FLAGS = -Wall -Wextra -fno-strict-aliasing -fno-common -Wp,-D_FORTIFY_SOURCE=2 -O3 -ggdb3 -fPIC
LTO   = -flto
CC    = gcc
AR    = ar
RANLIB = ranlib

# Uncomment EITHER of the following line to make things work
#LTO   =
#AR    = gcc-ar
#RANLIB = :

all: main

clean:
	rm -f lib.c main.c lib.o main.o libtest.a main

lib.c:
	echo 'int answer(void) { return 42; }' > $@

main.c:
	echo 'int answer(void); int main(void) { return answer(); }' > $@

main: lib.c main.c
	$(CC) $(LTO) $(FLAGS) -c lib.c
	$(CC) $(LTO) $(FLAGS) -c main.c
	$(AR) cru libtest.a lib.o
	$(RANLIB) libtest.a
	$(CC) $(LTO) $(FLAGS) -o main main.o libtest.a

.PHONY: clean all