-
bbaa44a7
by Peng Fan at 2025-07-16T16:50:42-04:00
NCG/LA64: Support finer-grained DBAR hints
For LA664 and newer uarchs, they have made finer granularity hints
available:
Bit4: ordering or completion (0: completion, 1: ordering)
Bit3: barrier for previous read (0: true, 1: false)
Bit2: barrier for previous write (0: true, 1: false)
Bit1: barrier for succeeding read (0: true, 1: false)
Bit0: barrier for succeeding write (0: true, 1: false)
And not affect the existing models because other hints are treated
as 'dbar 0' there.
-
7da86e16
by Andreas Klebinger at 2025-07-16T16:51:25-04:00
Disable -fprof-late-overloaded-calls for join points.
Currently GHC considers cost centres as destructive to
join contexts. Or in other words this is not considered valid:
join f x = ...
in
... -> scc<tick> jmp
This makes the functionality of `-fprof-late-overloaded-calls` not feasible
for join points in general. We used to try to work around this by putting the
ticks on the rhs of the join point rather than around the jump. However beyond
the loss of accuracy this was broken for recursive join points as we ended up
with something like:
rec-join f x = scc<tick> ... jmp f x
Which similarly is not valid as the tick once again destroys the tail call.
One might think we could limit ourselves to non-recursive tail calls and do
something clever like:
join f x = scc<tick> ...
in ... jmp f x
And sometimes this works! But sometimes the full rhs would look something like:
join g x = ....
join f x = scc<tick> ... -> jmp g x
Which, would again no longer be valid. I believe in the long run we can make
cost centre ticks non-destructive to join points. Or we could keep track of
where we are/are not allowed to insert a cost centre. But in the short term I will
simply disable the annotation of join calls under this flag.
-
7ee22fd5
by ARATA Mizuki at 2025-07-17T06:05:30-04:00
x86 NCG: Better lowering for shuffleFloatX4# and shuffleDoubleX2#
The new implementation
* make use of specialized instructions like (V)UNPCK{L,H}{PS,PD}, and
* do not require -mavx.
Close #26096
Co-authored-by: sheaf <sam.derbyshire@gmail.com>
-
c6cd2da1
by Jappie Klooster at 2025-07-17T06:06:20-04:00
Update interact docs to explain about buffering
We need to tell the user to set to the
appropriate buffer format.
Otherwise, this function may get randomly stuck,
or just behave confusingly.
issue: https://gitlab.haskell.org/ghc/ghc/-/issues/26131
NB, I'm running this with cabal *NOT* ghci. ghci messes with buffering anyway.
```haskell
interaction :: String -> String
interaction "jappie" = "hi"
interaction "jakob" = "hello"
interaction x = "unkown input: " <> x
main :: IO ()
main = interact interaction
```
so in my input (prefixed by `>`) I get:
```
> jappie
unkown input: jappie
```
we confirmed later this was due to lack of \n matching.
Anyway movnig on to more unexpected stuff:
```haskell
main :: IO ()
main = do
interact (concatMap interaction . lines)
```
get's stuck forever.
actually `^D` (ctrl+d) unstucks it and runs all input as expected.
for example you can get:
```
> sdfkds
> fakdsf
unkown input: sdfkdsunkown input: fakdsf
```
This program works!
```haskell
interaction :: String -> String
interaction "jappie" = "hi \n"
interaction "jakob" = "hello \n"
interaction x = "unkown input: " <> x <> "\n"
main :: IO ()
main = do
interact (concatMap interaction . lines)
```
the reason is that linebuffering is set for both in and output by default.
so lines eats the input lines, and all the \n postfixes make sure the buffer
is put out.
-
9fa590a6
by Zubin Duggal at 2025-07-17T06:07:03-04:00
fetch_gitlab: Ensure we copy users_guide.pdf and Haddock.pdf to the release docs directory
Fixes #24093
-
cc650b4b
by Andrew Lelechenko at 2025-07-17T12:30:24-04:00
Add Data.List.NonEmpty.mapMaybe
As per https://github.com/haskell/core-libraries-committee/issues/337
-
360fa82c
by Duncan Coutts at 2025-07-17T12:31:14-04:00
base: Deprecate GHC.Weak.Finalize.runFinalizerBatch
https://github.com/haskell/core-libraries-committee/issues/342
-
f4e8466c
by Alan Zimmerman at 2025-07-17T12:31:55-04:00
EPA: Update exact printing based on GHC 9.14 tests
As a result of migrating the GHC ghc-9.14 branch tests to
ghc-exactprint in
https://github.com/alanz/ghc-exactprint/tree/ghc-9.14, a couple of
discrepancies were picked up
- The opening paren for a DefaultDecl was printed in the wrong place
- The import declaration level specifiers were not printed.
This commit adds those fixes, and some tests for them.
The tests brought to light that the ImportDecl ppr instance had not
been updated for level specifiers, so it updates that too.
-
8b731e3c
by Matthew Pickering at 2025-07-21T13:36:43-04:00
level imports: Fix infinite loop with cyclic module imports
I didn't anticipate that downsweep would run before we checked for
cyclic imports. Therefore we need to use the reachability function which
handles cyclic graphs.
Fixes #26087
-
d751a9f1
by Pierre Thierry at 2025-07-21T13:37:28-04:00
Fix documentation about deriving from generics
-
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
-
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
-
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
-
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
-
c865623b
by Andreas Klebinger at 2025-07-22T21:15:34-04:00
Add since tag for -fexpose-overloaded-unfoldings
Fixes #26112
-
49a44ab7
by Simon Hengel at 2025-07-23T17:59:55+07:00
Refactor GHC.Driver.Errors.printMessages
-
84711c39
by Simon Hengel at 2025-07-23T18:27:34+07:00
Respect `-fdiagnostics-as-json` for error messages from pre-processors
(fixes #25480)
-
d046b5ab
by Simon Hengel at 2025-07-24T06:12:05-04:00
Include the rendered message in -fdiagnostics-as-json output
This implements #26173.
-
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.
-
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.
-
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.
-
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
-
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.
-
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
-
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.
-
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.
-
1165f587
by Simon Peyton Jones at 2025-07-25T09:49:58+01:00
Small tc-tracing changes only
-
0776ffe0
by Simon Hengel at 2025-07-26T04:54:20-04:00
Respect `-fdiagnostics-as-json` for core diagnostics (see #24113)
-
cc1116e0
by Andrew Lelechenko at 2025-07-26T04:55:01-04:00
docs: add since pragma to Data.List.NonEmpty.mapMaybe
-
ee2dc248
by Simon Hengel at 2025-07-31T06:25:35-04:00
Update comments on `OptKind` to reflect the code reality
-
b029633a
by Wen Kokke at 2025-07-31T06:26:21-04:00
rts: Disable --eventlog-flush-interval unless compiled with -threaded.
This commit fixes issue #26222:
Using --eventlog-flush-interval with the non-threaded RTS leads to eventlog corruption.
https://gitlab.haskell.org/ghc/ghc/-/issues/26222
This commit makes three changes when code is compiled against the non-threaded RTS:
1. It disables the --eventlog-flush-interval flag.
2. It disables the documentation for the --eventlog-flush-interval flag.
3. It disables the relevant state from RtsConfig and code from Timer.
4. It updates the entry for --eventlog-flush-interval in the users guide.
-
31159f1d
by Wen Kokke at 2025-07-31T06:26:21-04:00
rts: Split T20006 into tests with and without -threaded
-
618687ef
by Simon Hengel at 2025-07-31T06:27:03-04:00
docs/users_guide/win32-dlls.rst: Remove references to `readline`
-
083e40f1
by Rodrigo Mesquita at 2025-08-01T04:38:23-04:00
debugger: Uniquely identify breakpoints by internal id
Since b85b11994e0130ff2401dd4bbdf52330e0bcf776 (support inlining
breakpoints), a breakpoint has been identified at runtime by *two* pairs
of <module,index>.
- The first, aka a 'BreakpointId', uniquely identifies a breakpoint in
the source of a module by using the Tick index. A Tick index can index
into ModBreaks.modBreaks_xxx to fetch source-level information about
where that tick originated.
- When a user specifies e.g. a line breakpoint using :break, we'll reverse
engineer what a Tick index for that line
- We update the `BreakArray` of that module (got from the
LoaderState) at that tick index to `breakOn`.
- A BCO we can stop at is headed by a BRK_FUN instruction. This
instruction stores in an operand the `tick index` it is associated
to. We look it up in the associated `BreakArray` (also an operand)
and check wheter it was set to `breakOn`.
- The second, aka the `ibi_info_mod` + `ibi_info_ix` of the
`InternalBreakpointId`, uniquely index into the `imodBreaks_breakInfo`
-- the information we gathered during code generation about the
existing breakpoint *ocurrences*.
- Note that with optimisation there may be many occurrences of the
same source-tick-breakpoint across different modules. The
`ibi_info_ix` is unique per occurrence, but the `bi_tick_ix` may be
shared. See Note [Breakpoint identifiers] about this.
- Note that besides the tick ids, info ids are also stored in
`BRK_FUN` so the break handler can refer to the associated
`CgBreakInfo`.
In light of that, the driving changes come from the desire to have the
info_id uniquely identify the breakpoint at runtime, and the source tick
id being derived from it:
- An InternalBreakpointId should uniquely identify a breakpoint just
from the code-generation identifiers of `ibi_info_ix` and `ibi_info_mod`.
So we drop `ibi_tick_mod` and `ibi_tick_ix`.
- A BRK_FUN instruction need only record the "internal breakpoint id",
not the tick-level id.
So we drop the tick mod and tick index operands.
- A BreakArray should be indexed by InternalBreakpointId rather than
BreakpointId
That means we need to do some more work when setting a breakpoint.
Specifically, we need to figure out the internal ids (occurrences of a
breakpoint) from the source-level BreakpointId we want to set the
breakpoint at (recall :break refers to breaks at the source level).
Besides this change being an improvement to the handling of breakpoints
(it's clearer to have a single unique identifier than two competing
ones), it unlocks the possibility of generating "internal" breakpoints
during Cg (needed for #26042).
It should also be easier to introduce multi-threaded-aware `BreakArrays`
following this change (needed for #26064).
Se also the new Note [ModBreaks vs InternalModBreaks]
On i386-linux:
-------------------------
Metric Decrease:
interpreter_steplocal
-------------------------
-
bf03bbaa
by Simon Hengel at 2025-08-01T04:39:05-04:00
Don't use MCDiagnostic for `ghcExit`
This changes the error message of `ghcExit` from
```
<no location info>: error:
Compilation had errors
```
to
```
Compilation had errors
```
-
a889ec75
by Simon Hengel at 2025-08-01T04:39:05-04:00
Respect `-fdiagnostics-as-json` for driver diagnostics (see #24113)
-
81577fe7
by Ben Gamari at 2025-08-02T04:29:39-04:00
configure: Allow override of CrossCompiling
As noted in #26236, the current inference logic is a bit simplistic. In
particular, there are many cases (e.g. building for a new libc) where
the target and host triples may differ yet we are still able to run the
produced artifacts as native code.
Closes #26236.
-
01136779
by Andreas Klebinger at 2025-08-02T04:30:20-04:00
rts: Support COFF BigObj files in archives.
-
1f9e4f54
by Stephen Morgan at 2025-08-03T15:14:08+10:00
refactor: Modify Data.List.sortOn to use (>) instead of compare. (#26184)
This lets a more efficient (>) operation be used if one exists.
This is technically a breaking change for malformed Ord instances, where
x > y is not equivalent to compare x y == GT.
Discussed by the CLC in issue #332: https://github.com/haskell/core-libraries-committee/issues/332
-
4f6bc9cf
by fendor at 2025-08-04T17:50:06-04:00
Revert "base: Expose Backtraces constructor and fields"
This reverts commit 17db44c5b32fff82ea988fa4f1a233d1a27bdf57.
-
bcdec657
by Zubin Duggal at 2025-08-05T10:37:29+05:30
compiler: Export a version of `newNameCache` that is not prone to footguns.
`newNameCache` must be initialized with both a non-"reserved" unique tag, as well
as a list of known key names. Failing to do so results in hard to debug unique conflicts.
It is difficult for API users to tell which unique tags are safe to use. So instead of leaving
this up to the user to decide, we now export a version of `newNameCache` which uses a guaranteed
non-reserved unique tag. In fact, this is now the way the unique tag is initialized for all invocations
of the compiler.
The original version of `newNameCache` is now exported as `newNameCache'` for advanced users.
We also deprecate `initNameCache` as it is also prone to footguns and is completely subsumed in
functionality by `newNameCache` and `newNameCache'`.
Fixes #26135 and #26055
-
57d3b4a8
by Andrew Lelechenko at 2025-08-05T18:36:31-04:00
hadrian: bump Stackage snapshot to LTS 24.2 / GHC 9.10.2
In line with #25693 we should use GHC 9.10 as a boot compiler,
while Hadrian stack.yaml was stuck on GHC 9.6.
-
c2a78cea
by Peng Fan at 2025-08-05T18:37:27-04:00
NCG/LA64: implement atomic write with finer-grained DBAR hints
Signed-off-by: Peng Fan <fanpeng@loongson.cn>
-
95231c8e
by Teo Camarasu at 2025-08-06T08:35:58-04:00
CODEOWNERS: add CLC as codeowner of base
We also remove hvr, since I think he is no longer active
-
77df0ded
by Andrew Lelechenko at 2025-08-06T08:36:39-04:00
Bump submodule text to 2.1.3
-
8af260d0
by Nikolaos Chatzikonstantinou at 2025-08-06T08:37:23-04:00
docs: fix internal import in getopt examples
This external-facing doc example shouldn't mention GHC internals when
using 'fromMaybe'.
-
69cc16ca
by Marc Scholten at 2025-08-06T15:51:28-04:00
README: Add note on ghc.nix
-
93a2f450
by Daniel Díaz at 2025-08-06T15:52:14-04:00
Link to the "Strict Bindings" docs from the linear types docs
Strict Bidings are relevant for the kinds of multiplicity annotations
linear lets support.
-
246b7853
by Matthew Pickering at 2025-08-07T06:58:30-04:00
level imports: Check the level of exported identifiers
The level imports specification states that exported identifiers have to
be at level 0. This patch adds the requird level checks that all
explicitly mentioned identifiers occur at level 0.
For implicit export specifications (T(..) and module B), only level 0
identifiers are selected for re-export.
ghc-proposal: https://github.com/ghc-proposals/ghc-proposals/pull/705
Fixes #26090
-
358bc4fc
by fendor at 2025-08-07T06:59:12-04:00
Bump GHC on darwin CI to 9.10.1
-
1903ae35
by Matthew Pickering at 2025-08-07T12:21:10+01:00
ipe: Place strings and metadata into specific .ipe section
By placing the .ipe metadata into a specific section it can be stripped
from the final binary if desired.
```
objcopy --remove-section .ipe <binary>
upx <binary>
```
Towards #21766
-
c80dd91c
by Matthew Pickering at 2025-08-07T12:22:42+01:00
ipe: Place magic word at the start of entries in the .ipe section
The magic word "IPE\nIPE\n" is placed at the start of .ipe sections,
then if the section is stripped, we can check whether the section starts
with the magic word or not to determine whether there is metadata
present or not.
Towards #21766
-
cab42666
by Matthew Pickering at 2025-08-07T12:22:42+01:00
ipe: Use stable IDs for IPE entries
IPEs have historically been indexed and reported by their address.
This makes it impossible to compare profiles between runs, since the
addresses may change (due to ASLR) and also makes it tricky to separate
out the IPE map from the binary.
This small patch adds a stable identifier for each IPE entry.
The stable identifier is a single 64 bit word. The high-bits are a
per-module identifier and the low bits identify which entry in each
module.
1. When a node is added into the IPE buffer it is assigned a unique
identifier from an incrementing global counter.
2. Each entry already has an index by it's position in the
`IpeBufferListNode`.
The two are combined together by the `IPE_ENTRY_KEY` macro.
Info table profiling uses the stable identifier rather than the address
of the info table.
The benefits of this change are:
* Profiles from different runs can be easily compared
* The metadata can be extracted from the binary (via the eventlog for
example) and then stripped from the executable.
Fixes #21766
-
2860a9a5
by Simon Peyton Jones at 2025-08-07T20:29:18-04:00
In TcSShortCut, typechecker plugins should get empty Givens
Solving in TcShortCut mode means /ignoring the Givens/. So we
should not pass them to typechecker plugins!
Fixes #26258.
This is a fixup to the earlier MR:
commit 1bd12371feacc52394a0e660ef9349f9e8ee1c06
Author: Simon Peyton Jones <simon.peytonjones@gmail.com>
Date: Mon Jul 21 10:04:49 2025 +0100
Improve treatment of SPECIALISE pragmas -- again!
-
2157db2d
by sterni at 2025-08-08T15:32:39-04:00
hadrian: enable terminfo if --with-curses-* flags are given
The GHC make build system used to support WITH_TERMINFO in ghc.mk which
allowed controlling whether to build GHC with terminfo or not. hadrian
has replaced this with a system where this is effectively controlled by
the cross-compiling setting (the default WITH_TERMINFO value was bassed
on CrossCompiling, iirc).
This behavior is undesireable in some cases and there is not really a
good way to work around it. Especially for downstream packagers,
modifying this via UserSettings is not really feasible since such a
source file has to be kept in sync with Settings/Default.hs manually
since it can't import Settings.Default or any predefined Flavour
definitions.
To avoid having to add a new setting to cfg/system.config and/or a new
configure flag (though I'm happy to implement both if required), I've
chosen to take --with-curses-* being set explicitly as an indication
that the user wants to have terminfo enabled. This would work for
Nixpkgs which sets these flags [1] as well as haskell.nix [2] (which
goes to some extreme measures [3] [4] to force terminfo in all scenarios).
In general, I'm an advocate for making the GHC build be the same for
native and cross insofar it is possible since it makes packaging GHC and
Haskell related things while still supporting cross much less
compilicated. A more minimal GHC with reduced dependencies should
probably be a specific flavor, not the default.
Partially addresses #26288 by forcing terminfo to be built if the user
explicitly passes configure flags related to it. However, it isn't built
by default when cross-compiling yet nor is there an explicit way to
control the package being built.
[1]: https://github.com/NixOS/nixpkgs/blob/3a7266fcefcb9ce353df49ba3f292d06443760bb/pkgs/development/compilers/ghc/common-hadrian.nix#L513-L515
[2]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L185
[3]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L678-L682
[4]: https://github.com/input-output-hk/haskell.nix/blob/6eaafcdf04bab7be745d1aa4f74d2cc85700042b/compiler/ghc/default.nix#L772-L773
-
b3c31488
by David Feuer at 2025-08-08T15:33:21-04:00
Add default QuasiQuoters
Add `defaultQuasiQuoter` and `namedDefaultQuasiQuoter` to make it easier
to write `QuasiQuoters` that give helpful error messages when they're
used in inappropriate contexts.
Closes #24434.
-
03555ed8
by Sylvain Henry at 2025-08-10T22:20:57-04:00
Handle non-fractional CmmFloats in Cmm's CBE (#26229)
Since f8d9d016305be355f518c141f6c6d4826f2de9a2, toRational for Float and
Double converts float's infinity and NaN into Rational's infinity and
NaN (respectively 1%0 and 0%0).
Cmm CommonBlockEliminator hashing function needs to take these values
into account as they can appear as literals now. See added testcase.
-
6c956af3
by J. Ryan Stinnett at 2025-08-10T22:21:42-04:00
Fix extensions list in `DoAndIfThenElse` docs
-
6dc420b1
by J. Ryan Stinnett at 2025-08-10T22:21:42-04:00
Document status of `RelaxedPolyRec` extension
This adds a brief extension page explaining the status of the
`RelaxedPolyRec` extension. The behaviour of this mode is already
explained elsewhere, so this page is mainly for completeness so that
various lists of extensions have somewhere to point to for this flag.
Fixes #18630
-
18036d52
by Simon Peyton Jones at 2025-08-11T11:31:20-04:00
Take more care in zonkEqTypes on AppTy/AppTy
This patch fixes #26256.
See Note [zonkEqTypes and the PKTI] in GHC.Tc.Solver.Equality
-
c8d76a29
by Zubin Duggal at 2025-08-11T11:32:02-04:00
ci: upgrade bootstrap compiler on windows to 9.10.1
-
34fc50c1
by Ben Gamari at 2025-08-11T13:36:25-04:00
Kill IOPort#
This type is unnecessary, having been superceded by `MVar` and a rework
of WinIO's blocking logic.
See #20947.
See https://github.com/haskell/core-libraries-committee/issues/213.
-
56b32c5a
by sheaf at 2025-08-12T10:00:19-04:00
Improve deep subsumption
This commit improves the DeepSubsumption sub-typing implementation
in GHC.Tc.Utils.Unify.tc_sub_type_deep by being less eager to fall back
to unification.
For example, we now are properly able to prove the subtyping relationship
((∀ a. a->a) -> Int) -> Bool <= β[tau] Bool
for an unfilled metavariable β. In this case (with an AppTy on the right),
we used to fall back to unification. No longer: now, given that the LHS
is a FunTy and that the RHS is a deep rho type (does not need any instantiation),
we try to make the RHS into a FunTy, viz.
β := (->) γ
We can then continue using covariance & contravariance of the function
arrow, which allows us to prove the subtyping relationship, instead of
trying to unify which would cause us to error out with:
Couldn't match expected type ‘β’ with actual type ‘(->) ((∀ a. a -> a) -> Int)
See Note [FunTy vs non-FunTy case in tc_sub_type_deep] in GHC.Tc.Utils.Unify.
The other main improvement in this patch concerns type inference.
The main subsumption logic happens (before & after this patch) in
GHC.Tc.Gen.App.checkResultTy. However, before this patch, all of the
DeepSubsumption logic only kicked in in 'check' mode, not in 'infer' mode.
This patch adds deep instantiation in the 'infer' mode of checkResultTy
when we are doing deep subsumption, which allows us to accept programs
such as:
f :: Int -> (forall a. a->a)
g :: Int -> Bool -> Bool
test1 b =
case b of
True -> f
False -> g
test2 b =
case b of
True -> g
False -> f
See Note [Deeply instantiate in checkResultTy when inferring].
Finally, we add representation-polymorphism checks to ensure that the
lambda abstractions we introduce when doing subsumption obey the
representation polymorphism invariants of Note [Representation polymorphism invariants]
in GHC.Core. See Note [FunTy vs FunTy case in tc_sub_type_deep].
This is accompanied by a courtesy change to `(<.>) :: HsWrapper -> HsWrapper -> HsWrapper`,
adding the equation:
WpCast c1 <.> WpCast c2 = WpCast (c1 `mkTransCo` c2)
This is useful because mkWpFun does not introduce an eta-expansion when
both of the argument & result wrappers are casts; so this change allows
us to avoid introducing lambda abstractions when casts suffice.
Fixes #26225
-
d175aff8
by Sylvain Henry at 2025-08-12T10:01:31-04:00
Add regression test for #18619
-
a3983a26
by Sylvain Henry at 2025-08-12T10:02:20-04:00
RTS: remove some TSAN annotations (#20464)
Use RELAXED_LOAD_ALWAYS macro instead.
-
0434af81
by Ben Gamari at 2025-08-12T10:03:02-04:00
Bump time submodule to 1.15
Also required bumps of Cabal, directory, and hpc.
-
62899117
by Florian Ragwitz at 2025-08-13T21:01:34-04:00
Extend record-selector usage ticking to all binds using a record field
This extends the previous handling of ticking for RecordWildCards and
NamedFieldPuns to all var bindings that involve record selectors.
Note that certain patterns such as `Foo{foo = 42}` will currently not tick the
`foo` selector, as ticking is triggered by `HsVar`s.
Closes #26191.
-
b37b3af7
by Florian Ragwitz at 2025-08-13T21:01:34-04:00
Add release notes for 9.16.1 and move description of latest HPC changes there.
-
a5e4b7d9
by Ben Gamari at 2025-08-13T21:02:18-04:00
rts: Clarify rationale for undefined atomic wrappers
Since c06e3f46d24ef69f3a3d794f5f604cb8c2a40cbc the RTS has declared
various atomic operation wrappers defined by ghc-internal as undefined.
While the rationale for this isn't clear from the commit message, I
believe that this is necessary due to the unregisterised backend.
Specifically, the code generator will reference these symbols when
compiling RTS Cmm sources.
-
50842f83
by Andreas Klebinger at 2025-08-13T21:03:01-04:00
Make unexpected LLVM versions a warning rather than an error.
Typically a newer LLVM version *will* work so erroring out if
a user uses a newer LLVM version is too aggressive.
Fixes #25915
-
c91e2650
by fendor at 2025-08-13T21:03:43-04:00
Store `StackTrace` and `StackSnapshot` in `Backtraces`
Instead of decoding the stack traces when collecting the `Backtraces`,
defer this decoding until actually showing the `Backtraces`.
This allows users to customise how `Backtraces` are displayed by
using a custom implementation of `displayExceptionWithInfo`, overwriting
the default implementation for `Backtraces` (`displayBacktraces`).
-
dee28cdd
by fendor at 2025-08-13T21:03:43-04:00
Allow users to customise the collection of exception annotations
Add a global `CollectExceptionAnnotationMechanism` which determines how
`ExceptionAnnotation`s are collected upon throwing an `Exception`.
This API is exposed via `ghc-experimental`.
By overriding how we collect `Backtraces`, we can control how the
`Backtraces` are displayed to the user by newtyping `Backtraces` and
giving a different instance for `ExceptionAnnotation`.
A concrete use-case for this feature is allowing us to experiment with
alternative stack decoders, without having to modify `base`, which take
additional information from the stack frames.
This commit does not modify how `Backtraces` are currently
collected or displayed.
-
66024722
by fendor at 2025-08-13T21:03:43-04:00
Expose Backtraces internals from ghc-experimental
Additionally, expose the same API `base:Control.Exception.Backtrace`
to make it easier to use as a drop-in replacement.
-
a766286f
by Reed Mullanix at 2025-08-13T21:04:36-04:00
ghc-internal: Fix naturalAndNot for NB/NS case
When the first argument to `naturalAndNot` is larger than a `Word` and the second is `Word`-sized, `naturalAndNot` will truncate the
result:
```
>>> naturalAndNot ((2 ^ 65) .|. (2 ^ 3)) (2 ^ 3)
0
```
In contrast, `naturalAndNot` does not truncate when both arguments are larger than a `Word`, so this appears to be a bug.
Luckily, the fix is pretty easy: we just need to call `bigNatAndNotWord#` instead of truncating.
Fixes #26230
-
3506fa7d
by Simon Hengel at 2025-08-13T21:05:18-04:00
Report -pgms as a deprecated flag
(instead of reporting an unspecific warning)
Before:
on the commandline: warning:
Object splitting was removed in GHC 8.8
After:
on the commandline: warning: [GHC-53692] [-Wdeprecated-flags]
-pgms is deprecated: Object splitting was removed in GHC 8.8
-
51c701fe
by Zubin Duggal at 2025-08-13T21:06:00-04:00
testsuite: Be more permissive when filtering out GNU_PROPERTY_TYPE linker warnings
The warning text is slightly different with ld.bfd.
Fixes #26249
-
dfe6f464
by Simon Hengel at 2025-08-13T21:06:43-04:00
Refactoring: Don't misuse `MCDiagnostic` for lint messages
`MCDiagnostic` is meant to be used for compiler diagnostics.
Any code that creates `MCDiagnostic` directly, without going through
`GHC.Driver.Errors.printMessage`, side steps `-fdiagnostics-as-json`
(see e.g. !14475, !14492 !14548).
To avoid this in the future I want to control more narrowly who creates
`MCDiagnostic` (see #24113).
Some parts of the compiler use `MCDiagnostic` purely for formatting
purposes, without creating any real compiler diagnostics. This change
introduces a helper function, `formatDiagnostic`, that can be used in
such cases instead of constructing `MCDiagnostic`.
-
a8b2fbae
by Teo Camarasu at 2025-08-13T21:07:24-04:00
rts: ensure MessageBlackHole.link is always a valid closure
We turn a MessageBlackHole into an StgInd in wakeBlockingQueue().
Therefore it's important that the link field, which becomes the
indirection field, always points to a valid closure.
It's unclear whether it's currently possible for the previous behaviour
to lead to a crash, but it's good to be consistent about this invariant nonetheless.
Co-authored-by: Andreas Klebinger <klebinger.andreas@gmx.at>
-
4021181e
by Teo Camarasu at 2025-08-13T21:07:24-04:00
rts: spin if we see a WHITEHOLE in messageBlackHole
When a BLACKHOLE gets cancelled in raiseAsync, we indirect to a THUNK.
GC can then shortcut this, replacing our BLACKHOLE with a fresh THUNK.
This THUNK is not guaranteed to have a valid indirectee field.
If at the same time, a message intended for the previous BLACKHOLE is
processed and concurrently we BLACKHOLE the THUNK, thus temporarily
turning it into a WHITEHOLE, we can get a segfault, since we look at the
undefined indirectee field of the THUNK
The fix is simple: spin if we see a WHITEHOLE, and it will soon be
replaced with a valid BLACKHOLE.
Resolves #26205
-
1107af89
by Oleg Grenrus at 2025-08-13T21:08:06-04:00
Allow defining HasField instances for naughty fields
Resolves #26295
... as HasField solver doesn't solve for fields with "naughty"
selectors, we could as well allow defining HasField instances for these
fields.
-
020e7587
by Sylvain Henry at 2025-08-13T21:09:00-04:00
Fix Data.List unqualified import warning
-
fd811ded
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Make injecting implicit bindings into its own pass
Previously we were injecting "impliicit bindings" (data constructor
worker and wrappers etc)
- both at the end of CoreTidy,
- and at the start of CorePrep
This is unpleasant and confusing. This patch puts it it its own pass,
addImplicitBinds, which runs between the two.
The function `GHC.CoreToStg.AddImplicitBinds.addImplicitBinds` now takes /all/
TyCons, not just the ones for algebraic data types. That change ripples
through to
- corePrepPgm
- doCodeGen
- byteCodeGen
All take [TyCon] which includes all TyCons
-
9bd7fcc5
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Implement unary classes
The big change is described exhaustively in
Note [Unary class magic] in GHC.Core.TyCon
Other changes
* We never unbox class dictionaries in worker/wrapper. This has been true for some
time now, but the logic is now centralised in functions in
GHC.Core.Opt.WorkWrap.Utils, namely `canUnboxTyCon`, and `canUnboxArg`
See Note [Do not unbox class dictionaries] in GHC.Core.Opt.WorkWrap.Utils.
* Refactored the `notWorthFloating` logic in GHc.Core.Opt.SetLevels.
I can't remember if I actually changed any behaviour here, but if so it's
only in a corner cases.
* Fixed a bug in `GHC.Core.TyCon.isEnumerationTyCon`, which was wrongly returning
True for (##).
* Remove redundant Role argument to `liftCoSubstWithEx`. It was always
Representational.
* I refactored evidence generation in the constraint solver:
* Made GHC.Tc.Types.Evidence contain better abstactions for evidence
generation.
* I deleted the file `GHC.Tc.Types.EvTerm` and merged its (small) contents
elsewhere. It wasn't paying its way.
* Made evidence for implicit parameters go via a proper abstraction.
* Fix inlineBoringOk; see (IB6) in Note [inlineBoringOk]
This fixes a slowdown in `countdownEffectfulDynLocal`
in the `effectful` library.
Smaller things
* Rename `isDataTyCon` to `isBoxedDataTyCon`.
* GHC.Core.Corecion.liftCoSubstWithEx was only called with Representational role,
so I baked that into the function and removed the argument.
* Get rid of `GHC.Core.TyCon.tyConSingleAlgDataCon_maybe` in favour of calling
`not isNewTyCon` at the call sites; more explicit.
* Refatored `GHC.Core.TyCon.isInjectiveTyCon`; but I don't think I changed its
behaviour
* Moved `decomposeIPPred` to GHC.Core.Predicate
Compile time performance changes:
geo. mean +0.1%
minimum -6.8%
maximum +14.4%
The +14% one is in T21839c, where it seems that a bit more inlining
is taking place. That seems acceptable; and the average change is small
Metric Decrease:
LargeRecord
T12227
T12707
T16577
T21839r
T5642
Metric Increase:
T15164
T21839c
T3294
T5321FD
T5321Fun
WWRec
-
b4075d71
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Slight improvement to pre/postInlineUnconditionally
Avoids an extra simplifier iteration
-
9e443596
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Fix a long-standing assertion error in normSplitTyConApp_maybe
-
91310ad0
by Simon Peyton Jones at 2025-08-14T17:56:47-04:00
Add comment to coercion optimiser
-
5b841d82
by Teo Camarasu at 2025-08-14T17:57:56-04:00
template-haskell: move some identifiers from ghc-internal to template-haskell
These identifiers are not used internally by the compiler. Therefore we
have no reason for them to be in ghc-internal.
By moving them to template-haskell, we benefit from it being easier to
change them and we avoid having to build them in stage0.
Resolves #26048
-
33e2c7e5
by Teo Camarasu at 2025-08-14T17:57:56-04:00
template-haskell: transfer $infix note to public module
This Haddock note should be in the public facing module
-
2a411fc4
by Sylvain Henry at 2025-08-14T17:59:09-04:00
JS: export HEAP8 symbol (#26290)
Newer Emscripten requires this.
-
248f78ca
by Ben Gamari at 2025-08-14T17:59:51-04:00
users-guide: Drop the THREAD_RUNNABLE event
As of f361281c89fbce42865d8b8b27b0957205366186 it is no longer emitted.
-
706d33e3
by Recursion Ninja at 2025-08-15T04:12:12-04:00
Resolving issues #20645 and #26109
Correctly sign extending and casting smaller bit width types for LLVM operations:
- bitReverse8#
- bitReverse16#
- bitReverse32#
- byteSwap16#
- byteSwap32#
- pdep8#
- pdep16#
- pext8#
- pext16#
-
1cdc6f46
by Cheng Shao at 2025-08-15T04:12:56-04:00
hadrian: enforce have_llvm=False for wasm32/js
This patch fixes hadrian to always pass have_llvm=False to the
testsuite driver for wasm32/js targets. These targets don't really
support the LLVM backend, and the optllvm test way doesn't work. We
used to special-case wasm32/js to avoid auto-adding optllvm way in
testsuite/config/ghc, but this is still problematic if someone writes
a new LLVM-related test and uses something like when(have_llvm(),
extra_ways(["optllvm"])). So better just enforce have_llvm=False for
these targets here.
-
ca03226d
by Ben Gamari at 2025-08-18T13:43:20+00:00
configure: Allow use of LLVM 20
-
783cd7d6
by Cheng Shao at 2025-08-18T20:13:14-04:00
compiler: use `UniqMap` instead of `Map` for `BCEnv` in bytecode compiler
The bytecode compiler maintains a `BCEnv` which was previously `Map Id
StackDepth`. Given `Id` is `Uniquable`, we might as well use `UniqMap`
here as a more efficient data structure, hence this patch.
Co-authored-by: Codex <codex@openai.com>
-
58e46da9
by fendor at 2025-08-18T20:13:56-04:00
rts: Strip lower three bits when hashing Word instead of lower eight bits
-
45dbfa23
by Cheng Shao at 2025-08-18T20:14:37-04:00
libffi: update to 3.5.2
Bumps libffi submodule.
-
54be78ef
by Ben Gamari at 2025-08-19T16:28:05-04:00
testsuite: Fix T20006b
This test is supposed to fail for non-threaded ways yet it
was previously marked as only failing in `normal`.
Fix this.
-
f4bac607
by Simon Peyton Jones at 2025-08-19T16:28:47-04:00
Take yet more care with reporting redundant constraints
This small patch fixes #25992, which relates to reporting redundant
constraints on default-method declarations.
See (TRC5) in Note [Tracking redundant constraints]
-
ab130fec
by fendor at 2025-08-19T16:29:29-04:00
Bump dependencies of hadrian-bootstrap-gen to use GHC 9.6.7
-
6d02ac6f
by fendor at 2025-08-19T16:29:29-04:00
Bump required GHC version for test-bootstrap jobs to 9.10.1
Include test-bootstrap job for GHC 9.12.2.
Update hadrian bootstrap plans use GHC 9.10 and 9.12
Remove older GHC bootstrap configurations.
We require at least GHC 9.10.1 to build GHC.
Adds plans for:
* 9.10.1
* 9.10.2
* 9.12.1
* 9.12.2
-
9e857171
by Brandon Chinn at 2025-08-20T11:47:46-04:00
Don't warn unused-imports with used generated imports
Fixes #21730
* The old notion of "implicit" import has been renamed to "generated". See Note [Generated imports] in GHC.Hs.ImpExp.
* ImportMap now keeps track of generated and user-written imports separately. This avoids the fake SrcSpan we used to give the implicit Prelude import, and the hack that went with it.
* -ddump-minimal-imports now considers generated imports (but still only
warns on + prints user-written imports)
* bestImport considers generated imports to take priority over user-written imports.
-
9fb3bad4
by Ben Gamari at 2025-08-20T11:48:31-04:00
mailmap: Use ben@well-typed.com more liberally
Nearly all of this work was done while working for Well-Typed.
-
774fec37
by Ben Gamari at 2025-08-20T11:49:15-04:00
Add primop to annotate the call stack with arbitrary data
We introduce a new primop `annotateStack#` which allows us to push
arbitrary data onto the call-stack.
This allows us to extract the data later when decoding the stack, for
example when an exception is thrown, showing more information to the
user without having to annotate the full call-stack with `HasCallStack`
constraints.
A new stack frame value is introduced `AnnFrame`, which consists of
nothing but a generic payload.
The primop has a small wrapper API that allows users to annotate their
call-stack in programs.
There is a pure API and an IO-based one. The former is a little bit
dubious, as it affects the evaluation of a program, so use with care.
The latter is "safe", as it doesn't change the evaluation of the
program.
The stack annotation mechanism is similarly implemented to the
`ExceptionAnnotation` and `Exception`, there is a typeclass to indicate
something can be pushed onto the call-stack and all values are wrapped
in the existential `SomeStackAnnotation`, which recover the type of the
annotation payload.
There is currently no builtin way to show the stack annotations when
`Backtraces` are displayed (i.e., when showing stack traces to the user),
which we will address in a follow-up MR.
-------------------------
Metric Increase:
ghc_experimental_so
-------------------------
We increase the size of the package, so this is not unreasonable.
Co-Authored-By: fendor <fendor@posteo.de>
Co-Authored-By: Ben Gamari <bgamari.foss@gmail.com>
-
fdfa3892
by Ben Gamari at 2025-08-20T11:49:57-04:00
testsuite: Add regression test for #24606
-
39b2e382
by Cheng Shao at 2025-08-20T11:50:40-04:00
compiler: only use `Name` instead of `Id` in `SptEntry`
As a part of #26298, this patch refactors `SptEntry` to only carry a
`Name` instead of `Id`: we do not care about extra information like
caffyness or type at all in any static pointer related codegen logic.
This is necessary to make `SptEntry` serializable, as a part of the
grand plan of serializable bytecode.
Co-authored-by: Codex <codex@openai.com>
-
276f8ea8
by Vekhir -- at 2025-08-20T11:51:35-04:00
Bump Cabal dependency
-
0b9c7437
by Zubin Duggal at 2025-08-20T11:52:18-04:00
ci: Teach ci.sh to fetch FreeBSD artifacts from ghcup unofficial bindists and bootstrap compiler on FreeBSD to 9.10.1
Also refactor fetch_ghc logic in ci.sh, renaming the GHC_VERSION enviorment configuration variable to FETCH_GHC_VERSION,
making it clear that it is intended for use on platforms like Windows and FreeBSD where we don't want to use the GHC
excecutable from the platform environment and instead need to download and install GHC-$FETCH_GHC_VERSION from a release
bindist.
Fixes #26296
-
b2914797
by Cheng Shao at 2025-08-20T11:53:00-04:00
driver: use UniqSet for hiddenModules in DynFlags/FinderOpts
This patch replaces Set ModuleName with UniqSet ModuleName in
DynFlags.hiddenModules and FinderOpts.finder_hiddenModules for
improved efficiency.
Co-authored-by: Codex <codex@openai.com>
-
0335d899
by Cheng Shao at 2025-08-20T11:53:00-04:00
driver: use UniqMap ModuleName in the finder
This patch replaces Map ModuleName with UniqMap ModuleName in the
finder for improved efficiency.
Co-authored-by: Codex <codex@openai.com>
-
91f4faaa
by Cheng Shao at 2025-08-20T11:53:43-04:00
configure: check python3 version and require minimal 3.7
Since !9515, the testsuite driver requires python3 version to be at
least 3.7, though this has never been checked by configure logic. This
patch implements the version check. Fixes #23234.
Co-authored-by: Codex <codex@openai.com>
-
df4ee9b4
by Cheng Shao at 2025-08-20T11:54:25-04:00
compiler: use zero cost coerce in GHC.CmmToAsm.CFG.loopInfo
This patch refactors GHC.CmmToAsm.CFG.loopInfo to use zero cost coerce
and thus addresses the TODO. For coerce to work, constructors of
Label/LabelMap/LabelSet from GHC.Cmm.Dataflow.Label are exposed,
though I believe it's a worthy tradeoff to avoid unnecessary runtime
cost without using unsafeCoerce, since the latter could be a landmine
for future refactoring.
Co-authored-by: Codex <codex@openai.com>
-
ccda188d
by Simon Peyton Jones at 2025-08-20T11:55:07-04:00
Start with empty inerts in shortcut solving
When short-cut solving we were starting with an inert set that had
unsolved Wanteds. This caused an infinite loop (#26314), because a
typechecker plugin kept being given that unsolved Wanted.
It's better just to start with an empty inert set
-
c8882ed7
by Ben Gamari at 2025-08-20T11:55:49-04:00
configure: Bump minimal bootstrap GHC version to 9.8
-
f0a19d74
by fendor at 2025-08-20T19:55:00-04:00
Remove deprecated functions from the ghci package
-
ebeb991b
by fendor at 2025-08-20T19:55:00-04:00
base: Remove unstable heap representation details from GHC.Exts
-
e368e247
by Rodrigo Mesquita at 2025-08-20T19:55:42-04:00
bytecode: Use 32bits for breakpoint index
Fixes #26325
-
42724462
by Simon Hengel at 2025-08-21T17:52:11-04:00
Serialize wired-in names as external names when creating HIE files
Note that the domain of de-serialized names stays the same.
Specifically, for known-key names, before `lookupKnownKeyName` was used,
while now this is handled by `lookupOrigNameCache` which captures the
same range provided that the OrigNameCache has been initialized with
`knownKeyNames` (which is the case by default).
(fixes #26238)
-
6a43f8ec
by Cheng Shao at 2025-08-21T17:52:52-04:00
compiler: fix closure C type in SPT init code
This patch fixes the closure C type in SPT init code to StgClosure,
instead of the previously incorrect StgPtr. Having an incorrect C type
makes SPT init code not compatible with other foreign stub generation
logic, which may also emit their own extern declarations for the same
closure symbols and thus will clash with the incorrect prototypes in
SPT init code.
-
5b5d9d47
by Ben Gamari at 2025-08-25T14:29:35-04:00
Revert "STM: don't create a transaction in the rhs of catchRetry# (#26028)"
This reverts commit 0a5836891ca29836a24c306d2a364c2e4b5377fd
-
10f06163
by Cheng Shao at 2025-08-25T14:30:16-04:00
wasm: ensure setKeepCAFs() is called in ghci
This patch is a critical bugfix for #26106, see comment and linked
issue for details.
-
bedc1004
by Cheng Shao at 2025-08-26T09:31:18-04:00
compiler: use zero cost coerce in hoopl setElems/mapToList
This patch is a follow-up of !14680 and changes setElems/mapToList in
GHC/Cmm/Dataflow/Label to use coerce instead of mapping mkHooplLabel
over the keys.
-
13250d97
by Ryan Scott at 2025-08-26T09:31:59-04:00
Reject infix promoted data constructors without DataKinds
In the rename, make sure to apply the same `DataKinds` checks for both
`HsTyVar` (for prefix promoted data constructors) and `HsOpTy` (for infix
promoted data constructors) alike.
Fixes #26318.
-
37655c46
by Teo Camarasu at 2025-08-26T15:24:51-04:00
tests: disable T22859 under LLVM
This test was failing under the LLVM backend since the allocations
differ from the NCG.
Resolves #26282
-
2cbba9d6
by Teo Camarasu at 2025-08-26T15:25:33-04:00
base-exports: update version numbers
As the version of the compiler has been bumped, a lot of the embedded
version numbers will need to be updated if we ever run this test with
`--test-accept` so let's just update them now, and keep future diffs
clean.
-
f9f2ffcf
by Alexandre Esteves at 2025-08-27T07:19:14-04:00
Import new name for 'utimbuf' on windows to fix #26337
Fixes an `-Wincompatible-pointer-types` instance that turns into an error on
recent toolchains and surfaced as such on nixpkgs when doing linux->ucrt cross.
This long-standing warning has been present at least since 9.4:
```
C:\GitLabRunner\builds\0\1709189\tmp\ghc16652_0\ghc_4.c:26:115: error:
warning: incompatible pointer types passing 'struct utimbuf *' to parameter of type 'struct _utimbuf *' [-Wincompatible-pointer-types]
|
26 | HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);}
| ^
HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);}
^~
C:\GitLabRunner\builds\0\1709189\_build\stage0\lib\..\..\mingw\x86_64-w64-mingw32\include\sys\utime.h:109:72: error:
note: passing argument to parameter '_Utimbuf' here
|
109 | __CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) {
| ^
__CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) {
```
-
ae89f000
by Hassan Al-Awwadi at 2025-08-27T07:19:56-04:00
Adds the fucnction addDependentDirectory to Q, resolving issue #26148.
This function adds a new directory to the list of things a module depends upon. That means that when the contents of the directory change, the recompilation checker will notice this and the module will be recompiled. Documentation has also been added for addDependentFunction and addDependentDirectory in the user guide.
-
00478944
by Simon Peyton Jones at 2025-08-27T16:48:30+01:00
Comments only
-
a7884589
by Simon Peyton Jones at 2025-08-28T11:08:23+01:00
Type-family occurs check in unification
The occurs check in `GHC.Core.Unify.uVarOrFam` was inadequate in dealing
with type families.
Better now. See Note [The occurs check in the Core unifier].
As I did this I realised that the whole apartness thing is trickier than I
thought: see the new Note [Shortcomings of the apartness test]
-
8adfc222
by sheaf at 2025-08-28T19:47:17-04:00
Fix orientation in HsWrapper composition (<.>)
This commit fixes the order in which WpCast HsWrappers are composed,
fixing a bug introduced in commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1.
Fixes #26350
-
eb2ab1e2
by Oleg Grenrus at 2025-08-29T11:00:53-04:00
Generalise thNameToGhcName by adding HasHscEnv
There were multiple single monad-specific `getHscEnv` across codebase.
HasHscEnv is modelled on HasDynFlags.
My first idea was to simply add thNameToGhcNameHsc and
thNameToGhcNameTc, but those would been exactly the same
as thNameToGhcName already.
Also add an usage example to thNameToGhcName and mention that it's
recommended way of looking up names in GHC plugins
-
2d575a7f
by fendor at 2025-08-29T11:01:36-04:00
configure: Bump minimal bootstrap GHC version to 9.10
-
716274a5
by Simon Peyton Jones at 2025-08-29T17:27:12-04:00
Fix deep subsumption again
This commit fixed #26255:
commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1
Author: sheaf <sam.derbyshire@gmail.com>
Date: Mon Aug 11 15:50:47 2025 +0200
Improve deep subsumption
This commit improves the DeepSubsumption sub-typing implementation
in GHC.Tc.Utils.Unify.tc_sub_type_deep by being less eager to fall back
to unification.
But alas it still wasn't quite right for view patterns: #26331
This MR does a generalisation to fix it. A bit of a sledgehammer to crack
a nut, but nice.
* Add a field `ir_inst :: InferInstFlag` to `InferResult`, where
```
data InferInstFlag = IIF_Sigma | IIF_ShallowRho | IIF_DeepRho
```
* The flag says exactly how much `fillInferResult` should instantiate
before filling the hole.
* We can also use this to replace the previous very ad-hoc `tcInferSigma`
that was used to implement GHCi's `:type` command.
-
27206c5e
by sheaf at 2025-08-29T17:28:14-04:00
Back-compat for TH SpecialiseP data-con of Pragma
This commit improves the backwards-compatibility story for the
SpecialiseP constructor of the Template Haskell 'Pragma' datatype.
Instead of keeping the constructor but deprecating it, this commit makes
it into a bundled pattern synonym of the Pragma datatype. We no longer
deprecate it; it's useful for handling old-form specialise pragmas.
-
26dbcf61
by fendor at 2025-08-30T05:10:08-04:00
Move stack decoding logic from ghc-heap to ghc-internal
The stack decoding logic in `ghc-heap` is more sophisticated than the one
currently employed in `CloneStack`. We want to use the stack decoding
implementation from `ghc-heap` in `base`.
We cannot simply depend on `ghc-heap` in `base` due do bootstrapping
issues.
Thus, we move the code that is necessary to implement stack decoding to
`ghc-internal`. This is the right location, as we don't want to add a
new API to `base`.
Moving the stack decoding logic and re-exposing it in ghc-heap is
insufficient, though, as we have a dependency cycle between.
* ghc-heap depends on stage1:ghc-internal
* stage0:ghc depends on stage0:ghc-heap
To fix this, we remove ghc-heap from the set of `stage0` dependencies.
This is not entirely straight-forward, as a couple of boot dependencies,
such as `ghci` depend on `ghc-heap`.
Luckily, the boot compiler of GHC is now >=9.10, so we can migrate `ghci`
to use `ghc-internal` instead of `ghc-heap`, which already exports the
relevant modules.
However, we cannot 100% remove ghc's dependency on `ghc-heap`, since
when we compile `stage0:ghc`, `stage1:ghc-internal` is not yet
available.
Thus, when we compile with the boot-compiler, we still depend on an
older version of `ghc-heap`, and only use the modules from `ghc-internal`,
if the `ghc-internal` version is recent enough.
-------------------------
Metric Increase:
T24602_perf_size
T25046_perf_size_gzip
T25046_perf_size_unicode
T25046_perf_size_unicode_gzip
size_hello_artifact
size_hello_artifact_gzip
size_hello_unicode
size_hello_unicode_gzip
-------------------------
These metric increases are unfortunate, they are most likely caused by
the larger (literally in terms of lines of code) stack decoder implementation
that are now linked into hello-word binaries.
On linux, it is almost a 10% increase, which is considerable.
-
bd80bb70
by fendor at 2025-08-30T05:10:08-04:00
Implement `decode` in terms of `decodeStackWithIpe`
Uses the more efficient stack decoder implementation.
-
24441165
by fendor at 2025-08-30T05:10:08-04:00
Remove stg_decodeStackzh
-
fb9cc882
by Simon Peyton Jones at 2025-08-30T05:10:51-04:00
Fix a long standing bug in the coercion optimiser
We were mis-optimising ForAllCo, leading to #26345
Part of the poblem was the tricky tower of abstractions leading to
the dreadful
GHC.Core.TyCo.Subst.substForAllCoTyVarBndrUsing
This function was serving two masters: regular substitution, but also
coercion optimsation. So tricky was it that it did so wrong.
In this MR I locate all the fancy footwork for coercion optimisation
in GHC.Core.Coercion.Opt, where it belongs. That leaves substitution
free to be much simpler.
-
6c78de2d
by Sylvain Henry at 2025-09-01T08:46:19-04:00
Driver: substitute virtual Prim module in --make mode too
When we build ghc-internal with --make (e.g. with cabal-install), we
need to be careful to substitute the virtual interface file for
GHC.Internal.Prim:
- after code generation (we generate code for an empty module, so we get
an empty interface)
- when we try to reload its .hi file
-
26e0db16
by fendor at 2025-09-01T08:47:01-04:00
Expose Stack Annotation frames in IPE backtraces by default
When decoding the Haskell-native call stack and displaying the IPE information
for the stack frames, we print the `StackAnnotation` of the `AnnFrame` by default.
This means, when an exception is thrown, any intermediate stack annotations will
be displayed in the `IPE Backtrace`.
Example backtrace:
```
Exception: ghc-internal:GHC.Internal.Exception.ErrorCall:
Oh no!
IPE backtrace:
annotateCallStackIO, called at app/Main.hs:48:10 in backtrace-0.1.0.0-inplace-server:Main
annotateCallStackIO, called at app/Main.hs:46:13 in backtrace-0.1.0.0-inplace-server:Main
Main.handler (app/Main.hs:(46,1)-(49,30))
Main.liftIO (src/Servant/Server/Internal/Handler.hs:30:36-42)
Servant.Server.Internal.Delayed.runHandler' (src/Servant/Server/Internal/Handler.hs:27:31-41)
Control.Monad.Trans.Resource.runResourceT (./Control/Monad/Trans/Resource.hs:(192,14)-(197,18))
Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:195:20-22)
Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:(195,5)-(203,31))
Network.Wai.Handler.Warp.HTTP1.http1server.loop (./Network/Wai/Handler/Warp/HTTP1.hs:(141,9)-(157,42))
HasCallStack backtrace:
error, called at app/Main.hs:48:32 in backtrace-0.1.0.0-inplace-server:Main
```
The first two entries have been added by `annotateCallStackIO`, defined in `annotateCallStackIO`.
-
a1567efd
by Sylvain Henry at 2025-09-01T23:01:35-04:00
RTS: rely less on Hadrian for flag setting (#25843)
Hadrian used to pass -Dfoo command-line flags directly to build the rts.
We can replace most of these flags with CPP based on cabal flags.
It makes building boot libraries with cabal-install simpler (cf #25843).
-
ca5b0283
by Sergey Vinokurov at 2025-09-01T23:02:23-04:00
Remove unnecessary irrefutable patterns from Bifunctor instances for tuples
Implementation of https://github.com/haskell/core-libraries-committee/issues/339
Metric Decrease:
mhu-perf
-
2da84b7a
by sheaf at 2025-09-01T23:03:23-04:00
Only use active rules when simplifying rule RHSs
When we are simplifying the RHS of a rule, we make sure to only apply
rewrites from rules that are active throughout the original rule's
range of active phases.
For example, if a rule is always active, we only fire rules that are
themselves always active when simplifying the RHS. Ditto for inline
activations.
This is achieved by setting the simplifier phase to a range of phases,
using the new SimplPhaseRange constructor. Then:
1. When simplifying the RHS of a rule, or of a stable unfolding,
we set the simplifier phase to a range of phases, computed from
the activation of the RULE/unfolding activation, using the
function 'phaseFromActivation'.
The details are explained in Note [What is active in the RHS of a RULE?]
in GHC.Core.Opt.Simplify.Utils.
2. The activation check for other rules and inlinings is then:
does the activation of the other rule/inlining cover the whole
phase range set in sm_phase? This continues to use the 'isActive'
function, which now accounts for phase ranges.
On the way, this commit also moves the exact-print SourceText annotation
from the Activation datatype to the ActivationAnn type. This keeps the
main Activation datatype free of any extra cruft.
Fixes #26323
-
79816cc4
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
cleanup: Move dehydrateCgBreakInfo to Stg2Bc
This no longer has anything to do with Core.
-
53da94ff
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
rts/Disassembler: Fix spacing of BRK_FUN
-
08c0cf85
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
debugger: Fix bciPtr in Step-out
We need to use `BCO_NEXT` to move bciPtr to ix=1, because ix=0 points to
the instruction itself!
I do not understand how this didn't crash before.
-
e7e021fa
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
debugger: Allow BRK_FUNs to head case continuation BCOs
When we start executing a BCO, we may want to yield to the scheduler:
this may be triggered by a heap/stack check, context switch, or a
breakpoint. To yield, we need to put the stack in a state such that
when execution is resumed we are back to where we yielded from.
Previously, a BKR_FUN could only head a function BCO because we only
knew how to construct a valid stack for yielding from one -- simply add
`apply_interp_info` + the BCO to resume executing. This is valid because
the stack at the start of run_BCO is headed by that BCO's arguments.
However, in case continuation BCOs (as per Note [Case continuation BCOs]),
we couldn't easily reconstruct a valid stack that could be resumed
because we dropped too soon the stack frames regarding the value
returned (stg_ret) and received (stg_ctoi) by that continuation.
This is especially tricky because of the variable type and size return
frames (e.g. pointer ret_p/ctoi_R1p vs a tuple ret_t/ctoi_t2).
The trick to being able to yield from a BRK_FUN at the start of a case
cont BCO is to stop removing the ret frame headers eagerly and instead
keep them until the BCO starts executing. The new layout at the start of
a case cont. BCO is described by the new Note [Stack layout when entering run_BCO].
Now, we keep the ret_* and ctoi_* frames when entering run_BCO.
A BRK_FUN is then executed if found, and the stack is yielded as-is with
the preserved ret and ctoi frames.
Then, a case cont BCO's instructions always SLIDE off the headers of the
ret and ctoi frames, in StgToByteCode.doCase, turning a stack like
| .... |
+---------------+
| fv2 |
+---------------+
| fv1 |
+---------------+
| BCO |
+---------------+
| stg_ctoi_ret_ |
+---------------+
| retval |
+---------------+
| stg_ret_..... |
+---------------+
into
| .... |
+---------------+
| fv2 |
+---------------+
| fv1 |
+---------------+
| retval |
+---------------+
for the remainder of the BCO.
Moreover, this more uniform approach of keeping the ret and ctoi frames
means we need less ad-hoc logic concerning the variable size of
ret_tuple vs ret_p/np frames in the code generator and interpreter:
Always keep the return to cont. stack intact at the start of run_BCO,
and the statically generated instructions will take care of adjusting
it.
Unlocks BRK_FUNs at the start of case cont. BCOs which will enable a
better user-facing step-out (#26042) which is free of the bugs the
current BRK_ALTS implementation suffers from (namely, using BRK_FUN
rather than BRK_ALTS in a case cont. means we'll never accidentally end
up in a breakpoint "deeper" than the continuation, because we stop at
the case cont itself rather than on the first breakpoint we evaluate
after it).
-
ade3c1e6
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
BRK_FUN with InternalBreakLocs for code-generation time breakpoints
At the start of a case continuation BCO, place a BRK_FUN.
This BRK_FUN uses the new "internal breakpoint location" -- allowing us
to come up with a valid source location for this breakpoint that is not associated with a source-level tick.
For case continuation BCOs, we use the last tick seen before it as the
source location. The reasoning is described in Note [Debugger: Stepout internal break locs].
Note how T26042c, which was broken because it displayed the incorrect
behavior of the previous step out when we'd end up at a deeper level
than the one from which we initiated step-out, is now fixed.
As of this commit, BRK_ALTS is now dead code and is thus dropped.
Note [Debugger: Stepout internal break locs]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Step-out tells the interpreter to run until the current function
returns to where it was called from, and stop there.
This is achieved by enabling the BRK_FUN found on the first RET_BCO
frame on the stack (See [Note Debugger: Step-out]).
Case continuation BCOs (which select an alternative branch) must
therefore be headed by a BRK_FUN. An example:
f x = case g x of <--- end up here
1 -> ...
2 -> ...
g y = ... <--- step out from here
- `g` will return a value to the case continuation BCO in `f`
- The case continuation BCO will receive the value returned from g
- Match on it and push the alternative continuation for that branch
- And then enter that alternative.
If we step-out of `g`, the first RET_BCO on the stack is the case
continuation of `f` -- execution should stop at its start, before
selecting an alternative. (One might ask, "why not enable the breakpoint
in the alternative instead?", because the alternative continuation is
only pushed to the stack *after* it is selected by the case cont. BCO)
However, the case cont. BCO is not associated with any source-level
tick, it is merely the glue code which selects alternatives which do
have source level ticks. Therefore, we have to come up at code
generation time with a breakpoint location ('InternalBreakLoc') to
display to the user when it is stopped there.
Our solution is to use the last tick seen just before reaching the case
continuation. This is robust because a case continuation will thus
always have a relevant breakpoint location:
- The source location will be the last source-relevant expression
executed before the continuation is pushed
- So the source location will point to the thing you've just stepped
out of
- Doing :step-local from there will put you on the selected
alternative (which at the source level may also be the e.g. next
line in a do-block)
Examples, using angle brackets (<<...>>) to denote the breakpoint span:
f x = case <<g x>> {- step in here -} of
1 -> ...
2 -> ...>
g y = <<...>> <--- step out from here
...
f x = <<case g x of <--- end up here, whole case highlighted
1 -> ...
2 -> ...>>
doing :step-local ...
f x = case g x of
1 -> <<...>> <--- stop in the alternative
2 -> ...
A second example based on T26042d2, where the source is a do-block IO
action, optimised to a chain of `case expressions`.
main = do
putStrLn "hello1"
<<f>> <--- step-in here
putStrLn "hello3"
putStrLn "hello4"
f = do
<<putStrLn "hello2.1">> <--- step-out from here
putStrLn "hello2.2"
...
main = do
putStrLn "hello1"
<<f>> <--- end up here again, the previously executed expression
putStrLn "hello3"
putStrLn "hello4"
doing step/step-local ...
main = do
putStrLn "hello1"
f
<<putStrLn "hello3">> <--- straight to the next line
putStrLn "hello4"
Finishes #26042
-
c66910c0
by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00
debugger: Re-use the last BreakpointId whole in step-out
Previously, to come up with a location to stop at for `:stepout`, we
would store the location of the last BreakpointId surrounding the
continuation, as described by Note [Debugger: Stepout internal break locs].
However, re-using just the location from the last source breakpoint
isn't sufficient to provide the necessary information in the break
location. Specifically, it wouldn't bind any variables at that location.
Really, there is no reason not to re-use the last breakpoint wholesale,
and re-use all the information we had there. Step-out should behave just
as if we had stopped at the call, but s.t. continuing will not
re-execute the call.
This commit updates the CgBreakInfo to always store a BreakpointId, be
it the original one or the one we're emulating (for step-out).
It makes variable bindings on :stepout work
-
e4abed7b
by sheaf at 2025-09-02T12:20:40-04:00
Revert accidental changes to hie.yaml
-
003b715b
by meooow25 at 2025-09-02T23:48:51+02:00
Adjust the strictness of Data.List.iterate'
* Don't force the next element in advance when generating a (:).
* Force the first element to WHNF like every other element.
Now every element in the output list is forced to WHNF when the (:)
containing it is forced.
CLC proposal:
https://github.com/haskell/core-libraries-committee/issues/335
-
b2f6aad0
by Simon Hengel at 2025-09-03T04:36:10-04:00
Refactoring: More consistently use logOutput, logInfo, fatalErrorMsg
-
60a16db7
by Rodrigo Mesquita at 2025-09-03T10:55:50+01:00
bytecode: Don't PUSH_L 0; SLIDE 1 1
While looking through bytecode I noticed a quite common unfortunate
pattern:
...
PUSH_L 0
SLIDE 1 1
We do this often by generically constructing a tail call from a function
atom that may be somewhere arbitrary on the stack.
However, for the special case that the function can be found directly on
top of the stack, as part of the arguments, it's plain redundant to push
then slide it.
In this commit we add a small optimisation to the generation of
tailcalls in bytecode. Simply: lookahead for the function in the stack.
If it is the first thing on the stack and it is part of the arguments
which would be dropped as we entered the tail call, then don't push then
slide it.
In a simple example (T26042b), this already produced a drastic
improvement in generated code (left is old, right is with this patch):
```diff
3c3
< 2025-07-29 10:14:02.081277 UTC
---
> 2025-07-29 10:50:36.560949 UTC
160,161c160
< PUSH_L 0
< SLIDE 1 2
---
> SLIDE 1 1
164,165d162
< PUSH_L 0
< SLIDE 1 1
175,176c172
< PUSH_L 0
< SLIDE 1 2
---
> SLIDE 1 1
179,180d174
< PUSH_L 0
< SLIDE 1 1
206,207d199
< PUSH_L 0
< SLIDE 1 1
210,211d201
< PUSH_L 0
< SLIDE 1 1
214,215d203
< PUSH_L 0
< SLIDE 1 1
218,219d205
< PUSH_L 0
< SLIDE 1 1
222,223d207
< PUSH_L 0
< SLIDE 1 1
...
600,601c566
< PUSH_L 0
< SLIDE 1 2
---
> SLIDE 1 1
604,605d568
< PUSH_L 0
< SLIDE 1 1
632,633d594
< PUSH_L 0
< SLIDE 1 1
636,637d596
< PUSH_L 0
< SLIDE 1 1
640,641d598
< PUSH_L 0
< SLIDE 1 1
644,645d600
< PUSH_L 0
< SLIDE 1 1
648,649d602
< PUSH_L 0
< SLIDE 1 1
652,653d604
< PUSH_L 0
< SLIDE 1 1
656,657d606
< PUSH_L 0
< SLIDE 1 1
660,661d608
< PUSH_L 0
< SLIDE 1 1
664,665d610
< PUSH_L 0
< SLIDE 1 1
```
I also compiled lib:Cabal to bytecode and counted the number of bytecode
lines with `find dist-newstyle -name "*.dump-BCOs" -exec wc {} +`:
with unoptimized core:
1190689 lines (before) - 1172891 lines (now)
= 17798 less redundant instructions (-1.5% lines)
with optimized core:
1924818 lines (before) - 1864836 lines (now)
= 59982 less redundant instructions (-3.1% lines)
-
8b2c72c0
by L0neGamer at 2025-09-04T06:32:03-04:00
Add Control.Monad.thenM and Control.Applicative.thenA
-
39e1b7cb
by Teo Camarasu at 2025-09-04T06:32:46-04:00
ghc-internal: invert dependency of GHC.Internal.TH.Syntax on Data.Data
This means that Data.Data no longer blocks building TH.Syntax, which
allows greater parallelism in our builds.
We move the Data.Data.Data instances to Data.Data. Quasi depends on
Data.Data for one of its methods, so,
we split the Quasi/Q, etc definition out of GHC.Internal.TH.Syntax
into its own module. This has the added benefit of splitting up this
quite large module.
Previously TH.Syntax was a bottleneck when compiling ghc-internal. Now
it is less of a bottle-neck and is also slightly quicker to
compile (since it no longer contains these instances) at the cost of
making Data.Data slightly more expensive to compile.
TH.Lift which depends on TH.Syntax can also compile quicker and no
longer blocks ghc-internal finishing to compile.
Resolves #26217
-------------------------
Metric Decrease:
MultiLayerModulesTH_OneShot
T13253
T21839c
T24471
Metric Increase:
T12227
-------------------------
-
bdf82fd2
by Teo Camarasu at 2025-09-04T06:32:46-04:00
compiler: delete unused names in Builtins.Names.TH
returnQ and bindQ are no longer used in the compiler.
There was also a very old comment that referred to them that I have modernized
-
41a448e5
by Ben Gamari at 2025-09-04T19:21:43-04:00
hadrian: Pass lib & include directories to ghc `Setup configure`
-
46bb9a79
by Ben Gamari at 2025-09-04T19:21:44-04:00
rts/IPE: Fix compilation when zstd is enabled
This was broken by the refactoring undertaken in
c80dd91c0bf6ac034f0c592f16c548b9408a8481.
Closes #26312.
-
138a6e34
by sheaf at 2025-09-04T19:22:46-04:00
Make mkCast assertion a bit clearer
This commit changes the assertion message that gets printed when one
calls mkCast with a coercion whose kind does not match the type of the
inner expression. I always found the assertion message a bit confusing,
as it didn't clearly state what exactly was the error.
-
9d626be1
by sheaf at 2025-09-04T19:22:46-04:00
Simplifier/rules: fix mistakes in Notes & comments
-
94b62aa7
by Simon Peyton Jones at 2025-09-08T03:37:14-04:00
Refactor ForAllCo
This is a pure refactor, addressing #26389.
It arranges that the kind coercion in a ForAllCo is a MCoercion, rather
than a plain Coercion, thus removing redundancy in the common case.
See (FC8) in Note [ForAllCo]
It's a nice cleanup.
-
624afa4a
by sheaf at 2025-09-08T03:38:05-04:00
Use tcMkScaledFunTys in matchExpectedFunTys
We should use tcMkScaledFunTys rather than mkScaledFunTys in
GHC.Tc.Utils.Unify.matchExpectedFunTys, as the latter crashes
when the kind of the result type is a bare metavariable.
We know the result is always Type-like, so we don't need scaledFunTys
to try to rediscover that from the kind.
Fixes #26277
-
0975d2b6
by sheaf at 2025-09-08T03:38:54-04:00
Revert "Remove hptAllFamInstances usage during upsweep"
This reverts commit 3bf6720eff5e86e673568e756161e6d6150eb440.
-
0cf34176
by soulomoon at 2025-09-08T03:38:54-04:00
Family consistency checks: add test for #26154
This commit adds the test T26154, to make sure that GHC doesn't crash
when performing type family consistency checks. This test case
was extracted from Agda.
Fixes #26154
-
ba210d98
by Simon Peyton Jones at 2025-09-08T16:26:36+01:00
Report solid equality errors before custom errors
This MR fixes #26255 by
* Reporting solid equality errors like
Int ~ Bool
before "custom type errors". See comments in `report1` in
`reportWanteds`
* Suppressing errors that arise from superclasses of
Wanteds. See (SCE1) in Note [Suppressing confusing errors]
More details in #26255.
-
b6249140
by Simon Peyton Jones at 2025-09-10T10:42:38-04:00
Fix a scoping error in Specialise
This small patch fixes #26329, which triggered a scoping error.
Test is in T21391, with -fpolymorphic-specialisation enabled
-
45305ab8
by sheaf at 2025-09-10T10:43:29-04:00
Make rationalTo{Float,Double} inline in phase 0
We hold off on inlining these until phase 0 to allow constant-folding
rules to fire. However, once we get to phase 0, we should inline them,
e.g. to expose unboxing opportunities.
See CLC proposal #356.
-
0959d4bc
by Andreas Klebinger at 2025-09-10T10:44:12-04:00
Add regression test for #26056
-
dc79593d
by sheaf at 2025-09-10T10:45:01-04:00
Deep subsumption: unify mults without tcEqMult
As seen in #26332, we may well end up with a non-reflexive multiplicity
coercion when doing deep subsumption. We should do the same thing that
we do without deep subsumption: unify the multiplicities normally,
without requiring that the coercion is reflexive (which is what
'tcEqMult' was doing).
Fixes #26332
-
4bfe2269
by sheaf at 2025-09-10T10:45:50-04:00
lint-codes: fixup MSYS drive letter on Windows
This change ensures that System.Directory.listDirectory doesn't trip up
on an MSYS-style path like '/c/Foo' when trying to list all testsuite
stdout/stderr files as required for testing coverage of GHC diagnostic
codes in the testsuite.
Fixes #25178
-
56540775
by Ben Gamari at 2025-09-10T10:46:32-04:00
gitlab-ci: Disable split sections on FreeBSD
Due to #26303.
-
1537784b
by Moritz Angermann at 2025-09-10T10:47:13-04:00
Improve mach-o relocation information
This change adds more information about the symbol and addresses
we try to relocate in the linker. This significantly helps when
deubbging relocation issues reported by users.
-
4e67855b
by Moritz Angermann at 2025-09-10T10:47:54-04:00
test.mk expect GhcLeadingUnderscore, not LeadingUnderscore (in line with the other Ghc prefixed variables.
-
c1cdd265
by Moritz Angermann at 2025-09-10T10:48:35-04:00
testsuite: Fix broken exec_signals_child.c
There is no signal 0. The signal mask is 1-32.
-
99ac335c
by Moritz Angermann at 2025-09-10T10:49:15-04:00
testsuite: clarify Windows/Darwin locale rationale for skipping T6037 T2507 T8959a
-
0e8fa77a
by Moritz Angermann at 2025-09-10T10:49:56-04:00
Skip broken tests on macOS (due to leading underscore not handled properly in the expected output.)
-
28570c59
by Zubin Duggal at 2025-09-10T10:50:37-04:00
docs(sphinx): fix links to reverse flags when using the :ghc-flag:`-fno-<flag>` syntax
This solution is rather hacky and I suspect there is a better way to do this but I don't know
enough about Sphinx to do better.
Fixes #26352
-
d17257ed
by Cheng Shao at 2025-09-10T17:01:27+02:00
rel-eng: update alpine images to 3.22
This patch is a part of #25876 and updates alpine images to 3.22,
while still retaining 3.12 for x86_64 fully_static bindists.
-------------------------
Metric Decrease:
MultiComponentModulesRecomp
-------------------------
-
db3276bb
by Sylvain Henry at 2025-09-11T11:27:28-04:00
T16180: indicate that the stack isn't executable
-
11eeeba7
by Sylvain Henry at 2025-09-11T11:27:28-04:00
Fix some tests (statically linked GHC vs libc)
When GHC is linked statically, the stdout C global variable that GHC uses
isn't shared with the stdout C global variable used by loaded code.
As a consequence, the latter must be explicitly flushed because GHC
won't flush it before exiting.
-
80a07571
by Sylvain Henry at 2025-09-11T11:28:18-04:00
Testsuite: fix debug_rts detection
Running the testsuite without Hadrian should set config.debug_rts
correctly too.
-
62ae97de
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Handle heap allocation failure in I/O primops
The current I/O managers do not use allocateMightFail, but future ones
will. To support this properly we need to be able to return to the
primop with a failure. We simply use a bool return value.
Currently however, we will just throw an exception rather than calling
the GC because that's what all the other primops do too.
For the general issue of primops invoking GC and retrying, see
https://gitlab.haskell.org/ghc/ghc/-/issues/24105
-
cb9093f5
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Move (and rename) scheduleStartSignalHandlers into RtsSignals.h
Previously it was a local helper (static) function in Schedule.c.
Rename it to startPendingSignalHandlers and deifine it as an inline
header function in RtsSignals.h. So it should still be fast.
Each (new style) I/O manager is going to need to do the same, so eliminating
the duplication now makes sense.
-
9736d44a
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Reduce detail in printThreadBlockage I/O blocking cases
The printThreadBlockage is used in debug tracing output.
For the cases BlockedOn{Read,Write,Delay} the output previously included
the fd that was being waited on, and the delay target wake time.
Superficially this sounds useful, but it's clearly not that useful
because it was already wrong for the Win32 non-threaded I/O manager. In
that situation it will print garbage (the async_result pointer, cast to
a fd or a time).
So given that it apparently never mattered that the information was
accurate, then it's hardly a big jump to say it doesn't matter if it is
present at all.
A good reason to remove it is that otherwise we have to make a new
API and a per-I/O manager implementation to fetch the information. And
for some I/O manager implementations, this information is not available.
It is not available in the win32 non-threaded I/O manager. And for some
future Linux ones, there is no need for the fd to be stored, so storing
it would be just extra space used for very little gain.
So the simplest thing is to just remove the detail.
-
bc0f2d5d
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Add TimeoutQueue.{c,h} and corresponding tests
A data structure used to efficiently manage a collection of timeouts.
It is a priority queue based on absolute expiry time. It uses 64bit
high-precision Time for the keys. The values are normal closures which
allows for example using MVars for unblocking.
It is common in many applications for timeouts to be created and then
deleted or altered before they expire. Thus the choice of data structure
for timeouts should support this efficiently. The implementation choice
here is a leftist heap with the extra feature that it supports deleting
arbitrary elements, provided the caller retain a pointer to the element.
While the deleteMin operation takes O(log n) time, as in all heap
structures, the delete operation for arbitrary elements /typically/
takes O(1), and only O(log n) in the worst case. In practice, when
managing thousands of timeouts it can be a factor of 10 faster to delete
a random timeout queue element than to remove the minimum element. This
supports the common use case.
The plan is to use it in some of the RTS-side I/O managers to support
their timer functionality. In this use case the heap value will be an
MVar used for each timeout to unblock waiting threads.
-
d1679c9d
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Add ClosureTable.{c,h} and corresponding tests
A table of pointers to closures on the GC heap with stable indexes.
It provides O(1) alloc, free and lookup. The table can be expanded
using a simple doubling strategy: in which case allocation is typically
O(1) and occasionally O(n) for overall amortised O(1). No shrinking is
used.
The table itself is heap allocated, and points to other heap objects.
As such it's necessary to use markClosureTable to ensure the table is
used as a GC root to keep the table entries alive, and maintain proper
pointers to them as the GC moves heap objects about.
It is designed to be allocated and accesses exclusively from a single
capability, enabling it to work without any locking. It is thus similar
to the StablePtr table, but per-capability which removes the need for
locking. It _should_ also provide lower GC pause times with the
non-moving GC by spending only O(1) time in markClosureTable, vs O(n)
for markStablePtrTable.
The plan is to use it in some of the I/O managers to keep track of
in-flight I/O operations (but not timers). This allows the tracking
info to be kept on the (unpinned) GC heap, and shared with Haskell
code, and by putting a pointer to the tracking information in a table,
the index remains stable and can be passed via foreign code (like the
kernel).
-
78cb8dd5
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Add the StgAsyncIOOp closure type
This is intended to be used by multiple I/O managers to help with
tracking in-flight I/O operations.
It is called asynchronous because from the point of view of the RTS we
have many such operations in progress at once. From the point of view of
a Haskell thread of course it can look synchronous.
-
a2839896
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Add StgAsyncIOOp and StgTimeoutQueue to tso->block_info
These will be used by new I/O managers, for threads blocked on I/O or
timeouts.
-
fdc2451c
by Duncan Coutts at 2025-09-12T13:23:33-04:00
Add a new I/O manager based on poll()
This is a proof of concept I/O manager, to show how to add new ones
neatly, using the ClosureTable and TimeoutQueue infrastructure.
It uses the old unix poll() API, so it is of course limited in
performance by that, but it should have the benefit of wide
compatibility. Also we neatly avoid a name clash with the existing
select() I/O manager.
Compared to the select() I/O manager:
1. beause it uses poll() it is not limited to 1024 file descriptors
(but it's still O(n) so don't expect great performance);
2. it should have much faster threadDelay (when using it in lots of
threads at once) because it's based on the new TimeoutQueue which is
O(log n) rather than O(n).
Some of the code related to timers/timouts is put into a shared module
rts/posix/Timeout.{h,c} since it is intended to be shared with other
similar I/O managers.
-
6c273b76
by Duncan Coutts at 2025-09-12T13:23:34-04:00
Document the I/O managers in the user guide
and note the new poll I/O manager in the release notes.
-
824fab74
by Duncan Coutts at 2025-09-12T13:23:34-04:00
Use the poll() I/O manager by default
That is, for the non-threaded RTS, prefer the poll I/O manager over the
legacy select() one, if both can be enabled.
This patch is primarily for CI testing, so we should probably remove
this patch before merging. We can change defaults later after wider
testing and feedback.
-
39392532
by Luite Stegeman at 2025-09-12T13:24:16-04:00
Support larger unboxed sums
Change known constructor encoding for sums in interfaces to use
11 bits for both the arity and the alternative (up from 8 and 6,
respectively)
-
2af12e21
by Luite Stegeman at 2025-09-12T13:24:16-04:00
Decompose padding smallest-first in Cmm toplevel data constructors
This makes each individual padding value aligned
-
418fa78f
by Luite Stegeman at 2025-09-12T13:24:16-04:00
Use slots smaller than word as tag for smaller unboxed sums
This packs unboxed sums more efficiently by allowing
Word8, Word16 and Word32 for the tag field if the number of
constructors is small enough
-
8d7e912f
by Rodrigo Mesquita at 2025-09-12T17:57:24-04:00
ghc-toolchain: Use ByteOrder rather than new Endianness
Don't introduce a duplicate datatype when the previous one is equivalent
and already used elsewhere. This avoids unnecessary translation between
the two.
-
7d378476
by Rodrigo Mesquita at 2025-09-12T17:57:24-04:00
Read Toolchain.Target files rather than 'settings'
This commit makes GHC read `lib/targets/default.target`, a file with a
serialized value of `ghc-toolchain`'s `GHC.Toolchain.Target`.
Moreover, it removes all the now-redundant entries from `lib/settings`
that are configured as part of a `Target` but were being written into
`settings`.
This makes it easier to support multiple targets from the same compiler
(aka runtime retargetability). `ghc-toolchain` can be re-run many times
standalone to produce a `Target` description for different targets, and,
in the future, GHC will be able to pick at runtime amongst different
`Target` files.
This commit only makes it read the default `Target` configured in-tree
or configured when installing the bindist.
The remaining bits of `settings` need to be moved to `Target` in follow
up commits, but ultimately they all should be moved since they are
per-target relevant.
Fixes #24212
On Windows, the constant overhead of parsing a slightly more complex
data structure causes some small-allocation tests to wiggle around 1 to
2 extra MB (1-2% in these cases).
-------------------------
Metric Increase:
MultiLayerModulesTH_OneShot
T10421
T10547
T12234
T12425
T13035
T18140
T18923
T9198
TcPlugin_RewritePerf
-------------------------
-
e0780a16
by Rodrigo Mesquita at 2025-09-12T17:57:24-04:00
ghc-toolchain: Move TgtHasLibm to per-Target file
TargetHasLibm is now part of the per-target configuration
Towards #26227
-
8235dd8c
by Rodrigo Mesquita at 2025-09-12T17:57:24-04:00
ghc-toolchain: Move UseLibdw to per-Target file
To support DWARF unwinding, the RTS must be built with the -f+libdw flag
and with the -DUSE_LIBDW macro definition. These flags are passed on
build by Hadrian when --enable-dwarf-unwinding is specified at configure
time.
Whether the RTS was built with support for DWARF is a per-target
property, and as such, it was moved to the per-target
GHC.Toolchain.Target.Target file.
Additionally, we keep in the target file the include and library paths
for finding libdw, since libdw should be checked at configure time (be
it by configure, or ghc-toolchain, that libdw is properly available).
Preserving the user-given include paths for libdw facilitates in the
future building the RTS on demand for a given target (if we didn't keep
that user input, we couldn't)
Towards #26227
-
d5ecf2e8
by Rodrigo Mesquita at 2025-09-12T17:57:25-04:00
ghc-toolchain: Make "Support SMP" a query on a Toolchain.Target
"Support SMP" is merely a function of target, so we can represent it as
such in `ghc-toolchain`.
Hadrian queries the Target using this predicate to determine how to
build GHC, and GHC queries the Target similarly to report under --info
whether it "Support SMP"
Towards #26227
-
e07b031a
by Rodrigo Mesquita at 2025-09-12T17:57:25-04:00
ghc-toolchain: Make "tgt rts linker only supports shared libs" function on Target
Just like with "Support SMP", "target RTS linker only supports shared
libraries" is a predicate on a `Target` so we can just compute it when
necessary from the given `Target`.
Towards #26227
-
14123ee6
by Simon Peyton Jones at 2025-09-12T17:58:07-04:00
Solve forall-constraints via an implication, again
In this earlier commit:
commit 953fd8f1dc080f1c56e3a60b4b7157456949be29
Author: Simon Peyton Jones <simon.peytonjones@gmail.com>
Date: Mon Jul 21 10:06:43 2025 +0100
Solve forall-constraints immediately, or not at all
I used a all-or-nothing strategy for quantified constraints
(aka forall-constraints). But alas that fell foul of #26315,
and #26376.
So this MR goes back to solving a quantified constraint by
turning it into an implication; UNLESS we are simplifying
constraints from a SPECIALISE pragma, in which case the
all-or-nothing strategy is great. See:
Note [Solving a Wanted forall-constraint]
Other stuff in this MR:
* TcSMode becomes a record of flags, rather than an enumeration
type; much nicer.
* Some fancy footwork to avoid error messages worsening again
(The above MR made them better; we want to retain that.)
See `GHC.Tc.Errors.Ppr.pprQCOriginExtra`.
-------------------------
Metric Decrease:
T24471
-------------------------
-
e6c192e2
by Simon Peyton Jones at 2025-09-12T17:58:07-04:00
Add a test case for #26396
...same bug ast #26315
-
8f3d80ff
by Luite Stegeman at 2025-09-13T08:43:09+02:00
Use mkVirtHeapOffsets for reconstructing terms in RTTI
This makes mkVirtHeapOffsets the single source of truth for
finding field offsets in closures.
-
eb389338
by Luite Stegeman at 2025-09-13T08:43:09+02:00
Sort non-pointer fields by size for more efficient packing
This sorts non-pointer fields in mkVirtHeapOffsets, always
storing the largest field first. The relative order of
equally sized fields remains unchanged.
This reduces wasted padding/alignment space in closures with
differently sized fields.
-
99b233f4
by Alison at 2025-09-13T16:51:04-04:00
ghc-heap: Fix race condition with profiling builds
Apply the same fix from Closures.hs (64fd0fac83) to Heap.hs by adding
empty imports to make way-dependent dependencies visible to `ghc -M`.
Fixes #15197, #26407
-
77deaa7a
by Cheng Shao at 2025-09-14T21:29:45-04:00
hadrian: build in-tree gmp with -fvisibility=hidden
When hadrian builds in-tree gmp, it should build the shared objects
with -fvisibility=hidden. The gmp symbols are only used by bignum
logic in ghc-internal and shouldn't be exported by the ghc-internal
shared library. We should always strive to keep shared library symbol
table lean, which benefits platforms with slow dynamic linker or even
hard limits about how many symbols can be exported (e.g. macos dyld,
win32 dll and wasm dyld).
-
42a18960
by Cheng Shao at 2025-09-14T21:30:26-04:00
Revert "wasm: add brotli compression for ghci browser mode"
This reverts commit 731217ce68a1093b5f9e26a07d5bd2cdade2b352.
Benchmarks show non-negligible overhead when browser runs on the same
host, which is the majority of actual use cases.
-
e6755b9f
by Cheng Shao at 2025-09-14T21:30:26-04:00
wasm: remove etag logic in ghci browser mode web server
This commit removes the etag logic in dyld script's ghci browser mode
web server. It was meant to support caching logic of wasm shared
libraries, but even if the port is manually specified to make caching
even relevant, for localhost the extra overhead around etag logic is
simply not worth it according to benchmarks.
-
7c1c2ce3
by Ben Gamari at 2025-09-16T12:55:02+02:00
StgToByteCode: Don't assume that data con workers are nullary
Previously StgToByteCode assumed that all data-con workers were of a
nullary representation. This is not a valid assumption, as seen
in #23210, where an unsaturated application of a unary data
constructor's worker resulted in invalid bytecode. Sadly, I have not yet
been able to reduce a minimal testcase for this.
Fixes #23210.
-
85c98706
by Ben Gamari at 2025-09-16T12:55:02+02:00
testsuite: Mark T23146* as unbroken