[Git][ghc/ghc][wip/T23479] 6 commits: Desugaring, plus -Wincomplete-record-selectors
Serge S. Gulin (@gulin.serge)
gitlab at gitlab.haskell.org
Tue Oct 15 10:51:33 UTC 2024
Serge S. Gulin pushed to branch wip/T23479 at Glasgow Haskell Compiler / GHC
Commits:
81a570bf by Sebastian Graf at 2024-10-14T22:15:31-04:00
Desugaring, plus -Wincomplete-record-selectors
This commit does several related things:
* Major refactor of the handling of applications in the desugarer.
Now all applications are handled in `dsApp`, `ds_app` and related
functions. This dramatically simplifies the code and removes
complicated cruft that had accumulated. Hooray.
Fixes #25281.
* Improve the handling of -Wincomplete-record-selectors.
We now incorporate the result type of unsaturated record selector
applications as well as consider long-distance information in
getField applications.
Plus, the implmentation now builds the improved `dsApp` stuff
above, so it is much easier to understand.
Plus, incorporates improved error message wording suggested
by Adam Gundry in !12685.
Fixes #24824, #24891
See the long Note [Detecting incomplete record selectors]
* Add -Wincomplete-record-selectors to -Wall, as specified in
GHC Proposal 516.
To do this, I also had to add -Wno-incomplete-record-selectors
to the build flags for Cabal in GHC's CI. See
hadrian/src/Settings/Warnings.hs. We can remove this when
Cabal is updated so that it doesn't trigger the warning:
https://github.com/haskell/cabal/issues/10402
2.6% decrease in compile time allocation in RecordUpPerf
Metric Decrease:
RecordUpdPerf
- - - - -
ae7bc08e by Simon Peyton Jones at 2024-10-14T22:15:31-04:00
Elmininate incomplete record selectors
This patch is a pure refactor of GHC's source code, to avoid the use
of partial record selectors. It was provoked by adding
-Wincomplete-record-selectors to -Wall (as the GHC Proposal specified),
which in turn showed up lots of places where GHC was using incomplete
record selectors.
This patch does mostly-simple refactoring to make it clear to the pattern
match checker that there is in fact no partiality.
There is one externally-visible change: I changed the data type HoleFit
to split out the two cases
data HoleFit = TcHoleFit TcHoleFit | RawHoleFit SDoc
data TcHoleFit = HoleFit { ...lots of fields }
There are large swathes of code that just deal with `TcHoleFit`, and
having it as a separate data types makes it apparent that `RawHoleFit`
can't occur.
This makes it much better -- but the change is visible in the
HolePlugin interface. I decided that there are so few clients of this
API that it's worth the change.
I moved several functions from Language.Haskell.Syntax to GHC.Hs.
Reason, when instantiated at (GhcPass _), the extension data construtcor
is guaranteed unused, and that justifies omitted patterns in these
functions. By putting them in GHC.Hs.X I can specialise the type for
(GhcPass _) and thereby make the function total.
An interesting side-light is that there were a few local function
definitions without a type signature, like this one in GHC.Parser.Header
convImport (L _ i) = (ideclPkgQual i, reLoc $ ideclName i)
This is fully closed, and so is generalised; but that generalises
it to any old pass, not (GhcPass _), so GHC rightly complains about the
use of the selector `ideclPkgQual`. I added a type signature to `i`, thus
convImport (L _ (i::ImportDecl GhcPs))
= (ideclPkgQual i, reLoc $ ideclName i)
which specialised the function enough to make the record selector complete.
Quite a surprising consequence of local let-generalisation!
- - - - -
6a067226 by Simon Peyton Jones at 2024-10-14T22:15:31-04:00
Add -Werror=-Wno-error=incomplete-record-selectors to hadrian-multi
In the main MR, -Wall now includes -Wincomplete-record-selectors.
However `hadrian-multi` has many, many warnings about incomplete
record selectors, so this patch stops those warnings being treated
as errors. (See discussion on !13308.)
A better fix would be to remove the use of incomplete record
selectors, since each of them represents a potential crash.
- - - - -
edeafc14 by Ben Gamari at 2024-10-14T22:16:08-04:00
users-guide: Document field coalescence
- - - - -
55b83587 by ARATA Mizuki at 2024-10-14T22:16:49-04:00
LLVM backend: Use correct rounding for Float literals
Fixes #22033
- - - - -
1d0c0ea5 by Serge S. Gulin at 2024-10-15T13:51:23+03:00
JS: Re-add optimization for literal strings in genApp (fixes #23479)
Based on https://gitlab.haskell.org/ghc/ghc/-/merge_requests/10588/
Co-authored-by: Sylvain Henry <sylvain at haskus.fr>
Co-authored-by: Andrei Borzenkov <root at sandwitch.dev>
Co-authored-by: Danil Berestov <goosedb at yandex.ru>
-------------------------
Metric Decrease:
T25046_perf_size_gzip
size_hello_artifact
size_hello_artifact_gzip
size_hello_unicode
size_hello_unicode_gzip
-------------------------
- - - - -
30 changed files:
- .gitlab-ci.yml
- compiler/GHC/Builtin/Names.hs
- compiler/GHC/CmmToAsm/Dwarf/Types.hs
- compiler/GHC/CmmToAsm/Reg/Graph/Stats.hs
- compiler/GHC/CmmToLlvm/CodeGen.hs
- compiler/GHC/CmmToLlvm/Data.hs
- compiler/GHC/Core.hs
- compiler/GHC/Core/Coercion.hs
- compiler/GHC/Core/ConLike.hs
- compiler/GHC/Core/FVs.hs
- compiler/GHC/Core/LateCC/OverloadedCalls.hs
- compiler/GHC/Core/Lint.hs
- compiler/GHC/Core/Opt/Arity.hs
- compiler/GHC/Core/Opt/CprAnal.hs
- compiler/GHC/Core/Opt/DmdAnal.hs
- compiler/GHC/Core/Opt/Simplify/Env.hs
- compiler/GHC/Core/Opt/Simplify/Utils.hs
- compiler/GHC/Core/Opt/SpecConstr.hs
- compiler/GHC/Core/Rules.hs
- compiler/GHC/Core/SimpleOpt.hs
- compiler/GHC/Core/Subst.hs
- compiler/GHC/Core/Type.hs
- compiler/GHC/Core/Utils.hs
- compiler/GHC/CoreToIface.hs
- compiler/GHC/Driver/Flags.hs
- compiler/GHC/Driver/Session.hs
- compiler/GHC/Hs/Binds.hs
- compiler/GHC/Hs/Decls.hs
- compiler/GHC/Hs/Expr.hs
- compiler/GHC/Hs/Extension.hs
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0cc2c9e9ab8428e6182bd9d387f5eb887cff2c6c...1d0c0ea515c2e1d865240cfa4dec564a9d6442fb
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0cc2c9e9ab8428e6182bd9d387f5eb887cff2c6c...1d0c0ea515c2e1d865240cfa4dec564a9d6442fb
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