Macros provide a convenient way to replace one string with another in the description file. The text is automatically replaced each time NMAKE32 is run. This feature makes it easy to change text throughout the description file without having to edit every line that uses the text. Some common uses of macros are:

• To create a standard description file for several projects. The macro represents the names of commands. These names are defined when you run NMAKE32. When a different project is started, changing the macro changes the names NMAKE32 uses throughout the description file.

• To control the options that NMAKE32 passes to the compiler, assembler, or linker. When using a macro to specify the options, options can be quickly changed throughout the description file in one easy step.

• Defining groups of files in a project, such as the .OBJ files required to build an executable or a library.

A macro can be defined:

• On the command line

• As a predefined macro

• Through inheritance from environment variables

• In the TOOLS.INI or BUILTINS.MAK (if defined)

• In a description file