compiler-development

name	compiler-development
description	Guide for developing Sagittarius compiler. Use this when you need to develop or optimize the compiler.

Sagittarius Scheme Compiler Development Guide

This guide provides an overview of the Sagittarius Scheme compiler architecture, optimization strategies, and best practices for development.

Compiler Architecture

The Sagittarius compiler is written in Scheme, and consists of several phases:

1. Expansion: Macro expansion and syntactic transformations
2. Optimization: Code transformations for performance improvements
3. Code Generation: Emitting C code from the optimized intermediate representation

File location

The compiler source code is located in the boot/ directory

• boot/compiler.scm - Main compiler entry point
• boot/lib/pass*.scm - Optimization passes
• boot/lib/compiler-util.scm - Utility library for compiler
• boot/lib/iform.scm - Intermediate form definitions
• boot/lib/smatch.scm - Pattern matching utilities, use include syntax to include in the compiler source files

Building the compiler

The compiler is built by the compiler from the host Sagittarius by running the command below:

For POSIX

./dist.sh precomp

For Windows

dist.bat precomp

This will generate the C code for the compiler in src/ directory. To execute the compiler you need to build the Sagittarius first by running the command below:

For POSIX

make sash -j$(nproc)

For Windows (Ninja)

ninja sash -j %NUMBER_OF_PROCESSORS%

Analysis helper

To analyze the optimisation result, you can use the compile-p* procedure to print the intermediate form of the code after each pass. The below example shows how to use it.

(import (sagittarius compiler))

(compile-p1 '((lambda (x) (+ x 1)) 5)) ;; shows result of pass1
(compile-p2 '((lambda (x) (+ x 1)) 5)) ;; shows result of pass2
(compile-p3 '((lambda (x) (+ x 1)) 5)) ;; shows result of pass3
(compile-p4 '((lambda (x) (+ x 1)) 5)) ;; shows result of pass4
(compile-p5 '((lambda (x) (+ x 1)) 5)) ;; shows result of pass5 (generated VM instructions)

You can run the script with the command below:

POSIX:

./build/sagittarius -Llib -Lsitelib -L'ext/*' -Dbuild ${file}

Windows:

.\build\sash.exe -Llib -Lsitelib -Lext/* -Dbuild %file%