Commit Graph

62 Commits

Author SHA1 Message Date
Jamie Lokier 834449d943
Assembler: Second asmSetupComputation, calls the first
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>
2021-05-04 01:03:55 +01:00
Jamie Lokier 5728491d60
Assembler: First asmSetupComputation to support asmCallEvm
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>
2021-05-04 01:03:55 +01:00
Jamie Lokier cc7307186d
RPC: Don't export rpcSetupComputation
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>
2021-05-04 01:00:51 +01:00
Jamie Lokier c7e1cb61ee
Transaction: Make transaction validation use new function txCallEvm
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>
2021-05-04 00:56:03 +01:00
Jamie Lokier 4187eb1959
Transaction: Prepare txRefundGas to support txCallEvm
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>
2021-05-03 19:51:20 +01:00
Jamie Lokier 52fd8b8129
Transaction: Prepare txSetupComputation to support txCallEvm
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>
2021-05-03 19:51:20 +01:00
Jamie Lokier 9a5e0d2833
RPC: Change rpcEstimateGas to use the EVM without a fake transaction
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>
2021-05-03 16:41:37 +01:00
Jamie Lokier 76c4c72abb
RPC: Prepare rpcSetupComputation to support estimateGas
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>
2021-05-03 16:41:33 +01:00
Jamie Lokier 6dd14e4f4f
GraphQL: Move EVM-calling function makeCall to rpcMakeCall
`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>
2021-05-03 10:59:13 +01:00
Jamie Lokier 8bda81496a
RPC: Move EVM-calling function estimateGas to rpcEstimateGas
`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>
2021-05-03 10:59:10 +01:00
Jamie Lokier 2732af99eb
RPC: Move EVM-calling function doCall to rpcDoCall
`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>
2021-05-03 10:59:07 +01:00
Jamie Lokier 7c3b7ab7a8
RPC: Gather EVM-calling functions to one place; rpcSetupComputation
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>
2021-05-03 10:59:05 +01:00