Added simple cmake file (#8)

CMakeLists.txt

@@ -0,0 +1,26 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(jbpf-protobuf)
+include(ExternalProject)
+
+add_definitions(-DPB_FIELD_32BIT)
+
+execute_process(
+    COMMAND bash ./init_submodules.sh
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+    RESULT_VARIABLE result
+    OUTPUT_VARIABLE output
+    ERROR_VARIABLE error
+)
+
+add_subdirectory(jbpf)
+
+if (NOT PROJECT_IS_TOP_LEVEL)
+  ######## Export header files for other projects ############
+  set(JBPF_IO_HEADER_FILES ${JBPF_IO_HEADER_FILES} PARENT_SCOPE)
+  set(JBPF_MEM_MGMT_HEADER_FILES ${JBPF_MEM_MGMT_HEADER_FILES} PARENT_SCOPE)
+  set(JBPF_LIB_HEADER_FILES ${JBPF_LIB_HEADER_FILES} PARENT_SCOPE)
+  set(JBPF_CK_HEADER_FILES ${JBPF_CK_INCLUDES} PARENT_SCOPE)
+  set(JBPF_COMMON_HEADERS ${JBPF_COMMON_HEADERS} PARENT_SCOPE)
+  set(JBPF_LCM_IPC_HEADER_FILES ${JBPF_LCM_IPC_HEADER_FILES} PARENT_SCOPE)
+endif()