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f8d9d016
by Andrew Lelechenko at 2025-07-22T21:13:28-04:00
Fix issues with toRational for types capable to represent infinite and not-a-number values
This commit fixes all of the following pitfalls:
> toRational (read "Infinity" :: Double)
179769313486231590772930519078902473361797697894230657273430081157732675805500963132708477322407536021120113879871393357658789768814416622492847430639474124377767893424865485276302219601246094119453082952085005768838150682342462881473913110540827237163350510684586298239947245938479716304835356329624224137216 % 1
> toRational (read "NaN" :: Double)
269653970229347386159395778618353710042696546841345985910145121736599013708251444699062715983611304031680170819807090036488184653221624933739271145959211186566651840137298227914453329401869141179179624428127508653257226023513694322210869665811240855745025766026879447359920868907719574457253034494436336205824 % 1
> realToFrac (read "NaN" :: Double) -- With -O0
Infinity
> realToFrac (read "NaN" :: Double) -- With -O1
NaN
> realToFrac (read "NaN" :: Double) :: CDouble
Infinity
> realToFrac (read "NaN" :: CDouble) :: Double
Infinity
Implements https://github.com/haskell/core-libraries-committee/issues/338
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5dabc718
by Zubin Duggal at 2025-07-22T21:14:10-04:00
haddock: Don't warn about missing link destinations for derived names.
Fixes #26114
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9c3a0937
by Matthew Pickering at 2025-07-22T21:14:52-04:00
template haskell: use a precise condition when implicitly lifting
Implicit lifting corrects a level error by replacing references to `x`
with `$(lift x)`, therefore you can use a level `n` binding at level `n
+ 1`, if it can be lifted.
Therefore, we now have a precise check that the use level is 1 more than
the bind level.
Before this bug was not observable as you only had 0 and 1 contexts but
it is easily evident when using explicit level imports.
Fixes #26088
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5144b22f
by Andreas Klebinger at 2025-07-22T21:15:34-04:00
Add since tag and more docs for do-clever-arg-eta-expansion
Fixes #26113
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c865623b
by Andreas Klebinger at 2025-07-22T21:15:34-04:00
Add since tag for -fexpose-overloaded-unfoldings
Fixes #26112
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49a44ab7
by Simon Hengel at 2025-07-23T17:59:55+07:00
Refactor GHC.Driver.Errors.printMessages
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84711c39
by Simon Hengel at 2025-07-23T18:27:34+07:00
Respect `-fdiagnostics-as-json` for error messages from pre-processors
(fixes #25480)
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d046b5ab
by Simon Hengel at 2025-07-24T06:12:05-04:00
Include the rendered message in -fdiagnostics-as-json output
This implements #26173.
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d2b89603
by Ben Gamari at 2025-07-24T06:12:47-04:00
rts/Interpreter: Factor out ctoi tuple info tables into data
Instead of a massive case let's put this into data which we can reuse
elsewhere.
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4bc78496
by Sebastian Graf at 2025-07-24T16:19:34-04:00
CprAnal: Detect recursive newtypes (#25944)
While `cprTransformDataConWork` handles recursive data con workers, it
did not detect the case when a newtype is responsible for the recursion.
This is now detected in the `Cast` case of `cprAnal`.
The same reproducer made it clear that `isRecDataCon` lacked congruent
handling for `AppTy` and `CastTy`, now fixed.
Furthermore, the new repro case T25944 triggered this bug via an
infinite loop in `cprFix`, caused by the infelicity in `isRecDataCon`.
While it should be much less likely to trigger such an infinite loop now
that `isRecDataCon` has been fixed, I made sure to abort the loop after
10 iterations and emitting a warning instead.
Fixes #25944.
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0a583689
by Sylvain Henry at 2025-07-24T16:20:26-04:00
STM: don't create a transaction in the rhs of catchRetry# (#26028)
We don't need to create a transaction for the rhs of (catchRetry#)
because contrary to the lhs we don't need to abort it on retry. Moreover
it is particularly harmful if we have code such as (#26028):
let cN = readTVar vN >> retry
tree = c1 `orElse` (c2 `orElse` (c3 `orElse` ...))
atomically tree
Because it will stack transactions for the rhss and the read-sets of all
the transactions will be iteratively merged in O(n^2) after the
execution of the most nested retry.
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a49eca26
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Renaming around predicate types
.. we were (as it turned out) abstracting over
type-class selectors in SPECIALISATION rules!
Wibble isEqPred
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f80375dd
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Refactor of Specialise.hs
This patch just tidies up `specHeader` a bit, removing one
of its many results, and adding some comments.
No change in behaviour.
Also add a few more `HasDebugCallStack` contexts.
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1bd12371
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Improve treatment of SPECIALISE pragmas -- again!
This MR does another major refactor of the way that SPECIALISE
pragmas work, to fix #26115, #26116, #26117.
* We now /always/ solve forall-constraints in an all-or-nothing way.
See Note [Solving a Wanted forall-constraint] in GHC.Tc.Solver.Solve
This means we might have unsolved quantified constraints, which need
to be reported. See `inert_insts` in `getUnsolvedInerts`.
* I refactored the short-cut solver for type classes to work by
recursively calling the solver rather than by having a little baby
solver that kept being not clever enough.
See Note [Shortcut solving] in GHC.Tc.Solver.Dict
* I totally rewrote the desugaring of SPECIALISE pragmas, again.
The new story is in Note [Desugaring new-form SPECIALISE pragmas]
in GHC.HsToCore.Binds
Both old-form and new-form SPECIALISE pragmas now route through the same
function `dsSpec_help`. The tricky function `decomposeRuleLhs` is now used only
for user-written RULES, not for SPECIALISE pragmas.
* I improved `solveOneFromTheOther` to account for rewriter sets. Previously
it would solve a non-rewritten dict from a rewritten one. For equalities
we were already dealing with this, in
Some incidental refactoring
* A small refactor: `ebv_tcvs` in `EvBindsBar` now has a list of coercions, rather
than a set of tyvars. We just delay taking the free vars.
* GHC.Core.FVs.exprFVs now returns /all/ free vars.
Use `exprLocalFVs` for Local vars.
Reason: I wanted another variant for /evidence/ variables.
* Ues `EvId` in preference to `EvVar`. (Evidence variables are always Ids.)
Rename `isEvVar` to `isEvId`.
* I moved `inert_safehask` out of `InertCans` and into `InertSet` where it
more properly belongs.
Compiler-perf changes:
* There was a palpable bug (#26117) which this MR fixes in
newWantedEvVar, which bypassed all the subtle overlapping-Given
and shortcutting logic. (See the new `newWantedEvVar`.) Fixing this
but leads to extra dictionary bindings; they are optimised away quickly
but they made CoOpt_Read allocate 3.6% more.
* Hpapily T15164 improves.
* The net compiler-allocation change is 0.0%
Metric Decrease:
T15164
Metric Increase:
CoOpt_Read
T12425
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953fd8f1
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Solve forall-constraints immediately, or not at all
This MR refactors the constraint solver to solve forall-constraints immediately,
rather than emitting an implication constraint to be solved later.
The most immediate motivation was that when solving quantified constraints
in SPECIALISE pragmas, we really really don't want to leave behind half-
solved implications. Also it's in tune with the approach of the new
short-cut solver, which recursively invokes the solver.
It /also/ saves quite a bit of plumbing; e.g
- The `wl_implics` field of `WorkList` is gone,
- The types of `solveSimpleWanteds` and friends are simplified.
- An EvFun contains binding, rather than an EvBindsVar ref-cell that
will in the future contain bindings. That makes `evVarsOfTerm`
simpler. Much nicer.
It also improves error messages a bit.
All described in Note [Solving a Wanted forall-constraint] in
GHC.Tc.Solver.Solve.
One tiresome point: in the tricky case of `inferConstraintsCoerceBased`
we make a forall-constraint. This we /do/ want to partially solve, so
we can infer a suitable context. (I'd be quite happy to force the user to
write a context, bt I don't want to change behavior.) So we want to generate
an /implication/ constraint in `emitPredSpecConstraints` rather than a
/forall-constraint/ as we were doing before. Discussed in (WFA3) of
the above Note.
Incidental refactoring
* `GHC.Tc.Deriv.Infer.inferConstraints` was consulting the state monad for
the DerivEnv that the caller had just consulted. Nicer to pass it as an
argument I think, so I have done that. No change in behaviour.
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6921ab42
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Remove duplicated code in Ast.hs for evTermFreeVars
This is just a tidy up.
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1165f587
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Small tc-tracing changes only