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* Refactor the treatment of loopy superclass dictswip/T20666Richard Eisenberg2023-01-111-10/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch completely re-engineers how we deal with loopy superclass dictionaries in instance declarations. It fixes #20666 and #19690 The highlights are * Recognise that the loopy-superclass business should use precisely the Paterson conditions. This is much much nicer. See Note [Recursive superclasses] in GHC.Tc.TyCl.Instance * With that in mind, define "Paterson-smaller" in Note [Paterson conditions] in GHC.Tc.Validity, and the new data type `PatersonSize` in GHC.Tc.Utils.TcType, along with functions to compute and compare PatsonSizes * Use the new PatersonSize stuff when solving superclass constraints See Note [Solving superclass constraints] in GHC.Tc.TyCl.Instance * In GHC.Tc.Solver.Monad.lookupInInerts, add a missing call to prohibitedSuperClassSolve. This was the original cause of #20666. * Treat (TypeError "stuff") as having PatersonSize zero. See Note [Paterson size for type family applications] in GHC.Tc.Utils.TcType. * Treat the head of a Wanted quantified constraint in the same way as the superclass of an instance decl; this is what fixes #19690. See GHC.Tc.Solver.Canonical Note [Solving a Wanted forall-constraint] (Thanks to Matthew Craven for this insight.) This entailed refactoring the GivenSc constructor of CtOrigin a bit, to say whether it comes from an instance decl or quantified constraint. * Some refactoring way in which redundant constraints are reported; we don't want to complain about the extra, apparently-redundant constraints that we must add to an instance decl because of the loopy-superclass thing. I moved some work from GHC.Tc.Errors to GHC.Tc.Solver. * Add a new section to the user manual to describe the loopy superclass issue and what rules it follows.
* Introduce the TypeAbstractions language flagVladislav Zavialov2023-01-114-80/+99
| | | | | | | | | | | | | | | | | | | | | | | | | GHC Proposals #448 "Modern scoped type variables" and #425 "Invisible binders in type declarations" introduce a new language extension flag: TypeAbstractions. Part of the functionality guarded by this flag has already been implemented, namely type abstractions in constructor patterns, but it was guarded by a combination of TypeApplications and ScopedTypeVariables instead of a dedicated language extension flag. This patch does the following: * introduces a new language extension flag TypeAbstractions * requires TypeAbstractions for @a-syntax in constructor patterns instead of TypeApplications and ScopedTypeVariables * creates a User's Guide page for TypeAbstractions and moves the "Type Applications in Patterns" section there To avoid a breaking change, the new flag is implied by ScopedTypeVariables and is retroactively added to GHC2021. Metric Decrease: MultiLayerModulesTH_OneShot
* Added a new warning about compatibility with RequiredTypeArgumentsHaskellMouse2023-01-112-0/+26
| | | | | | | | | This commit introduces a new warning that indicates code incompatible with future extension: RequiredTypeArguments. Enabling this extension may break some code and the warning will help to make it compatible in advance.
* Misc cleanupKrzysztof Gogolewski2023-01-052-2/+5
| | | | | | | | | - Remove unused uniques and hs-boot declarations - Fix types of seq and unsafeCoerce# - Remove FastString/String roundtrip in JS - Use TTG to enforce totality - Remove enumeration in Heap/Inspect; the 'otherwise' clause serves the primitive types well.
* sphinx: Use modern syntax for extlinksMatthew Pickering2023-01-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | This fixes the following build error: ``` Command line: /opt/homebrew/opt/sphinx-doc/bin/sphinx-build -b man -d /private/tmp/extra-dir-55768274273/.doctrees-man -n -w /private/tmp/extra-dir-55768274273/.log docs/users_guide /private/tmp/extra-dir-55768274273 ===> Command failed with error code: 2 Exception occurred: File "/opt/homebrew/Cellar/sphinx-doc/6.0.0/libexec/lib/python3.11/site-packages/sphinx/ext/extlinks.py", line 101, in role title = caption % part ~~~~~~~~^~~~~~ TypeError: not all arguments converted during string formatting ``` I tested on Sphinx-5.1.1 and Sphinx-6.0.0 Thanks for sterni for providing instructions about how to test using sphinx-6.0.0. Fixes #22690
* compiler: Add -f[no-]split-sections flagsMatthew Pickering2023-01-041-1/+3
| | | | | | | | Here we add a `-fsplit-sections` flag which may some day replace `-split-sections`. This has the advantage of automatically providing a `-fno-split-sections` flag, which is useful for our packaging because we enable `-split-sections` by default but want to disable it in certain configurations.
* Drop support for kind constraints.wip/p547Richard Eisenberg2022-12-241-34/+2
| | | | | | | | | | | | | | | | | | | | | | | | This implements proposal 547 and closes ticket #22298. See the proposal and ticket for motivation. Compiler perf improves a bit Metrics: compile_time/bytes allocated ------------------------------------- CoOpt_Singletons(normal) -2.4% GOOD T12545(normal) +1.0% T13035(normal) -13.5% GOOD T18478(normal) +0.9% T9872d(normal) -2.2% GOOD geo. mean -0.2% minimum -13.5% maximum +1.0% Metric Decrease: CoOpt_Singletons T13035 T9872d
* codeGen: Introduce ThreadSanitizer instrumentationBen Gamari2022-12-151-0/+16
| | | | | | This introduces a new Cmm pass which instruments the program with ThreadSanitizer annotations, allowing full tracking of mutator memory accesses via TSAN.
* Fix #22300 Document GHC's extensions to valid whitespaceMike Pilgrem2022-12-092-0/+30
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* Document TH splices' interaction with INCOHERENT instancesRyan Scott2022-12-091-0/+72
| | | | | | | | | Top-level declaration splices can having surprising interactions with `INCOHERENT` instances, as observed in #22492. This patch resolves #22492 by documenting this strange interaction in the GHC User's Guide. [ci skip]
* Properly cast values when writing/reading unboxed sums.Andreas Klebinger2022-11-301-0/+10
| | | | | | | Unboxed sums might store a Int8# value as Int64#. This patch makes sure we keep track of the actual value type. See Note [Casting slot arguments] for the details.
* Add Javascript backendSylvain Henry2022-11-291-0/+6
| | | | | | | | | | | | | | | Add JS backend adapted from the GHCJS project by Luite Stegeman. Some features haven't been ported or implemented yet. Tests for these features have been disabled with an associated gitlab ticket. Bump array submodule Work funded by IOG. Co-authored-by: Jeffrey Young <jeffrey.young@iohk.io> Co-authored-by: Luite Stegeman <stegeman@gmail.com> Co-authored-by: Josh Meredith <joshmeredith2008@gmail.com>
* Print unticked promoted data constructors (#20531)Vladislav Zavialov2022-11-251-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch, GHC unconditionally printed ticks before promoted data constructors: ghci> type T = True -- unticked (user-written) ghci> :kind! T T :: Bool = 'True -- ticked (compiler output) After this patch, GHC prints ticks only when necessary: ghci> type F = False -- unticked (user-written) ghci> :kind! F F :: Bool = False -- unticked (compiler output) ghci> data False -- introduce ambiguity ghci> :kind! F F :: Bool = 'False -- ticked by necessity (compiler output) The old behavior can be enabled by -fprint-redundant-promotion-ticks. Summary of changes: * Rename PrintUnqualified to NamePprCtx * Add QueryPromotionTick to it * Consult the GlobalRdrEnv to decide whether to print a tick (see mkPromTick) * Introduce -fprint-redundant-promotion-ticks Co-authored-by: Artyom Kuznetsov <hi@wzrd.ht>
* CApiFFI: add ConstPtr for encoding const-qualified pointer return types (#22043)nineonine2022-11-232-0/+15
| | | | | | | | | | | | | Previously, when using `capi` calling convention in foreign declarations, code generator failed to handle const-cualified pointer return types. This resulted in CC toolchain throwing `-Wincompatible-pointer-types-discards-qualifiers` warning. `Foreign.C.Types.ConstPtr` newtype was introduced to handle these cases - special treatment was put in place to generate appropritetly qualified C wrapper that no longer triggers the above mentioned warning. Fixes #22043
* Add documentation on custom Prelude modules (#22228)Lawton Nichols2022-11-231-3/+42
| | | | Specifically, custom Prelude modules that are named `Prelude`.
* Misc cleanupKrzysztof Gogolewski2022-11-162-2/+1
| | | | | | | * Replace catMaybes . map f with mapMaybe f * Use concatFS to concatenate multiple FastStrings * Fix documentation of -exclude-module * Cleanup getIgnoreCount in GHCi.UI
* Implement UNPACK support for sum types.Madeline Haraj2022-11-141-1/+7
| | | | | | | This is based on osa's unpack_sums PR from ages past. The meat of the patch is implemented in dataConArgUnpackSum and described in Note [UNPACK for sum types].
* Typo: rename -fwrite-if-simplfied-core to -fwrite-if-simplified-coreKrzysztof Gogolewski2022-11-011-4/+4
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* Fix syntaxKrzysztof Gogolewski2022-10-211-1/+1
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* Document how to quote certain names with spacesDavid Feuer2022-10-211-7/+8
| | | | | | | Quoting a name for Template Haskell is a bit tricky if the second character of that name is a single quote. The User's Guide falsely claimed that it was impossible. Document how to do it. Fixes #22236
* runhaskellEric Lindblad2022-10-211-1/+1
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* Small language fixes in 'Using GHC'Jan Hrček2022-10-191-6/+6
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* Add -fsuppress-error-contexts to disable printing error contexts in errorswip/diagnostics-configMatthew Pickering2022-10-181-0/+12
| | | | | | | | | | | | | In many development environments, the source span is the primary means of seeing what an error message relates to, and the In the expression: and In an equation for: clauses are not particularly relevant. However, they can grow to be quite long, which can make the message itself both feel overwhelming and interact badly with limited-space areas. It's simple to implement this flag so we might as well do it and give the user control about how they see their messages. Fixes #21722
* Add realease note for #21927Teo Camarasu2022-10-151-0/+6
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* Add standard Unicode case predicates isUpperCase and isLowerCase.Pierre Le Marre2022-10-141-0/+5
| | | | | | | | These predicates use the standard Unicode case properties and are more intuitive than isUpper and isLower. Approved by CLC in https://github.com/haskell/core-libraries-committee/issues/90#issuecomment-1276649403. Fixes #14589
* Update phases.rst Simon Hengel2022-10-131-2/+2
| | | (the name of the original source file is $1, not $2)
* Unrestricted OverloadedLabels (#11671)Charles Taylor2022-10-121-0/+9
| | | | | Implements GHC proposal: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0170-unrestricted-overloadedlabels.rst
* Teach -fno-code about -fprefer-byte-codeMatthew Pickering2022-10-111-0/+5
| | | | | | | | | | | | | | | | | This patch teachs the code generation logic of -fno-code about -fprefer-byte-code, so that if we need to generate code for a module which prefers byte code, then we generate byte code rather than object code. We keep track separately which modules need object code and which byte code and then enable the relevant code generation for each. Typically the option will be enabled globally so one of these sets should be empty and we will just turn on byte code or object code generation. We also fix the bug where we would generate code for a module which enables Template Haskell despite the fact it was unecessary. Fixes #22016
* Interface Files with Core DefinitionsMatthew Pickering2022-10-111-1/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds three new flags * -fwrite-if-simplified-core: Writes the whole core program into an interface file * -fbyte-code-and-object-code: Generate both byte code and object code when compiling a file * -fprefer-byte-code: Prefer to use byte-code if it's available when running TH splices. The goal for including the core bindings in an interface file is to be able to restart the compiler pipeline at the point just after simplification and before code generation. Once compilation is restarted then code can be created for the byte code backend. This can significantly speed up start-times for projects in GHCi. HLS already implements its own version of these extended interface files for this reason. Preferring to use byte-code means that we can avoid some potentially expensive code generation steps (see #21700) * Producing object code is much slower than producing bytecode, and normally you need to compile with `-dynamic-too` to produce code in the static and dynamic way, the dynamic way just for Template Haskell execution when using a dynamically linked compiler. * Linking many large object files, which happens once per splice, can be quite expensive compared to linking bytecode. And you can get GHC to compile the necessary byte code so `-fprefer-byte-code` has access to it by using `-fbyte-code-and-object-code`. Fixes #21067
* Minor fixes following Unicode 15.0.0 updatePierre Le Marre2022-10-051-0/+2
| | | | | - Fix changelog for Unicode 15.0.0 - Fix the checksums of the downloaded Unicode files, in base's tool: "ucd2haskell".
* Fix docs for pattern synonymsBrandon Chinn2022-10-041-2/+2
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* Demand: Format Call SubDemands `Cn(sd)` as `C(n,sd)` (#22231)wip/T22231Sebastian Graf2022-09-291-4/+4
| | | | | | | | Justification in #22231. Short form: In a demand like `1C1(C1(L))` it was too easy to confuse which `1` belongs to which `C`. Now that should be more obvious. Fixes #22231
* matchLocalInst: do domination analysissheaf2022-09-281-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | When multiple Given quantified constraints match a Wanted, and there is a quantified constraint that dominates all others, we now pick it to solve the Wanted. See Note [Use only the best matching quantified constraint]. For example: [G] d1: forall a b. ( Eq a, Num b, C a b ) => D a b [G] d2: forall a . C a Int => D a Int [W] {w}: D a Int When solving the Wanted, we find that both Givens match, but we pick the second, because it has a weaker precondition, C a Int, compared to (Eq a, Num Int, C a Int). We thus say that d2 dominates d1; see Note [When does a quantified instance dominate another?]. This domination test is done purely in terms of superclass expansion, in the function GHC.Tc.Solver.Interact.impliedBySCs. We don't attempt to do a full round of constraint solving; this simple check suffices for now. Fixes #22216 and #22223
* implement proposal 106 (Define Kinds Without Promotion) (fixes #6024)Ross Paterson2022-09-274-0/+68
| | | | includes corresponding changes to haddock submodule
* users-guide: fix incorrect ghcappdata folder for unix and windowsMon Aaraj2022-09-211-6/+5
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* docs: clarify that LLVM codegen is not available in unregisterised modematoro2022-09-201-4/+3
| | | | | | | | | | | | | The current docs are misleading and suggest that it is possible to use LLVM codegen from an unregisterised build. This is not the case; attempting to pass `-fllvm` to an unregisterised build warns: ``` when making flags consistent: warning: Target platform uses unregisterised ABI, so compiling via C ``` and uses the C codegen anyway.
* Fix -Woperator-whitespace for consym (part of #19372)Vladislav Zavialov2022-09-201-0/+3
| | | | | | | | | | | | | | Due to an oversight, the initial specification and implementation of -Woperator-whitespace focused on varsym exclusively and completely ignored consym. This meant that expressions such as "x+ y" would produce a warning, while "x:+ y" would not. The specification was corrected in ghc-proposals pull request #404, and this patch updates the implementation accordingly. Regression test included.
* Document :unadd GHCi command in user guideJan Hrček2022-09-201-10/+22
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* Add links to the continuations haddocks in the docs for each primopAlexis King2022-09-161-1/+1
| | | | fixes #22176
* Fix typosKrzysztof Gogolewski2022-09-147-9/+9
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* Allow imports to reference multiple fields with the same name (#21625)Adam Gundry2022-09-131-1/+8
| | | | | | | | | | | | | | If a module `M` exports two fields `f` (using DuplicateRecordFields), we can still accept import M (f) import M hiding (f) and treat `f` as referencing both of them. This was accepted in GHC 9.0, but gave rise to an ambiguity error in GHC 9.2. See #21625. This patch also documents this behaviour in the user's guide, and updates the test for #16745 which is now treated differently.
* Add diagnostic codessheaf2022-09-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This MR adds diagnostic codes, assigning unique numeric codes to error and warnings, e.g. error: [GHC-53633] Pattern match is redundant This is achieved as follows: - a type family GhcDiagnosticCode that gives the diagnostic code for each diagnostic constructor, - a type family ConRecursInto that specifies whether to recur into an argument of the constructor to obtain a more fine-grained code (e.g. different error codes for different 'deriving' errors), - generics machinery to generate the value-level function assigning each diagnostic its error code; see Note [Diagnostic codes using generics] in GHC.Types.Error.Codes. The upshot is that, to add a new diagnostic code, contributors only need to modify the two type families mentioned above. All logic relating to diagnostic codes is thus contained to the GHC.Types.Error.Codes module, with no code duplication. This MR also refactors error message datatypes a bit, ensuring we can derive Generic for them, and cleans up the logic around constraint solver reports by splitting up 'TcSolverReportInfo' into separate datatypes (see #20772). Fixes #21684
* Add native delimited continuations to the RTSAlexis King2022-09-111-4/+13
| | | | | | | | | | | | | | | | | | | | | This patch implements GHC proposal 313, "Delimited continuation primops", by adding native support for delimited continuations to the GHC RTS. All things considered, the patch is relatively small. It almost exclusively consists of changes to the RTS; the compiler itself is essentially unaffected. The primops come with fairly extensive Haddock documentation, and an overview of the implementation strategy is given in the Notes in rts/Continuation.c. This first stab at the implementation prioritizes simplicity over performance. Most notably, every continuation is always stored as a single, contiguous chunk of stack. If one of these chunks is particularly large, it can result in poor performance, as the current implementation does not attempt to cleverly squeeze a subset of the stack frames into the existing stack: it must fit all at once. If this proves to be a performance issue in practice, a cleverer strategy would be a worthwhile target for future improvements.
* Fix :add docs in user guideJan Hrček2022-09-061-1/+1
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* Update instances.rst, clarifying InstanceSigssheaf2022-09-061-5/+30
| | | | Fixes #22103
* Change Ord defaults per CLC proposalTommy Bidne2022-09-011-0/+4
| | | | Approved by CLC in https://github.com/haskell/core-libraries-committee/issues/24#issuecomment-1233331267
* users-guide: Document system-cxx-std-libBen Gamari2022-08-311-0/+20
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* Drop make build systemBen Gamari2022-08-251-50/+0
| | | | | | | | | | | Here we at long last remove the `make`-based build system, it having been replaced with the Shake-based Hadrian build system. Users are encouraged to refer to the documentation in `hadrian/doc` and this [1] blog post for details on using Hadrian. Closes #17527. [1] https://www.haskell.org/ghc/blog/20220805-make-to-hadrian.html
* Recognize file-header pragmas in GHCi (#21507)MorrowM2022-08-212-0/+24
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* 19217 Implicitly quantify type variables in :kind commandSasha Bogicevic2022-08-191-0/+8
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