chore: Make reth-ethereum-consensus no_std compatible (#15821)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

.github/assets/check_rv32imac.sh

@@ -25,6 +25,7 @@ crates_to_check=(
     reth-evm-ethereum
     reth-ethereum-forks
     reth-ethereum-primitives
+    reth-ethereum-consensus
 
     ## optimism
     reth-optimism-chainspec

Cargo.toml

@@ -349,7 +349,7 @@ reth-era-downloader = { path = "crates/era-downloader" }
 reth-eth-wire = { path = "crates/net/eth-wire" }
 reth-eth-wire-types = { path = "crates/net/eth-wire-types" }
 reth-ethereum-cli = { path = "crates/ethereum/cli" }
-reth-ethereum-consensus = { path = "crates/ethereum/consensus" }
+reth-ethereum-consensus = { path = "crates/ethereum/consensus", default-features = false }
 reth-ethereum-engine-primitives = { path = "crates/ethereum/engine-primitives", default-features = false }
 reth-ethereum-forks = { path = "crates/ethereum-forks", default-features = false }
 reth-ethereum-payload-builder = { path = "crates/ethereum/payload" }

crates/ethereum/consensus/Cargo.toml

@@ -25,6 +25,21 @@ alloy-consensus.workspace = true
 
 tracing.workspace = true
 
+[features]
+default = ["std"]
+std = [
+    "alloy-consensus/std",
+    "alloy-eips/std",
+    "alloy-primitives/std",
+    "reth-chainspec/std",
+    "reth-consensus/std",
+    "reth-consensus-common/std",
+    "reth-ethereum-primitives/std",
+    "reth-execution-types/std",
+    "reth-primitives-traits/std",
+    "tracing/std",
+]
+
 [dev-dependencies]
 reth-ethereum-primitives.workspace = true
 alloy-primitives = { workspace = true, features = ["getrandom"] }

crates/ethereum/consensus/src/lib.rs

@@ -7,9 +7,13 @@
 )]
 #![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;
+
+use alloc::{fmt::Debug, sync::Arc};
 use alloy_consensus::EMPTY_OMMER_ROOT_HASH;
-use alloy_eips::{eip7840::BlobParams, merge::ALLOWED_FUTURE_BLOCK_TIME_SECONDS};
+use alloy_eips::eip7840::BlobParams;
 use alloy_primitives::U256;
 use reth_chainspec::{EthChainSpec, EthereumHardforks};
 use reth_consensus::{Consensus, ConsensusError, FullConsensus, HeaderValidator};
@@ -24,7 +28,6 @@ use reth_primitives_traits::{
     constants::{GAS_LIMIT_BOUND_DIVISOR, MINIMUM_GAS_LIMIT},
     Block, BlockHeader, NodePrimitives, RecoveredBlock, SealedBlock, SealedHeader,
 };
-use std::{fmt::Debug, sync::Arc, time::SystemTime};
 
 mod validation;
 pub use validation::validate_block_post_execution;
@@ -241,14 +244,20 @@ where
             // order, making those checks obsolete.
 
             // Check if timestamp is in the future. Clock can drift but this can be consensus issue.
-            let present_timestamp =
-                SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap().as_secs();
-
-            if header.timestamp() > present_timestamp + ALLOWED_FUTURE_BLOCK_TIME_SECONDS {
-                return Err(ConsensusError::TimestampIsInFuture {
-                    timestamp: header.timestamp(),
-                    present_timestamp,
-                })
+            #[cfg(feature = "std")]
+            {
+                let present_timestamp = std::time::SystemTime::now()
+                    .duration_since(std::time::SystemTime::UNIX_EPOCH)
+                    .unwrap()
+                    .as_secs();
+                if header.timestamp() >
+                    present_timestamp + alloy_eips::merge::ALLOWED_FUTURE_BLOCK_TIME_SECONDS
+                {
+                    return Err(ConsensusError::TimestampIsInFuture {
+                        timestamp: header.timestamp(),
+                        present_timestamp,
+                    })
+                }
             }
 
             validate_header_extra_data(header)?;

crates/ethereum/consensus/src/validation.rs

@@ -1,3 +1,4 @@
+use alloc::vec::Vec;
 use alloy_consensus::{proofs::calculate_receipt_root, BlockHeader, TxReceipt};
 use alloy_eips::eip7685::Requests;
 use alloy_primitives::{Bloom, B256};

crates/ethereum/reth/Cargo.toml

@@ -49,6 +49,7 @@ default = ["std"]
 std = [
     "reth-chainspec/std",
     "reth-ethereum-primitives/std",
+    "reth-ethereum-consensus/std",
     "reth-primitives-traits/std",
     "reth-consensus?/std",
     "reth-consensus-common?/std",
@@ -84,7 +85,17 @@ test-utils = [
     "reth-transaction-pool?/test-utils",
 ]
 
-full = ["consensus", "evm", "node", "provider", "rpc", "exex", "trie", "pool", "network"]
+full = [
+    "consensus",
+    "evm",
+    "node",
+    "provider",
+    "rpc",
+    "exex",
+    "trie",
+    "pool",
+    "network",
+]
 
 alloy-compat = ["reth-ethereum-primitives/alloy-compat"]
 cli = ["dep:reth-ethereum-cli"]