Implement Edition 2024

.protoc_version

@@ -1 +1 @@
-32.0
+33.0

experimental/ast/syntax/name.go

@@ -0,0 +1,41 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// 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.
+
+package syntax
+
+import (
+	"fmt"
+	"strconv"
+)
+
+var names = func() map[Syntax]string {
+	names := make(map[Syntax]string)
+	for syntax := range All() {
+		if syntax.IsEdition() {
+			names[syntax] = fmt.Sprintf("Edition %s", syntax)
+		} else {
+			names[syntax] = strconv.Quote(syntax.String())
+		}
+	}
+	return names
+}()
+
+// Name returns the name of this syntax as it should appear in diagnostics.
+func (s Syntax) Name() string {
+	name, ok := names[s]
+	if !ok {
+		return "Edition <?>"
+	}
+	return name
+}

experimental/internal/erredition/erredition.go

@@ -0,0 +1,112 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// 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.
+
+// Package erredition defines common diagnostics for issuing errors about
+// the wrong edition being used.
+package erredition
+
+import (
+	"github.com/bufbuild/protocompile/experimental/ast"
+	"github.com/bufbuild/protocompile/experimental/ast/syntax"
+	"github.com/bufbuild/protocompile/experimental/report"
+)
+
+// TooNew diagnoses an edition that is too old for the feature used.
+type TooOld struct {
+	What    any
+	Where   report.Spanner
+	Decl    ast.DeclSyntax
+	Current syntax.Syntax
+	Intro   syntax.Syntax
+}
+
+// Diagnose implements [report.Diagnoser].
+func (e TooOld) Diagnose(d *report.Diagnostic) {
+	kind := "syntax"
+	if e.Current.IsEdition() {
+		kind = "edition"
+	}
+
+	d.Apply(
+		report.Message("`%s` is not supported in %s", e.What, e.Current.Name()),
+		report.Snippet(e.Where),
+		report.Snippetf(e.Decl.Value(), "%s specified here", kind),
+	)
+
+	if e.Intro != syntax.Unknown {
+		d.Apply(report.Helpf("`%s` requires at least %s", e.What, e.Intro.Name()))
+	}
+}
+
+// TooNew diagnoses an edition that is too new for the feature used.
+type TooNew struct {
+	Current syntax.Syntax
+	Decl    ast.DeclSyntax
+
+	Deprecated, Removed             syntax.Syntax
+	DeprecatedReason, RemovedReason string
+
+	What  any
+	Where report.Spanner
+}
+
+// Diagnose implements [report.Diagnoser].
+func (e TooNew) Diagnose(d *report.Diagnostic) {
+	kind := "syntax"
+	if e.Current.IsEdition() {
+		kind = "edition"
+	}
+
+	err := "not supported"
+	if !e.isRemoved() {
+		err = "deprecated"
+	}
+
+	d.Apply(
+		report.Message("`%s` is %s in %s", e.What, err, e.Current.Name()),
+		report.Snippet(e.Where),
+		report.Snippetf(e.Decl.Value(), "%s specified here", kind),
+	)
+
+	if e.isRemoved() {
+		if e.isDeprecated() {
+			d.Apply(report.Helpf("deprecated since %s, removed in %s", e.Deprecated.Name(), e.Removed.Name()))
+		} else {
+			d.Apply(report.Helpf("removed in %s", e.Removed.Name()))
+		}
+
+		if e.RemovedReason != "" {
+			d.Apply(report.Helpf("%s", normalizeReason(e.RemovedReason)))
+			return
+		}
+	} else if e.isDeprecated() {
+		if e.Removed != syntax.Unknown {
+			d.Apply(report.Helpf("deprecated since %s, to be removed in %s", e.Deprecated.Name(), e.Removed.Name()))
+		} else {
+			d.Apply(report.Helpf("deprecated since %s", e.Deprecated.Name()))
+		}
+	}
+
+	if e.DeprecatedReason != "" {
+		d.Apply(report.Helpf("%s", normalizeReason(e.DeprecatedReason)))
+	}
+}
+
+func (e TooNew) isDeprecated() bool {
+	return e.Deprecated != syntax.Unknown && e.Deprecated <= e.Current
+}
+
+func (e TooNew) isRemoved() bool {
+	return e.Removed != syntax.Unknown && e.Removed <= e.Current
+}

experimental/internal/erredition/normalize.go

@@ -0,0 +1,57 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// 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.
+
+package erredition
+
+import (
+	"regexp"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+var (
+	whitespacePattern = regexp.MustCompile(`[ \t\r\n]+`)
+	protoDevPattern   = regexp.MustCompile(` See http:\/\/protobuf\.dev\/[^ ]+ for more information\.?`)
+	periodPattern     = regexp.MustCompile(`\.( [A-Z]|$)`)
+	editionPattern    = regexp.MustCompile(`edition [0-9]+`)
+)
+
+// normalizeReason canonicalizes the appearance of deprecation reasons.
+// Some built-in deprecation warnings have double spaces after periods.
+func normalizeReason(text string) string {
+	// First, normalize all whitespace.
+	text = whitespacePattern.ReplaceAllString(text, " ")
+
+	// Delete protobuf.dev links; these should ideally use our specialized link
+	// formatting instead.
+	text = protoDevPattern.ReplaceAllString(text, "")
+
+	// Replace all sentence-ending periods with semicolons.
+	text = periodPattern.ReplaceAllStringFunc(text, func(match string) string {
+		if match == "." {
+			return ""
+		}
+		return ";" + strings.ToLower(match[1:])
+	})
+
+	// Capitalize "Edition" when followed by an edition number.
+	text = editionPattern.ReplaceAllStringFunc(text, func(s string) string {
+		return "E" + s[1:]
+	})
+
+	// Finally, de-capitalize the first letter.
+	r, n := utf8.DecodeRuneInString(text)
+	return string(unicode.ToLower(r)) + text[n:]
+}

experimental/internal/erredition/normalize_test.go

@@ -0,0 +1,30 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// 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.
+
+package erredition
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNormalize(t *testing.T) {
+	t.Parallel()
+
+	assert.Equal(t,
+		"the legacy closed enum behavior in Java is deprecated and is scheduled to be removed in Edition 2025",
+		normalizeReason("The legacy closed enum behavior in Java is deprecated and is scheduled to be removed in edition 2025.  See http://protobuf.dev/programming-guides/enum/#java for more information."),
+	)
+}

experimental/ir/builtins.go

@@ -17,6 +17,7 @@ package ir
 import (
 	"fmt"
 	"reflect"
+	"strings"
 
 	"github.com/bufbuild/protocompile/experimental/id"
 	"github.com/bufbuild/protocompile/internal/arena"
@@ -77,14 +78,15 @@ type builtins struct {
 	EditionSupportWarning    Member
 	EditionSupportRemoved    Member
 
-	FeatureSet      Type
-	FeaturePresence Member
-	FeatureEnumType Member
-	FeaturePacked   Member
-	FeatureUTF8     Member
-	FeatureGroup    Member
-	FeatureEnum     Member
-	FeatureJSON     Member
+	FeatureSet        Type
+	FeaturePresence   Member
+	FeatureEnumType   Member
+	FeaturePacked     Member
+	FeatureUTF8       Member
+	FeatureGroup      Member
+	FeatureEnum       Member
+	FeatureJSON       Member
+	FeatureVisibility Member `builtin:"optional"`
 
 	FileFeatures      Member
 	MessageFeatures   Member
@@ -162,14 +164,15 @@ type builtinIDs struct {
 	EditionSupportWarning    intern.ID `intern:"google.protobuf.FieldOptions.FeatureSupport.deprecation_warning"`
 	EditionSupportRemoved    intern.ID `intern:"google.protobuf.FieldOptions.FeatureSupport.edition_removed"`
 
-	FeatureSet      intern.ID `intern:"google.protobuf.FeatureSet"`
-	FeaturePresence intern.ID `intern:"google.protobuf.FeatureSet.field_presence"`
-	FeatureEnumType intern.ID `intern:"google.protobuf.FeatureSet.enum_type"`
-	FeaturePacked   intern.ID `intern:"google.protobuf.FeatureSet.repeated_field_encoding"`
-	FeatureUTF8     intern.ID `intern:"google.protobuf.FeatureSet.utf8_validation"`
-	FeatureGroup    intern.ID `intern:"google.protobuf.FeatureSet.message_encoding"`
-	FeatureEnum     intern.ID `intern:"google.protobuf.FeatureSet.enum_type"`
-	FeatureJSON     intern.ID `intern:"google.protobuf.FeatureSet.json_format"`
+	FeatureSet        intern.ID `intern:"google.protobuf.FeatureSet"`
+	FeaturePresence   intern.ID `intern:"google.protobuf.FeatureSet.field_presence"`
+	FeatureEnumType   intern.ID `intern:"google.protobuf.FeatureSet.enum_type"`
+	FeaturePacked     intern.ID `intern:"google.protobuf.FeatureSet.repeated_field_encoding"`
+	FeatureUTF8       intern.ID `intern:"google.protobuf.FeatureSet.utf8_validation"`
+	FeatureGroup      intern.ID `intern:"google.protobuf.FeatureSet.message_encoding"`
+	FeatureEnum       intern.ID `intern:"google.protobuf.FeatureSet.enum_type"`
+	FeatureJSON       intern.ID `intern:"google.protobuf.FeatureSet.json_format"`
+	FeatureVisibility intern.ID `intern:"google.protobuf.FeatureSet.default_symbol_visibility"`
 
 	FileFeatures      intern.ID `intern:"google.protobuf.FileOptions.features"`
 	MessageFeatures   intern.ID `intern:"google.protobuf.MessageOptions.features"`
@@ -207,11 +210,23 @@ func resolveBuiltins(file *File) {
 	ids := reflect.ValueOf(file.session.builtins)
 	for i := range v.NumField() {
 		field := v.Field(i)
-		id := ids.FieldByName(v.Type().Field(i).Name).Interface().(intern.ID) //nolint:errcheck
+		tyField := v.Type().Field(i)
+		id := ids.FieldByName(tyField.Name).Interface().(intern.ID) //nolint:errcheck
 		kind := kinds[field.Type()]
 
+		var optional bool
+		for option := range strings.SplitSeq(tyField.Tag.Get("builtin"), ",") {
+			if option == "optional" {
+				optional = true
+			}
+		}
+
 		ref := file.exported.lookup(file, id)
 		sym := GetRef(file, ref)
+		if sym.IsZero() && optional {
+			continue
+		}
+
 		if sym.Kind() != kind.kind {
 			panic(fmt.Errorf(
 				"missing descriptor.proto symbol: %s `%s`; got kind %s",

experimental/ir/fdp.go

@@ -141,12 +141,16 @@ func (dg *descGenerator) file(file *File, fdp *descriptorpb.FileDescriptorProto)
 		return imp.Decl.KeywordToken().Span().Start
 	}))
 	for i, imp := range imports {
-		fdp.Dependency = append(fdp.Dependency, imp.Path())
-		if imp.Public {
-			fdp.PublicDependency = append(fdp.PublicDependency, int32(i))
-		}
-		if imp.Weak {
-			fdp.WeakDependency = append(fdp.WeakDependency, int32(i))
+		if !imp.Option {
+			fdp.Dependency = append(fdp.Dependency, imp.Path())
+			if imp.Public {
+				fdp.PublicDependency = append(fdp.PublicDependency, int32(i))
+			}
+			if imp.Weak {
+				fdp.WeakDependency = append(fdp.WeakDependency, int32(i))
+			}
+		} else if imp.Option {
+			fdp.OptionDependency = append(fdp.OptionDependency, imp.Path())
 		}
 
 		if dg.sourceCodeInfoExtn != nil && !imp.Used {
@@ -274,6 +278,15 @@ func (dg *descGenerator) message(ty Type, mdp *descriptorpb.DescriptorProto) {
 		mdp.Options = new(descriptorpb.MessageOptions)
 		dg.options(options, mdp.Options)
 	}
+
+	switch exported, explicit := ty.IsExported(); {
+	case !explicit:
+		break
+	case exported:
+		mdp.Visibility = descriptorpb.SymbolVisibility_VISIBILITY_EXPORT.Enum()
+	case !exported:
+		mdp.Visibility = descriptorpb.SymbolVisibility_VISIBILITY_LOCAL.Enum()
+	}
 }
 
 var predeclaredToFDPType = []descriptorpb.FieldDescriptorProto_Type{
@@ -402,6 +415,15 @@ func (dg *descGenerator) enum(ty Type, edp *descriptorpb.EnumDescriptorProto) {
 		edp.Options = new(descriptorpb.EnumOptions)
 		dg.options(options, edp.Options)
 	}
+
+	switch exported, explicit := ty.IsExported(); {
+	case !explicit:
+		break
+	case exported:
+		edp.Visibility = descriptorpb.SymbolVisibility_VISIBILITY_EXPORT.Enum()
+	case !exported:
+		edp.Visibility = descriptorpb.SymbolVisibility_VISIBILITY_LOCAL.Enum()
+	}
 }
 
 func (dg *descGenerator) enumValue(f Member, evdp *descriptorpb.EnumValueDescriptorProto) {