CCIR

A C Compiler In Rust

About The Project

A Compiler translating C code (coherent to the C11 standard) into x86-64 bit assembly. Follows the cdecl calling convention. Grammar documentation follows Backus–Naur form.

Supported Features

• Unary Operators
  • Arithmetic Negation (-)
  • Logical Negation (!)
  • Bitwise Complement (~)
• Arithmetic Binary Operators
  • Addition (+)
  • Subtraction (-)
  • Multiplication (*)
  • Division (/)
  • Modulo (%)
  • Logical And (&&)
  • Logical Or (||)
  • Bitwise And (&)
  • Bitwise Or (|)
  • Left Shift (<<)
  • Right Shift (>>)
  • Xor (^)
• Relational Binary Operators
  • Equality (==)
  • Inequality (!=)
  • Comparison (<, >, <=, >=)
• Local Variables
  • Assignment
  • Declaration
• Global Variables
  • Implementation consistent with position-independent execution
  • Calculates constant arithmetic expressions at compile time
• Conditionals
  • Ternary Expressions
  • If Statements
  • If-Else Statements
• Compound Statements
• Variable Scoping
• Variable Shadowing
• Loops
  • While
  • Do-While
  • For
• Functions and Function Calls
• Validation to reject programs inconsistent with the C11 standard for all features listed above

Planned Features

• Support for types beyond ints
• Pointers
• Additional optimization layers

Architecture

CCIR follows a three step architecture:

• Lexing: Reads a .c file and converts the contents into a token stack
• Parsing: Executes semantic analysis to convert the token stack into an abstract syntax tree
• Code Generation: Traverses AST to produce x86 assembly

Known Issues

• MacOS does not natively support compilation of x86 assembly. If you wish to convert the generated .s file into an executable, please install Rosetta. See here.
• Requires int functions have a return statement, inconsistent with C11's specification that int functions without a return statement should automatically return 0.
• r10 and r11 not caller saved
• rbx not callee saved

Local Copy

You may run this compiler locally by following these steps:

1. Clone the repo

   git clone https://github.com/KyleleeSea/ccir

2. cargo build

3. Assemble and produce executable for desired .c file

   cargo run (path)

4. Run the executable

   ./out

The above assumes the following:

1. Installation of rust. If you do not have rust, please see: Rust installation guide.
2. Installation of gcc to convert assembly into an executable.

External Sources

• Nora Sandler
• Adam Ferrari