build: fixed submodule check

CMakeLists.txt

@@ -175,19 +175,21 @@ endif()
 if(NOT MANUAL_SUBMODULES)
   find_package(Git)
   if(GIT_FOUND)
+    function (check_submodule relative_path)
+      execute_process(COMMAND git -C ${relative_path} rev-parse "HEAD"  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} OUTPUT_VARIABLE localHead)
+      execute_process(COMMAND git rev-parse "HEAD:${relative_path}"     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} OUTPUT_VARIABLE checkedHead)
+      string(COMPARE EQUAL "${localHead}" "${checkedHead}" upToDate)
+      if (upToDate)
+        message(STATUS "Submodule '${relative_path}' is up-to-date")
+      else()
+        message(FATAL_ERROR "Submodule '${relative_path}' is not up-to-date. Please update with\ngit submodule update --init --force ${relative_path}\nor run cmake with -DMANUAL_SUBMODULES=1")
+      endif()
+    endfunction ()
+    
     message(STATUS "Checking submodules")
-    execute_process(COMMAND bash -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/external/miniupnp && git rev-parse HEAD" OUTPUT_VARIABLE miniupnpLocalHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    execute_process(COMMAND bash -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/external/unbound && git rev-parse HEAD" OUTPUT_VARIABLE unboundLocalHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    execute_process(COMMAND bash -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/external/rapidjson && git rev-parse HEAD" OUTPUT_VARIABLE rapidjsonLocalHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    execute_process(COMMAND bash -c "git ls-tree HEAD ${CMAKE_CURRENT_SOURCE_DIR}/external/miniupnp | awk '{print $3}'" OUTPUT_VARIABLE miniupnpCheckedHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    execute_process(COMMAND bash -c "git ls-tree HEAD ${CMAKE_CURRENT_SOURCE_DIR}/external/unbound | awk '{print $3}'" OUTPUT_VARIABLE unboundCheckedHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    execute_process(COMMAND bash -c "git ls-tree HEAD ${CMAKE_CURRENT_SOURCE_DIR}/external/rapidjson | awk '{print $3}'" OUTPUT_VARIABLE rapidjsonCheckedHead WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
-    string(COMPARE EQUAL "${miniupnpLocalHead}" "${miniupnpCheckedHead}" miniupnpUpToDate)
-    string(COMPARE EQUAL "${unboundLocalHead}" "${unboundCheckedHead}" unboundUpToDate)
-    string(COMPARE EQUAL "${rapidjsonLocalHead}" "${rapidjsonCheckedHead}" rapidjsonUpToDate)
-    if (NOT miniupnpUpToDate OR NOT unboundUpToDate OR NOT rapidjsonUpToDate)
-      message(FATAL_ERROR "Submodules not up to date. Please update with git submodule init && git submodule update, or run cmake with -DMANUAL_SUBMODULES=1")
-    endif()
+    check_submodule(external/miniupnp)
+    check_submodule(external/unbound)
+    check_submodule(external/rapidjson)
   endif()
 endif()