Simple C Compiler written in Python

Simple C Compiler supports a subset of C programming language. Most notably it has only integer typed variables. Nevertheless, it is a fully functional C compiler front-end for generating intermediate representation (IR) three address codes from a C source file. Furthermore, an interpreter program [1] for the three address "assembly" code is provided for all major platforms (Windows, Linux and Mac) to execute the programs with ease.

As the name hints, it is also simple to use! Only one python module needed to start using it!

This compiler implementation is also part of a blog post about designing and implementing compilers, you might wanna check it out!

Requirements

All major operating systems (Windows, Linux and Mac) should be supported.

Make sure Python 3.6 or newer interpreter is installed on your system. Then install the anytree package with pip

pip install anytree

Installation and Testing

For testing the compiler here is a simple test program that prints the 15 first odd numbers

/* 
 * Simple example source code
 * 
 * prints N odd numbers
 */

void main(void) {
    /* all variables need to be declared first */
    int i;
    int j;
    int m;
    int N;
    
    /* ...and then assigned to */
    i = 1;
    j = 1;
    m = 0-1; // syntax only supports binary operations, this is how we get -1

    N = 15; // change me to increase number of odd numbers

    while (i < N * 2 + 1) {
        j = m * j;
        if (j < 0) {
            output(i);
        } else {
            // do nothing, the syntax does not support if without else :^)
        }
        i = i + 1;
    }
}

To compile and run it, type

git clone https://github.com/Hyper5phere/simple-c-compiler.git
cd simple-c-compiler
python compiler.py input/input_simple.c --run

To see all input arguments type

python compiler.py --help

All output of the compiler is stored in the ./output folder and all the input examples can be found from ./input folder. Additionally errors are logged in the ./errors folder if --error-files input flag is used.

Possible Future Improvements

Language support for

• arrays
• recursion
• string types
• nested functions (not really C though)

References

[1] The interpreter program has been implemented by Romina Jafarian, at Computer Engineering Department of Sharif University of Technology (Tehran) in Fall 2017.