integrate evmc 'getStorage'

nimbus/vm/computation.nim

@@ -80,6 +80,12 @@ template accountExists*(c: Computation, address: EthAddress): bool =
   else:
     c.vmState.readOnlyStateDB.accountExists(address)
 
+template getStorage*(c: Computation, slot: Uint256): Uint256 =
+  when evmc_enabled:
+    c.host.getStorage(c.msg.contractAddress, slot)
+  else:
+    c.vmState.readOnlyStateDB.getStorage(c.msg.contractAddress, slot)[0]
+
 proc newComputation*(vmState: BaseVMState, message: Message): Computation =
   new result
   result.vmState = vmState

nimbus/vm/evmc_api.nim

@@ -48,7 +48,8 @@ proc getStorage*(ctx: HostContext, address: EthAddress, key: Uint256): Uint256 =
   var
     address = toEvmc(address)
     key = toEvmc(key)
-  Uint256.fromEvmc ctx.host.get_storage(ctx.context, address.addr, key.addr)
+  {.gcsafe.}:
+    Uint256.fromEvmc ctx.host.get_storage(ctx.context, address.addr, key.addr)
 
 proc setStorage*(ctx: HostContext, address: EthAddress,
                  key, value: Uint256): evmc_storage_status =

nimbus/vm/interpreter/opcodes_impl.nim

@@ -426,15 +426,13 @@ op mstore8, inline = true, memStartPos, value:
 
 op sload, inline = true, slot:
   ## 0x54, Load word from storage.
-
-  let (value, _) = c.vmState.readOnlyStateDB.getStorage(c.msg.contractAddress, slot)
-  push(value)
+  push: c.getStorage(slot)
 
 op sstore, inline = false, slot, value:
   ## 0x55, Save word to storage.
   checkInStaticContext(c)
 
-  let (currentValue, existing) = c.vmState.readOnlyStateDB.getStorage(c.msg.contractAddress, slot)
+  let currentValue = c.getStorage(slot)
 
   let
     gasParam = GasParams(kind: Op.Sstore, s_isStorageEmpty: currentValue.isZero)
@@ -930,7 +928,7 @@ op sstoreEIP2200, inline = false, slot, value:
     raise newException(OutOfGas, "Gas not enough to perform EIP2200 SSTORE")
 
   let stateDB = c.vmState.readOnlyStateDB
-  let (currentValue, existing) = stateDB.getStorage(c.msg.contractAddress, slot)
+  let currentValue = c.getStorage(slot)
 
   let
     gasParam = GasParams(kind: Op.Sstore,