Concepts of Programming Languages

26 Chapter 1 Preliminaries

Source

program

Lexical

analyzer

Syntax

analyzer

Intermediate

code generator

and semantic

analyzer

Optimization

(optional)

Symbol

table

Code

generator

Computer

Results

Input data

Machine

language

Intermediate

code

Parse trees

Lexical units

Figure 1.3

The compilation process

The intermediate code generator produces a program in a different lan-

guage, at an intermediate level between the source program and the final out-

put of the compiler: the machine language program.^4 Intermediate languages

sometimes look very much like assembly languages, and in fact, sometimes are

actual assembly languages. In other cases, the intermediate code is at a level

4. Note that the words program and code are often used interchangeably.