-
8d33d048
by Berk Özkütük at 2025-07-07T20:42:20-04:00
Consider `PromotedDataCon` in `tyConStupidTheta`
Haddock checks data declarations for the stupid theta so as not to
pretty-print them as empty contexts. Type data declarations end up as
`PromotedDataCon`s by the time Haddock performs this check, causing a
panic. This commit extends `tyConStupidTheta` so that it returns an
empty list for `PromotedDataCon`s. This decision was guided by the fact
that type data declarations never have data type contexts (see (R1) in
Note [Type data declarations]).
Fixes #25739.
-
a26243fd
by Ryan Hendrickson at 2025-07-07T20:43:07-04:00
haddock: Document instances from other packages
When attaching instances to `Interface`s, it isn't enough just to look
for instances in the list of `Interface`s being processed. We also need
to look in the modules on which they depend, including those outside of
this package.
Fixes #25147.
Fixes #26079.
-
0fb24420
by Rodrigo Mesquita at 2025-07-07T20:43:49-04:00
hadrian: Fallback logic for internal interpreter
When determining whether to build the internal interpreter, the `make`
build system had a fallback case for platforms not in the list of
explicitly-supported operating systems and architectures.
This fallback says we should try to build the internal interpreter if
building dynamic GHC programs (if the architecture is unknown).
Fixes #24098
-
fe925bd4
by Ben Gamari at 2025-07-07T20:44:30-04:00
users-guide: Reference Wasm FFI section
-
5856284b
by Ben Gamari at 2025-07-07T20:44:30-04:00
users-guide: Fix too-short heading warning
-
a48dcdf3
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Reorganise documentation for allocate* functions
Consolodate interface information into the .h file, keeping just
implementation details in the .c file.
Use Notes stlye in the .h file and refer to notes from the .c file.
-
de5b528c
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Introduce common utilities for allocating arrays
The intention is to share code among the several places that do this
already.
-
b321319d
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Use new array alloc utils in Heap.c
The CMM primop can now report heap overflow.
-
1d557ffb
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Use new array alloc utils in ThreadLabels.c
Replacing a local utility.
-
e59a1430
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Use new array alloc utils in Threads.c
Replacing local open coded version.
-
482df1c9
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Add exitHeapOverflow helper utility
This will be useful with the array alloc functions, since unlike
allocate/allocateMaybeFail, they do not come in two versions. So if it's
not convenient to propagate failure, then one can use this.
-
4d3ec8f9
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Use new array alloc utils in Weak.c
Also add a cpp macro CCS_SYSTEM_OR_NULL which does what it says. The
benefit of this is that it allows us to referece CCS_SYSTEM even when
we're not in PROFILING mode. That makes abstracting over profiling vs
normal mode a lot easier.
-
0c4f2fde
by Duncan Coutts at 2025-07-07T20:45:18-04:00
Convert the array alloc primops to use the new array alloc utils
-
a3354ad9
by Duncan Coutts at 2025-07-07T20:45:18-04:00
While we're at it, add one missing 'likely' hint
To a cmm primops that raises an exception, like the others now do.
-
33b546bd
by meooow25 at 2025-07-07T20:46:09-04:00
Keep scanl' strict in the head on rewrite
`scanl'` forces elements to WHNF when the corresponding `(:)`s are
forced. The rewrite rule for `scanl'` missed forcing the first element,
which is fixed here with a `seq`.
-
8a69196e
by Rodrigo Mesquita at 2025-07-08T07:39:47-04:00
debugger/rts: Allow toggling step-in per thread
The RTS global flag `rts_stop_next_breakpoint` globally sets the
interpreter to stop at the immediate next breakpoint.
With this commit, single step mode can additionally be set per thread in
the TSO flag (TSO_STOP_NEXT_BREAKPOINT).
Being able to toggle "stop at next breakpoint" per thread is an
important requirement for implementing "stepping out" of a function in a
multi-threaded context.
And, more generally, having a per-thread flag for single-stepping paves the
way for multi-threaded debugging.
That said, when we want to enable "single step" mode for the whole
interpreted program we still want to stop at the immediate next
breakpoint, whichever thread it belongs to.
That's why we also keep the global `rts_stop_next_breakpoint` flag, with
`rts_enableStopNextBreakpointAll` and `rts_disableStopNextBreakpointAll` helpers.
Preparation for #26042
-
73d3f864
by Rodrigo Mesquita at 2025-07-08T07:39:47-04:00
docs: Case continuation BCOs
This commit documents a subtle interaction between frames for case BCOs
and their parents frames. Namely, case continuation BCOs may refer to
(non-local) variables that are part of the parent's frame.
The note expanding a bit on these details is called [Case continuation BCOs]
-
d7aeddcf
by Rodrigo Mesquita at 2025-07-08T07:39:47-04:00
debugger: Implement step-out feature
Implements support for stepping-out of a function (aka breaking right after
returning from a function) in the interactive debugger.
It also introduces a GHCi command :stepout to step-out of a function
being debugged in the interpreter. The feature is described as:
Stop at the first breakpoint immediately after returning from the current
function scope.
Known limitations: because a function tail-call does not push a stack
frame, if step-out is used inside of a function that was tail-called,
execution will not be returned to its caller, but rather its caller's
first non-tail caller. On the other hand, it means the debugger
follows the more realistic execution of the program.
In the following example:
.. code-block:: none
f = do
a
b <--- (1) set breakpoint then step in here
c
b = do
...
d <--- (2) step-into this tail call
d = do
...
something <--- (3) step-out here
...
Stepping-out will stop execution at the `c` invokation in `f`, rather than
stopping at `b`.
The key idea is simple: When step-out is enabled, traverse the runtime
stack until a continuation BCO is found -- and enable the breakpoint
heading that BCO explicitly using its tick-index.
The details are specified in `Note [Debugger: Step-out]` in `rts/Interpreter.c`.
Since PUSH_ALTS BCOs (representing case continuations) were never headed
by a breakpoint (unlike the case alternatives they push), we introduced
the BRK_ALTS instruction to allow the debugger to set a case
continuation to stop at the breakpoint heading the alternative that is
taken. This is further described in `Note [Debugger: BRK_ALTS]`.
Fixes #26042
-
5d9adf51
by Rodrigo Mesquita at 2025-07-08T07:39:47-04:00
debugger: Filter step-out stops by SrcSpan
To implement step-out, the RTS looks for the first continuation frame on
the stack and explicitly enables its entry breakpoint. However, some
continuations will be contained in the function from which step-out was
initiated (trivial example is a case expression).
Similarly to steplocal, we will filter the breakpoints at which the RTS
yields to the debugger based on the SrcSpan. When doing step-out, only
stop if the breakpoint is /not/ contained in the function from which we
initiated it.
This is especially relevant in monadic statements such as IO which is
compiled to a long chain of case expressions.
See Note [Debugger: Filtering step-out stops]
-
7677adcc
by Cheng Shao at 2025-07-08T07:40:29-04:00
compiler: make ModBreaks serializable
-
14f67c6d
by Rodrigo Mesquita at 2025-07-08T07:40:29-04:00
refactor: "Inspecting the session" moved from GHC
Moved utilities for inspecting the session from the GHC module to
GHC.Driver.Session.Inspect
Purely a clean up
-
9d3f484a
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
cleanup: Pass the HUG to readModBreaks, not HscEnv
A minor cleanup. The associated history and setupBreakpoint functions
are changed accordingly.
-
b595f713
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
cleanup: Move readModBreaks to GHC.Runtime.Interpreter
With some small docs changes
-
d223227a
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
cleanup: Move interpreterProfiled to Interp.Types
Moves interpreterProfiled and interpreterDynamic to
GHC.Runtime.Interpreter.Types from GHC.Runtime.Interpreter.
-
7fdd0a3d
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
cleanup: Don't import GHC in Debugger.Breakpoints
Remove the top-level
import GHC
from GHC.Runtime.Debugger.Breakpoints
This makes the module dependencies more granular and cleans up the
qualified imports from the code.
-
5e4da31b
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
refactor: Use BreakpointId in Core and Ifaces
-
741ac3a8
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
stg2bc: Derive BcM via ReaderT StateT
A small refactor that simplifies GHC.StgToByteCode by deriving-via the
Monad instances for BcM. This is done along the lines of previous
similar refactors like 72b54c0760bbf85be1f73c1a364d4701e5720465.
-
0414fcc9
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
refact: Split InternalModBreaks out of ModBreaks
There are currently two competing ways of referring to a Breakpoint:
1. Using the Tick module + Tick index
2. Using the Info module + Info index
1. The Tick index is allocated during desugaring in `mkModBreaks`. It is
used to refer to a breakpoint associated to a Core Tick. For a given
Tick module, there are N Ticks indexed by Tick index.
2. The Info index is allocated during code generation (in StgToByteCode)
and uniquely identifies the breakpoints at runtime (and is indeed used
to determine which breakpoint was hit at runtime).
Why we need both is described by Note [Breakpoint identifiers].
For every info index we used to keep a `CgBreakInfo`, a datatype containing
information relevant to ByteCode Generation, in `ModBreaks`.
This commit splits out the `IntMap CgBreakInfo` out of `ModBreaks` into
a new datatype `InternalModBreaks`.
- The purpose is to separate the `ModBreaks` datatype, which stores
data associated from tick-level information which is fixed after
desugaring, from the unrelated `IntMap CgBreakInfo` information
accumulated during bytecode generation.
- We move `ModBreaks` to GHC.HsToCore.Breakpoints
The new `InternalModBreaks` simply combines the `IntMap CgBreakInfo`
with `ModBreaks`. After code generation we construct an
`InternalModBreaks` with the `CgBreakInfo`s we accumulated and the
existing `ModBreaks` and store that in the compiled BCO in `bc_breaks`.
- Note that we previously only updated the `modBreaks_breakInfo`
field of `ModBreaks` at this exact location, and then stored the
updated `ModBreaks` in the same `bc_breaks`.
- We put this new datatype in GHC.ByteCode.Breakpoints
The rest of the pipeline for which CgBreakInfo is relevant is
accordingly updated to also use `InternalModBreaks`
-
2a097955
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
cleanup: Use BreakpointIds in bytecode gen
Small clean up to use BreakpointId and InternalBreakpointId more
uniformly in bytecode generation rather than using Module + Ix pairs
-
0515cc2f
by Rodrigo Mesquita at 2025-07-08T07:40:30-04:00
ghci: Allocate BreakArrays at link time only
Previously, a BreakArray would be allocated with a slot for every tick
in a module at `mkModBreaks`, in HsToCore. However, this approach has
a few downsides:
- It interleaves interpreter behaviour (allocating arrays for
breakpoints) within the desugarer
- It is inflexible in the sense it is impossible for the bytecode
generator to add "internal" breakpoints that can be triggered at
runtime, because those wouldn't have a source tick. (This is relevant
for our intended implementation plan of step-out in #26042)
- It ties the BreakArray indices to the *tick* indexes, while at runtime
we would rather just have the *info* indexes (currently we have both
because BreakArrays are indexed by the *tick* one).
Paving the way for #26042 and #26064, this commit moves the allocation
of BreakArrays to bytecode-loading time -- akin to what is done for CCS
arrays.
Since a BreakArray is allocated only when bytecode is linked, if a
breakpoint is set (e.g. `:break 10`) before the bytecode is linked,
there will exist no BreakArray to trigger the breakpoint in.
Therefore, the function to allocate break arrays (`allocateBreakArrays`)
is exposed and also used in GHC.Runtime.Eval to allocate a break array
when a breakpoint is set, if it doesn't exist yet (in the linker env).
-
8016561f
by Simon Peyton Jones at 2025-07-08T07:41:13-04:00
Add a test for T26176
-
454cd682
by Simon Peyton Jones at 2025-07-08T07:41:13-04:00
Add test for #14010
This test started to work in GHC 9.6 and has worked since.
This MR just adds a regression test
-
ea2c6673
by Teo Camarasu at 2025-07-08T13:24:43-04:00
Implement user-defined allocation limit handlers
Allocation Limits allow killing a thread if they allocate more than a
user-specified limit.
We extend this feature to allow more versatile behaviour.
- We allow not killing the thread if the limit is exceeded.
- We allow setting a custom handler to be called when the limit is exceeded.
User-specified allocation limit handlers run in a fresh thread and are passed
the ThreadId of the thread that exceeded its limit.
We introduce utility functions for getting and setting the allocation
limits of other threads, so that users can reset the limit of a thread
from a handler. Both of these are somewhat coarse-grained as we are
unaware of the allocations in the current nursery chunk.
We provide several examples of usages in testsuite/tests/rts/T22859.hs
Resolves #22859
-
03e047f9
by Simon Hengel at 2025-07-08T13:25:25-04:00
Fix typo in using.rst
-
67957854
by Ben Gamari at 2025-07-09T09:44:44-04:00
compiler: Import AnnotationWrapper from ghc-internal
Since `GHC.Desugar` exported from `base` has been deprecated.
-
813d99d6
by Ben Gamari at 2025-07-09T09:44:44-04:00
ghc-compact: Eliminate dependency on ghc-prim
-
0ec952a1
by Ben Gamari at 2025-07-09T09:44:44-04:00
ghc-heap: Eliminate dependency on ghc-prim
-
480074c3
by Ben Gamari at 2025-07-09T09:44:44-04:00
ghc-heap: Drop redundant import
-
03455829
by Ben Gamari at 2025-07-09T09:44:45-04:00
ghc-prim: Bump version to 0.13.1
There are no interface changes from 0.13.0 but the implementation now
lives in `ghc-internal`.
-
d315345a
by Ben Gamari at 2025-07-09T09:44:45-04:00
template-haskell: Bump version number to 2.24.0.0
Bumps exceptions submodule.
-
004c800e
by Ben Gamari at 2025-07-09T09:44:45-04:00
Bump GHC version number to 9.14
-
eb1a3816
by Ben Gamari at 2025-07-09T09:44:45-04:00
Bump parsec to 3.1.18.0
Bumps parsec submodule.
-
86f83296
by Ben Gamari at 2025-07-09T09:44:45-04:00
unix: Bump to 2.8.7.0
Bumps unix submodule.
-
89e13998
by Ben Gamari at 2025-07-09T09:44:45-04:00
binary: Bump to 0.8.9.3
Bumps binary submodule.
-
55fff191
by Ben Gamari at 2025-07-09T09:44:45-04:00
Win32: Bump to 2.14.2.0
Bumps Win32 submodule.
-
7dafa40c
by Ben Gamari at 2025-07-09T09:44:45-04:00
base: Bump version to 4.22.0
Bumps various submodules.
-
ef03d8b8
by Rodrigo Mesquita at 2025-07-09T09:45:28-04:00
base: Export displayExceptionWithInfo
This function should be exposed from base following CLC#285
Approved change in CLC#344
Fixes #26058
-
01d3154e
by Wen Kokke at 2025-07-10T17:06:36+01:00
Fix documentation for HEAP_PROF_SAMPLE_STRING
-
ac259c48
by Wen Kokke at 2025-07-10T17:06:38+01:00
Fix documentation for HEAP_PROF_SAMPLE_COST_CENTRE
-
2b4db9ba
by Pi Delport at 2025-07-11T16:40:52-04:00
(Applicative docs typo: missing "one")
-
f707bab4
by Andreas Klebinger at 2025-07-12T14:56:16+01:00
Specialise: Improve specialisation by refactoring interestingDict
This MR addresses #26051, which concerns missed type-class specialisation.
The main payload of the MR is to completely refactor the key function
`interestingDict` in GHC.Core.Opt.Specialise
The main change is that we now also look at the structure of the
dictionary we consider specializing on, rather than only the type.
See the big `Note [Interesting dictionary arguments]`
-
ca7a9d42
by Simon Peyton Jones at 2025-07-12T14:56:16+01:00
Treat tuple dictionaries uniformly; don't unbox them
See `Note [Do not unbox class dictionaries]` in DmdAnal.hs,
sep (DNB1).
This MR reverses the plan in #23398, which suggested a special case to
unbox tuple dictionaries in worker/wrapper. But:
- This was the cause of a pile of complexity in the specialiser (#26158)
- Even with that complexity, specialision was still bad, very bad
See https://gitlab.haskell.org/ghc/ghc/-/issues/19747#note_626297
And it's entirely unnecessary! Specialision works fine without
unboxing tuple dictionaries.
-
be7296c9
by Andreas Klebinger at 2025-07-12T14:56:16+01:00
Remove complex special case from the type-class specialiser
There was a pretty tricky special case in Specialise which is no
longer necessary.
* Historical Note [Floating dictionaries out of cases]
* #26158
* #19747 https://gitlab.haskell.org/ghc/ghc/-/issues/19747#note_626297
This MR removes it. Hooray.
-
4acf3a86
by Ben Gamari at 2025-07-15T05:46:32-04:00
configure: bump version to 9.15
-
45efaf71
by Teo Camarasu at 2025-07-15T05:47:13-04:00
rts/nonmovingGC: remove n_free
We remove the nonmovingHeap.n_free variable.
We wanted this to track the length of nonmovingHeap.free.
But this isn't possible to do atomically.
When this isn't accurate we can get a segfault by going past the end of
the list.
Instead, we just count the length of the list when we grab it in
nonmovingPruneFreeSegment.
Resolves #26186
-
c635f164
by Ben Gamari at 2025-07-15T14:05:54-04:00
configure: Drop probing of ld.gold
As noted in #25716, `gold` has been dropped from binutils-2.44.
Fixes #25716.
Metric Increase:
size_hello_artifact_gzip
size_hello_unicode_gzip
ghc_prim_so
-
637bb538
by Ben Gamari at 2025-07-15T14:05:55-04:00
testsuite/recomp015: Ignore stderr
This is necessary since ld.bfd complains
that we don't have a .note.GNU-stack section,
potentially resulting in an executable stack.
-
d3cd4ec8
by Wen Kokke at 2025-07-15T14:06:39-04:00
Fix documentation for heap profile ID
-
73082769
by Ben Gamari at 2025-07-15T16:56:38-04:00
Bump win32-tarballs to v0.9
-
3b63b254
by Ben Gamari at 2025-07-15T16:56:39-04:00
rts/LoadArchive: Handle null terminated string tables
As of `llvm-ar` now emits filename tables terminated with null
characters instead of the usual POSIX `/\n` sequence.
Fixes #26150.
-
195f6527
by Tamar Christina at 2025-07-15T16:56:39-04:00
rts: rename label so name doesn't conflict with param
-
63373b95
by Tamar Christina at 2025-07-15T16:56:39-04:00
rts: Handle API set symbol versioning conflicts
-
48e9aa3e
by Tamar Christina at 2025-07-15T16:56:39-04:00
rts: Mark API set symbols as HIDDEN and correct symbol type
-
959e827a
by Tamar Christina at 2025-07-15T16:56:39-04:00
rts: Implement WEAK EXTERNAL undef redirection by target symbol name
-
65f19293
by Ben Gamari at 2025-07-15T16:56:39-04:00
rts/LoadArchive: Handle string table entries terminated with /
llvm-ar appears to terminate string table entries with `/\n` [1]. This
matters in the case of thin archives, since the filename is used. In the
past this worked since `llvm-ar` would produce archives with "small"
filenames when possible. However, now it appears to always use the
string table.
[1] https://github.com/llvm/llvm-project/blob/bfb686bb5ba503e9386dc899e1ebbe2488e6a0a8/llvm/lib/Object/ArchiveWriter.cpp#L314
-
9cbb3ef5
by Ben Gamari at 2025-07-15T16:56:39-04:00
testsuite: Mark T12497 as fixed
Thanks to the LLVM toolchain update.
Closes #22694.
-
2854407e
by Ben Gamari at 2025-07-15T16:56:39-04:00
testsuite: Accept new output of T11223_link_order_a_b_2_fail on Windows
The archive member number changed due to the fact that llvm-ar now uses a
string table.
-
28439593
by Ben Gamari at 2025-07-15T16:56:39-04:00
rts/linker/PEi386: Implement IMAGE_REL_AMD64_SECREL
This appears to now be used by libc++ as distributed by msys2.
-
2b053755
by Tamar Christina at 2025-07-15T16:56:39-04:00
rts: Cleanup merge resolution residue in lookupSymbolInDLL_PEi386 and make safe without dependent
-
e8acd2e7
by Wen Kokke at 2025-07-16T08:37:04-04:00
Remove the `profile_id` parameter from various RTS functions.
Various RTS functions took a `profile_id` parameter, intended to be used to
distinguish parallel heap profile breakdowns (e.g., `-hT` and `-hi`). However,
this feature was never implemented and the `profile_id` parameter was set to 0
throughout the RTS. This commit removes the parameter but leaves the hardcoded
profile ID in the functions that emit the encoded eventlog events as to not
change the protocol.
The affected functions are `traceHeapProfBegin`, `postHeapProfBegin`,
`traceHeapProfSampleString`, `postHeapProfSampleString`,
`traceHeapProfSampleCostCentre`, and `postHeapProfSampleCostCentre`.
-
76d392a2
by Wen Kokke at 2025-07-16T08:37:04-04:00
Make `traceHeapProfBegin` an init event.
-
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
-
3a09cd06
by Matthew Pickering at 2025-07-22T04:32:16+02:00
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