undo using openat, it's not that much faster and adds complexity

src/unix/legacy.cc

@@ -6,13 +6,8 @@
 #endif
 #define __THROW
 
-#ifdef _LIBC
-# include <include/sys/stat.h>
-#else
-# include <sys/stat.h>
-#endif
+#include <sys/stat.h>
 #include <dirent.h>
-#include <unistd.h>
 
 #include "../DirTree.hh"
 #include "../shared/BruteForceBackend.hh"
@@ -23,42 +18,34 @@
 #endif
 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
 
-void iterateDir(Watcher &watcher, const std::shared_ptr <DirTree> tree, const char *relative, int parent_fd, std::string dirname) {
-    int open_flags = (O_RDONLY | O_CLOEXEC | O_DIRECTORY | O_NOCTTY | O_NONBLOCK | O_NOFOLLOW);
-    int new_fd = openat(parent_fd, relative, open_flags);
-
-    if (DIR *dir = fdopendir(new_fd)) {
+void iterateDir(Watcher &watcher, const std::shared_ptr <DirTree> tree, const char *dirname) {
+    if (DIR *dir = opendir(dirname)) {
         while (struct dirent *ent = (errno = 0, readdir(dir))) {
             if (ISDOT(ent->d_name)) continue;
 
-            std::string fullPath = dirname + "/" + ent->d_name;
+            std::string fullPath = dirname + std::string("/") + ent->d_name;
 
             if (watcher.mIgnore.count(fullPath) == 0) {
                 struct stat attrib;
-                fstatat(new_fd, ent->d_name, &attrib, AT_SYMLINK_NOFOLLOW);
+                stat(fullPath.c_str(), &attrib);
                 bool isDir = ent->d_type == DT_DIR;
 
                 tree->add(fullPath, CONVERT_TIME(attrib.st_mtim), isDir);
 
                 if (isDir) {
-                    iterateDir(watcher, tree, ent->d_name, new_fd, fullPath);
+                    iterateDir(watcher, tree, fullPath.c_str());
                 }
             }
         }
-    }
 
-    close(new_fd);
+        closedir(dir);
+    }
 
     if (errno) {
         throw WatcherError(strerror(errno), &watcher);
     }
 }
 
 void BruteForceBackend::readTree(Watcher &watcher, std::shared_ptr <DirTree> tree) {
-    int fd = open(watcher.mDir.c_str(), O_RDONLY);
-    if (fd) {
-        iterateDir(watcher, tree, ".", fd, watcher.mDir);
-    }
-
-    close(fd);
-}
+    return iterateDir(watcher, tree, watcher.mDir.c_str());
+}