Basic Compiler Design

Basics of Compiler Design
Extended edition

Torben Ægidius Mogensen

DEPARTMENT OF COMPUTER SCIENCE UNIVERSITY OF COPENHAGEN

Published through c

lulu.com.
2000  2008

Torben Ægidius Mogensen

[e-mail]
Department of Computer Science University of Copenhagen Universitetsparken 1 DK-2100 Copenhagen DENMARK

Book homepage:

http://www.diku.dk/∼torbenm/Basics

First published 2000 This edition: July 25, 2008

Contents

1 Introduction
1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 What is a compiler? Interpreters . . . . . . . . . . . . . . . . . . . . . The phases of a compiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Why learn about compilers? . . . . . . . . . . . . . . . . . The structure of this book . . . . . . . . . . . . . . . . . . To the lecturer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements

1
1 2 3 4 5 6 7 8

Permission to use . . . . . . . . . . . . . . . . . . . . . . .

2 Lexical Analysis
2.1 2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . Regular expressions . . . . . . . . . . . . . . . . . . . . . . 2.2.1 2.2.2 2.3 2.4 2.5 2.6 Shorthands Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9
9 10 13 14 16 19 19 21 23 24 27 30 31 33 35 37 42 44 44

Nondeterministic nite automata . . . . . . . . . . . . . . Converting a regular expression to an NFA . . . . . . . . . 2.4.1 Optimisations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Deterministic nite automata 2.6.1 2.6.2

Converting an NFA to a DFA . . . . . . . . . . . . . . . . Solving set equations . . . . . . . . . . . . . . . . . The subset construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.7 2.8

Size versus speed 2.8.1 2.8.2

Minimisation of DFAs

Example . . . . . . .