gnu make - Makefile to support 2 executables -

i trying update makefile support building binary of project, , binary of unit tests.

my directory structure following

|-code/ |--|--src/ |--|--inc/ | |-tests/ |--|--src/ |--|--inc/ 

my makefile compiles binary code well, having issues test. test folder contains unit test tests classes in code/src/. have file main.cpp in code/src/ contains main() function, , file, called test.cpp in tests/src contains own main() function.

this led me complicated makefile:

cc = g++ flags = -g -c -wall  includedir = -icode/inc -itests/inc builddir = build  sourcedir = code/src sources = $(wildcard $(addsuffix /*.cpp,$(sourcedir))) temp_obj = $(sources:%.cpp=%.o) not_dir = $(notdir $(temp_obj)) objects = $(addprefix $(builddir)/, $(not_dir))  test_dir = tests/src test_sources = $(wildcard $(addsuffix /*.cpp,$(test_dir))) test_temp_obj = $(test_sources:%.cpp=%.o) test_not_dir = $(notdir $(test_temp_obj)) test_objects = $(addprefix $(builddir)/, $(test_not_dir))  executable = client test_executable = testunit  all: $(builddir) $(builddir)/$(executable) $(builddir)/$(test_executable)  $(builddir):     mkdir -p $@  $(builddir)/$(executable): $(objects)     $(cc) $^ -o $@  $(builddir)/%.o : code/src/%.cpp     $(cc) $(flags) $< $(includedir) -o $@  $(builddir)/$(test_executable): $(objects) $(test_objects)     @rm -f $(builddir)/main.o     $(cc) $^ -o $@  $(builddir)/%.o : tests/src/%.cpp     $(cc) $(flags) $< $(includedir) -o $@  clean:     rm -rf $(builddir) 

it fails error:

g++: error: build/main.o: no such file or directory make: *** [build/testunit] error 1 

which because have line:

@rm -f $(builddir)/main.o 

but otherwise error (there main in main.cpp , test.cpp in code/src/ , tests/code/ respectively):

/tests/src/test.cpp:7: multiple definition of `main' code/src/main.cpp:6: first defined here collect2: error: ld returned 1 exit status 

there lot of duplication in makefile, , love more succinct achieves purpose of building 2 binaries 2 folders, although code shared.

any please appreciated. thank much!

there number of problems makefile.

first, there no rule build test object files, such test.o. rule building objects requires source in code/src/; don't know how far enough see linker error.

let's change object rule static pattern rule:

$(objects) : $(builddir)/%.o : code/src/%.cpp     $(cc) $(flags) $< $(includedir) -o $@ 

then can add additional rule test objects:

$(test_objects) : $(builddir)/%.o : tests/src/%.cpp     $(cc) $(flags) $< $(includedir) -o $@ 

(never mind redundancy now-- have working first.)

now should see linker error in rule:

$(builddir)/$(test_executable): $(objects) $(test_objects)     ... 

in list of prerequisites 2 files, main.o , test.o fighting on gets define main(). want test.o, main.o must go:

$(builddir)/$(test_executable): $(filter-out build/main.o,$(objects)) $(test_objects)     ... 

try , tell result. once it's working can slim down.