VSOP Compiler

The Very Simple Object-oriented Programming (VSOP) language is a simple object-oriented language inspired from COOL, the Classroom Object-Oriented Language designed by Alex Aiken. More information is provided in the VSOP manual.

This project consists in the realization of a VSOP compiler. It has been realized under the direction of Cyril Soldani as part of the course Compilers given by Pascale Fontaine to graduate computer science students at the University of Liège during the academic year 2019-2020.

A few test files are provided in the resources/vsop/ directory.

Installation

The compiler has been developped in standard C++14, using flex, bison and LLVM version 9.0.0.

One can install these dependencies with

make install-tools

and then build the compiler executable with

make vsopc

Implementation

The project was divided into four parts.

1. The lexical analysis consists in converting the input VSOP file into a sequence of tokens.

   ./vsopc -lex resources/vsop/functional/002-hello-world.vsop

   1,1,class
   1,7,type-identifier,Main
   1,12,lbrace
   2,5,object-identifier,main
   2,9,lpar
   2,10,rpar
   2,12,colon
   2,14,int32
   2,20,lbrace
   3,9,object-identifier,print
   3,14,lpar
   3,15,string-literal,"Hello, world!\x0a"
   3,32,rpar
   3,33,semicolon
   4,9,integer-literal,0
   5,5,rbrace
   6,1,rbrace
   

2. The syntax analysis uses the tokens to generate an Abstract Syntax Tree of the input.

   ./vsopc -parse resources/vsop/functional/002-hello-world.vsop

   [Class(Main, Object, [], [
   	Method(main, [], int32, [
   		Call(self, print, ["Hello, world!\x0a"]),
   		0
   	])
   ])]
   

3. The semantic analysis performs the type and scope checking while traveling through the AST.

   ./vsopc -check resources/vsop/functional/002-hello-world.vsop

   [Class(Main, Object, [], [
   	Method(main, [], int32, [
   		Call(self:Main, print, ["Hello, world!\x0a":string]):Object,
   		0:int32
   	])
   ]:int32)]
   

4. The code generation translates the input to an LLVM intermediate representation and, finally, compiles it.

   ./vsopc resources/vsop/functional/002-hello-world.vsop
   ./resources/vsop/functional/002-hello-world

   Hello, world!
   

Some explanations about the implementation can be found in the project report as well as in the code itself, that has been documented to some extent.

Extensions

A few extensions have been added to the vanilla VSOP language, such as floating point arithmetic, top-level functions, foreign function interface, etc.

Their description is available in the project report at the section Extensions.