nimbus-eth1/nimbus/evm/interpreter/op_handlers/oph_create.nim

# Nimbus
# Copyright (c) 2021-2024 Status Research & Development GmbH
# Licensed under either of
#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
#    http://www.apache.org/licenses/LICENSE-2.0)
#  * MIT license ([LICENSE-MIT](LICENSE-MIT) or
#    http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed except
# according to those terms.

## EVM Opcode Handlers: Create Operations
## ======================================
##

{.push raises: [].} # basically the annotation type of a `VmOpFn`

import
  ../../../constants,
  ../../evm_errors,
  ../../../common/evmforks,
  ../../../utils/utils,
  ../../computation,
  ../../memory,
  ../../stack,
  ../../types,
  ../gas_costs,
  ../gas_meter,
  ../op_codes,
  ./oph_defs,
  ./oph_helpers,
  chronicles,
  eth/common,
  eth/common/eth_types,
  stint

when not defined(evmc_enabled):
  import
    ../../state,
    ../../../db/ledger

# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------

when evmc_enabled:
  template execSubCreate(c: Computation; msg: ref nimbus_message) =
    c.chainTo(msg):
      c.gasMeter.returnGas(GasInt c.res.gas_left)
      if c.res.status_code == EVMC_SUCCESS:
        ? c.stack.top(c.res.create_address)
      elif c.res.status_code == EVMC_REVERT:
        # From create, only use `outputData` if child returned with `REVERT`.
        c.returnData = @(makeOpenArray(c.res.output_data, c.res.output_size.int))
      if not c.res.release.isNil:
        c.res.release(c.res)
      ok()

else:
  proc execSubCreate(c: Computation; childMsg: Message;
                    salt: ContractSalt = ZERO_CONTRACTSALT) {.raises: [].} =
    ## Create new VM -- helper for `Create`-like operations

    # need to provide explicit <c> and <child> for capturing in chainTo proc()
    var
      child = newComputation(c.vmState, false, childMsg, salt)

    c.chainTo(child):
      if not child.shouldBurnGas:
        c.gasMeter.returnGas(child.gasMeter.gasRemaining)

      if child.isSuccess:
        c.merge(child)
        ? c.stack.top child.msg.contractAddress
      elif not child.error.burnsGas: # Means return was `REVERT`.
        # From create, only use `outputData` if child returned with `REVERT`.
        c.returnData = child.output
      ok()


# ------------------------------------------------------------------------------
# Private, op handlers implementation
# ------------------------------------------------------------------------------


proc createOp(k: var VmCtx): EvmResultVoid =
  ## 0xf0, Create a new account with associated code
  ? checkInStaticContext(k.cpt)

  let
    cpt       = k.cpt
    endowment = ? cpt.stack.popInt()
    memPos    = ? cpt.stack.popSafeInt()
    memLen    = ? cpt.stack.peekSafeInt()

  ? cpt.stack.top(0)

  # EIP-3860
  if cpt.fork >= FkShanghai and memLen > EIP3860_MAX_INITCODE_SIZE:
    trace "Initcode size exceeds maximum", initcodeSize = memLen
    return err(opErr(InvalidInitCode))

  let
    gasParams = GasParams(
      kind:              Create,
      cr_currentMemSize: cpt.memory.len,
      cr_memOffset:      memPos,
      cr_memLength:      memLen)
    res = cpt.gasCosts[Create].cr_handler(1.u256, gasParams)

  ? cpt.opcodeGastCost(Create,
    res.gasCost, reason = "CREATE: GasCreate + memLen * memory expansion")
  cpt.memory.extend(memPos, memLen)
  cpt.returnData.setLen(0)

  if cpt.msg.depth >= MaxCallDepth:
    debug "Computation Failure",
      reason = "Stack too deep",
      maxDepth = MaxCallDepth,
      depth = cpt.msg.depth
    return ok()

  if endowment != 0:
    let senderBalance = cpt.getBalance(cpt.msg.contractAddress)
    if senderBalance < endowment:
      debug "Computation Failure",
        reason = "Insufficient funds available to transfer",
        required = endowment,
        balance = senderBalance
      return ok()

  var createMsgGas = cpt.gasMeter.gasRemaining
  if cpt.fork >= FkTangerine:
    createMsgGas -= createMsgGas div 64
  ? cpt.gasMeter.consumeGas(createMsgGas, reason = "CREATE msg gas")

  when evmc_enabled:
    let
      msg = new(nimbus_message)
      c   = cpt
    msg[] = nimbus_message(
      kind: EVMC_CREATE,
      depth: (cpt.msg.depth + 1).int32,
      gas: createMsgGas,
      sender: cpt.msg.contractAddress,
      input_data: cpt.memory.readPtr(memPos),
      input_size: memLen.uint,
      value: toEvmc(endowment),
      create2_salt: toEvmc(ZERO_CONTRACTSALT),
    )
    c.execSubCreate(msg)
  else:
    cpt.execSubCreate(
      childMsg = Message(
        kind:   EVMC_CREATE,
        depth:  cpt.msg.depth + 1,
        gas:    createMsgGas,
        sender: cpt.msg.contractAddress,
        value:  endowment,
        data:   @(cpt.memory.read(memPos, memLen))))
  ok()

# ---------------------

proc create2Op(k: var VmCtx): EvmResultVoid =
  ## 0xf5, Behaves identically to CREATE, except using keccak256
  ? checkInStaticContext(k.cpt)

  let
    cpt       = k.cpt
    endowment = ? cpt.stack.popInt()
    memPos    = ? cpt.stack.popSafeInt()
    memLen    = ? cpt.stack.popSafeInt()
    salt256   = ? cpt.stack.peekInt()
    salt      = ContractSalt(bytes: salt256.toBytesBE)

  ? cpt.stack.top(0)

  # EIP-3860
  if cpt.fork >= FkShanghai and memLen > EIP3860_MAX_INITCODE_SIZE:
    trace "Initcode size exceeds maximum", initcodeSize = memLen
    return err(opErr(InvalidInitCode))

  let
    gasParams = GasParams(
      kind:              Create,
      cr_currentMemSize: cpt.memory.len,
      cr_memOffset:      memPos,
      cr_memLength:      memLen)
    res = cpt.gasCosts[Create].cr_handler(1.u256, gasParams)

  let gasCost = res.gasCost + cpt.gasCosts[Create2].m_handler(0, 0, memLen)

  ? cpt.opcodeGastCost(Create2,
    gasCost, reason = "CREATE2: GasCreate + memLen * memory expansion")
  cpt.memory.extend(memPos, memLen)
  cpt.returnData.setLen(0)

  if cpt.msg.depth >= MaxCallDepth:
    debug "Computation Failure",
      reason = "Stack too deep",
      maxDepth = MaxCallDepth,
      depth = cpt.msg.depth
    return ok()

  if endowment != 0:
    let senderBalance = cpt.getBalance(cpt.msg.contractAddress)
    if senderBalance < endowment:
      debug "Computation Failure",
        reason = "Insufficient funds available to transfer",
        required = endowment,
        balance = senderBalance
      return ok()

  var createMsgGas = cpt.gasMeter.gasRemaining
  if cpt.fork >= FkTangerine:
    createMsgGas -= createMsgGas div 64
  ? cpt.gasMeter.consumeGas(createMsgGas, reason = "CREATE2 msg gas")

  when evmc_enabled:
    let
      msg = new(nimbus_message)
      c   = cpt
    msg[] = nimbus_message(
      kind: EVMC_CREATE2,
      depth: (cpt.msg.depth + 1).int32,
      gas: createMsgGas,
      sender: cpt.msg.contractAddress,
      input_data: cpt.memory.readPtr(memPos),
      input_size: memLen.uint,
      value: toEvmc(endowment),
      create2_salt: toEvmc(salt),
    )
    c.execSubCreate(msg)
  else:
    cpt.execSubCreate(
      salt = salt,
      childMsg = Message(
        kind:   EVMC_CREATE2,
        depth:  cpt.msg.depth + 1,
        gas:    createMsgGas,
        sender: cpt.msg.contractAddress,
        value:  endowment,
        data:   @(cpt.memory.read(memPos, memLen))))
  ok()

# ------------------------------------------------------------------------------
# Public, op exec table entries
# ------------------------------------------------------------------------------

const
  VmOpExecCreate*: seq[VmOpExec] = @[

    (opCode: Create,    ## 0xf0, Create a new account with associated code
     forks: VmOpAllForks,
     name: "create",
     info: "Create a new account with associated code",
     exec: (prep: VmOpIgnore,
            run: createOp,
            post: VmOpIgnore)),

    (opCode: Create2,   ## 0xf5, Create using keccak256
     forks: VmOpConstantinopleAndLater,
     name: "create2",
     info: "Behaves identically to CREATE, except using keccak256",
     exec: (prep: VmOpIgnore,
            run: create2Op,
            post: VmOpIgnore))]

# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------