#
# Example Makefile (C) Giovanni Organtini 2007 - G.Organtini@roma1.infn.it
#
# Lines starting with # are comments
#

# The following line defines new suffixes (some suffixes are already defined)
# You can check existing rules using make -p (note that  newly defined rules
# will be appended to the output). This line is needed to inform make that we
# are going to define implicit rules for files ending in .e and .d
.SUFFIXES: .e .d

# The following line declares all, clean and mrproper to be phony rules, i.e.
# rules whose target is not the name of a file. If missing rules works fine,
# but if a file exists with the name of a rule, then it stops working
.PHONY: all clean mrproper

# Variables definition. Variable content can be updated using += operator
CC=c++
CFLAGS=-O1
CFLAGS+=-I.

# This rule describes how to generate .d files from .cpp files. .d files
# contains dependencies. The -MM flag on c++ command generates dependencies
# (ignoring system wide files). The source file is processed and the output
# passed to sed to generate a line of type:
# file.o file.d : <dependencies>
# so make knows that file.o depends on the content of file.d and that file.d
# must be regenerated if any of the dependencies changes.
.cpp.d:
	$(SHELL) -ec '$(CC) -MM $(CFLAGS) $< | sed -e "s/$*.o/& $@/g" > $@'

# This rule describe how to pass from .o to .e (executable) files
.o.e: 
	$(CC) -o $@ $<

# Implicit rule for compilation (overrides existing rule)
.cpp.o: 
	$(CC) -c $(CFLAGS) $< 

# Define the variable sources using wildcard expansion. Note that it is not
# the same of *.cpp. The latter works, but if *.cpp files are missing an error
# is generated.
sources = $(wildcard *.cpp)

# Phony rule to generate all. Since this is the first rule it is executed 
# automatically. It asks to generate all .e files from .cpp files.
all: $(patsubst %.cpp, %.e, $(sources))

# include dependencies list. If .d files are missing they are generated
# using rule above.
include $(sources:.cpp=.d)

# clean phony rule
clean:
	rm -f *.o
	rm -f *.e

# more cleaning
mrproper: clean
	rm -f *.d
	rm -f *~