sql/sem/tree: remove always-nil error return from GetBuiltinFuncDefinition

Release note: None

Author: mgartner

pkg/sql/catalog/descs/dist_sql_function_resolver.go

@@ -46,10 +46,7 @@ func (d *DistSQLFunctionResolver) ResolveFunction(
 		return nil, err
 	}
 	// Get builtin and udf functions if there is any match.
-	builtinDef, err := tree.GetBuiltinFuncDefinition(fn, path)
-	if err != nil {
-		return nil, err
-	}
+	builtinDef := tree.GetBuiltinFuncDefinition(fn, path)
 	if builtinDef == nil {
 		return nil, errors.Mark(
 			pgerror.Newf(pgcode.UndefinedFunction, "function %s not found", fn.Object()),

pkg/sql/opt/testutils/testcat/function.go

@@ -34,10 +34,7 @@ func (tc *Catalog) ResolveFunction(
 	}
 
 	// Attempt to resolve to a built-in function first.
-	def, err := tree.GetBuiltinFuncDefinition(fn, path)
-	if err != nil {
-		return nil, err
-	}
+	def := tree.GetBuiltinFuncDefinition(fn, path)
 	if def != nil {
 		return def, nil
 	}

pkg/sql/schema_resolver.go

@@ -457,10 +457,7 @@ func (sr *schemaResolver) ResolveFunction(
 	}
 
 	// Get builtin and udf functions if there is any match.
-	builtinDef, err := tree.GetBuiltinFuncDefinition(fn, path)
-	if err != nil {
-		return nil, err
-	}
+	builtinDef := tree.GetBuiltinFuncDefinition(fn, path)
 	routine, err := maybeLookupRoutine(ctx, sr, path, fn)
 	if err != nil {
 		return nil, err

pkg/sql/schemachanger/scdeps/sctestdeps/test_deps.go

@@ -1393,10 +1393,7 @@ func (s *TestState) ResolveFunction(
 	if err != nil {
 		return nil, err
 	}
-	fd, err := tree.GetBuiltinFuncDefinition(fnName, path)
-	if err != nil {
-		return nil, err
-	}
+	fd := tree.GetBuiltinFuncDefinition(fnName, path)
 	if fd != nil {
 		return fd, nil
 	}

pkg/sql/schemachanger/sctest/backup.go

@@ -691,10 +691,7 @@ func containsUDF(expr tree.Expr) (bool, error) {
 			if err != nil {
 				return false, nil, err
 			}
-			fd, err := tree.GetBuiltinFuncDefinition(fn, &sessiondata.DefaultSearchPath)
-			if err != nil {
-				return false, nil, err
-			}
+			fd := tree.GetBuiltinFuncDefinition(fn, &sessiondata.DefaultSearchPath)
 			if fd == nil {
 				foundUDF = true
 			}

pkg/sql/sem/tree/function_definition.go

@@ -599,10 +599,7 @@ func QualifyBuiltinFunctionDefinition(
 func GetBuiltinFuncDefinitionOrFail(
 	fName RoutineName, searchPath SearchPath,
 ) (*ResolvedFunctionDefinition, error) {
-	def, err := GetBuiltinFuncDefinition(fName, searchPath)
-	if err != nil {
-		return nil, err
-	}
+	def := GetBuiltinFuncDefinition(fName, searchPath)
 	if def == nil {
 		forError := fName // prevent fName from escaping
 		return nil, errors.Mark(
@@ -634,28 +631,23 @@ func GetBuiltinFunctionByOIDOrFail(oid oid.Oid) (*ResolvedFunctionDefinition, er
 // in the specific schema are searched. Otherwise, all schemas on the given
 // searchPath are searched. A nil is returned if no function is found. It's
 // caller's choice to error out if function not found.
-//
-// In theory, this function returns an error only when the search path iterator
-// errors which won't happen since the iterating function never errors out. But
-// error is still checked and return from the function signature just in case
-// we change the iterating function in the future.
 func GetBuiltinFuncDefinition(
 	fName RoutineName, searchPath SearchPath,
-) (*ResolvedFunctionDefinition, error) {
+) *ResolvedFunctionDefinition {
 	if fName.ExplicitSchema {
-		return ResolvedBuiltinFuncDefs[fName.Schema()+"."+fName.Object()], nil
+		return ResolvedBuiltinFuncDefs[fName.Schema()+"."+fName.Object()]
 	}
 
 	// First try that if we can get function directly with the function name.
 	// There is a case where the part[0] of the name is a qualified string when
-	// the qualified name is double quoted as a single name like "schema.fn".
+	// the qualified name is double-quoted as a single name like "schema.fn".
 	if def, ok := ResolvedBuiltinFuncDefs[fName.Object()]; ok {
-		return def, nil
+		return def
 	}
 
 	// Then try if it's in pg_catalog.
 	if def, ok := ResolvedBuiltinFuncDefs[catconstants.PgCatalogName+"."+fName.Object()]; ok {
-		return def, nil
+		return def
 	}
 
 	// If not in pg_catalog, go through search path.
@@ -669,5 +661,5 @@ func GetBuiltinFuncDefinition(
 		}
 	}
 
-	return resolvedDef, nil
+	return resolvedDef
 }

pkg/sql/sem/tree/function_definition_test.go

@@ -71,8 +71,7 @@ func TestBuiltinFunctionResolver(t *testing.T) {
 		t.Run(tc.testName, func(t *testing.T) {
 			fnName, err := tc.fnName.ToRoutineName()
 			require.NoError(t, err)
-			funcDef, err := tree.GetBuiltinFuncDefinition(fnName, &path)
-			require.NoError(t, err)
+			funcDef := tree.GetBuiltinFuncDefinition(fnName, &path)
 			if tc.expectNoFound {
 				require.Nil(t, funcDef)
 				return