Weird "missing hi file" problem with a serializable Core patch

[Ben Gamari]

Cheng Shao <cheng.shao at tweag.io> writes:

> Hi all,
>
> Following a short chat in #ghc last week, I did a first attempt of
> reusing existing Iface logic to implement serialization for
> codegen-related Core. The implementation is included in the attached
> patch (~100 loc). As a quick and dirty validation of whether it works,
> I also modified the codegen pipeline logic to do a roundtrip: after
> CorePrep, the Core bits are converted to Iface, then we immediately
> convert it back and use it for later compiling.
>
> With the patch applied, stage-1 GHC would produce a "missing hi file"
> error like:
>
> : Bad interface file: _build/stage1/libraries/ghc-prim/build/GHC/Types.hi
>       _build/stage1/libraries/ghc-prim/build/GHC/Types.hi:
> openBinaryFile: does not exist (No such file or directory)
>
Hi Cheng,

Which module is being compiled when this error is produced? Could you
provide -ddump-if-trace output for the failing compilation?

> The error surprises me, since by the time we perform the Core-to-Core
> roundtrip, the .hi file should already have been written to disk. Is
> there anything obviously wrong with the implementation? I'd appreciate
> any pointers or further questions, thanks a lot!
>
Note that interface files are written after the Core pipeline is run.

Cheers,

- Ben

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 487 bytes
Desc: not available
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20200916/9b481127/attachment.sig>