/C-compiler

⚙️ C => x86. Compiler built in JS

Primary LanguageJavaScript

C-compiler

A bare-bones C compiler built in Javascript (~1000 lines)
Compiles into GNU assembly and ran independently on a virtual machine
Note that NodeJS v16 is needed along with xxoriso, GNU binutils, and QEMU

compile and run with ./compile.bash example.c Output assembly will in a file called code.s

Special Features:

This compiler is slightly different than all others, please read this

  • Returns statements must have brackets like a function call
    • Unless it is a void function
  • All mathematics equations must be placed in eq(...) and are evaluated left-to-right in an accumulative manner
    • Do not use parenthesis in these equations
    • For multiplication use x
    • For & use AND
  • Functions can be called a pointer (ex. int *) and do not need to be casted to a special type
    • An unlimited number of parameters is also supported
    • Do not worry about editor warnings
  • Pointers can be operated on without casts
  • The address of an array can be maniuplated like a pointer
  • There is no strict type checking
  • There are 3 types:
    • char: 1 byte
    • short: 2 bytes
    • int: 4 bytes

See notes.txt for things that are not currently working

More Notes:

  • All assembly runs standalone
  • This means I have built my own tty driver, keyboard handler etc.
  • This also means that many functions may not work properly
  • However, you can always make your own drivers
  • Feel free to look into BODY/libs or here
    • A sample tty driver written in C (for my compiler) I have been working on can be found in CCompiler/old tests/vga.c

Changelog - 2022

April 24

  • First stage of the compiler is up and running
  • Definition of variables, pointers, buffers, etc.

April 27

  • Functions with return types and parameters
  • stdout is fully functional

April 29

  • Pointers fixed
  • Pointer type arrays
  • Math can now be expressed with eq(...)

April 30

  • Labels and goto statements

May 5

  • While statements included
  • Strings no longer need to be passed with &

May 8

  • Pointer typed parameters
  • String literals
  • If and If else statements
  • Unlimited amount of indirect memory references per line

May 12

  • Casting
  • Calling functions from pointers

May 14

  • Pointer casting
  • String literals with spaces in them
  • sizeof
  • static allocation alloc(type, size)

July 6

  • Fixed pointer casting
  • Fixed crash on divide/remainder
  • Allows indirect values on variable init

July 7

  • & now supported in eq() as AND
  • Early returns
  • Indirect array modification
  • New precompiler/preprocessor
  • #define replacement macros
  • Comments with //

July 9

  • Reworked normal replacement macros
  • Macros with parameters
  • While loops with pointers

July 13

  • Fixed un-initialized arrays
  • Added stdin: char getc(void) void gets(pointer) and void geti(pointer)

July 17

  • Replaced old stdio library with new one (finally)
  • Added importing system files
  • char_ln string_ln int_ln print a new line afterwards
  • <stdio.s> and <strings.s>
  • Fixed pointer arrays
  • Re-asigning a pointer with a string