Re: Bug in SRT generation for procs in .cmm files?

The main problem I'm trying to solve is explained in my comment [1]. Basically when building .cmm files the new SRT algorithm re-order definitions in a way that breaks dependency ordering, which in turn breaks C backend, because in C we should declare before using. (see my comment for why we don't have this problem when building Haskell modules) If we don't allow defining CAFFY things in Cmm files then I can simply not do SRT analysis on Cmm files and avoid the problem. Ömer [1]: https://gitlab.haskell.org/ghc/ghc/merge_requests/1304#note_248547 Ben Gamari , 23 Oca 2020 Per, 15:17 tarihinde şunu yazdı:

While it's true that in principle one could imagine a case where you would want a CAFfy Cmm proc, I can't think of any stuck cases in the RTS today. Consequently it wouldn't surprise me if this was broken.

Frankly, I wouldn't worry too much about this if it's nontrivial to fix.

Cheers,

- Ben

On January 23, 2020 1:54:04 AM EST, "Ömer Sinan Ağacan" wrote:

...

Hi Simon,

Currently CmmParse only generates CmmLabels for procs, and those are considered non-CAFFY by hasCAF (and thus CmmBuildInfoTables).

As a result if I have two procs in a .cmm file:

- p1, refers to a CAF in base - p2, refers to p1

I *think* (haven't checked) we don't consider p1 as CAFFY, and even if we do, we don't consider p2 as CAFFY becuase the reference from p2 to p1 won't be considered CAFFY by hasCAF.

So we currently can't define a CAFFY Cmm proc in .cmm files as the SRT algorithm will never build SRTs for procs in .cmm files.

Is this intentional? I'd expect this to be possible, because there's nothing preventing me from referring to a CAFFY definition in a library (e.g. base) in a .cmm file, but doing this would be a bug in runtime.

Thanks,

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