Makefile snippets

snippets.mk

# Check if a library exists
define lib_exists
echo "int main(){}" | g++ -x c++ -Wl,--no-as-needed -l$(1) -
endef

# Update a git submodule
define update_external
if git submodule status external/$(1) | egrep -q '^[-]|^[+]'; then\
    git submodule update --init  external/$(1);\
fi
endef