Fix outer classname for javamicro/javanano.

- File class name is defined as the java_outer_classname option value
  or the file name ToCamelCase; never the single message's ClassName.
- File-scope enums are translated to constants in the file class,
  regardless of java_multiple_files.
- If java_multiple_files=true, and file's class name equals a message's
  class name, no error. This is done by detecting that the outer class
  is not needed and skipping the outer class codegen and clash checks.
  Note: there is a disparity between java[lite] and the previous
  java{micr|nan}o: when generating code for a single-message proto, the
  outer class is omitted by java{micr|nan}o if the file does not have
  java_outer_classname. This change makes java{micr|nan}o align with
  java[lite] codegen and create the outer class, but will print some
  info to warn of potential change of code.
- Also fixed the "is_own_file" detection and made all parseX() methods
  static. Previously, all messages in a java_multiple_files=true file
  are (incorrectly) considered to be in their own files, including
  nested messages, causing them to become inner classes (instance-
  bound) and forcing the parseX() methods to lose the static modifier.
- This change supersedes c/60164 and c/60086, which causes javanano to
  put enum values into enum shell classes if java_multiple_files=true.
  We now always use the parent class to host the enum values. A future
  change will add a command line option to provide more flexibility.
- Elaborated in java/README.txt.

Change-Id: I684932f90e0a028ef37c662b221def5ffa202439

1 files changed, 12 insertions, 10 deletions

diff --git a/src/google/protobuf/compiler/javanano/javanano_generator.cc b/src/google/protobuf/compiler/javanano/javanano_generator.cc
index 76e7263d..5bed1b19 100644
--- a/src/google/protobuf/compiler/javanano/javanano_generator.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_generator.cc
@@ -138,16 +138,18 @@ bool JavaNanoGenerator::Generate(const FileDescriptor* file,
 
   vector<string> all_files;
 
-  string java_filename = package_dir;
-  java_filename += file_generator.classname();
-  java_filename += ".java";
-  all_files.push_back(java_filename);
-
-  // Generate main java file.
-  scoped_ptr<io::ZeroCopyOutputStream> output(
-    output_directory->Open(java_filename));
-  io::Printer printer(output.get(), '$');
-  file_generator.Generate(&printer);
+  if (IsOuterClassNeeded(params, file)) {
+    string java_filename = package_dir;
+    java_filename += file_generator.classname();
+    java_filename += ".java";
+    all_files.push_back(java_filename);
+
+    // Generate main java file.
+    scoped_ptr<io::ZeroCopyOutputStream> output(
+      output_directory->Open(java_filename));
+    io::Printer printer(output.get(), '$');
+    file_generator.Generate(&printer);
+  }
 
   // Generate sibling files.
   file_generator.GenerateSiblings(package_dir, output_directory, &all_files);