You may have run into a situation where the name of the makefile command conflicts with the file name under the same directory.

For example, I have below code.

B_TARGET:=testapp
clean:
  rm -f $(B_TARGET)   

I execute make clean, everything is ok. The target folder is removed as expected. However, if there is a file named clean in the directory. I will get a result when I execute the make clean command.

make: 'clean' is up to date.

To avoid this issue happen, use .PHONY command. The main function of .PHONY configuration item is to avoid the conflict between the specified command and the file with the same name under the project and to optimize the performance. .PHONY [command name] explicitly specifies a command name instead of the actual file name, so that the make [command name] command can be parsed and executed correctly. You don’t have to worry about if the same name file existing or not.

I change the code as this.

.PHONY clean
B_TARGET:=testapp
clean:
  rm -f $(B_TARGET)   

I execute make clean and the command works this time.