Test whether a directory exists inside a makefile

Question

In his answer @Grundlefleck explains how to check whether a directory exists or not. I tried some to use this inside a makefile as follow:

foo.b         


        

Answer 1

I use the following to detect if a file or a directory exists and act upon it :

$(if $(filter expected,$(wildcard *)), the expected file exists)

With your request :

.PHONY: ~/Dropbox

~/Dropbox:
    echo "Dir exists"

foo.bak: foo.bar | $(if $(filter ~/Dropbox,$(wildcard ~/*)), the expected file exists)

Which can further be simplify :

foo.bak: foo.bar | $(wildcard ~/Dropbox)