[Git][ghc/ghc][wip/warning-for-last-and-init] 65 commits: Specialise: Improve specialisation by refactoring interestingDict

Bodigrim pushed to branch wip/warning-for-last-and-init at Glasgow Haskell Compiler / GHC Commits: 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/bfb686bb5ba503e9386dc899e1ebbe2488... - - - - - 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 - - - - - 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 . - 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 - - - - - d79bc713 by Mike Pilgrem at 2025-08-05T23:40:41+01:00 Re CLC issue 292 Warn GHC.Internal.List.{init,last} are partial Also corrects the warning for `tail` to refer to `Data.List.uncons` (like the existing warning for `head`). In module `Settings.Warnings`, applies `-Wno-unrecognised-warning-flags` `-Wno-x-partial` to the `Cabal`, `filepath`, `hsc2hs`, `hpc`, `parsec`, `text` and `time` packages (outside GHC's repository). - - - - - 241 changed files: - .gitlab/rel_eng/fetch-gitlab-artifacts/fetch_gitlab.py - compiler/GHC/ByteCode/Asm.hs - compiler/GHC/ByteCode/Breakpoints.hs - compiler/GHC/ByteCode/Instr.hs - compiler/GHC/ByteCode/Linker.hs - compiler/GHC/ByteCode/Types.hs - compiler/GHC/CmmToAsm/LA64/CodeGen.hs - compiler/GHC/CmmToAsm/LA64/Instr.hs - compiler/GHC/CmmToAsm/LA64/Ppr.hs - compiler/GHC/CmmToAsm/X86/CodeGen.hs - compiler/GHC/CmmToAsm/X86/Instr.hs - compiler/GHC/CmmToAsm/X86/Ppr.hs - compiler/GHC/Core.hs - compiler/GHC/Core/FVs.hs - compiler/GHC/Core/LateCC/OverloadedCalls.hs - compiler/GHC/Core/Make.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/CprAnal.hs - compiler/GHC/Core/Opt/DmdAnal.hs - compiler/GHC/Core/Opt/Monad.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap/Utils.hs - compiler/GHC/Core/Predicate.hs - compiler/GHC/Core/Rules.hs - compiler/GHC/Core/Subst.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/Unfold/Make.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/CoreToIface.hs - compiler/GHC/Driver/CmdLine.hs - compiler/GHC/Driver/Errors.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Driver/Make.hs - compiler/GHC/Driver/Session/Units.hs - compiler/GHC/Hs/ImpExp.hs - compiler/GHC/HsToCore/Binds.hs - compiler/GHC/HsToCore/Breakpoints.hs - compiler/GHC/HsToCore/Errors/Ppr.hs - compiler/GHC/HsToCore/Pmc/Solver/Types.hs - compiler/GHC/Iface/Ext/Ast.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Parser.y - compiler/GHC/Prelude/Basic.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Runtime/Debugger/Breakpoints.hs - compiler/GHC/Runtime/Eval.hs - compiler/GHC/Runtime/Interpreter.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/SysTools/Process.hs - compiler/GHC/SysTools/Tasks.hs - compiler/GHC/Tc/Deriv.hs - compiler/GHC/Tc/Deriv/Infer.hs - compiler/GHC/Tc/Deriv/Utils.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Errors/Ppr.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Sig.hs - compiler/GHC/Tc/Solver.hs - compiler/GHC/Tc/Solver/Default.hs - compiler/GHC/Tc/Solver/Dict.hs - compiler/GHC/Tc/Solver/Equality.hs - compiler/GHC/Tc/Solver/InertSet.hs - compiler/GHC/Tc/Solver/Monad.hs - compiler/GHC/Tc/Solver/Rewrite.hs - compiler/GHC/Tc/Solver/Solve.hs - + compiler/GHC/Tc/Solver/Solve.hs-boot - compiler/GHC/Tc/Solver/Types.hs - compiler/GHC/Tc/TyCl/PatSyn.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Evidence.hs - compiler/GHC/Tc/Types/Origin.hs - compiler/GHC/Tc/Utils/Monad.hs - compiler/GHC/Tc/Utils/TcMType.hs - compiler/GHC/Tc/Utils/TcType.hs - compiler/GHC/Tc/Utils/Unify.hs - compiler/GHC/Tc/Validity.hs - compiler/GHC/Tc/Zonk/Type.hs - compiler/GHC/Types/Error.hs - compiler/GHC/Types/Name/Cache.hs - compiler/GHC/Types/Var.hs - compiler/GHC/Unit/Module/Graph.hs - compiler/GHC/Utils/Error.hs - compiler/GHC/Utils/Logger.hs - configure.ac - docs/users_guide/9.14.1-notes.rst - + docs/users_guide/diagnostics-as-json-schema-1_2.json - docs/users_guide/eventlog-formats.rst - docs/users_guide/profiling.rst - docs/users_guide/runtime_control.rst - docs/users_guide/using-optimisation.rst - docs/users_guide/using.rst - docs/users_guide/win32-dlls.rst - ghc/GHCi/UI.hs - ghc/GHCi/UI/Monad.hs - ghc/Main.hs - hadrian/src/Settings/Warnings.hs - hadrian/stack.yaml - hadrian/stack.yaml.lock - libraries/Cabal - libraries/base/changelog.md - libraries/base/src/Control/Exception/Backtrace.hs - libraries/base/src/Data/List/NonEmpty.hs - libraries/base/src/GHC/Generics.hs - libraries/base/src/GHC/Weak/Finalize.hs - libraries/filepath - libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs - libraries/ghc-internal/src/GHC/Internal/Data/OldList.hs - libraries/ghc-internal/src/GHC/Internal/Float.hs - libraries/ghc-internal/src/GHC/Internal/List.hs - libraries/ghc-internal/src/GHC/Internal/Real.hs - libraries/ghc-internal/src/GHC/Internal/System/IO.hs - libraries/ghc-internal/src/GHC/Internal/TH/Syntax.hs - libraries/ghci/GHCi/Debugger.hs - libraries/ghci/GHCi/Message.hs - libraries/ghci/GHCi/Run.hs - libraries/template-haskell/vendored-filepath/System/FilePath/Posix.hs - libraries/template-haskell/vendored-filepath/System/FilePath/Windows.hs - m4/find_ld.m4 - mk/get-win32-tarballs.py - rts/Disassembler.c - rts/Exception.cmm - rts/Interpreter.c - rts/PrimOps.cmm - rts/ProfHeap.c - rts/RaiseAsync.c - rts/RetainerSet.c - rts/RtsFlags.c - rts/STM.c - rts/Timer.c - rts/Trace.c - rts/Trace.h - rts/eventlog/EventLog.c - rts/eventlog/EventLog.h - rts/include/rts/Flags.h - rts/linker/LoadArchive.c - rts/linker/PEi386.c - rts/sm/NonMoving.c - rts/sm/NonMoving.h - rts/sm/NonMovingAllocate.c - rts/sm/Sanity.c - testsuite/tests/corelint/T21115b.stderr - + testsuite/tests/cpranal/sigs/T25944.hs - + testsuite/tests/cpranal/sigs/T25944.stderr - testsuite/tests/cpranal/sigs/all.T - testsuite/tests/deriving/should_compile/T20815.hs - testsuite/tests/deriving/should_fail/T12768.stderr - testsuite/tests/deriving/should_fail/T1496.stderr - testsuite/tests/deriving/should_fail/T5498.stderr - testsuite/tests/deriving/should_fail/T7148.stderr - testsuite/tests/deriving/should_fail/T7148a.stderr - testsuite/tests/dmdanal/should_compile/T23398.hs - testsuite/tests/dmdanal/should_compile/T23398.stderr - testsuite/tests/driver/j-space/jspace.hs - testsuite/tests/driver/json.stderr - testsuite/tests/driver/json_warn.stderr - testsuite/tests/driver/recomp015/all.T - testsuite/tests/haddock/haddock_testsuite/Makefile - + testsuite/tests/haddock/haddock_testsuite/T26114.hs - + testsuite/tests/haddock/haddock_testsuite/T26114.stdout - testsuite/tests/haddock/haddock_testsuite/all.T - testsuite/tests/hiefile/should_run/HieQueries.stdout - testsuite/tests/hiefile/should_run/TestUtils.hs - testsuite/tests/impredicative/T17332.stderr - testsuite/tests/interface-stability/base-exports.stdout - testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs - testsuite/tests/interface-stability/base-exports.stdout-mingw32 - testsuite/tests/interface-stability/base-exports.stdout-ws-32 - + testsuite/tests/lib/stm/T26028.hs - + testsuite/tests/lib/stm/T26028.stdout - + testsuite/tests/lib/stm/all.T - testsuite/tests/numeric/should_run/T9810.stdout - + testsuite/tests/perf/should_run/SpecTyFamRun.hs - + testsuite/tests/perf/should_run/SpecTyFamRun.stdout - + testsuite/tests/perf/should_run/SpecTyFam_Import.hs - testsuite/tests/perf/should_run/all.T - testsuite/tests/printer/Makefile - + testsuite/tests/printer/TestLevelImports.hs - + testsuite/tests/printer/TestNamedDefaults.hs - testsuite/tests/printer/all.T - testsuite/tests/quantified-constraints/T15290a.stderr - testsuite/tests/quantified-constraints/T19690.stderr - testsuite/tests/quantified-constraints/T19921.stderr - testsuite/tests/quantified-constraints/T21006.stderr - testsuite/tests/roles/should_fail/RolesIArray.stderr - testsuite/tests/rts/KeepCafsBase.hs - testsuite/tests/rts/all.T - testsuite/tests/rts/flags/all.T - testsuite/tests/rts/linker/T11223/T11223_link_order_a_b_2_fail.stderr-ws-32-mingw32 - testsuite/tests/rts/linker/T11223/T11223_link_order_a_b_2_fail.stderr-ws-64-mingw32 - testsuite/tests/simd/should_run/all.T - + testsuite/tests/simd/should_run/doublex2_shuffle.hs - + testsuite/tests/simd/should_run/doublex2_shuffle.stdout - + testsuite/tests/simd/should_run/doublex2_shuffle_baseline.hs - + testsuite/tests/simd/should_run/doublex2_shuffle_baseline.stdout - + testsuite/tests/simd/should_run/floatx4_shuffle.hs - + testsuite/tests/simd/should_run/floatx4_shuffle.stdout - + testsuite/tests/simd/should_run/floatx4_shuffle_baseline.hs - + testsuite/tests/simd/should_run/floatx4_shuffle_baseline.stdout - + testsuite/tests/simplCore/should_compile/T26051.hs - + testsuite/tests/simplCore/should_compile/T26051.stderr - + testsuite/tests/simplCore/should_compile/T26051_Import.hs - + testsuite/tests/simplCore/should_compile/T26115.hs - + testsuite/tests/simplCore/should_compile/T26115.stderr - + testsuite/tests/simplCore/should_compile/T26116.hs - + testsuite/tests/simplCore/should_compile/T26116.stderr - + testsuite/tests/simplCore/should_compile/T26117.hs - + testsuite/tests/simplCore/should_compile/T26117.stderr - testsuite/tests/simplCore/should_compile/all.T - + testsuite/tests/splice-imports/T26087.stderr - + testsuite/tests/splice-imports/T26087A.hs - + testsuite/tests/splice-imports/T26087B.hs - + testsuite/tests/splice-imports/T26088.stderr - + testsuite/tests/splice-imports/T26088A.hs - + testsuite/tests/splice-imports/T26088B.hs - testsuite/tests/splice-imports/all.T - testsuite/tests/typecheck/should_compile/T12427a.stderr - testsuite/tests/typecheck/should_compile/T23171.hs - testsuite/tests/typecheck/should_compile/TcSpecPragmas.stderr - testsuite/tests/typecheck/should_fail/T14605.hs - testsuite/tests/typecheck/should_fail/T14605.stderr - testsuite/tests/typecheck/should_fail/T15801.stderr - testsuite/tests/typecheck/should_fail/T18640a.stderr - testsuite/tests/typecheck/should_fail/T18640b.stderr - testsuite/tests/typecheck/should_fail/T19627.stderr - testsuite/tests/typecheck/should_fail/T21530b.stderr - testsuite/tests/typecheck/should_fail/T22912.stderr - testsuite/tests/typecheck/should_fail/tcfail174.stderr - utils/check-exact/ExactPrint.hs - utils/check-exact/Utils.hs - utils/ghc-pkg/Main.hs - utils/ghc-toolchain/src/GHC/Toolchain/CheckArm.hs - utils/ghc-toolchain/src/GHC/Toolchain/Tools/Link.hs - utils/haddock/haddock-api/haddock-api.cabal - utils/haddock/haddock-api/src/Haddock/Backends/Xhtml.hs - utils/haddock/haddock-api/src/Haddock/Interface/Rename.hs - utils/haddock/haddock-library/src/Documentation/Haddock/Parser.hs - utils/hpc - utils/hsc2hs The diff was not included because it is too large. View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/dfabdcc0be64c68d200e25614ab6391... -- View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/dfabdcc0be64c68d200e25614ab6391... You're receiving this email because of your account on gitlab.haskell.org.