ttsvetanov/swy

swy
A static language for homogeneous meta-programming

Introduction

This is my personal experimental educational research compiler which originally powered my bachelor's thesis: "An Imperative Programming Language with Compile-time Homogeneous Meta-Programming". It's built on LLVM and ANTLR and features my own language for homogeneous meta-programming where we can do compile-time evaluations with the same language we use for run-time programming. Internally the compiler uses an LLVM ORC-JIT for evaluating expressions at compile-time as well as generating new code based upon those evaluations.

To be honest, I always wanted to invent my own programming language (like most enthusiastic developers), so I took the chance when I thought about a possible topic for a bachelor's thesis while keeping a special research in mind.

The overall project was developed in ~40 days, currently it's far away from being perfect, however I tried to keep the standards in software design high.

Software Architecture

The compilation pipeline slightly differs from existing languages for allowing homogeneous meta-programming, the compiler uses a flat unstructured representation of AST nodes which makes deep cloning easy:

Design patterns

The compiler itself uses a lot of C++ meta programming, for instance there are traversel functions which can up-cast AST nodes to their real type (this is a modern visitor replacement):

ASTNode* node = ...;

traverseNodeExpecting(node, pred::hasChildren(), [&](auto promoted) {
  // Static AST predicates: ^^^^^^^^^^^^^^^^^^^ we expect a node with children

  // `promoted` has the type of the node, the lambda is instantiated multiple times
  return std::count(promoted->children.begin(), promoted->children.end());
});

Requirements

Installation Instructions

Windows

Requirements:

CMake
Java 8

Build LLVM and run the CMake GUI on the compiler source

Select the LLVM cmake config

Linux

Requirements:

CMake
Java 8

Due to the usage of the ANTLR framework we have to build LLVM with RTTI support enabled:

git clone http://llvm.org/git/llvm.git
cd llvm
git checkout release_39

mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=~/llvm-rtti \
         -DCMAKE_BUILD_TYPE=Release \
         -DLLVM_ENABLE_ASSERTIONS=OFF \
         -DLLVM_TARGETS_TO_BUILD="X86" \
         -DLLVM_ENABLE_RTTI=ON

make -j8
make install

Build the compiler:

mkdir build
cd build

cmake -DLLVM_DIR=~/llvm-rtti/lib/cmake/llvm \
      -DANTLR_USE_PATH_JAVA=ON -DUSE_PCH=OFF ..

make -j8

ttsvetanov / swy