OOP Language Compiler with Lex and Bison

Overview

This project is a compiler for a simple object-oriented programming (OOP) language, developed using Lex and Bison. The compiler handles lexical analysis, syntax parsing, and semantic checking for class declarations, method calls, variable assignments, and basic control flow constructs.

The main goal is to demonstrate the creation of a basic compiler that can process an OOP language, including parsing class declarations, methods, variables, and basic expressions.

Features

• Lexical analysis using Flex for tokenizing input.
• Syntax analysis using Bison to construct the syntax tree.
• Semantic checks for type matching and scope validation.
• Support for basic control flow (if, while, for), method calls, and object instantiation.

Files in Repository

• project.l: Lex specification file for lexical analysis.
• project.y: Bison grammar file for syntax analysis.
• Makefile: Build script to compile the project.
• input.txt: Example input file containing a test OOP program.
• output.txt: The compiler's output file after processing the input.
• project.tab.c: Bison-generated C file for the parser.
• project.tab.h: Bison-generated header file.
• lex.yy.c: Flex-generated C file for the lexer.

Directory Structure

Flex-Bison-Compiler/
|
├── Licence
├── Makefile
├── README.md
├── error.cpp
├── error.h
├── errors.txt
├── input.txt
├── lex.yy.c
├── myParser.exe
├── output.txt
├── parser_log.txt
├── project.l
├── project.tab.c
├── project.tab.h
├── project.y
├── Παραδοχές.txt
│   

How to Build and Run

Prerequisites

Ensure you have the following installed:

• Flex: Fast lexical analyzer generator
• Bison: Parser generator
• GCC: GNU Compiler Collection

Steps to Build

1. Clone the repository:

   git clone https://github.com/your-repository-name.git
   cd your-repository-name

2. Compile the project using the Makefile:

   make

This command will:

• Generate project.tab.c and project.tab.h from the Bison grammar file.
• Generate lex.yy.c from the Lex file.
• Compile all generated C files and link them into an executable myParser.

Running the Compiler

To run the compiler on a test program:

./myParser input.txt

This will process the input.txt file and generate an output in output.txt.

Example Input

public class Test {
    public void main(int x, int y) {
        x = 0;
    }
}

Example Output

Collected Assignments:
1) Variable x assigned with value 0

Input Program:
   1  | public class Test {
   2  |     public void main(int x, int y) {
   3  |         x = 0;
   4  |     }
   5  | }

Program is syntactically correct.

Error Handling

• Created files error.cpp and error.h to handle errors from both lex and bison files
• The compiler will print error messages with the line number if it encounters any syntax or semantic errors.
• Example error message:

  Error at line 6: Unexpected character '!'
  

License

This project is licensed under the MIT License. See the LICENSE file for more details.