Previously, I had incorrectly used some newer features of CMake(version 3.14). But Now I have updated this code to work with older versions of CMake too.

cmake/protobuf-config.cmake.in

@@ -99,13 +99,17 @@ function(protobuf_generate)
   foreach(_proto ${protobuf_generate_PROTOS})
     get_filename_component(_abs_file ${_proto} ABSOLUTE)
     get_filename_component(_abs_dir ${_abs_file} DIRECTORY)
-    get_filename_component(_basename ${_proto} NAME_WLE)
+
+    get_filename_component(_file_full_name ${_proto} NAME)
+    string(FIND "${_file_full_name}" "." _file_last_ext_pos REVERSE)
+    string(SUBSTRING "${_file_full_name}" 0 ${_file_last_ext_pos} _basename)
 
     set(_suitable_include_found FALSE)
     foreach(DIR ${_protobuf_include_path})
       if(NOT DIR STREQUAL "-I")
         file(RELATIVE_PATH _rel_dir ${DIR} ${_abs_dir})
-        if(NOT "${_rel_dir}" MATCHES "^\.\.[/\\].*")
+        string(FIND "${_rel_dir}" "../" _is_in_parent_folder)
+        if (NOT ${_is_in_parent_folder} EQUAL 0)
           set(_suitable_include_found TRUE)
           break()
         endif()