Building the Entire Project

Occasionally you should take a snapshot of the sources and the object files that they produce. Building an entire project involves invoking make successively in each subdirectory to build and install each module. The following example shows how to use nested make commands to build a simple project.

Assume your project is located in two different subdirectories, bin and lib, and that in both subdirectories you want make to debug, test, and install the project.

First, in the projects main, or root, directory, you put a makefile such as this:

# Root makefile for a project.  

TARGETS= debug test install 
SUBDIRS= bin lib

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

Then, in each subdirectory (in this case, bin) you place a makefile of this general form:

#Sample makefile in subdirectory
debug:
        	@echo "			Building debug target"
        	@echo
test:
        	@echo "			Building test target"
        	@echo
install:
        	@echo "			Building install target"
        	@echo

When you type make (in the base directory), you get the following output:

$ make
Current directory:  bin
         	Building debugging target

Current directory:  lib
          Building debugging target

Current directory:  bin
         	Building testing target

Current directory:  lib
         	Building testing target

Current directory:  bin
         	Building install target

Current directory:  lib
         	Building install target
$