`5a3fe2c70832`

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crates/evm-coder/src/custom_signature.rs7.4 KiBsource history
1//! # A module for custom signature support.2//!3//! ## Overview4//! This module allows you to create arbitrary signatures for types and functions in compile time.5//!6//! ### Type signatures7//! To create the desired type signature, you need to create your own trait with the `SIGNATURE` constant.8//! Then in the implementation, for the required type, use the macro [`make_signature`]9//! #### Example10//! ```11//! use std::str::from_utf8;12//! use evm_coder::make_signature;13//! use evm_coder::custom_signature::{14//! 	SignatureUnit,15//! 	SIGNATURE_SIZE_LIMIT16//! };17//!18//! // Create trait for our signature19//! trait SoliditySignature {20//!		const SIGNATURE: SignatureUnit;21//!22//!		fn name() -> &'static str {23//!			from_utf8(&Self::SIGNATURE.data[..Self::SIGNATURE.len]).expect("bad utf-8")24//!		}25//!	}26//!27//! // Make signatures for some types28//!	impl SoliditySignature for u8 {29//!		make_signature!(new fixed("uint8"));30//!	}31//!	impl SoliditySignature for u32 {32//!		make_signature!(new fixed("uint32"));33//!	}34//!	impl<T: SoliditySignature> SoliditySignature for Vec<T> {35//!		make_signature!(new nameof(T) fixed("[]"));36//!	}37//!	impl<A: SoliditySignature, B: SoliditySignature> SoliditySignature for (A, B) {38//!		make_signature!(new fixed("(") nameof(A) fixed(",") nameof(B) fixed(")"));39//!	}40//!	impl<A: SoliditySignature> SoliditySignature for (A,) {41//!		make_signature!(new fixed("(") nameof(A) fixed(",") shift_left(1) fixed(")"));42//!	}43//!44//! assert_eq!(u8::name(), "uint8");45//! assert_eq!(<Vec<u8>>::name(), "uint8[]");46//! assert_eq!(<(u32, u8)>::name(), "(uint32,uint8)");47//! ```48//!49//! ### Function signatures50//! To create a function signature, the macro [`make_signature`] is also used, which accepts51//! settings for the function format [`SignaturePreferences`] and function parameters [`SignatureUnit`]52//! #### Example53//! ```54//! use core::str::from_utf8;55//! use evm_coder::{56//!		make_signature,57//!		custom_signature::{58//!			SIGNATURE_SIZE_LIMIT, SignatureUnit, SignaturePreferences, FunctionSignature,59//!		},60//!	};61//! // Trait for our signature62//! trait SoliditySignature {63//!		const SIGNATURE: SignatureUnit;64//!65//!		fn name() -> &'static str {66//!			from_utf8(&Self::SIGNATURE.data[..Self::SIGNATURE.len]).expect("bad utf-8")67//!		}68//!	}69//!70//! // Make signatures for some types71//!	impl SoliditySignature for u8 {72//!		make_signature!(new fixed("uint8"));73//!	}74//!	impl<T: SoliditySignature> SoliditySignature for Vec<T> {75//!		make_signature!(new nameof(T) fixed("[]"));76//!	}77//! ```7879/// The maximum length of the signature.80pub const SIGNATURE_SIZE_LIMIT: usize = 256;8182/// Storage for the signature or its elements.83#[derive(Debug)]84pub struct SignatureUnit {85	/// Signature data.86	pub data: [u8; SIGNATURE_SIZE_LIMIT],87	/// The actual size of the data.88	pub len: usize,89}9091impl SignatureUnit {92	/// Create a signature from `&str'.93	pub const fn new(name: &'static str) -> SignatureUnit {94		let mut signature = [0_u8; SIGNATURE_SIZE_LIMIT];95		let name = name.as_bytes();96		let name_len = name.len();97		let mut dst_offset = 0;98		crate::make_signature!(@copy(name, signature, name_len, dst_offset));99		SignatureUnit {100			data: signature,101			len: name_len,102		}103	}104	/// String conversion105	pub fn as_str(&self) -> Option<&str> {106		core::str::from_utf8(&self.data[0..self.len]).ok()107	}108}109110/// ### Macro to create signatures of types and functions.111///112/// Format for creating a type of signature:113/// ```ignore114/// make_signature!(new fixed("uint8")); // Simple type115/// make_signature!(new fixed("(") nameof(u8) fixed(",") nameof(u8) fixed(")")); // Composite type116/// ```117#[macro_export]118macro_rules! make_signature {119	(new $($tt:tt)*) => {120		($crate::custom_signature::SignatureUnit {121			data: {122				let mut out = [0u8; $crate::custom_signature::SIGNATURE_SIZE_LIMIT];123				let mut dst_offset = 0;124				$crate::make_signature!(@data(out, dst_offset); $($tt)*);125				out126			},127			len: {0 + $crate::make_signature!(@size; $($tt)*)},128		})129	};130131	(@size;) => {132		0133	};134	(@size; fixed($expr:expr) $($tt:tt)*) => {135		$expr.len() + $crate::make_signature!(@size; $($tt)*)136	};137	(@size; nameof($expr:ty) $($tt:tt)*) => {138		<$expr>::SIGNATURE.len + $crate::make_signature!(@size; $($tt)*)139	};140	(@size; shift_left($expr:expr) $($tt:tt)*) => {141		$crate::make_signature!(@size; $($tt)*) - $expr142	};143144	(@data($dst:ident, $dst_offset:ident);) => {};145	(@data($dst:ident, $dst_offset:ident); fixed($expr:expr) $($tt:tt)*) => {146		{147			let data = $expr.as_bytes();148			let data_len = data.len();149			$crate::make_signature!(@copy(data, $dst, data_len, $dst_offset));150		}151		$crate::make_signature!(@data($dst, $dst_offset); $($tt)*)152	};153	(@data($dst:ident, $dst_offset:ident); nameof($expr:ty) $($tt:tt)*) => {154		{155			$crate::make_signature!(@copy(&<$expr>::SIGNATURE.data, $dst, <$expr>::SIGNATURE.len, $dst_offset));156		}157		$crate::make_signature!(@data($dst, $dst_offset); $($tt)*)158	};159	(@data($dst:ident, $dst_offset:ident); shift_left($expr:expr) $($tt:tt)*) => {160		$dst_offset -= $expr;161		$crate::make_signature!(@data($dst, $dst_offset); $($tt)*)162	};163164	(@copy($src:expr, $dst:expr, $src_len:expr, $dst_offset:ident)) => {165		{166			let mut src_offset = 0;167			let src_len: usize = $src_len;168			while src_offset < src_len {169				$dst[$dst_offset] = $src[src_offset];170				$dst_offset += 1;171				src_offset += 1;172			}173		}174	}175}176177#[cfg(test)]178mod test {179	use core::str::from_utf8;180181	use super::{SIGNATURE_SIZE_LIMIT, SignatureUnit};182183	trait Name {184		const SIGNATURE: SignatureUnit;185186		fn name() -> &'static str {187			from_utf8(&Self::SIGNATURE.data[..Self::SIGNATURE.len]).expect("bad utf-8")188		}189	}190191	impl Name for u8 {192		const SIGNATURE: SignatureUnit = make_signature!(new fixed("uint8"));193	}194	impl Name for u32 {195		const SIGNATURE: SignatureUnit = make_signature!(new fixed("uint32"));196	}197	impl<T: Name> Name for Vec<T> {198		const SIGNATURE: SignatureUnit = make_signature!(new nameof(T) fixed("[]"));199	}200	impl<A: Name, B: Name> Name for (A, B) {201		const SIGNATURE: SignatureUnit =202			make_signature!(new fixed("(") nameof(A) fixed(",") nameof(B) fixed(")"));203	}204	impl<A: Name> Name for (A,) {205		const SIGNATURE: SignatureUnit =206			make_signature!(new fixed("(") nameof(A) fixed(",") shift_left(1) fixed(")"));207	}208209	struct MaxSize();210	impl Name for MaxSize {211		const SIGNATURE: SignatureUnit = SignatureUnit {212			data: [b'!'; SIGNATURE_SIZE_LIMIT],213			len: SIGNATURE_SIZE_LIMIT,214		};215	}216217	#[test]218	fn simple() {219		assert_eq!(u8::name(), "uint8");220		assert_eq!(u32::name(), "uint32");221	}222223	#[test]224	fn vector_of_simple() {225		assert_eq!(<Vec<u8>>::name(), "uint8[]");226		assert_eq!(<Vec<u32>>::name(), "uint32[]");227	}228229	#[test]230	fn vector_of_vector() {231		assert_eq!(<Vec<Vec<u8>>>::name(), "uint8[][]");232	}233234	#[test]235	fn tuple_of_simple() {236		assert_eq!(<(u32, u8)>::name(), "(uint32,uint8)");237	}238239	#[test]240	fn tuple_of_tuple() {241		assert_eq!(242			<((u32, u8), (u8, u32))>::name(),243			"((uint32,uint8),(uint8,uint32))"244		);245	}246247	#[test]248	fn vector_of_tuple() {249		assert_eq!(<Vec<(u32, u8)>>::name(), "(uint32,uint8)[]");250	}251252	#[test]253	fn tuple_of_vector() {254		assert_eq!(<(Vec<u32>, u8)>::name(), "(uint32[],uint8)");255	}256257	#[test]258	fn complex() {259		assert_eq!(260			<(Vec<u32>, (u32, Vec<u8>))>::name(),261			"(uint32[],(uint32,uint8[]))"262		);263	}264265	#[test]266	fn max_size() {267		assert_eq!(<MaxSize>::name(), "!".repeat(SIGNATURE_SIZE_LIMIT));268	}269270	#[test]271	fn shift() {272		assert_eq!(<(u32,)>::name(), "(uint32)");273	}274275	#[test]276	fn over_max_size() {277		let t = trybuild::TestCases::new();278		t.compile_fail("tests/build_failed/custom_signature_over_max_size.rs");279	}280}