Defining Macros on the Command Line
Macros can be defined on the Make command line. For example:
would start up Make and define the macro CFLAGS with the value “–ms”. Macros defined on the command line take precedence over macros of the same name defined in the makefile.
If a command-line macro contains spaces, it must be enclosed in double quotes as in:
make “CFLAGS=-ms -z -p”