In Java, the dependencies you mentioned are provided by Gradle. We pull protobuf-java in here <https://github.com/thesamet/protoc-plugin-in-java/blob/d4e6da3cb7782aefa4d71dc93af7854079f1e07a/build.gradle#L15> .
In C++, the equivalent files would come from descriptor.h <https://developers.google.com/protocol-buffers/docs/reference/cpp/google.protobuf.descriptor> which is shipped with protobuf sources, and the implementation is provided by libprotobuf, which you can build yourself of the sources. The plugin is going to be an executable (.EXE on Windows) file. On Tue, Nov 27, 2018 at 9:46 PM Michael Powell <mwpowell...@gmail.com> wrote: > So... > > You've got a magic set of imports (in Java). > > import com.google.protobuf.DescriptorProtos; > import com.google.protobuf.Descriptors; > import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse; > import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest; > > Where do you get these from? > > Or Assemblies or NuGet Package References in .NET / C#, or > source/libraries, ostensibly, for C/C++. > > This is the question I have in getting started. > > The nearest assumption I could derive is that I start with protoc.exe > (Windows) and the bundled .proto files, "compile" those to target > plugin language, and build them with the project? > > Again, as a what? .DLL? .EXE? > > On Wed, Nov 28, 2018 at 12:31 AM Nadav Samet <thesa...@gmail.com> wrote: > > > > Hi Rahul and Michael, > > > > I put together a basic example of a protoc plugin in Java that generates > text files: https://github.com/thesamet/protoc-plugin-in-java > > > > The plugin itself is an executable that gets executed by protoc, it can > be written in any language. In this instance, the plugin is written in > Java, so we use gradle to generate a shell script (or bat file for windows) > that protoc will execute to run our plugin inside a JVM. The exact > instructions to run it are in the provided README.md > > > > > > On Tue, Nov 27, 2018 at 6:01 AM Michael Powell <mwpowell...@gmail.com> > wrote: > >> > >> > >> > >> On Saturday, November 10, 2018 at 5:33:11 PM UTC-5, Nadav Samet wrote: > >>> > >>> Michael, > >>> > >>> A protoc plugin is a program that receives a serialized > CodeGeneratorRequest message via its stdin, and writes a > CodeGeneratorResponse to its stdout. > >>> > >>> You asked where the CodeGeneratorRequest comes from. The answer is > that the message is defined here. Assuming your plugin is named > protoc-gen-boilerplate, then when you invoke protoc like this: > >>> protoc --boilerplate_out=outdir file1.proto [...] > >>> > >>> Then protoc would parse the proto files, prepare a > CodeGeneratorRequest and pipe it into your plugin. That request object > contains a representation of all the files you passed in the command line > as well as the files their transitively import. Your plugin should parse > the request and print out a serialized CodeGeneratorResponse. Unless you > set an error message, protoc would create the files you specified in your > response. The plugin can be written in any language, but if you use some of > the supported languages (at least C++, Python and Java, but probably > others), you'll find a method named something like DescriptorPool.BuildFile > which would convert a FileDescriptorProto to an higher-level object > (FileDescriptor) which is easier to work with. > >>> > >>> Plugins are pretty simple to write (look online for examples). I would > advise not writing a parser for proto files manually, since you'll be > chasing a moving target - over time language features get added albeit not > very often. It would also be hard to match the language spec perfectly. > >> > >> > >> I guess I am not sure quite where to begin. I've downloaded the protoc > compiler, which itself has a set of proto files, but no target language > level generated code. > >> > >> Am I accurate in assuming I run those through protoc itself to my > target language, in this case I suppose C++? > >> > >> On Windows, what form does the plugin need to take? DLL? Executable > file? > >> > >> These are the sort of nibblets I think that would make it more evident > where to pick up and run with it. > >> > >> Examples of this appear to be few and far between, if at all. > >> > >> Absent examples, I am working on a Boost Spirit Qi parser in the > meantime, which the learning curve is not a plateau, I can agree there. > It's not terrible to work through, and I end up with an AST that I know > forwards and backwards without too much extra effort once the rules have > done their synthetic magic. > >> > >> Cheers, thank you! > >> > >>> On Thursday, November 1, 2018 at 6:14:54 PM UTC-7, Michael Powell > wrote: > >>>> > >>>> Hello, > >>>> > >>>> I'm a bit confused. I thought I was grasping it earlier, then I > >>>> thought I wasn't ... What is the starting point developing a protoc > >>>> plugin? > >>>> > >>>> What I want to accomplish is processing a .proto (v2) and generating > >>>> some C# boilerplate code for it. I'm not generating a proto adapter > >>>> itself, per se, but C# DSL that would be used to support it. > >>>> > >>>> The starting point for me would seem to be receiving the compiler > >>>> request, but that itself is a .proto, which leaves me a bit confused. > >>>> Where do you obtain that from? Or are you starting by compiling those > >>>> .protos from the bits bundled with the protoc.exe compiler? > >>>> > >>>> What I want is to just have the descriptors drawn from the target > >>>> .proto(s) themselves. That's it. A full-on plugin seems like a little > >>>> bit of overkill. > >>>> > >>>> Suggestions? > >>>> > >>>> Thanks so much! > >>>> > >>>> Best regards, > >>>> > >>>> Michael Powell > >> > >> -- > >> You received this message because you are subscribed to the Google > Groups "Protocol Buffers" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an email to protobuf+unsubscr...@googlegroups.com. > >> To post to this group, send email to protobuf@googlegroups.com. > >> Visit this group at https://groups.google.com/group/protobuf. > >> For more options, visit https://groups.google.com/d/optout. > > > > > > > > -- > > -Nadav > > -- > You received this message because you are subscribed to the Google Groups > "Protocol Buffers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to protobuf+unsubscr...@googlegroups.com. > To post to this group, send email to protobuf@googlegroups.com. > Visit this group at https://groups.google.com/group/protobuf. > For more options, visit https://groups.google.com/d/optout. > -- -Nadav -- You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. 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