Makefile – Check if a file exists using wildcard function

The following snippet of code can be used to check for the existence of a file from within a Makefile.

ifneq ("$(wildcard $(PATH_TO_FILE))","")
FILE_EXISTS = 1
else
FILE_EXISTS = 0
endif

Quoting from make documentation.

$(wildcard pattern)
The argument pattern is a file name pattern, typically containing
wildcard characters (as in shell file name patterns). The result of
wildcard is a space-separated list of the names of existing files
that match the pattern.

In this present case, we are not using any wildcards, but the absolute path to the file.

SCons: A software construction tool – Alternative to Make/Automake/Autoconf

SCons is an Open Source software construction tool—that is, a next-generation build tool. Think of SCons as an improved, cross-platform substitute for the classic Make utility with integrated functionality similar to autoconf/automake and compiler caches such as ccache. In short, SCons is an easier, more reliable and faster way to build software.
SCons