Types are not generated when referenced project already defines them, even though they are inaccessible

[TIPConsulting]

VS is throwing an error during compilation because of a backend file that I cannot see. Here are the details that I can see

CS0122: 'BOOL' is inaccessible due to its protection level

File: PInvoke.User32.cs, Line 36

The method endpoint is generated properly, Pinvoke.LockWorkStation() is available and no errors appear in my app code. "LockWorkStation" is the only method in my NativeMethods.txt

[AArnott]

a backend file that I cannot see

Tip: if you're using VS 16.9 (in Preview), all generated files will be discoverable via Solution Explorer:

But that may not yet be available in the public preview. Watch for it.
In the meantime something else that may help you is to add a NativeMethods.json file to your project with this content:

{
  "$schema": "D:\\git\\CsWin32\\src\\Microsoft.Windows.CsWin32\\settings.schema.json",
  "emitSingleFile": true
}

Then when you use F12 on LockWorkStation the file you are taken to will have everything in it so you can review it (including BOOL).

Now to your actual problem... that's very peculiar because we generate BOOL when we generate the function that requires it. Can you share the content of the generated file after applying the NativeMethods.json trick?

[TIPConsulting]

The first tip that you showed about finding the generated files does work for me, thanks (but it has a bug, see footnote)

I made a new discovery that might help. The project structure is a bit bigger than I first said, and the extra complexity is key to the issue.

Project structure:
Plywood
    |__Plywood.Client

Plywood.Client references Plywood. Plywood and Plywood.Client both use CsWin32 generators. I have added the NativeMethods.json modifier to both projects

Right now, if both projects have populated NativeMethods.txt files, then Plywood will compile but Plywood.Client will fail. If I remove the NativeMethod.txt from Plywood, then Plywood.Client will compile. So this BOOL error is happening when there is a parent project that also uses CsWin32

Here is the NativeMethods.cs file from Plywood.Client if both generators are enabled:
Plywood.Client.NativeMethods_Broken.txt

Here is the Here is the NativeMethods.cs file from Plywood.Client if the parent generator is disabled:
Plywood.Client.NativeMethods.txt

When the parent generator is active, the child does not generate its own BOOL. This is likely because BOOL is already generated by the parent, but its marked as internal so the child cant access it. Maybe the generators run in a shared context even though they target different projects? Or possibly related to work done for #3?

---

Now for a bonus bug: This is related to viewing the generator output code in VS. In the screenshot, I show two projects with generated NativeMethods.cs files. Both of those file icons open the same physical file. So I cannot see the actual contents of Plywood.NativeMethods.cs, it just opens the Plywood.Client.NativeMethods.cs file

Also, if both projects have active generators, then F12 will also show the same file when used from either project

[AArnott]

Thanks. I'll see if I can repro the BOOL bug and get a fix.

For the bonus bug, can you please file that against the dotnet/roslyn repo, as they own that?

[AArnott]

Yup, this is biting me too.

[TIPConsulting]

Looks like the "bonus bug" has a fix in the pipeline: dotnet/roslyn#50714