## Why this should be merged
Aligns precompiled contracts with the pattern used in
`vm.EVMInterpreter` for regular contracts and simplifies gas accounting
by using existing mechanisms. The most notable simplification occurs
when there are multiple error paths that return early and have to
account for consumed gas (any local solution would likely just mirror
this one).
This forms part of a broader, long-term direction of feature parity
between precompiled and bytecode contracts, exposed via
`vm.PrecompileEnvironment`.
The `vm.Contract.Value()` method is also exposed as a natural
accompaniment to this change.
## How this works
The original signature for `vm.PrecompiledStatefulContract` received the
amount of gas available and then returned the amount remaining; this has
been removed in lieu of exposing the existing `vm.Contract.UseGas()`
method via the `vm.PrecompileEnvironment`. A new `legacy` package wraps
the old signature and converts it to a new one so `ava-labs/coreth`
doesn't need to be refactored.
```go
func oldPrecompile(env vm.PrecompileEnvironment, input []byte, gas uint64) ([]byte, uint64, error) {
// ...
if err != nil {
return nil, gas - gasCost, err // pattern susceptible to bugs; should it be `nil, gas, err` ?
}
// ...
return output, gas - gasCost, nil
}
func newPrecompile(env vm.PrecompileEnvironment, input []byte) ([]byte, error) {
// The original `gas` argument is still available as `env.Gas()`
// ...
if !env.UseGas(gasCost) { // an explicit point at which gas is consumed
return nil, vm.ErrOutOfGas
}
// ...
if err != nil {
return nil, err
}
// ...
return output, nil
}
```
## How this was tested
Existing unit test modified to use the `legacy` adaptor.
---------
Signed-off-by: Arran Schlosberg <519948+ARR4N@users.noreply.github.com>
Co-authored-by: Quentin McGaw <quentin.mcgaw@gmail.com>
## Why this should be merged
Fixes tracing when a stateful precompile calls another contract that
itself accesses storage.
## How this works
The pre-state tracer from `eth/tracers/native` doesn't implement
`CaptureEnter()` (entry of a new context), instead relying on
`CaptureState()` (per-opcode tracing) to detect that a new contract has
been entered. In doing so, it [maintains an
invariant](cb7eb89341/eth/tracers/native/prestate.go (L160))
that is expected when `CaptureState(vm.SLOAD, ...)` is called—breaking
the invariant results in a panic due to a nil map.
The fix involves (a) maintaining the invariant as part of
`CaptureEnter()` (previously a no-op); and (b) calling said method
inside `vm.PrecompileEnvironment.Call()`. The latter has the added
benefit of properly handling all tracing involving an outbound call from
precompiles.
## How this was tested
New integration test demonstrates that the tracer can log the retrieved
storage value.
---------
Co-authored-by: Darioush Jalali <darioush.jalali@avalabs.org>
* fix: `vm.WithUNSAFECallerAddressProxying` under `DELEGATECALL`
* test: `vm.WithUNSAFECallerAddressProxying()` effect on outgoing caller addr
* chore: mark `eth/tracers/js` test flaky
* feat: `vm.PrecompileEnvironment.IncomingCallType()`
* chore: minor documentation edit
* doc: `PrecompileEnvironment` example for determining actual caller
* chore: placate the linter
* refactor!: `RulesHooks.CanCreateContract()` via `defer`
`TestCanCreateContract` is unchanged and merely moved to the appropriate file.
* feat!: `RulesHooks.CanCreateContract()` accepts and returns gas
* chore: move `TestCanCreateContract` to original file
Simplifies code review
* chore: pacify linter
* refactor!: revert to non-deferred call (not at start)
* chore: `golangci-lint` CI workflow
* fix: make `golangci-lint` happy
* chore: bump `actions/{checkout,setup-go}` versions
* chore: overhaul `.golanci.yml` config
* fix: all linter issues
* chore: exclude non-libevm linters + change deprecated option
* fix: add overflow check in example
* fix: try again; different local version?
* chore: this is trying my patience
* chore: enable `gci` and fix ordering
* chore: mark `ethclient/gethclient` test as flaky
* chore: mark `eth/catalyst` test as flaky
* feat: pseudo-generic extra payloads in `params.ChainConfig` and `params.Rules`
* feat: `params.ExtraPayloadGetter` for end-user type safety
* refactor: payloads only available through `params.ExtraPayloadGetter`
* chore: make `libevm/examples/extraparams` a `params` testable example
* doc: `libevm/pseudo` package comments and improved readability
* doc: `params.*Extra*` comments and improved readability
* doc: `params.ExtraPayloadGetter` comments and improved readability
* doc: `params/config.libevm_test.go` comments and improved readability
* refactor: simplify `params.ChainConfig.UnmarshalJSON()`
* refactor: abstract new/nil-pointer creation into `pseudo.Constructor`s
* feat: precompile override via `params.Extras` hooks
* doc: flesh out `PrecompileOverride()` in example
* doc: complete commentary and improve readability
* refactor: `ChainConfig.Hooks()` + `Rules` equivalent
* chore: rename precompiles test file in keeping with geth equivalent
* feat: stateful precompiles + allowlist hooks
The allowlist hooks are included in this commit because they allow for the same functionality as stateful precompiles in `ava-labs/coreth` and `ava-labs/subnet-evm`.
* fix: `StateTransition.canExecuteTransaction()` used `msg.From` instead of `To`
* test: `params.RulesHooks.CanCreateContract` integration
* test: `params.RulesHooks.CanExecuteTransaction` integration
* test: `vm.NewStatefulPrecompile()` integration
* refactor: simplify test of `CanCreateContract`
* refactor: abstract generation of random `Address`/`Hash` values
* doc: full documentation + readability refactoring/renaming
* fix: remove circular dependency in tests
