build: enable deadcode linter

* also fixes warnings generated by linter
 * fixes #15473

accounts/abi/numbers.go

@@ -50,6 +50,7 @@ func U256(n *big.Int) []byte {
 }
 
 // checks whether the given reflect value is signed. This also works for slices with a number type
+// nolint: deadcode
 func isSigned(v reflect.Value) bool {
 	switch v.Type() {
 	case int_ts, int8_ts, int16_ts, int32_ts, int64_ts, int_t, int8_t, int16_t, int32_t, int64_t:

accounts/usbwallet/ledger.go

@@ -47,6 +47,7 @@ type ledgerParam1 byte
 // specific opcodes. The same parameter values may be reused between opcodes.
 type ledgerParam2 byte
 
+// nolint: deadcode
 const (
 	ledgerOpRetrieveAddress  ledgerOpcode = 0x02 // Returns the public key and Ethereum address for a given BIP 32 path
 	ledgerOpSignTransaction  ledgerOpcode = 0x04 // Signs an Ethereum transaction after having the user validate the parameters

build/ci.go

@@ -323,7 +323,14 @@ func doLint(cmdline []string) {
 	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v1"), "--install")
 
 	// Run fast linters batched together
-	configs := []string{"--vendor", "--disable-all", "--enable=vet", "--enable=gofmt", "--enable=misspell"}
+	configs := []string{"--vendor", "-t",
+		"--disable-all",
+		"--exclude=cmd/faucet/website.go",
+		"--enable=vet",
+		"--enable=gofmt",
+		"--enable=misspell",
+		"--enable=deadcode",
+	}
 	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v1"), append(configs, packages...)...)
 
 	// Run slow linters one by one

consensus/clique/clique.go

@@ -51,6 +51,7 @@ const (
 )
 
 // Clique proof-of-authority protocol constants.
+// nolint: deadcode
 var (
 	epochLength = uint64(30000) // Default number of blocks after which to checkpoint and reset the pending votes
 	blockPeriod = uint64(15)    // Default minimum difference between two consecutive block's timestamps

consensus/ethash/algorithm.go

@@ -163,6 +163,7 @@ func swap(buffer []byte) {
 // prepare converts an ethash cache or dataset from a byte stream into the internal
 // int representation. All ethash methods work with ints to avoid constant byte to
 // int conversions as well as to handle both little and big endian systems.
+// nolint: deadcode
 func prepare(dest []uint32, src []byte) {
 	for i := 0; i < len(dest); i++ {
 		dest[i] = binary.LittleEndian.Uint32(src[i*4:])

core/asm/compiler.go

@@ -267,6 +267,7 @@ func (err compileError) Error() string {
 	return fmt.Sprintf("%d syntax error: unexpected %v, expected %v", err.lineno, err.got, err.want)
 }
 
+// nolint: deadcode
 var (
 	errExpBol            = errors.New("expected beginning of line")
 	errExpElementOrLabel = errors.New("expected beginning of line")

core/chain_makers.go

@@ -31,6 +31,7 @@ import (
 )
 
 // So we can deterministically seed different blockchains
+// nolint: deadcode
 var (
 	canonicalSeed = 1
 	forkSeed      = 2
@@ -229,6 +230,7 @@ func makeHeader(config *params.ChainConfig, parent *types.Block, state *state.St
 // newCanonical creates a chain database, and injects a deterministic canonical
 // chain. Depending on the full flag, if creates either a full block chain or a
 // header only chain.
+// nolint: deadcode
 func newCanonical(n int, full bool) (ethdb.Database, *BlockChain, error) {
 	// Initialize a fresh chain with only a genesis block
 	gspec := new(Genesis)

core/genesis.go

@@ -86,6 +86,7 @@ type GenesisAccount struct {
 }
 
 // field type overrides for gencodec
+// nolint: deadcode
 type genesisSpecMarshaling struct {
 	Nonce      math.HexOrDecimal64
 	Timestamp  math.HexOrDecimal64

core/tx_pool.go

@@ -35,6 +35,7 @@ import (
 	"gopkg.in/karalabe/cookiejar.v2/collections/prque"
 )
 
+// nolint: deadcode
 const (
 	// chainHeadChanSize is the size of channel listening to ChainHeadEvent.
 	chainHeadChanSize = 10

core/types/block.go

@@ -86,6 +86,7 @@ type Header struct {
 }
 
 // field type overrides for gencodec
+// nolint: deadcode
 type headerMarshaling struct {
 	Difficulty *hexutil.Big
 	Number     *hexutil.Big

core/types/log.go

@@ -56,6 +56,7 @@ type Log struct {
 	Removed bool `json:"removed"`
 }
 
+// nolint: deadcode
 type logMarshaling struct {
 	Data        hexutil.Bytes
 	BlockNumber hexutil.Uint64

core/types/receipt.go

@@ -57,6 +57,7 @@ type Receipt struct {
 	GasUsed         *big.Int       `json:"gasUsed" gencodec:"required"`
 }
 
+// nolint: deadcode
 type receiptMarshaling struct {
 	PostState         hexutil.Bytes
 	Status            hexutil.Uint

core/types/transaction.go

@@ -32,6 +32,7 @@ import (
 
 //go:generate gencodec -type txdata -field-override txdataMarshaling -out gen_tx_json.go
 
+// nolint: deadcode
 var (
 	ErrInvalidSig = errors.New("invalid transaction v, r, s values")
 	errNoSigner   = errors.New("missing signing methods")
@@ -71,6 +72,7 @@ type txdata struct {
 	Hash *common.Hash `json:"hash" rlp:"-"`
 }
 
+// nolint: deadcode
 type txdataMarshaling struct {
 	AccountNonce hexutil.Uint64
 	Price        *hexutil.Big

core/vm/logger.go

@@ -66,6 +66,7 @@ type StructLog struct {
 }
 
 // overrides for gencodec
+// nolint: deadcode
 type structLogMarshaling struct {
 	Stack   []*math.HexOrDecimal256
 	Gas     math.HexOrDecimal64

core/vm/memory_table.go

@@ -65,12 +65,6 @@ func memoryCall(stack *Stack) *big.Int {
 	return math.BigMax(x, y)
 }
 
-func memoryCallCode(stack *Stack) *big.Int {
-	x := calcMemSize(stack.Back(5), stack.Back(6))
-	y := calcMemSize(stack.Back(3), stack.Back(4))
-
-	return math.BigMax(x, y)
-}
 func memoryDelegateCall(stack *Stack) *big.Int {
 	x := calcMemSize(stack.Back(4), stack.Back(5))
 	y := calcMemSize(stack.Back(2), stack.Back(3))

crypto/sha3/xor.go

@@ -13,4 +13,5 @@ var (
 	copyOutUnaligned = copyOutGeneric
 )
 
+// nolint: deadcode
 const xorImplementationUnaligned = "generic"

crypto/sha3/xor_unaligned.go

@@ -55,4 +55,5 @@ var (
 	copyOut = copyOutUnaligned
 )
 
+// nolint: deadcode
 const xorImplementationUnaligned = "unaligned"

eth/config.go

@@ -115,6 +115,7 @@ type Config struct {
 	PowShared bool   `toml:"-"`
 }
 
+// nolint: deadcode
 type configMarshaling struct {
 	ExtraData hexutil.Bytes
 }

eth/downloader/downloader.go

@@ -69,6 +69,7 @@ var (
 	fsCriticalTrials       = uint32(32) // Number of times to retry in the cricical section before bailing
 )
 
+// nolint: deadcode
 var (
 	errBusy                    = errors.New("busy")
 	errUnknownPeer             = errors.New("peer is unknown or unhealthy")

les/bloombits.go

@@ -73,6 +73,7 @@ func (eth *LightEthereum) startBloomHandlers() {
 	}
 }
 
+// nolint: deadcode
 const (
 	// bloomConfirms is the number of confirmation blocks before a bloom section is
 	// considered probably final and its rotated bits are calculated.

les/serverpool.go

@@ -36,6 +36,7 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
+// nolint: deadcode
 const (
 	// After a connection has been ended or timed out, there is a waiting period
 	// before it can be selected for connection again.

les/sync.go

@@ -25,6 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/light"
 )
 
+// nolint: deadcode
 const (
 	//forceSyncCycle      = 10 * time.Second // Time interval to force syncs, even if few peers are available
 	minDesiredPeerCount = 5 // Amount of peers desired to start syncing

p2p/discover/node.go

@@ -412,6 +412,7 @@ func logdist(a, b common.Hash) int {
 }
 
 // hashAtDistance returns a random hash such that logdist(a, b) == n
+// nolint: deadcode
 func hashAtDistance(a common.Hash, n int) (b common.Hash) {
 	if n == 0 {
 		return a

p2p/discover/udp.go

@@ -47,6 +47,7 @@ var (
 )
 
 // Timeouts
+// nolint: deadcode
 const (
 	respTimeout = 500 * time.Millisecond
 	sendTimeout = 500 * time.Millisecond

p2p/discv5/net.go

@@ -34,6 +34,7 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
+// nolint: deadcode
 var (
 	errInvalidEvent = errors.New("invalid in current state")
 	errNoQuery      = errors.New("no pending query")
@@ -48,6 +49,7 @@ const (
 	lowPort               = 1024
 )
 
+// nolint: deadcode
 const testTopic = "foo"
 
 const (
@@ -825,12 +827,11 @@ type nodeEvent uint
 
 //go:generate stringer -type=nodeEvent
 
+//
 const (
-	invalidEvent nodeEvent = iota // zero is reserved
-
 	// Packet type events.
 	// These correspond to packet types in the UDP protocol.
-	pingPacket
+	pingPacket nodeEvent = iota + 1
 	pongPacket
 	findnodePacket
 	neighborsPacket

p2p/discv5/node.go

@@ -413,6 +413,7 @@ func logdist(a, b common.Hash) int {
 }
 
 // hashAtDistance returns a random hash such that logdist(a, b) == n
+// nolint: deadcode
 func hashAtDistance(a common.Hash, n int) (b common.Hash) {
 	if n == 0 {
 		return a

p2p/discv5/nodeevent_string.go

@@ -1,25 +1,26 @@
-// Code generated by "stringer -type nodeEvent"; DO NOT EDIT
+// Code generated by "stringer -type=nodeEvent"; DO NOT EDIT.
 
 package discv5
 
 import "fmt"
 
 const (
-	_nodeEvent_name_0 = "invalidEventpingPacketpongPacketfindnodePacketneighborsPacketfindnodeHashPackettopicRegisterPackettopicQueryPackettopicNodesPacket"
+	_nodeEvent_name_0 = "pingPacketpongPacketfindnodePacketneighborsPacketfindnodeHashPackettopicRegisterPackettopicQueryPackettopicNodesPacket"
 	_nodeEvent_name_1 = "pongTimeoutpingTimeoutneighboursTimeout"
 )
 
 var (
-	_nodeEvent_index_0 = [...]uint8{0, 12, 22, 32, 46, 61, 79, 98, 114, 130}
+	_nodeEvent_index_0 = [...]uint8{0, 10, 20, 34, 49, 67, 86, 102, 118}
 	_nodeEvent_index_1 = [...]uint8{0, 11, 22, 39}
 )
 
 func (i nodeEvent) String() string {
 	switch {
-	case 0 <= i && i <= 8:
+	case 1 <= i && i <= 8:
+		i -= 1
 		return _nodeEvent_name_0[_nodeEvent_index_0[i]:_nodeEvent_index_0[i+1]]
-	case 265 <= i && i <= 267:
+	case 264 <= i && i <= 266:
-		i -= 265
+		i -= 264
 		return _nodeEvent_name_1[_nodeEvent_index_1[i]:_nodeEvent_index_1[i+1]]
 	default:
 		return fmt.Sprintf("nodeEvent(%d)", i)

p2p/discv5/ntp.go

@@ -44,6 +44,7 @@ func (s durationSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 
 // checkClockDrift queries an NTP server for clock drifts and warns the user if
 // one large enough is detected.
+// nolint: deadcode
 func checkClockDrift() {
 	drift, err := sntpDrift(ntpChecks)
 	if err != nil {

p2p/discv5/table.go

@@ -32,6 +32,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 )
 
+// nolint: deadcode
 const (
 	alpha      = 3  // Kademlia concurrency factor
 	bucketSize = 16 // Kademlia bucket size

p2p/discv5/udp.go

@@ -35,6 +35,7 @@ import (
 const Version = 4
 
 // Errors
+// nolint: deadcode
 var (
 	errPacketTooSmall   = errors.New("too small")
 	errBadHash          = errors.New("bad hash")
@@ -47,6 +48,7 @@ var (
 )
 
 // Timeouts
+// nolint: deadcode
 const (
 	respTimeout = 500 * time.Millisecond
 	sendTimeout = 500 * time.Millisecond

p2p/message.go

@@ -114,6 +114,7 @@ func SendItems(w MsgWriter, msgcode uint64, elems ...interface{}) error {
 
 // netWrapper wraps a MsgReadWriter with locks around
 // ReadMsg/WriteMsg and applies read/write deadlines.
+// nolint: deadcode
 type netWrapper struct {
 	rmu, wmu sync.Mutex
 

p2p/peer.go

@@ -41,6 +41,7 @@ const (
 	pingInterval = 15 * time.Second
 )
 
+// nolint: deadcode
 const (
 	// devp2p message codes
 	handshakeMsg = 0x00

p2p/server.go

@@ -35,6 +35,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 )
 
+// nolint: deadcode
 const (
 	defaultDialTimeout      = 15 * time.Second
 	refreshPeersInterval    = 30 * time.Second

swarm/network/kademlia/kademlia.go

@@ -307,6 +307,7 @@ type nodesByDistance struct {
 	target Address
 }
 
+// nolint: deadcode
 func sortedByDistanceTo(target Address, slice []Node) bool {
 	var last Address
 	for i, node := range slice {

swarm/storage/dbstore.go

@@ -38,6 +38,7 @@ import (
 	"github.com/syndtr/goleveldb/leveldb/iterator"
 )
 
+// nolint: deadcode
 const (
 	defaultDbCapacity = 5000000
 	defaultRadius     = 0 // not yet used

swarm/storage/netstore.go

@@ -77,6 +77,7 @@ func NewNetStore(hash SwarmHasher, lstore *LocalStore, cloud CloudStore, params
 	}
 }
 
+// nolint: deadcode
 const (
 	// maximum number of peers that a retrieved message is delivered to
 	requesterCount = 3

whisper/whisperv2/topic.go

@@ -104,6 +104,7 @@ func newTopicMatcher(topics ...[]Topic) *topicMatcher {
 }
 
 // newTopicMatcherFromBinary create a topic matcher from a list of binary conditions.
+// nolint: deadcode
 func newTopicMatcherFromBinary(data ...[][]byte) *topicMatcher {
 	topics := make([][]Topic, len(data))
 	for i, condition := range data {
@@ -114,6 +115,7 @@ func newTopicMatcherFromBinary(data ...[][]byte) *topicMatcher {
 
 // newTopicMatcherFromStrings creates a topic matcher from a list of textual
 // conditions.
+// nolint: deadcode
 func newTopicMatcherFromStrings(data ...[]string) *topicMatcher {
 	topics := make([][]Topic, len(data))
 	for i, condition := range data {