Using a macro
-------------
To use a macro in a makefile, type "$(MacroName)" where MacroName is the
name of a defined macro. You can use braces {} and parentheses () to

MAKE expands macros at various times depending on where they appear in
the makefile:

  o  Nested macros are expanded when the outer macro is invoked.

  o  Macros in rules and directives are expanded when MAKE first looks at
     the makefile.

  o  Macros in commands are expanded when the command is executed.