setup.c - jrn/git - Git at Google

 #include "cache.h"

 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)
 		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;
 }

 static int inside_git_dir = -1;

 int is_inside_git_dir(void)
 {
 	if (inside_git_dir >= 0)
 		return inside_git_dir;
 	die("BUG: is_inside_git_dir called before setup_git_directory");
 }

 static int inside_work_tree = -1;

 int is_inside_work_tree(void)
 {
 	if (inside_git_dir >= 0)
 		return inside_work_tree;
 	die("BUG: is_inside_work_tree called before setup_git_directory");
 }

 static char *gitworktree_config;

 static int git_setup_config(const char *var, const char *value)
 {
 	if (!strcmp(var, "core.worktree")) {
 		if (gitworktree_config)
 			strlcpy(gitworktree_config, value, PATH_MAX);
 		return 0;
 	}
 	return git_default_config(var, value);
 }

 const char *setup_git_directory_gently(int *nongit_ok)
 {
 	static char cwd[PATH_MAX+1];
 	char worktree[PATH_MAX+1], gitdir[PATH_MAX+1];
 	const char *gitdirenv, *gitworktree;
 	int wt_rel_gitdir = 0;

 	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 	if (!gitdirenv) {
 		int len, offset;

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

 		offset = len = strlen(cwd);
 		for (;;) {
 			if (is_git_directory(".git"))
 				break;
 			if (offset == 0) {
 				offset = -1;
 				break;
 			}
 			chdir("..");
 			while (cwd[--offset] != '/')
 				; /* do nothing */
 		}

 		if (offset >= 0) {
 			inside_work_tree = 1;
 			git_config(git_default_config);
 			if (offset == len) {
 				inside_git_dir = 0;
 				return NULL;
 			}

 			cwd[len++] = '/';
 			cwd[len] = '\0';
 			inside_git_dir = !prefixcmp(cwd + offset + 1, ".git/");
 			return cwd + offset + 1;
 		}

 		if (chdir(cwd))
 			die("Cannot come back to cwd");
 		if (!is_git_directory(".")) {
 			if (nongit_ok) {
 				*nongit_ok = 1;
 				return NULL;
 			}
 			die("Not a git repository");
 		}
 		setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
 		gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 		if (!gitdirenv)
 			die("getenv after setenv failed");
 	}

 	if (PATH_MAX - 40 < strlen(gitdirenv)) {
 		if (nongit_ok) {
 			*nongit_ok = 1;
 			return NULL;
 		}
 		die("$%s too big", GIT_DIR_ENVIRONMENT);
 	}
 	if (!is_git_directory(gitdirenv)) {
 		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");
 	if (chdir(gitdirenv)) {
 		if (nongit_ok) {
 			*nongit_ok = 1;
 			return NULL;
 		}
 		die("Cannot change directory to $%s '%s'",
 			GIT_DIR_ENVIRONMENT, gitdirenv);
 	}
 	if (!getcwd(gitdir, sizeof(gitdir)-1))
 		die("Unable to read current working directory");
 	if (chdir(cwd))
 		die("Cannot come back to cwd");

 	/*
 	 * In case there is a work tree we may change the directory,
 	 * therefore make GIT_DIR an absolute path.
 	 */
 	if (gitdirenv[0] != '/') {
 		setenv(GIT_DIR_ENVIRONMENT, gitdir, 1);
 		gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 		if (!gitdirenv)
 			die("getenv after setenv failed");
 		if (PATH_MAX - 40 < strlen(gitdirenv)) {
 			if (nongit_ok) {
 				*nongit_ok = 1;
 				return NULL;
 			}
 			die("$%s too big after expansion to absolute path",
 				GIT_DIR_ENVIRONMENT);
 		}
 	}

 	strcat(cwd, "/");
 	strcat(gitdir, "/");
 	inside_git_dir = !prefixcmp(cwd, gitdir);

 	gitworktree = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	if (!gitworktree) {
 		gitworktree_config = worktree;
 		worktree[0] = '\0';
 	}
 	git_config(git_setup_config);
 	if (!gitworktree) {
 		gitworktree_config = NULL;
 		if (worktree[0])
 			gitworktree = worktree;
 		if (gitworktree && gitworktree[0] != '/')
 			wt_rel_gitdir = 1;
 	}

 	if (wt_rel_gitdir && chdir(gitdirenv))
 		die("Cannot change directory to $%s '%s'",
 			GIT_DIR_ENVIRONMENT, gitdirenv);
 	if (gitworktree && chdir(gitworktree)) {
 		if (nongit_ok) {
 			if (wt_rel_gitdir && chdir(cwd))
 				die("Cannot come back to cwd");
 			*nongit_ok = 1;
 			return NULL;
 		}
 		if (wt_rel_gitdir)
 			die("Cannot change directory to working tree '%s'"
 				" from $%s", gitworktree, GIT_DIR_ENVIRONMENT);
 		else
 			die("Cannot change directory to working tree '%s'",
 				gitworktree);
 	}
 	if (!getcwd(worktree, sizeof(worktree)-1))
 		die("Unable to read current working directory");
 	strcat(worktree, "/");
 	inside_work_tree = !prefixcmp(cwd, worktree);

 	if (gitworktree && inside_work_tree && !prefixcmp(worktree, gitdir) &&
 	    strcmp(worktree, gitdir)) {
 		inside_git_dir = 0;
 	}

 	if (!inside_work_tree) {
 		if (chdir(cwd))
 			die("Cannot come back to cwd");
 		return NULL;
 	}

 	if (!strcmp(cwd, worktree))
 		return NULL;
 	return cwd+strlen(worktree);
 }

 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);
        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();
 	return retval;
 }
	#include "cache.h"

	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)
	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;
	}

	static int inside_git_dir = -1;

	int is_inside_git_dir(void)
	{
	if (inside_git_dir >= 0)
	return inside_git_dir;
	die("BUG: is_inside_git_dir called before setup_git_directory");
	}

	static int inside_work_tree = -1;

	int is_inside_work_tree(void)
	{
	if (inside_git_dir >= 0)
	return inside_work_tree;
	die("BUG: is_inside_work_tree called before setup_git_directory");
	}

	static char *gitworktree_config;

	static int git_setup_config(const char var, const char value)
	{
	if (!strcmp(var, "core.worktree")) {
	if (gitworktree_config)
	strlcpy(gitworktree_config, value, PATH_MAX);
	return 0;
	}
	return git_default_config(var, value);
	}

	const char setup_git_directory_gently(int nongit_ok)
	{
	static char cwd[PATH_MAX+1];
	char worktree[PATH_MAX+1], gitdir[PATH_MAX+1];
	const char gitdirenv, gitworktree;
	int wt_rel_gitdir = 0;

	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
	if (!gitdirenv) {
	int len, offset;

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

	offset = len = strlen(cwd);
	for (;;) {
	if (is_git_directory(".git"))
	break;
	if (offset == 0) {
	offset = -1;
	break;
	}
	chdir("..");
	while (cwd[--offset] != '/')
	; /* do nothing */
	}

	if (offset >= 0) {
	inside_work_tree = 1;
	git_config(git_default_config);
	if (offset == len) {
	inside_git_dir = 0;
	return NULL;
	}

	cwd[len++] = '/';
	cwd[len] = '\0';
	inside_git_dir = !prefixcmp(cwd + offset + 1, ".git/");
	return cwd + offset + 1;
	}

	if (chdir(cwd))
	die("Cannot come back to cwd");
	if (!is_git_directory(".")) {
	if (nongit_ok) {
	*nongit_ok = 1;
	return NULL;
	}
	die("Not a git repository");
	}
	setenv(GIT_DIR_ENVIRONMENT, cwd, 1);
	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
	if (!gitdirenv)
	die("getenv after setenv failed");
	}

	if (PATH_MAX - 40 < strlen(gitdirenv)) {
	if (nongit_ok) {
	*nongit_ok = 1;
	return NULL;
	}
	die("$%s too big", GIT_DIR_ENVIRONMENT);
	}
	if (!is_git_directory(gitdirenv)) {
	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");
	if (chdir(gitdirenv)) {
	if (nongit_ok) {
	*nongit_ok = 1;
	return NULL;
	}
	die("Cannot change directory to $%s '%s'",
	GIT_DIR_ENVIRONMENT, gitdirenv);
	}
	if (!getcwd(gitdir, sizeof(gitdir)-1))
	die("Unable to read current working directory");
	if (chdir(cwd))
	die("Cannot come back to cwd");

	/*
	* In case there is a work tree we may change the directory,
	* therefore make GIT_DIR an absolute path.
	*/
	if (gitdirenv[0] != '/') {
	setenv(GIT_DIR_ENVIRONMENT, gitdir, 1);
	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
	if (!gitdirenv)
	die("getenv after setenv failed");
	if (PATH_MAX - 40 < strlen(gitdirenv)) {
	if (nongit_ok) {
	*nongit_ok = 1;
	return NULL;
	}
	die("$%s too big after expansion to absolute path",
	GIT_DIR_ENVIRONMENT);
	}
	}

	strcat(cwd, "/");
	strcat(gitdir, "/");
	inside_git_dir = !prefixcmp(cwd, gitdir);

	gitworktree = getenv(GIT_WORK_TREE_ENVIRONMENT);
	if (!gitworktree) {
	gitworktree_config = worktree;
	worktree[0] = '\0';
	}
	git_config(git_setup_config);
	if (!gitworktree) {
	gitworktree_config = NULL;
	if (worktree[0])
	gitworktree = worktree;
	if (gitworktree && gitworktree[0] != '/')
	wt_rel_gitdir = 1;
	}

	if (wt_rel_gitdir && chdir(gitdirenv))
	die("Cannot change directory to $%s '%s'",
	GIT_DIR_ENVIRONMENT, gitdirenv);
	if (gitworktree && chdir(gitworktree)) {
	if (nongit_ok) {
	if (wt_rel_gitdir && chdir(cwd))
	die("Cannot come back to cwd");
	*nongit_ok = 1;
	return NULL;
	}
	if (wt_rel_gitdir)
	die("Cannot change directory to working tree '%s'"
	" from $%s", gitworktree, GIT_DIR_ENVIRONMENT);
	else
	die("Cannot change directory to working tree '%s'",
	gitworktree);
	}
	if (!getcwd(worktree, sizeof(worktree)-1))
	die("Unable to read current working directory");
	strcat(worktree, "/");
	inside_work_tree = !prefixcmp(cwd, worktree);

	if (gitworktree && inside_work_tree && !prefixcmp(worktree, gitdir) &&
	strcmp(worktree, gitdir)) {
	inside_git_dir = 0;
	}

	if (!inside_work_tree) {
	if (chdir(cwd))
	die("Cannot come back to cwd");
	return NULL;
	}

	if (!strcmp(cwd, worktree))
	return NULL;
	return cwd+strlen(worktree);
	}

	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);
	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();
	return retval;
	}