use stat to determine whether a directory entry is a subdirectory; d_type is not POSIX

Author: Daniel Kroening

src/util/file_util.cpp

@@ -16,6 +16,7 @@ Date: January 2012
     defined(__unix__) || \
     defined(__CYGWIN__) || \
     defined(__MACH__)
+#include <sys/stat.h>
 #include <unistd.h>
 #include <dirent.h>
 #include <cstdlib>
@@ -124,8 +125,13 @@ void delete_directory(const std::string &path)
       // Needed for Alpine Linux
       if(strcmp(ent->d_name, ".")==0 || strcmp(ent->d_name, "..")==0)
         continue;
+
       std::string sub_path=path+"/"+ent->d_name;
-      if(ent->d_type==DT_DIR)
+
+      struct stat stbuf;
+      stat(sub_path.c_str(), &stbuf);
+
+      if(S_ISDIR(stbuf.st_mode))
         delete_directory(sub_path);
       else
         remove(sub_path.c_str());