Commit Graph

111 Commits

Author SHA1 Message Date
jangko 26620eb672
EVM embrace more EVMC types
Also embed evmc_status_code to computation.error, and make
the tracer produce cleaner output. No more "Revert opcode executed"
error message. We can distinguish error code between REVERT
and FAILURE in a more cleaner way.
2023-08-28 21:36:23 +07:00
andri lim 91704cd3ae
Add current computation to each EVM tracer interface (#1712) 2023-08-25 16:07:20 +07:00
jangko 467e6fffa6
Implement EIP-6780: SELFDESTRUCT only in same transaction 2023-08-18 10:22:34 +07:00
jangko dd9e181acc
EIP-1153: completing transient storage on EVMC side 2023-08-18 10:19:34 +07:00
andri lim bdaeedb09f
rename data gas to blob gas (#1659)
* rename data gas to blob gas

* bump more submodules
* extend evmc tx_context with EIP-4844 blob_hashes
2023-08-04 19:43:30 +07:00
Jordan Hrycaj 221e6c9e2f
Unified database frontend integration (#1670)
* Nimbus folder environment update

details:
* Integrated `CoreDbRef` for the sources in the `nimbus` sub-folder.
* The `nimbus` program does not compile yet as it needs the updates
  in the parallel `stateless` sub-folder.

* Stateless environment update

details:
* Integrated `CoreDbRef` for the sources in the `stateless` sub-folder.
* The `nimbus` program compiles now.

* Premix environment update

details:
* Integrated `CoreDbRef` for the sources in the `premix` sub-folder.

* Fluffy environment update

details:
* Integrated `CoreDbRef` for the sources in the `fluffy` sub-folder.

* Tools environment update

details:
* Integrated `CoreDbRef` for the sources in the `tools` sub-folder.

* Nodocker environment update

details:
* Integrated `CoreDbRef` for the sources in the
  `hive_integration/nodocker` sub-folder.

* Tests environment update

details:
* Integrated `CoreDbRef` for the sources in the `tests` sub-folder.
* The unit tests compile and run cleanly now.

* Generalise `CoreDbRef` to any `select_backend` supported database

why:
  Generalisation was just missed due to overcoming some compiler oddity
  which was tied to rocksdb for testing.

* Suppress compiler warning for `newChainDB()`

why:
  Warning was added to this function which must be wrapped so that
  any `CatchableError` is re-raised as `Defect`.

* Split off persistent `CoreDbRef` constructor into separate file

why:
  This allows to compile a memory only database version without linking
  the backend library.

* Use memory `CoreDbRef` database by default

detail:
 Persistent DB constructor needs to import `db/core_db/persistent

why:
 Most tests use memory DB anyway. This avoids linking `-lrocksdb` or
 any other backend by default.

* fix `toLegacyBackend()` availability check

why:
  got garbled after memory/persistent split.

* Clarify raw access to MPT for snap sync handler

why:
  Logically, `kvt` is not the raw access for the hexary trie (although
  this holds for the legacy database)
2023-08-04 12:10:09 +01:00
jangko 4d207e49ce
Implement plugable EVM tracer
available tracers:
- Legacy tracer
- new Json tracer
2023-08-03 16:45:39 +07:00
jangko 3aff8d0d61
fix EIP-4844 bugs in genesis, evmstate and blobFee 2023-07-21 06:34:56 +07:00
andri lim 26a8759c34
implementation of EIP-4844: Shard Blob Transactions (#1440)
* EIP-4844: add pointEvaluation precompiled contract

* EIP-4844: validate transaction and block header

* EIP-4844: implement DataHash Op Code

* EIP-4844: txPool support excessDataGas calculation

* EIP-4844: make sure tx produce correct txHash

* EIP-4844: node should not automatically broadcast blob tx to it's peers

* EIP-4844: add test cases

* EIP-4844: add EIP-4844 support to t8n tool

* EIP-4844: update nim-eth to branch eip-4844

* fix t8n transaction decoding

* add t8n test data

* EIP-4844: fix blobHash opcode

* disable blobHash test when evmc_enable
2023-06-24 20:56:44 +07:00
jangko 4e332868b7
reduce compiler warnings 2023-05-16 11:15:10 +07:00
Kim De Mey 408394a2bd
Bump nim-eth and remove unneeded Defect raises (#1575) 2023-05-10 18:04:35 +02:00
Adam Spitz c58d83efd5
More work on stateless mode (#1535)
* Reviving more of the code for stateless mode.

* Made asyncProcessTransaction.

* More work on stateless mode.
2023-04-12 08:39:11 -04:00
jangko 2a3c67b4be
refactor touched accounts, selfdestruct, and log
simplify EVM and delegete those things to accounts cache.
also no more manual state clearing, accounts cache will be
responsible for both collecting touched account and perform
state clearing.
2023-03-21 08:14:06 +07:00
jangko 633f135c72
align accounts cache with EIP158/161
Some nomenclature used in accounts cache are not what described
in EIP158/161, therefore causing confusion and introduce bugs.
Now it should be fixed.
2023-03-18 18:13:06 +07:00
Adam Spitz 8d9b2522ea
More on withdrawals (#1508)
* Gwei conversion should use u256 because u64 can overflow.

* Make withdrawals follow the EIP-158 state-clearing rules.

(i.e. Empty accounts should be deleted.)

* Allow the zero address in normalizeNumber.

(Necessary for one of the new withdrawals-related tests.)

* Another fix with a withdrawals-related test.
2023-03-17 14:16:24 -04:00
Adam Spitz fad3ed64cf
Time based forking (#1465)
* Refactoring in preparation for time-based forking.

* Timestamp-based hard-fork-transition.

* Workaround SideEffect issue / compiler bug for both failing locations in Portal history code

---------

Co-authored-by: kdeme <kim.demey@gmail.com>
2023-02-16 12:40:07 +01:00
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
Jordan Hrycaj 6b9f3c9ac5
Silence compiler gossip after nim upgrade cont1 (#1455)
* Silence some compiler gossip -- part 5, common

details:
  Mostly removing redundant imports and `Defect` tracer after switch
  to nim 1.6

* Silence some compiler gossip -- part 6, db, rpc, utils

details:
  Mostly removing redundant imports and `Defect` tracer after switch
  to nim 1.6

* Silence some compiler gossip -- part 7, randomly collected source files

details:
  Mostly removing redundant imports and `Defect` tracer after switch
  to nim 1.6

* Silence some compiler gossip -- part 8, assorted tests

details:
  Mostly removing redundant imports and `Defect` tracer after switch
  to nim 1.6

* Clique update

why:
  More impossible exceptions (undoes temporary fix from previous PR)
2023-01-31 01:32:17 +00:00
Adam Spitz 4bf4aeba94
Some of Shanghai: EIP-3651, EIP-3855, EIP-3860 (#1406)
* EIP-3651: Warm COINBASE

* EIP-3855: PUSH0 instruction

* EIP-3860: Limit and meter initcode
2023-01-04 08:11:33 -05:00
jangko 2b5195c526
add geth compatibility flag to emvstate tool and transaction tracer 2022-12-14 21:52:43 +07:00
jangko 94a94c5b65 implement better hardfork management 2022-12-02 13:51:42 +07:00
Adam Spitz e040e2671a
Added basic async capabilities for vm2. (#1260)
* Added basic async capabilities for vm2.

This is a whole new Git branch, not the same one as last time
(https://github.com/status-im/nimbus-eth1/pull/1250) - there wasn't
much worth salvaging. Main differences:

I didn't do the "each opcode has to specify an async handler" junk
that I put in last time. Instead, in oph_memory.nim you can see
sloadOp calling asyncChainTo and passing in an async operation.
That async operation is then run by the execCallOrCreate (or
asyncExecCallOrCreate) code in interpreter_dispatch.nim.

In the test code, the (previously existing) macro called "assembler"
now allows you to add a section called "initialStorage", specifying
fake data to be used by the EVM computation run by that test. (In
the long run we'll obviously want to write tests that for-real use
the JSON-RPC API to asynchronously fetch data; for now, this was
just an expedient way to write a basic unit test that exercises the
async-EVM code pathway.)

There's also a new macro called "concurrentAssemblers" that allows
you to write a test that runs multiple assemblers concurrently (and
then waits for them all to finish). There's one example test using
this, in test_op_memory_lazy.nim, though you can't actually see it
doing so unless you uncomment some echo statements in
async_operations.nim (in which case you can see the two concurrently
running EVM computations each printing out what they're doing, and
you'll see that they interleave).

A question: is it possible to make EVMC work asynchronously? (For
now, this code compiles and "make test" passes even if ENABLE_EVMC
is turned on, but it doesn't actually work asynchronously, it just
falls back on doing the usual synchronous EVMC thing. See
FIXME-asyncAndEvmc.)

* Moved the AsyncOperationFactory to the BaseVMState object.

* Made the AsyncOperationFactory into a table of fn pointers.

Also ditched the plain-data Vm2AsyncOperation type; it wasn't
really serving much purpose. Instead, the pendingAsyncOperation
field directly contains the Future.

* Removed the hasStorage idea.

It's not the right solution to the "how do we know whether we
still need to fetch the storage value or not?" problem. I
haven't implemented the right solution yet, but at least
we're better off not putting in a wrong one.

* Added/modified/removed some comments.

(Based on feedback on the PR.)

* Removed the waitFor from execCallOrCreate.

There was some back-and-forth in the PR regarding whether nested
waitFor calls are acceptable:

https://github.com/status-im/nimbus-eth1/pull/1260#discussion_r998587449

The eventual decision was to just change the waitFor to a doAssert
(since we probably won't want this extra functionality when running
synchronously anyway) to make sure that the Future is already
finished.
2022-11-01 11:35:46 -04:00
jangko 4b142ac52d
upgrade evmc to v10.0.0
fixes #1172, fixes #950
2022-10-03 16:38:32 +07:00
jangko a4678a041d
wire evmc to vm2 and drop legacy vm
fixes #445, #1172
2022-09-26 15:16:28 +07:00
Jacek Sieka c2ed731fa5
eth: adapt to smaller eth_types (#1210) 2022-09-03 20:15:35 +02:00
Jordan Hrycaj 58e0543920
Squashed snap-sync-preview patch (#1076)
* Squashed snap-sync-preview patch

why:
  Providing end results makes it easier to have an overview.

  Collected patch set comments are available as nimbus/sync/ChangeLog.md
  in chronological order, oldest first.

* Removed some cruft and obsolete imports, normalised logging
2022-05-09 15:04:48 +01:00
jangko f2f204293e
first step into styleCheck fixes 2022-04-14 08:39:50 +07:00
jangko 28cdfcaf6b
fix EIP-4399 'random' opcode
- fix previous implementation of EIP-4399
- now `random` opcode can be used with evmc_enabled
2022-02-08 20:23:40 +07:00
jangko 71aa7e4b5c EIP-4399 implementation of nim-vm
what's new:
- `RANDOM` OPCODE
- `random` field of BlockHeader(previously `mixDigest`)
- `PostMerge` temporary name
2022-02-01 18:11:14 +02:00
Jordan Hrycaj 261c0b51a7
Redesign of BaseVMState descriptor (#923)
* Redesign of BaseVMState descriptor

why:
  BaseVMState provides an environment for executing transactions. The
  current descriptor also provides data that cannot generally be known
  within the execution environment, e.g. the total gasUsed which is
  available not before after all transactions have finished.

  Also, the BaseVMState constructor has been replaced by a constructor
  that does not need pre-initialised input of the account database.

also:
  Previous constructor and some fields are provided with a deprecated
  annotation (producing a lot of noise.)

* Replace legacy directives in production sources

* Replace legacy directives in unit test sources

* fix CI (missing premix update)

* Remove legacy directives

* chase CI problem

* rebased

* Re-introduce 'AccountsCache' constructor optimisation for 'BaseVmState' re-initialisation

why:
  Constructing a new 'AccountsCache' descriptor can be avoided sometimes
  when the current state root is properly positioned already. Such a
  feature existed already as the update function 'initStateDB()' for the
  'BaseChanDB' where the accounts cache was linked into this desctiptor.

  The function 'initStateDB()' was removed and re-implemented into the
  'BaseVmState' constructor without optimisation. The old version was of
  restricted use as a wrong accounts cache state would unconditionally
  throw an exception rather than conceptually ask for a remedy.

  The optimised 'BaseVmState' re-initialisation has been implemented for
  the 'persistBlocks()' function.

also:
  moved some test helpers to 'test/replay' folder

* Remove unused & undocumented fields from Chain descriptor

why:
  Reduces attack surface in general & improves reading the code.
2022-01-18 16:19:32 +00:00
Jamie Lokier 6a7803a9e4
EVMC: Improve `--evm`, remove it in non-EVMC builds, change imports
- Remove the `--evm` option on non-EVMC builds.
  `when` around an option doesn't work with confutils; it fails to compile.
  Workaround that by setting the `ignore` pragma on EVMC-specific options.
  (Thanks @jangko for that new pragma).  I prefer this to a solution which
  moves the whole option's pragma elsewhere, especially if we add more options.

- Improve the help text, so that it shows the standard library extension on
  each target platform (or none if on another platform).

- Undo b3f21bf4 "add missing evmc_enabled conditional compilation in
  evmc_dynamic_loader".  Move the conditional to `nimbus.nim`, and take more
  care there to only use the loader function in EVMC builds.

  It's ok to just not include this EVMC-only module (like some other EVMC
  modules), rather than making the module itself a bit broken: Without this
  change, it references a function that's not imported or linked to, and it
  only links because there is no call sequence reaching that function.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-12-14 15:51:09 +00:00
jangko b3f21bf40c
add missing evmc_enabled conditional compilation in evmc_dynamic_loader 2021-12-12 16:32:13 +07:00
Jamie Lokier cf49b8d4fc
EVMC: Option `--evm`, load third-party EVM as a shared library
This patch adds:

- Load and use a third-party EVM in a shared library, instead of Nimbus EVM.
- New option `--evm` to specify which library to load.
- The library and this loader conforms to the [EVMC]
  (https://evmc.ethereum.org/) 9.x specification.

Any third-party EVM which is compatible with EVMC version 9.x and supports EVM1
contract code will be accepted.  The operating system's shared library format
applies.  These are `.so*` files on Linux, `.dll` files on Windows and `.dylib`
files on Mac.

The alternative EVM can be selected in two ways:

- Nimbus command line option `--evm:<path>`.
- Environment variable `NIMBUS_EVM=<path>`.

The reason for an environment variable is this allows all the test programs to
run with a third-party EVM as well.  Some don't parse command line options.

There are some limitations to be aware of:

- The third-party EVM must use EVMC version 9.x, no other major version.
  EVMC 9.x supports EIP-1559 / London fork and older transactions.

- Nested `*CALL` and `CREATE*` operations don't use the third-party EVM yet.
  These call the built-in Nimbus EVM.  This mixing of different EVMs between
  levels is explicitly allowed in specs, so there is no problem doing it.

- The third-party EVM doesn't need to support precompiles, because those are
  nested calls, which use the built-in Nimbus EVM.

- Third-party EVMs execute contracts correctly, but fail the final `rootHash`
  match.  The reason is that some account state changes, which are correct, are
  currently inside the Nimbus EVM and need to be moved to EVMC host logic.
  *This is a known work in progress*.  The EVM execution itself is fine.

Test results using "evmone" third-party EVM:

- [evmone](https://github.com/ethereum/evmone) has been tested.  Only on
  Linux but it "should" work on Windows and Mac equally well.

- [Version 0.8.1](https://github.com/ethereum/evmone/releases/tag/v0.8.1) was
  used because it is compatible with EVMC 9.x, which is required for the
  EIP-1559 / London fork, which Nimbus supports.  Version 0.8.0 could be used
  but it looks like an important bug was fixed in 0.8.1.

- evmone runs fine and the trace output looks good.  The calls and arguments
  are the same as the built-in Nimbus EVM for tests that have been checked
  manually, except evmone skips some calls that can be safely skipped.

- The final `rootHash` is incorrect, due to the *work in progress* mentioned
  above which is not part of the evmone execution.  Due to this, it's possible
  to try evmone and verify expected behaviours, which also validates our own
  EVMC implementation, but it can't be used as a full substitute yet.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-12-10 16:32:18 +00:00
Jamie Lokier 072934272b
Transaction: Map `evmc_result` back to `Computation` result
This missing part of EVMC processing allows third-party EVMs to work.

It fixes EVMC result processing (at the top-level of calls, not nested calls)
to use the EVMC result object, instead of reading so much internal state of the
Nimbus `Computation` object.

It has been tested by calling [`evmone`](https://github.com/ethereum/evmone)
and getting useful results with tracing enabled (`showTxCalls = true`).  It's
even able to run parts of the fixtures test suite.

There are other issues with account balances, etc that need to be worked on to
get the correct _final_ results, but the EVM execution is correct with this.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-12-10 16:27:53 +00:00
Jamie Lokier 6ef9bfd21b
EVMC: Byte-endian conversions for 256-bit numeric values
Perform byte-endian conversion for 256-bit numeric values, but not 256-bit
hashes.  These conversions are necessary for EVMC binary compatibility.

In new EVMC, all host-side conversions are explicit, calling `flip256`.

These conversions are performed in the EVMC "glue" code, which deals with the
binary interface, so the host services aren't aware of conversions.

We intend to skip these conversions when Nimbus host calls Nimbus EVM, even
when it's a shared library, using a negotiated EVMC extension.  But for now
we're focused on correctness and cross-validation with third party EVMs.

The overhead of endian conversion is not too high because most EVMC host calls
access the database anyway.  `getTxContext` does not, so the conversions from
that are cached here.  Also, well-optimised EVMs don't call it often.

It is arguable whether endian conversion should occur for storage slots (`key`).

In favour of no conversion: Slot keys are 32-byte blobs, and this is clear in
the EVMC definition where slot keys are `evmc_bytes32` (not `evmc_uint256be`),
meaning treating as a number is _not_ expected by EVMC.  Although they are
often small numbers, sometimes they are a hash from the contract code plus a
number.  Slot keys are hashed on the host side with Keccak256 before any
database calls, so the host side does not look at them numerically.

In favour of conversion: They are often small numbers and it is helpful to log
them as such, rather than a long string of zero digits with 1-2 non-zero.  The
representation in JSON has leading zeros removed, like a number rather than a
32-byte blob.  There is also an interesting space optimisation when the keys
are used unhashed in storage.

Nimbus currently treats slot keys on the host side as numbers, and the tests
pass when endian conversion is done.  So to remain consistent with other parts
of Nimbus we convert slot keys.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-12-10 16:23:27 +00:00
jangko 960539df81
unify evm call for both json-rpc and graphql
also fixes rpcEstimateGas for both of json-rpc and graphql
2021-10-31 12:24:40 +07:00
jangko baf508f6ae
move stateDB from VMState to chainDB
previously, every time the VMState was created, it will also create
new stateDB, and this action will nullify the advantages of cached accounts.

the new changes will conserve the accounts cache if the executed blocks
are contiguous. if not the stateDB need to be reinited.

this changes also allow rpcCallEvm and rpcEstimateGas executed properly
using current stateDB instead of creating new one each time they are called.
2021-10-28 18:57:08 +07:00
jangko d93a8bc4a1
make macro_assembler to use the same testEvmCall
it also allow the macro_assembler to write more test
of CALL and CREATE family which previously not possible
2021-10-14 15:10:12 +07:00
jangko 71273f2f4c
remove error field from evm CallResult 2021-10-14 15:10:12 +07:00
jangko 08f8652790
remove noTransfer field from evm CallParams 2021-10-14 15:10:11 +07:00
jangko eb2251ec37
simplify evm call of test_precompiles
first step towards evm call variation reduction
2021-10-14 15:10:11 +07:00
jangko 69f2a0f95a
config: replace stdlib parseOpt with nim-confutils
fixes #581
2021-09-18 17:34:46 +07:00
bmoo b09ad5cacb
code cleanup removed unused imports 2021-08-18 10:35:36 +07:00
Jamie Lokier 8fcd8354b1
EVMC: Use the same host interface for nested calls as top-level
Prior to this patch, top-level EVM executions and nested EVM executions did
their `getStorage` and other requests using a completely different set of host
functions.  It was just unfinished, to get top-level "new" EVMC working.

This finishes the job - it stops using the old methods.  Effect:

- Functionality added at the EVMC host level will be used by all EVM calls.
  (The target here is Beam Sync).

- The old set of functions are no longer used, so they can be removed.

- When EVMC host call tracing is enabled (`showTxCalls = true`), it traces
  the calls from nested EVM executions as well as top-level.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-08-17 17:18:26 +01:00
Jamie Lokier b783756ff3
EVMC: Make `hostInterface` a statically initialised global
We've been filling a "vtable"-like at run time, but it's not necessary.

The new object is a global `let x = evmc_host_interface(...)`, we assume it's
initialised before the first use, and we take its address with `.unsafeAddr`.

(If we use `ref evmc_host_interface`, Nim decides (correctly) that the
functions which use it aren't GC-safe because it's a global.)

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-08-17 17:18:26 +01:00
Jamie Lokier 3047c839dc
EVMC: Improve host call tracing and fix nested call C stack usage
This combines two things, a C stack usage change with EVM nested calls
via EVMC, and changes to host call tracing.

Feature-wise, the tracing is improved:

- Storage keys and values are make more sense.
- The message/result/context objects are shown with all relevant fields.
- `call` trace is split into entry/exit, so these can be shown around the
  called contract's operations, instead of only showing the `call` parameters
  after the nested call is finished.
- Nested calls are indented, which helps to highlight the flow.
- C stack usage considerably reduced in nested calls when more functionality
  is enabled (either tracing here, or other things to come).

This will seem like a minor patch, but C stack usage was the real motivation,
after plenty of time in the debugger.

Nobody cares about stack when `showTxCalls` (you can just use a big stack when
debugging).  But these subtle changes around the `call` path were found to be
necessary for passing all tests when the EVMC nested call code is completed,
and that's a prerequisite for many things: async EVM, dynamic EVM, Beam Sync,
and to fix https://github.com/status-im/nimbus-eth1/issues/345.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-08-12 07:48:56 +07:00
Jamie Lokier 74f53c7761
EVMC: Add missing EIP-2929 (Berlin) functions to EVMC host
The update for London (EIP-1559) in 1cdb30df ("bump nim-emvc with evmc revision
8.0.0 to 9.0.0") really bumped EVMC ABI version from 7.5 up to 9.

In other words, it skipped Berlin, going direct from Istanbul to London.

That was accompanied by EVMC changes in 05e9b891 ("EIP-3198: add baseFee op
code in nim-evm"), which added the API changes needed for London.

But the missing Berlin functions weren't added in the move to London.

As a result, our EVMC host became incompatible with Berlin, London, and really
all revisions of the ABI, and if a third party EVM was loaded, it crashed.

This commit adds the missing Berlin host support, and makes our ABI
binary-compatible with real EVMC again.

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-08-11 19:47:34 +07:00
Jamie Lokier 11f03a1846
Transaction: EVMC fix, `CREATE2` salt is a 256-bit blob not a number
This changes fixes a bug in `CREATE2` ops when used with EVMC.
Because it changes the salt type, it affects non-EVMC code as well.

The salt was passed through EVMC with the wrong byte order, although this went
unnoticed as the Nimbus host flipped the byte order before using it.

This was found when running Nimbus with third-party EVM,
["evmone"](https://github.com/ethereum/evmone).

There are different ways to remedy this.

If treated as a number, Nimbus EVM would byte-flip the value when calling EVMC,
then Nimbus host would flip the received value.  Finally, it would be flipped a
third time when generating the address in `generateSafeAddress`.  The first two
flips can be eliminated by negotiation (like other numbers), but there would
always be one flip.

As a bit pattern, Nimbus EVM would flip the same way it does when dealing with
hashes on the stack (e.g. with `getBlockHash`).  Nimbus host wouldn't flip at
all - and when using third-party EVMs there would be no flips in Nimbus.

Because this value is not for arithmetic, any bit pattern is valid, and there
shouldn't be any flips when using a third-party EVM, the bit-pattern
interpretation is favoured.  The only flip is done in Nimbus EVM (and might be
eliminated in an optimised version).

As suggested, we'll define a new "opaque 256 bits" type to hold this value.
(Similar to `Hash256`, but the salt isn't necessarily a hash.)

Signed-off-by: Jamie Lokier <jamie@shareable.org>
2021-08-05 10:35:52 +01:00
jangko 697b38b844
EIP-3529: Replace SSTORE_CLEARS_SCHEDULE in evmc host_service 2021-06-30 20:35:10 +07:00
jangko 472e4457e3
EIP-3529: Reduce the max gas refunded after a transaction
Previously max gas refunded was defined as gas_used div 2.
Here we name the constant 2 as MAX_REFUND_QUOTIENT and
change its value to 5.

The new equation will be: gas_used div MAX_REFUND_QUOTIENT
2021-06-29 07:37:17 +07:00