Organization of the New Course on
Complier Construction in Novi Sad
Vladimir Kurbalija, Mirjana Ivanović
Department of Mathematics and Informatics
University of Novi Sad
Serbia
Agenda
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Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
CC Course in Novi Sad
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One of core software courses at Computer
Science directions
7th semester CC1 (obligatory), 8th
semester CC2 (elective), for students of
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Computer Science,
Business Computer Science,
Teaching of Computer Science
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Previous CC Course
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Practical approach
Development of Pascal- compiler
Subset of Pascal language:
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data types: boolean and integer standard types, arrays and
fixed records as structured types;
basic statements: assignment statement, procedure call, if
and while statements;
Standard input/output (read and write) procedures, user
defined procedures including recursion.
The implementation:
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recursive-descent manner for syntax analysis
code generation for abstract P machine
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Previous CC Course - Exercises
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Students repeat and train practical skills gained during
lectures
Several independent tasks – small grammars
Implementation language is Modula-2
Compiler generator Coco/R
Tasks:
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Lexical and syntax analysis and some parts of semantic analysis
using Coco/R
“Hand written” parsers (LA & SA)
“Hand written” parsers with semantic analysis and rarely with
code generation or interpretation
Some algorithms on grammars (memory organisation, checking
consistency, computing first and follow sets…)
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Agenda
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Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course
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More theoretical approach on lectures
Course goes through all phases of a compiler writing
Shows the theoretical concepts underlying each phase as
well as how to implement it efficiently
Examples: MicroJava compiler in Java, target language
– subset of Java byte code
Goals of the course
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acquire the practical skills to write a simple compiler for an
imperative programming language
understand the concepts of scanning, parsing, name
management in nested scopes, and code generation.
learn to transfer the skills also to general software engineering
tasks
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course
Structure of Lectures
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Overview (1 week)
Lexical Analysis (1 week)
Syntax Analysis (2 weeks) --- TEST
Attribute Grammars (1 week)
Symbol Table (2 weeks)
Code Generation (3 weeks) --- TEST
BU Parsing (2 weeks)
Compiler Generators (1 week) --- TEST
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
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Students should acquire practical skills in
compiler writing
One (big) project divided in smaller
subtasks
Students should write a small compiler for
a Java-like language - MicroJava
The implementation language is also Java
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
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Study material:
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Teaching material (slides)
Description of the project
Specification of MicroJava language (tokens, language
grammar, semantic and context constraints)
Specification of MicroJava virtual machine (similar but
simpler than Java VM) – Memory layout and
Instruction set
Specification of object file format
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
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The project consists of three levels:
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Level 1 – implementation of a scanner and a
parser for the language MicroJava, error
handling – 3 TASKS
Level 2 - deals with symbol table handling
and type checking – 1 TASK
Level 3 - deals with code generation for the
MicroJava – 1 TASK
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
Level 1 – Task 1
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Lexical analysis
Implementation of a scanner for MicroJava
Scanner should skip blanks, end of line characters,
tabulator characters and comments
Types of errors:
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The occurrence of an invalid character (e.g., $)
A missing quote at the end of the character constant ('x)
Integer constants that are too large
Some algorithms for token recognition are explained
Given material:
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A frameworks of Scanner.java and Token.java classes
Test examples
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
Level 1 – Task 2
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Syntax analysis
Implementation of a recursive descent parser for
MicroJava
Without error handling – stop on first error
The algorithm for recursive descent parser is explained
Given material:
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A complete grammar of MicroJava
A framework of Parser.java class
Test examples – Programs in MicroJava
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
Level 1 – Task 3
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Error handling
Modification of the parser and error() method
2 kinds of algorithms:
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method with special anchors
method with general anchors
These 2 algorithms are explained in detail
Given material:
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Set of anchors
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
Level 2
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Semantic analysis
Symbol table handling and type checking
Semantic analyzer should check
 Type compatibility
 Predeclared names
 Scope
Students should implement Obj.java, Struct.java, Scope.java and
Tab.java classes and modify parser
The functionality of these classes is explained
Given material:
 Frameworks of Obj.java, Struct.java, Scope.java and Tab.java
classes
 Context conditions in the grammar
 Test examples
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Current CC Course – Exercises
Level 3
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Code generation
Generate code for the MicroJava Virtual Machine (stack machine)
MicroJava Virtual Machine and its instruction set (57 instructions)
are described in detail
Students should implement Code.java, Item.java and Label.java
classes and modify parser
Given material:
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Full implementation of MicroJava VM
Decoder.java class for viewing generated code
Frameworks of Code.java, Item.java and Label.java classes
Test examples
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Agenda
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Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Assessment by students in Novi Sad
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Questionnaire - students opinion
52 students, 34 filled questionnaire
26 questions
For every question grade 1 to 5
Meaning of answers:
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1 – “I do not agree at all”
5 – “I agree completely”
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Agenda



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

Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Questionnaire - General
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The organization of the course was good
1
2
3
4
5
1
1
2
14
16
AVERAGE: 4.26
The possibility of passing the exam using colloquiums and tests is
useful
1
2
3
4
5
2
2
2
9
19
AVERAGE: 4.21
Type and difficulty of tasks are correct
1
2
3
4
5
1
2
14
12
5
AVERAGE: 3.53
The amount of material is good
1
2
3
4
5
0
0
7
12
15
AVERAGE: 4.24
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Questionnaire - General
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Lectures and exercises were good synchronized
1
2
3
4
5
0
0
8
9
17
AVERAGE: 4.26
Teaching material is good
1
2
3
4
5
1
4
15
9
5
AVERAGE: 3.38
The quality of course is good
1
2
3
4
5
0
0
8
18
8
AVERAGE: 4.00
Course is useful
1
2
3
4
5
0
2
7
13
12
AVERAGE: 4.03
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Questionnaire - Lectures
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Lectures were good prepared
1
2
3
4
5
0
1
2
12
19
Teaching style is good
1
2
3
4
5
1
0
4
14
15
I have learned enough during lectures
1
2
3
4
5
1
2
19
10
2
Lecturer was willing to give additional answers
1
2
3
4
5
0
0
3
9
21
The speed of presentation was adequate
1
2
3
4
5
0
3
9
12
10
Generally, I am satisfied with the lectures
1
2
3
4
5
0
1
6
16
10
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
AVERAGE: 4.44
AVERAGE: 4.24
AVERAGE: 3.29
AVERAGE: 4.55
AVERAGE: 3.85
AVERAGE: 4.06
Questionnaire – Exercises
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Exercises were good prepared
1
2
3
4
0
0
4
8
Teaching style of assistant is good
1
2
3
4
0
1
3
8
Assistant was willing to give additional answers
1
2
3
4
0
0
0
5
I have learned enough during exercises
1
2
3
4
0
0
9
13
The speed of presentation was adequate
1
2
3
4
0
0
5
14
The difficulty of tasks was adequate
1
2
3
4
0
1
10
11
Generally, I am satisfied with the exercises
1
2
3
4
0
0
4
11
V. Kurbalija, M. Ivanović
5
22
AVERAGE: 4.53
5
22
AVERAGE: 4.50
5
29
AVERAGE: 4.85
5
12
AVERAGE: 4.09
5
15
AVERAGE: 4.29
5
11
AVERAGE: 3.97
5
19
AVERAGE: 4.44
Organization of the New Course
on CC in Novi Sad
Questionnaire - Effort
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How many times did you miss lectures?
<3
3-7
>7
24
9
1
How many times did you miss exercises?
<3
3-7
>7
23
10
1
Did you need additional consultations?
YES
NO
7
27
By your own opinion, how many hours per week should be spent
preparing for this course?
AVERAGE: 5.66
How many hours per week did you spent preparing for this
course?
AVERAGE: 4.05
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Exam results
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52 students, 41 passed the exam
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38 in January
1 in April
2 in June
Grade distribution (6-10)
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6 – 7 students
7 – 14 students
8 – 16 students
9 – 2 students (+oral exam)
10 – 1 student (+oral exam)
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Agenda
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Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
JCCC - Material
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Novi Sad
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CC1 obligatory, CC2 elective
CC1 – use Teaching material of prof. Mössenböck,
Linz
CC2
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More theoretical, Automata theory, Formal languages theory
Other parsing methods (LR, LALR)
Detailed presentation of code generation
Different techniques of code optimization
Exercises and practical work – Real-world (more serious
project)
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
JCCC - Material
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Belgrad
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CC1 obligatory, CC2 elective
CC1
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CC2
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Partially use teaching material of prof. Mössenböck, Linz,
+ more theory,
extended version of microJava with object inheritance
Similar to Novi Sad
.doc file
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
JCCC - Material
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Possibilities to prepare common material
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Belgrad is more ambitious then Novi Sad
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Novi Sad
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Will use Linz material, completely for CC1
We are willing to prepare presentations for CC2 topics
But also seems that we have not appropriate motivation
Open Question: Writing book
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Dragan want to prepare his own material and slides
But he has not time and appropriate motivation for that
We have a lot of draft materials
Motivation? – project, publishing, …
Problem: CC2 is elective, we do not expect students
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Agenda
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Previous CC Course
Current CC Course
Assessment by students in Novi Sad
Questionnaire and Exam results
JCCC – Material
Conclusion
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Conclusion – Novi Sad Approach
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Advantages of new course:
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Concepts of compiler construction are shown on formal way
Modern and object-oriented language is used (Java and Java
byte code)
Most of students autonomously write important parts of compiler
Better students are able to write (almost) whole compiler
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The exam can be passed during the semester –
continual assessment
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Some students complain that there is not enough
literature on Serbian (enough motivation for book?)
V. Kurbalija, M. Ivanović
Organization of the New Course
on CC in Novi Sad
Thank you for your attention