mcc

A mini (Subset of) C compiler written in C#, just for fun (and learning purposes)

About

Based on this blog series by Nora Sandler: Write a Compiler

Successfully passes all test cases (including some additional) provided by the same Author.

Note: Only the following subset of C is currently supported:

• int Datatype
• Unary Operators ('-', '~', '!')
• Binary Operators ('+', '-', '*', '/', '%', '<', '>', '&', '|', '^', "&&", "||", "==", "!=", "<=", ">=", "<<", ">>")
• Local and Global variables (only of type int)
• Conditionals (if/else, Ternary "?:")
• Compound Statements / Code Blocks / Scopes
• Loops (for, do, while)
• Function Declaration, Definition and Calling (returning int value, optional arguments)

Not (yet) implemented:

• Optionally from Part5:

  • Compound Assignment Operators ("+=", "-=", "/=", "*=", "%=", "<<=", ">>=", "&=", "|=", "^=")
  • Comma Operator (e1, e2)
  • Increment/Decrement Operators (Prefix and postfix ++, Prefix and postfix --)

• Optimizations (Constant folding, Constant propagation, Dead code elimination, etc.)

Other notes:

• Compiles source into x86_64 or Arm64 assembly (depends on OS arch)
• Generated *.s files get assembled using gcc
• There is an option to interpret a source file (for supported subset)
• Running Tests removes output files
• Uses Calling Conventions for x86_64 (System V ABI for Linux 64-Bit and others, or MS x64 ABI for Windows 64-Bit) and Calling Conventions for Arm64

Tested on

• Windows 10 64-Bit (Visual Studio 2022, .Net 6.0, gcc installed via cygwin 3.3.5)
• Debian 11 (Bullseye) via WSL (.Net 6.0, gcc 10.2.1)
• Raspberry Pi OS 64 Bit (Debian 11 Bullseye) on Raspberry Pi 3B+ (.Net 6.0, gcc 10.2.1)
• Bytecode Backend