# Look for a needed .h and .c file for a given module
	# This is used for the legacy FFI
	fun add_extern(mmodule: MModule)
	do
		var file = mmodule.filepath
		file = file.strip_extension(".nit")
		var tryfile = file + ".nit.h"
		if tryfile.file_exists then
			self.declare_once("#include \"{tryfile.basename}\"")
			self.compiler.files_to_copy.add(tryfile)
		end
		tryfile = file + "_nit.h"
		if tryfile.file_exists then
			self.declare_once("#include \"{tryfile.basename}\"")
			self.compiler.files_to_copy.add(tryfile)
		end

		if self.compiler.seen_extern.has(file) then return
		self.compiler.seen_extern.add(file)
		tryfile = file + ".nit.c"
		if not tryfile.file_exists then
			tryfile = file + "_nit.c"
			if not tryfile.file_exists then return
		end
		var f = new ExternCFile(tryfile.basename, "")
		self.compiler.extern_bodies.add(f)
		self.compiler.files_to_copy.add(tryfile)
	end