The Irken Compiler

Irken is a statically-typed, simplified variant of Scheme. Or... a lisp-like variant of ML, depending on your point of view. If you're not familiar with either family of languages, Irken is a strongly typed, compiled language with a lisp-like syntax extensible with macros. It uses type inference along with a powerful type system to give you the speed of a compiled language with high-level data types and a higher degree of safety than languages like C/C++.

• Why: to host massively scalable systems without using threads.
• How: compile using continuation-passing style to avoid using the C stack.
• Blog: http://alien.nightmare.com/
• GitHub: https://github.com/samrushing/irken-compiler/

News:

20180829: Merged the FFI branch in.

This includes a lot of work:

• new FFI system that supports all three backends.
• genffi uses a full C parser to generate an interface file.
• ASN.1 codec
• Lots of crypto support code (x509, hmac, hkdf, rsa-pss, libsodium, libdecaf, ...).
• constant-time modular bignum arithmetic for crypto, based on Thomas Pornin's i31 code.
• DFA lexer and regex library based on derivatives.
• Earley parser.
• TLS 1.3 implementation.
• websockets/rfc6455.
• HTTP/2 server.

20170329: Merged the bytecode backend and VM.

This has been tested on four platforms:

• amd64 osx-10
• amd64 freebsd-11
• amd64 linux-ubuntu-xenial
• aarch64 linux-debian rpi-3

Introduction/Tutorial:

http://dark.nightmare.com/rushing/irken/irken/lang.html

The best way to get familiar with the language is to read the source code in the 'self' directory, and browse over the files in "tests".

Bootstrap:

Irken is written in itself, so you need to bootstrap it using a pre-compiled bytecode image.

Just run make bootstrap:

$ make bootstrap

The default compiler is 'clang', to use gcc:

$ CC=gcc make bootstrap

Which does the following:

1. use self/bootstrap.byc to generate and compile self/compile.c.
2. this binary will be used to recompile the compiler.
3. that binary will recompile the compiler again.
4. the output from steps 2 and 3 are compared, they should be identical.

Note: It is not possible to compile with optimization off, because this disables the tail call optimization that Irken relies on - otherwise the stack will overflow instantly.

Installation:

$ python util/install.py

This will install support files into /usr/local/lib/irken and the binary as /usr/local/bin/irken. If you want to use a different prefix (like /usr), edit util/install.py and self/context.scm, and rebuild self/compile before installing:

$ self/compile self/compile.scm

Usage:

Here's a sample - create a random ASCII maze:

$ irken demo/maze/maze.scm
$ demo/maze/maze 20 10 -ascii

 +--------+--------+-----+-----------+-----------------+-----+
 |        |        |     |           |                 |     |
 |  +---  |  ---+  +--+  |  +--------+  |  +-----+---  |  |  |
 |  |     |     |     |  |  |           |  |     |     |  |  |
 |  |  ---+---  +---  |  |  +--+  +---  +--+  |  +--+  |  +--+
 |  |           |     |  |     |  |     |     |     |  |     |
 |  +-----+--+--+  +--+  +---  |  |  ---+  ---+---  |  +---  |
 |  |     |  |     |  |  |        |     |     |     |  |     |
 |  |  |  |  |  +--+  |  +-----+--+-----+---  |  +--+  |  ---+
 |     |  |  |  |  |  |        |        |     |  |     |     |
 +--+--+  |  |  |  |  +------  |  ---+  |  +--+  |  ---+  |  |
 |  |     |  |        |        |     |     |     |        |  |
 |  |  |  |  +--+---  |  +---  +-----+-----+  ---+---  ---+  |
 |     |  |     |        |     |           |              |  |
 +-----+  +---  |  +-----+  +--+  ------+  +------  |     |  |
 |        |        |     |  |           |           |     |  |
 |  ---+--+--+-----+  |  |  |  +-----+  +-----------+  +--+  |
 |     |     |        |  |  |  |     |              |  |     |
 |  |  +---  |  |  ---+  |  +--+  |  +------------  |  |  ---+
 |  |        |  |     |           |                 |  |     |
 +--+--------+--+-----+-----------+-----------------+--+-----+

You might want to try looking at and understanding the 'verbose' output from the compiler, using a relatively small example:

$ irken -v tests/t_while.scm

Irken will use the CC and CFLAGS environment variables when compiling the C output. You may try out another compiler like this:

$ CC="gcc" CFLAGS="-std=c99 -O2 -I." irken ...

LLVM Backend:

To use the LLVM backend, add the -llvm arg:

$ self/compile demo/parse/synlight.scm -llvm
$ demo/parse/synlight demo/parse/irken-lex.sg tests/tak20.scm

Bytecode Backend:

Irken now comes with a VM and bytecode backend. The VM runs about 3-4X slower than compiled code, but can speed up development because the edit-compile-run loop skips calling the C compiler. Turnaround while working on the compiler (on my machine) is ~5s.

To use the bytecode/VM:

$ irken myfile.scm -b
$ irkvm myfile.byc

You can also run the compiler in the VM:

$ irkvm self/compile.byc myfile.scm -b
$ irkvm myfile.byc

ARMv8

I was able to get Irken running on a Raspberry Pi 3, using the pi64 distribution. Good news: the llvm readcyclecounter intrinsic seems to work just fine on ARM. Bad news: user mode doesn't have permission to read it. I was able to get everything working by commenting all rdtsc-related code in include/{header1.c,gc1.c}. My understanding is that reading this register is a Bad Idea on the ARM, so I may conditionalize it in the source.

32-bit platforms

Once upon a time Irken compiled and ran on 32-bit x86. With the SSA-style rewrite that relies on tail call elimination, this appears to no longer be possible. Neither gcc or llvm seem to support full tail call elimination on this platform. Even manually tagging all functions with 'fastcc' (by compiling to llvm asm and editing the result) does not fix the problem. If you really need to run Irken on a 32-bit platform, know that the VM seems to work just fine. [that said, many of the library facilities assume 64-bit integers are available]