From 52384868828f1e85a34062f4490f0272b53c420b Mon Sep 17 00:00:00 2001
From: Emilia Hane <elsaemiliaevahane@gmail.com>
Date: Wed, 22 Jan 2025 21:11:59 +0100
Subject: [PATCH] feat(no_std): Add `no_std` support for
 `reth-ethereum-engine-primitives` (#13931)

---
 crates/ethereum/engine-primitives/Cargo.toml     | 16 +++++++++++++++-
 crates/ethereum/engine-primitives/src/lib.rs     |  7 +++++--
 crates/ethereum/engine-primitives/src/payload.rs |  5 +++--
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/crates/ethereum/engine-primitives/Cargo.toml b/crates/ethereum/engine-primitives/Cargo.toml
index f019f6e5f..09b1ac6af 100644
--- a/crates/ethereum/engine-primitives/Cargo.toml
+++ b/crates/ethereum/engine-primitives/Cargo.toml
@@ -18,13 +18,13 @@ reth-engine-primitives.workspace = true
 reth-payload-primitives.workspace = true
 reth-payload-validator.workspace = true
 reth-rpc-types-compat.workspace = true
-alloy-rlp.workspace = true
 reth-chain-state.workspace = true
 
 # alloy
 alloy-primitives.workspace = true
 alloy-eips.workspace = true
 alloy-rpc-types-engine.workspace = true
+alloy-rlp.workspace = true
 
 # misc
 serde.workspace = true
@@ -32,3 +32,17 @@ sha2.workspace = true
 
 [dev-dependencies]
 serde_json.workspace = true
+
+[features]
+default = ["std"]
+std = [
+    "reth-chainspec/std",
+    "reth-primitives/std",
+    "alloy-primitives/std",
+    "alloy-eips/std",
+    "alloy-rpc-types-engine/std",
+    "alloy-rlp/std",
+    "serde/std",
+    "sha2/std",
+    "serde_json/std",
+]
diff --git a/crates/ethereum/engine-primitives/src/lib.rs b/crates/ethereum/engine-primitives/src/lib.rs
index f4723bf39..502c80a85 100644
--- a/crates/ethereum/engine-primitives/src/lib.rs
+++ b/crates/ethereum/engine-primitives/src/lib.rs
@@ -7,8 +7,12 @@
 )]
 #![cfg_attr(not(test), warn(unused_crate_dependencies))]
 #![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+extern crate alloc;
 
 mod payload;
+use alloc::sync::Arc;
 use alloy_rpc_types_engine::{ExecutionPayload, ExecutionPayloadSidecar, PayloadError};
 pub use alloy_rpc_types_engine::{
     ExecutionPayloadEnvelopeV2, ExecutionPayloadEnvelopeV3, ExecutionPayloadEnvelopeV4,
@@ -24,13 +28,12 @@ use reth_payload_primitives::{
 use reth_payload_validator::ExecutionPayloadValidator;
 use reth_primitives::{Block, NodePrimitives, SealedBlock};
 use reth_rpc_types_compat::engine::payload::block_to_payload;
-use std::sync::Arc;
 
 /// The types used in the default mainnet ethereum beacon consensus engine.
 #[derive(Debug, Default, Clone, serde::Deserialize, serde::Serialize)]
 #[non_exhaustive]
 pub struct EthEngineTypes<T: PayloadTypes = EthPayloadTypes> {
-    _marker: std::marker::PhantomData<T>,
+    _marker: core::marker::PhantomData<T>,
 }
 
 impl<T: PayloadTypes> PayloadTypes for EthEngineTypes<T> {
diff --git a/crates/ethereum/engine-primitives/src/payload.rs b/crates/ethereum/engine-primitives/src/payload.rs
index 450302598..beb99d027 100644
--- a/crates/ethereum/engine-primitives/src/payload.rs
+++ b/crates/ethereum/engine-primitives/src/payload.rs
@@ -1,5 +1,6 @@
 //! Contains types required for building a payload.
 
+use alloc::{sync::Arc, vec::Vec};
 use alloy_eips::{eip4844::BlobTransactionSidecar, eip4895::Withdrawals, eip7685::Requests};
 use alloy_primitives::{Address, B256, U256};
 use alloy_rlp::Encodable;
@@ -7,13 +8,13 @@ use alloy_rpc_types_engine::{
     ExecutionPayloadEnvelopeV2, ExecutionPayloadEnvelopeV3, ExecutionPayloadEnvelopeV4,
     ExecutionPayloadV1, PayloadAttributes, PayloadId,
 };
+use core::convert::Infallible;
 use reth_chain_state::ExecutedBlock;
 use reth_payload_primitives::{BuiltPayload, PayloadBuilderAttributes};
 use reth_primitives::{EthPrimitives, SealedBlock};
 use reth_rpc_types_compat::engine::payload::{
     block_to_payload_v1, block_to_payload_v3, convert_block_to_payload_field_v2,
 };
-use std::{convert::Infallible, sync::Arc};
 
 /// Contains the built payload.
 ///
@@ -297,7 +298,7 @@ mod tests {
     use super::*;
     use alloy_eips::eip4895::Withdrawal;
     use alloy_primitives::B64;
-    use std::str::FromStr;
+    use core::str::FromStr;
 
     #[test]
     fn attributes_serde() {