Duplicate proto filenames fail build even with fileNaming=PathToUnderscores

[jeffbadorek]

When using PathToUnderscores, we are now getting an error that the generated file does not exist. However, the path to the non-existant file is the full path version (e.g. some/path/to/my.pb.swift). I believe the issue is in plugin.swift where the proto input file is mapped to an output file

            let protobufOutputPath = outputDirectory.appending(file)

            // Add the outputPath as an output file
            outputFiles.append(protobufOutputPath)

That sets up a dependency from some/path/to/my.proto to some/path/to/my.pb.swift but the latter doesn't exist since the generator actually generated some_path_to_my.pb.swift.

• MacOS 15.3
• Xcode 16.2
• Swift 6.0
• SwiftProtobuf 1.29.0

[thomasvl]

Just making sure we're following the report.

• Doesn't sound like duplicate file names at all come into play for this report? (I think you talking bout just one file?)
• And this is when using the SwiftPM Plugin support? Is that when building with SwiftPM or is it when integrated into an Xcode project?

If you could also post a small example that shows the problem it would be easier to ensure we're follow what the specific failure case you're seeing is.

[jeffbadorek]

Here's a sample project: https://github.com/jeffbadorek/SwiftProtobufPluginBug

It does produce the duplicate error and it's when I try to integrate a library that's using the protobuf plugin.

The sample project includes a local package (ProtoLib). The outer (main) project imports the local package and you get the following error when you build...

error: Filename "foo.pb.swift" used twice: '/Users/******/Library/Developer/Xcode/DerivedData/ProtoSample-fwaufpefqsshuyfliswjeqqhlzmg/SourcePackages/plugins/protolib.output/ProtoLib/SwiftProtobufPlugin/com/protobuf/common/foo.pb.swift' and '/Users/******/Library/Developer/Xcode/DerivedData/ProtoSample-fwaufpefqsshuyfliswjeqqhlzmg/SourcePackages/plugins/protolib.output/ProtoLib/SwiftProtobufPlugin/com/protobuf/uncommon/foo.pb.swift' (in target 'ProtoLib' from project 'ProtoLib')
note: Filenames are used to distinguish private declarations with the same name (in target 'ProtoLib' from project 'ProtoLib')

[thomasvl]

@FranzBusch - looks like the plugin never fully supported these modes. I'm guessing the grpc one might have the same sorta issues. Does it make sense to move some of this functionality into the plugin library so it can be shared between the protoc generators and the SwiftPM plugins?

[gjcairo]

I think this may have been solved in the gRPC plugin with this change: grpc/grpc-swift-protobuf#47 but since it has to be fixed in protobuf too it may make sense to move the logic to the plugin library

[thomasvl]

Oh interesting, so you didn't expose it in the plugin, you just forced the option to avoid the potential problem. That makes some sense for the SwiftPM plugin case. I guess removing it here would be a breaking change, but maybe still the default should switch for this reason?

[thomasvl]

I think this may have been solved in the gRPC plugin with this change: grpc/grpc-swift-protobuf#47 but since it has to be fixed in protobuf too it may make sense to move the logic to the plugin library

@gjcairo so grpc made the change and didn't consider it breaking?

[gjcairo]

Hey @thomasvl sorry, this flew under my radar.

No, we didn't consider it breaking. I may be missing something but I suppose if the default changes then it wouldn't be breaking?

[thomasvl]

@gjcairo does it make sense to move some of the enums for the generation options into the PluginLibrary (or a new one) and share them some of the support related to them for generation could also move there and be shared? Looks like the grpc plugin has some better handling for file collisions that might make sense to get moved down so it could be shared.