linter: find inappropriate key in call to context.WithValue

build/BUILD.bazel

@@ -55,6 +55,7 @@ STATICHECK_ANALYZERS = [
     "S1039",
     "S1040",
     "SA1019",
+    "SA1029",
     "SA2000",
     "SA2001",
     "SA2003",

build/nogo_config.json

@@ -773,6 +773,13 @@
       "meta": "meta code"
     }
   },
+  "SA1029": {
+    "exclude_files": {
+      "/external/": "no need to vet third party code",
+      ".*_generated\\.go$": "ignore generated code",
+      ".*_test\\.go$": "ignore test code"
+    }
+  },
   "SA2000": {
     "exclude_files": {
       "external/": "no need to vet third party code",

executor/memtable_reader_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/pingcap/failpoint"
 	"github.com/pingcap/fn"
 	"github.com/pingcap/sysutil"
+	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/testkit"
 	"github.com/pingcap/tidb/util/pdapi"
 	pmodel "github.com/prometheus/common/model"
@@ -56,7 +57,7 @@ func TestMetricTableData(t *testing.T) {
 	}
 	matrix = append(matrix, &pmodel.SampleStream{Metric: metric, Values: []pmodel.SamplePair{v1}})
 
-	ctx := context.WithValue(context.Background(), "__mockMetricsPromData", matrix)
+	ctx := context.WithValue(context.Background(), executor.MockMetricsPromDataKey{}, matrix)
 	ctx = failpoint.WithHook(ctx, func(ctx context.Context, fpname string) bool {
 		return fpname == fpName
 	})

executor/metrics_reader.go

@@ -89,9 +89,12 @@ func (e *MetricRetriever) retrieve(ctx context.Context, sctx sessionctx.Context)
 	return totalRows, nil
 }
 
+// MockMetricsPromDataKey is for test
+type MockMetricsPromDataKey struct{}
+
 func (e *MetricRetriever) queryMetric(ctx context.Context, sctx sessionctx.Context, queryRange promv1.Range, quantile float64) (result pmodel.Value, err error) {
 	failpoint.InjectContext(ctx, "mockMetricsPromData", func() {
-		failpoint.Return(ctx.Value("__mockMetricsPromData").(pmodel.Matrix), nil)
+		failpoint.Return(ctx.Value(MockMetricsPromDataKey{}).(pmodel.Matrix), nil)
 	})
 
 	// Add retry to avoid network error.

executor/slow_query.go

@@ -52,6 +52,8 @@ import (
 	"golang.org/x/exp/slices"
 )
 
+type signalsKey struct{}
+
 // ParseSlowLogBatchSize is the batch size of slow-log lines for a worker to parse, exported for testing.
 var ParseSlowLogBatchSize = 64
 
@@ -474,7 +476,7 @@ func (e *slowQueryRetriever) parseSlowLog(ctx context.Context, sctx sessionctx.C
 		}
 		failpoint.Inject("mockReadSlowLogSlow", func(val failpoint.Value) {
 			if val.(bool) {
-				signals := ctx.Value("signals").([]chan int)
+				signals := ctx.Value(signalsKey{}).([]chan int)
 				signals[0] <- 1
 				<-signals[1]
 			}

executor/slow_query_test.go

@@ -666,7 +666,7 @@ select * from t;`
 	retriever, err := newSlowQueryRetriever()
 	require.NoError(t, err)
 	var signal1, signal2 = make(chan int, 1), make(chan int, 1)
-	ctx := context.WithValue(context.Background(), "signals", []chan int{signal1, signal2})
+	ctx := context.WithValue(context.Background(), signalsKey{}, []chan int{signal1, signal2})
 	ctx, cancel := context.WithCancel(ctx)
 	err = failpoint.Enable("github.com/pingcap/tidb/executor/mockReadSlowLogSlow", "return(true)")
 	require.NoError(t, err)

store/gcworker/gc_worker.go

@@ -1198,6 +1198,7 @@ func (w *GCWorker) resolveLocksForRange(
 	failpoint.Inject("setGcResolveMaxBackoff", func(v failpoint.Value) {
 		sleep := v.(int)
 		// cooperate with github.com/tikv/client-go/v2/locate/invalidCacheAndRetry
+		//nolint: SA1029
 		ctx = context.WithValue(ctx, "injectedBackoff", struct{}{})
 		bo = tikv.NewBackofferWithVars(ctx, sleep, nil)
 	})

ttl/metrics/metrics.go

@@ -133,16 +133,16 @@ func (t *PhaseTracer) EndPhase() {
 	t.EnterPhase("")
 }
 
-const ttlPhaseTraceKey = "ttlPhaseTraceKey"
+type ttlPhaseTraceKey struct{}
 
 // CtxWithPhaseTracer create a new context with tracer
 func CtxWithPhaseTracer(ctx context.Context, tracer *PhaseTracer) context.Context {
-	return context.WithValue(ctx, ttlPhaseTraceKey, tracer)
+	return context.WithValue(ctx, ttlPhaseTraceKey{}, tracer)
 }
 
 // PhaseTracerFromCtx returns a tracer from a given context
 func PhaseTracerFromCtx(ctx context.Context) *PhaseTracer {
-	if tracer, ok := ctx.Value(ttlPhaseTraceKey).(*PhaseTracer); ok {
+	if tracer, ok := ctx.Value(ttlPhaseTraceKey{}).(*PhaseTracer); ok {
 		return tracer
 	}
 	return nil