Suggestion for extending the WholeProjectDecompiler API

[aldelaro5]

Is your feature request related to a problem? Please describe.

I would like to be able to use the WholeProjectDecompiler in a way that doesn't seem supported with the current API without some intrusive measures. Specifically, I would like to be able to output the C# code, but in a manner that is similar to what I would get if I were to have the C# code with its associated IL commented out next to it on each lines.

The GUI frontend has the option to have IL with C# which is close, but it's not possible to export it in such a way that I have a csproj with many .cs files that are outputed this way. In other words, I HAVE to use the UI to have this view which isn't suitable for my needs, I am more looking an an actual project export with the IL commented out.

The problem is while this could be technically possible (I can compare the sequence point of a ReflectionDisassembler vs a CSharpDecompiler), the current api are too restrictive for me to be able to do this easily. Sepcifically, while I can inherit from WholeProjectDecompiler, it doesn't allow me to override what happens when it tries to write to a file. The API are done in such a way that I cannot have any logic there: I have to let it decompile all .cs files with its own internal logic. It's also not possible to insert the commented IL after the fact because I would need to have the sequence points of each lines, but because I cannot have logic when it writes the code, I cannot know this informations.

Essentially, the current API is too restrictive to do this.

Describe the solution you'd like

Something more modular regarding how the files are decompiled. A couple ideas that comes in my mind (but I am open for discussions):

• Something where I can customise what happens in the ProcessFiles local method:

  ILSpy/ICSharpCode.Decompiler/CSharp/ProjectDecompiler/WholeProjectDecompiler.cs

  Line 267 in d777148

  void ProcessFiles(List<IGrouping<string, TypeDefinitionHandle>> files)

• This might be overkill, but the same could also be said for the WriteCodeFilesInProject which is currently private:

  ILSpy/ICSharpCode.Decompiler/CSharp/ProjectDecompiler/WholeProjectDecompiler.cs

  Line 215 in d777148

  IEnumerable<ProjectItemInfo> WriteCodeFilesInProject(MetadataFile module, IList<PartialTypeInfo> partialTypes, CancellationToken cancellationToken)

• I am unsure how successful I would be on this one, but it might be possible if I could override what syntax tree visitor is used here instead of CSharpOutputVisitor:

  ILSpy/ICSharpCode.Decompiler/CSharp/ProjectDecompiler/WholeProjectDecompiler.cs

  Line 309 in d777148

  syntaxTree.AcceptVisitor(new CSharpOutputVisitor(w, Settings.CSharpFormattingOptions));

Additional context

I am relatively open for discussions on this. Even if my implementation may involve duplicating SOME code of the library, my goal is I wouldn't have to duplicate everything or to intrusively modify it to do what I want and I could see other usecases for this where one might want to add comments over lines of interests, but for me specifically, I am looking to add the IL as comments. Currently, the GUI application only allows me to export all the code in one file which isn't practical if I could leverage the project exporter feature.

My one requirement is it should be possible to do with the nuget package as I find it the most modular way to use ILSpy which I need for other reasons.