build: use golangci-lint (#20295)

* 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

core/blockchain.go

@@ -42,7 +42,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
-	"github.com/hashicorp/golang-lru"
+	lru "github.com/hashicorp/golang-lru"
 )
 
 var (

core/forkid/forkid.go

@@ -186,13 +186,6 @@ func newFilter(config *params.ChainConfig, genesis common.Hash, headfn func() ui
 	}
 }
 
-// checksum calculates the IEEE CRC32 checksum of a block number.
-func checksum(fork uint64) uint32 {
-	var blob [8]byte
-	binary.BigEndian.PutUint64(blob[:], fork)
-	return crc32.ChecksumIEEE(blob[:])
-}
-
 // checksumUpdate calculates the next IEEE CRC32 checksum based on the previous
 // one and a fork block number (equivalent to CRC32(original-blob || fork)).
 func checksumUpdate(hash uint32, fork uint64) uint32 {

core/rawdb/freezer_table_test.go

@@ -41,14 +41,6 @@ func getChunk(size int, b int) []byte {
 	return data
 }
 
-func print(t *testing.T, f *freezerTable, item uint64) {
-	a, err := f.Retrieve(item)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("db[%d] =  %x\n", item, a)
-}
-
 // TestFreezerBasics test initializing a freezertable from scratch, writing to the table,
 // and reading it back.
 func TestFreezerBasics(t *testing.T) {

core/state/state_object_test.go

@@ -18,10 +18,7 @@ package state
 
 import (
 	"bytes"
-	"fmt"
-	"math/rand"
 	"testing"
-	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 )
@@ -35,9 +32,7 @@ func BenchmarkCutOriginal(b *testing.B) {
 
 func BenchmarkCutsetterFn(b *testing.B) {
 	value := common.HexToHash("0x01")
-	cutSetFn := func(r rune) bool {
-		return int32(r) == int32(0)
-	}
+	cutSetFn := func(r rune) bool { return r == 0 }
 	for i := 0; i < b.N; i++ {
 		bytes.TrimLeftFunc(value[:], cutSetFn)
 	}
@@ -49,22 +44,3 @@ func BenchmarkCutCustomTrim(b *testing.B) {
 		common.TrimLeftZeroes(value[:])
 	}
 }
-
-func xTestFuzzCutter(t *testing.T) {
-	rand.Seed(time.Now().Unix())
-	for {
-		v := make([]byte, 20)
-		zeroes := rand.Intn(21)
-		rand.Read(v[zeroes:])
-		exp := bytes.TrimLeft(v[:], "\x00")
-		got := common.TrimLeftZeroes(v)
-		if !bytes.Equal(exp, got) {
-
-			fmt.Printf("Input %x\n", v)
-			fmt.Printf("Exp %x\n", exp)
-			fmt.Printf("Got %x\n", got)
-			t.Fatalf("Error")
-		}
-		//break
-	}
-}

core/vm/instructions_test.go

@@ -232,7 +232,9 @@ func getResult(args []*twoOperandParams, opFn executionFunc) []TwoOperandTestcas
 
 // utility function to fill the json-file with testcases
 // Enable this test to generate the 'testcases_xx.json' files
-func xTestWriteExpectedValues(t *testing.T) {
+func TestWriteExpectedValues(t *testing.T) {
+	t.Skip("Enable this test to create json test cases.")
+
 	for name, method := range twoOpMethods {
 		data, err := json.Marshal(getResult(commonParams, method))
 		if err != nil {
@@ -243,7 +245,6 @@ func xTestWriteExpectedValues(t *testing.T) {
 			t.Fatal(err)
 		}
 	}
-	t.Fatal("This test should not be activated")
 }
 
 // TestJsonTestcases runs through all the testcases defined as json-files