lcc

This is a recovered copy of the source code of a C-subset compiler I worked on a couple years ago, cleaned up and tidied a bit. Outputs single pass SSA code with additional bookkeeping for function declarations.

I had completed it at the time somewhat, but the final copy outputted pretty bad NASM code, with some very basic optimizations like dead code elimination for if-conditionals with pure constant statements. This current copy is an incomplete one, which outputs SSA pseudocode instead of assembly, which I hope to complete again, and advance beyond.

I plan on making this a modular multipass optimizing compiler that outputs fairly optimized nasm code. I plan on writing an opt module that handles propagations in multiple passes, along with dead code elimination and (maybe) loop unrolling. I also plan on writing a basic assembly emitter toasm to emit nasm code.

For now this has no symbol checking. Errors are also printed to stdout.

Build

To build, do make.

Test

To test, feed any file from test.c to lcc.

bin/lcc < test/test.c

Roadmap

1. Add symbol checking.

2. Add multipass opt module:

   Hypothetically this should work like this:

       lcc < sample_file.c | opt | opt ...
   

   where each iteration propagates different constants and variables.

3. Add backend translator toasm to NASM.

4. Chain all modules through a simple driver app.