eval: mark stored context.Context as deprecated

This commit unexports the stored `context.Context` from `eval.Context`,
marks it as "deprecated" and provides getter/setter methods for now.
There are just two places that still use it - namely
`eval.Context.MustGetPlaceholderValue` and `eval.UnwrapDatum` (when
unwrapping a placeholder), and refactoring those is extremely difficult
since the amount of plumbing required is probably thousands of line
changes without an easy way to automate that. In order to not lose
progress on the removal achieved in the previous commits we do this
deprecation.

The next step for the complete removal is to do analysis of the web of
callsites of these two methods to see whether we have incorrect
layering, and this will be done separately.

Release note: None

pkg/sql/conn_executor.go

@@ -2813,7 +2813,7 @@ func (ex *connExecutor) resetEvalCtx(evalCtx *extendedEvalContext, txn *kv.Txn,
 	evalCtx.Placeholders = nil
 	evalCtx.Annotations = nil
 	evalCtx.IVarContainer = nil
-	evalCtx.Context.Context = ex.Ctx()
+	evalCtx.SetDeprecatedContext(ex.Ctx())
 	evalCtx.Txn = txn
 	evalCtx.PrepareOnly = false
 	evalCtx.SkipNormalize = false

pkg/sql/distsql/server.go

@@ -360,18 +360,15 @@ func (ds *ServerImpl) setupFlow(
 			return nil, nil, nil, err
 		}
 		evalCtx = &eval.Context{
-			Settings:         ds.ServerConfig.Settings,
-			SessionDataStack: sessiondata.NewStack(sd),
-			ClusterID:        ds.ServerConfig.LogicalClusterID.Get(),
-			ClusterName:      ds.ServerConfig.ClusterName,
-			NodeID:           ds.ServerConfig.NodeID,
-			Codec:            ds.ServerConfig.Codec,
-			ReCache:          ds.regexpCache,
-			Locality:         ds.ServerConfig.Locality,
-			Tracer:           ds.ServerConfig.Tracer,
-			// Most processors will override this Context with their own context in
-			// ProcessorBase. StartInternal().
-			Context:                   ctx,
+			Settings:                  ds.ServerConfig.Settings,
+			SessionDataStack:          sessiondata.NewStack(sd),
+			ClusterID:                 ds.ServerConfig.LogicalClusterID.Get(),
+			ClusterName:               ds.ServerConfig.ClusterName,
+			NodeID:                    ds.ServerConfig.NodeID,
+			Codec:                     ds.ServerConfig.Codec,
+			ReCache:                   ds.regexpCache,
+			Locality:                  ds.ServerConfig.Locality,
+			Tracer:                    ds.ServerConfig.Tracer,
 			Planner:                   &faketreeeval.DummyEvalPlanner{Monitor: monitor},
 			PrivilegedAccessor:        &faketreeeval.DummyPrivilegedAccessor{},
 			SessionAccessor:           &faketreeeval.DummySessionAccessor{},
@@ -386,6 +383,9 @@ func (ds *ServerImpl) setupFlow(
 			IndexUsageStatsController: ds.ServerConfig.IndexUsageStatsController,
 			RangeStatsFetcher:         ds.ServerConfig.RangeStatsFetcher,
 		}
+		// Most processors will override this Context with their own context in
+		// ProcessorBase. StartInternal().
+		evalCtx.SetDeprecatedContext(ctx)
 		evalCtx.SetStmtTimestamp(timeutil.Unix(0 /* sec */, req.EvalContext.StmtTimestampNanos))
 		evalCtx.SetTxnTimestamp(timeutil.Unix(0 /* sec */, req.EvalContext.TxnTimestampNanos))
 	}

pkg/sql/execinfra/processorsbase.go

@@ -868,8 +868,8 @@ func (pb *ProcessorBaseNoHelper) StartInternal(ctx context.Context, name string)
 			pb.span.SetTag(execinfrapb.ProcessorIDTagKey, attribute.IntValue(int(pb.ProcessorID)))
 		}
 	}
-	pb.evalOrigCtx = pb.EvalCtx.Context
-	pb.EvalCtx.Context = pb.Ctx
+	pb.evalOrigCtx = pb.EvalCtx.GetDeprecatedContext()
+	pb.EvalCtx.SetDeprecatedContext(pb.Ctx)
 	return pb.Ctx
 }
 
@@ -900,7 +900,7 @@ func (pb *ProcessorBaseNoHelper) InternalClose() bool {
 	// Reset the context so that any incidental uses after this point do not
 	// access the finished span.
 	pb.Ctx = pb.origCtx
-	pb.EvalCtx.Context = pb.evalOrigCtx
+	pb.EvalCtx.SetDeprecatedContext(pb.evalOrigCtx)
 	return true
 }
 

pkg/sql/importer/import_table_creation.go

@@ -156,14 +156,14 @@ func MakeSimpleTableDescriptor(
 	create.Defs = filteredDefs
 
 	evalCtx := eval.Context{
-		Context:            ctx,
 		Sequence:           &importSequenceOperators{},
 		Regions:            makeImportRegionOperator(""),
 		SessionDataStack:   sessiondata.NewStack(&sessiondata.SessionData{}),
 		ClientNoticeSender: &faketreeeval.DummyClientNoticeSender{},
 		TxnTimestamp:       timeutil.Unix(0, walltime),
 		Settings:           st,
 	}
+	evalCtx.SetDeprecatedContext(ctx)
 	affected := make(map[descpb.ID]*tabledesc.Mutable)
 
 	tableDesc, err := sql.NewTableDesc(

pkg/sql/instrumentation.go

@@ -265,7 +265,7 @@ func (ih *instrumentationHelper) Setup(
 			ih.traceMetadata = make(execNodeTraceMetadata)
 		}
 		// Make sure that the builtins use the correct context.
-		ih.evalCtx.Context = newCtx
+		ih.evalCtx.SetDeprecatedContext(newCtx)
 	}()
 
 	if sp := tracing.SpanFromContext(ctx); sp != nil {

pkg/sql/planner.go

@@ -475,7 +475,6 @@ func internalExtendedEvalCtx(
 			TxnReadOnly:                    false,
 			TxnImplicit:                    true,
 			TxnIsSingleStmt:                true,
-			Context:                        ctx,
 			TestingKnobs:                   evalContextTestingKnobs,
 			StmtTimestamp:                  stmtTimestamp,
 			TxnTimestamp:                   txnTimestamp,
@@ -490,6 +489,7 @@ func internalExtendedEvalCtx(
 		Descs:           tables,
 		indexUsageStats: indexUsageStats,
 	}
+	ret.SetDeprecatedContext(ctx)
 	ret.copyFromExecCfg(execCfg)
 	return ret
 }

pkg/sql/row/expr_walker_test.go

@@ -83,9 +83,9 @@ func TestJobBackedSeqChunkProvider(t *testing.T) {
 	defer s.Stopper().Stop(ctx)
 
 	evalCtx := &eval.Context{
-		Context: ctx,
-		Codec:   s.ExecutorConfig().(sql.ExecutorConfig).Codec,
+		Codec: s.ExecutorConfig().(sql.ExecutorConfig).Codec,
 	}
+	evalCtx.SetDeprecatedContext(ctx)
 
 	registry := s.JobRegistry().(*jobs.Registry)
 	testCases := []struct {

pkg/sql/schema_changer.go

@@ -2500,10 +2500,7 @@ func createSchemaChangeEvalCtx(
 		ExecCfg: execCfg,
 		Descs:   descriptors,
 		Context: eval.Context{
-			SessionDataStack: sessiondata.NewStack(sd),
-			// TODO(andrei): This is wrong (just like on the main code path on
-			// setupFlow). Each processor should override Ctx with its own context.
-			Context:            ctx,
+			SessionDataStack:   sessiondata.NewStack(sd),
 			Planner:            &faketreeeval.DummyEvalPlanner{},
 			PrivilegedAccessor: &faketreeeval.DummyPrivilegedAccessor{},
 			SessionAccessor:    &faketreeeval.DummySessionAccessor{},
@@ -2521,6 +2518,9 @@ func createSchemaChangeEvalCtx(
 			Tracer:             execCfg.AmbientCtx.Tracer,
 		},
 	}
+	// TODO(andrei): This is wrong (just like on the main code path on
+	// setupFlow). Each processor should override Ctx with its own context.
+	evalCtx.SetDeprecatedContext(ctx)
 	// The backfill is going to use the current timestamp for the various
 	// functions, like now(), that need it.  It's possible that the backfill has
 	// been partially performed already by another SchemaChangeManager with

pkg/sql/schemachanger/scbuild/tree_context_builder.go

@@ -45,10 +45,9 @@ func (b buildCtx) EvalCtx() *eval.Context {
 }
 
 func newEvalCtx(ctx context.Context, d Dependencies) *eval.Context {
-	return &eval.Context{
+	evalCtx := &eval.Context{
 		ClusterID:          d.ClusterID(),
 		SessionDataStack:   sessiondata.NewStack(d.SessionData()),
-		Context:            ctx,
 		Planner:            &faketreeeval.DummyEvalPlanner{},
 		PrivilegedAccessor: &faketreeeval.DummyPrivilegedAccessor{},
 		SessionAccessor:    &faketreeeval.DummySessionAccessor{},
@@ -59,4 +58,6 @@ func newEvalCtx(ctx context.Context, d Dependencies) *eval.Context {
 		Settings:           d.ClusterSettings(),
 		Codec:              d.Codec(),
 	}
+	evalCtx.SetDeprecatedContext(ctx)
+	return evalCtx
 }

pkg/sql/sem/eval/context.go

@@ -130,8 +130,11 @@ type Context struct {
 	// need to restore once we finish evaluating it.
 	iVarContainerStack []tree.IndexedVarContainer
 
-	// Context holds the context in which the expression is evaluated.
-	Context context.Context
+	// deprecatedContext holds the context in which the expression is evaluated.
+	//
+	// Deprecated: this field should not be used because an effort to remove it
+	// from Context is under way.
+	deprecatedContext context.Context
 
 	Planner Planner
 
@@ -269,6 +272,22 @@ type RangeProber interface {
 	) error
 }
 
+// GetDeprecatedContext returns the context.Context of this Context.
+//
+// Deprecated: this method should not be used because an effort to remove the
+// context.Context from Context is under way.
+func (ec *Context) GetDeprecatedContext() context.Context {
+	return ec.deprecatedContext
+}
+
+// SetDeprecatedContext updates the context.Context of this Context.
+//
+// Deprecated: this method should not be used because an effort to remove the
+// context.Context from Context is under way.
+func (ec *Context) SetDeprecatedContext(ctx context.Context) {
+	ec.deprecatedContext = ctx
+}
+
 // UnwrapDatum encapsulates UnwrapDatum for use in the tree.CompareContext.
 func (ec *Context) UnwrapDatum(d tree.Datum) tree.Datum {
 	return UnwrapDatum(ec, d)
@@ -280,7 +299,7 @@ func (ec *Context) MustGetPlaceholderValue(p *tree.Placeholder) tree.Datum {
 	if !ok {
 		panic(errors.AssertionFailedf("fail"))
 	}
-	out, err := Expr(ec.Context, ec, e)
+	out, err := Expr(ec.deprecatedContext, ec, e)
 	if err != nil {
 		panic(errors.NewAssertionErrorWithWrappedErrf(err, "fail"))
 	}
@@ -315,7 +334,7 @@ func MakeTestingEvalContextWithMon(st *cluster.Settings, monitor *mon.BytesMonit
 	monitor.Start(context.Background(), nil /* pool */, mon.NewStandaloneBudget(math.MaxInt64))
 	ctx.TestingMon = monitor
 	ctx.Planner = &fakePlannerWithMonitor{monitor: monitor}
-	ctx.Context = context.TODO()
+	ctx.deprecatedContext = context.TODO()
 	now := timeutil.Now()
 	ctx.SetTxnTimestamp(now)
 	ctx.SetStmtTimestamp(now)
@@ -641,7 +660,7 @@ func arrayOfType(typ *types.T) (*tree.DArray, error) {
 func UnwrapDatum(evalCtx *Context, d tree.Datum) tree.Datum {
 	d = tree.UnwrapDOidWrapper(d)
 	if p, ok := d.(*tree.Placeholder); ok && evalCtx != nil && evalCtx.HasPlaceholders() {
-		ret, err := Expr(evalCtx.Context, evalCtx, p)
+		ret, err := Expr(evalCtx.deprecatedContext, evalCtx, p)
 		if err != nil {
 			// If we fail to evaluate the placeholder, it's because we don't have
 			// a placeholder available. Just return the placeholder and someone else