Compiler won't recognize *.hxx files

I am using some tools to generate C++ code for my project and the extension is .hxx. This works fine outside of the legato build system. However, when I add the .hxx source to the .cdef file, I get a compilation error saying “error: Unrecognized file name extension on source code file […] .hxx”

Is it possible to support other formats than .cpp / .h or I am out of luck?

.hxx is a header file of C++ which is no need to added into .cdef file.

sources in cdef:
Contains a list of source code files.
If C or C++ code, one source file must implement a COMPONENT_INIT function. The framework will automatically call that function at start-up.

init.c // This one implements the COMPONENT_INIT