INTERNAL Oops, forgot to attach the updated program
-----Original Message-----
From: Erdi, Gergo
Sent: Wednesday, August 25, 2021 10:37 AM
To: Matthew Pickering <matthewtpicker...@gmail.com>
Cc: GHC <ghc-devs@haskell.org>; ge...@erdi.hu; Montelatici, Raphael Laurent
<raphael.montelat...@sc.com>
Subject: Re: Where (else) do I need to register instances from loaded modules?
Hi,
Thanks Matt! Unfortunately, I couldn't get it working even with these
suggestions.
1. I changed registerModule so that it only changes the HPT when toUnitId
(moduleUnit mod) == homeUnitId (hsc_dflags env). But I'm pretty sure this will
be vacuously true, since the unit of the module comes from prepareModule
setting the home unit before the call to `downsweep`.
TBH I don't understand the whole idea behind the home package, and maybe all my
pain comes from misusing packages in the first place. As you can see in the
original code I've sent, I'm loading modules from different units; in my real
use case, I'd even like to do things like load module1 from unit1, then module2
from unit2, then module3 from unit1 again -- basically just using the units as
a cheap way to classify modules so that later downstream, I can make decisions
based on the unit of the module of the source of a given definition. Should I
give up on this idea, is this going to lead to problems later on?
2. I also changed mkModIface to fill in the `deps` and while I'm at it, the
`usages` field, by copy-pasting more code from mkIfaceTc. I'm really starting
to think that I'd be better off just changing mkIfaceTc to return a
PartialModIface... Anyway, the new definitions of `deps` and `usages` are:
let pluginModules = map lpModule (cachedPlugins (hsc_dflags hsc_env))
unit_id = homeUnitId (hsc_dflags hsc_env)
deps <- mkDependencies
unit_id (map mi_module pluginModules) tcg
dep_files <- readIORef dependent_files
let used_names = mkUsedNames tcg
usages <- mkUsageInfo hsc_env this_mod (imp_mods imports) used_names
dep_files merged pluginModules
With these changes applied, I am still seeing the same error. Printing shows
that `dep_orphs deps` is empty for Instance.src; further tracing, in turn,
shows that `imp_orphs . tcg_imports $ tcg` is also empty!
I have also found the wording in the documentation regarding dep_orphs
confusing: it sounds like, in my case, this would mean that Use has a
dependency on Instance, because it is using an orphan instance from there. But
my problems are way before I am making a ModIface for Use, since it fails
already during typechecking. But you saying the problem is the incomplete deps
in ModIface must mean that dep_orphs needs to be filled in the ModIface for
Instance (or, oh god I hope not, Class), right?
If I sound somewhat confused, rest assured that in reality I am even MORE
confused!
Any further advice welcome,
Gergo
-----Original Message-----
From: Matthew Pickering <matthewtpicker...@gmail.com>
Sent: Tuesday, August 24, 2021 5:16 PM
To: Erdi, Gergo <gergo.e...@sc.com>
Cc: GHC <ghc-devs@haskell.org>; ge...@erdi.hu; Montelatici, Raphael Laurent
<raphael.montelat...@sc.com>
Subject: [External] Re: Where (else) do I need to register instances from
loaded modules?
Hi Gergo,
Some things I noticed:
* The HPT only contains modules from the current home unit. It seems that
registerModule ignores this so you break this invariant.
* It seems that `Instance` contains an orphan, but you don't fill in the `deps`
field when making a `ModIface`, which should contain all the orphan modules
below the module you are compiling.
I think that if you fill in `deps` correctly then things may work out.
`Dependencies` eventually becomes `ImportAvail`, which gets consulted by
`tcVisibleOrphanMods` which is called in `tcGetInstEnvs` which is called by
`matchInstEnv`.
Matt
This email and any attachments are confidential and may also be privileged. If
you are not the intended recipient, please delete all copies and notify the
sender immediately. You may wish to refer to the incorporation details of
Standard Chartered PLC, Standard Chartered Bank and their subsidiaries at
https: //www.sc.com/en/our-locations
Where you have a Financial Markets relationship with Standard Chartered PLC,
Standard Chartered Bank and their subsidiaries (the "Group"), information on
the regulatory standards we adhere to and how it may affect you can be found in
our Regulatory Compliance Statement at https: //www.sc.com/rcs/ and Regulatory
Compliance Disclosures at http: //www.sc.com/rcs/fm
Insofar as this communication is not sent by the Global Research team and
contains any market commentary, the market commentary has been prepared by the
sales and/or trading desk of Standard Chartered Bank or its affiliate. It is
not and does not constitute research material, independent research,
recommendation or financial advice. Any market commentary is for information
purpose only and shall not be relied on for any other purpose and is subject to
the relevant disclaimers available at https:
//www.sc.com/en/regulatory-disclosures/#market-disclaimer.
Insofar as this communication is sent by the Global Research team and contains
any research materials prepared by members of the team, the research material
is for information purpose only and shall not be relied on for any other
purpose, and is subject to the relevant disclaimers available at https:
//research.sc.com/research/api/application/static/terms-and-conditions.
Insofar as this e-mail contains the term sheet for a proposed transaction, by
responding affirmatively to this e-mail, you agree that you have understood the
terms and conditions in the attached term sheet and evaluated the merits and
risks of the transaction. We may at times also request you to sign the term
sheet to acknowledge the same.
Please visit https: //www.sc.com/en/regulatory-disclosures/dodd-frank/ for
important information with respect to derivative products.
Main.hs
Description: Main.hs
_______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
