FindProtobuf: add flag to allow descriptor files to be generated

- The .desc files will be in the same folder as the generated .cc and .h files.
- Paths to generate .desc files are stored in a variable passed in
- This is only implemented for C++
- Remove legacy ARGS
- Add test that generates and uses C++ protobuf message
- Add test that checks that the generated .desc file can be instantiated
  with DynamicMessageFactory
- Add Help rst for new feature

1 files changed, 57 insertions, 0 deletions

diff --git a/Tests/FindProtobuf/Test/main-desc.cxx b/Tests/FindProtobuf/Test/main-desc.cxx
new file mode 100644
index 0000000..a26e562
--- /dev/null
+++ b/Tests/FindProtobuf/Test/main-desc.cxx
@@ -0,0 +1,57 @@
+#include <fstream>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/dynamic_message.h>
+#include <google/protobuf/text_format.h>
+#include <iostream>
+#include <string>
+
+int main(int argc, char* argv[])
+{
+  std::ifstream fs;
+  fs.open(argv[1], std::ifstream::in);
+  google::protobuf::FileDescriptorSet file_descriptor_set;
+  file_descriptor_set.ParseFromIstream(&fs);
+
+  const google::protobuf::DescriptorPool* compiled_pool =
+    google::protobuf::DescriptorPool::generated_pool();
+
+  if (compiled_pool == NULL) {
+    std::cerr << "compiled pool is NULL." << std::endl;
+    return 1;
+  }
+
+  google::protobuf::DescriptorPool pool(compiled_pool);
+  google::protobuf::DynamicMessageFactory dynamic_message_factory(&pool);
+
+  for (const google::protobuf::FileDescriptorProto& file_descriptor_proto :
+       file_descriptor_set.file()) {
+    const google::protobuf::FileDescriptor* file_descriptor =
+      pool.BuildFile(file_descriptor_proto);
+    if (file_descriptor == NULL) {
+      continue;
+    }
+
+    const google::protobuf::Descriptor* descriptor =
+      pool.FindMessageTypeByName("example.msgs.ExampleDesc");
+
+    if (descriptor == NULL) {
+      continue;
+    }
+
+    google::protobuf::Message* msg =
+      dynamic_message_factory.GetPrototype(descriptor)->New();
+    std::string data = "data: 1";
+    bool success = google::protobuf::TextFormat::ParseFromString(data, msg);
+
+    if (success) {
+      return 0;
+    } else {
+      std::cerr << "Failed to parse message." << std::endl;
+      return 2;
+    }
+  }
+
+  std::cerr << "No matching message found." << std::endl;
+  return 3;
+}