159 lines
6.7 KiB
Nim
159 lines
6.7 KiB
Nim
# Nimbus - Services available to EVM code that is run for a transaction
|
|
#
|
|
# Copyright (c) 2019-2024 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.
|
|
|
|
{.push raises: [].}
|
|
|
|
import
|
|
eth/common/eth_types,
|
|
stew/ptrops,
|
|
stint,
|
|
".."/[vm_types, vm_computation],
|
|
../utils/utils,
|
|
"."/[host_types, host_trace]
|
|
|
|
proc evmcResultRelease(res: var EvmcResult) {.cdecl, gcsafe.} =
|
|
dealloc(res.output_data)
|
|
|
|
proc beforeExecCreateEvmcNested(host: TransactionHost,
|
|
m: EvmcMessage): Computation =
|
|
# TODO: use evmc_message to avoid copy
|
|
let childMsg = Message(
|
|
kind: CallKind(m.kind.ord),
|
|
depth: m.depth,
|
|
gas: m.gas,
|
|
sender: m.sender.fromEvmc,
|
|
value: m.value.fromEvmc,
|
|
data: @(makeOpenArray(m.inputData, m.inputSize.int))
|
|
)
|
|
return newComputation(host.vmState, false, childMsg,
|
|
cast[ContractSalt](m.create2_salt))
|
|
|
|
proc afterExecCreateEvmcNested(host: TransactionHost, child: Computation,
|
|
res: var EvmcResult) {.inline.} =
|
|
if not child.shouldBurnGas:
|
|
res.gas_left = child.gasMeter.gasRemaining
|
|
|
|
if child.isSuccess:
|
|
host.computation.merge(child)
|
|
res.status_code = EVMC_SUCCESS
|
|
res.create_address = child.msg.contractAddress.toEvmc
|
|
else:
|
|
res.status_code = child.evmcStatus
|
|
if child.output.len > 0:
|
|
# TODO: can we move the ownership of seq to raw pointer?
|
|
res.output_size = child.output.len.uint
|
|
res.output_data = cast[ptr byte](alloc(child.output.len))
|
|
copyMem(res.output_data, child.output[0].addr, child.output.len)
|
|
res.release = evmcResultRelease
|
|
|
|
proc beforeExecCallEvmcNested(host: TransactionHost,
|
|
m: EvmcMessage): Computation {.inline.} =
|
|
let childMsg = Message(
|
|
kind: CallKind(m.kind.ord),
|
|
depth: m.depth,
|
|
gas: m.gas,
|
|
sender: m.sender.fromEvmc,
|
|
codeAddress: m.code_address.fromEvmc,
|
|
contractAddress: if m.kind == EVMC_CALL:
|
|
m.recipient.fromEvmc
|
|
else:
|
|
host.computation.msg.contractAddress,
|
|
value: m.value.fromEvmc,
|
|
data: @(makeOpenArray(m.inputData, m.inputSize.int)),
|
|
flags: m.flags,
|
|
)
|
|
return newComputation(host.vmState, false, childMsg)
|
|
|
|
proc afterExecCallEvmcNested(host: TransactionHost, child: Computation,
|
|
res: var EvmcResult) {.inline.} =
|
|
if not child.shouldBurnGas:
|
|
res.gas_left = child.gasMeter.gasRemaining
|
|
|
|
if child.isSuccess:
|
|
host.computation.merge(child)
|
|
res.status_code = EVMC_SUCCESS
|
|
else:
|
|
res.status_code = child.evmcStatus
|
|
|
|
if child.output.len > 0:
|
|
# TODO: can we move the ownership of seq to raw pointer?
|
|
res.output_size = child.output.len.uint
|
|
res.output_data = cast[ptr byte](alloc(child.output.len))
|
|
copyMem(res.output_data, child.output[0].addr, child.output.len)
|
|
res.release = evmcResultRelease
|
|
|
|
# The next three functions are designed so `callEvmcNested` uses very small C
|
|
# stack usage for each level of nested EVM calls.
|
|
#
|
|
# To keep the C stack usage small when there are deeply nested EVM calls,
|
|
# `callEvmcNested` must use as little stack as possible, going from the EVM
|
|
# which calls it to the nested EVM which it calls.
|
|
#
|
|
# First, `callEvmcNested` itself is `template` so it is inlined to the caller
|
|
# at Nim level, not C level. Only at Nim level is inlining guaranteed across
|
|
# `import`. This saves a C stack frame, which matters because some C compilers
|
|
# reserve space for 1-3 copies of the large `EvmcResult` return value.
|
|
#
|
|
# Second, the complicated parts of preparation and return are done in
|
|
# out-of-line functions `beforeExecEvmcNested` and `afterExecEvmcNested`. They
|
|
# are annotated with `{.noinline.}` to make sure they are out-of-line. The
|
|
# annotation ensures they don't contribute to the stack frame of
|
|
# `callEvmcNested`, because otherwise the compiler can optimistically inline.
|
|
# (Even across modules when using `-flto`).
|
|
#
|
|
# The functions `beforeExecEvmcNested` and `afterExecEvmcNested` can use as
|
|
# much stack as they like.
|
|
|
|
proc beforeExecEvmcNested(host: TransactionHost, msg: EvmcMessage): Computation
|
|
# This function must be declared with `{.noinline.}` to make sure it doesn't
|
|
# contribute to the stack frame of `callEvmcNested` below.
|
|
{.noinline, gcsafe, raises: [ValueError].} =
|
|
# `call` is special. Most host functions do `flip256` in `evmc_host_glue`
|
|
# and `show` in `host_services`, but `call` needs to minimise C stack used
|
|
# by nested EVM calls. Just `flip256` in glue's `call` adds a lot of
|
|
# stack: +65% in tests, enough to blow our 750kiB test stack target and
|
|
# crash. Easily avoided by doing `flip256` and `show` out-of-line here.
|
|
var msg = msg # Make a local copy that's ok to modify.
|
|
msg.value = flip256(msg.value)
|
|
host.showCallEntry(msg)
|
|
let c = if msg.kind == EVMC_CREATE or msg.kind == EVMC_CREATE2:
|
|
beforeExecCreateEvmcNested(host, msg)
|
|
else:
|
|
beforeExecCallEvmcNested(host, msg)
|
|
when defined(evmc_enabled):
|
|
c.host.init(cast[ptr nimbus_host_interface](host.hostInterface),
|
|
cast[typeof(c.host.context)](host))
|
|
host.saveComputation.add(host.computation)
|
|
host.computation = c
|
|
return c
|
|
|
|
proc afterExecEvmcNested(host: TransactionHost, child: Computation,
|
|
kind: EvmcCallKind): EvmcResult
|
|
# This function must be declared with `{.noinline.}` to make sure it doesn't
|
|
# contribute to the stack frame of `callEvmcNested` below.
|
|
{.noinline, gcsafe, raises: [ValueError].} =
|
|
host.computation = host.saveComputation[^1]
|
|
host.saveComputation[^1] = nil
|
|
host.saveComputation.setLen(host.saveComputation.len - 1)
|
|
if kind == EVMC_CREATE or kind == EVMC_CREATE2:
|
|
afterExecCreateEvmcNested(host, child, result)
|
|
else:
|
|
afterExecCallEvmcNested(host, child, result)
|
|
host.showCallReturn(result, kind.isCreate)
|
|
|
|
template callEvmcNested*(host: TransactionHost, msg: EvmcMessage): EvmcResult =
|
|
# `call` is special. The C stack usage must be kept small for deeply nested
|
|
# EVM calls. To ensure small stack, this function must use `template` to
|
|
# inline at Nim level (same for `host.call(msg)`). `{.inline.}` is not good
|
|
# enough. Due to object return it ends up using a lot more stack. (Note
|
|
# that template parameters `host` and `msg` are multiple-evaluated here;
|
|
# simple expressions must be used when calling.)
|
|
let child = beforeExecEvmcNested(host, msg)
|
|
child.execCallOrCreate()
|
|
afterExecEvmcNested(host, child, msg.kind)
|