Determine filename of Interface declaration

[ProphetLamb]

My goal is to determine the filename of an interface declaration. For most classes this is trivial using the SequencePoint of any method body.

This discussion is related #831

Interfaces cannot have a method body, and thus no SequencePoint we can use to determine the filename. Is it possible to find the files an interface is declared in any other way?

This is the working implementation for any typedef with a methodbody, that I am using:

using Mono.Cecil;
using Mono.Cecil.Cil;
using Mono.Cecil.Pdb;

IEnumerable<TypeFile> GetTypesFiles(string dir, string dllFile, string pdbFile) {
    DefaultAssemblyResolver asmResolver = new();
    asmResolver.AddSearchDirectory(dir);
    
    ReaderParameters parameters = new() { ReadSymbols = true};
    ModuleDefinition mod = ModuleDefinition.ReadModule(dllFile, parameters);
    
    PdbReaderProvider pdbReader = new();
    ISymbolReader symbols = pdbReader.GetSymbolReader(mod, pdbFile);
    foreach (TypeDefinition type in mod.GetTypes()) {
        if (!type.HasMethods) {
            continue;
        }

        foreach (string file in type.Methods
           .Select(method => symbols.Read(method))
           .Select(symbol => symbol.SequencePoints
               .Where(static (SequencePoint seq) => seq is not null)
               .Select(static (SequencePoint seq) => seq.Document.Url)
               .Distinct()) // partial classes span multiple documents
           .SelectMany(seqs => seqs)
           .Where(seq => seq is not null)) {
            yield return new(type, file);
        }
    }
}

string SourceAssemblyFolder = "publish";
string SourceAssemblyFileName = "publish/test.dll";
string SourceSymbolsFileName = "publish/test.pdb";


var defs = GetTypesFiles(SourceAssemblyFolder, SourceAssemblyFileName, SourceSymbolsFileName).ToArray();
foreach (var def in defs) {
    Console.WriteLine(def.ToString());
}

record struct TypeFile(TypeDefinition type, string filepath);

If the test assembly exclusively contains abstract classes without method bodies or interfaces, as expected, nothing is output.

interface ITest {
    string Name { get; set }
    string Surname { get; set; }
    string FullName();
}
abstract class Test : ITest {
    abstract string Name { get; set }
    abstract string Surname { get; set; }
    abstract string FullName();
}

[ProphetLamb]

I solved it using the regular MetadataReader. In the hope that it will help someone after me, I published two tools that extract the data I require.

• https://github.com/ProphetLamb/SourceLinkExtract
• https://github.com/ProphetLamb/SourceSymbolMapper

dotnet tool install --global SourceLinkExtract
dotnet tool install --global SourceSymbolMapper

extract test.pdb meta.json out
mapper meta.json out symbols.json