-
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.
-
ac5859b9
by sheaf at 2025-09-16T14:58:38-04:00
Add 'Outputable Natural' instance
This commit adds an Outputable instance for the Natural natural-number type,
as well as a "natural :: Natural -> SDoc" function that mirrors the existing
"integer" function.
-
d48ebc23
by Cheng Shao at 2025-09-16T14:59:18-04:00
autoconf: emit warning instead of error for FIND_PYTHON logic
This patch makes FIND_PYTHON logic emit warning instead of error, so
when the user doesn't expect to run the testsuite driver (especially
when installing a bindist), python would not be mandatory. Fixes #26347.
-
54b5950e
by Sylvain Henry at 2025-09-17T04:45:18-04:00
Print fully qualified unit names in name mismatch
It's more user-friendly to directly print the right thing instead of
requiring the user to retry with the additional `-dppr-debug` flag.
-
403cb665
by Ben Gamari at 2025-09-17T04:46:00-04:00
configure: Fix consistency between distrib and source CC check
Previously distrib/configure.ac did not
include `cc`.
Closes #26394.
-
2dcd4cb9
by Oleg Grenrus at 2025-09-17T04:46:41-04:00
Use isPrint in showUnique
The comment say
```
-- Avoid emitting non-printable characters in pretty uniques. See #25989.
```
so let the code do exactly that.
There are tags (at least : and 0 .. 9) which weren't in A .. z range.
-
e5dd754b
by Oleg Grenrus at 2025-09-17T04:46:42-04:00
Shorten in-module links in hyperlinked source
Instead of href="This.Module#ident" to just "#ident"
-
63189b2c
by Oleg Grenrus at 2025-09-17T04:46:42-04:00
Use showUnique in internalAnchorIdent
Showing the key of Unique as a number is generally not a great idea.
GHC Unique has a tag in high bits, so the raw number is unnecessarily
big.
So now we have
```html
<a href="#l-rvgK"><span class="hs-identifier hs-var hs-var">bar</span></a>
```
instead of
```html
<a href="#local-6989586621679015689"><span class="hs-identifier hs-var hs-var">bar</span></a>
```
Together with previous changes of shorter intra-module links the effect
on compressed files is not huge, that is expected as we simply remove
repetitive contents which pack well.
```
12_694_206 Agda-2.9.0-docs-orig.tar.gz
12_566_065 Agda-2.9.0-docs.tar.gz
```
However when unpacked, the difference can be significant,
e.g. Agda's largest module source got 5% reduction:
```
14_230_117 Agda.Syntax.Parser.Parser.html
13_422_109 Agda.Syntax.Parser.Parser.html
```
The whole hyperlinked source code directory got similar reduction
```
121M Agda-2.9.0-docs-orig/src
114M Agda-2.9.0-docs/src
```
For the reference, sources are about 2/3 of the generated haddocks
```
178M Agda-2.9.0-docs-old
172M Agda-2.9.0-docs
```
so we get around 3.5% size reduction overall. Not bad for a small local
changes.
-
6f63f57b
by Stefan Schulze Frielinghaus at 2025-09-17T04:47:22-04:00
rts: Fix alignment for gen_workspace #26334
After a0fa4941903272c48b050d24e93eec819eff51bd bootstrap is broken on
s390x and errors out with
rts/sm/GCThread.h:207:5: error:
error: alignment of array elements is greater than element size
207 | gen_workspace gens[];
| ^~~~~~~~~~~~~
The alignment constraint is applied via the attribute to the type
gen_workspace and leaves the underlying type struct gen_workspace_
untouched. On Aarch64, x86, and s390x the struct has a size of 128
bytes. On Aarch64 and x86 the alignments of 128 and 64 are divisors of
the size, respectively, which is why the type is a viable member type
for an array. However, on s390x, the alignment is 256 and therefore is
not a divisor of the size and hence cannot be used for arrays.
Basically I see two fixes here. Either decrease the alignment
requirement on s390x, or by applying the alignment constraint on the
struct itself. The former might affect performance as noted in
a0fa4941903272c48b050d24e93eec819eff51bd. The latter introduces padding
bits whenever necessary in order to ensure that
sizeof(gen_workspace[N])==N*sizeof(gen_workspace) holds which is done by
this patch.
-
06d25623
by Cheng Shao at 2025-09-17T19:32:27-04:00
ghci: add :shell command
This patch adds a new :shell command to ghci which works similarly to
:!, except it guarantees to run the command via sh -c. On POSIX hosts
the behavior is identical to :!, but on Windows it uses the msys2
shell instead of system cmd.exe shell. This is convenient when writing
simple ghci scripts that run simple POSIX commands, and the behavior
can be expected to be coherent on both Windows and POSIX.
Co-authored-by: Codex <codex@openai.com>
-
186054f7
by Cheng Shao at 2025-09-17T19:32:27-04:00
testsuite: remove legacy :shell trick
This commit makes use of the built-in :shell functionality in ghci in
the test cases, and remove the legacy :shell trick.
-
0a3a4aa3
by Cheng Shao at 2025-09-17T19:32:27-04:00
docs: document :shell in ghci
This commit documents the :shell command in ghci.
Co-authored-by: Codex <codex@openai.com>
-
a4ff12bb
by Cheng Shao at 2025-09-17T19:33:09-04:00
ghc-internal: fix codepages program
codepages was not properly updated during the base -> ghc-internal
migration, this commit fixes it.
-
7e094def
by Cheng Shao at 2025-09-17T19:33:09-04:00
ghc-internal: relax ucd2haskell cabal upper bounds
This commit relaxes ucd2haskell cabal upper bounds to make it runnable
via ghc 9.12/9.14.
-
7077c9f7
by Cheng Shao at 2025-09-17T19:33:09-04:00
ghc-internal: update to unicode 17.0.0
This commit updates the generated code in ghc-internal to match
unicode 17.0.0.
-
cef8938f
by sheaf at 2025-09-17T19:34:09-04:00
Bad record update msg: allow out-of-scope datacons
This commit ensures that, when we encounter an invalid record update
(because no constructor exists which contains all of the record fields
mentioned in the record update), we graciously handle the situation in
which the constructors themselves are not in scope. In that case,
instead of looking up the constructors in the GlobalRdrEnv, directly
look up their GREInfo using the lookupGREInfo function.
Fixes #26391
-
a2d9d7c2
by sheaf at 2025-09-17T19:34:09-04:00
Improve Notes about disambiguating record updates
This commit updates the notes [Disambiguating record updates] and
[Type-directed record disambiguation], in particular adding more
information about the deprecation status of type-directed disambiguation
of record updates.
-
de44e69e
by sheaf at 2025-09-19T05:16:51-04:00
Enable TcM plugins in initTc
This commit ensures that we run typechecker plugins and defaulting
plugins whenever we call initTc.
In particular, this ensures that the pattern-match checker, which calls
'initTcDsForSolver' which calls 'initTc', runs with typechecker plugins
enabled. This matters for situations like:
merge :: Vec n a -> Vec n a -> Vec (2 * n) a
merge Nil Nil = Nil
merge (a <: as) (b <: bs) = a :< (b <: merge as bs)
in which we need the typechecker plugin to run in order to tell us that
the Givens would be inconsistent in the additional equation
merge (_ <: _) Nil
and thus that the equation is not needed.
Fixes #26395
-
2c378ad2
by Cheng Shao at 2025-09-19T05:17:33-04:00
rel-eng: update fedora image to 42
This patch is a part of #25876 and updates fedora image to 42.
-
0a9d9ffc
by Sylvain Henry at 2025-09-19T13:12:14-04:00
Fix output of T14999 (#23685)
Fix output of T14999 to:
- take into account the +1 offset to DW_AT_low_pc (see Note [Info Offset])
- always use Intel's syntax to force consistency: it was reported that
sometimes GDB prints `jmpq` instead of `jmp` with the AT&T syntax
-
1480872a
by Vladislav Zavialov at 2025-09-19T13:12:54-04:00
Fix PREP_MAYBE_LIBRARY in prep_target_file.m4
This change fixes a configure error introduced in:
commit 8235dd8c4945db9cb03e3be3c388d729d576ed1e
ghc-toolchain: Move UseLibdw to per-Target file
Now the build no longer fails with:
acghc-toolchain: Failed to read a valid Target value from hadrian/cfg/default.target
-
d1d9e39e
by Ben Gamari at 2025-09-19T18:24:52-04:00
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.
-
3eeecd50
by Ben Gamari at 2025-09-19T18:24:53-04:00
testsuite: Mark T23146* as unbroken
-
2e73f342
by sheaf at 2025-09-19T18:24:53-04:00
Add test for #26216
-
c2efb912
by Sven Tennie at 2025-09-19T18:25:36-04:00
Generate correct test header
This increases convenience when copying & pasting...
-
d2fb811e
by Sven Tennie at 2025-09-19T18:25:36-04:00
foundation test: Fix shift amount (#26248)
Shift primops' results are only defined for shift amounts of 0 to word
size - 1. The approach is similar to testing div-like operations (which
have a constraint regarding zero operands.)
This was partly vibe coded (https://github.com/supersven/ghc/pull/1) but
then heavily refactored.
-
a62ce115
by Andreas Klebinger at 2025-09-19T18:26:18-04:00
Tweak jspace test
I've given it a longer timeout, and tweaked the test file generation
to speed it up a bit. Hopefully that is enough to make it constentily pass.
Last but not least it now also always uses three threads.
-
0f034942
by Cheng Shao at 2025-09-19T18:26:59-04:00
rts: remove obsolete CC_SUPPORTS_TLS logic
This patch removes obsolete CC_SUPPORTS_TLS logic throughout the rts,
given __thread is now uniformly supported by C toolchains of all
platforms we currently support.
-
ef705655
by Cheng Shao at 2025-09-19T18:27:41-04:00
rts: remove obsolete HAS_VISIBILITY_HIDDEN logic
This patch removes obsolete HAS_VISIBILITY_HIDDEN logic throughout the
rts, given __attribute__((visibility("hidden"))) is uniformly
supported by C toolchains of all platforms we currently support.
-
9fdc1f7d
by Cheng Shao at 2025-09-19T18:28:21-04:00
rts: remove -O3 pragma hack in Hash.c
This patch removes an obsolete gcc pragma to specify -O3 in Hash.c.
Hadrian already passes the right flag.
-
b8cfa8f7
by Cheng Shao at 2025-09-19T18:29:01-04:00
rts: remove obsolete COMPILING_WINDOWS_DLL logic
This patch removes obsolete COMPILING_WINDOWS_DLL logic throughout the
rts. They were once used for compiling to win32 DLLs, but we haven't
been able to compile Haskell units to win32 DLLs for many years now,
due to PE format's restriction of no more than 65536 exported symbols
in a single DLL.
-
bb760611
by Cheng Shao at 2025-09-19T18:29:42-04:00
wasm: bump browser_wasi_shim to 0.4.2
This patch bumps the browser_wasi_shim dependency of wasm dyld script
to 0.4.2.
-
8b0940db
by Cheng Shao at 2025-09-20T06:48:05-04:00
compiler: move Binary instance of Map to GHC.Utils.Binary
This patch moves `Binary` instance of `Map` from `haddock-api` to
`GHC.Utils.Binary`. This also allows us to remove a redundant instance
defined for `NameEntityInfo`, which is a type synonym for `Map`.
-
4a8fed75
by Vladislav Zavialov at 2025-09-20T06:48:47-04:00
Fix keyword in ExplicitNamespaces error message (#26418)
Consider this module header and the resulting error:
{-# LANGUAGE NoExplicitNamespaces #-}
module T26418 (data HeadC) where
-- error: [GHC-47007]
-- Illegal keyword 'type'
Previously, the error message would mention 'type' (as shown above),
even though the user wrote 'data'. This has now been fixed.
The error location has also been corrected: it is now reported at the
keyword position rather than at the position of the associated
import/export item.
-
867c2675
by Cheng Shao at 2025-09-20T06:49:28-04:00
wasm: fix dyld handling for forward declared GOT.func items
This patch fixes wasm shared linker's handling of forward declared
GOT.func items, see linked issue for details. Also adds T26430 test to
witness the fix. Fixes #26430.
Co-authored-by: Codex <codex@openai.com>
-
e7df6cc0
by Simon Peyton Jones at 2025-09-23T14:34:39-04:00
Improve pretty printer for HsExpr
Given a very deeply-nested application, it just kept printing
deeper and deeper. This small change makes it cut off.
Test is in #26330, but we also get a dramatic decrease in compile
time for perf/compiler/InstanceMatching:
InstanceMatching 4,086,884,584 1,181,767,232 -71.1% GOOD
Why? Because before we got a GIGANTIC error message that took
ages to pretty-print; now we get this much more civilised message
(I have removed some whitespace.)
Match.hs:1007:1: error:
• No instance for ‘Show (F001 a)’ arising from a use of ‘showsPrec’
• In the second argument of ‘showString’, namely
‘(showsPrec
11 b1
(GHC.Internal.Show.showSpace
(showsPrec
11 b2
(GHC.Internal.Show.showSpace
(showsPrec
11 b3
(GHC.Internal.Show.showSpace
(showsPrec
11 b4
(GHC.Internal.Show.showSpace
(showsPrec
11 b5
(GHC.Internal.Show.showSpace
(showsPrec
11 b6
(GHC.Internal.Show.showSpace (showsPrec ...)))))))))))))’
-----------------------
The main payload is
* At the start of `pprExpr`
* In the defn of `pprApp`
A little bit of refactoring:
* It turned out that we were setting the default cut-off depth to a
fixed value in two places, so changing one didn't change the other.
See defaultSDocDepth and defaultSDocCols
* I refactored `pprDeeperList` a bit so I could understand it better.
Because the depth calculation has changed, there are lots of small
error message wibbles.
Metric Decrease:
InstanceMatching
-
209f0158
by Simon Peyton Jones at 2025-09-23T14:34:39-04:00
Use Outputable.ellipsis rather than text "..."
-
64bb0e37
by Sylvain Henry at 2025-09-23T14:35:56-04:00
deriveConstants: automatically pass -fcommon CC flag (#26393)
By mistake we tried to use deriveConstants without passing
`--gcc-flag -fcommon` (which Hadrian does) and it failed.
This patch:
1. adds parsing support for constants stored in the .bss section (i.e.
when -fcommon isn't passed)
2. enables passing `-fcommon` automatically to the C compiler because
Windows requires this for subtle reasons
3. Documents the subtle reasons
(1) isn't strictly necessary because we always do (2) but it does no
harm and it is still useful if the CC flags ever contain -fno-common
-
afcdf92f
by Oleg Grenrus at 2025-09-23T14:36:41-04:00
Don't wrap spaces in <span>s
Doing similar comparison as in 63189b2ceca07edf4e179f4180ca60d470c62cb3
With this change the gzipped documentation is now 2% smaller (previously 1%)
12_694_206 Agda-2.9.0-docs-orig.tar.gz
12_436_829 Agda-2.9.0-docs.tar.gz
Unzipped docs are 5% smaller (previously 3%)
178M Agda-2.9.0-docs-orig
169M Agda-2.9.0-docs
Individual hyperlinked sources are around 7-10% smaller (previously 5%)
(`Parser` module is generated by happy and has relatively little whitespace)
14_230_117 Agda.Syntax.Parser.Parser.html
13_220_758 Agda.Syntax.Parser.Parser.html
Agda's hyperlinked sources are 9% smaller now:
121M Agda-2.9.0-docs-orig/src
110M Agda-2.9.0-docs/src
-
67de53a6
by Cheng Shao at 2025-09-23T14:37:31-04:00
rts: remove obsolete __GNUC__ related logic
This patch removes obsolete `__GNUC__` related logic, given on any
currently supported platform and toolchain, `__GNUC__ >= 4` is
universally true. Also pulls some other weeds and most notably, use
`__builtin___clear_cache` for clang as well, since clang has supported
this gcc intrinsic since 2014, see
https://github.com/llvm/llvm-project/commit/c491a8d4577052bc6b3b4c72a7db6a7cfcbc2ed0.
-
c4d32493
by Sven Tennie at 2025-09-23T20:40:57-04:00
RV64: Fix: Add missing truncation to MO_S_Shr (#26248)
Sub-double word (<W64) registers need to be truncated after the
operation.
-
41dce477
by Sven Tennie at 2025-09-23T20:40:57-04:00
RV64: Cleanup shift emitting cases/code
Remove overlapping cases to make the shift logic easier to understand.
-
0a601c30
by Alex Washburn at 2025-09-23T20:41:41-04:00
Correcting LLVM linking of Intel BMI intrinsics pdep{8,16} and pext{8,16}.
This patch fixes #26065.
The LLVM interface does not expose bindings to:
- llvm.x86.bmi.pdep.8
- llvm.x86.bmi.pdep.16
- llvm.x86.bmi.pext.8
- llvm.x86.bmi.pext.16
So calls are instead made to llvm.x86.bmi.{pdep,pext}.32 in these cases,
with pre/post-operation truncation to constrain the logical value range.
-
89e8ff3d
by Peng Fan at 2025-09-23T20:42:37-04:00
NCG/LA64: Implement MO_BSwap and MO_BRev with bit-manipulation Instructions
-
50f6be09
by Sylvain Henry at 2025-09-23T20:43:29-04:00
Allow Core plugins to access unoptimized Core (#23337)
Make the first simple optimization pass after desugaring a real CoreToDo
pass. This allows CorePlugins to decide whether they want to be executed
before or after this pass.
-
30ef0aac
by Simon Hengel at 2025-09-23T20:44:12-04:00
docs: Fix typo in scoped_type_variables.rst
-
f8919262
by Cheng Shao at 2025-09-23T20:44:54-04:00
ghci: fix bootstrapping with 9.12.3-rc1 and above
This patch fixes bootstrapping GHC with 9.12.3-rc1 and above. ghci
defines `Binary` instance for `HalfWord` in `ghc-heap`, which is a
proper `newtype` in 9.14 and starting from 9.12.3. Given we don't
build `ghc-heap` in stage0, we need to fix this predicate so that it
corresponds to the boot ghc versions that contain the right version of
`ghc-heap`.
-
a7f15858
by sheaf at 2025-09-24T09:49:53-04:00
User's guide: clarify optimisation of INLINABLE unfoldings
This updates the user's guide section on INLINABLE pragmas to explain how
the unfoldings of inlineable functions are optimised. The user's guide incorrectly
stated that the RHS was not optimised at all, but this is not true. Instead, GHC
is careful about phase control to optmise the RHS while retaining the guarantee
that GHC behaves as if the original RHS had been written.
-
495886d9
by Rodrigo Mesquita at 2025-09-24T09:50:35-04:00
cleanup: Delete historical artifact of COMPILING_WINDOWS_DLL
Namely, drop the obsolete
- DLL_IMPORT_RTS
- DLL_IMPORT_DATA_VAR
- DLL_IMPORT_DATA_VARNAME
- DLL_IMPORT_DATA_REF
These macros were not doing anything and placed inconsistently
Looking at the git logs reveal these macros were used to support
dynamic libraries on Win32, a feature that was dropped
in b8cfa8f741729ef123569fb321c4b2ab4a1a941c
This allows us to get rid of the rts/DLL.h file too.
-
5ae89054
by Sylvain Henry at 2025-09-24T17:07:00-04:00
Allow disabling builtin rules (#20298)
Add a way to disable built-in rules programmatically and with a debug flag.
I also took the opportunity to add a debug flag to disable bignum rules,
which was only possible programmatically (e.g. in a plugin).
-
135242ca
by Rodrigo Mesquita at 2025-09-24T17:07:44-04:00
Don't use build CFLAGS and friends as target settings
In the GHC in tree configure, `CFLAGS`, `CXXFLAGS`, and similar tool
configuration flags apply to the BUILD phase of the compiler, i.e. to
the tools run to compile GHC itself.
Notably, they should /not/ be carried over to the Target settings, i.e.
these flags should /not/ apply to the tool which GHC invokes at runtime.
Fixes #25637
-
b418408b
by Irene Knapp at 2025-09-25T09:47:54-04:00
Document etymology of "bind" as the name for `>>=`
It took me twenty years of contemplation to realize why it's called that.
I therefore feel that it may not be obvious to beginners.
-
e9c5e46f
by Brandon Chinn at 2025-09-25T09:48:36-04:00
Fix tabs in string gaps (#26415)
Tabs in string gaps were broken in bb030d0d because previously, string gaps were manually parsed, but now it's lexed by the usual Alex grammar and post-processed after successful lexing.
It broke because of a discrepancy between GHC's lexer grammar and the Haskell Report. The Haskell Report includes tabs in whitechar:
whitechar → newline | vertab | space | tab | uniWhite
$whitechar used to include tabs until 18 years ago, when it was removed in order to exclude tabs from $white_no_nl in order to warn on tabs: 6e202120. In this MR, I'm adding \t back into $whitechar, and explicitly excluding \t from the $white_no_nl+ rule ignoring all whitespace in source code, which more accurately colocates the "ignore all whitespace except tabs, which is handled in the next line" logic.
As a side effect of this MR, tabs are now allowed in pragmas; currently, a pragma written as {-# \t LANGUAGE ... #-} is interpreted as the tab character being the pragma name, and GHC warns "Unrecognized pragma". With this change, tabs are ignored as whitespace, which more closely matches the Report anyway.
-
8bf5b309
by Cheng Shao at 2025-09-25T09:49:18-04:00
wasm: remove the --no-turbo-fast-api-calls hack from dynamic linker shebang
This patch removes the `--no-turbo-fast-api-calls` hack from the dyld
script shebang; it was used to workaround v8 fast call coredumps in
nodejs and no longer needed, and comes with a performance penalty,
hence the removal.
-
c1cab0c3
by Sylvain Henry at 2025-09-26T10:36:30-04:00
Revert "Add necessary flag for js linking"
This reverts commit 84f68e2231b2eddb2e1dc4e90af394ef0f2e803f.
This commit didn't have the expected effect. See discussion in #26290.
Instead we export HEAP8 and HEAPU8 from rts/js/mem.js
-
0a434a80
by Sylvain Henry at 2025-09-26T10:36:30-04:00
JS: export HEAPU8 (#26290)
This is now required by newer Emscripten versions.
-
b10296a9
by Andreas Klebinger at 2025-09-26T10:37:11-04:00
sizeExpr: Improve Tick handling.
When determining if we scrutinize a function argument we
now properly look through ticks. Fixes #26444.
-
d9e2a9a7
by mniip at 2025-09-26T16:00:50-04:00
rts: Refactor parsing of -h flags
We have a nontrivial amount of heap profiling flags available in the
non-profiled runtime, so it makes sense to reuse the parsing code
between the profiled and the non-profiled runtime, only restricting
which flags are allowed.
-
089e45aa
by mniip at 2025-09-26T16:00:50-04:00
rts: Fix parsing of -h options with braces
When the "filter by" -h options were introduced in
bc210f7d267e8351ccb66972f4b3a650eb9338bb, the braces were mandatory.
Then in 3c22fb21fb18e27ce8d941069a6915fce584a526, the braces were made
optional. Then in d1ce35d2271ac8b79cb5e37677b1a989749e611c the brace
syntax stopped working, and no one seems to have noticed.
-
423f1472
by mniip at 2025-09-26T16:00:50-04:00
rts: add -hT<type> and -hi<table id> heap filtering options (#26361)
They are available in non-profiled builds.
Along the way fixed a bug where combining -he<era> and -hr<retainer>
would ignore whether the retainer matches or not.
-
4cda4785
by mniip at 2025-09-26T16:00:50-04:00
docs: Document -hT<type> and -hi<addr>
-
982ad30f
by mniip at 2025-09-26T16:00:50-04:00
rts: Refactor dumping the heap census
Always do the printing of the total size right next to where the bucket
label is printed. This prevents accidentally printing a label without
the corresponding amount.
Fixed a bug where exactly this happened for -hi profile and the 0x0
(uncategorized) info table.
There is now also much more symmetry between fprintf(hp_file,...) and
the corresponding traceHeapProfSampleString.
-
8cbe006a
by Cheng Shao at 2025-09-26T16:01:34-04:00
hadrian: fix GHC.Platform.Host generation for cross stage1
This patch fixes incorrectly GHC.Platform.Host generation logic for
cross stage1 in hadrian (#26449). Also adds T26449 test case to
witness the fix.
Co-authored-by: Codex <codex@openai.com>
-
0ddd0fdc
by soulomoon at 2025-09-28T19:24:10-04:00
Remove hptAllInstances usage during upsweep
Previously, during the upsweep phase when
checking safe imports, we were loading the module
interface with runTcInteractive, which in turn calls
hptAllInstances. This accesses non-below modules
from the home package table.
Change the implementation of checkSafeImports
to use initTcWithGbl and loadSysInterface to load the
module interface, since we already have TcGblEnv at hand.
This eliminates the unnecessary use of runTcInteractive
and hptAllInstances during the upsweep phase.
-
e05c496c
by Ben Gamari at 2025-09-28T19:24:59-04:00
base: Update changelog to reflect timing of IOPort# removal
This change will make 9.14 afterall.
-
bdc9d130
by Cheng Shao at 2025-09-28T19:25:45-04:00
rts: fix wasm JSFFI initialization constructor code
This commit fixes wasm JSFFI initialization constructor code so that
the constructor is self-contained and avoids invoking a fake
__main_argc_argv function. The previous approach of reusing
__main_void logic in wasi-libc saves a tiny bit of code, at the
expense of link-time trouble whenever GHC links a wasm module without
-no-hs-main, in which case the driver-generated main function would
clash with the definition here, resulting in a linker error. It's
simply better to avoid messing with the main function, and it would
additionally allow linking wasm32-wasi command modules that does make
use of synchronous JSFFI.
-
5d59fc8f
by Cheng Shao at 2025-09-28T19:26:27-04:00
rts: provide stub implementations of ExecPage functions for wasm
This patch provides stub implementations of ExecPage functions for
wasm. They are never actually invoked at runtime for any non-TNTC
platform, yet they can cause link-time errors of missing symbols when
the GHCi.InfoTable module gets linked into the final wasm module (e.g.
a GHC API program).
-
a4d664c7
by Cheng Shao at 2025-09-29T17:29:22+02:00
compiler/ghci: replace the LoadDLL message with LoadDLLs
As a part of #25407, this commit changes the LoadDLL message to
LoadDLLs, which takes a list of DLL paths to load and returns the list
of remote pointer handles. The wasm dyld is refactored to take
advantage of LoadDLLs and harvest background parallelism. On other
platforms, LoadDLLs is based on a fallback codepath that does
sequential loading.
The driver is not actually emitting singular LoadDLLs message with
multiple DLLs yet, this is left in subsequent commits.
Co-authored-by: Codex <codex@openai.com>
-
c7fc4bae
by Cheng Shao at 2025-09-29T17:29:22+02:00
driver: separate downsweep/upsweep phase in loadPackages'
This commit refactors GHC.Linker.Loader.loadPackages' to be separated
into downsweep/upsweep phases:
- The downsweep phase performs dependency analysis and generates a
list of topologically sorted packages to load
- The upsweep phase sequentially loads these packages by calling
loadPackage
This is a necessary refactoring to make it possible to make loading of
DLLs concurrent.
-
ab180104
by Cheng Shao at 2025-09-29T17:57:19+02:00
driver: emit single LoadDLLs message to load multiple DLLs
This commit refactors the driver so that it emits a single LoadDLLs
message to load multiple DLLs in GHC.Linker.Loader.loadPackages'.
Closes #25407.
-------------------------
Metric Increase:
MultiLayerModulesTH_OneShot
TcPlugin_RewritePerf
-------------------------
Co-authored-by: Codex <codex@openai.com>
-
9c304ec0
by Sean D. Gillespie at 2025-09-29T19:57:07-04:00
Fix SIZED_BIN_OP_TY_INT casts in RTS interpreter
Correct `SIZED_BIN_OP_TY_INT` cast to integer. Previously, it cast
its second operand as its parameter `ty`. This does not currently
cause any issues, since we are only using it for bit shifts.
Fixes #26287
-
a1de535f
by Luite Stegeman at 2025-09-30T18:40:28-04:00
rts: Fix lost wakeups in threadPaused for threads blocked on black holes
The lazy blackholing code in threadPaused could overwrite closures
that were already eagerly blackholed, and as such wouldn't have a
marked update frame. If the black hole was overwritten by its
original owner, this would lead to an undetected collision, and
the contents of any existing blocking queue being lost.
This adds a check for eagerly blackholed closures and avoids
overwriting their contents.
Fixes #26324
-
b7e21e49
by Luite Stegeman at 2025-09-30T18:40:28-04:00
rts: push the correct update frame in stg_AP_STACK
The frame contains an eager black hole (__stg_EAGER_BLACKHOLE_info) so
we should push an stg_bh_upd_frame_info instead of an stg_upd_frame_info.
-
02a7c18a
by Cheng Shao at 2025-09-30T18:41:27-04:00
ghci: fix lookupSymbolInDLL behavior on wasm
This patch fixes lookupSymbolInDLL behavior on wasm to return Nothing
instead of throwing. On wasm, we only have lookupSymbol, and the
driver would attempt to call lookupSymbolInDLL first before falling
back to lookupSymbol, so lookupSymbolInDLL needs to return Nothing
gracefully for the fallback behavior to work.
-
aa0ca5e3
by Cheng Shao at 2025-09-30T18:41:27-04:00
hadrian/compiler: enable internal-interpreter for ghc library in wasm stage1
This commit enables the internal-interpreter flag for ghc library in
wasm stage1, as well as other minor adjustments to make it actually
possible to launch a ghc api session that makes use of the internal
interpreter. Closes #26431 #25400.
-
69503668
by Cheng Shao at 2025-09-30T18:41:27-04:00
testsuite: add T26431 test case
This commit adds T26431 to testsuite/tests/ghci-wasm which goes
through the complete bytecode compilation/linking/running pipeline in
wasm, so to witness that the ghc shared library in wasm have full
support for internal-interpreter.
-
e9445c01
by Matthew Pickering at 2025-09-30T18:42:23-04:00
driver: Load bytecode static pointer entries during linking
Previously the entries were loaded too eagerly, during upsweep, but we
should delay loading them until we know that the relevant bytecode
object is demanded.
Towards #25230
-
b8307eab
by Cheng Shao at 2025-09-30T18:43:14-04:00
autoconf/ghc-toolchain: remove obsolete C99 check
This patch removes obsolete c99 check from autoconf/ghc-toolchain. For
all toolchain & platform combination we support, gnu11 or above is
already supported without any -std flag required, and our RTS already
required C11 quite a few years ago, so the C99 check is completely
pointless.
-
9c293544
by Simon Peyton Jones at 2025-10-01T09:36:10+01:00
Fix buglet in GHC.Core.Unify.uVarOrFam
We were failing to match two totally-equal types!
This led to #26457.
-
554487a7
by Rodrigo Mesquita at 2025-10-01T23:04:43-04:00
cleanup: Drop obsolete comment about HsConDetails
HsConDetails used to have an argument representing the type of the
tyargs in a list:
data HsConDetails tyarg arg rec
= PrefixCon [tyarg] [arg]
This datatype was shared across 3 synonyms: HsConPatDetails,
HsConDeclH98Details, HsPatSynDetails. In the latter two cases, `tyarg`
was instanced to `Void` meaning the list was always empty for these
cases.
In 7b84c58867edca57a45945a20a9391724db6d9e4, this was refactored such
that HsConDetails no longer needs a type of tyargs by construction. The
first case now represents the type arguments in the args type itself,
with something like:
ConPat "MkE" [InvisP tp1, InvisP tp2, p1, p2]
So the deleted comment really is just obsolete.
Fixes #26461
-
6992ac09
by Cheng Shao at 2025-10-02T07:27:55-04:00
testsuite: remove unused expected output files
This patch removes unused expected output files in the testsuites on
platforms that we no longer support.
-
39eaaaba
by Ben Gamari at 2025-10-02T07:28:45-04:00
rts: Dynamically initialize built-in closures
To resolve #26166 we need to eliminate references to undefined symbols
in the runtime system. One such source of these is the runtime's
static references to `I#` and `C#` due the `stg_INTLIKE` and
`stg_CHARLIKE` arrays.
To avoid this we make these dynamic, initializing them during RTS
start-up.
-
c254c54b
by Cheng Shao at 2025-10-02T07:29:33-04:00
compiler: only invoke keepCAFsForGHCi if internal-interpreter is enabled
This patch makes the ghc library only invoke keepCAFsForGHCi if
internal-interpreter is enabled. For cases when it's not (e.g. the
host build of a cross ghc), this avoids unnecessarily retaining all
CAFs in the heap. Also fixes the type signature of c_keepCAFsForGHCi
to match the C ABI.
-
c9ec4d43
by Simon Hengel at 2025-10-02T18:42:20-04:00
Update copyright in documentation
-
da9633a9
by Matthew Pickering at 2025-10-02T18:43:04-04:00
loader: Unify loadDecls and loadModuleLinkables functions
These two functions nearly did the same thing. I have refactored them so
that `loadDecls` now calls `loadModuleLinkables`.
Fixes #26459
-
5db98d80
by Simon Hengel at 2025-10-02T18:43:53-04:00
Fix typo
-
1275d360
by Matthew Pickering at 2025-10-03T06:05:56-04:00
testsuite: Use ghci_ways to set ways in PackedDataCon/UnboxedTuples/UnliftedDataTypeInterp tests
These tests reimplemented the logic from `valid_way` in order to
determine what ways to run. It's easier to use this combination of
`only_ways` and `extra_ways` to only run in GHCi ways and always run in
GHCi ways.
-
c06b534b
by Matthew Pickering at 2025-10-03T06:06:40-04:00
Rename interpreterBackend to bytecodeBackend
This is preparation for creating bytecode files.
The "interpreter" is one way in which we can run bytecode objects. It is
more accurate to describe that the backend produces bytecode, rather
than the means by which the code will eventually run.
The "interpreterBackend" binding is left as a deprecated alias.
-
41bdb16f
by Andreas Klebinger at 2025-10-06T18:04:34-04:00
Add a perf test for #26425
-
1da0c700
by Andreas Klebinger at 2025-10-06T18:05:14-04:00
Testsuite: Silence warnings about Wx-partial in concprog001
-
7471eb6a
by sheaf at 2025-10-07T21:39:43-04:00
Improve how we detect user type errors in types
This commit cleans up all the code responsible for detecting whether a
type contains "TypeError msg" applications nested inside it. All the
logic is now in 'userTypeError_maybe', which is always deep. Whether
it looks inside type family applications is determined by the passed-in
boolean flag:
- When deciding whether a constraint is definitely insoluble, don't
look inside type family applications, as they may still reduce -- in
which case the TypeError could disappear.
- When reporting unsolved constraints, look inside type family
applications: they had the chance to reduce but didn't, and the
custom type error might contain valuable information.
All the details are explained in Note [Custom type errors in constraints]
in GHC.Tc.Types.Constraint.
Another benefit of this change is that it allows us to get rid of the
deeply dodgy 'getUserTypeErrorMsg' function.
This commit also improves the detection of custom type errors, for
example in equality constraints:
TypeError blah ~# rhs
It used to be the case that we didn't detect the TypeError on the LHS,
because we never considered that equality constraints could be insoluble
due to the presence of custom type errors. Addressing this oversight
improves detection of redundant pattern match warnings, fixing #26400.
-
29955267
by Rodrigo Mesquita at 2025-10-07T21:40:25-04:00
cleanup: Drop obsolete settings from config.mk.in
These values used to be spliced into the bindist's `config.mk` s.t. when
`make` was run, the values were read and written into the bindist installation `settings` file.
However, we now carry these values to the bindist directly in the
default.target toolchain file, and `make` writes almost nothing to
`settings` now (see #26227)
The entries deleted in this MR were already unused.
Fixes #26478
-
f7adfed2
by ARATA Mizuki at 2025-10-08T08:37:24-04:00
T22033 is only relevant if the word size is 64-bit
Fixes #25497
-
ff1650c9
by Ben Gamari at 2025-10-08T08:38:07-04:00
rts/posix: Enforce iteration limit on heap reservation logic
Previously we could loop indefinitely when attempting to get an address
space reservation for our heap. Limit the logic to 8 iterations to
ensure we instead issue a reasonable error message.
Addresses #26151.
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01844557
by Ben Gamari at 2025-10-08T08:38:07-04:00
rts/posix: Hold on to low reservations when reserving heap
Previously when the OS gave us an address space reservation in low
memory we would immediately release it and try again. However, on some
platforms this meant that we would get the same allocation again in the
next iteration (since mmap's `hint` argument is just that, a hint).
Instead we now hold on to low reservations until we have found a
suitable heap reservation.
Fixes #26151.
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b2c8d052
by Sven Tennie at 2025-10-08T08:38:47-04:00
Build terminfo only in upper stages in cross-builds (#26288)
Currently, there's no way to provide library paths for [n]curses for
both - build and target - in cross-builds. As stage0 is only used to
build upper stages, it should be fine to build terminfo only for them.
This re-enables building cross-compilers with terminfo.
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c58f9a61
by Julian Ospald at 2025-10-08T08:39:36-04:00
ghc-toolchain: Drop `ld.gold` from merge object command
It's deprecated.
Also see #25716
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2b8baada
by sheaf at 2025-10-08T18:23:37-04:00
Improvements to 'mayLookIdentical'
This commit makes significant improvements to the machinery that decides
when we should pretty-print the "invisible bits" of a type, such as:
- kind applications, e.g. '@k' in 'Proxy @k ty'
- RuntimeReps, e.g. 'TYPE r'
- multiplicities and linear arrows 'a %1 -> b'
To do this, this commit refactors 'mayLookIdentical' to return **which**
of the invisible bits don't match up, e.g. in
(a %1 -> b) ~ (a %Many -> b)
we find that the invisible bit that doesn't match up is a multiplicity,
so we should set 'sdocLinearTypes = True' when pretty-printing, and with
e.g.
Proxy @k1 ~ Proxy @k2
we find that the invisible bit that doesn't match up is an invisible
TyCon argument, so we set 'sdocPrintExplicitKinds = True'.
We leverage these changes to remove the ad-hoc treatment of linearity
of data constructors with 'dataConDisplayType' and 'dataConNonLinearType'.
This is now handled by the machinery of 'pprWithInvisibleBits'.
Fixes #26335 #26340
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129ce32d
by sheaf at 2025-10-08T18:23:37-04:00
Store SDoc context in SourceError
This commits modifies the SourceError datatype which is used for
throwing and then reporting exceptions by storing all the info we need
to be able to print the SDoc, including whether we should print with
explicit kinds, explicit runtime-reps, etc.
This is done using the new datatype:
data SourceErrorContext
= SEC
!DiagOpts
!(DiagnosticOpts GhcMessage)
Now, when we come to report an error (by handling the exception), we
have access to the full context we need.
Fixes #26387
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f9790ca8
by Ben Gamari at 2025-10-08T18:24:19-04:00
gitlab-ci: Make RELEASE_JOB an input
Rather than an undocumented variable.
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d99bb461
by Recursion Ninja at 2025-10-09T10:50:25-04:00
Do not perform MUL/DIV/REM by power of 2 optimization if the value is
outside the (signed) logical range of the Integer type's bit-width.
This fixes #25664
Minimal test case added, using the reproducer provided by @clyring:
https://gitlab.haskell.org/ghc/ghc/-/issues/25664#note_606177
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73389bcb
by Recursion Ninja at 2025-10-09T10:50:25-04:00
Changing manner in which truncation occur.