From 76031ccbe4d50ea57f13cb2478b94c53db6fb6c4 Mon Sep 17 00:00:00 2001
From: Jamie Lokier <jamie@shareable.org>
Date: Thu, 27 May 2021 08:45:55 +0100
Subject: [PATCH] Transaction: EIP-2929 (Berlin): Initial access list

Signed-off-by: Jamie Lokier <jamie@shareable.org>
---
 nimbus/transaction/call_common.nim | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/nimbus/transaction/call_common.nim b/nimbus/transaction/call_common.nim
index 333cfaeca..0f0ad53e7 100644
--- a/nimbus/transaction/call_common.nim
+++ b/nimbus/transaction/call_common.nim
@@ -54,6 +54,22 @@ proc hostToComputationMessage(msg: EvmcMessage): Message =
     flags:           if msg.isStatic: emvcStatic else: emvcNoFlags
   )
 
+proc initialAccessListEIP2929(call: CallParams) =
+  # EIP2929 initial access list.
+  let vmState = call.vmState
+  if vmState.fork < FkBerlin:
+    return
+
+  vmState.mutateStateDB:
+    db.accessList(call.sender)
+    # For contract creations the EVM will add the contract address to the
+    # access list itself, after calculating the new contract address.
+    if not call.isCreate:
+      db.accessList(call.to)
+    # TODO: Check this only adds the correct subset of precompiles.
+    for c in activePrecompiles():
+      db.accessList(c)
+
 proc setupCall(call: CallParams, useIntrinsic: bool): TransactionHost =
   let vmState = call.vmState
   vmState.setupTxContext(
@@ -100,6 +116,9 @@ proc runComputation*(call: CallParams): CallResult =
   let host = setupCall(call, true)
   let c = host.computation
 
+  # Must come after `setupCall` for correct fork.
+  initialAccessListEIP2929(call)
+
   # Charge for gas.
   host.vmState.mutateStateDB:
     db.subBalance(call.sender, call.gasLimit.u256 * call.gasPrice.u256)