Since coding dependences in makefile are system dependent make allows to define macro names which then can be used within the description files, e.g., for adaption of filenames. A macro name has the following syntax:
The name can be any combination of alphanumeric characters starting
with an alpha character. Usually, uppercase characters are used by
convention. The value may be empty or any string up to the end of
the line. For a definition across multiple lines, the last character must be
a `
' to continue the definition in the next line. The employment
of the macro name by specifying $(<name>) in the description file
expands to the definition right from the ``='' without deleting any space
characters.
A common problem with make macro names is that some commonly used names, e.g., OBJS, and LIBRARY, are often defined in the description files in different directories with a different value.