nimbus-eth1/nimbus/transaction/evmc_dynamic_loader.nim
Jordan Hrycaj df1217b7ca
Silence compiler gossip after nim upgrade cont3 (#1466)
* Removed some Windows specific unit test annoyances

details:
+ Short put()/get() cycles on persistent database have a race condition
  with vendor rocksdb. On a specific (and slow) qemu/win7 a 50ms `sleep()`
  in between will mostly do the job (i.e. unless heavy CPU load.) This
  issue was not observed on github/ci.
+ Removed annoyances when qemu/Win7 keeps the rocksdb database files
  locked even after closing the db. The problem is solved by strictly
  using fresh names for each test. No assumption made to be able to
  properly clean up. This issue was not observed on github/ci.

* Silence some compiler gossip -- part 7, misc/non(sync or graphql)

details:
  Adding some missing exception annotation
2023-02-14 20:27:17 +00:00

128 lines
4.6 KiB
Nim

# Nimbus - Dynamic loader for EVM modules as shared libraries / DLLs
#
# Copyright (c) 2019-2021 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
std/[dynlib, strformat, strutils, os],
chronicles,
evmc/evmc, ../config
# The built-in Nimbus EVM, via imported C function.
proc evmc_create_nimbus_evm(): ptr evmc_vm {.cdecl, importc.}
# Import this module to link in the definition of `evmc_create_nimbus_evm`.
# Nim thinks the module is unused because the function is only called via
# `.exportc` -> `.importc`.
{.warning[UnusedImport]: off.}:
import ./evmc_vm_glue
var evmcLibraryPath {.threadvar.}: string
## Library path set by `--evm` command line option.
## Like the loaded EVMs themselves, this is thread-local for Nim simplicity.
proc evmcSetLibraryPath*(path: string) =
evmcLibraryPath = path
proc evmcLoadVMGetCreateFn(): (evmc_create_vm_name_fn, string) =
var path = evmcLibraryPath
if path.len == 0:
path = getEnv("NIMBUS_EVM")
# Use built-in EVM if no other is specified.
if path.len == 0:
return (evmc_create_nimbus_evm, "built-in")
# The steps below match the EVMC Loader documentation, copied here:
#
# - The filename is used to guess the EVM name and the name of the create
# function. The create function name is constructed by the following
# rules. Consider example path: "/ethereum/libexample-interpreter.so.1.0".
# - The filename is taken from the path: "libexample-interpreter.so.1.0".
# - The "lib" prefix and all file extensions are stripped from the name:
# "example-interpreter".
# - All "-" are replaced with "_" to construct base name:
# "example_interpreter"
# - The function name "evmc_create_" + base name is searched in the library:
# "evmc_create_example_interpreter",
# - If the function is not found, the function name "evmc_create" is searched
# in the library.
# Load the library.
let lib = loadLib(path, false)
if lib.isNil:
warn "Error loading EVM library", path
return (nil, "")
# Find filename in the path.
var symbolName = os.extractFilename(path)
# Skip "lib" prefix if present. Note, `removePrefix` only removes at the
# start despite its documentation.
symbolName.removePrefix("lib")
# Trim all file extesnsions. (`os.splitFile` only removes the last.)
symbolName = symbolName.split('.', 1)[0]
# Replace all "-" with "_".
symbolName = symbolName.replace('-', '_')
# Search for the built function name.
symbolName = "evmc_create_" & symbolName
var sym = symAddr(lib, symbolName)
if sym.isNil:
const fallback = "evmc_create"
sym = symAddr(lib, fallback)
if sym.isNil:
warn "EVMC create function not found in library", path
warn "Tried this library symbol", symbol=symbolName
warn "Tried this library symbol", symbol=fallback
return (nil, "")
return (cast[evmc_create_vm_name_fn](sym), path)
proc evmcLoadVMShowDetail(): ptr evmc_vm {.raises: [CatchableError].} =
let (vmCreate, vmDescription) = evmcLoadVMGetCreateFn()
if vmCreate.isNil:
return nil
var vm: ptr evmc_vm
try:
{.gcsafe.}:
vm = vmCreate()
except CatchableError as e:
raise e
except Exception as e:
{.warning: "Kludge(BareExcept): `evmc_create_nimbus_evm()` in vendor package needs to be double checked and updated".}
raiseAssert "Ooops evmcLoadVMShowDetail(): name=" &
$e.name & " msg=" & e.msg
if vm.isNil:
warn "The loaded EVM did not create a VM when requested",
`from`=vmDescription
return nil
if vm.abi_version != EVMC_ABI_VERSION:
warn "The loaded EVM is for an incompatible EVMC ABI",
requireABI=EVMC_ABI_VERSION, loadedABI=vm.abi_version,
`from`=vmDescription
warn "The loaded EVM will not be used", `from`=vmDescription
return nil
let name = if vm.name.isNil: "<nil>" else: $vm.name
let version = if vm.version.isNil: "<nil>" else: $vm.version
info "Using EVM", name=name, version=version, `from`=vmDescription
return vm
proc evmcLoadVMCached*(): ptr evmc_vm {.raises: [CatchableError].} =
# TODO: Make this open the VM library once per process. Currently it does
# so once per thread, but at least this is thread-safe.
var vm {.threadvar.}: ptr evmc_vm
var triedLoading {.threadvar.}: bool
if not triedLoading:
triedLoading = true
vm = evmcLoadVMShowDetail()
return vm