sql: rename NullableArgs to CalledOnNullInput

Previously, the `Overload.NullableArgs` boolean indicated whether or not
a function was evaluated in the presence of `NULL` inputs. This name was
confusing because it did not describe the behavior of the function.
Arguments to all functions can be `NULL` (i.e., "nullable") so the
difference between `NullableArgs` being `true` and `false` was unclear
without reading the detailed description of the field.

This commit renames the field, and all related variables throughout the
codebase, to `CalledOnNullInput`, making it clear that `true` indicates
that the function is called if any inputs are `NULL`, and `false`
indicates that the function is not called if any inputs are `NULL`. This
name also maps more closely to SQL syntax such as
`CREATE FUNCTION ... CALLED ON NULL INPUT ...`.

Release note: None

pkg/sql/catalog/funcdesc/func_desc.go

@@ -488,7 +488,7 @@ func (desc *immutable) ToOverload() (ret *tree.Overload, err error) {
 	if err != nil {
 		return nil, err
 	}
-	ret.NullableArgs, err = desc.getOverloadNullableArgs()
+	ret.CalledOnNullInput, err = desc.calledOnNullInput()
 	if err != nil {
 		return nil, err
 	}
@@ -517,7 +517,10 @@ func (desc *immutable) getOverloadVolatility() (volatility.V, error) {
 	return ret, nil
 }
 
-func (desc *immutable) getOverloadNullableArgs() (bool, error) {
+// calledOnNullInput returns true if the function should be called when any of
+// its input arguments are NULL. See Overload.CalledOnNullInput for more
+// details.
+func (desc *immutable) calledOnNullInput() (bool, error) {
 	switch desc.NullInputBehavior {
 	case catpb.Function_CALLED_ON_NULL_INPUT:
 		return true, nil

pkg/sql/catalog/funcdesc/func_desc_test.go

@@ -544,7 +544,7 @@ func TestToOverload(t *testing.T) {
 			},
 		},
 		{
-			// Test NullableArgs matters.
+			// Test CalledOnNullInput matters.
 			desc: descpb.FunctionDescriptor{
 				ID:                1,
 				Args:              []descpb.FunctionDescriptor_Argument{{Name: "arg1", Type: types.Int}},
@@ -559,12 +559,12 @@ func TestToOverload(t *testing.T) {
 				Types: tree.ArgTypes{
 					{Name: "arg1", Typ: types.Int},
 				},
-				ReturnType:   tree.FixedReturnType(types.Int),
-				ReturnSet:    true,
-				Volatility:   volatility.Leakproof,
-				Body:         "ANY QUERIES",
-				IsUDF:        true,
-				NullableArgs: true,
+				ReturnType:        tree.FixedReturnType(types.Int),
+				ReturnSet:         true,
+				Volatility:        volatility.Leakproof,
+				Body:              "ANY QUERIES",
+				IsUDF:             true,
+				CalledOnNullInput: true,
 			},
 		},
 		{

pkg/sql/colexec/builtin_funcs.go

@@ -70,7 +70,7 @@ func (b *defaultBuiltinFuncOperator) Next() coldata.Batch {
 					err error
 				)
 				// Some functions cannot handle null arguments.
-				if hasNulls && !b.funcExpr.ResolvedOverload().NullableArgs {
+				if hasNulls && !b.funcExpr.ResolvedOverload().CalledOnNullInput {
 					res = tree.DNull
 				} else {
 					res, err = b.funcExpr.ResolvedOverload().

pkg/sql/colexec/colbuilder/execplan.go

@@ -2040,7 +2040,7 @@ func planProjectionOperators(
 		}
 		return planProjectionExpr(
 			ctx, evalCtx, t.Operator, t.ResolvedType(), leftExpr, rightExpr,
-			columnTypes, input, acc, factory, t.Op.EvalOp, nil /* cmpExpr */, releasables, t.Op.NullableArgs,
+			columnTypes, input, acc, factory, t.Op.EvalOp, nil /* cmpExpr */, releasables, t.Op.CalledOnNullInput,
 		)
 	case *tree.CaseExpr:
 		allocator := colmem.NewAllocator(ctx, acc, factory)
@@ -2191,7 +2191,7 @@ func planProjectionOperators(
 	case *tree.ComparisonExpr:
 		return planProjectionExpr(
 			ctx, evalCtx, t.Operator, t.ResolvedType(), t.TypedLeft(), t.TypedRight(),
-			columnTypes, input, acc, factory, nil /* binFn */, t, releasables, t.Op.NullableArgs,
+			columnTypes, input, acc, factory, nil /* binFn */, t, releasables, t.Op.CalledOnNullInput,
 		)
 	case tree.Datum:
 		op, err = projectDatum(t)
@@ -2358,7 +2358,7 @@ func planProjectionExpr(
 	binOp tree.BinaryEvalOp,
 	cmpExpr *tree.ComparisonExpr,
 	releasables *[]execreleasable.Releasable,
-	nullableArgs bool,
+	calledOnNullInput bool,
 ) (op colexecop.Operator, resultIdx int, typs []*types.T, err error) {
 	if err := checkSupportedProjectionExpr(left, right); err != nil {
 		return nil, resultIdx, typs, err
@@ -2395,7 +2395,7 @@ func planProjectionExpr(
 		// appended to the input batch.
 		op, err = colexecprojconst.GetProjectionLConstOperator(
 			allocator, typs, left.ResolvedType(), outputType, projOp, input,
-			rightIdx, lConstArg, resultIdx, evalCtx, binOp, cmpExpr, nullableArgs,
+			rightIdx, lConstArg, resultIdx, evalCtx, binOp, cmpExpr, calledOnNullInput,
 		)
 	} else {
 		var leftIdx int
@@ -2472,7 +2472,7 @@ func planProjectionExpr(
 				// all other projection operators.
 				op, err = colexecprojconst.GetProjectionRConstOperator(
 					allocator, typs, right.ResolvedType(), outputType, projOp,
-					input, leftIdx, rConstArg, resultIdx, evalCtx, binOp, cmpExpr, nullableArgs,
+					input, leftIdx, rConstArg, resultIdx, evalCtx, binOp, cmpExpr, calledOnNullInput,
 				)
 			}
 		} else {
@@ -2487,7 +2487,7 @@ func planProjectionExpr(
 			resultIdx = len(typs)
 			op, err = colexecproj.GetProjectionOperator(
 				allocator, typs, outputType, projOp, input, leftIdx, rightIdx,
-				resultIdx, evalCtx, binOp, cmpExpr, nullableArgs,
+				resultIdx, evalCtx, binOp, cmpExpr, calledOnNullInput,
 			)
 		}
 	}

pkg/sql/colexec/colexeccmp/default_cmp_expr.go

@@ -38,7 +38,7 @@ func NewComparisonExprAdapter(
 			expr:               expr,
 		}
 	}
-	nullable := expr.Op.NullableArgs
+	nullable := expr.Op.CalledOnNullInput
 	_, _, _, flipped, negate := tree.FoldComparisonExpr(op, nil /* left */, nil /* right */)
 	if nullable {
 		if flipped {

pkg/sql/colexec/colexeccmp/default_cmp_expr_tmpl.go

@@ -41,7 +41,7 @@ type _EXPR_NAME struct {
 var _ ComparisonExprAdapter = &_EXPR_NAME{}
 
 func (c *_EXPR_NAME) Eval(left, right tree.Datum) (tree.Datum, error) {
-	// {{if not .NullableArgs}}
+	// {{if not .CalledOnNullInput}}
 	if left == tree.DNull || right == tree.DNull {
 		return tree.DNull, nil
 	}