Ömer Sinan Ağacan
However, there is also a slightly more fundamental issue here: GHC's NCG handles DWARF information with block granularity. Fixing this will be a bit more involved. See compiler/nativeGen/Dwarf.hs for details.
One alternative would be to just finish debug information in the LLVM backend and use this instead (originally D2343, although mpickering has a newer version).
But LLVM backend also uses the same debug info we generate for NCG, no? So I think debug info would still be in block granularity?
How hard do you think it would be to do the refactoring to generate debug info for each Cmm source line, instead of each RawCmm block?
I was under the impression that the C-- AST can already capture debug information with arbitrarily fine granularity. However, after looking again at the implementation it looks like you raise a very good point: CmmTick nodes apparently cover the entire block they reside within. This is indeed a problem. I honestly don't know how hard it would be to fix this without serious surgery to the C-- pipeline. It doesn't sound particularly easy. Cheers, - Ben