Simon Peyton Jones pushed to branch wip/T26681 at Glasgow Haskell Compiler / GHC
Commits:
db1ce858 by sheaf at 2025-12-22T17:11:17-05:00
Do deep subsumption when computing valid hole fits
This commit makes a couple of improvements to the code that
computes "valid hole fits":
1. It uses deep subsumption for data constructors.
This matches up the multiplicities, as per
Note [Typechecking data constructors].
This fixes #26338 (test: LinearHoleFits).
2. It now suggests (non-unidirectional) pattern synonyms as valid
hole fits. This fixes #26339 (test: PatSynHoleFit).
3. It uses 'stableNameCmp', to make the hole fit output deterministic.
-------------------------
Metric Increase:
hard_hole_fits
-------------------------
- - - - -
72ee9100 by sheaf at 2025-12-22T17:11:17-05:00
Speed up hole fits with a quick pre-test
This speeds up the machinery for valid hole fits by doing a small
check to rule out obviously wrong hole fits, such as:
1. A hole fit identifier whose type has a different TyCon at the head,
after looking through foralls and (=>) arrows, e.g.:
hole_ty = Int
cand_ty = Maybe a
or
hole_ty = forall a b. a -> b
cand_ty = forall x y. Either x y
2. A hole fit identifier that is not polymorphic when the hole type
is polymorphic, e.g.
hole_ty = forall a. a -> a
cand_ty = Int -> Int
-------------------------
Metric Decrease:
hard_hole_fits
-------------------------
- - - - -
30e513ba by Cheng Shao at 2025-12-22T17:12:00-05:00
configure: remove unused win32-tarballs.md5sum
This patch removes the unused `win32-tarballs.md5sum` file from the
tree. The current mingw tarball download logic in
`mk/get-win32-tarballs.py` fetches and checks against `SHA256SUM` from
the same location where the tarballs are fetched, and this file has
been unused for a few years.
- - - - -
a2d52b3b by Wolfgang Jeltsch at 2025-12-23T04:47:33-05:00
Add an operation `System.IO.hGetNewlineMode`
This commit also contains some small code and documentation changes for
related operations, for the sake of consistency.
- - - - -
b26d134a by Cheng Shao at 2025-12-23T04:48:15-05:00
rts: opportunistically reclaim slop space in shrinkMutableByteArray#
Previously, `shrinkMutableByteArray#` shrinks a `MutableByteArray#`
in-place by assigning the new size to it, and zeroing the extra slop
space. That slop space is not reclaimed and wasted. But it's often the
case that we allocate a `MutableByteArray#` upfront, then shrink it
shortly after, so the `MutableByteArray#` closure sits right at the
end of a nursery block; this patch identifies such chances, and also
shrink `bd->free` if possible, reducing heap space fragmentation.
Co-authored-by: Codex
-------------------------
Metric Decrease:
T10678
-------------------------
- - - - -
c013db53 by Simon Peyton Jones at 2025-12-23T16:43:05+00:00
Add missing InVar->OutVar lookup in SetLevels
As #26681 showed, the SetLevels pass was failing to map an InVar to
an OutVar. Very silly! I'm amazed it hasn't broken before now.
I have improved the type singatures (to mention InVar and OutVar)
so it's more obvious what needs to happen.
- - - - -
37d1d895 by Simon Peyton Jones at 2025-12-23T16:43:05+00:00
Wibbles to perf
- - - - -
55e131c1 by Simon Peyton Jones at 2025-12-23T16:43:05+00:00
Wibble
- - - - -
44 changed files:
- .gitattributes
- compiler/GHC/Core/DataCon.hs
- compiler/GHC/Core/Opt/SetLevels.hs
- compiler/GHC/Tc/Errors/Hole.hs
- compiler/GHC/Tc/Errors/Hole/FitTypes.hs
- compiler/GHC/Tc/Errors/Ppr.hs
- compiler/GHC/Tc/Gen/App.hs
- compiler/GHC/Tc/Utils/Unify.hs
- docs/users_guide/9.16.1-notes.rst
- libraries/base/changelog.md
- libraries/base/src/System/IO.hs
- libraries/ghc-internal/src/GHC/Internal/IO/Handle.hs
- libraries/ghc-internal/src/GHC/Internal/System/IO.hs
- − mk/win32-tarballs.md5sum
- rts/PrimOps.cmm
- testsuite/tests/ghci/scripts/T8353.stderr
- testsuite/tests/interface-stability/base-exports.stdout
- testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
- testsuite/tests/interface-stability/base-exports.stdout-mingw32
- testsuite/tests/interface-stability/base-exports.stdout-ws-32
- testsuite/tests/overloadedrecflds/should_fail/DRFHoleFits.stderr
- testsuite/tests/perf/compiler/hard_hole_fits.stderr
- testsuite/tests/plugins/test-hole-plugin.stderr
- + testsuite/tests/simplCore/should_compile/T26681.hs
- testsuite/tests/simplCore/should_compile/all.T
- testsuite/tests/th/T15321.stderr
- testsuite/tests/typecheck/should_compile/T13050.stderr
- testsuite/tests/typecheck/should_compile/T14273.stderr
- testsuite/tests/typecheck/should_compile/T14590.stderr
- testsuite/tests/typecheck/should_compile/T25180.stderr
- testsuite/tests/typecheck/should_compile/abstract_refinement_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/constraint_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/free_monad_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/hole_constraints.stderr
- testsuite/tests/typecheck/should_compile/holes.stderr
- testsuite/tests/typecheck/should_compile/holes2.stderr
- testsuite/tests/typecheck/should_compile/holes3.stderr
- testsuite/tests/typecheck/should_compile/refinement_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/subsumption_sort_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/type_in_type_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/valid_hole_fits.stderr
- testsuite/tests/typecheck/should_compile/valid_hole_fits_interactions.stderr
- testsuite/tests/typecheck/should_fail/T14884.stderr
- utils/deriveConstants/Main.hs
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/cce457645c24de4d729142e07e89048...
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/cce457645c24de4d729142e07e89048...
You're receiving this email because of your account on gitlab.haskell.org.
