makefile with diff targets

.SUFFIXES:

headers := $(wildcard include/*.h)
source := $(wildcard **/*.cpp)
objects := ${source:.cpp=.o}
diffs := ${source:.cpp=.diff}

#

run: $(objects) diff.summary
        g++ -o run $(objects)

%.o : %.cpp
        g++ -c $< -o $@

#

diff.summary : $(diffs)
        cat $(diffs) | tee $@

%.diff : %.cpp
        @diff -u $< <(clang-format $<) > $@ || true

#

clean :
        rm -rf run diff.summary $(objects) $(diffs)