What is the simplest code to get the top-level directory part of a makefile variable? Example:BUILD_DIR = dir/subdir/.../sub-a-dub-dirdistclean:        rm -rf <some code which evaluates to dir from $(BUILD_DIR)>PS: I don't mean $(dir $(dir $(BUILD_DIR))), but something which gets the first directory part of any variable value.
Get top-level directory from makefile variable
make
Do you mean the first component of the directory? If so, turn the path into a list of components, then extract the first component. I assume you're using GNU make, and you're not doing something insane like expect file names with whitespace to go through unscathed. Don't try this with an absolute path.override BUILD_DIR = dir/subdir/.../sub-a-dub-dirdistclean:        rm -rf $(firstword $(subst /, ,$(BUILD_DIR)))I make BUILD_DIR override whatever the user might have passed on the command line, to avoid someone accidentally passing it and having something unintended deleted.