What is macro call? Explain.
Macro call: While a macro name is used along with a set of actual parameters this is replaced through a code generated from its body. Such code is termed as macro expansion. There are two kinds of expansions:
a. Lexical expansion
b. Semantic expansion
Lexical expansion: This means a replacement of character string by the other string during program generation. This is generally used to replace occurrences of formal parameters through corresponding actual ones.
Semantic Expansion: This implies generation of instructions build to the requirements of exact usage. This is characterized by the fact that various uses of a macro can lead to codes that differ in the number, opcodes and sequence of instructions.