There are currently six entry points to running an EVM computation, all with
slightly different parameters, and expecting slightly different EVM behaviours.
First step in merging them is a common `setupComputation` that replaces all
the different `*...SetupComputation` functions.
This uses the `TransactionHost` type because it's a step towards using that
type for all EVM calls using only EVMC. For now an EVMC message is created
then translated to EVM-internal `Message`. It is done this way to build up
the new interface in stages where all tests pass at each stage.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
`TransactionHost` represents the interface to the EVM from the application once
we've fully transitioned to EVMC. It represents a managed EVM call, and the
"EVMC host" side of the host<->EVM boundary.
This holds transaction state which sits outside the EVM, but a pointer to this
is passed around by the EVM as _opaque_ type `evmc_host_context`.
To the EVM, this offers "host services", which manage account state that the
EVM cannot do, such as balance transfers, call costs, storage, logs, gas
refunds, nested calls and new contract addresses. The EVM has no direct access
to the account state database or network; it's all via "host services".
To the application (host side), this object represents a managed EVM call, with
inputs, a method to run, outputs, hidden transaction state, and later async
scheduling. It is to replace `Computation` on the application side, while
`Computation` will remain but just be for the EVM side.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Each place in `call_evm` that sets up an EVM call calculates the new contract
address for contract creations. But it's redundant, because `newComputation`
ignores the provided value and does the calculation again.
Remove the unused address calculation.
This is also a step to merging different entry points and EVMC. This change
ends up with the same value in both `msg.contractAddress` and `msg.codeAddress`
for every entry point, and this is good because it matches the EVMC message
structure, where they are replaced by only one value called `msg.destination`
Signed-off-by: Jamie Lokier <jamie@shareable.org>
`c.executeOpcodes` is called by some JSON fixture tests. These tests bypass
some of the setup and return, and because of this call, continuations aren't
processed either. Opcodes that use continuations will behave incorrectly.
The opcodes used in these particular tests don't use continuations currently,
so just add some assertions to verify this remains the case.
This is only used by local tests, and the call to `c.executeOpcodes` will be
replaced by the common entry point (that handles things like this correctly in
all cases) so we don't need to spend more time on this.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Move the EVM setup and call in precompile tests to `fixtureCallEvm` in
`call_evm`. Extra return values needed for testing are returned specially, and
the convention for reporting gas used is changed to match `asmCallEvm`.
Although the precompile tests used `execPrecompiles` before, `executeOpcodes`
does perfectly well as a substitute, allowing `fixtureCallEvm` to be shared.
_Significantly, this patch also makes `Computation` more or less an internal
type of the EVM now._
Nothing outside the EVM (except `call_evm`) needs access any more to
`Computation`, `execComputation`, `executeOpcodes` or `execPrecompiles`.
Many imports can be trimmed, some files removed, and EVMC is much closer.
(As a bonus, the functions in `call_evm` reveal what capabilities parts of the
program have needed over time, makes certain bugs and inconsistencies clearer,
and suggests how to refactor into a more useful shared entry point.)
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Allow the fork to be specified consistently through an `option[Fork]` instead
of varying inconsistencies depending on which call. When fork is not
specified, the `BaseVMState` code picks the correct fork by default for the
block number and chain.
This change actually deletes code, because a number of functions (RPC etc) had
redundant code to pick the fork, which always resolved to same as default.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Move the EVM setup and call in fixtures "vm json tests" to new function
`fixtureCallEvm` in `call_evm`. Extra return values needed for testing are
returned specially.
This entry point is different from all other `..CallEvm` type functions,
because it uses `executeOpcodes` instead of `execComputation`, so it doesn't
update the account balance or nonce on entry and exit from the EVM.
The new code is a bit redundant and simplistic intentionally, as the purpose is
to move functionality to `call_evm` with high confidence nothing really
changed. The calls will be jointly refactored afterwards to merge differences.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
In the `text_vm_json` ("fixtures") test code, there is another variant of
`rpcSetupComputation` and `txSetupComputation` with slightly different
paremeters. The similarity is obvious.
It is a special setup for testing, though, as it requires slightly different
parameters.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
usually, there is always a sender around `getRecipient` call.
no need to recalculate sender. and more important, in some of
JSON-RPC/GraphQL call, the sender is come from `rpcCallData`,
not from `tx.getSender`. or in ohter situation when the tx is
an unsigned tx, without `r,s,v` fields to calculate sender.
Move the EVM setup and call in `macro_assembler` (`runVM`) entirely to new
function `asmCallEvm` in `call_evm`. Extra return values needed for
testing are returned specially from `asmCallEvm`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
The second `asmSetupComputation looks up state by block number and preceding
block number, modifies the first transaction with code for testing, and uses
some parts of that transaction to setup an an EVM test.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
In the `macro_assembler` test code, `initComputation` is another variant of
`rpcSetupComputation` and `txSetupComputation` with slightly different
paremeters. The similarity is obvious.
It is a special setup for testing, though, as it requires a contract-creation
transaction for parameters, but sets up a `CALL` execution not `CREATE`.
Gather this into `call_evm`: `initComputation` -> `asmSetupComputation`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
The point of the `call_vm` exercise is to allow `Computation` to become an
internal type of the EVM, not used as API by the rest of the program. So
`rpcSetupComputation` should be private. It was left exported by mistake.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Split out and move the EVM setup and call in `processTransaction` to
`call_evm`. This is the last part of the main program which calls the EVM
to be moved. (There's still test code.)
While we're here, move the EIP2929 access list setup too, as the similarity
to `rpcInitialAccessListEIP2929` is obvious.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
There's only one call left to `refundGas(Transaction, ...)`, and the
similarity to the tail of `rpcEstimateGas` is obvious.
Gather this into `call_evm`: `refundGas` -> `txRefundGas`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
After recent changes, there's only one call left to `setupComputation`, and
it's just a variant like `rpcSetupComputation` but for transaction processing.
The similarity to `rpcSetupComputation` is obvious.
Gather this into `call_evm`: `setupComputation` -> `txSetupComputation`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Change `rpcEstimateGas` to setup and execute a computation directly, in a
similar way to `rpcDoCall` and `rpcMakeCall`, instead of constructing a fake
transaction and then validating it.
This patch does not (or should not) change any behaviour.
Although this looks a bit messy as it duplicates parts of `validateTransaction`
and `processTransaction`, proc names have been used to hopefully keep the
meanings clear, and it's just a stepping stone as those transaction functions
will be changed next. Also the behaviour of RPC `estimateGas` may not be
correct (although this patch is careful not to change it), so it's good to make
it explicit so we can see how it differs from other RPCs.
Doing this change exposed some interesting behaviour differences between the
`call` RPC and `estimateGas` RPC, which may be bugs, or may be intentional.
These differences are now obvious and explicit.
The unclear areas are not well documented by any of the clients, even Infura
which says a bit more than the others. So to find out if they are intended,
we'll have to run tests against other Ethereum services.
Guessing, on the face of it, it looks likely that RPC `call` should:
- Setup EIP2929 access lists
- Account for intrinsic gas (maybe not because zero-gas transactions are ok)
And it looks likely that RPC `estimateGas` should:
- Not return zero when an account has insufficient balance
- Maybe use a different gas cost estimate when one isn't supplied in the RPC
Signed-off-by: Jamie Lokier <jamie@shareable.org>
The RPC `estimateGas` behaves differently from RPC `call` in a number of ways.
These differences may be bugs due to `rpcEstimateGas` calling the EVM in a very
different way than `rpcDoCall`, or they may be intentional. To be sure, we'll
need to test behaviour with Geth, Infura etc to find out (their documentation
isn't enough.) For now, though, we'll keep the same behaviour as we always had.
`rpcEstimateGas` cannot use `rpcSetupComputation` as it is, because
`estimateGas` accounts for "intrinsic gas", and `call` does not.
This patch changes `rpcSetupComputation` to accomodate both behaviours.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
`makeCall` used by GraphQL is another way to setup and call the EVM.
Move it to `transaction/call_evm`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
`estimateGas` used by JSON-RPC is another way to setup and call the EVM,
also used by GraphQL. Move it to `transaction/call_evm`.
This function has too much direct knowledge of details that shouldn't be used
outside transaction handling code, details we need to change when changing the
db and transaction memory layer.
Moving this one exposed quite a bit of abstraction leakage, as it calls
directly to the hexary trie db around `processTransaction`.
It looks like the _intended_ functionality of `estimateGas` is similar to
`rpcDoCall` with the only real difference being to not store the final state.
It looks like the extra stuff in `estimateGas` compared with `doCall` is a
messy workaround for computation not exposing the right API ("don't save final
state") for RPC to use.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
`doCall` used by JSON-RPC is another way to setup and call the EVM.
Move it to `transaction/call_evm`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Start gathering the functions that call the EVM into one place,
`transaction/call_evm.nim`.
This is first of a series of changes to gather all ways the EVM is called to
one place. Duplicate, slightly different setup functions have accumulated over
time, each with some knowledge of EVM internals. When they are brought
together, these methods will be changed to use a single entry point to the EVM,
allowing the entry point to be refactored, EVMC to be completed, and async
concurrency to be implemented on top. This also simplifies the callers.
First, a helper function used by RPC and GraphQL to make EVM calls without
permanently modifying the account state. `setupComputation` ->
`rpcSetupComputation`.
Signed-off-by: Jamie Lokier <jamie@shareable.org>
Jamie Lokier
jangko