it: works

This commit is contained in:
2026-03-24 18:51:30 +01:00
parent f50b8c64c6
commit c6537f2117
9 changed files with 201 additions and 23 deletions

2
.gitignore vendored
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@@ -1 +1,3 @@
/target /target
Cargo.lock

7
Cargo.lock generated
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@@ -1,7 +0,0 @@
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 4
[[package]]
name = "const-macros"
version = "0.1.0"

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@@ -9,10 +9,8 @@ repository = "https://git.javalsai.tuxcord.net/rust/const-macros"
keywords = ["compile", "const", "macro"] keywords = ["compile", "const", "macro"]
categories = ["development-tools::procedural-macro-helpers"] categories = ["development-tools::procedural-macro-helpers"]
[lib]
proc-macro = true
[dependencies] [dependencies]
const-macros-proc = { path = "./const-macros-proc" }
[lints.clippy] [lints.clippy]
cargo = { level = "warn", priority = -1 } cargo = { level = "warn", priority = -1 }

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assets/DATA1 Normal file
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This is just a bunch of bytes that will hash to a known sequence and I can test for validity

BIN
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const-macros-proc/.gitignore vendored Normal file
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/target

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[package]
name = "const-macros-proc"
version = "0.1.0"
edition = "2024"
[lib]
proc-macro = true
[dependencies]
magic = "0.16"
sha2 = "0.10"

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@@ -0,0 +1,126 @@
#![feature(proc_macro_value)]
use std::{fs::File, io::Read};
use proc_macro::{Delimiter, Group, Literal, Punct, TokenStream, TokenTree};
use sha2::Digest;
fn read_path_literal(input: TokenStream) -> String {
println!("{input:?}");
let mut input_iter = input.into_iter();
let path_token = input_iter.next().expect("expected a path");
assert!(input_iter.next().is_none(), "only expected one argument");
let path_literal = match path_token {
TokenTree::Group(path_group) => {
let mut path_stream = path_group.stream().into_iter();
let path_literal = path_stream.next().expect("expected a str literal");
assert!(path_stream.next().is_none(), "expected a str literal");
let TokenTree::Literal(path_literal) = path_literal else {
panic!("expected a str literal");
};
path_literal
}
TokenTree::Literal(path_literal) => path_literal,
_ => panic!("expected a str literal"),
};
// eprintln!("{path_literal:?}");
path_literal.str_value().expect("expected a str literal")
}
fn extend_grouped(
ts: &mut TokenStream,
delim: Delimiter,
items: impl Iterator<Item = TokenStream>,
) {
let mut comma_ts = TokenStream::new();
comma_ts.extend(std::iter::once(TokenTree::Punct(Punct::new(
',',
proc_macro::Spacing::Alone,
))));
let mut tuple_content = TokenStream::new();
tuple_content.extend(items.flat_map(|token| [token, comma_ts.clone()]));
ts.extend(std::iter::once(TokenTree::Group(Group::new(
delim,
tuple_content,
))));
}
fn extend_array(ts: &mut TokenStream, array: &[u8]) {
extend_grouped(
ts,
Delimiter::Bracket,
array.iter().map(|&b| {
let mut ts = TokenStream::new();
ts.extend(std::iter::once(TokenTree::Literal(Literal::u8_unsuffixed(
b,
))));
ts
}),
);
}
fn extend_asset_tuple(ts: &mut TokenStream, buf: &[u8], mime: &str, sha256sum: [u8; 32]) {
extend_grouped(
ts,
Delimiter::Parenthesis,
[
{
let mut ts = TokenStream::new();
ts.extend(std::iter::once(TokenTree::Punct(Punct::new(
'&',
proc_macro::Spacing::Joint,
))));
extend_array(&mut ts, buf);
ts
},
{
let mut ts = TokenStream::new();
ts.extend(std::iter::once(Literal::string(mime)));
ts
},
{
let mut ts = TokenStream::new();
extend_array(&mut ts, &sha256sum);
ts
},
]
.into_iter(),
);
}
fn get_mime(buf: &[u8]) -> String {
let cookie =
magic::Cookie::open(magic::cookie::Flags::MIME).expect("failure opening mime cookie");
let cookie = cookie
.load(&magic::cookie::DatabasePaths::default())
.expect("failure loading magic db");
cookie.buffer(buf).expect("error getting file mime")
}
fn get_sha256sum(buf: &[u8]) -> [u8; 32] {
sha2::Sha256::digest(buf)
.as_slice()
.try_into()
.expect("failed to sha256sum file")
}
#[proc_macro]
#[allow(clippy::missing_panics_doc)]
pub fn include_asset(input: TokenStream) -> TokenStream {
let path = read_path_literal(input);
let mut buf = Vec::new();
File::open(path)
.expect("couldn't open file")
.read_to_end(&mut buf)
.expect("error reading file");
let mut ts = TokenStream::new();
extend_asset_tuple(&mut ts, &buf, &get_mime(&buf), get_sha256sum(&buf));
ts
}

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@@ -1,15 +1,61 @@
// #[must_use] // So hand working with [`TokenStream`] might be a bad idea BUT I partially made this crate to
// pub const fn add(left: u64, right: u64) -> u64 { // learn about [`proc_macro`] so I'm not gonna use [`quote`] or [`syn`]
// left + right
// }
// #[cfg(test)] pub mod file {
// mod tests { pub type IncludeAssetMacroTy = (&'static [u8], &'static str, [u8; 32]);
// use super::*;
// #[test] pub struct FileAsset {
// fn it_works() { pub bytes: &'static [u8],
// let result = add(2, 2); pub mime: &'static str,
// assert_eq!(result, 4); pub shasum: [u8; 32],
// } }
// }
impl FileAsset {
#[must_use]
pub const fn from_tuple(tuple: IncludeAssetMacroTy) -> Self {
Self {
bytes: tuple.0,
mime: tuple.1,
shasum: tuple.2,
}
}
}
impl From<IncludeAssetMacroTy> for FileAsset {
fn from(value: (&'static [u8], &'static str, [u8; 32])) -> Self {
Self::from_tuple(value)
}
}
#[macro_export]
macro_rules! include_asset {
($path:literal) => {
$crate::file::FileAsset::from_tuple($crate::file::_include_asset!($path))
};
}
pub use include_asset;
pub use const_macros_proc::include_asset as _include_asset;
#[cfg(test)]
pub mod test {
#[test]
fn works() {
const ASSET1: super::FileAsset = super::include_asset!("assets/DATA1");
const ASSET2: super::FileAsset = super::include_asset!("assets/DATA2");
assert_eq!(ASSET1.bytes, b"This is just a bunch of bytes that will hash to a known sequence and I can test for validity\n");
assert_eq!(ASSET1.mime, "text/plain; charset=us-ascii");
assert_eq!(
ASSET1.shasum,
[
0x4f, 0x72, 0xae, 0x5a, 0x7e, 0x2d, 0x70, 0xfe, 0xc4, 0x13, 0xaf, 0x0e, 0x29,
0x8f, 0x1b, 0x7a, 0x7c, 0x1d, 0x8d, 0x9c, 0xaf, 0x4f, 0xd6, 0x24, 0x46, 0x0d,
0x2f, 0xe2, 0xd8, 0x1b, 0x83, 0x28,
]
);
assert_eq!(ASSET2.mime, "image/png; charset=binary");
}
}
}