This adds a check to verify that a sender-account does not have code, which means that the codehash is either `emptyCodeHash` _OR_ not present. The latter occurs IFF the sender did not previously exist, a situation which can only occur with zero cost gasprices.
This commit changes the behavior of BitCurve.Add to be more inline
with btcd. It fixes two different bugs:
1) When adding a point at infinity to another point, the other point
should be returned. While this is undefined behavior, it is better
to be more inline with the go standard library.
Thus (0,0) + (a, b) = (a,b)
2) Adding the same point to itself produced the point at infinity.
This is incorrect, now doubleJacobian is used to correctly calculate it.
Thus (a,b) + (a,b) == 2* (a,b) and not (0,0) anymore.
The change also adds a differential fuzzer for Add, testing it against btcd.
Co-authored-by: Felix Lange <fjl@twurst.com>
This is the initial implementation of EIP-1559 in packages core/types and core.
Mining, RPC, etc. will be added in subsequent commits.
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: lightclient@protonmail.com <lightclient@protonmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
* eth/protocols/snap: generate storage trie from full dirty snap data
* eth/protocols/snap: get rid of some more dead code
* eth/protocols/snap: less frequent logs, also log during trie generation
* eth/protocols/snap: implement dirty account range stack-hashing
* eth/protocols/snap: don't loop on account trie generation
* eth/protocols/snap: fix account format in trie
* core, eth, ethdb: glue snap packets together, but not chunks
* eth/protocols/snap: print completion log for snap phase
* eth/protocols/snap: extended tests
* eth/protocols/snap: make testcase pass
* eth/protocols/snap: fix account stacktrie commit without defer
* ethdb: fix key counts on reset
* eth/protocols: fix typos
* eth/protocols/snap: make better use of delivered data (#44)
* eth/protocols/snap: make better use of delivered data
* squashme
* eth/protocols/snap: reduce chunking
* squashme
* eth/protocols/snap: reduce chunking further
* eth/protocols/snap: break out hash range calculations
* eth/protocols/snap: use sort.Search instead of looping
* eth/protocols/snap: prevent crash on storage response with no keys
* eth/protocols/snap: nitpicks all around
* eth/protocols/snap: clear heal need on 1-chunk storage completion
* eth/protocols/snap: fix range chunker, add tests
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
* trie: fix test API error
* eth/protocols/snap: fix some further liter issues
* eth/protocols/snap: fix accidental batch reuse
Co-authored-by: Martin Holst Swende <martin@swende.se>
The oss-fuzz fuzzer has been reporting some failing testcases for les. They're all spurious, and cannot reliably be reproduced. However, running them showed that there was a goroutine leak: the tests created a lot of new clients, which started an exec queue that was never torn down.
This PR fixes the goroutine leak, and also a log message which was erroneously formatted.
This updates the consensus tests to commit 31d6630 and
adds support for access list transactions in the test runner.
Co-authored-by: Martin Holst Swende <martin@swende.se>
This adds support for EIP-2718 typed transactions as well as EIP-2930
access list transactions (tx type 1). These EIPs are scheduled for the
Berlin fork.
There very few changes to existing APIs in core/types, and several new APIs
to deal with access list transactions. In particular, there are two new
constructor functions for transactions: types.NewTx and types.SignNewTx.
Since the canonical encoding of typed transactions is not RLP-compatible,
Transaction now has new methods for encoding and decoding: MarshalBinary
and UnmarshalBinary.
The existing EIP-155 signer does not support the new transaction types.
All code dealing with transaction signatures should be updated to use the
newer EIP-2930 signer. To make this easier for future updates, we have
added new constructor functions for types.Signer: types.LatestSigner and
types.LatestSignerForChainID.
This change also adds support for the YoloV3 testnet.
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Ryan Schneider <ryanleeschneider@gmail.com>
* les: refactored server handler
* tests/fuzzers/les: add fuzzer for les server handler
* tests, les: update les fuzzer
tests: update les fuzzer
tests/fuzzer/les: release resources
tests/fuzzer/les: pre-initialize all resources
* les: refactored server handler and fuzzer
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Removes the yolov2 definition, adds yolov3, including EIP-2565. This PR also disables some of the erroneously generated blockchain and statetests, and adds the new genesis hash + alloc for yolov3.
This PR disables the CLI switches for yolo, since it's not complete until we merge support for 2930.
This commit splits the eth package, separating the handling of eth and snap protocols. It also includes the capability to run snap sync (https://github.com/ethereum/devp2p/blob/master/caps/snap.md) , but does not enable it by default.
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>
This PR adds re-written difficulty calculators, which are based on uint256. It also adds a fuzzer + oss-fuzz integration for the new fuzzer. It does differential fuzzing between the new and old calculators.
Note: this PR does not actually enable the new calculators.
* added bls fuzzer
* crypto/bls12381: revert bls-changes, fixup fuzzer tests
* fuzzers: split bls fuzzing into 8 different units
* fuzzers/bls: remove (now stale) corpus
* crypto/bls12381: added blsfuzz corpus
* fuzzers/bls12381: fix the bls corpus
* fuzzers: fix oss-fuzz script
* tests/fuzzers: fixups on bls corpus
* test/fuzzers: remove leftover corpus
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
* all: core: split vm.Config into BlockConfig and TxConfig
* core: core/vm: reset EVM between tx in block instead of creating new
* core/vm: added docs
* trie: fix error in stacktrie not committing small roots
* fuzzers: make trie-fuzzer use correct returnvalues
* trie: improved tests
* tests/fuzzers: fuzzer for stacktrie vs regular trie
* test/fuzzers: make stacktrie fuzzer use 32-byte keys
* trie: fix error in stacktrie with small nodes
* trie: add (skipped) testcase for stacktrie
* tests/fuzzers: address review comments for stacktrie fuzzer
* trie: fix docs in stacktrie
* core/state/snapshot: introduce snapshot journal version
* core: update the disk layer in an atomic way
* core: persist the disk layer generator periodically
* core/state/snapshot: improve logging
* core/state/snapshot: forcibly ensure the legacy snapshot is matched
* core/state/snapshot: add debug logs
* core, tests: fix tests and special recovery case
* core: polish
* core: add more blockchain tests for snapshot recovery
* core/state: fix comment
* core: add recovery flag for snapshot
* core: add restart after start-after-crash tests
* core/rawdb: fix imports
* core: fix tests
* core: remove log
* core/state/snapshot: fix snapshot
* core: avoid callbacks in SetHead
* core: fix setHead cornercase where the threshold root has state
* core: small docs for the test cases
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
* whisper: remove whisper
* Update cmd/geth/config.go
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
* cmd/geth: warn on enabling whisper + remove more whisper deps
* mobile: remove all whisper references
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>
This PR implements the EVM state transition tool, which is intended
to be the replacement for our retesteth client implementation.
Documentation is present in the cmd/evm/README.md file.
Co-authored-by: Felix Lange <fjl@twurst.com>
* cmd, core, eth: init tx lookup in background
* core/rawdb: tiny log fixes to make it clearer what's happening
* core, eth: fix rebase errors
* core/rawdb: make reindexing less generic, but more optimal
* rlp: implement rlp list iterator
* core/rawdb: new implementation of tx indexing/unindex using generic tx iterator and hashing rlp-data
* core/rawdb, cmd/utils: fix review concerns
* cmd/utils: fix merge issue
* core/rawdb: add some log formatting polishes
Co-authored-by: rjl493456442 <garyrong0905@gmail.com>
Co-authored-by: Péter Szilágyi <peterke@gmail.com>
* core/state/snapshot: implement storage iterator
* core/state/snapshot, tests: implement helper function
* core/state/snapshot: fix storage issue
If an account is deleted in the tx_1 but recreated in the tx_2,
the it can happen that in this diff layer, both destructedSet
and storageData records this account. In this case, the storage
iterator should be able to iterate the slots belong to new account
but disable further iteration in deeper layers(belong to old account)
* core/state/snapshot: address peter and martin's comment
* core/state: address comments
* core/state/snapshot: fix test
* all: seperate consensus error and evm internal error
There are actually two types of error will be returned when
a tranaction/message call is executed: (a) consensus error
(b) evm internal error. The former should be converted to
a consensus issue, e.g. The sender doesn't enough asset to
purchase the gas it specifies. The latter is allowed since
evm itself is a blackbox and internal error is allowed to happen.
This PR emphasizes the difference by introducing a executionResult
structure. The evm error is embedded inside. So if any error
returned, it indicates consensus issue happens.
And also this PR improve the `EstimateGas` API to return the concrete
revert reason if the transaction always fails
* all: polish
* accounts/abi/bind/backends: add tests
* accounts/abi/bind/backends, internal: cleanup error message
* all: address comments
* core: fix lint
* accounts, core, eth, internal: address comments
* accounts, internal: resolve revert reason if possible
* accounts, internal: address comments
* cmd/utils: make goerli the default testnet
* cmd/geth: explicitly rename testnet to ropsten
* core: explicitly rename testnet to ropsten
* params: explicitly rename testnet to ropsten
* cmd: explicitly rename testnet to ropsten
* miner: explicitly rename testnet to ropsten
* mobile: allow for returning the goerli spec
* tests: explicitly rename testnet to ropsten
* docs: update readme to reflect changes to the default testnet
* mobile: allow for configuring goerli and rinkeby nodes
* cmd/geth: revert --testnet back to ropsten and mark as legacy
* cmd/util: mark --testnet flag as deprecated
* docs: update readme to properly reflect the 3 testnets
* cmd/utils: add an explicit deprecation warning on startup
* cmd/utils: swap goerli and ropsten in usage
* cmd/geth: swap goerli and ropsten in usage
* cmd/geth: if running a known preset, log it for convenience
* docs: improve readme on usage of ropsten's testnet datadir
* cmd/utils: check if legacy `testnet` datadir exists for ropsten
* cmd/geth: check for legacy testnet path in console command
* cmd/geth: use switch statement for complex conditions in main
* cmd/geth: move known preset log statement to the very top
* cmd/utils: create new ropsten configurations in the ropsten datadir
* cmd/utils: makedatadir should check for existing testnet dir
* cmd/geth: add legacy testnet flag to the copy db command
* cmd/geth: add legacy testnet flag to the inspect command
* update tests for istanbul
* tests: updated blockchaintests, see https://github.com/ethereum/tests/issues/637
* tests: update again, hopefully fixed this time
* tests: skip time consuming, run legacy tests
* tests: update again
* build: disable long-running tests on travis
* tests: fix formatting nits
* tests: I hate github's editor
Most of these changes are related to the Go 1.13 changes to test binary
flag handling.
* cmd/geth: make attach tests more reliable
This makes the test wait for the endpoint to come up by polling
it instead of waiting for two seconds.
* tests: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
* crypto/ecies: remove useless -dump flag in tests
* p2p/simulations: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
* build: remove workaround for ./... vendor matching
This workaround was necessary for Go 1.8. The Go 1.9 release changed
the expansion rules to exclude vendored packages.
* Makefile: use relative path for GOBIN
This makes the "Run ./build/bin/..." line look nicer.
* les: fix test binary flags for Go 1.13
Calling flag.Parse during package initialization is prohibited
as of Go 1.13 and causes test failures. Call it in TestMain instead.
This PR adds a new fork which disables EIP-1283. Internally it's called Petersburg,
but the genesis/config field is ConstantinopleFix.
The block numbers are:
7280000 for Constantinople on Mainnet
7280000 for ConstantinopleFix on Mainnet
4939394 for ConstantinopleFix on Ropsten
9999999 for ConstantinopleFix on Rinkeby (real number decided later)
This PR also defaults to using the same ConstantinopleFix number as whatever
Constantinople is set to. That is, it will default to mainnet behaviour if ConstantinopleFix
is not set.This means that for private networks which have already transitioned
to Constantinople, this PR will break the network unless ConstantinopleFix is
explicitly set!
This commit does a few things at once:
- Updates the tests to contain the latest data from ethereum/tests repo.
- Enables Constantinople state tests. This is needed to be able to
fuzz-test the evm with constantinople rules.
- Fixes the error in opSAR that we've known about for some time. I was
kind of saving it to see if we hit upon it with the random test
generator, but it's difficult to both enable the tests and have the
bug there -- we don't want to forget about it, so maybe it's better
to just fix it.
The 'from' and 'to' methods on StateTransitions are reader methods and
shouldn't have inadvertent side effects on state.
It is safe to remove the check in 'from' because account existence is
implicitly checked by the nonce and balance checks. If the account has
non-zero balance or nonce, it must exist. Even if the sender account has
nonce zero at the start of the state transition or no balance, the nonce
is incremented before execution and the account will be created at that
time.
It is safe to remove the check in 'to' because the EVM creates the
account if necessary.
Fixes#15119
* core/types, core/vm, eth, tests: regenerate gencodec files
* Makefile: update devtools target
Install protoc-gen-go and print reminders about npm, solc and protoc.
Also switch to github.com/kevinburke/go-bindata because it's more
maintained.
* contracts/ens: update contracts and regenerate with solidity v0.4.19
The newer upstream version of the FIFSRegistrar contract doesn't set the
resolver anymore. The resolver is now deployed separately.
* contracts/release: regenerate with solidity v0.4.19
* contracts/chequebook: fix fallback and regenerate with solidity v0.4.19
The contract didn't have a fallback function, payments would be rejected
when compiled with newer solidity. References to 'mortal' and 'owned'
use the local file system so we can compile without network access.
* p2p/discv5: regenerate with recent stringer
* cmd/faucet: regenerate
* dashboard: regenerate
* eth/tracers: regenerate
* internal/jsre/deps: regenerate
* dashboard: avoid sed -i because it's not portable
* accounts/usbwallet/internal/trezor: fix go generate warnings
* params: Updated finalized gascosts for ECMUL/MODEXP
* core,tests: Updates pending new tests
* tests: Updated with new tests
* core: revert state transition bugfix
* tests: Add expected failures due to #15119
* cmd/evm: adds ability to run individual state test file
* cmd/evm: Fix statetest runner to be more json friendly
* cmd/evm, tests: minor polishes, dump state on fail
Blockchain tests now include the "network" which determines the chain
config to use. Remove config matching based on test name and share the
name-to-config index with state tests.
Byzantium/Constantinople tests are still skipped because most of them
fail anyway.
Tests are now included as a submodule. This should make updating easier
and removes ~60MB of JSON data from the working copy.
State tests are replaced by General State Tests, which run the same test
with multiple fork configurations.
With the new test runner, consensus tests are run as subtests by walking
json files. Many hex issues have been fixed upstream since the last
update and most custom parsing code is replaced by existing JSON hex
types. Tests can now be marked as 'expected failures', ensuring that
fixes for those tests will trigger an update to test configuration. The
new test runner also supports parallel execution and the -short flag.
With this commit, core/state's access to the underlying key/value database is
mediated through an interface. Database errors are tracked in StateDB and
returned by CommitTo or the new Error method.
Motivation for this change: We can remove the light client's duplicated copy of
core/state. The light client now supports node iteration, so tracing and storage
enumeration can work with the light client (not implemented in this commit).
This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.
* common/math: optimize PaddedBigBytes, use it more
name old time/op new time/op delta
PaddedBigBytes-8 71.1ns ± 5% 46.1ns ± 1% -35.15% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
PaddedBigBytes-8 48.0B ± 0% 32.0B ± 0% -33.33% (p=0.000 n=20+20)
* all: unify big.Int zero checks
Various checks were in use. This commit replaces them all with Int.Sign,
which is cheaper and less code.
eg templates:
func before(x *big.Int) bool { return x.BitLen() == 0 }
func after(x *big.Int) bool { return x.Sign() == 0 }
func before(x *big.Int) bool { return x.BitLen() > 0 }
func after(x *big.Int) bool { return x.Sign() != 0 }
func before(x *big.Int) int { return x.Cmp(common.Big0) }
func after(x *big.Int) int { return x.Sign() }
* common/math, crypto/secp256k1: make ReadBits public in package math
* common: remove CurrencyToString
Move denomination values to params instead.
* common: delete dead code
* common: move big integer operations to common/math
This commit consolidates all big integer operations into common/math and
adds tests and documentation.
There should be no change in semantics for BigPow, BigMin, BigMax, S256,
U256, Exp and their behaviour is now locked in by tests.
The BigD, BytesToBig and Bytes2Big functions don't provide additional
value, all uses are replaced by new(big.Int).SetBytes().
BigToBytes is now called PaddedBigBytes, its minimum output size
parameter is now specified as the number of bytes instead of bits. The
single use of this function is in the EVM's MSTORE instruction.
Big and String2Big are replaced by ParseBig, which is slightly stricter.
It previously accepted leading zeros for hexadecimal inputs but treated
decimal inputs as octal if a leading zero digit was present.
ParseUint64 is used in places where String2Big was used to decode a
uint64.
The new functions MustParseBig and MustParseUint64 are now used in many
places where parsing errors were previously ignored.
* common: delete unused big integer variables
* accounts/abi: replace uses of BytesToBig with use of encoding/binary
* common: remove BytesToBig
* common: remove Bytes2Big
* common: remove BigTrue
* cmd/utils: add BigFlag and use it for error-checked integer flags
While here, remove environment variable processing for DirectoryFlag
because we don't use it.
* core: add missing error checks in genesis block parser
* common: remove String2Big
* cmd/evm: use utils.BigFlag
* common/math: check for 256 bit overflow in ParseBig
This is supposed to prevent silent overflow/truncation of values in the
genesis block JSON. Without this check, a genesis block that set a
balance larger than 256 bits would lead to weird behaviour in the VM.
* cmd/utils: fixup import
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.
In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.
* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test
This significantly reduces the dependency closure of ethclient, which no
longer depends on core/vm as of this change.
All uses of vm.Logs are replaced by []*types.Log. NewLog is gone too,
the constructor simply returned a literal.
The run loop, which previously contained custom opcode executes have been
removed and has been simplified to a few checks.
Each operation consists of 4 elements: execution function, gas cost function,
stack validation function and memory size function. The execution function
implements the operation's runtime behaviour, the gas cost function implements
the operation gas costs function and greatly depends on the memory and stack,
the stack validation function validates the stack and makes sure that enough
items can be popped off and pushed on and the memory size function calculates
the memory required for the operation and returns it.
This commit also allows the EVM to go unmetered. This is helpful for offline
operations such as contract calls.
Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.
The new environment is suitable to be used en the json tests, core
consensus and light client.
This commit implements EIP158 part 1, 2, 3 & 4
1. If an account is empty it's no longer written to the trie. An empty
account is defined as (balance=0, nonce=0, storage=0, code=0).
2. Delete an empty account if it's touched
3. An empty account is redefined as either non-existent or empty.
4. Zero value calls and zero value suicides no longer consume the 25k
reation costs.
params: moved core/config to params
Signed-off-by: Jeffrey Wilcke <jeffrey@ethereum.org>
This implements 1b & 1c of EIP150 by adding a new GasTable which must be
returned from the RuleSet config method. This table is used to determine
the gas prices for the current epoch.
Please note that when the CreateBySuicide gas price is set it is assumed
that we're in the new epoch phase.
In addition this PR will serve as temporary basis while refactorisation
in being done in the EVM64 PR, which will substentially overhaul the gas
price code.
Two new tests are skipped because they're buggy. Making some newer
random state tests work required implementing the 'compressed return
value encoding'.
This commit replaces the deep-copy based state revert mechanism with a
linear complexity journal. This commit also hides several internal
StateDB methods to limit the number of ways in which calling code can
use the journal incorrectly.
As usual consultation and bug fixes to the initial implementation were
provided by @karalabe, @obscuren and @Arachnid. Thank you!
This CL makes several refactors:
- Define a Tracer interface, implementing the `CaptureState` method
- Add the VM environment as the first argument of
`Tracer.CaptureState`
- Rename existing functionality `StructLogger` an make it an
implementation of `Tracer`
- Delete `StructLogCollector` and make `StructLogger` collect the logs
directly
- Change all callers to use the new `StructLogger` where necessary and
extract logs from that.
- Deletes the apparently obsolete and likely nonfunctional 'TraceCall'
from the eth API.
Callers that only wish accumulated logs can use the `StructLogger`
implementation straightforwardly. Callers that wish to efficiently
capture VM traces and operate on them without excessive copying can now
implement the `Tracer` interface to receive VM state at each step and
do with it as they wish.
This CL also removes the accumulation of logs from the vm.Environment;
this was necessary as part of the refactor, but also simplifies it by
removing a responsibility that doesn't directly belong to the
Environment.
This implements a generic approach to enabling soft forks by allowing
anyone to put in hashes of contracts that should not be interacted from.
This will help "The DAO" in their endevour to stop any whithdrawals from
any DAO contract by convincing the mining community to accept their code
hash.
We used to have reporting of bad blocks, but it was disabled
before the Frontier release. We need it back because users
are usually unable to provide the full RLP data of a bad
block when it occurs.
A shortcoming of this particular implementation is that the
origin peer is not tracked for blocks received during eth/63
sync. No origin peer info is still better than no report at
all though.
Added chain configuration options and write out during genesis database
insertion. If no "config" was found, nothing is written to the database.
Configurations are written on a per genesis base. This means
that any chain (which is identified by it's genesis hash) can have their
own chain settings.
The EVM was previously initialised and created for every CALL, CALLCODE,
DELEGATECALL and CREATE. This PR changes this behaviour so that the same
EVM can be used through the session and beyond as long as the
Environment sticks around.
Assuming the following scenario where a miner has 15% of all hashing
power and the ability to exert a moderate control over the network to
the point where if the attacker sees a message A, it can't stop A from
propagating, but what it **can** do is send a message B and ensure that
most nodes see B before A. The attacker can then selfish mine and
augment selfish mining strategy by giving his own blocks an advantage.
This change makes the time at which a block is received less relevant
and so the level of control an attacker has over the network no longer
makes a difference.
This change changes the current td algorithm `B_td > C_td` to the new
algorithm `B_td > C_td || B_td == C_td && rnd < 0.5`.
* Removed some strange code that didn't apply state reverting properly
* Refactored code setting from vm & state transition to the executioner
* Updated tests
* change gas cost for contract creating txs
* invalidate signature with s value greater than secp256k1 N / 2
* OOG contract creation if not enough gas to store code
* new difficulty adjustment algorithm
* new DELEGATECALL op code
The amount of gas available for tx execution was tracked in the
StateObject representing the coinbase account. This commit makes the gas
counter a separate type in package core, which avoids unintended
consequences of intertwining the counter with state logic.
* Moved `vm.Transfer` to `core` package and changed execution to call
`env.Transfer` instead of `core.Transfer` directly.
* core/vm: byte code VM moved to jump table instead of switch
* Moved `vm.Transfer` to `core` package and changed execution to call
`env.Transfer` instead of `core.Transfer` directly.
* Byte code VM now shares the same code as the JITVM
* Renamed Context to Contract
* Changed initialiser of state transition & unexported methods
* Removed the Execution object and refactor `Call`, `CallCode` &
`Create` in to their own functions instead of being methods.
* Removed the hard dep on the state for the VM. The VM now
depends on a Database interface returned by the environment. In the
process the core now depends less on the statedb by usage of the env
* Moved `Log` from package `core/state` to package `core/vm`.
