*: Fixed some linter check errors (pingcap#25608)

executor/analyze_test.go

@@ -606,6 +606,7 @@ func (s *testSuite1) TestAnalyzeIncrementalStreaming(c *C) {
 	s.testAnalyzeIncremental(tk, c)
 }
 
+// nolint:unused
 func (s *testSuite1) testAnalyzeIncremental(tk *testkit.TestKit, c *C) {
 	tk.MustExec("use test")
 	tk.MustExec("drop table if exists t")

executor/distsql_test.go

@@ -36,6 +36,7 @@ import (
 	"github.com/pingcap/tidb/util/testkit"
 )
 
+// nolint:unused
 func checkGoroutineExists(keyword string) bool {
 	buf := new(bytes.Buffer)
 	profile := pprof.Lookup("goroutine")

executor/memory_test.go

@@ -104,12 +104,14 @@ func (s *testMemoryLeak) TestPBMemoryLeak(c *C) {
 	c.Assert(s.memDiff(inUseFinal, inUseAfter), Less, delta)
 }
 
+// nolint:unused
 func (s *testMemoryLeak) readMem() (allocated, heapInUse uint64) {
 	var stat runtime.MemStats
 	runtime.ReadMemStats(&stat)
 	return stat.TotalAlloc, stat.HeapInuse
 }
 
+// nolint:unused
 func (s *testMemoryLeak) memDiff(m1, m2 uint64) uint64 {
 	if m1 > m2 {
 		return m1 - m2

planner/core/prepare_test.go

@@ -345,6 +345,7 @@ func (s *testPrepareSerialSuite) TestPrepareTableAsNameOnGroupByWithCache(c *C)
 	tk.MustQuery("execute stmt").Sort().Check(testkit.Rows("partner1", "partner2", "partner3", "partner4"))
 }
 
+// nolint:unused
 func readGaugeInt(g prometheus.Gauge) int {
 	ch := make(chan prometheus.Metric, 1)
 	g.Collect(ch)

statistics/handle/handle_test.go

@@ -847,6 +847,7 @@ func (s *testStatsSuite) TestBuildGlobalLevelStats(c *C) {
 	c.Assert(len(result.Rows()), Equals, 20)
 }
 
+// nolint:unused
 func (s *testStatsSuite) prepareForGlobalStatsWithOpts(c *C, tk *testkit.TestKit, tblName, dbName string) {
 	tk.MustExec("create database if not exists " + dbName)
 	tk.MustExec("use " + dbName)
@@ -870,6 +871,7 @@ func (s *testStatsSuite) prepareForGlobalStatsWithOpts(c *C, tk *testkit.TestKit
 	c.Assert(s.do.StatsHandle().DumpStatsDeltaToKV(handle.DumpAll), IsNil)
 }
 
+// nolint:unused
 func (s *testStatsSuite) checkForGlobalStatsWithOpts(c *C, tk *testkit.TestKit, p string, topn, buckets int) {
 	delta := buckets/2 + 1
 	for _, isIdx := range []int{0, 1} {
@@ -890,6 +892,7 @@ func (s *testStatsSuite) TestAnalyzeGlobalStatsWithOpts(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	s.prepareForGlobalStatsWithOpts(c, tk, "test_gstats_opt", "test_gstats_opt")
 
+	// nolint:unused
 	type opt struct {
 		topn    int
 		buckets int

structure/type.go

@@ -51,6 +51,7 @@ func (t *TxStructure) encodeStringDataKey(key []byte) kv.Key {
 	return codec.EncodeUint(ek, uint64(StringData))
 }
 
+// nolint:unused
 func (t *TxStructure) encodeHashMetaKey(key []byte) kv.Key {
 	ek := make([]byte, 0, len(t.prefix)+codec.EncodedBytesLength(len(key))+8)
 	ek = append(ek, t.prefix...)