Fix a bug where message-level extension identifier should also be generated in the source file.

PiperOrigin-RevId: 513687688

protos/BUILD

@@ -41,7 +41,6 @@ cc_library(
     copts = UPB_DEFAULT_CPPOPTS,
     visibility = ["//visibility:public"],
     deps = [
-        "//:message_accessors",
         "//:mini_table",
         "//:upb",
         "@com_google_absl//absl/status",

protos/protos.h

@@ -29,6 +29,7 @@
 #define UPB_PROTOS_PROTOS_H_
 
 #include <type_traits>
+#include <vector>
 
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
@@ -159,7 +160,8 @@ typename T::CProxy CreateMessage(upb_Message* msg) {
 
 class ExtensionMiniTableProvider {
  public:
-  ExtensionMiniTableProvider(const upb_MiniTableExtension* mini_table_ext)
+  constexpr explicit ExtensionMiniTableProvider(
+      const upb_MiniTableExtension* mini_table_ext)
       : mini_table_ext_(mini_table_ext) {}
   const upb_MiniTableExtension* mini_table_ext() const {
     return mini_table_ext_;
@@ -183,7 +185,8 @@ class ExtensionIdentifier : public ExtensionMiniTableProvider {
   using Extension = ExtensionType;
   using Extendee = ExtendeeType;
 
-  ExtensionIdentifier(const upb_MiniTableExtension* mini_table_ext)
+  constexpr explicit ExtensionIdentifier(
+      const upb_MiniTableExtension* mini_table_ext)
       : ExtensionMiniTableProvider(mini_table_ext) {}
 };
 
@@ -219,7 +222,7 @@ absl::StatusOr<absl::string_view> Serialize(const upb_Message* message,
 class ExtensionRegistry {
  public:
   ExtensionRegistry(
-      const std::vector<const ::protos::internal::ExtensionMiniTableProvider*>
+      const std::vector<const ::protos::internal::ExtensionMiniTableProvider*>&
           extensions,
       const upb::Arena& arena)
       : registry_(upb_ExtensionRegistry_New(arena.ptr())) {

protos_generator/BUILD

@@ -69,7 +69,6 @@ cc_library(
         "//upbc:file_layout",
         "//upbc:keywords",
         "//upbc:names",
-        "//upbc:plugin",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/log:absl_check",

protos_generator/gen_extensions.cc

@@ -53,14 +53,15 @@ void WriteExtensionIdentifierHeader(const protobuf::FieldDescriptor* ext,
   std::string mini_table_name =
       absl::StrCat(ExtensionIdentifierBase(ext), "_", ext->name(), "_ext");
   if (ext->extension_scope()) {
-    output(R"cc(
-             static ::protos::internal::ExtensionIdentifier<$0, $1> $2;
-           )cc",
-           ContainingTypeName(ext), CppTypeParameterName(ext), ext->name());
+    output(
+        R"cc(
+          static const ::protos::internal::ExtensionIdentifier<$0, $1> $2;
+        )cc",
+        ContainingTypeName(ext), CppTypeParameterName(ext), ext->name());
   } else {
     output(
         R"cc(
-          extern ::protos::internal::ExtensionIdentifier<$0, $1> $2;
+          extern const ::protos::internal::ExtensionIdentifier<$0, $1> $2;
         )cc",
         ContainingTypeName(ext), CppTypeParameterName(ext), ext->name());
   }
@@ -83,14 +84,14 @@ void WriteExtensionIdentifier(const protobuf::FieldDescriptor* ext,
   if (ext->extension_scope()) {
     output(
         R"cc(
-          ::protos::internal::ExtensionIdentifier<$0, $3> $4::$2(&$1);
+          constexpr ::protos::internal::ExtensionIdentifier<$0, $3> $4::$2(&$1);
         )cc",
         ContainingTypeName(ext), mini_table_name, ext->name(),
         CppTypeParameterName(ext), ClassName(ext->extension_scope()));
   } else {
     output(
         R"cc(
-          ::protos::internal::ExtensionIdentifier<$0, $3> $2(&$1);
+          constexpr ::protos::internal::ExtensionIdentifier<$0, $3> $2(&$1);
         )cc",
         ContainingTypeName(ext), mini_table_name, ext->name(),
         CppTypeParameterName(ext));

protos_generator/gen_messages.cc

@@ -350,6 +350,8 @@ void WriteMessageImplementation(
           }
         )cc",
         ClassName(descriptor));
+
+    WriteExtensionIdentifiersImplementation(descriptor, file_exts, output);
   }
 }
 

protos_generator/tests/test_generated.cc

@@ -598,14 +598,25 @@ TEST(CppGeneratedCode, ParseWithExtensionRegistry) {
   ThemeExtension extension1;
   extension1.set_ext_name("Hello World");
   EXPECT_EQ(true, ::protos::SetExtension(model, theme, extension1).ok());
+  EXPECT_EQ(true, ::protos::SetExtension(model, ThemeExtension::theme_extension,
+                                         extension1)
+                      .ok());
   ::upb::Arena arena;
   auto bytes = ::protos::Serialize(model, arena);
   EXPECT_EQ(true, bytes.ok());
-  ::protos::ExtensionRegistry extensions({&theme, &other_ext}, arena);
+  ::protos::ExtensionRegistry extensions(
+      {&theme, &other_ext, &ThemeExtension::theme_extension}, arena);
   TestModel parsed_model =
       ::protos::Parse<TestModel>(bytes.value(), extensions).value();
   EXPECT_EQ("Test123", parsed_model.str1());
   EXPECT_EQ(true, ::protos::GetExtension(parsed_model, theme).ok());
+  EXPECT_EQ(true, ::protos::GetExtension(parsed_model,
+                                         ThemeExtension::theme_extension)
+                      .ok());
+  EXPECT_EQ("Hello World", ::protos::GetExtension(
+                               parsed_model, ThemeExtension::theme_extension)
+                               .value()
+                               ->ext_name());
 }
 
 TEST(CppGeneratedCode, NameCollisions) {

protos_generator/tests/test_model.proto

@@ -119,6 +119,9 @@ enum PrimaryColors {
 
 // TestModel extension.
 message ThemeExtension {
+  extend TestModel {
+    optional ThemeExtension theme_extension = 12003;
+  }
   optional string ext_name = 1;
   optional bool ext_bool = 2;
 }