Adds support for proto2 syntax for Ruby gem.

This change only adds basic proto2 support without advanced features
like extensions, custom options, maps, etc.

The protoc binary now generates ruby code for proto2 syntax.
However, for now, it is restricted to proto2 files without advanced features
like extensions, in which case it still errors out.

This change also modifies the DSL to add proto messages to the DescriptorPool.
There is a new DSL Builder#add_file to create a new FileDescriptor. With this,
the generated ruby DSL looks something like:

Google::Protobuf::DescriptorPool.generated_pool.build do
  add_file "test.proto" do
    add_message "foo" do
      optional :val, :int32, 1
    end
  end
end

1 files changed, 58 insertions, 1 deletions

diff --git a/ruby/ext/google/protobuf_c/protobuf.h b/ruby/ext/google/protobuf_c/protobuf.h
index 3e5c0520..0aa385a0 100644
--- a/ruby/ext/google/protobuf_c/protobuf.h
+++ b/ruby/ext/google/protobuf_c/protobuf.h
@@ -40,6 +40,7 @@
 // Forward decls.
 struct DescriptorPool;
 struct Descriptor;
+struct FileDescriptor;
 struct FieldDescriptor;
 struct EnumDescriptor;
 struct MessageLayout;
@@ -47,10 +48,12 @@ struct MessageField;
 struct MessageHeader;
 struct MessageBuilderContext;
 struct EnumBuilderContext;
+struct FileBuilderContext;
 struct Builder;
 
 typedef struct DescriptorPool DescriptorPool;
 typedef struct Descriptor Descriptor;
+typedef struct FileDescriptor FileDescriptor;
 typedef struct FieldDescriptor FieldDescriptor;
 typedef struct OneofDescriptor OneofDescriptor;
 typedef struct EnumDescriptor EnumDescriptor;
@@ -60,6 +63,7 @@ typedef struct MessageHeader MessageHeader;
 typedef struct MessageBuilderContext MessageBuilderContext;
 typedef struct OneofBuilderContext OneofBuilderContext;
 typedef struct EnumBuilderContext EnumBuilderContext;
+typedef struct FileBuilderContext FileBuilderContext;
 typedef struct Builder Builder;
 
 /*
@@ -118,6 +122,10 @@ struct Descriptor {
   const upb_handlers* json_serialize_handlers_preserve;
 };
 
+struct FileDescriptor {
+  const upb_filedef* filedef;
+};
+
 struct FieldDescriptor {
   const upb_fielddef* fielddef;
 };
@@ -145,18 +153,27 @@ struct EnumBuilderContext {
   VALUE enumdesc;
 };
 
+struct FileBuilderContext {
+  VALUE pending_list;
+  VALUE file_descriptor;
+  VALUE builder;
+};
+
 struct Builder {
   VALUE pending_list;
+  VALUE default_file_descriptor;
   upb_def** defs;  // used only while finalizing
 };
 
 extern VALUE cDescriptorPool;
 extern VALUE cDescriptor;
+extern VALUE cFileDescriptor;
 extern VALUE cFieldDescriptor;
 extern VALUE cEnumDescriptor;
 extern VALUE cMessageBuilderContext;
 extern VALUE cOneofBuilderContext;
 extern VALUE cEnumBuilderContext;
+extern VALUE cFileBuilderContext;
 extern VALUE cBuilder;
 
 extern VALUE cError;
@@ -175,7 +192,7 @@ VALUE DescriptorPool_alloc(VALUE klass);
 void DescriptorPool_register(VALUE module);
 DescriptorPool* ruby_to_DescriptorPool(VALUE value);
 VALUE DescriptorPool_add(VALUE _self, VALUE def);
-VALUE DescriptorPool_build(VALUE _self);
+VALUE DescriptorPool_build(int argc, VALUE* argv, VALUE _self);
 VALUE DescriptorPool_lookup(VALUE _self, VALUE name);
 VALUE DescriptorPool_generated_pool(VALUE _self);
 
@@ -184,6 +201,7 @@ void Descriptor_free(void* _self);
 VALUE Descriptor_alloc(VALUE klass);
 void Descriptor_register(VALUE module);
 Descriptor* ruby_to_Descriptor(VALUE value);
+VALUE Descriptor_initialize(VALUE _self, VALUE file_descriptor_rb);
 VALUE Descriptor_name(VALUE _self);
 VALUE Descriptor_name_set(VALUE _self, VALUE str);
 VALUE Descriptor_each(VALUE _self);
@@ -193,8 +211,19 @@ VALUE Descriptor_add_oneof(VALUE _self, VALUE obj);
 VALUE Descriptor_each_oneof(VALUE _self);
 VALUE Descriptor_lookup_oneof(VALUE _self, VALUE name);
 VALUE Descriptor_msgclass(VALUE _self);
+VALUE Descriptor_file_descriptor(VALUE _self);
 extern const rb_data_type_t _Descriptor_type;
 
+void FileDescriptor_mark(void* _self);
+void FileDescriptor_free(void* _self);
+VALUE FileDescriptor_alloc(VALUE klass);
+void FileDescriptor_register(VALUE module);
+FileDescriptor* ruby_to_FileDescriptor(VALUE value);
+VALUE FileDescriptor_initialize(int argc, VALUE* argv, VALUE _self);
+VALUE FileDescriptor_name(VALUE _self);
+VALUE FileDescriptor_syntax(VALUE _self);
+VALUE FileDescriptor_syntax_set(VALUE _self, VALUE syntax);
+
 void FieldDescriptor_mark(void* _self);
 void FieldDescriptor_free(void* _self);
 VALUE FieldDescriptor_alloc(VALUE klass);
@@ -204,6 +233,8 @@ VALUE FieldDescriptor_name(VALUE _self);
 VALUE FieldDescriptor_name_set(VALUE _self, VALUE str);
 VALUE FieldDescriptor_type(VALUE _self);
 VALUE FieldDescriptor_type_set(VALUE _self, VALUE type);
+VALUE FieldDescriptor_default(VALUE _self);
+VALUE FieldDescriptor_default_set(VALUE _self, VALUE default_value);
 VALUE FieldDescriptor_label(VALUE _self);
 VALUE FieldDescriptor_label_set(VALUE _self, VALUE label);
 VALUE FieldDescriptor_number(VALUE _self);
@@ -211,6 +242,8 @@ VALUE FieldDescriptor_number_set(VALUE _self, VALUE number);
 VALUE FieldDescriptor_submsg_name(VALUE _self);
 VALUE FieldDescriptor_submsg_name_set(VALUE _self, VALUE value);
 VALUE FieldDescriptor_subtype(VALUE _self);
+VALUE FieldDescriptor_has(VALUE _self, VALUE msg_rb);
+VALUE FieldDescriptor_clear(VALUE _self, VALUE msg_rb);
 VALUE FieldDescriptor_get(VALUE _self, VALUE msg_rb);
 VALUE FieldDescriptor_set(VALUE _self, VALUE msg_rb, VALUE value);
 upb_fieldtype_t ruby_to_fieldtype(VALUE type);
@@ -231,6 +264,8 @@ void EnumDescriptor_free(void* _self);
 VALUE EnumDescriptor_alloc(VALUE klass);
 void EnumDescriptor_register(VALUE module);
 EnumDescriptor* ruby_to_EnumDescriptor(VALUE value);
+VALUE EnumDescriptor_initialize(VALUE _self, VALUE file_descriptor_rb);
+VALUE EnumDescriptor_file_descriptor(VALUE _self);
 VALUE EnumDescriptor_name(VALUE _self);
 VALUE EnumDescriptor_name_set(VALUE _self, VALUE str);
 VALUE EnumDescriptor_add_value(VALUE _self, VALUE name, VALUE number);
@@ -272,12 +307,23 @@ EnumBuilderContext* ruby_to_EnumBuilderContext(VALUE value);
 VALUE EnumBuilderContext_initialize(VALUE _self, VALUE enumdesc);
 VALUE EnumBuilderContext_value(VALUE _self, VALUE name, VALUE number);
 
+void FileBuilderContext_mark(void* _self);
+void FileBuilderContext_free(void* _self);
+VALUE FileBuilderContext_alloc(VALUE klass);
+void FileBuilderContext_register(VALUE module);
+VALUE FileBuilderContext_initialize(VALUE _self, VALUE file_descriptor,
+				    VALUE builder);
+VALUE FileBuilderContext_add_message(VALUE _self, VALUE name);
+VALUE FileBuilderContext_add_enum(VALUE _self, VALUE name);
+VALUE FileBuilderContext_pending_descriptors(VALUE _self);
+
 void Builder_mark(void* _self);
 void Builder_free(void* _self);
 VALUE Builder_alloc(VALUE klass);
 void Builder_register(VALUE module);
 Builder* ruby_to_Builder(VALUE value);
 VALUE Builder_initialize(VALUE _self);
+VALUE Builder_add_file(int argc, VALUE *argv, VALUE _self);
 VALUE Builder_add_message(VALUE _self, VALUE name);
 VALUE Builder_add_enum(VALUE _self, VALUE name);
 VALUE Builder_finalize_to_pool(VALUE _self, VALUE pool_rb);
@@ -443,10 +489,12 @@ VALUE Map_iter_value(Map_iter* iter);
 // -----------------------------------------------------------------------------
 
 #define MESSAGE_FIELD_NO_CASE ((size_t)-1)
+#define MESSAGE_FIELD_NO_HASBIT ((size_t)-1)
 
 struct MessageField {
   size_t offset;
   size_t case_offset;  // for oneofs, a uint32. Else, MESSAGE_FIELD_NO_CASE.
+  size_t hasbit;
 };
 
 struct MessageLayout {
@@ -457,6 +505,9 @@ struct MessageLayout {
 
 MessageLayout* create_layout(const upb_msgdef* msgdef);
 void free_layout(MessageLayout* layout);
+bool field_contains_hasbit(MessageLayout* layout,
+                 const upb_fielddef* field);
+VALUE layout_get_default(const upb_fielddef* field);
 VALUE layout_get(MessageLayout* layout,
                  const void* storage,
                  const upb_fielddef* field);
@@ -464,6 +515,12 @@ void layout_set(MessageLayout* layout,
                 void* storage,
                 const upb_fielddef* field,
                 VALUE val);
+VALUE layout_has(MessageLayout* layout,
+                 const void* storage,
+                 const upb_fielddef* field);
+void layout_clear(MessageLayout* layout,
+                 const void* storage,
+                 const upb_fielddef* field);
 void layout_init(MessageLayout* layout, void* storage);
 void layout_mark(MessageLayout* layout, void* storage);
 void layout_dup(MessageLayout* layout, void* to, void* from);