Make generators explicitly specify their support window for editions.

Plugins should not get automatically bumped to the latest edition until they're ready to support it.

PiperOrigin-RevId: 572638914

src/google/protobuf/compiler/code_generator.h

@@ -119,11 +119,11 @@ class PROTOC_EXPORT CodeGenerator {
 
   // Returns the minimum edition (inclusive) supported by this generator.  Any
   // proto files with an edition before this will result in an error.
-  virtual Edition GetMinimumEdition() const { return PROTOBUF_MINIMUM_EDITION; }
+  virtual Edition GetMinimumEdition() const { return Edition::EDITION_UNKNOWN; }
 
   // Returns the maximum edition (inclusive) supported by this generator.  Any
   // proto files with an edition after this will result in an error.
-  virtual Edition GetMaximumEdition() const { return PROTOBUF_MAXIMUM_EDITION; }
+  virtual Edition GetMaximumEdition() const { return Edition::EDITION_UNKNOWN; }
 
   // Builds a default feature set mapping for this generator.
   //

src/google/protobuf/compiler/cpp/generator.h

@@ -22,6 +22,7 @@
 #include "google/protobuf/compiler/code_generator.h"
 #include "absl/status/status.h"
 #include "google/protobuf/cpp_features.pb.h"
+#include "google/protobuf/descriptor.pb.h"
 
 // Must be included last.
 #include "google/protobuf/port_def.inc"
@@ -72,6 +73,9 @@ class PROTOC_EXPORT CppGenerator : public CodeGenerator {
     return FEATURE_PROTO3_OPTIONAL | FEATURE_SUPPORTS_EDITIONS;
   }
 
+  Edition GetMinimumEdition() const override { return Edition::EDITION_PROTO2; }
+  Edition GetMaximumEdition() const override { return Edition::EDITION_2023; }
+
   std::vector<const FieldDescriptor*> GetFeatureExtensions() const override {
     return {GetExtensionReflection(pb::cpp)};
   }

src/google/protobuf/compiler/mock_code_generator.cc

@@ -204,7 +204,8 @@ bool MockCodeGenerator::Generate(const FileDescriptor* file,
                                  GeneratorContext* context,
                                  std::string* error) const {
   if (FileDescriptorLegacy(file).syntax() ==
-      FileDescriptorLegacy::SYNTAX_EDITIONS) {
+          FileDescriptorLegacy::SYNTAX_EDITIONS &&
+      (suppressed_features_ & CodeGenerator::FEATURE_SUPPORTS_EDITIONS) == 0) {
     internal::VisitDescriptors(*file, [&](const auto& descriptor) {
       const FeatureSet& features = GetResolvedSourceFeatures(descriptor);
       ABSL_CHECK(features.HasExtension(pb::test))

src/google/protobuf/compiler/objectivec/generator.h

@@ -16,6 +16,7 @@
 
 #include "google/protobuf/compiler/code_generator.h"
 #include "google/protobuf/descriptor.h"
+#include "google/protobuf/descriptor.pb.h"
 
 // Must be included last
 #include "google/protobuf/port_def.inc"
@@ -48,6 +49,8 @@ class PROTOC_EXPORT ObjectiveCGenerator : public CodeGenerator {
   uint64_t GetSupportedFeatures() const override {
     return (FEATURE_PROTO3_OPTIONAL | FEATURE_SUPPORTS_EDITIONS);
   }
+  Edition GetMinimumEdition() const override { return Edition::EDITION_PROTO2; }
+  Edition GetMaximumEdition() const override { return Edition::EDITION_2023; }
 };
 
 }  // namespace objectivec

src/google/protobuf/compiler/plugin.cc

@@ -94,15 +94,18 @@ bool GenerateCode(const CodeGeneratorRequest& request,
                   CodeGeneratorResponse* response, std::string* error_msg) {
   DescriptorPool pool;
 
-  // Initialize feature set default mapping.
-  absl::StatusOr<FeatureSetDefaults> defaults =
-      generator.BuildFeatureSetDefaults();
-  if (!defaults.ok()) {
-    *error_msg = absl::StrCat("error generating feature defaults: ",
-                              defaults.status().message());
-    return false;
+  if (generator.GetSupportedFeatures() &
+      CodeGenerator::FEATURE_SUPPORTS_EDITIONS) {
+    // Initialize feature set default mapping.
+    absl::StatusOr<FeatureSetDefaults> defaults =
+        generator.BuildFeatureSetDefaults();
+    if (!defaults.ok()) {
+      *error_msg = absl::StrCat("error generating feature defaults: ",
+                                defaults.status().message());
+      return false;
+    }
+    pool.SetFeatureSetDefaults(*defaults);
   }
-  pool.SetFeatureSetDefaults(*defaults);
 
   for (int i = 0; i < request.proto_file_size(); i++) {
     const FileDescriptor* file = pool.BuildFile(request.proto_file(i));

src/google/protobuf/compiler/rust/generator.h

@@ -36,6 +36,8 @@ class PROTOC_EXPORT RustGenerator final
   uint64_t GetSupportedFeatures() const override {
     return FEATURE_PROTO3_OPTIONAL | FEATURE_SUPPORTS_EDITIONS;
   }
+  Edition GetMinimumEdition() const override { return Edition::EDITION_PROTO2; }
+  Edition GetMaximumEdition() const override { return Edition::EDITION_2023; }
 };
 
 }  // namespace rust