Simon Peyton Jones pushed to branch wip/T26255 at Glasgow Haskell Compiler / GHC Commits: 37655c46 by Teo Camarasu at 2025-08-26T15:24:51-04:00 tests: disable T22859 under LLVM This test was failing under the LLVM backend since the allocations differ from the NCG. Resolves #26282 - - - - - 2cbba9d6 by Teo Camarasu at 2025-08-26T15:25:33-04:00 base-exports: update version numbers As the version of the compiler has been bumped, a lot of the embedded version numbers will need to be updated if we ever run this test with `--test-accept` so let's just update them now, and keep future diffs clean. - - - - - f9f2ffcf by Alexandre Esteves at 2025-08-27T07:19:14-04:00 Import new name for 'utimbuf' on windows to fix #26337 Fixes an `-Wincompatible-pointer-types` instance that turns into an error on recent toolchains and surfaced as such on nixpkgs when doing linux->ucrt cross. This long-standing warning has been present at least since 9.4: ``` C:\GitLabRunner\builds\0\1709189\tmp\ghc16652_0\ghc_4.c:26:115: error: warning: incompatible pointer types passing 'struct utimbuf *' to parameter of type 'struct _utimbuf *' [-Wincompatible-pointer-types] | 26 | HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);} | ^ HsInt32 ghczuwrapperZC9ZCbaseZCSystemziPosixziInternalsZCzuutime(char* a1, struct utimbuf* a2) {return _utime(a1, a2);} ^~ C:\GitLabRunner\builds\0\1709189\_build\stage0\lib\..\..\mingw\x86_64-w64-mingw32\include\sys\utime.h:109:72: error: note: passing argument to parameter '_Utimbuf' here | 109 | __CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) { | ^ __CRT_INLINE int __cdecl _utime(const char *_Filename,struct _utimbuf *_Utimbuf) { ``` - - - - - ae89f000 by Hassan Al-Awwadi at 2025-08-27T07:19:56-04:00 Adds the fucnction addDependentDirectory to Q, resolving issue #26148. This function adds a new directory to the list of things a module depends upon. That means that when the contents of the directory change, the recompilation checker will notice this and the module will be recompiled. Documentation has also been added for addDependentFunction and addDependentDirectory in the user guide. - - - - - 00478944 by Simon Peyton Jones at 2025-08-27T16:48:30+01:00 Comments only - - - - - a7884589 by Simon Peyton Jones at 2025-08-28T11:08:23+01:00 Type-family occurs check in unification The occurs check in `GHC.Core.Unify.uVarOrFam` was inadequate in dealing with type families. Better now. See Note [The occurs check in the Core unifier]. As I did this I realised that the whole apartness thing is trickier than I thought: see the new Note [Shortcomings of the apartness test] - - - - - 8adfc222 by sheaf at 2025-08-28T19:47:17-04:00 Fix orientation in HsWrapper composition (<.>) This commit fixes the order in which WpCast HsWrappers are composed, fixing a bug introduced in commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1. Fixes #26350 - - - - - eb2ab1e2 by Oleg Grenrus at 2025-08-29T11:00:53-04:00 Generalise thNameToGhcName by adding HasHscEnv There were multiple single monad-specific `getHscEnv` across codebase. HasHscEnv is modelled on HasDynFlags. My first idea was to simply add thNameToGhcNameHsc and thNameToGhcNameTc, but those would been exactly the same as thNameToGhcName already. Also add an usage example to thNameToGhcName and mention that it's recommended way of looking up names in GHC plugins - - - - - 2d575a7f by fendor at 2025-08-29T11:01:36-04:00 configure: Bump minimal bootstrap GHC version to 9.10 - - - - - 716274a5 by Simon Peyton Jones at 2025-08-29T17:27:12-04:00 Fix deep subsumption again This commit fixed #26255: commit 56b32c5a2d5d7cad89a12f4d74dc940e086069d1 Author: sheaf <sam.derbyshire@gmail.com> Date: Mon Aug 11 15:50:47 2025 +0200 Improve deep subsumption This commit improves the DeepSubsumption sub-typing implementation in GHC.Tc.Utils.Unify.tc_sub_type_deep by being less eager to fall back to unification. But alas it still wasn't quite right for view patterns: #26331 This MR does a generalisation to fix it. A bit of a sledgehammer to crack a nut, but nice. * Add a field `ir_inst :: InferInstFlag` to `InferResult`, where ``` data InferInstFlag = IIF_Sigma | IIF_ShallowRho | IIF_DeepRho ``` * The flag says exactly how much `fillInferResult` should instantiate before filling the hole. * We can also use this to replace the previous very ad-hoc `tcInferSigma` that was used to implement GHCi's `:type` command. - - - - - 27206c5e by sheaf at 2025-08-29T17:28:14-04:00 Back-compat for TH SpecialiseP data-con of Pragma This commit improves the backwards-compatibility story for the SpecialiseP constructor of the Template Haskell 'Pragma' datatype. Instead of keeping the constructor but deprecating it, this commit makes it into a bundled pattern synonym of the Pragma datatype. We no longer deprecate it; it's useful for handling old-form specialise pragmas. - - - - - 26dbcf61 by fendor at 2025-08-30T05:10:08-04:00 Move stack decoding logic from ghc-heap to ghc-internal The stack decoding logic in `ghc-heap` is more sophisticated than the one currently employed in `CloneStack`. We want to use the stack decoding implementation from `ghc-heap` in `base`. We cannot simply depend on `ghc-heap` in `base` due do bootstrapping issues. Thus, we move the code that is necessary to implement stack decoding to `ghc-internal`. This is the right location, as we don't want to add a new API to `base`. Moving the stack decoding logic and re-exposing it in ghc-heap is insufficient, though, as we have a dependency cycle between. * ghc-heap depends on stage1:ghc-internal * stage0:ghc depends on stage0:ghc-heap To fix this, we remove ghc-heap from the set of `stage0` dependencies. This is not entirely straight-forward, as a couple of boot dependencies, such as `ghci` depend on `ghc-heap`. Luckily, the boot compiler of GHC is now >=9.10, so we can migrate `ghci` to use `ghc-internal` instead of `ghc-heap`, which already exports the relevant modules. However, we cannot 100% remove ghc's dependency on `ghc-heap`, since when we compile `stage0:ghc`, `stage1:ghc-internal` is not yet available. Thus, when we compile with the boot-compiler, we still depend on an older version of `ghc-heap`, and only use the modules from `ghc-internal`, if the `ghc-internal` version is recent enough. ------------------------- Metric Increase: T24602_perf_size T25046_perf_size_gzip T25046_perf_size_unicode T25046_perf_size_unicode_gzip size_hello_artifact size_hello_artifact_gzip size_hello_unicode size_hello_unicode_gzip ------------------------- These metric increases are unfortunate, they are most likely caused by the larger (literally in terms of lines of code) stack decoder implementation that are now linked into hello-word binaries. On linux, it is almost a 10% increase, which is considerable. - - - - - bd80bb70 by fendor at 2025-08-30T05:10:08-04:00 Implement `decode` in terms of `decodeStackWithIpe` Uses the more efficient stack decoder implementation. - - - - - 24441165 by fendor at 2025-08-30T05:10:08-04:00 Remove stg_decodeStackzh - - - - - fb9cc882 by Simon Peyton Jones at 2025-08-30T05:10:51-04:00 Fix a long standing bug in the coercion optimiser We were mis-optimising ForAllCo, leading to #26345 Part of the poblem was the tricky tower of abstractions leading to the dreadful GHC.Core.TyCo.Subst.substForAllCoTyVarBndrUsing This function was serving two masters: regular substitution, but also coercion optimsation. So tricky was it that it did so wrong. In this MR I locate all the fancy footwork for coercion optimisation in GHC.Core.Coercion.Opt, where it belongs. That leaves substitution free to be much simpler. - - - - - 6c78de2d by Sylvain Henry at 2025-09-01T08:46:19-04:00 Driver: substitute virtual Prim module in --make mode too When we build ghc-internal with --make (e.g. with cabal-install), we need to be careful to substitute the virtual interface file for GHC.Internal.Prim: - after code generation (we generate code for an empty module, so we get an empty interface) - when we try to reload its .hi file - - - - - 26e0db16 by fendor at 2025-09-01T08:47:01-04:00 Expose Stack Annotation frames in IPE backtraces by default When decoding the Haskell-native call stack and displaying the IPE information for the stack frames, we print the `StackAnnotation` of the `AnnFrame` by default. This means, when an exception is thrown, any intermediate stack annotations will be displayed in the `IPE Backtrace`. Example backtrace: ``` Exception: ghc-internal:GHC.Internal.Exception.ErrorCall: Oh no! IPE backtrace: annotateCallStackIO, called at app/Main.hs:48:10 in backtrace-0.1.0.0-inplace-server:Main annotateCallStackIO, called at app/Main.hs:46:13 in backtrace-0.1.0.0-inplace-server:Main Main.handler (app/Main.hs:(46,1)-(49,30)) Main.liftIO (src/Servant/Server/Internal/Handler.hs:30:36-42) Servant.Server.Internal.Delayed.runHandler' (src/Servant/Server/Internal/Handler.hs:27:31-41) Control.Monad.Trans.Resource.runResourceT (./Control/Monad/Trans/Resource.hs:(192,14)-(197,18)) Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:195:20-22) Network.Wai.Handler.Warp.HTTP1.processRequest (./Network/Wai/Handler/Warp/HTTP1.hs:(195,5)-(203,31)) Network.Wai.Handler.Warp.HTTP1.http1server.loop (./Network/Wai/Handler/Warp/HTTP1.hs:(141,9)-(157,42)) HasCallStack backtrace: error, called at app/Main.hs:48:32 in backtrace-0.1.0.0-inplace-server:Main ``` The first two entries have been added by `annotateCallStackIO`, defined in `annotateCallStackIO`. - - - - - a1567efd by Sylvain Henry at 2025-09-01T23:01:35-04:00 RTS: rely less on Hadrian for flag setting (#25843) Hadrian used to pass -Dfoo command-line flags directly to build the rts. We can replace most of these flags with CPP based on cabal flags. It makes building boot libraries with cabal-install simpler (cf #25843). - - - - - ca5b0283 by Sergey Vinokurov at 2025-09-01T23:02:23-04:00 Remove unnecessary irrefutable patterns from Bifunctor instances for tuples Implementation of https://github.com/haskell/core-libraries-committee/issues/339 Metric Decrease: mhu-perf - - - - - 2da84b7a by sheaf at 2025-09-01T23:03:23-04:00 Only use active rules when simplifying rule RHSs When we are simplifying the RHS of a rule, we make sure to only apply rewrites from rules that are active throughout the original rule's range of active phases. For example, if a rule is always active, we only fire rules that are themselves always active when simplifying the RHS. Ditto for inline activations. This is achieved by setting the simplifier phase to a range of phases, using the new SimplPhaseRange constructor. Then: 1. When simplifying the RHS of a rule, or of a stable unfolding, we set the simplifier phase to a range of phases, computed from the activation of the RULE/unfolding activation, using the function 'phaseFromActivation'. The details are explained in Note [What is active in the RHS of a RULE?] in GHC.Core.Opt.Simplify.Utils. 2. The activation check for other rules and inlinings is then: does the activation of the other rule/inlining cover the whole phase range set in sm_phase? This continues to use the 'isActive' function, which now accounts for phase ranges. On the way, this commit also moves the exact-print SourceText annotation from the Activation datatype to the ActivationAnn type. This keeps the main Activation datatype free of any extra cruft. Fixes #26323 - - - - - 79816cc4 by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 cleanup: Move dehydrateCgBreakInfo to Stg2Bc This no longer has anything to do with Core. - - - - - 53da94ff by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 rts/Disassembler: Fix spacing of BRK_FUN - - - - - 08c0cf85 by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 debugger: Fix bciPtr in Step-out We need to use `BCO_NEXT` to move bciPtr to ix=1, because ix=0 points to the instruction itself! I do not understand how this didn't crash before. - - - - - e7e021fa by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 debugger: Allow BRK_FUNs to head case continuation BCOs When we start executing a BCO, we may want to yield to the scheduler: this may be triggered by a heap/stack check, context switch, or a breakpoint. To yield, we need to put the stack in a state such that when execution is resumed we are back to where we yielded from. Previously, a BKR_FUN could only head a function BCO because we only knew how to construct a valid stack for yielding from one -- simply add `apply_interp_info` + the BCO to resume executing. This is valid because the stack at the start of run_BCO is headed by that BCO's arguments. However, in case continuation BCOs (as per Note [Case continuation BCOs]), we couldn't easily reconstruct a valid stack that could be resumed because we dropped too soon the stack frames regarding the value returned (stg_ret) and received (stg_ctoi) by that continuation. This is especially tricky because of the variable type and size return frames (e.g. pointer ret_p/ctoi_R1p vs a tuple ret_t/ctoi_t2). The trick to being able to yield from a BRK_FUN at the start of a case cont BCO is to stop removing the ret frame headers eagerly and instead keep them until the BCO starts executing. The new layout at the start of a case cont. BCO is described by the new Note [Stack layout when entering run_BCO]. Now, we keep the ret_* and ctoi_* frames when entering run_BCO. A BRK_FUN is then executed if found, and the stack is yielded as-is with the preserved ret and ctoi frames. Then, a case cont BCO's instructions always SLIDE off the headers of the ret and ctoi frames, in StgToByteCode.doCase, turning a stack like | .... | +---------------+ | fv2 | +---------------+ | fv1 | +---------------+ | BCO | +---------------+ | stg_ctoi_ret_ | +---------------+ | retval | +---------------+ | stg_ret_..... | +---------------+ into | .... | +---------------+ | fv2 | +---------------+ | fv1 | +---------------+ | retval | +---------------+ for the remainder of the BCO. Moreover, this more uniform approach of keeping the ret and ctoi frames means we need less ad-hoc logic concerning the variable size of ret_tuple vs ret_p/np frames in the code generator and interpreter: Always keep the return to cont. stack intact at the start of run_BCO, and the statically generated instructions will take care of adjusting it. Unlocks BRK_FUNs at the start of case cont. BCOs which will enable a better user-facing step-out (#26042) which is free of the bugs the current BRK_ALTS implementation suffers from (namely, using BRK_FUN rather than BRK_ALTS in a case cont. means we'll never accidentally end up in a breakpoint "deeper" than the continuation, because we stop at the case cont itself rather than on the first breakpoint we evaluate after it). - - - - - ade3c1e6 by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 BRK_FUN with InternalBreakLocs for code-generation time breakpoints At the start of a case continuation BCO, place a BRK_FUN. This BRK_FUN uses the new "internal breakpoint location" -- allowing us to come up with a valid source location for this breakpoint that is not associated with a source-level tick. For case continuation BCOs, we use the last tick seen before it as the source location. The reasoning is described in Note [Debugger: Stepout internal break locs]. Note how T26042c, which was broken because it displayed the incorrect behavior of the previous step out when we'd end up at a deeper level than the one from which we initiated step-out, is now fixed. As of this commit, BRK_ALTS is now dead code and is thus dropped. Note [Debugger: Stepout internal break locs] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Step-out tells the interpreter to run until the current function returns to where it was called from, and stop there. This is achieved by enabling the BRK_FUN found on the first RET_BCO frame on the stack (See [Note Debugger: Step-out]). Case continuation BCOs (which select an alternative branch) must therefore be headed by a BRK_FUN. An example: f x = case g x of <--- end up here 1 -> ... 2 -> ... g y = ... <--- step out from here - `g` will return a value to the case continuation BCO in `f` - The case continuation BCO will receive the value returned from g - Match on it and push the alternative continuation for that branch - And then enter that alternative. If we step-out of `g`, the first RET_BCO on the stack is the case continuation of `f` -- execution should stop at its start, before selecting an alternative. (One might ask, "why not enable the breakpoint in the alternative instead?", because the alternative continuation is only pushed to the stack *after* it is selected by the case cont. BCO) However, the case cont. BCO is not associated with any source-level tick, it is merely the glue code which selects alternatives which do have source level ticks. Therefore, we have to come up at code generation time with a breakpoint location ('InternalBreakLoc') to display to the user when it is stopped there. Our solution is to use the last tick seen just before reaching the case continuation. This is robust because a case continuation will thus always have a relevant breakpoint location: - The source location will be the last source-relevant expression executed before the continuation is pushed - So the source location will point to the thing you've just stepped out of - Doing :step-local from there will put you on the selected alternative (which at the source level may also be the e.g. next line in a do-block) Examples, using angle brackets (<<...>>) to denote the breakpoint span: f x = case <<g x>> {- step in here -} of 1 -> ... 2 -> ...> g y = <<...>> <--- step out from here ... f x = <<case g x of <--- end up here, whole case highlighted 1 -> ... 2 -> ...>> doing :step-local ... f x = case g x of 1 -> <<...>> <--- stop in the alternative 2 -> ... A second example based on T26042d2, where the source is a do-block IO action, optimised to a chain of `case expressions`. main = do putStrLn "hello1" <<f>> <--- step-in here putStrLn "hello3" putStrLn "hello4" f = do <<putStrLn "hello2.1">> <--- step-out from here putStrLn "hello2.2" ... main = do putStrLn "hello1" <<f>> <--- end up here again, the previously executed expression putStrLn "hello3" putStrLn "hello4" doing step/step-local ... main = do putStrLn "hello1" f <<putStrLn "hello3">> <--- straight to the next line putStrLn "hello4" Finishes #26042 - - - - - c66910c0 by Rodrigo Mesquita at 2025-09-02T12:19:59-04:00 debugger: Re-use the last BreakpointId whole in step-out Previously, to come up with a location to stop at for `:stepout`, we would store the location of the last BreakpointId surrounding the continuation, as described by Note [Debugger: Stepout internal break locs]. However, re-using just the location from the last source breakpoint isn't sufficient to provide the necessary information in the break location. Specifically, it wouldn't bind any variables at that location. Really, there is no reason not to re-use the last breakpoint wholesale, and re-use all the information we had there. Step-out should behave just as if we had stopped at the call, but s.t. continuing will not re-execute the call. This commit updates the CgBreakInfo to always store a BreakpointId, be it the original one or the one we're emulating (for step-out). It makes variable bindings on :stepout work - - - - - e4abed7b by sheaf at 2025-09-02T12:20:40-04:00 Revert accidental changes to hie.yaml - - - - - 003b715b by meooow25 at 2025-09-02T23:48:51+02:00 Adjust the strictness of Data.List.iterate' * Don't force the next element in advance when generating a (:). * Force the first element to WHNF like every other element. Now every element in the output list is forced to WHNF when the (:) containing it is forced. CLC proposal: https://github.com/haskell/core-libraries-committee/issues/335 - - - - - b2f6aad0 by Simon Hengel at 2025-09-03T04:36:10-04:00 Refactoring: More consistently use logOutput, logInfo, fatalErrorMsg - - - - - 60a16db7 by Rodrigo Mesquita at 2025-09-03T10:55:50+01:00 bytecode: Don't PUSH_L 0; SLIDE 1 1 While looking through bytecode I noticed a quite common unfortunate pattern: ... PUSH_L 0 SLIDE 1 1 We do this often by generically constructing a tail call from a function atom that may be somewhere arbitrary on the stack. However, for the special case that the function can be found directly on top of the stack, as part of the arguments, it's plain redundant to push then slide it. In this commit we add a small optimisation to the generation of tailcalls in bytecode. Simply: lookahead for the function in the stack. If it is the first thing on the stack and it is part of the arguments which would be dropped as we entered the tail call, then don't push then slide it. In a simple example (T26042b), this already produced a drastic improvement in generated code (left is old, right is with this patch): ```diff 3c3 < 2025-07-29 10:14:02.081277 UTC ---

2025-07-29 10:50:36.560949 UTC 160,161c160 < PUSH_L 0 < SLIDE 1 2

SLIDE 1 1

164,165d162 < PUSH_L 0 < SLIDE 1 1 175,176c172 < PUSH_L 0 < SLIDE 1 2 ---

SLIDE 1 1

179,180d174 < PUSH_L 0 < SLIDE 1 1 206,207d199 < PUSH_L 0 < SLIDE 1 1 210,211d201 < PUSH_L 0 < SLIDE 1 1 214,215d203 < PUSH_L 0 < SLIDE 1 1 218,219d205 < PUSH_L 0 < SLIDE 1 1 222,223d207 < PUSH_L 0 < SLIDE 1 1 ... 600,601c566 < PUSH_L 0 < SLIDE 1 2 ---

SLIDE 1 1

604,605d568 < PUSH_L 0 < SLIDE 1 1 632,633d594 < PUSH_L 0 < SLIDE 1 1 636,637d596 < PUSH_L 0 < SLIDE 1 1 640,641d598 < PUSH_L 0 < SLIDE 1 1 644,645d600 < PUSH_L 0 < SLIDE 1 1 648,649d602 < PUSH_L 0 < SLIDE 1 1 652,653d604 < PUSH_L 0 < SLIDE 1 1 656,657d606 < PUSH_L 0 < SLIDE 1 1 660,661d608 < PUSH_L 0 < SLIDE 1 1 664,665d610 < PUSH_L 0 < SLIDE 1 1 ``` I also compiled lib:Cabal to bytecode and counted the number of bytecode lines with `find dist-newstyle -name "*.dump-BCOs" -exec wc {} +`: with unoptimized core: 1190689 lines (before) - 1172891 lines (now) = 17798 less redundant instructions (-1.5% lines) with optimized core: 1924818 lines (before) - 1864836 lines (now) = 59982 less redundant instructions (-3.1% lines) - - - - - 8b2c72c0 by L0neGamer at 2025-09-04T06:32:03-04:00 Add Control.Monad.thenM and Control.Applicative.thenA - - - - - 39e1b7cb by Teo Camarasu at 2025-09-04T06:32:46-04:00 ghc-internal: invert dependency of GHC.Internal.TH.Syntax on Data.Data This means that Data.Data no longer blocks building TH.Syntax, which allows greater parallelism in our builds. We move the Data.Data.Data instances to Data.Data. Quasi depends on Data.Data for one of its methods, so, we split the Quasi/Q, etc definition out of GHC.Internal.TH.Syntax into its own module. This has the added benefit of splitting up this quite large module. Previously TH.Syntax was a bottleneck when compiling ghc-internal. Now it is less of a bottle-neck and is also slightly quicker to compile (since it no longer contains these instances) at the cost of making Data.Data slightly more expensive to compile. TH.Lift which depends on TH.Syntax can also compile quicker and no longer blocks ghc-internal finishing to compile. Resolves #26217 ------------------------- Metric Decrease: MultiLayerModulesTH_OneShot T13253 T21839c T24471 Metric Increase: T12227 ------------------------- - - - - - bdf82fd2 by Teo Camarasu at 2025-09-04T06:32:46-04:00 compiler: delete unused names in Builtins.Names.TH returnQ and bindQ are no longer used in the compiler. There was also a very old comment that referred to them that I have modernized - - - - - 41a448e5 by Ben Gamari at 2025-09-04T19:21:43-04:00 hadrian: Pass lib & include directories to ghc `Setup configure` - - - - - 46bb9a79 by Ben Gamari at 2025-09-04T19:21:44-04:00 rts/IPE: Fix compilation when zstd is enabled This was broken by the refactoring undertaken in c80dd91c0bf6ac034f0c592f16c548b9408a8481. Closes #26312. - - - - - 138a6e34 by sheaf at 2025-09-04T19:22:46-04:00 Make mkCast assertion a bit clearer This commit changes the assertion message that gets printed when one calls mkCast with a coercion whose kind does not match the type of the inner expression. I always found the assertion message a bit confusing, as it didn't clearly state what exactly was the error. - - - - - 9d626be1 by sheaf at 2025-09-04T19:22:46-04:00 Simplifier/rules: fix mistakes in Notes & comments - - - - - 94b62aa7 by Simon Peyton Jones at 2025-09-08T03:37:14-04:00 Refactor ForAllCo This is a pure refactor, addressing #26389. It arranges that the kind coercion in a ForAllCo is a MCoercion, rather than a plain Coercion, thus removing redundancy in the common case. See (FC8) in Note [ForAllCo] It's a nice cleanup. - - - - - 624afa4a by sheaf at 2025-09-08T03:38:05-04:00 Use tcMkScaledFunTys in matchExpectedFunTys We should use tcMkScaledFunTys rather than mkScaledFunTys in GHC.Tc.Utils.Unify.matchExpectedFunTys, as the latter crashes when the kind of the result type is a bare metavariable. We know the result is always Type-like, so we don't need scaledFunTys to try to rediscover that from the kind. Fixes #26277 - - - - - 0975d2b6 by sheaf at 2025-09-08T03:38:54-04:00 Revert "Remove hptAllFamInstances usage during upsweep" This reverts commit 3bf6720eff5e86e673568e756161e6d6150eb440. - - - - - 0cf34176 by soulomoon at 2025-09-08T03:38:54-04:00 Family consistency checks: add test for #26154 This commit adds the test T26154, to make sure that GHC doesn't crash when performing type family consistency checks. This test case was extracted from Agda. Fixes #26154 - - - - - ba210d98 by Simon Peyton Jones at 2025-09-08T16:26:36+01:00 Report solid equality errors before custom errors This MR fixes #26255 by * Reporting solid equality errors like Int ~ Bool before "custom type errors". See comments in `report1` in `reportWanteds` * Suppressing errors that arise from superclasses of Wanteds. See (SCE1) in Note [Suppressing confusing errors] More details in #26255. - - - - - 261 changed files: - .gitlab-ci.yml - compiler/GHC/Builtin/Names/TH.hs - compiler/GHC/ByteCode/Asm.hs - compiler/GHC/ByteCode/Breakpoints.hs - compiler/GHC/ByteCode/Instr.hs - compiler/GHC/ByteCode/Types.hs - compiler/GHC/Core/Coercion.hs - compiler/GHC/Core/Coercion.hs-boot - compiler/GHC/Core/Coercion/Opt.hs - compiler/GHC/Core/Lint.hs - compiler/GHC/Core/Opt/Arity.hs - compiler/GHC/Core/Opt/Monad.hs - compiler/GHC/Core/Opt/Pipeline/Types.hs - compiler/GHC/Core/Opt/Simplify.hs - compiler/GHC/Core/Opt/Simplify/Env.hs - compiler/GHC/Core/Opt/Simplify/Inline.hs - compiler/GHC/Core/Opt/Simplify/Iteration.hs - compiler/GHC/Core/Opt/Simplify/Utils.hs - compiler/GHC/Core/Opt/SpecConstr.hs - compiler/GHC/Core/Opt/Specialise.hs - compiler/GHC/Core/Opt/WorkWrap.hs - compiler/GHC/Core/Reduction.hs - compiler/GHC/Core/Rules.hs - compiler/GHC/Core/TyCo/Compare.hs - compiler/GHC/Core/TyCo/FVs.hs - compiler/GHC/Core/TyCo/Rep.hs - compiler/GHC/Core/TyCo/Subst.hs - compiler/GHC/Core/TyCo/Tidy.hs - compiler/GHC/Core/Type.hs - compiler/GHC/Core/Unify.hs - compiler/GHC/Core/Utils.hs - compiler/GHC/CoreToIface.hs - compiler/GHC/Data/IOEnv.hs - compiler/GHC/Driver/CodeOutput.hs - compiler/GHC/Driver/Config/Core/Lint.hs - compiler/GHC/Driver/Config/Core/Opt/Simplify.hs - compiler/GHC/Driver/Downsweep.hs - compiler/GHC/Driver/Env.hs - compiler/GHC/Driver/Env/Types.hs - compiler/GHC/Driver/Main.hs - compiler/GHC/Driver/Make.hs - compiler/GHC/Driver/Pipeline.hs - compiler/GHC/Driver/Pipeline/Execute.hs - compiler/GHC/Hs/Binds.hs - compiler/GHC/Hs/Expr.hs - compiler/GHC/HsToCore/Pmc/Solver.hs - compiler/GHC/HsToCore/Quote.hs - compiler/GHC/HsToCore/Usage.hs - compiler/GHC/Iface/Load.hs - compiler/GHC/Iface/Make.hs - compiler/GHC/Iface/Recomp.hs - compiler/GHC/Iface/Recomp/Types.hs - compiler/GHC/Iface/Rename.hs - compiler/GHC/Iface/Syntax.hs - compiler/GHC/Iface/Type.hs - compiler/GHC/IfaceToCore.hs - compiler/GHC/Linker/Loader.hs - compiler/GHC/Parser.y - compiler/GHC/Plugins.hs - compiler/GHC/Rename/Splice.hs - compiler/GHC/Runtime/Debugger/Breakpoints.hs - compiler/GHC/Runtime/Eval.hs - compiler/GHC/Runtime/Heap/Inspect.hs - compiler/GHC/Stg/Lint.hs - compiler/GHC/StgToByteCode.hs - compiler/GHC/Tc/Deriv/Generics.hs - compiler/GHC/Tc/Errors.hs - compiler/GHC/Tc/Gen/App.hs - compiler/GHC/Tc/Gen/Bind.hs - compiler/GHC/Tc/Gen/Expr.hs - compiler/GHC/Tc/Gen/Expr.hs-boot - compiler/GHC/Tc/Gen/Head.hs - compiler/GHC/Tc/Gen/HsType.hs - compiler/GHC/Tc/Gen/Match.hs - compiler/GHC/Tc/Gen/Pat.hs - compiler/GHC/Tc/Gen/Splice.hs - compiler/GHC/Tc/Gen/Splice.hs-boot - compiler/GHC/Tc/Instance/Family.hs - compiler/GHC/Tc/Module.hs - compiler/GHC/Tc/TyCl/Utils.hs - compiler/GHC/Tc/Types.hs - compiler/GHC/Tc/Types/Constraint.hs - compiler/GHC/Tc/Types/Evidence.hs - compiler/GHC/Tc/Types/TH.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/ThToHs.hs - compiler/GHC/Types/Basic.hs - compiler/GHC/Types/Id/Make.hs - compiler/GHC/Unit/Finder.hs - compiler/GHC/Unit/Finder/Types.hs - compiler/GHC/Unit/Home/Graph.hs - compiler/GHC/Unit/Home/PackageTable.hs - compiler/GHC/Unit/Module/Deps.hs - compiler/GHC/Utils/Binary.hs - compiler/ghc.cabal.in - configure.ac - docs/users_guide/9.16.1-notes.rst - docs/users_guide/separate_compilation.rst - ghc/GHCi/UI.hs - hadrian/src/Rules/ToolArgs.hs - hadrian/src/Settings/Default.hs - hadrian/src/Settings/Packages.hs - libraries/base/changelog.md - libraries/base/src/Control/Applicative.hs - libraries/base/src/Control/Monad.hs - libraries/base/src/Data/Array/Byte.hs - libraries/base/src/Data/Bifunctor.hs - libraries/base/src/Data/Fixed.hs - libraries/base/src/GHC/Stack/CloneStack.hs - + libraries/ghc-boot-th/GHC/Boot/TH/Monad.hs - libraries/ghc-boot-th/GHC/Boot/TH/Ppr.hs - libraries/ghc-boot-th/ghc-boot-th.cabal.in - libraries/ghc-experimental/src/GHC/Stack/Annotation/Experimental.hs - libraries/ghc-heap/GHC/Exts/Heap/ClosureTypes.hs - libraries/ghc-heap/GHC/Exts/Heap/Closures.hs - + libraries/ghc-heap/GHC/Exts/Heap/Constants.hs - + libraries/ghc-heap/GHC/Exts/Heap/InfoTable.hs - + libraries/ghc-heap/GHC/Exts/Heap/InfoTable/Types.hs - + libraries/ghc-heap/GHC/Exts/Heap/InfoTableProf.hs - libraries/ghc-heap/GHC/Exts/Heap/ProfInfo/Types.hs - + libraries/ghc-heap/GHC/Exts/Stack/Constants.hs - libraries/ghc-heap/GHC/Exts/Stack/Decode.hs - libraries/ghc-heap/ghc-heap.cabal.in - − libraries/ghc-heap/tests/stack-annotation/ann_frame004.stdout - libraries/ghc-heap/cbits/HeapPrim.cmm → libraries/ghc-internal/cbits/HeapPrim.cmm - libraries/ghc-heap/cbits/Stack.cmm → libraries/ghc-internal/cbits/Stack.cmm - libraries/ghc-internal/cbits/StackCloningDecoding.cmm - libraries/ghc-heap/cbits/Stack_c.c → libraries/ghc-internal/cbits/Stack_c.c - libraries/ghc-internal/ghc-internal.cabal.in - libraries/ghc-internal/jsbits/base.js - libraries/ghc-internal/src/GHC/Internal/Base.hs - libraries/ghc-internal/src/GHC/Internal/Control/Monad.hs - libraries/ghc-internal/src/GHC/Internal/Data/Data.hs - libraries/ghc-internal/src/GHC/Internal/Exception/Backtrace.hs - + libraries/ghc-internal/src/GHC/Internal/Heap/Closures.hs - libraries/ghc-heap/GHC/Exts/Heap/Constants.hsc → libraries/ghc-internal/src/GHC/Internal/Heap/Constants.hsc - libraries/ghc-heap/GHC/Exts/Heap/InfoTable.hsc → libraries/ghc-internal/src/GHC/Internal/Heap/InfoTable.hsc - libraries/ghc-heap/GHC/Exts/Heap/InfoTable/Types.hsc → libraries/ghc-internal/src/GHC/Internal/Heap/InfoTable/Types.hsc - libraries/ghc-heap/GHC/Exts/Heap/InfoTableProf.hsc → libraries/ghc-internal/src/GHC/Internal/Heap/InfoTableProf.hsc - + libraries/ghc-internal/src/GHC/Internal/Heap/ProfInfo/Types.hs - libraries/ghc-internal/src/GHC/Internal/List.hs - + libraries/ghc-internal/src/GHC/Internal/Stack/Annotation.hs - libraries/ghc-internal/src/GHC/Internal/Stack/CloneStack.hs - libraries/ghc-heap/GHC/Exts/Stack/Constants.hsc → libraries/ghc-internal/src/GHC/Internal/Stack/Constants.hsc - + libraries/ghc-internal/src/GHC/Internal/Stack/Decode.hs - libraries/ghc-internal/src/GHC/Internal/System/Posix/Internals.hs - libraries/ghc-internal/src/GHC/Internal/TH/Lib.hs - libraries/ghc-internal/src/GHC/Internal/TH/Lift.hs - + libraries/ghc-internal/src/GHC/Internal/TH/Monad.hs - libraries/ghc-internal/src/GHC/Internal/TH/Quote.hs - libraries/ghc-internal/src/GHC/Internal/TH/Syntax.hs - libraries/ghc-heap/tests/stack-annotation/Makefile → libraries/ghc-internal/tests/stack-annotation/Makefile - libraries/ghc-heap/tests/stack-annotation/TestUtils.hs → libraries/ghc-internal/tests/stack-annotation/TestUtils.hs - libraries/ghc-heap/tests/stack-annotation/all.T → libraries/ghc-internal/tests/stack-annotation/all.T - libraries/ghc-heap/tests/stack-annotation/ann_frame001.hs → libraries/ghc-internal/tests/stack-annotation/ann_frame001.hs - libraries/ghc-heap/tests/stack-annotation/ann_frame001.stdout → libraries/ghc-internal/tests/stack-annotation/ann_frame001.stdout - libraries/ghc-heap/tests/stack-annotation/ann_frame002.hs → libraries/ghc-internal/tests/stack-annotation/ann_frame002.hs - libraries/ghc-heap/tests/stack-annotation/ann_frame002.stdout → libraries/ghc-internal/tests/stack-annotation/ann_frame002.stdout - libraries/ghc-heap/tests/stack-annotation/ann_frame003.hs → libraries/ghc-internal/tests/stack-annotation/ann_frame003.hs - libraries/ghc-heap/tests/stack-annotation/ann_frame003.stdout → libraries/ghc-internal/tests/stack-annotation/ann_frame003.stdout - libraries/ghc-heap/tests/stack-annotation/ann_frame004.hs → libraries/ghc-internal/tests/stack-annotation/ann_frame004.hs - + libraries/ghc-internal/tests/stack-annotation/ann_frame004.stdout - libraries/ghci/GHCi/Message.hs - libraries/ghci/GHCi/Run.hs - libraries/ghci/GHCi/TH.hs - libraries/ghci/ghci.cabal.in - libraries/template-haskell/Language/Haskell/TH/Lib.hs - libraries/template-haskell/Language/Haskell/TH/Quote.hs - libraries/template-haskell/Language/Haskell/TH/Syntax.hs - libraries/template-haskell/changelog.md - rts/CloneStack.c - rts/CloneStack.h - rts/Disassembler.c - rts/IPE.c - rts/Interpreter.c - rts/Profiling.c - rts/RtsMessages.c - rts/RtsSymbols.c - rts/RtsUtils.c - rts/Trace.c - rts/include/rts/Bytecodes.h - testsuite/.gitignore - testsuite/tests/count-deps/CountDepsAst.stdout - testsuite/tests/count-deps/CountDepsParser.stdout - testsuite/tests/deriving/should_compile/T14682.stderr - testsuite/tests/deriving/should_compile/drv-empty-data.stderr - + testsuite/tests/driver/make-prim/GHC/Internal/Prim.hs - + testsuite/tests/driver/make-prim/Makefile - + testsuite/tests/driver/make-prim/Test.hs - + testsuite/tests/driver/make-prim/Test2.hs - + testsuite/tests/driver/make-prim/all.T - testsuite/tests/ghci.debugger/scripts/T26042b.script - testsuite/tests/ghci.debugger/scripts/T26042b.stdout - testsuite/tests/ghci.debugger/scripts/T26042c.script - testsuite/tests/ghci.debugger/scripts/T26042c.stdout - + testsuite/tests/ghci.debugger/scripts/T26042d2.hs - + testsuite/tests/ghci.debugger/scripts/T26042d2.script - + testsuite/tests/ghci.debugger/scripts/T26042d2.stdout - testsuite/tests/ghci.debugger/scripts/T26042e.stdout - 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utils/check-exact/ExactPrint.hs The diff was not included because it is too large. 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