setup.c - pub/scm/git/git - Git at Google

 #include "cache.h"
 #include "dir.h"

 static int inside_git_dir = -1;
 static int inside_work_tree = -1;

 const char *prefix_path(const char *prefix, int len, const char *path)
 {
 	const char *orig = path;
 	for (;;) {
 		char c;
 		if (*path != '.')
 			break;
 		c = path[1];
 		/* "." */
 		if (!c) {
 			path++;
 			break;
 		}
 		/* "./" */
 		if (c == '/') {
 			path += 2;
 			continue;
 		}
 		if (c != '.')
 			break;
 		c = path[2];
 		if (!c)
 			path += 2;
 		else if (c == '/')
 			path += 3;
 		else
 			break;
 		/* ".." and "../" */
 		/* Remove last component of the prefix */
 		do {
 			if (!len)
 				die("'%s' is outside repository", orig);
 			len--;
 		} while (len && prefix[len-1] != '/');
 		continue;
 	}
 	if (len) {
 		int speclen = strlen(path);
 		char *n = xmalloc(speclen + len + 1);

 		memcpy(n, prefix, len);
 		memcpy(n + len, path, speclen+1);
 		path = n;
 	}
 	return path;
 }

 /*
  * 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];
 	if (!pfx || !*pfx || arg[0] == '/')
 		return arg;
 	memcpy(path, pfx, pfx_len);
 	strcpy(path + pfx_len, arg);
 	return path;
 }

 /*
  * 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)
 {
 	const char *name;
 	struct stat st;

 	if (*arg == '-')
 		die("bad flag '%s' used after filename", arg);
 	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 	if (!lstat(name, &st))
 		return;
 	if (errno == ENOENT)
 		die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 		    "Use '--' to separate paths from revisions", arg);
 	die("'%s': %s", arg, strerror(errno));
 }

 /*
  * 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)
 {
 	const char *name;
 	struct stat st;

 	if (!is_inside_work_tree() || is_inside_git_dir())
 		return;
 	if (*arg == '-')
 		return; /* flag */
 	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
 	if (!lstat(name, &st))
 		die("ambiguous argument '%s': both revision and filename\n"
 		    "Use '--' to separate filenames from revisions", arg);
 	if (errno != ENOENT && errno != ENOTDIR)
 		die("'%s': %s", arg, strerror(errno));
 }

 const char **get_pathspec(const char *prefix, const char **pathspec)
 {
 	const char *entry = *pathspec;
 	const char **p;
 	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.. */
 	p = pathspec;
 	prefixlen = prefix ? strlen(prefix) : 0;
 	do {
 		*p = prefix_path(prefix, prefixlen, entry);
 	} while ((entry = *++p) != NULL);
 	return (const char **) pathspec;
 }

 /*
  * Test if it looks like we're at a git directory.
  * We want to see:
  *
  *  - either a 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);

 	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;
 }

 /*
  * set_work_tree() is only ever called if you set GIT_DIR explicitely.
  * The old behaviour (which we retain here) is to set the work tree root
  * to the cwd, unless overridden by the config, the command line, or
  * GIT_WORK_TREE.
  */
 static const char *set_work_tree(const char *dir)
 {
 	char buffer[PATH_MAX + 1];

 	if (!getcwd(buffer, sizeof(buffer)))
 		die ("Could not get the current working directory");
 	git_work_tree_cfg = xstrdup(buffer);
 	inside_work_tree = 1;

 	return NULL;
 }

 /*
  * 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.
  */
 const char *setup_git_directory_gently(int *nongit_ok)
 {
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	static char cwd[PATH_MAX+1];
 	const char *gitdirenv;
 	int len, offset;

 	/*
 	 * 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) {
 		if (PATH_MAX - 40 < strlen(gitdirenv))
 			die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 		if (is_git_directory(gitdirenv)) {
 			static char buffer[1024 + 1];
 			const char *retval;

 			if (!work_tree_env)
 				return set_work_tree(gitdirenv);
 			retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
 					get_git_work_tree());
 			if (!retval || !*retval)
 				return NULL;
 			set_git_dir(make_absolute_path(gitdirenv));
 			if (chdir(work_tree_env) < 0)
 				die ("Could not chdir to %s", work_tree_env);
 			strcat(buffer, "/");
 			return retval;
 		}
 		if (nongit_ok) {
 			*nongit_ok = 1;
 			return NULL;
 		}
 		die("Not a git repository: '%s'", gitdirenv);
 	}

 	if (!getcwd(cwd, sizeof(cwd)-1))
 		die("Unable to read current working directory");

 	/*
 	 * Test in the following order (relative to the cwd):
 	 * - .git/
 	 * - ./ (bare)
 	 * - ../.git/
 	 * - ../ (bare)
 	 * - ../../.git/
 	 *   etc.
 	 */
 	offset = len = strlen(cwd);
 	for (;;) {
 		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 			break;
 		if (is_git_directory(".")) {
 			inside_git_dir = 1;
 			if (!work_tree_env)
 				inside_work_tree = 0;
 			setenv(GIT_DIR_ENVIRONMENT, ".", 1);
 			return NULL;
 		}
 		chdir("..");
 		do {
 			if (!offset) {
 				if (nongit_ok) {
 					if (chdir(cwd))
 						die("Cannot come back to cwd");
 					*nongit_ok = 1;
 					return NULL;
 				}
 				die("Not a git repository");
 			}
 		} while (cwd[--offset] != '/');
 	}

 	inside_git_dir = 0;
 	if (!work_tree_env)
 		inside_work_tree = 1;
 	git_work_tree_cfg = xstrndup(cwd, offset);
 	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;
 }

 int git_config_perm(const char *var, const char *value)
 {
 	if (value) {
 		int i;
 		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;
 		i = atoi(value);
 		if (i > 1)
 			return i;
 	}
 	return git_config_bool(var, value);
 }

 int check_repository_format_version(const char *var, const char *value)
 {
 	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 (git_work_tree_cfg)
 			free(git_work_tree_cfg);
 		git_work_tree_cfg = xstrdup(value);
 		inside_work_tree = -1;
 	}
 	return 0;
 }

 int check_repository_format(void)
 {
 	git_config(check_repository_format_version);
 	if (GIT_REPO_VERSION < repository_format_version)
 		die ("Expected git repo version <= %d, found %d",
 		     GIT_REPO_VERSION, repository_format_version);
 	return 0;
 }

 const char *setup_git_directory(void)
 {
 	const char *retval = setup_git_directory_gently(NULL);
 	check_repository_format();

 	/* If the work tree is not the default one, recompute prefix */
 	if (inside_work_tree < 0) {
 		static char buffer[PATH_MAX + 1];
 		char *rel;
 		if (retval && chdir(retval))
 			die ("Could not jump back into original cwd");
 		rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
 		return rel && *rel ? strcat(rel, "/") : NULL;
 	}

 	return retval;
 }
	#include "cache.h"
	#include "dir.h"

	static int inside_git_dir = -1;
	static int inside_work_tree = -1;

	const char prefix_path(const char prefix, int len, const char *path)
	{
	const char *orig = path;
	for (;;) {
	char c;
	if (*path != '.')
	break;
	c = path[1];
	/* "." */
	if (!c) {
	path++;
	break;
	}
	/* "./" */
	if (c == '/') {
	path += 2;
	continue;
	}
	if (c != '.')
	break;
	c = path[2];
	if (!c)
	path += 2;
	else if (c == '/')
	path += 3;
	else
	break;
	/* ".." and "../" */
	/* Remove last component of the prefix */
	do {
	if (!len)
	die("'%s' is outside repository", orig);
	len--;
	} while (len && prefix[len-1] != '/');
	continue;
	}
	if (len) {
	int speclen = strlen(path);
	char *n = xmalloc(speclen + len + 1);

	memcpy(n, prefix, len);
	memcpy(n + len, path, speclen+1);
	path = n;
	}
	return path;
	}

	/*
	* 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];
	if (!pfx \|\| !*pfx \|\| arg[0] == '/')
	return arg;
	memcpy(path, pfx, pfx_len);
	strcpy(path + pfx_len, arg);
	return path;
	}

	/*
	* 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)
	{
	const char *name;
	struct stat st;

	if (*arg == '-')
	die("bad flag '%s' used after filename", arg);
	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
	if (!lstat(name, &st))
	return;
	if (errno == ENOENT)
	die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
	"Use '--' to separate paths from revisions", arg);
	die("'%s': %s", arg, strerror(errno));
	}

	/*
	* 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)
	{
	const char *name;
	struct stat st;

	if (!is_inside_work_tree() \|\| is_inside_git_dir())
	return;
	if (*arg == '-')
	return; /* flag */
	name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
	if (!lstat(name, &st))
	die("ambiguous argument '%s': both revision and filename\n"
	"Use '--' to separate filenames from revisions", arg);
	if (errno != ENOENT && errno != ENOTDIR)
	die("'%s': %s", arg, strerror(errno));
	}

	const char *get_pathspec(const char prefix, const char **pathspec)
	{
	const char entry = pathspec;
	const char **p;
	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.. */
	p = pathspec;
	prefixlen = prefix ? strlen(prefix) : 0;
	do {
	*p = prefix_path(prefix, prefixlen, entry);
	} while ((entry = *++p) != NULL);
	return (const char **) pathspec;
	}

	/*
	* Test if it looks like we're at a git directory.
	* We want to see:
	*
	* - either a 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);

	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;
	}

	/*
	* set_work_tree() is only ever called if you set GIT_DIR explicitely.
	* The old behaviour (which we retain here) is to set the work tree root
	* to the cwd, unless overridden by the config, the command line, or
	* GIT_WORK_TREE.
	*/
	static const char set_work_tree(const char dir)
	{
	char buffer[PATH_MAX + 1];

	if (!getcwd(buffer, sizeof(buffer)))
	die ("Could not get the current working directory");
	git_work_tree_cfg = xstrdup(buffer);
	inside_work_tree = 1;

	return NULL;
	}

	/*
	* 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.
	*/
	const char setup_git_directory_gently(int nongit_ok)
	{
	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
	static char cwd[PATH_MAX+1];
	const char *gitdirenv;
	int len, offset;

	/*
	* 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) {
	if (PATH_MAX - 40 < strlen(gitdirenv))
	die("'$%s' too big", GIT_DIR_ENVIRONMENT);
	if (is_git_directory(gitdirenv)) {
	static char buffer[1024 + 1];
	const char *retval;

	if (!work_tree_env)
	return set_work_tree(gitdirenv);
	retval = get_relative_cwd(buffer, sizeof(buffer) - 1,
	get_git_work_tree());
	if (!retval \|\| !*retval)
	return NULL;
	set_git_dir(make_absolute_path(gitdirenv));
	if (chdir(work_tree_env) < 0)
	die ("Could not chdir to %s", work_tree_env);
	strcat(buffer, "/");
	return retval;
	}
	if (nongit_ok) {
	*nongit_ok = 1;
	return NULL;
	}
	die("Not a git repository: '%s'", gitdirenv);
	}

	if (!getcwd(cwd, sizeof(cwd)-1))
	die("Unable to read current working directory");

	/*
	* Test in the following order (relative to the cwd):
	* - .git/
	* - ./ (bare)
	* - ../.git/
	* - ../ (bare)
	* - ../../.git/
	* etc.
	*/
	offset = len = strlen(cwd);
	for (;;) {
	if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
	break;
	if (is_git_directory(".")) {
	inside_git_dir = 1;
	if (!work_tree_env)
	inside_work_tree = 0;
	setenv(GIT_DIR_ENVIRONMENT, ".", 1);
	return NULL;
	}
	chdir("..");
	do {
	if (!offset) {
	if (nongit_ok) {
	if (chdir(cwd))
	die("Cannot come back to cwd");
	*nongit_ok = 1;
	return NULL;
	}
	die("Not a git repository");
	}
	} while (cwd[--offset] != '/');
	}

	inside_git_dir = 0;
	if (!work_tree_env)
	inside_work_tree = 1;
	git_work_tree_cfg = xstrndup(cwd, offset);
	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;
	}

	int git_config_perm(const char var, const char value)
	{
	if (value) {
	int i;
	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;
	i = atoi(value);
	if (i > 1)
	return i;
	}
	return git_config_bool(var, value);
	}

	int check_repository_format_version(const char var, const char value)
	{
	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 (git_work_tree_cfg)
	free(git_work_tree_cfg);
	git_work_tree_cfg = xstrdup(value);
	inside_work_tree = -1;
	}
	return 0;
	}

	int check_repository_format(void)
	{
	git_config(check_repository_format_version);
	if (GIT_REPO_VERSION < repository_format_version)
	die ("Expected git repo version <= %d, found %d",
	GIT_REPO_VERSION, repository_format_version);
	return 0;
	}

	const char *setup_git_directory(void)
	{
	const char *retval = setup_git_directory_gently(NULL);
	check_repository_format();

	/* If the work tree is not the default one, recompute prefix */
	if (inside_work_tree < 0) {
	static char buffer[PATH_MAX + 1];
	char *rel;
	if (retval && chdir(retval))
	die ("Could not jump back into original cwd");
	rel = get_relative_cwd(buffer, PATH_MAX, get_git_work_tree());
	return rel && *rel ? strcat(rel, "/") : NULL;
	}

	return retval;
	}