Compiler Construction

This book has emerged from the author’s lecture notes for an introductory course in compiler design at ETH Zürich. The author has been asked to justify this course for several times, since compiler design is considered a somewhat esoteric subject, practised only in a few highly specialized software houses. Because nowadays everything which does not yield immediate profits has to be justified, this book will try to explain why this subject is considered as important and relevant to computer science students in general. This book is an introduction, and not a reference book for experts. In order to be possible to explain a whole compiler in detail, and even to construct it within the limited time of a course, this book has three restrictions: The first restriction is the use of a subset of the language Oberon as the source language. This will be a small language but nevertheless contains all the truly fundamental elements of programming languages. The second restriction concerns the target computer. It will feature a regular structure and a simple instruction set. Most important is the practicality of the concepts taught. Oberon is a general-purpose, flexible and powerful language, and the target computer reflects the successful RISC-architecture in an ideal way. And finally, the third restriction lies in renouncing sophisticated techniques for code optimization. It is necessary because of the semantic gap between source languages and computer architectures on the one hand, and the desire to use the available resources as well as possible on the other.