Mini-Java to LLVM IR compiler, a semester project for the compilers course at the University of Athens
make
java Main <inputFile1> <inputFile3> <inputFile3> ...
Then the LLVM IR files are generated like <inputFile3>.ll
To run the LLVM clang needs to be installed
sudo apt update && sudo apt install clang-4.0
Then compile the .ll file with
clang-4.0 -o <executable> <inputFile3>.ll
or run the experiments with
./run.sh
All the classes, variables, and methods are stored on the SumbolTable
. The SymbolTable
class inherits from the TreeMap
data structure in java and it stores objects of the Symbol
type.
Symbol
class is an abstract class that all the classes, variables, and methods inherit from. It shares the common information about these fields such as name, type, and offset.
In SymbolCLass
class are stored all the classes. There are fields for the methods and the variables of the classes. These fields are stored in a SymbolTable too.
In SumbolMethods
are stored all the methods of the class. This object also stores the variables and the arguments of the method. Finally SymbolVariable
stores the variables.
Both SYmbolClass
and SymbolMethod
implement setters and getters according to their needs.
The VirtulaTable
is a TreeMap
data structure that holds all of a class's methods.
It recursively records the parent classes' methods, and if a child class overrides one of them, the information is given to the table.
As for the visitors, there are 4 of them that implement different processes of semantic checking and for the LLVM IR generation. Firstly the parse tree is visited by the ClassDeclarationVisitor
is responsible
for adding to the SymbolTable
all
the class declarations. Then the parse tree is visited by the FillVisitor
that fills all the classes with their variables and methods and also fills the arguments and the variables of the methods too.
Then, the parse tree is visited by the CheckTypeVisitor
which performs type checking of the expressions and the statements of the methods.
Finally, the LLVM visitor parses the tree and creates LLVM IR based on the data in the Symbol and Virtual tables.