README.md

C0 Compiler

• About
  • Commands Accepted
• Development toolchain
• Executing
• Contributors

About

A basic compiler that reads C0 language ¹ code and generates a code in Assembly for MIPS architecture.

Commands accepted

The following commands and block of commands are accepted by this simple C0 compiler:

• Basic types (int, bool) and constants such as true, false and integer numbers.
• String type
• Comments in line or block multiline: // or /* multiline comment */
• Arithmetic expressions: +, -, *, / and %
• Variable declarations, and variable simple attributions of value: variable_name = expression
• Comparison operators: ==, !=, <, <=, >, >=
• Conditional executors:

  if(expression)
    //single line instruction or instruction block
  

  if(expression)
    //single line instruction or instruction block
  else
    //single line instruction or instruction block
  

• Instruction blocks:

  {
    //multiple lines of instructions
  }
  

• Cycles for or while:

  while(expression)
    //single line instruction or instruction block
  

• Function definitions with argument parameters and possible return of a value
• Functions for IO of integers: scan_int(), print_int()
• Printing function for string: print_str()
• Flux control: break and continue
• Logical operators with short-circuit evaluation: !, && and ||

Development toolchain

• Haskell
• Cabal for building the application.
• Alex for generating lexical analysers.
• Happy for parsing generation.

Executing

Run the commands:

• cabal build
• cabal run < tests/input.c0

Examples

File saved as input.c0 into /tests directory:

int factorial(int n) {
  if (n == 0) 
    return 1;
  return n * factorial(n-1);
}

int main() {
  print_int(factorial(scan_int()));
}

Contributors

• carlahnr
• Rui Santos

Footnotes

1. A simplified version of C language created for teaching programming created by University Carnegie Mellon. See C0 Reference Guide. ↩