1. 根目录:
2. tools
3. perf
4. util
5. abspath.c

#include "cache.h"

static const char *get_pwd_cwd(void)
{
	static char cwd[PATH_MAX + 1];
	char *pwd;
	struct stat cwd_stat, pwd_stat;
	if (getcwd(cwd, PATH_MAX) == NULL)
		return NULL;
	pwd = getenv("PWD");
	if (pwd && strcmp(pwd, cwd)) {
		stat(cwd, &cwd_stat);
		if (!stat(pwd, &pwd_stat) &&
		    pwd_stat.st_dev == cwd_stat.st_dev &&
		    pwd_stat.st_ino == cwd_stat.st_ino) {
			strlcpy(cwd, pwd, PATH_MAX);
		}
	}
	return cwd;
}

const char *make_nonrelative_path(const char *path)
{
	static char buf[PATH_MAX + 1];

	if (is_absolute_path(path)) {
		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
			die("Too long path: %.*s", 60, path);
	} else {
		const char *cwd = get_pwd_cwd();
		if (!cwd)
			die("Cannot determine the current working directory");
		if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
			die("Too long path: %.*s", 60, path);
	}
	return buf;
}