integrate evmc 'accountExists'

nimbus/vm/computation.nim

@@ -74,6 +74,12 @@ template getBlockHash*(c: Computation, blockNumber: Uint256): Hash256 =
   else:
     c.vmState.getAncestorHash(blockNumber.vmWordToBlockNumber)
 
+template accountExists*(c: Computation, address: EthAddress): bool =
+  when evmc_enabled:
+    c.host.accountExists(address)
+  else:
+    c.vmState.readOnlyStateDB.accountExists(address)
+
 proc newComputation*(vmState: BaseVMState, message: Message): Computation =
   new result
   result.vmState = vmState

nimbus/vm/evmc_api.nim

@@ -29,19 +29,20 @@ proc getTxContext*(ctx: HostContext): evmc_tx_context =
     ctx.host.get_tx_context(ctx.context)
 
 proc getBlockHash*(ctx: HostContext, number: Uint256): Hash256 =
+  let
+    blockNumber = ctx.getTxContext().block_number.u256
+    ancestorDepth  = blockNumber - number - 1
+  if ancestorDepth >= constants.MAX_PREV_HEADER_DEPTH:
+    return
+  if number >= blockNumber:
+    return
   {.gcsafe.}:
-    let
-      blockNumber = ctx.getTxContext().block_number.u256
-      ancestorDepth  = blockNumber - number - 1
-    if ancestorDepth >= constants.MAX_PREV_HEADER_DEPTH:
-      return
-    if number >= blockNumber:
-      return
     Hash256.fromEvmc ctx.host.get_block_hash(ctx.context, number.truncate(int64))
 
 proc accountExists*(ctx: HostContext, address: EthAddress): bool =
   var address = toEvmc(address)
-  ctx.host.account_exists(ctx.context, address.addr).bool
+  {.gcsafe.}:
+    ctx.host.account_exists(ctx.context, address.addr).bool
 
 proc getStorage*(ctx: HostContext, address: EthAddress, key: Uint256): Uint256 =
   var

nimbus/vm/interpreter/opcodes_impl.nim

@@ -695,7 +695,7 @@ template genCall(callName: untyped, opCode: Op): untyped =
     let isNewAccount = if c.fork >= FkSpurious:
                          c.vmState.readOnlyStateDb.isDeadAccount(contractAddress)
                        else:
-                         not c.vmState.readOnlyStateDb.accountExists(contractAddress)
+                         not c.accountExists(contractAddress)
 
     let (memOffset, memLength) = if calcMemSize(memInPos, memInLen) > calcMemSize(memOutPos, memOutLen):
                                     (memInPos, memInLen)
@@ -855,7 +855,7 @@ op selfDestructEip150, inline = false:
   let beneficiary = c.stack.popAddress()
 
   let gasParams = GasParams(kind: SelfDestruct,
-    sd_condition: not c.vmState.readOnlyStateDb.accountExists(beneficiary)
+    sd_condition: not c.accountExists(beneficiary)
     )
 
   let gasCost = c.gasCosts[SelfDestruct].c_handler(0.u256, gasParams).gasCost
@@ -913,7 +913,7 @@ op extCodeHash, inline = true:
   # this is very inefficient, it calls underlying
   # database too much, we can reduce it by implementing accounts
   # cache
-  if not c.vmState.readOnlyStateDB.accountExists(address):
+  if not c.accountExists(address):
     push: 0
     return