Makefile: add staticcheck (pingcap#14420)

Makefile

@@ -30,6 +30,7 @@ GOBUILD         := $(GO) build $(BUILD_FLAG) -tags codes
 GOBUILDCOVERAGE := GOPATH=$(GOPATH) cd tidb-server; $(GO) test -coverpkg="../..." -c .
 GOTEST          := $(GO) test -p $(P)
 OVERALLS        := GO111MODULE=on overalls
+STATICCHECK     := GO111MODULE=on staticcheck
 
 ARCH      := "`uname -s`"
 LINUX     := "Linux"
@@ -81,7 +82,7 @@ build:
 # Install the check tools.
 check-setup:tools/bin/revive tools/bin/goword tools/bin/gometalinter tools/bin/gosec
 
-check: fmt errcheck lint tidy testSuite check-static vet
+check: fmt errcheck lint tidy testSuite check-static vet staticcheck
 
 # These need to be fixed before they can be ran regularly
 check-fail: goword check-slow
@@ -123,6 +124,10 @@ vet:
 	@echo "vet"
 	$(GO) vet -all $(PACKAGES) 2>&1 | $(FAIL_ON_STDOUT)
 
+staticcheck:
+	$(GO) get honnef.co/go/tools/cmd/staticcheck
+	$(STATICCHECK) ./...
+
 tidy:
 	@echo "go mod tidy"
 	./tools/check/check-tidy.sh

ddl/column_test.go

@@ -630,7 +630,7 @@ func (s *testColumnSuite) checkReorganizationColumn(ctx sessionctx.Context, d *d
 	return nil
 }
 
-func (s *testColumnSuite) checkPublicColumn(ctx sessionctx.Context, d *ddl, tblInfo *model.TableInfo, handle int64, newCol *table.Column, oldRow []types.Datum, columnValue interface{}) error {
+func (s *testColumnSuite) checkPublicColumn(ctx sessionctx.Context, d *ddl, tblInfo *model.TableInfo, _ int64, newCol *table.Column, oldRow []types.Datum, columnValue interface{}) error {
 	t, err := testGetTableWithError(d, s.dbInfo.ID, tblInfo.ID)
 	if err != nil {
 		return errors.Trace(err)
@@ -663,7 +663,7 @@ func (s *testColumnSuite) checkPublicColumn(ctx sessionctx.Context, d *ddl, tblI
 	}
 
 	newRow := types.MakeDatums(int64(11), int64(22), int64(33), int64(44))
-	handle, err = t.AddRecord(ctx, newRow)
+	handle, err := t.AddRecord(ctx, newRow)
 	if err != nil {
 		return errors.Trace(err)
 	}

ddl/db_test.go

@@ -2228,7 +2228,7 @@ func (s *testDBSuite5) TestRepairTable(c *C) {
 }
 
 func turnRepairModeAndInit(on bool) {
-	list := make([]string, 0, 0)
+	list := make([]string, 0)
 	if on {
 		list = append(list, "test.origin")
 	}

executor/hash_table.go

@@ -162,8 +162,7 @@ func (c *hashRowContainer) PutChunk(chk *chunk.Chunk) error {
 // key of hash table: hash value of key columns
 // value of hash table: RowPtr of the corresponded row
 func (c *hashRowContainer) PutChunkSelected(chk *chunk.Chunk, selected []bool) error {
-	var chkIdx uint32
-	chkIdx = uint32(c.rowContainer.NumChunks())
+	chkIdx := uint32(c.rowContainer.NumChunks())
 	err := c.rowContainer.Add(chk)
 	if err != nil {
 		return err

executor/index_merge_reader.go

@@ -544,8 +544,7 @@ func (w *partialIndexWorker) fetchHandles(ctx context.Context, result distsql.Se
 			}
 		}
 	}()
-	var chk *chunk.Chunk
-	chk = chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeLonglong)}, w.maxChunkSize)
+	chk := chunk.NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeLonglong)}, w.maxChunkSize)
 	for {
 		handles, retChunk, err := w.extractTaskHandles(ctx, chk, result)
 		if err != nil {

expression/bench_test.go

@@ -1256,8 +1256,7 @@ func testVectorizedBuiltinFunc(c *C, vecExprCases vecExprBenchCases) {
 					c.Assert(err, IsNil, commentf(i))
 					c.Assert(isNull, Equals, output.IsNull(i), commentf(i))
 					if !isNull {
-						var cmp int
-						cmp = json.CompareBinary(val, output.GetJSON(i))
+						cmp := json.CompareBinary(val, output.GetJSON(i))
 						c.Assert(cmp, Equals, 0, commentf(i))
 					}
 					i++

expression/partition_pruner.go

@@ -163,7 +163,7 @@ func (p *hashPartitionPruner) solve(ctx sessionctx.Context, conds []Expression,
 	for _, col := range ExtractColumns(piExpr) {
 		p.insertCol(col)
 	}
-	p.constantMap = make([]*Constant, p.numColumn, p.numColumn)
+	p.constantMap = make([]*Constant, p.numColumn)
 	conflict := p.reduceConstantEQ()
 	if conflict {
 		return 0, false, conflict

planner/core/encode.go

@@ -108,7 +108,7 @@ func NormalizePlan(p Plan) (normalized, digest string) {
 	d := digesterPool.Get().(*planDigester)
 	defer digesterPool.Put(d)
 	d.normalizePlanTree(selectPlan)
-	normalized = string(d.buf.Bytes())
+	normalized = d.buf.String()
 	d.hasher.Write(d.buf.Bytes())
 	d.buf.Reset()
 	digest = fmt.Sprintf("%x", d.hasher.Sum(nil))

planner/core/exhaust_physical_plans.go

@@ -1174,13 +1174,13 @@ func (ijHelper *indexJoinBuildHelper) buildTemplateRange(matchedKeyCnt int, eqAn
 	} else if haveExtraCol {
 		// Reserve a position for the last col.
 		ranges = append(ranges, &ranger.Range{
-			LowVal:  make([]types.Datum, pointLength+1, pointLength+1),
-			HighVal: make([]types.Datum, pointLength+1, pointLength+1),
+			LowVal:  make([]types.Datum, pointLength+1),
+			HighVal: make([]types.Datum, pointLength+1),
 		})
 	} else {
 		ranges = append(ranges, &ranger.Range{
-			LowVal:  make([]types.Datum, pointLength, pointLength),
-			HighVal: make([]types.Datum, pointLength, pointLength),
+			LowVal:  make([]types.Datum, pointLength),
+			HighVal: make([]types.Datum, pointLength),
 		})
 	}
 	sc := ijHelper.join.ctx.GetSessionVars().StmtCtx

planner/core/find_best_task.go

@@ -249,7 +249,7 @@ func compareBool(l, r bool) int {
 	if l == r {
 		return 0
 	}
-	if l == false {
+	if !l {
 		return -1
 	}
 	return 1

planner/core/rule_partition_processor.go

@@ -154,7 +154,7 @@ func (s *partitionProcessor) pruneHashPartition(ds *DataSource, pi *model.Partit
 		// Constant false.
 		if con, ok := filterConds[0].(*expression.Constant); ok && con.DeferredExpr == nil && con.ParamMarker == nil {
 			ret, _, err := expression.EvalBool(sctx, expression.CNFExprs{con}, chunk.Row{})
-			if err == nil && ret == false {
+			if err == nil && !ret {
 				alwaysFalse = true
 			}
 		}
@@ -234,7 +234,7 @@ func (s *partitionProcessor) prune(ds *DataSource) (LogicalPlan, error) {
 			// Constant false.
 			if con, ok := filterConds[0].(*expression.Constant); ok && con.DeferredExpr == nil && con.ParamMarker == nil {
 				ret, _, err := expression.EvalBool(sctx, expression.CNFExprs{con}, chunk.Row{})
-				if err == nil && ret == false {
+				if err == nil && !ret {
 					alwaysFalse = true
 				}
 			}
@@ -313,7 +313,7 @@ func (s *partitionProcessor) canBePruned(sctx sessionctx.Context, partCol *expre
 		// Constant false.
 		if con, ok := conds[0].(*expression.Constant); ok && con.DeferredExpr == nil && con.ParamMarker == nil {
 			ret, _, err := expression.EvalBool(sctx, expression.CNFExprs{con}, chunk.Row{})
-			if err == nil && ret == false {
+			if err == nil && !ret {
 				return true, nil
 			}
 		}

staticcheck.conf

@@ -0,0 +1,10 @@
+checks = ["S1002","S1004","S1007","S1009","S1010","S1012","S1019","S1020","S1021","S1024","S1030","SA2*","SA3*","SA4009","SA5*","SA6000","SA6001","SA6005", "-SA2002"]
+initialisms = ["ACL", "API", "ASCII", "CPU", "CSS", "DNS",
+	"EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID",
+	"IP", "JSON", "QPS", "RAM", "RPC", "SLA",
+	"SMTP", "SQL", "SSH", "TCP", "TLS", "TTL",
+	"UDP", "UI", "GID", "UID", "UUID", "URI",
+	"URL", "UTF8", "VM", "XML", "XMPP", "XSRF",
+	"XSS"]
+dot_import_whitelist = []
+http_status_code_whitelist = ["200", "400", "404", "500"]

store/tikv/2pc_test.go

@@ -673,7 +673,7 @@ func (s *testCommitterSuite) TestAcquireFalseTimeoutLock(c *C) {
 	lockCtx = &kv.LockCtx{ForUpdateTS: txn2.startTS, LockWaitTime: kv.LockNoWait, WaitStartTime: time.Now()}
 	startTime := time.Now()
 	err = txn2.LockKeys(context.Background(), lockCtx, k2)
-	elapsed := time.Now().Sub(startTime)
+	elapsed := time.Since(startTime)
 	// cannot acquire lock immediately thus error
 	c.Assert(err.Error(), Equals, ErrLockAcquireFailAndNoWaitSet.Error())
 	// it should return immediately
@@ -683,7 +683,7 @@ func (s *testCommitterSuite) TestAcquireFalseTimeoutLock(c *C) {
 	lockCtx = &kv.LockCtx{ForUpdateTS: txn2.startTS, LockWaitTime: 300, WaitStartTime: time.Now()}
 	startTime = time.Now()
 	err = txn2.LockKeys(context.Background(), lockCtx, k2)
-	elapsed = time.Now().Sub(startTime)
+	elapsed = time.Since(startTime)
 	// cannot acquire lock in time thus error
 	c.Assert(err.Error(), Equals, ErrLockWaitTimeout.Error())
 	// it should return after about 300ms

store/tikv/coprocessor_cache.go

@@ -152,7 +152,7 @@ func (c *coprCache) Get(key []byte) *coprCacheValue {
 	}
 	typedValue := value.(*coprCacheValue)
 	// ristretto does not handle hash collision, so check the key equality after getting a value.
-	if bytes.Compare(typedValue.Key, key) != 0 {
+	if !bytes.Equal(typedValue.Key, key) {
 		return nil
 	}
 	return typedValue

util/stmtsummary/statement_summary.go

@@ -608,7 +608,7 @@ func newStmtSummaryByDigestElement(sei *StmtExecInfo, beginTime int64, intervalS
 		minLatency:   sei.TotalLatency,
 		firstSeen:    sei.StartTime,
 		lastSeen:     sei.StartTime,
-		backoffTypes: make(map[fmt.Stringer]int, 0),
+		backoffTypes: make(map[fmt.Stringer]int),
 	}
 	ssElement.add(sei, intervalSeconds)
 	return ssElement