Makefile to demonstrate make dependencies using the "touch" command.

makefile

######################################################################
# Default target (must be first target in file)
.PHONY : all
all : dog

######################################################################
# Constants
SHELL   = /bin/sh
CC      = g++
CXX     = g++
LINK    = ${CXX} ${LDFLAGS}

# Default value is blank, unless set on commmand line
CFLAGS    = 
LDFLAGS   = 

vpath %.h /usr/include

# Delete all built-in suffixes, then make our own list
.SUFFIXES:
.SUFFIXES: .cpp .o .h 

######################################################################
# clean
define doClean
  rm -f *.o *.exe 
endef

.PHONY : clean
clean :
  ${doClean}

######################################################################
# dog
dogCpp := dog.cpp dogSays.cpp

dogObj := $(patsubst %.cpp,%.o,${dogCpp}) 

dog.exe : ${dogObj} 
	${LINK} $^ -o $@ 

.PHONY : dog
dog : dog.exe
	@echo
	$<
	@echo

######################################################################
# Generic build rules

%.o : %.cpp
	${CXX} ${CFLAGS} -c $<

# Dependency specifications created automatically by Depend.groovy
include depSpecs.mk

######################################################################
# Fail-safe dependency injection:  all source files depend on all include files.
# If any include file changes, touch each corresponding source file to force
# recompilation of any dependent targets (i.e. objects & executables).
#
# $(wildcard *.cpp) : $(wildcard *.h)
# 	touch $@