google · copybara-service · May 27, 2025
diff --git a/bazel/protogen.bzl b/bazel/protogen.bzl
@@ -75,6 +75,7 @@ def gen_fhir_protos(
         package_deps = [],
         additional_proto_imports = [],
         disable_test = False,
+        edition = "",
         golden_java_proto_rules = []):
     """Generates a proto file from a fhir_package
 
@@ -119,6 +120,9 @@ def gen_fhir_protos(
 
     flags.append("--directory_in_source " + src_dir)
 
+    if edition != "":
+        flags.append("--edition " + edition)
+
     all_fhir_pkgs = package_deps + [
         package,
         R4_PACKAGE_DEP,
@@ -178,6 +182,7 @@ def gen_fhir_definitions_and_protos(
         additional_proto_imports = [],
         disable_test = False,
         golden_java_proto_rules = [],
+        edition = "",
         package_json = None):
     """Generates structure definitions and protos based on Extensions and Profiles protos.
 
@@ -285,6 +290,7 @@ def gen_fhir_definitions_and_protos(
         additional_proto_imports = additional_proto_imports,
         disable_test = disable_test,
         golden_java_proto_rules = golden_java_proto_rules,
+        edition = edition,
     )
 
 def _get_zip_for_pkg(pkg):

diff --git a/java/com/google/fhir/protogen/ProtoFilePrinter.java b/java/com/google/fhir/protogen/ProtoFilePrinter.java
@@ -29,6 +29,7 @@
 import com.google.fhir.proto.ProtoGeneratorAnnotations;
 import com.google.fhir.proto.ProtogenConfig;
 import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import com.google.protobuf.DescriptorProtos.Edition;
 import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
 import com.google.protobuf.DescriptorProtos.EnumOptions;
 import com.google.protobuf.DescriptorProtos.EnumValueDescriptorProto;
@@ -50,12 +51,6 @@
 /** A utility to turn protocol message descriptors into .proto files. */
 public class ProtoFilePrinter {
 
-  /** Enum represting the proto Syntax */
-  public static enum Syntax {
-    PROTO2,
-    PROTO3
-  };
-
   private static final String APACHE_LICENSE =
       "//    Copyright %1$s Google Inc.\n"
           + "//\n"
@@ -77,8 +72,6 @@ public static enum Syntax {
   private final PackageInfo.License license;
   private final String licenseDate;
 
-  private final Syntax syntax;
-
   // All Message options in this list will appear in this order, before any options not in this
   // list.  The remainder will be alphabetized.
   // This list exists largely to maintain backwards compatibility in ordering.
@@ -105,27 +98,19 @@ public static enum Syntax {
 
   /** Creates a ProtoFilePrinter with default parameters. */
   public ProtoFilePrinter(PackageInfo packageInfo) {
-    this(packageInfo, Syntax.PROTO3);
-  }
-
-  /** Creates a ProtoFilePrinter with default parameters. */
-  public ProtoFilePrinter(PackageInfo packageInfo, Syntax syntax) {
     license = packageInfo.getLicense();
     licenseDate = packageInfo.getLicenseDate();
-    this.syntax = syntax;
   }
 
   /** Creates a ProtoFilePrinter with default parameters. */
   public ProtoFilePrinter(ProtogenConfig protogenConfig) {
     license = PackageInfo.License.APACHE;
     licenseDate = protogenConfig.getLicenseDate();
-    this.syntax = Syntax.PROTO3;
   }
 
   public ProtoFilePrinter(String licenseDate) {
     license = PackageInfo.License.APACHE;
     this.licenseDate = licenseDate;
-    this.syntax = Syntax.PROTO3;
   }
 
   /** Generate a .proto file corresponding to the provided FileDescriptorProto. */
@@ -151,7 +136,15 @@ public String print(FileDescriptorProto fileDescriptor) {
   private String printHeader(FileDescriptorProto fileDescriptor) {
     StringBuilder header = new StringBuilder();
     if (fileDescriptor.hasSyntax()) {
-      header.append("syntax = \"").append(fileDescriptor.getSyntax()).append("\";\n\n");
+      if (fileDescriptor.getSyntax().equals("editions")) {
+        if (fileDescriptor.getEdition().equals(Edition.EDITION_2023)) {
+          header.append("edition = \"2023\";\n\n");
+        } else {
+          header.append("edition = \"unknown\";\n\n");
+        }
+      } else {
+        header.append("syntax = \"").append(fileDescriptor.getSyntax()).append("\";\n\n");
+      }
     }
     if (fileDescriptor.hasPackage()) {
       header.append("package ").append(fileDescriptor.getPackage()).append(";\n");
@@ -170,6 +163,9 @@ private String printImports(FileDescriptorProto fileDescriptor) {
   private String printOptions(FileDescriptorProto fileDescriptor, String packageName) {
     StringBuilder options = new StringBuilder();
     FileOptions fileOptions = fileDescriptor.getOptions();
+    if (fileDescriptor.getSyntax().equals("editions")) {
+      options.append("option features.field_presence = IMPLICIT;\n");
+    }
     if (fileOptions.hasJavaMultipleFiles()) {
       options
           .append("option java_multiple_files = ")
@@ -279,7 +275,7 @@ private String printMessage(DescriptorProto descriptor, String typePrefix, Strin
                 descriptor, field, typePrefix, packageName, printedNestedTypeDefinitions));
         message.append(
             printField(
-                fieldBuilder.build(), fullName, fieldIndent, packageName, /* inOneof= */ false));
+                fieldBuilder.build(), fullName, fieldIndent, packageName));
         if (i != descriptor.getFieldCount() - 1) {
           message.append("\n");
         }
@@ -327,7 +323,7 @@ private String printMessage(DescriptorProto descriptor, String typePrefix, Strin
           }
           message.append(
               printField(
-                  fieldBuilder.build(), fullName, oneofIndent, packageName, /* inOneof= */ true));
+                  fieldBuilder.build(), fullName, oneofIndent, packageName));
           // If this oneof field had a description, and is not the last field, add a newline after.
           if (field.getOptions().hasExtension(ProtoGeneratorAnnotations.fieldDescription)
               && i != descriptor.getFieldCount() - 1) {
@@ -441,20 +437,14 @@ private String printField(
       FieldDescriptorProto field,
       String containingType,
       String indent,
-      String packageName,
-      boolean inOneof) {
+      String packageName) {
     StringBuilder message = new StringBuilder();
     message.append(indent);
 
-    // Add the "repeated" or "optional" keywords, if necessary.
+    // Add the "repeated" keyword, if necessary.
     if (field.getLabel() == FieldDescriptorProto.Label.LABEL_REPEATED) {
       message.append("repeated ");
     }
-    if (!inOneof
-        && field.getLabel() == FieldDescriptorProto.Label.LABEL_OPTIONAL
-        && syntax == Syntax.PROTO2) {
-      message.append("optional ");
-    }
 
     // Add the type of the field.
     if ((field.getType() == FieldDescriptorProto.Type.TYPE_MESSAGE

diff --git a/java/com/google/fhir/protogen/ProtoGenerator.java b/java/com/google/fhir/protogen/ProtoGenerator.java
@@ -59,6 +59,7 @@
 import com.google.fhir.r4.core.StructureDefinitionKindCode;
 import com.google.fhir.r4.core.TypeDerivationRuleCode;
 import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import com.google.protobuf.DescriptorProtos.Edition;
 import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
 import com.google.protobuf.DescriptorProtos.EnumValueDescriptorProto;
 import com.google.protobuf.DescriptorProtos.FieldDescriptorProto;
@@ -214,6 +215,8 @@ public class ProtoGenerator {
 
   private final ImmutableMap<String, Set<String>> coreTypeDefinitionsByFile;
 
+  private final String edition;
+
   private static Set<String> getTypesDefinedInFile(FileDescriptor file) {
     return file.getMessageTypes().stream()
         .flatMap(desc -> getTypesDefinedInType(desc).stream())
@@ -261,19 +264,21 @@ private static class StructureDefinitionData {
   public ProtoGenerator(
       PackageInfo packageInfo, String codesProtoImport, Set<FhirPackage> fhirPackages)
       throws InvalidFhirException {
-    this(packageInfo, codesProtoImport, fhirPackages, null);
+    this(packageInfo, codesProtoImport, fhirPackages, null, "");
   }
 
   public ProtoGenerator(
       PackageInfo packageInfo,
       String codesProtoImport,
       Set<FhirPackage> fhirPackages,
-      ValueSetGenerator valueSetGenerator)
+      ValueSetGenerator valueSetGenerator,
+      String edition)
       throws InvalidFhirException {
     this.packageInfo = packageInfo;
     this.codesProtoImport = codesProtoImport;
     this.fhirVersion = FhirVersion.fromAnnotation(packageInfo.getFhirVersion());
     this.valueSetGenerator = valueSetGenerator;
+    this.edition = edition;
 
     ImmutableMap.Builder<String, Set<String>> coreTypeBuilder = new ImmutableMap.Builder<>();
     for (Map.Entry<String, FileDescriptor> entry : fhirVersion.coreTypeMap.entrySet()) {
@@ -1834,7 +1839,13 @@ public FileDescriptorProto generateFileDescriptor(List<StructureDefinition> defs
   public FileDescriptorProto generateFileDescriptor(
       List<StructureDefinition> defs, List<String> additionalImports) throws InvalidFhirException {
     FileDescriptorProto.Builder builder = FileDescriptorProto.newBuilder();
-    builder.setPackage(packageInfo.getProtoPackage()).setSyntax("proto3");
+    builder.setPackage(packageInfo.getProtoPackage());
+    if (this.edition.equals("2023")) {
+      builder.setSyntax("editions");
+      builder.setEdition(Edition.EDITION_2023);
+    } else {
+      builder.setSyntax("proto3");
+    }
     FileOptions.Builder options = FileOptions.newBuilder();
     if (!packageInfo.getJavaProtoPackage().isEmpty()) {
       options.setJavaPackage(packageInfo.getJavaProtoPackage()).setJavaMultipleFiles(true);

diff --git a/java/com/google/fhir/protogen/ProtoGeneratorMain.java b/java/com/google/fhir/protogen/ProtoGeneratorMain.java
@@ -109,6 +109,11 @@ private static class Args {
                 + " will output ${output_name}_extensions.proto.")
     private String outputName = "output";
 
+    @Parameter(
+        names = {"--edition"},
+        description = "proto edition")
+    private String edition = "";
+
     @Parameter(
         names = {"--input_package"},
         description = "Input FHIR package",
@@ -160,13 +165,15 @@ void run() throws IOException, InvalidFhirException {
     // Generate the proto file.
     System.out.println("Generating proto descriptors...");
 
-    ValueSetGenerator valueSetGenerator = new ValueSetGenerator(packageInfo, fhirPackages);
+    ValueSetGenerator valueSetGenerator =
+        new ValueSetGenerator(packageInfo, fhirPackages, args.edition);
     ProtoGenerator generator =
         new ProtoGenerator(
             packageInfo,
             args.directoryInSource + "/" + args.outputName + "_codes.proto",
             fhirPackages,
-            valueSetGenerator);
+            valueSetGenerator,
+            args.edition);
     ProtoFilePrinter printer = new ProtoFilePrinter(packageInfo);
 
     try (ZipOutputStream zipOutputStream =

diff --git a/java/com/google/fhir/protogen/ValueSetGenerator.java b/java/com/google/fhir/protogen/ValueSetGenerator.java
@@ -40,6 +40,7 @@
 import com.google.fhir.r4.core.ValueSet;
 import com.google.fhir.r4.core.ValueSet.Compose.ConceptSet.Filter;
 import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import com.google.protobuf.DescriptorProtos.Edition;
 import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
 import com.google.protobuf.DescriptorProtos.EnumValueDescriptorProto;
 import com.google.protobuf.DescriptorProtos.FieldDescriptorProto;
@@ -67,9 +68,11 @@ public class ValueSetGenerator {
   private final Map<String, CodeSystem> codeSystemsByUrl;
   private final Map<String, ValueSet> valueSetsByUrl;
   private final Map<String, String> protoTypesByUrl;
+  private final String edition;
 
-  public ValueSetGenerator(PackageInfo packageInfo, Set<FhirPackage> fhirPackages) {
+  public ValueSetGenerator(PackageInfo packageInfo, Set<FhirPackage> fhirPackages, String edition) {
     this.packageInfo = packageInfo;
+    this.edition = edition;
     this.fhirVersion = FhirVersion.fromAnnotation(packageInfo.getFhirVersion());
 
     this.codeSystemsByUrl =
@@ -161,7 +164,13 @@ public FileDescriptorProto generateCodeSystemFile(FhirPackage fhirPackage) {
 
   private FileDescriptorProto generateCodeSystemFile(Collection<CodeSystem> codeSystemsToGenerate) {
     FileDescriptorProto.Builder builder = FileDescriptorProto.newBuilder();
-    builder.setPackage(packageInfo.getProtoPackage()).setSyntax("proto3");
+    builder.setPackage(packageInfo.getProtoPackage());
+    if (this.edition.equals("2023")) {
+      builder.setSyntax("editions");
+      builder.setEdition(Edition.EDITION_2023);
+    } else {
+      builder.setSyntax("proto3");
+    }
     builder.addDependency(new File(GeneratorUtils.ANNOTATION_PATH, "annotations.proto").toString());
     FileOptions.Builder options = FileOptions.newBuilder();
     if (!packageInfo.getJavaProtoPackage().isEmpty()) {

diff --git a/javatests/com/google/fhir/protogen/GeneratedProtoTest.java b/javatests/com/google/fhir/protogen/GeneratedProtoTest.java
@@ -66,6 +66,9 @@ public void testGeneratedProto() throws Exception {
     }
 
     for (String filename : generatedContentsByFilename.keySet()) {
+      if (filename.startsWith(".")) {
+        continue;
+      }
       assertThat(goldenContentsByFilename).containsKey(filename);
       assertThat(cleanProtoFile(generatedContentsByFilename.get(filename)))
           .isEqualTo(cleanProtoFile(goldenContentsByFilename.get(filename)));

diff --git a/javatests/com/google/fhir/protogen/ProtoGeneratorTest.java b/javatests/com/google/fhir/protogen/ProtoGeneratorTest.java
@@ -79,7 +79,8 @@ private static ProtoGenerator makeProtoGenerator(
         packageInfo,
         codesProtoImport,
         ImmutableSet.copyOf(packages),
-        new ValueSetGenerator(packageInfo, packages));
+        new ValueSetGenerator(packageInfo, packages, "2023"),
+        "2023");
   }
 
   public ProtoGeneratorTest() throws Exception {