';
set_git_dir(cwd);
}
else
set_git_dir(".");
return NULL;
}
static const char *setup_nongit(const char *cwd, int *nongit_ok)
{
if (!nongit_ok)
die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
if (chdir(cwd))
die_errno("Cannot come back to cwd");
*nongit_ok = 1;
return NULL;
}
static dev_t get_device_or_die(const char *path, const char *prefix)
{
struct stat buf;
if (stat(path, &buf))
die_errno("failed to stat '%s%s%s'",
prefix ? prefix : "",
prefix ? "/" : "", path);
return buf.st_dev;
}
/*
* We cannot decide in this function whether we are in the work tree or
* not, since the config can only be read _after_ this function was called.
*/
static const char *setup_git_directory_gently_1(int *nongit_ok)
{
const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
static char cwd[PATH_MAX+1];
const char *gitdirenv, *ret;
char *gitfile;
int len, offset, ceil_offset;
dev_t current_device = 0;
int one_filesystem = 1;
/*
* Let's assume that we are in a git repository.
* If it turns out later that we are somewhere else, the value will be
* updated accordingly.
*/
if (nongit_ok)
*nongit_ok = 0;
if (!getcwd(cwd, sizeof(cwd)-1))
die_errno("Unable to read current working directory");
offset = len = strlen(cwd);
/*
* If GIT_DIR is set explicitly, we're not going
* to do any discovery, but we still do repository
* validation.
*/
gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
if (gitdirenv)
return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
ceil_offset = 1;
/*
* Test in the following order (relative to the cwd):
* - .git (file containing "gitdir: <path>")
* - .git/
* - ./ (bare)
* - ../.git
* - ../.git/
* - ../ (bare)
* - ../../.git/
* etc.
*/
one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
if (one_filesystem)
current_device = get_device_or_die(".", NULL);
for (;;) {
gitfile = (char*)read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
if (gitfile)
gitdirenv = gitfile = xstrdup(gitfile);
else {
if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
}
if (gitdirenv) {
ret = setup_discovered_git_dir(gitdirenv,
cwd, offset, len,
nongit_ok);
free(gitfile);
return ret;
}
free(gitfile);
if (is_git_directory("."))
return setup_bare_git_dir(cwd, offset, len, nongit_ok);
while (--offset > ceil_offset && cwd[offset] != '/');
if (offset <= ceil_offset)
return setup_nongit(cwd, nongit_ok);
if (one_filesystem) {
dev_t parent_device = get_device_or_die("..", cwd);
if (parent_device != current_device) {
if (nongit_ok) {
if (chdir(cwd))
die_errno("Cannot come back to cwd");
*nongit_ok = 1;
return NULL;
}
cwd[offset] = '\0';
die("Not a git repository (or any parent up to mount parent %s)\n"
"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
}
}
if (chdir("..")) {
cwd[offset] = '\0';
die_errno("Cannot change to '%s/..'", cwd);
}
}
}
const char *setup_git_directory_gently(int *nongit_ok)
{
const char *prefix;
prefix = setup_git_directory_gently_1(nongit_ok);
if (startup_info) {
startup_info->have_repository = !nongit_ok || !*nongit_ok;
startup_info->prefix = prefix;
}
return prefix;
}
int git_config_perm(const char *var, const char *value)
{
int i;
char *endptr;
if (value == NULL)
return PERM_GROUP;
if (!strcmp(value, "umask"))
return PERM_UMASK;
if (!strcmp(value, "group"))
return PERM_GROUP;
if (!strcmp(value, "all") ||
!strcmp(value, "world") ||
!strcmp(value, "everybody"))
return PERM_EVERYBODY;
/* Parse octal numbers */
i = strtol(value, &endptr, 8);
/* If not an octal number, maybe true/false? */
if (*endptr != 0)
return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
/*
* Treat values 0, 1 and 2 as compatibility cases, otherwise it is
* a chmod value to restrict to.
*/
switch (i) {
case PERM_UMASK: /* 0 */
return PERM_UMASK;
case OLD_PERM_GROUP: /* 1 */
return PERM_GROUP;
case OLD_PERM_EVERYBODY: /* 2 */
return PERM_EVERYBODY;
}
/* A filemode value was given: 0xxx */
if ((i & 0600) != 0600)
die("Problem with core.sharedRepository filemode value "
"(0%.3o).\nThe owner of files must always have "
"read and write permissions.", i);
/*
* Mask filemode value. Others can not get write permission.
* x flags for directories are handled separately.
*/
return -(i & 0666);
}
int check_repository_format_version(const char *var, const char *value, void *cb)
{
if (strcmp(var, "core.repositoryformatversion") == 0)
repository_format_version = git_config_int(var, value);
else if (strcmp(var, "core.sharedrepository") == 0)
shared_repository = git_config_perm(var, value);
else if (strcmp(var, "core.bare") == 0) {
is_bare_repository_cfg = git_config_bool(var, value);
if (is_bare_repository_cfg == 1)
inside_work_tree = -1;
} else if (strcmp(var, "core.worktree") == 0) {
if (!value)
return config_error_nonbool(var);
free(git_work_tree_cfg);
git_work_tree_cfg = xstrdup(value);
inside_work_tree = -1;
}
return 0;
}
int check_repository_format(void)
{
return check_repository_format_gently(get_git_dir(), NULL);
}
/*
* Returns the "prefix", a path to the current working directory
* relative to the work tree root, or NULL, if the current working
* directory is not a strict subdirectory of the work tree root. The
* prefix always ends with a '/' character.
*/
const char *setup_git_directory(void)
{
return setup_git_directory_gently(NULL);
}