Maintaining Recursive Targets

Targets that encompass equivalent actions in both the local directory and in subdirectories are referred to as recursive targets.

Strictly speaking, any target that calls make with its name as an argument, is recursive. However, here the term is reserved for the narrower case of targets that have both nested and local actions. Targets that have only nested actions are referred to as "nested" targets.

A makefile with recursive targets is referred to as a recursive makefile.

In the case of all, the nested dependencies are NESTED_TARGETS; the local dependencies, LOCAL_TARGETS:

NESTED_TARGETS=  debug test install 
SUBDIRS= bin lib
LOCAL_TARGETS= functions 

all: $(NESTED_TARGETS) $(LOCAL_TARGETS) 

$(NESTED_TARGETS): 
        	@ for i in $(SUBDIRS) ; \
        	do \
               echo "Current directory:  $$i" ;\
               cd $$i ; \
               $(MAKE) $@ ; \
               cd .. ; \
        	done

$(LOCAL_TARGETS):
        	@ echo "Building $@ in local directory."
       (local directory commands)

The nested make must also be recursive, unless it is at the bottom of the hierarchy. In the makefile for a leaf directory (one with no subdirectories), you build only local targets.