From b5f55d9a2b36f6994d9e91b82f22c1980cdf8359 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Tue, 18 Jun 2024 17:33:04 +0200
Subject: [PATCH] chore: make reth-revm compile with no-std (#8931)

---
 crates/revm/Cargo.toml          |  2 ++
 crates/revm/src/batch.rs        |  9 ++++++---
 crates/revm/src/database.rs     |  2 +-
 crates/revm/src/lib.rs          |  4 ++++
 crates/revm/src/state_change.rs | 14 +++++++++++---
 5 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/crates/revm/Cargo.toml b/crates/revm/Cargo.toml
index e8204ee25..5462da738 100644
--- a/crates/revm/Cargo.toml
+++ b/crates/revm/Cargo.toml
@@ -36,4 +36,6 @@ tracing.workspace = true
 reth-trie.workspace = true
 
 [features]
+default = ["std"]
+std = []
 test-utils = ["dep:reth-trie"]
diff --git a/crates/revm/src/batch.rs b/crates/revm/src/batch.rs
index 6f1b55b21..a9a44bff1 100644
--- a/crates/revm/src/batch.rs
+++ b/crates/revm/src/batch.rs
@@ -1,13 +1,16 @@
 //! Helper for handling execution of multiple blocks.
 
 use crate::{precompile::Address, primitives::alloy_primitives::BlockNumber};
+use core::time::Duration;
 use reth_execution_errors::BlockExecutionError;
 use reth_primitives::{Receipt, Receipts, Request, Requests};
 use reth_prune_types::{PruneMode, PruneModes, PruneSegmentError, MINIMUM_PRUNING_DISTANCE};
 use revm::db::states::bundle_state::BundleRetention;
-use std::time::Duration;
 use tracing::debug;
 
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
 /// Takes care of:
 ///  - recording receipts during execution of multiple blocks.
 ///  - pruning receipts according to the pruning configuration.
@@ -78,7 +81,7 @@ impl BlockBatchRecord {
 
     /// Returns all recorded receipts.
     pub fn take_receipts(&mut self) -> Receipts {
-        std::mem::take(&mut self.receipts)
+        core::mem::take(&mut self.receipts)
     }
 
     /// Returns the recorded requests.
@@ -88,7 +91,7 @@ impl BlockBatchRecord {
 
     /// Returns all recorded requests.
     pub fn take_requests(&mut self) -> Vec<Requests> {
-        std::mem::take(&mut self.requests)
+        core::mem::take(&mut self.requests)
     }
 
     /// Returns the [`BundleRetention`] for the given block based on the configured prune modes.
diff --git a/crates/revm/src/database.rs b/crates/revm/src/database.rs
index fc40f474a..3b31788db 100644
--- a/crates/revm/src/database.rs
+++ b/crates/revm/src/database.rs
@@ -1,4 +1,5 @@
 use crate::primitives::alloy_primitives::{BlockNumber, StorageKey, StorageValue};
+use core::ops::{Deref, DerefMut};
 use reth_primitives::{Account, Address, B256, KECCAK_EMPTY, U256};
 use reth_storage_errors::provider::{ProviderError, ProviderResult};
 use revm::{
@@ -6,7 +7,6 @@ use revm::{
     primitives::{AccountInfo, Bytecode},
     Database,
 };
-use std::ops::{Deref, DerefMut};
 
 /// A helper trait responsible for providing that necessary state for the EVM execution.
 ///
diff --git a/crates/revm/src/lib.rs b/crates/revm/src/lib.rs
index 8e5419567..4fb6c30d1 100644
--- a/crates/revm/src/lib.rs
+++ b/crates/revm/src/lib.rs
@@ -7,6 +7,10 @@
 )]
 #![cfg_attr(not(test), warn(unused_crate_dependencies))]
 #![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(not(feature = "std"))]
+extern crate alloc;
 
 /// Contains glue code for integrating reth database into revm's [Database].
 pub mod database;
diff --git a/crates/revm/src/state_change.rs b/crates/revm/src/state_change.rs
index 947c08da7..b9fba6b25 100644
--- a/crates/revm/src/state_change.rs
+++ b/crates/revm/src/state_change.rs
@@ -22,6 +22,14 @@ use revm::{
     },
     Database, DatabaseCommit, Evm,
 };
+
+// reuse revm's hashbrown implementation for no-std
+#[cfg(not(feature = "std"))]
+use crate::precompile::HashMap;
+#[cfg(not(feature = "std"))]
+use alloc::{boxed::Box, format, string::ToString, vec::Vec};
+
+#[cfg(feature = "std")]
 use std::collections::HashMap;
 
 /// Collect all balance changes at the end of the block.
@@ -86,7 +94,7 @@ pub fn apply_blockhashes_update<DB: Database<Error = ProviderError> + DatabaseCo
     parent_block_hash: B256,
 ) -> Result<(), BlockExecutionError>
 where
-    DB::Error: std::fmt::Display,
+    DB::Error: core::fmt::Display,
 {
     // If Prague is not activated or this is the genesis block, no hashes are added.
     if !chain_spec.is_prague_active_at_timestamp(block_timestamp) || block_number == 0 {
@@ -153,7 +161,7 @@ pub fn apply_beacon_root_contract_call<EXT, DB: Database + DatabaseCommit>(
     evm: &mut Evm<'_, EXT, DB>,
 ) -> Result<(), BlockExecutionError>
 where
-    DB::Error: std::fmt::Display,
+    DB::Error: core::fmt::Display,
 {
     if !chain_spec.is_cancun_active_at_timestamp(block_timestamp) {
         return Ok(())
@@ -256,7 +264,7 @@ pub fn apply_withdrawal_requests_contract_call<EXT, DB: Database + DatabaseCommi
     evm: &mut Evm<'_, EXT, DB>,
 ) -> Result<Vec<Request>, BlockExecutionError>
 where
-    DB::Error: std::fmt::Display,
+    DB::Error: core::fmt::Display,
 {
     // get previous env
     let previous_env = Box::new(evm.context.env().clone());