COMPILER DESIGN

Detailed explanation-1: -Macros allow you to write commonly used PL/I code in a way that hides implementation details and the data that is manipulated and exposes only the operations. In contrast with a generalized subroutine, macros allow generation of only the code that is needed for each individual use.

Detailed explanation-2: -The C preprocessor is a macro processor that is used automatically by the C compiler to transform your program before actual compilation. It is called a macro processor because it allows you to define macros, which are brief abbreviations for longer constructs.