internal changes to plugin

PiperOrigin-RevId: 635990609

src/google/protobuf/compiler/command_line_interface.cc

@@ -1851,14 +1851,25 @@ CommandLineInterface::ParseArgumentStatus CommandLineInterface::ParseArguments(
     bool foundImplicitPlugin = false;
     for (const auto& d : output_directives_) {
       if (d.generator == nullptr) {
+        // Infers the plugin name from the plugin_prefix_ and output directive.
         std::string plugin_name = PluginName(plugin_prefix_, d.name);
+
+        // Since plugin_parameters_ is also inferred from --xxx_opt, we check
+        // that it actually matches the plugin name inferred from --xxx_out.
         if (plugin_name == kv.first) {
           foundImplicitPlugin = true;
           break;
         }
       }
     }
-    if (!foundImplicitPlugin) {
+
+    // This is a special case for cc_plugin invocations that are only with
+    // "--cpp_opt" but no "--cpp_out". In this case, "--cpp_opt" only serves
+    // as passing the arguments to cc_plugins, and no C++ generator is required
+    // to be present in the invocation. We didn't have to skip for C++ generator
+    // previously because the C++ generator was built-in.
+    if (!foundImplicitPlugin &&
+        kv.first != absl::StrCat(plugin_prefix_, "gen-cpp")) {
       std::cerr << "Unknown flag: "
                 // strip prefix + "gen-" and add back "_opt"
                 << "--" << kv.first.substr(plugin_prefix_.size() + 4) << "_opt"
@@ -2781,6 +2792,9 @@ bool CommandLineInterface::GeneratePluginOutput(
   const DescriptorPool* pool = parsed_files[0]->pool();
   absl::flat_hash_set<std::string> files_to_generate(input_files_.begin(),
                                                      input_files_.end());
+  static const auto builtin_plugins = new absl::flat_hash_set<std::string>(
+      {"protoc-gen-cpp", "protoc-gen-java", "protoc-gen-mutable_java",
+       "protoc-gen-python"});
   for (FileDescriptorProto& file_proto : *request.mutable_proto_file()) {
     if (files_to_generate.contains(file_proto.name())) {
       const FileDescriptor* file = pool->FindFileByName(file_proto.name());
@@ -2789,7 +2803,11 @@ bool CommandLineInterface::GeneratePluginOutput(
       // Don't populate source code info or json_name for bootstrap protos.
       if (!bootstrap) {
         file->CopySourceCodeInfoTo(&file_proto);
-        file->CopyJsonNameTo(&file_proto);
+
+        // The built-in code generators didn't use the json names.
+        if (!builtin_plugins->contains(plugin_name)) {
+          file->CopyJsonNameTo(&file_proto);
+        }
       }
       StripSourceRetentionOptions(*file->pool(), file_proto);
     }

src/google/protobuf/compiler/command_line_interface.h

@@ -366,7 +366,8 @@ class PROTOC_EXPORT CommandLineInterface {
   //   protoc --foo_out=outputdir --foo_opt=enable_bar ...
   // Then there will be an entry ("--foo_out", "enable_bar") in this map.
   absl::flat_hash_map<std::string, std::string> generator_parameters_;
-  // Similar to generator_parameters_, but stores the parameters for plugins.
+  // Similar to generator_parameters_, stores the parameters for plugins but the
+  // key is the actual plugin name e.g. "protoc-gen-foo".
   absl::flat_hash_map<std::string, std::string> plugin_parameters_;
 
   // See AllowPlugins().  If this is empty, plugins aren't allowed.

src/google/protobuf/compiler/command_line_interface_unittest.cc

@@ -131,7 +131,9 @@ std::string CreatePluginArg() {
 
 class CommandLineInterfaceTest : public CommandLineInterfaceTester {
  protected:
-  CommandLineInterfaceTest();
+  CommandLineInterfaceTest() = default;
+
+  void SetUp() override;
 
   // Runs the CommandLineInterface with the given command line.  The
   // command is automatically split on spaces, and the string "$tmpdir"
@@ -235,9 +237,14 @@ class CommandLineInterfaceTest::NullCodeGenerator : public CodeGenerator {
   }
 };
 
+class ProtocMinimalCLITest : public CommandLineInterfaceTest {
+ protected:
+  void SetUp() override {}
+};
+
 // ===================================================================
 
-CommandLineInterfaceTest::CommandLineInterfaceTest() {
+void CommandLineInterfaceTest::SetUp() {
   // Reset the mock generator's test case environment variable.
   SetMockGeneratorTestCase("");