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Compiler Construction


Admission requirements

This is a practical-intensive course, which involves lots of low-level systems programming. Mastering all this is also highly rewarding. Students are assumed to have taken courses in (advanced) programming, computer architecture/organization, computer networks, and operating systems at a BSc level.


Computer programs in a higher programming language cannot be executed by a computer until they have been translated into lower-level code. In many cases this is done by a compiler.

In this course we learn how compilers convert source code into assembly code in several steps. We study the theory behind compilers with a keen eye on the practical aspects of building a compiler, and apply this in a series of assignments where we construct a C compiler, which outputs x86-64 code, executable on all modern Intel and AMD processors.

Topics covered during the lectures relate to the process of constructing a compiler, e.g.: lexical analysis, syntax analysis, semantic analysis, intermediate code generation, code generation, and code optimization.

Course Objectives

Gain insight into the functionality of the different phases of the compilation process, and how these phases are related to each other. Become familiar with the different steps in the construction of a compiler and the problems that arise with them


You will find the timetables for all courses and degree programmes of Leiden University in the tool MyTimetable (login). Any teaching activities that you have sucessfully registered for in MyStudyMap will automatically be displayed in MyTimeTable. Any timetables that you add manually, will be saved and automatically displayed the next time you sign in.

MyTimetable allows you to integrate your timetable with your calendar apps such as Outlook, Google Calendar, Apple Calendar and other calendar apps on your smartphone. Any timetable changes will be automatically synced with your calendar. If you wish, you can also receive an email notification of the change. You can turn notifications on in ‘Settings’ (after login).

For more information, watch the video or go the the 'help-page' in MyTimetable. Please note: Joint Degree students Leiden/Delft have to merge their two different timetables into one. This video explains how to do this.

Mode of Instruction

The course is composed of two components:
1. Lectures given by the instructor, to setup course format, assignments, and to teach key topics in compiler construction.
2. Self-study Lab Assignments. Students are expected to work on the lab assignments autonomously, outside of the lectures. We also set up Lab Class, every week, after the lectures. In these labs, students ask questions and get practical help by teaching assistants. Please note, this is a hands-on course, where the lab constitutes a large part of the final grade.

For the practicals of this course, we implement a (subset-of-)C compiler, which outputs x86-64 instructions.

A regular compiler has 4 main stages to go from code to machine-understandable instructions: 1. Lexical analyzer stage 2. Syntaxtree generator stage 3. Intermediate code generator stage 4. Machine-code emitter stage

There are 6 practical assignments, each one about designing compiler functionality to treat various language features and compiler components and optimizations. Students will build each next stage on top of their previous stage implementations.

A base framework will be published to write your implementation in, featuring: - Basic code to start from. - Unit tests to verify implementation correctness. - An automated grading system.
The assignment will be in modern C++ (C++14).


The final grade of this course is composed of a large practical assignment (80%), in-class activity (20%), and various bonuses which add on top of the regular activities.

The bonuses are programming assignments, expanding the compiler designed in the main practical assignment. (up to 1p extra)

Assessment method

The final grade of this course is composed of a large practical assignment (80%), in-class activity (20%), and various bonuses which add on top of the regular activities. To pass the course, students have to get an average grade higher than or equal to 6 (six) for the assignments. All the assignments have to be submitted.

The in-class activity is composed of several quizzes. Participation in the quizzes is not mandatory but highly recommended.

Course load

Total hours of study: 168 hrs.
Practical work: 100 hrs
Lectures & Tutoring: 20 hrs
Self-tuition: 48 hrs

Reading list

Alfred V. Aho, Monica S. Lam, Ravi Sethi, Jeffrey D. Ullman, Compilers: Principles, Techniques, and Tools, second edition, Pearson New International Edition, 2013, ISBN 9781292024349.


From the academic year 2022-2023 on every student has to register for courses with the new enrollment tool MyStudyMap. There are two registration periods per year: registration for the fall semester opens in July and registration for the spring semester opens in December. Please see this page for more information.

Please note that it is compulsory to both preregister and confirm your participation for every exam and retake. Not being registered for a course means that you are not allowed to participate in the final exam of the course. Confirming your exam participation is possible until ten days before the exam.
Extensive FAQ's on MyStudymap can be found here.


Teacher of the course, Alexandru Uta
Onderwijscoördinator Informatica, Education coordinator LIACS bachelors


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