How to compile C and CPP files together?

Hello，I am a fresh man of Cmake,I want use Cmake instead of Makefile to compile a project which includes c and cpp files. The Makefile in the project as following:

...

App/Enclave_u.o: App/Enclave_u.c                        ###use `GCC Compiler` to compile C file and generate .o file
	@$(CC) $(App_C_Flags) -c $< -o $
	@echo "CC   <=  $<"

App/%.o: App/%.cpp                                      ###use `G++ Compiler` to compile CPP files and generate .o file
	@$(CXX) $(App_Cpp_Flags) -c $< -o $@
	@echo "CXX  <=  $<"

$(App_Name): App/Enclave_u.o $(App_Cpp_Objects)         ###link
	@$(CXX) $^ -o $@ $(App_Link_Flags)
	@echo "LINK =>  $
...

the code above first use GCC Compiler to compile C file and generate .o file,then it use G++ Compiler to compile CPP files,finally it links with .o files which generate above.

so How to use Cmake to achieve the above operations? thank you very much!