Question

In a makefile, I build all my .o files in a build directory:

program: class1.o class2.o class3.o
    g++ $(BUILDDIR)class1.o $(BUILDDIR)class2.o $(BUILDDIR)class3.o -o $@

It would be cool to generate $(BUILDDIR)class1.o $(BUILDDIR)class2.o $(BUILDDIR)class3.o from the dependencies list…

I know that $^ would give me the list of all dependencies, separated by spaces, but I can’t deal with the sub-directory.

Is it possible ?

And if I have program: class1.o class2.o class3.o configure, can I exclude configure from the list ?

Thank you 🙂

Edit: Michael’s solutions works well, but doing that, make does not find the dependencies and has to build everything everytime… Isn’t there a simpler way, when making implicit rules like program: class1.o class2.o class3.o, to tell it to put the binaries in a build directory ?

Answer 1

Off the top of my head

g++ $(addprefix $(BUILDDIR), $^) -o $@

should do it.

The Make manual has a list of these functions in section 8.3.