Support embedded fields properly

staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/embedded/doc.go

@@ -0,0 +1,47 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// +k8s:validation-gen=TypeMeta
+// +k8s:validation-gen-scheme-registry=k8s.io/code-generator/cmd/validation-gen/testscheme.Scheme
+// +k8s:validation-gen-test-fixture=validateFalse
+
+// This is a test package.
+package embedded
+
+import "k8s.io/code-generator/cmd/validation-gen/testscheme"
+
+var localSchemeBuilder = testscheme.New()
+
+type T1 struct {
+	TypeMeta int
+
+	// NOTE: It's weird to have IntField in both, but Go allows it.
+	T2  `json:",inline"`
+	*T3 `json:",inline"`
+}
+
+type T2 struct {
+	// +k8s:validateFalse="T2.IntField"
+	IntField int `json:"intField"`
+}
+
+type T3 struct {
+	// +k8s:validateFalse="T3.StringField"
+	StringField string `json:"stringField"`
+
+	// +k8s:validateFalse="T3.IntField"
+	IntField int `json:"intField"`
+}

staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/embedded/testdata/validate-false.json

@@ -0,0 +1,11 @@
+{
+  "*embedded.T1": {
+    "intField": [
+      "T2.IntField",
+      "T3.IntField"
+    ],
+    "stringField": [
+      "T3.StringField"
+    ]
+  }
+}

staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/embedded/zz_generated.validations.go

@@ -0,0 +1,101 @@
+//go:build !ignore_autogenerated
+// +build !ignore_autogenerated
+
+/*
+Copyright The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Code generated by validation-gen. DO NOT EDIT.
+
+package embedded
+
+import (
+	context "context"
+
+	operation "k8s.io/apimachinery/pkg/api/operation"
+	safe "k8s.io/apimachinery/pkg/api/safe"
+	validate "k8s.io/apimachinery/pkg/api/validate"
+	field "k8s.io/apimachinery/pkg/util/validation/field"
+	testscheme "k8s.io/code-generator/cmd/validation-gen/testscheme"
+)
+
+func init() { localSchemeBuilder.Register(RegisterValidations) }
+
+// RegisterValidations adds validation functions to the given scheme.
+// Public to allow building arbitrary schemes.
+func RegisterValidations(scheme *testscheme.Scheme) error {
+	scheme.AddValidationFunc((*T1)(nil), func(ctx context.Context, op operation.Operation, obj, oldObj interface{}) field.ErrorList {
+		return Validate_T1(ctx, op, nil /* fldPath */, obj.(*T1), safe.Cast[*T1](oldObj))
+	})
+	return nil
+}
+
+func Validate_T1(ctx context.Context, op operation.Operation, fldPath *field.Path, obj, oldObj *T1) (errs field.ErrorList) {
+	// field T1.TypeMeta has no validation
+
+	// field T1.T2
+	errs = append(errs,
+		func(fldPath *field.Path, obj, oldObj *T2) (errs field.ErrorList) {
+			errs = append(errs, Validate_T2(ctx, op, fldPath, obj, oldObj)...)
+			return
+		}(fldPath, &obj.T2, safe.Field(oldObj, func(oldObj *T1) *T2 { return &oldObj.T2 }))...)
+
+	// field T1.T3
+	errs = append(errs,
+		func(fldPath *field.Path, obj, oldObj *T3) (errs field.ErrorList) {
+			errs = append(errs, Validate_T3(ctx, op, fldPath, obj, oldObj)...)
+			return
+		}(fldPath, obj.T3, safe.Field(oldObj, func(oldObj *T1) *T3 { return oldObj.T3 }))...)
+
+	return errs
+}
+
+func Validate_T2(ctx context.Context, op operation.Operation, fldPath *field.Path, obj, oldObj *T2) (errs field.ErrorList) {
+	// field T2.IntField
+	errs = append(errs,
+		func(fldPath *field.Path, obj, oldObj *int) (errs field.ErrorList) {
+			if op.Type == operation.Update && (obj == oldObj || (obj != nil && oldObj != nil && *obj == *oldObj)) {
+				return nil // no changes
+			}
+			errs = append(errs, validate.FixedResult(ctx, op, fldPath, obj, oldObj, false, "T2.IntField")...)
+			return
+		}(fldPath.Child("intField"), &obj.IntField, safe.Field(oldObj, func(oldObj *T2) *int { return &oldObj.IntField }))...)
+
+	return errs
+}
+
+func Validate_T3(ctx context.Context, op operation.Operation, fldPath *field.Path, obj, oldObj *T3) (errs field.ErrorList) {
+	// field T3.StringField
+	errs = append(errs,
+		func(fldPath *field.Path, obj, oldObj *string) (errs field.ErrorList) {
+			if op.Type == operation.Update && (obj == oldObj || (obj != nil && oldObj != nil && *obj == *oldObj)) {
+				return nil // no changes
+			}
+			errs = append(errs, validate.FixedResult(ctx, op, fldPath, obj, oldObj, false, "T3.StringField")...)
+			return
+		}(fldPath.Child("stringField"), &obj.StringField, safe.Field(oldObj, func(oldObj *T3) *string { return &oldObj.StringField }))...)
+
+	// field T3.IntField
+	errs = append(errs,
+		func(fldPath *field.Path, obj, oldObj *int) (errs field.ErrorList) {
+			if op.Type == operation.Update && (obj == oldObj || (obj != nil && oldObj != nil && *obj == *oldObj)) {
+				return nil // no changes
+			}
+			errs = append(errs, validate.FixedResult(ctx, op, fldPath, obj, oldObj, false, "T3.IntField")...)
+			return
+		}(fldPath.Child("intField"), &obj.IntField, safe.Field(oldObj, func(oldObj *T3) *int { return &oldObj.IntField }))...)
+
+	return errs
+}

staging/src/k8s.io/code-generator/cmd/validation-gen/output_tests/embedded/zz_generated.validations_test.go

@@ -0,0 +1,30 @@
+//go:build !ignore_autogenerated
+// +build !ignore_autogenerated
+
+/*
+Copyright The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Code generated by validation-gen. DO NOT EDIT.
+
+package embedded
+
+import (
+	"testing"
+)
+
+func TestValidation(t *testing.T) {
+	localSchemeBuilder.Test(t).ValidateFixtures()
+}

staging/src/k8s.io/code-generator/cmd/validation-gen/validation.go

@@ -536,13 +536,7 @@ func (td *typeDiscoverer) discoverStruct(thisNode *typeNode, fldPath *field.Path
 	// Discover into each field of this struct.
 	for _, memb := range thisNode.valueType.Members {
 		name := memb.Name
-		if len(name) == 0 { // embedded fields
-			if memb.Type.Kind == types.Pointer {
-				name = memb.Type.Elem.Name.Name
-			} else {
-				name = memb.Type.Name.Name
-			}
-		}
+
 		// Only do exported fields.
 		if unicode.IsLower([]rune(name)[0]) {
 			continue
@@ -1041,10 +1035,6 @@ func (g *genValidations) emitValidationForChild(c *generator.Context, thisChild
 			}
 
 			if buf.Len() > 0 {
-				if len(fld.jsonName) == 0 {
-					continue // TODO: Embedded (inline) types are expected to be unnamed.
-				}
-
 				leafType, typePfx, exprPfx := getLeafTypeAndPrefixes(fld.childType)
 				targs := targs.WithArgs(generator.Args{
 					"fieldName":    fld.name,
@@ -1064,7 +1054,12 @@ func (g *genValidations) emitValidationForChild(c *generator.Context, thisChild
 					panic(fmt.Sprintf("failed to merge buffer: %v", err))
 				}
 				sw.Do("    return\n", targs)
-				sw.Do("  }(fldPath.Child(\"$.fieldJSON$\"), ", targs)
+				sw.Do("  }(", targs)
+				if len(fld.jsonName) == 0 { // embedded (inline) field
+					sw.Do("fldPath, ", targs)
+				} else {
+					sw.Do("fldPath.Child(\"$.fieldJSON$\"), ", targs)
+				}
 				sw.Do("    $.fieldExprPfx$obj.$.fieldName$, ", targs)
 				sw.Do("    $.safe.Field|raw$(oldObj, ", targs)
 				sw.Do("        func(oldObj *$.inType|raw$) $.fieldTypePfx$$.fieldType|raw$ {", targs)