Prior to this change, eth_call changed the balance of the sender account in the
EVM environment to 2^256 wei to cover the gas cost of the call execution.
We've had this behavior for a long time even though it's super confusing.
This commit sets the default call gasprice to zero instead of updating the balance,
which is better because it makes eth_call semantics less surprising. Removing
the built-in balance assignment also makes balance overrides work as expected.
This makes eth_call and eth_estimateGas use the zero address
as sender when the "from" parameter is not supplied.
Co-authored-by: Felix Lange <fjl@twurst.com>
This replaces the JavaScript interpreter used by the console with goja,
which is actively maintained and a lot faster than otto. Clef still uses otto
and eth/tracers still uses duktape, so we are currently dependent on three
different JS interpreters. We're looking to replace the remaining uses of otto
soon though.
* log: delete RotatingFileHandler
We added this for the dashboard, which is gone now. The
handler never really worked well and had data race and file
handling issues.
* internal/debug: remove unused RotatingFileHandler setup code
* build: remove env.sh
This removes the dirty symlink-to-self hack we've had for years. The
script was added to enable building without GOPATH and did that job
reliably for all this time. We can remove the workaround because modern
Go supports building without GOPATH natively.
* Makefile: add GO111MODULE=on to environment
* internal/testlog: print file+line number of log call in test log
This changes the unit test logger to print the actual file and line
number of the logging call instead of "testlog.go:44".
Output of 'go test -v -run TestServerListen ./p2p' before this change:
=== RUN TestServerListen
--- PASS: TestServerListen (0.00s)
testlog.go:44: DEBUG[01-08|15:16:31.651] UDP listener up addr=127.0.0.1:62678
testlog.go:44: DEBUG[01-08|15:16:31.651] TCP listener up addr=127.0.0.1:62678
testlog.go:44: TRACE[01-08|15:16:31.652] Accepted connection addr=127.0.0.1:62679
And after:
=== RUN TestServerListen
--- PASS: TestServerListen (0.00s)
server.go:868: DEBUG[01-08|15:25:35.679] TCP listener up addr=127.0.0.1:62712
server.go:557: DEBUG[01-08|15:25:35.679] UDP listener up addr=127.0.0.1:62712
server.go:912: TRACE[01-08|15:25:35.680] Accepted connection addr=127.0.0.1:62713
* internal/testlog: document use of t.Helper
* build: use golangci-lint
This changes build/ci.go to download and run golangci-lint instead
of gometalinter.
* core/state: fix unnecessary conversion
* p2p/simulations: fix lock copying (found by go vet)
* signer/core: fix unnecessary conversions
* crypto/ecies: remove unused function cmpPublic
* core/rawdb: remove unused function print
* core/state: remove unused function xTestFuzzCutter
* core/vm: disable TestWriteExpectedValues in a different way
* core/forkid: remove unused function checksum
* les: remove unused type proofsData
* cmd/utils: remove unused functions prefixedNames, prefixFor
* crypto/bn256: run goimports
* p2p/nat: fix goimports lint issue
* cmd/clef: avoid using unkeyed struct fields
* les: cancel context in testRequest
* rlp: delete unreachable code
* core: gofmt
* internal/build: simplify DownloadFile for Go 1.11 compatibility
* build: remove go test --short flag
* .travis.yml: disable build cache
* whisper/whisperv6: fix ineffectual assignment in TestWhisperIdentityManagement
* .golangci.yml: enable goconst and ineffassign linters
* build: print message when there are no lint issues
* internal/build: refactor download a bit
* build: bump PPAs to Go 1.13 (via longsleep), keep Trusty on 1.11
* travis, build, vendor: use own Go bundle for PPA builds
* travis, build, internal, vendor: smarter Go bundler, own untar
* build: updated ci-notes with new Go bundling, only make, don't test
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.
* graphql, internal/ethapi: extend eth_call
This PR offers the third option parameter for eth_call API.
Caller can specify a batch of contracts for overriding the
original account metadata(nonce, balance, code, state).
It has a few advantages:
* It's friendly for debugging
* It's can make on-chain contract lighter for getting rid of
state access functions
* core, internal: address comments
* accounts/mananger, internal/ethapi/api: Add new function AllAccounts on account manager to remove the duplication code on getting all wallets accounts
* Rename to Accounts
* Rename to AllAccounts
This change ensures 'blockHash', 'blockNumber' and 'transactionIndex'
are set to null for pending transactions. This behavior is required by
the Ethereum JSON-RPC spec.
* add-date-to unstable
* fields-insteadof-split
* internal/build: support building with missing git
* docker: add git history back to support commit date in version
* internal/build: use PR commits hashes for PR builds
* accounts: add note about backing up the keystore
* cmd, accounts: move the printout to accountCreate
* internal, signer: add info when new account is created via rpc
* cmd, internal, signer: split logs
* cmd/geth: make account new output a bit more verbose
* accounts, core, internal, node: Add support for smartcard wallets
* accounts, internal: Changes in response to review
* vendor: pull in missing go-echd library
* accounts/scwallet, console: user friendly card opening
* accounts/scwallet: ordered wallets, tighter events, derivation logs
* accounts, console: frendly card errors, support pin unblock
* accounts/scwallet: fix crypto API change
* accounts/scwallet: rebase and update
* Fix some linter issues
* Remove the direct dependency on libpcsclite
Instead, use a go library that communicates with pcscd over a socket.
Also update the changes introduced by @gravityblast since this PR's
inception
* Temporary fix to the ADBU status call
* fix wallet status update
This is a temporary fix, better checks need to
be performed once the whole process has been
validated.
* Fix key derivation
* Add some documentation
* Update a comment to reflect the workings of the updated system
* Vendor keycard-go/derivationpath
* Formatting fixes
* Add instructions on how to install the card
* Achieve full transaction signature+sending
* PK derivation has to be supported by the card
* Fix linter issues
* Upgrade to keycard app v2.1.1
* Set gballet as codeowner of the smartcard wallet dir
* fix unnecessary condition linter warning
* refuse to overwrite the master key of a previously initialized card
* refresh the account list when initializing the card
* Update the card preparation instructions based on review feedback
* 'sanitize' JSON input
Co-Authored-By: gballet <gballet@gmail.com>
* Apply suggestions from code review
Co-Authored-By: gballet <gballet@gmail.com>
* fix a serialization error
* more review feedback
* More review feedback
* Can now specify the number of empty accounts to derive
* Fix rebase error: include norm package
* Update bip-39 ref and remove ebfe/scard from vendor
* Add missing dependency
* signer/clef: make use of json-rpc notification
* signer: tidy up output of OnApprovedTx
* accounts/external, signer: implement remote signing of text, make accounts_sign take hexdata
* clef: added basic testscript
* signer, external, api: add clique signing test to debug rpc, fix clique signing in clef
* signer: fix clique interoperability between geth and clef
* clef: rename networkid switch to chainid
* clef: enable chainid flag
* clef, signer: minor changes from review
* clef: more tests for signer
* Initial work on a graphql API
* Added receipts, and more transaction fields.
* Finish receipts, add logs
* Add transactionCount to block
* Add types and .
* Update Block type to be compatible with ethql
* Rename nonce to transactionCount in Account, to be compatible with ethql
* Update transaction, receipt and log to match ethql
* Add query operator, for a range of blocks
* Added ommerCount to Block
* Add transactionAt and ommerAt to Block
* Added sendRawTransaction mutation
* Add Call and EstimateGas to graphQL API
* Refactored to use hexutil.Bytes instead of HexBytes
* Replace BigNum with hexutil.Big
* Refactor call and estimateGas to use ethapi struct type
* Replace ethgraphql.Address with common.Address
* Replace ethgraphql.Hash with common.Hash
* Converted most quantities to Long instead of Int
* Add support for logs
* Fix bug in runFilter
* Restructured Transaction to work primarily with headers, so uncle data is reported properly
* Add gasPrice API
* Add protocolVersion API
* Add syncing API
* Moved schema into its own source file
* Move some single use args types into anonymous structs
* Add doc-comments
* Fixed backend fetching to use context
* Added (very) basic tests
* Add documentation to the graphql schema
* Fix reversion for formatting of big numbers
* Correct spelling error
* s/BigInt/Long/
* Update common/types.go
* Fixes in response to review
* Fix lint error
* Updated calls on private functions
* Fix typo in graphql.go
* Rollback ethapi breaking changes for graphql support
Co-Authored-By: Arachnid <arachnid@notdot.net>
Until this commit, when sending an RPC request that called `NewEVM`, a blank `vm.Config`
would be taken so as to set some options, based on the default configuration. If some extra
configuration switches were passed to the blockchain, those would be ignored.
This PR adds a function to get the config from the blockchain, and this is what is now used
for RPC calls.
Some subsequent changes need to be made, see https://github.com/ethereum/go-ethereum/pull/17955#pullrequestreview-182237244
for the details of the discussion.
* first impl of eth_getProof
* fixed docu
* added comments and refactored based on comments from holiman
* created structs
* handle errors correctly
* change Value to *hexutil.Big in order to have the same output as parity
* use ProofList as return type
* consensus/ethash: start remote ggoroutine to handle remote mining
* consensus/ethash: expose remote miner api
* consensus/ethash: expose submitHashrate api
* miner, ethash: push empty block to sealer without waiting execution
* consensus, internal: add getHashrate API for ethash
* consensus: add three method for consensus interface
* miner: expose consensus engine running status to miner
* eth, miner: specify etherbase when miner created
* miner: commit new work when consensus engine is started
* consensus, miner: fix some logics
* all: delete useless interfaces
* consensus: polish a bit
* build: add support for different package and binary names
* build: bump up copyright date
* build: change default PackageName to empty string
* build, internal, swarm: enhance build/release process
* build: hack ethereum-swarm as a "depends" in deb package
* build/ci: remove redundant variables
* build, cmd, mobile, params, swarm: remove VERSION file; rename Version to VersionMeta;
* internal: remove VERSION() method which reads VERSION file
* build: fix VersionFilePath to Version
* Makefile: remove clean_go_build_cache.sh until it works
* Makefile: revert removal of clean_go_build_cache.sh
These RPC calls are analogous to Parity's parity_addReservedPeer and
parity_removeReservedPeer.
They are useful for adjusting the trusted peer set during runtime,
without requiring restarting the server.
* debug: Use pprof goroutine writer in debug.Stacks() to ensure all goroutines are captured.
* Up to 64MB limit, previous code only captured first 1MB of goroutines.
* internal/debug: simplify stacks handler
* fix typo
* fix pointer receiver
ToECDSAPub was unsafe because it returned a non-nil key with nil X, Y in
case of invalid input. This change replaces ToECDSAPub with
UnmarshalPubkey across the codebase.
Most of these methods did not contain all the relevant information
inside the object and were not using a similar formatting type.
Moreover, the existence of a suboptimal String method breaks usage
with more advanced data dumping tools like go-spew.
This commit:
- Adds a --msgfile option to read the message to sign from a file
instead of command line argument.
- Adds a unit test for signing subcommands.
- Removes some weird whitespace in the code.
* 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
* eth, internal: Implement using trie diffs
* eth, internal: Changes in response to review
* eth: More fixes to getModifiedAccountsBy*
* eth: minor polishes on error capitalization
* .dockerignore, internal/build: Read git information directly from file
This commit changes the way of retrieving git commit and branch for build
environment from running git command to reading git files directly.
This commit also adds required git files into Docker build context.
fixes: #15346
* .dockerignore: workaround for including some files in .git
* core: remove redundant storage of transactions and receipts
* core, eth, internal: new transaction schema usage polishes
* eth: implement upgrade mechanism for db deduplication
* core, eth: drop old sequential key db upgrader
* eth: close last iterator on successful db upgrage
* core: prefix the lookup entries to make their purpose clearer
As stated in the documentation, this method should be called traceBlockFromFile
and not traceBlockByFile. Previously this would result in a 'The method ... does
not exist/is not available' error.
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).
More context in the bug This solves the problems of transactions being
submitted simultaneously, and getting the same nonce, due to the gap (due to
signing) between nonce-issuance and nonce-update. With this PR, a lock will
need to be acquired whenever a nonce is used, and released when the transaction
is submitted or errors out.
This commit is a preparation for the upcoming metropolis hardfork. It
prepares the state, core and vm packages such that integration with
metropolis becomes less of a hassle.
* Difficulty calculation requires header instead of individual
parameters
* statedb.StartRecord renamed to statedb.Prepare and added Finalise
method required by metropolis, which removes unwanted accounts from
the state (i.e. selfdestruct)
* State keeps record of destructed objects (in addition to dirty
objects)
* core/vm pre-compiles may now return errors
* core/vm pre-compiles gas check now take the full byte slice as argument
instead of just the size
* core/vm now keeps several hard-fork instruction tables instead of a
single instruction table and removes the need for hard-fork checks in
the instructions
* core/vm contains a empty restruction function which is added in
preparation of metropolis write-only mode operations
* Adds the bn256 curve
* Adds and sets the metropolis chain config block parameters (2^64-1)
Currently http cors and websocket origins are a comma separated string in the
config object. These are replaced with string arrays that are more expressive in
case of a config file.
This commit adds a build step to travis to auto-delete unstable archives older than
14 days (our regular release schedule) from Azure via ci.go purge.
The commit also pulls in the latest Azure storage code, also switching over from
the old import path (github.com/Azure/azure-sdk-for-go) to the new split one
(github.com/Azure/azure-storage-go).
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.
* swarm/api: fix build/tests on unsupported platforms
Skip FUSE tests if FUSE is unavailable and change build constraints so
the 'lesser' platforms aren't mentioned explicitly. The test are
compiled on all platforms to prevent regressions in _fallback.go
Also gofmt -w -s because why not.
* internal/web3ext: fix swarmfs wrappers
Remove inputFormatter specifications so users get an error
when passing the wrong number of arguments.
* swarm/api: improve FUSE-related logging and APIs
The API now returns JSON objects instead of strings.
Log messages for invalid arguments are removed.
There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.
This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.
* 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
* core,eth,internal: Added `debug_getBadBlocks()` method
When bad blocks are discovered, these are stored within geth.
An RPC-endpoint makes them availablewithin the `debug`
namespace. This feature makes it easier to discover network forks.
```
* core, api: go format + docs
* core/blockchain: Documentation, fix minor nitpick
* core: fix failing blockchain 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
Gas estimation currently mostly works, but can underestimate for more funky
refunds. This is because various ops (e.g. CALL) need more gas to run than they
actually consume (e.g. 2300 stipend that is refunded if not used). With more
intricate contract interplays, it becomes almost impossible to return a proper
value to the user.
This commit swaps out the simplistic gas estimation to a binary search approach,
honing in on the correct gas use. This does mean that gas estimation needs to
rerun the transaction log(max-price) times to measure whether it fails or not,
but it's a price paid by the transaction issuer, and it should be worth it to
support proper estimates.
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.
To address increasing complexity in code that handles signatures, this PR
discards all notion of "different" signature types at the library level. Both
the crypto and accounts package is reduced to only be able to produce plain
canonical secp256k1 signatures. This makes the crpyto APIs much cleaner,
simpler and harder to abuse.
The transaction pool keeps track of the current nonce in its local pendingState. When a
new block comes in the pendingState is reset. During the reset it fetches multiple times
the current state through the use of the currentState callback. When a second block comes
in during the reset its possible that the state changes during the reset. If that block
holds transactions that are currently in the pool the local pendingState that is used to
determine nonces can get out of sync.
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.
* cmd/bzzd: add missing p2p/discovery flags
* cmd/bzzd: fix two bugs crashing bzzd if bootnodes flag given
* cmd/bzzd: make no swap default, renamed flag bzznoswap->bzzswap
* internal/web3ext: correct methods for bzz IPC module
* cmd/bzzd: ethapi param not mandatory. Warning if no blockchain
* cmd/bzzd: correct default IPC modules in help string
* cmd/utils: fix help description for networkId - add Ropsten
* cmd/bzz, swarm/api, swarm/network: add swarm networkId flag
* cmd/bzzd: change nosync flag to sync and BootTFlag
I didn't add this initially because the command I tried was too slow.
The 'git for-each-ref ...' invocation takes 40ms on my machine. That
ought to be acceptable.
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 commit includes several API changes:
- The behavior of eth_sign is changed. It now accepts an arbitrary
message, prepends the well-known string
\x19Ethereum Signed Message:\n<length of message>
hashes the result using keccak256 and calculates the signature of
the hash. This breaks backwards compatability!
- personal_sign(hash, address [, password]) is added. It has the same
semantics as eth_sign but also accepts a password. The private key
used to sign the hash is temporarily unlocked in the scope of the
request.
- personal_recover(message, signature) is added and returns the
address for the account that created a signature.
This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.
You can update dependencies via trash --update.
All dependencies have been updated to their latest version.
Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.
The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.
golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.
