unifying contract collision detection

nimbus/p2p/executor.nim

@@ -29,7 +29,6 @@ proc processTransaction*(tx: Transaction, sender: EthAddress, vmState: BaseVMSta
     if balance < upfrontGasCost: break
 
     let recipient = tx.getRecipient()
-    let isCollision = vmState.readOnlyStateDb().hasCodeOrNonce(recipient)
 
     var c = setupComputation(vmState, tx, sender, recipient, fork)
     if c.isNil: # OOG in setupComputation
@@ -40,7 +39,6 @@ proc processTransaction*(tx: Transaction, sender: EthAddress, vmState: BaseVMSta
       db.incNonce(sender)
       db.subBalance(sender, upfrontGasCost)
 
-    if tx.isContractCreation and isCollision: break
     execComputation(c)
     if not c.shouldBurnGas:
       gasUsed = c.refundGas(tx, sender)

nimbus/vm/computation.nim

@@ -144,7 +144,13 @@ proc applyMessage*(c: Computation, opCode: static[Op]) =
   defer:
     c.dispose()
 
-  when opCode in {Create, Create2}:
+  when opCode == Create:
+    if c.vmState.readOnlyStateDb().hasCodeOrNonce(c.msg.contractAddress):
+      c.setError("Address collision when creating contract address={c.msg.contractAddress.toHex}", true)
+      c.rollback()
+      c.nextProc()
+      return
+
     c.vmState.mutateStateDb:
       db.clearStorage(c.msg.contractAddress)
       if c.fork >= FkSpurious:

nimbus/vm/interpreter/opcodes_impl.nim

@@ -539,8 +539,7 @@ proc setupCreate(c: Computation, memPos, len: int, value: Uint256, opCode: stati
     callData = c.memory.read(memPos, len)
 
   var
-    createMsgGas = c.getGasRemaining()
-
+    createMsgGas = c.gasMeter.gasRemaining
   if c.fork >= FkTangerine:
     createMsgGas -= createMsgGas div 64
 
@@ -555,25 +554,16 @@ proc setupCreate(c: Computation, memPos, len: int, value: Uint256, opCode: stati
   when opCode == Create:
     const callKind = evmcCreate
     c.vmState.mutateStateDB:
-      # Regarding collisions, see: https://github.com/status-im/nimbus/issues/133
-      # See: https://github.com/ethereum/EIPs/issues/684
       let creationNonce = db.getNonce(c.msg.contractAddress)
       db.setNonce(c.msg.contractAddress, creationNonce + 1)
 
       contractAddress = generateAddress(c.msg.contractAddress, creationNonce)
-      isCollision = db.hasCodeOrNonce(contractAddress)
   else:
     const callKind = evmcCreate2
     c.vmState.mutateStateDB:
       db.incNonce(c.msg.contractAddress)
       let salt = c.stack.popInt()
       contractAddress = generateSafeAddress(c.msg.contractAddress, salt, callData)
-      isCollision = db.hasCodeOrNonce(contractAddress)
-
-  if isCollision:
-    debug "Address collision while creating contract", address = contractAddress.toHex
-    push: 0
-    return
 
   let childMsg = Message(
     kind: callKind,

nimbus/vm_state_transactions.nim

@@ -70,7 +70,8 @@ proc execComputation*(c: Computation) =
   if c.fork >= FkSpurious:
     c.collectTouchedAccounts()
 
-  c.refundSelfDestruct()
+  if c.isSuccess:
+    c.refundSelfDestruct()
   c.vmState.suicides = c.getSuicides()
 
   c.vmstate.status = c.isSuccess