Implement reflection properly for fields.

- FieldAccessorTable is now non-generic
- We don't have a static field per message type in the umbrella class. (Message descriptors are accessed via the file descriptor.)
- Removed the "descriptor assigner" complication from the descriptor fixup; without extensions, we don't need it
- MapField implements IDictionary (more tests would be good...)
- RepeatedField implements IList (more tests would be good)
- Use expression trees to build accessors. (Will need to test this on various platforms... probably need a fallback strategy just using reflection directly.)
- Added FieldDescriptor.IsMap
- Added tests for reflection with generated messages

Changes to generated code coming in next commit.

1 files changed, 22 insertions, 15 deletions

diff --git a/src/google/protobuf/compiler/csharp/csharp_message.cc b/src/google/protobuf/compiler/csharp/csharp_message.cc
index 9e2fe9b6..c7a1e290 100644
--- a/src/google/protobuf/compiler/csharp/csharp_message.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_message.cc
@@ -116,8 +116,7 @@ void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
 
   // The descriptor for this type.
   printer->Print(
-      "internal static pbd::MessageDescriptor internal__$identifier$__Descriptor;\n"
-      "internal static pb::FieldAccess.FieldAccessorTable<$full_class_name$> internal__$identifier$__FieldAccessorTable;\n",
+      "internal static pb::FieldAccess.FieldAccessorTable internal__$identifier$__FieldAccessorTable;\n",
       "identifier", GetUniqueFileScopeIdentifier(descriptor_),
       "full_class_name", full_class_name());
 
@@ -130,24 +129,23 @@ void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
 void MessageGenerator::GenerateStaticVariableInitializers(io::Printer* printer) {
   map<string, string> vars;
   vars["identifier"] = GetUniqueFileScopeIdentifier(descriptor_);
-  vars["index"] = SimpleItoa(descriptor_->index());
   vars["full_class_name"] = full_class_name();
-  if (descriptor_->containing_type() != NULL) {
-    vars["parent"] = GetUniqueFileScopeIdentifier(
-	descriptor_->containing_type());
-  }
-  printer->Print(vars, "internal__$identifier$__Descriptor = ");
 
-  if (!descriptor_->containing_type()) {
-    printer->Print(vars, "Descriptor.MessageTypes[$index$];\n");
-  } else {
-    printer->Print(vars, "internal__$parent$__Descriptor.NestedTypes[$index$];\n");
+  // Work out how to get to the message descriptor (which may be multiply nested) from the file
+  // descriptor.
+  string descriptor_chain;
+  const Descriptor* current_descriptor = descriptor_;
+  while (current_descriptor->containing_type()) {
+    descriptor_chain = ".NestedTypes[" + SimpleItoa(current_descriptor->index()) + "]" + descriptor_chain;
+    current_descriptor = current_descriptor->containing_type();
   }
+  descriptor_chain = "descriptor.MessageTypes[" + SimpleItoa(current_descriptor->index()) + "]" + descriptor_chain;
+  vars["descriptor_chain"] = descriptor_chain;
 
   printer->Print(
     vars,
     "internal__$identifier$__FieldAccessorTable = \n"
-    "    new pb::FieldAccess.FieldAccessorTable<$full_class_name$>(internal__$identifier$__Descriptor,\n");
+    "    new pb::FieldAccess.FieldAccessorTable(typeof($full_class_name$), $descriptor_chain$,\n");
   printer->Print("        new string[] { ");
   for (int i = 0; i < descriptor_->field_count(); i++) {
     printer->Print("\"$property_name$\", ",
@@ -201,13 +199,22 @@ void MessageGenerator::Generate(io::Printer* printer) {
     "private static readonly uint[] _fieldTags = new uint[] { $tags$ };\n",
     "tags", JoinStrings(tags, ", "));
 
+  // Access the message descriptor via the relevant file descriptor or containing message descriptor.
+  if (!descriptor_->containing_type()) {
+    vars["descriptor_accessor"] = GetFullUmbrellaClassName(descriptor_->file())
+        + ".Descriptor.MessageTypes[" + SimpleItoa(descriptor_->index()) + "]";
+  } else {
+    vars["descriptor_accessor"] = GetClassName(descriptor_->containing_type())
+        + ".Descriptor.NestedTypes[" + SimpleItoa(descriptor_->index()) + "]";
+  }
+
   printer->Print(
     vars,
     "public static pbd::MessageDescriptor Descriptor {\n"
-    "  get { return $umbrella_class_name$.internal__$identifier$__Descriptor; }\n"
+    "  get { return $descriptor_accessor$; }\n"
     "}\n"
     "\n"
-    "public pb::FieldAccess.FieldAccessorTable<$class_name$> Fields {\n"
+    "public pb::FieldAccess.FieldAccessorTable Fields {\n"
     "  get { return $umbrella_class_name$.internal__$identifier$__FieldAccessorTable; }\n"
     "}\n"
     "\n"