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c77d88fc
by sheaf at 2026-08-13T10:15:22-04:00
Allow rewriting in RuntimeReps for newtype ConPats
This commit implements PHASE 2 of the FixedRuntimeRep plan described in
Note [The Concrete mechanism] in GHC.Tc.Utils.Concrete for newtype
constructor patterns.
In short, GHC now accepts programs of the form
f (MkN x) = ...
in which the argument 'x' of the newtype constructor pattern 'MkN x'
has a representation that is not syntactically concrete, e.g. it can be
'Id IntRep' reducing to 'IntRep'. See T20363{,b,c} for examples.
There are two main parts to the implementation:
1. Typechecking, in GHC.Tc.Gen.Pat.tcDataConPat.
See Note [Typechecking newtype constructor patterns] in GHC.Tc.Gen.Pat.
2. Desugaring. We restructure the code for desugaring pattern matches
by allowing the scrutinised match variable to be casted. This allows
us to accumulate coercions and avoids creating binders at intermediate
types tha don't have a fixed RuntimeRep.
See the revamped Note [Match Ids] in GHC.HsToCore.Monad.
Fixes #20363
-------------------------
Metric Increase:
InstanceMatching
-------------------------
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6ba9dd41
by Wolfgang Jeltsch at 2026-08-13T10:16:07-04:00
Improve the documentation of `--show-iface`
This change in particular gets rid of the claim that `--show-iface`
writes *the* contents of the interface file in question. It doesn’t do
that; it only writes those parts that are likely of interest to a human
reader.
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4bd193fa
by Sylvain Henry at 2026-08-13T10:17:00-04:00
RTS: fix LDV profiler's slop skipping (#27585)
processHeapForDead was the one heap scanner not updated for the slop
marker encoding introduced in #19048. It still assumed slop is zeroed:
while (p < bd->free && !*p) p++; // skip slop
so it stopped at the (StgWord)(-1) sentinel and passed it to
processHeapClosureForDead. IS_FORWARDING_PTR(-1) holds, hence a garbage
size was read out of LDVW and the scan ran off the block, tripping
ASSERT(p == bd->free) on a debug RTS and silently corrupting the census
otherwise.
The loop was hand-copied in four places, so factor it out into skipSlop
in ClosureMacros.h and use it in ProfHeap.c, Sanity.c, Printer.c and
LdvProfile.c.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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1446bb03
by Zubin Duggal at 2026-08-13T10:17:48-04:00
hadrian: Fix links to remaining doc sites to not use the package hash for haddock links
In 07267f79d91169f474cacc8bcd38d76a6e97887d we changed hadrian to not include the package hash in the haddock
directory. This patch takes care of a few remaining links that were missed in that patch
Fixes #27671
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257c3ed7
by Simon Jakobi at 2026-08-13T10:18:29-04:00
Testsuite: widen InstanceMatching acceptance window to 5% (#27673)
...in order to unblock CI.
Assisted-by: Claude Fable 5
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7abd196b
by Vladislav Zavialov at 2026-08-13T15:34:54-04:00
Increase test coverage of diagnostics, batch 2
Add test cases for the previously untested diagnostics:
[GHC-26133] TcRnForeignImportPrimSafeAnn
[GHC-68444] SumAltArityExceeded
[GHC-63966] IllegalSumAlt
[GHC-23882] IllegalDeclaration
[GHC-60220] InvalidCCallImpent
[GHC-18816] RecGadtNoCons
[GHC-38140] GadtNoCons
[GHC-37056] InvalidTypeInstanceHeader
[GHC-78486] InvalidTyFamInstLHS
[GHC-39639] DefaultDataInstDecl
[GHC-78822] AssocDefaultNotAssoc
[GHC-43510] NotSimpleUnliftedType
[GHC-41843] IOResultExpected
[GHC-07641] AtLeastOneArgExpected
[GHC-52886] InvalidTopDecl
Remove unused error constructors:
[GHC-92057] ImportLookupAmbiguous
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41db643e
by Simon Jakobi at 2026-08-13T15:34:55-04:00
testsuite: Drop peak_megabytes_allocated from LinkableUsage tests
LinkableUsage01/02 collected all metrics with a 2% tolerance. For
peak_megabytes_allocated, whose granularity is 1 MB, that window is
under 0.7 MB at this test's ~34 MB peak, so any 1 MB step failed the
test (#27613, #27489). Drop that metric: max_bytes_used guards the
Linkable-retention property with byte granularity, at a tolerance
that still comfortably exceeds the noise observed in CI.
Assisted-by: Claude Fable 5
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e98231d7
by Simon Jakobi at 2026-08-13T15:34:55-04:00
testsuite: Don't truncate fractional baselines when computing bounds
RelativeMetricAcceptanceWindow.get_bounds truncated the baseline with
int() before applying the tolerance. Baselines can be fractional (they
are averaged over several measurements), so this skewed the acceptance
window downwards: in #27613, a baseline of 33.67 at 2% tolerance
yielded bounds (32, 34) instead of (32, 35), rejecting a measurement
that was within tolerance.
Assisted-by: Claude Fable 5