Elaborate chisel type annotation from firtool to generate debug information for the Tywaves project

[rameloni]

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@fabianschuiki I created this issue to keep talking about the conversation we started here: https://github.com/chipsalliance/chisel/issues/4015#issuecomment-2077714172

I added attributes to debug variable to store the chisel type name and, eventually, the constructor parameters in the debug dialect (and maybe in dbg.struct and dbg.array as well).

However, I may need to create a dbg variable for each sub field, recursively, of aggregates. Is there a reason why values in dbg.struct/dbg.array are of Firrtl types rather than dbg.variable type in MaterializeDebugInfo?

[sequencer]

I think we can to expose the chisel type via compiler plugin like what we did in the source info. But what on earth is a chisel type? That’s the fundamental question(we need specification)

[rameloni]

I think we can to expose the chisel type via compiler plugin like what we did in the source info.

I already managed to expose source level information from chisel to firrtl and firtool. In the meantime I also managed to read this information from firtool, processing it into proper debug variables and updating hgldd/emitting a new file format.

But what on earth is a chisel type? That’s the fundamental question(we need specification)

Whit chisel type refer to the type of the scala variable in the source chisel code. In the following example:

class MyBundle(size: Int) extends Bundle {
   val a = Bool()
   val b = SInt(size.W)
   val nested = new Bundle {
      val x = UInt(8.W)
   }
}
val inBundle  = IO(Input(new MyBundle(10)))
val wireBundle = Wire(new MyBundle(7))
val outBundle = IO(Output(new MyBundle(9)))) 

The types would be

Variable	Type
inBundle	IO[MyBundle(10)]
wireBundle	Wire[MyBundle(7)]
outBundle	IO[MyBundle(9)]
inBundle.a	IO[Bool]
inBundle.b	IO[SInt<10>]
inBundle.nested	IO[AnonymousBundle]
inBundle.nested.x	IO[UInt<8>]
...	...

Namely, I refer to anything represented in this table, including user-defined types: https://raw.githubusercontent.com/chipsalliance/chisel/main/docs/src/images/type_hierarchy.svg?sanitize=true This is basically the information I'm trying to emit in a file format similar to hgldd: https://github.com/chipsalliance/chisel/issues/4015#issuecomment-2066101886