Compilers: Principles and Practice

1.5 Phases of a Compiler

Most of the modern compilers have the following phases:

• Pre-processing: Usually, this phase is implemented as a macro processor, with its own macro language. It provides for file inclusion, conditional compilation control of segments of the source code, definition of literals, “pragma” commands to the compiler, etc.
• Lexical analysis: (Scanner) – checks for correct use of the input character set, identifies language atoms and tags them as the type of atom, e.g. NUMBER, IDENTIFIER, OPERATION.
• Syntax analysis: (Parser) – processes output of the Scanner, detects syntactic constructs and types of statements, generates a parse tree.
• Semantic analysis: (Mapper) – processes the parse trees, detects the “meaning” of statements ...