opt: simplify ScalarBuilder.Build

pkg/sql/opt/idxconstraint/index_constraints_test.go

@@ -120,10 +120,10 @@ func TestIndexConstraints(t *testing.T) {
 					computedCols = make(map[opt.ColumnID]opt.ScalarExpr)
 					for col, expr := range sv.ComputedCols() {
 						b := optbuilder.NewScalar(context.Background(), &semaCtx, &evalCtx, &f)
-						if err := b.Build(expr); err != nil {
+						computedColExpr, err := b.Build(expr)
+						if err != nil {
 							d.Fatalf(t, "error building computed column expression: %v", err)
 						}
-						computedColExpr := f.Memo().RootExpr().(opt.ScalarExpr)
 						computedCols[col] = computedColExpr
 						var sharedProps props.Shared
 						memo.BuildSharedProps(computedColExpr, &sharedProps, &evalCtx)
@@ -314,10 +314,10 @@ func buildFilters(
 		return memo.FiltersExpr{}, err
 	}
 	b := optbuilder.NewScalar(context.Background(), semaCtx, evalCtx, f)
-	if err := b.Build(expr); err != nil {
+	root, err := b.Build(expr)
+	if err != nil {
 		return memo.FiltersExpr{}, err
 	}
-	root := f.Memo().RootExpr().(opt.ScalarExpr)
 	if _, ok := root.(*memo.TrueExpr); ok {
 		return memo.TrueFilter, nil
 	}

pkg/sql/opt/lookupjoin/constraint_builder_test.go

@@ -103,10 +103,10 @@ func TestLookupConstraints(t *testing.T) {
 							return 0, opt.ColSet{}, err
 						}
 						b := optbuilder.NewScalar(context.Background(), &semaCtx, &evalCtx, &f)
-						if err := b.Build(expr); err != nil {
+						compExpr, err := b.Build(expr)
+						if err != nil {
 							return 0, opt.ColSet{}, err
 						}
-						compExpr := f.Memo().RootExpr().(opt.ScalarExpr)
 						var sharedProps props.Shared
 						memo.BuildSharedProps(compExpr, &sharedProps, &evalCtx)
 						md.TableMeta(tableID).AddComputedCol(colID, compExpr, sharedProps.OuterCols)
@@ -312,12 +312,11 @@ func makeFiltersExpr(
 	}
 
 	b := optbuilder.NewScalar(context.Background(), semaCtx, evalCtx, f)
-	if err := b.Build(expr); err != nil {
+	root, err := b.Build(expr)
+	if err != nil {
 		return nil, err
 	}
 
-	root := f.Memo().RootExpr().(opt.ScalarExpr)
-
 	return memo.FiltersExpr{f.ConstructFiltersItem(root)}, nil
 }
 

pkg/sql/opt/memo/expr_test.go

@@ -17,7 +17,6 @@ import (
 	"testing"
 
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
-	"github.com/cockroachdb/cockroach/pkg/sql/opt"
 	"github.com/cockroachdb/cockroach/pkg/sql/opt/memo"
 	"github.com/cockroachdb/cockroach/pkg/sql/opt/optbuilder"
 	"github.com/cockroachdb/cockroach/pkg/sql/opt/testutils"
@@ -93,11 +92,11 @@ func TestExprIsNeverNull(t *testing.T) {
 				}
 
 				b := optbuilder.NewScalar(ctx, &semaCtx, &evalCtx, o.Factory())
-				err = b.Build(expr)
+				scalar, err := b.Build(expr)
 				if err != nil {
 					return fmt.Sprintf("error: %s\n", strings.TrimSpace(err.Error()))
 				}
-				result := memo.ExprIsNeverNull(o.Memo().RootExpr().(opt.ScalarExpr), sv.NotNullCols())
+				result := memo.ExprIsNeverNull(scalar, sv.NotNullCols())
 				return fmt.Sprintf("%t\n", result)
 
 			default:

pkg/sql/opt/memo/memo.go

@@ -315,12 +315,6 @@ func (m *Memo) SetRoot(e RelExpr, phys *physical.Required) {
 	}
 }
 
-// SetScalarRoot stores the root memo expression when it is a scalar expression.
-// Used only for testing.
-func (m *Memo) SetScalarRoot(scalar opt.ScalarExpr) {
-	m.rootExpr = scalar
-}
-
 // HasPlaceholders returns true if the memo contains at least one placeholder
 // operator.
 func (m *Memo) HasPlaceholders() bool {

pkg/sql/opt/memo/memo_test.go

@@ -97,10 +97,11 @@ func TestCompositeSensitive(t *testing.T) {
 		}
 
 		b := optbuilder.NewScalar(context.Background(), &semaCtx, &evalCtx, &f)
-		if err := b.Build(expr); err != nil {
+		scalar, err := b.Build(expr)
+		if err != nil {
 			d.Fatalf(t, "error building: %v", err)
 		}
-		return fmt.Sprintf("%v", memo.CanBeCompositeSensitive(md, f.Memo().RootExpr()))
+		return fmt.Sprintf("%v", memo.CanBeCompositeSensitive(md, scalar))
 	})
 }
 

pkg/sql/opt/optbuilder/builder_test.go

@@ -112,14 +112,14 @@ func TestBuilder(t *testing.T) {
 				// of the build process.
 				o.DisableOptimizations()
 				b := optbuilder.NewScalar(ctx, &semaCtx, &evalCtx, o.Factory())
-				err = b.Build(expr)
+				scalar, err := b.Build(expr)
 				if err != nil {
 					return fmt.Sprintf("error: %s\n", strings.TrimSpace(err.Error()))
 				}
 				f := memo.MakeExprFmtCtx(
 					ctx, tester.Flags.ExprFormat, false /* redactableValues */, o.Memo(), catalog,
 				)
-				f.FormatExpr(o.Memo().RootExpr())
+				f.FormatExpr(scalar)
 				return f.Buffer.String()
 
 			default:

pkg/sql/opt/optbuilder/scalar.go

@@ -1177,7 +1177,7 @@ func NewScalar(
 
 // Build a memo structure from a TypedExpr: the root group represents a scalar
 // expression equivalent to expr.
-func (sb *ScalarBuilder) Build(expr tree.Expr) (err error) {
+func (sb *ScalarBuilder) Build(expr tree.Expr) (_ opt.ScalarExpr, err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			// This code allows us to propagate errors without adding lots of checks
@@ -1194,8 +1194,7 @@ func (sb *ScalarBuilder) Build(expr tree.Expr) (err error) {
 
 	typedExpr := sb.scope.resolveType(expr, types.Any)
 	scalar := sb.buildScalar(typedExpr, &sb.scope, nil, nil, nil)
-	sb.factory.Memo().SetScalarRoot(scalar)
-	return nil
+	return scalar, nil
 }
 
 // reType is similar to tree.ReType, except that it panics with an internal

pkg/sql/opt/partialidx/implicator_test.go

@@ -370,11 +370,10 @@ func makeFiltersExpr(
 	}
 
 	b := optbuilder.NewScalar(context.Background(), semaCtx, evalCtx, f)
-	if err := b.Build(expr); err != nil {
+	root, err := b.Build(expr)
+	if err != nil {
 		return nil, err
 	}
 
-	root := f.Memo().RootExpr().(opt.ScalarExpr)
-
 	return memo.FiltersExpr{f.ConstructFiltersItem(root)}, nil
 }

pkg/sql/opt/testutils/build.go

@@ -57,11 +57,12 @@ func BuildScalar(
 	}
 
 	b := optbuilder.NewScalar(context.Background(), semaCtx, evalCtx, f)
-	if err := b.Build(expr); err != nil {
+	root, err := b.Build(expr)
+	if err != nil {
 		t.Fatal(err)
 	}
 
-	return f.Memo().RootExpr().(opt.ScalarExpr)
+	return root
 }
 
 // BuildFilters builds the given input string as a FiltersExpr and returns it.

pkg/sql/sem/eval/eval_test.go

@@ -100,12 +100,13 @@ func optBuildScalar(evalCtx *eval.Context, e tree.Expr) (tree.TypedExpr, error)
 	o.Init(ctx, evalCtx, nil /* catalog */)
 	semaCtx := tree.MakeSemaContext()
 	b := optbuilder.NewScalar(ctx, &semaCtx, evalCtx, o.Factory())
-	if err := b.Build(e); err != nil {
+	scalar, err := b.Build(e)
+	if err != nil {
 		return nil, err
 	}
 
 	bld := execbuilder.New(
-		ctx, nil /* factory */, &o, o.Memo(), nil /* catalog */, o.Memo().RootExpr(),
+		ctx, nil /* factory */, &o, o.Memo(), nil /* catalog */, scalar,
 		evalCtx, false, /* allowAutoCommit */
 		false, /* isANSIDML */
 	)