53 lines
1 KiB
Markdown
53 lines
1 KiB
Markdown
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title = 'Os Devlog: Lisp Compiler'
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date = 2024-09-08T12:00:00+02:00
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categories = ["os"]
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tags = ["lowlevel", "lisp", "compiler"]
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summary = "LISP :3"
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draft = true
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## Introduction
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In my previous article I wrote about my [os](https://forgejo.vanten-s.com/vanten-s/os).
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In this article I will explore the [compiler I have made for the system](https://forgejo.vanten-s.com/vanten-s/lisp-8bit).
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## Goals for the compiler
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Goals are important for getting stuff done. With this compiler I want to:
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- Implement a simple LISP language
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- Compile to a format that my OS supports
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- Functions
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- Variables
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- Loops
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- If statements
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- First-class functions
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## AST
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For the program
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```lisp
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(+ 1 (+
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a b ))
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```
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The AST looks like this:
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```text
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/ \
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+ / \
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1 / \
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/ \ NIL
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+ / \
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a / \
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b NIL
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```
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## Compilation
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My lisp-implementation is heavily stack-based, and only uses registers when using instructions that need them.
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For example, a + function could compiler to this:
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```asm
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pop eax
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pop ebx
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add eax, ebx
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push eax
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```
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