summaryrefslogtreecommitdiff
path: root/docs
Commit message (Collapse)AuthorAgeFilesLines
* Track type variable scope more carefully.Richard Eisenberg2018-03-311-1/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main job of this commit is to track more accurately the scope of tyvars introduced by user-written foralls. For example, it would be to have something like this: forall a. Int -> (forall k (b :: k). Proxy '[a, b]) -> Bool In that type, a's kind must be k, but k isn't in scope. We had a terrible way of doing this before (not worth repeating or describing here, but see the old tcImplicitTKBndrs and friends), but now we have a principled approach: make an Implication when kind-checking a forall. Doing so then hooks into the existing machinery for preventing skolem-escape, performing floating, etc. This also means that we bump the TcLevel whenever going into a forall. The new behavior is done in TcHsType.scopeTyVars, but see also TcHsType.tc{Im,Ex}plicitTKBndrs, which have undergone significant rewriting. There are several Notes near there to guide you. Of particular interest there is that Implication constraints can now have skolems that are out of order; this situation is reported in TcErrors. A major consequence of this is a slightly tweaked process for type- checking type declarations. The new Note [Use SigTvs in kind-checking pass] in TcTyClsDecls lays it out. The error message for dependent/should_fail/TypeSkolEscape has become noticeably worse. However, this is because the code in TcErrors goes to some length to preserve pre-8.0 error messages for kind errors. It's time to rip off that plaster and get rid of much of the kind-error-specific error messages. I tried this, and doing so led to a lovely error message for TypeSkolEscape. So: I'm accepting the error message quality regression for now, but will open up a new ticket to fix it, along with a larger error-message improvement I've been pondering. This applies also to dependent/should_fail/{BadTelescope2,T14066,T14066e}, polykinds/T11142. Other minor changes: - isUnliftedTypeKind didn't look for tuples and sums. It does now. - check_type used check_arg_type on both sides of an AppTy. But the left side of an AppTy isn't an arg, and this was causing a bad error message. I've changed it to use check_type on the left-hand side. - Some refactoring around when we print (TYPE blah) in error messages. The changes decrease the times when we do so, to good effect. Of course, this is still all controlled by -fprint-explicit-runtime-reps Fixes #14066 #14749 Test cases: dependent/should_compile/{T14066a,T14749}, dependent/should_fail/T14066{,c,d,e,f,g,h}
* Remove MAX_PATH restrictions from RTS, I/O manager and various utilitiesTamar Christina2018-03-311-2/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This shims out fopen and sopen so that they use modern APIs under the hood along with namespaced paths. This lifts the MAX_PATH restrictions from Haskell programs and makes the new limit ~32k. There are only some slight caveats that have been documented. Some utilities have not been upgraded such as lndir, since all these things are different cabal packages I have been forced to copy the source in different places which is less than ideal. But it's the only way to keep sdist working. Test Plan: ./validate Reviewers: hvr, bgamari, erikd, simonmar Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #10822 Differential Revision: https://phabricator.haskell.org/D4416
* Fix syntax in -flate-specialise docsSimon Jakobi2018-03-291-0/+2
|
* Add new debugging flag -dinline-checkBen Gamari2018-03-251-0/+14
| | | | | | | | | | | | | | | | | | | | | | | This flag reports a summary of the inlining decision for identifiers prefixed by the flag's argument. For example, `-dinline-check foo` will report why definitions whose prefix is `foo` are inlined or not. Previously the only way to get this information was to pass a combination of `-dverbose-core2core` and `-ddump-inlinings`. This combination led to a log of 12 million lines in a module of about 200 lines I recently had to apply it to. This flag provides a much more direct way to find the occurence you care about. Reviewers: osa1, dfeuer, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4458
* Fix scoped type variables in TH for several constructsHE, Tao2018-03-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | Namely class methods, default signatures and pattern synonyms. When scoped type variables occur inside class default methods, default signatures and pattern synonyms, avoid re-create explicit type variables when represent the type signatures. This patch should fix Trac#14885. Signed-off-by: HE, Tao <sighingnow@gmail.com> Test Plan: make test TEST="T14885a T14885b T14885c" Reviewers: goldfire, bgamari, simonpj, RyanGlScott Reviewed By: simonpj, RyanGlScott Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14885 Differential Revision: https://phabricator.haskell.org/D4469
* document: fix trac issue #14229Võ Anh Duy2018-03-251-2/+2
| | | | | | | | | | | | | | | Accroding to https://git.haskell.org/ghc.git/commitdiff/49672659113371c3bee691e6d913d f8e6f60a1d8, `-Wredundant-constraints` is no longer turn on by default. Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4528
* Allow PartialTypeSignatures in standalone deriving contextsRyan Scott2018-03-232-2/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: At its core, this patch is a simple tweak that allows a user to write: ```lang=haskell deriving instance _ => Eq (Foo a) ``` Which is functionally equivalent to: ```lang=haskell data Foo a = ... deriving Eq ``` But with the added flexibility that `StandaloneDeriving` gives you (namely, the ability to use it anywhere, not just in the same module that `Foo` was declared in). This fixes #13324, and should hopefully address a use case brought up in #10607. Currently, only the use of a single, extra-constraints wildcard is permitted in a standalone deriving declaration. Any other wildcard is rejected, so things like `deriving instance (Eq a, _) => Eq (Foo a)` are currently forbidden. There are quite a few knock-on changes brought on by this change: * The `HsSyn` type used to represent standalone-derived instances was previously `LHsSigType`, which isn't sufficient to hold wildcard types. This needed to be changed to `LHsSigWcType` as a result. * Previously, `DerivContext` was a simple type synonym for `Maybe ThetaType`, under the assumption that you'd only ever be in the `Nothing` case if you were in a `deriving` clause. After this patch, that assumption no longer holds true, as you can also be in this situation with standalone deriving when an extra-constraints wildcard is used. As a result, I changed `DerivContext` to be a proper datatype that reflects the new wrinkle that this patch adds, and plumbed this through the relevant parts of `TcDeriv` and friends. * Relatedly, the error-reporting machinery in `TcErrors` also assumed that if you have any unsolved constraints in a derived instance, then you should be able to fix it by switching over to standalone deriving. This was always sound advice before, but with this new feature, it's possible to have unsolved constraints even when you're standalone-deriving something! To rectify this, I tweaked some constructors of `CtOrigin` a bit to reflect this new subtlety. This requires updating the Haddock submodule. See my fork at https://github.com/RyanGlScott/haddock/commit/067d52fd4be15a1842cbb05f42d9d482de0ad3a7 Test Plan: ./validate Reviewers: simonpj, goldfire, bgamari Reviewed By: simonpj Subscribers: goldfire, rwbarton, thomie, mpickering, carter GHC Trac Issues: #13324 Differential Revision: https://phabricator.haskell.org/D4383
* Special-case record fields ending with hash when deriving ReadRyan Scott2018-03-232-2/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: In commit dbd81f7e86514498218572b9d978373b1699cc5b, a regression was inadvertently introduced which caused derived `Read` instances for record data types with fields ending in a `#` symbol (using `MagicHash`) would no longer parse on valid output. This is ultimately due to the same reasons as #5041, as we cannot parse a field name like `foo#` as a single identifier. We fix this issue by employing the same workaround as in #5041: first parse the identifier name `foo`, then then symbol `#`. This is accomplished by the new `readFieldHash` function in `GHC.Read`. This will likely warrant a `base-4.11.1.0` release. Test Plan: make test TEST=T14918 Reviewers: tdammers, hvr, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14918 Differential Revision: https://phabricator.haskell.org/D4502
* Allow as-patterns in unidirectional patttern synonymsSimon Peyton Jones2018-03-211-0/+18
| | | | | | | | | | | | | | This patch implements GHC Proposal #94, described here https://github.com/ghc-proposals/ghc-proposals/pull/94 The effect is simply to lift a totally-undocumented restriction to unidirecional pattern synonyms, namely that they can't have as-patterns or n+k patterns. The fix is easy: just remove the checks. I also took the opportunity to improve the manual entry for the semantics of pattern matching for pattern synonyms.
* relnotes: Fix parsing of Version: field from Cabal fileBen Gamari2018-03-191-2/+2
| | | | | | Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4491
* Add -flate-specialise which runs a later specialisation passMatthew Pickering2018-03-191-0/+14
| | | | | | | | | | | | | | | | | | | | | Runs another specialisation pass towards the end of the optimisation pipeline. This can catch specialisation opportunities which arose from the previous specialisation pass or other inlining. You might want to use this if you are you have a type class method which returns a constrained type. For example, a type class where one of the methods implements a traversal. It is not enabled by default or any optimisation level. Only by manually enabling the flag `-flate-specialise`. Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4457
* Fix typo in user guide about ConstraintKindsFrank Steffahn2018-03-191-1/+1
| | | The backslash currently in this type signature makes no sense. Without it, the example is fine.
* Implement -dword-hex-literalsAndrew Martin2018-03-191-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | Provide flag for showing showing Word# and Word64# as hexadecimal when dumping GHC core. The only affects Word, not Int, and it prefixes the hexadecimal with enough zeroes to make the total character count a power of two. For example: - 0x0C0C instead of 0xC0C - 0x00BA00BA instead of 0xBA00BA This also affects the presentation of Word# and Word64# in GHC's error messages. It is not expected that the flag will be used for this, but it is a side-effect worth noting. Test Plan: none Reviewers: bgamari, simonpj Reviewed By: simonpj Subscribers: simonpj, mpickering, rwbarton, thomie, carter, andrewthad GHC Trac Issues: #14872 Differential Revision: https://phabricator.haskell.org/D4465
* rts: Add --internal-counters RTS flag and several countersDouglas Wilson2018-03-191-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing internal counters: * gc_alloc_block_sync * whitehole_spin * gen[g].sync * gen[1].sync are now not shown in the -s report unless --internal-counters is also passed. If --internal-counters is passed we now show the counters above, reformatted, as well as several other counters. In particular, we now count the yieldThread() calls that SpinLocks do as well as their spins. The added counters are: * gc_spin (spin and yield) * mut_spin (spin and yield) * whitehole_threadPaused (spin only) * whitehole_executeMessage (spin only) * whitehole_lockClosure (spin only) * waitForGcThreadsd (spin and yield) As well as the following, which are not SpinLock-like things: * any_work * do_work * scav_find_work See the Note for descriptions of what these counters are. We add busy_wait_nops in these loops along with the counter increment where it was absent. Old internal counters output: ``` gc_alloc_block_sync: 0 whitehole_gc_spin: 0 gen[0].sync: 0 gen[1].sync: 0 ``` New internal counters output: ``` Internal Counters: Spins Yields gc_alloc_block_sync 323 0 gc_spin 9016713 752 mut_spin 57360944 47716 whitehole_gc 0 n/a whitehole_threadPaused 0 n/a whitehole_executeMessage 0 n/a whitehole_lockClosure 0 0 waitForGcThreads 2 415 gen[0].sync 6 0 gen[1].sync 1 0 any_work 2017 no_work 2014 scav_find_work 1004 ``` Test Plan: ./validate Check it builds with #define PROF_SPIN removed from includes/rts/Config.h Reviewers: bgamari, erikd, simonmar, hvr Reviewed By: simonmar Subscribers: rwbarton, thomie, carter GHC Trac Issues: #3553, #9221 Differential Revision: https://phabricator.haskell.org/D4302
* Remove outdated documentation bits concerning -Wmissing-methodsRyan Scott2018-03-082-17/+4
| | | | | | | | | | | | | | | | | | | In commit 503219e3e1667ac39607021b2d9586260fbab32b, we stopped suppressing `-Wmissing-methods` warnings on class methods whose names begin with an underscore. However, it seems the users' guide documentation concerning this was never updated. Let's do so. Test Plan: Read it Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #12959 Differential Revision: https://phabricator.haskell.org/D4476
* Error message and doc improvements for #14335Ömer Sinan Ağacan2018-03-081-0/+3
| | | | | | | | | | | | | | | | | | | | - Show a more friendly error message when -fplugin is used with -fexternal-interpreter - Add a few words to users guide about the interaction with -fplugin and -fexternal-interpreter - Update test for #14335 Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14335 Differential Revision: https://phabricator.haskell.org/D4456
* Add -fexternal-dynamic-refsSimon Marlow2018-03-082-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The `-dynamic` flag does two things: * In the code generator, it generates code designed to link against external shared libraries. References outside of the current module go through platform-specific indirection tables (e.g. the GOT on ELF). * It enables a "way", which changes which hi files we look for (`Foo.dyn_hi`) and which libraries we link against. Some specialised applications want the first of these without the second. (I could go into detail here but it's probably not all that important). This diff splits out the code-generation effects of `-dynamic` from the "way" parts of its behaviour, via a new flag `-fexternal-dynamic-refs`. Test Plan: validate Reviewers: niteria, bgamari, erikd Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4477
* Users Guide: Add that --numa is available on Windows tooSimon Jakobi2018-03-071-1/+1
| | | | Windows support was added in c93813d96b1da53a2ebd9c9ac5af6cc3e3443c43
* Fix a typo about pattern synonyms in documentation.HE, Tao2018-03-071-1/+1
|
* Correct -g flag descriptionBartosz Nitka2018-03-061-2/+3
| | | | | | | | | | | | | | | | Since 7aaeaf81ea95c36fe1dc4da449cf6092a792fd09 `-g1` and `-g2` are actually different. The tutorial below is correct. Test Plan: harbormaster Reviewers: bgamari, simonmar Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4471
* DynFlags: Support British spelling of GeneralisedNewtypeDerivingBen Gamari2018-03-022-1/+3
| | | | | | | | | | | | Reviewers: dfeuer Reviewed By: dfeuer Subscribers: dfeuer, rwbarton, thomie, carter GHC Trac Issues: #14819 Differential Revision: https://phabricator.haskell.org/D4422
* Improve exhaustive checking for guards in pattern bindings and MultiIf.HE, Tao2018-03-021-0/+16
| | | | | | | | | | | | | | | | | | | | | | | Previously we didn't do exhaustive checking on MultiIf expressions and guards in pattern bindings. We can construct the `LMatch` directly from GRHSs or [LHsExpr] (MultiIf's alts) then feed it to checkMatches, without construct the MatchGroup and using function `matchWrapper`. Signed-off-by: HE, Tao <sighingnow@gmail.com> Test Plan: make test TEST="T14773a T14773b" Reviewers: bgamari, RyanGlScott, simonpj Reviewed By: bgamari, simonpj Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14773 Differential Revision: https://phabricator.haskell.org/D4400
* Move Data.Functor.Contravariant from the contravariant package to base.Andrew Martin2018-03-021-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Move Data.Functor.Contravariant from the contravariant package to base. Since base is the bottom of the dependency hierarchy, several instances have been removed. They will need to be added to the following packages: transformers, StateVar, and possibly tagged. There may not actually have been any types from tagged that previous had instanced provided by this module though, since it may have only been used for Data.Proxy. Additionally, all CPP has been removed. Derived Typeable instances have been removed (since Typeable is now automatically derived for everything). The language extension Safe is still used, although it is unclear to ATM whether or not it is necessary. This resolves trac issue #14767. Test Plan: validate Reviewers: RyanGlScott, ekmett, hvr, bgamari Reviewed By: RyanGlScott Subscribers: rwbarton, thomie, ekmett, carter, RyanGlScott GHC Trac Issues: #14767 Differential Revision: https://phabricator.haskell.org/D4399
* Introduce the flag -dsuppress-timestamps to avoid timestamps in dumps.Andreas Klebinger2018-02-251-1/+8
| | | | | | | | | | | | | | | | | This makes it easier to diff dumps which are otherwise identical. Also updated the description of -dsuppress-all as parts of these also apply to stages other than core. Test Plan: Looking at dump result. Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4429
* Change how includes for input file directory worksTamar Christina2018-02-191-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GHC Used to only allow for one include mode, namely `-I`. The problem with `-I` includes is that it supercedes all other includes, including the system include paths. This is not a problem for paths requested by the user, but it is a problem for the ones we implicitly derive and add. In particular we add the source directory of the input file to the include path. This is problematic because it causes any file with the name of a system include, to inadvertently loop as the wrong file gets included. Since this is an implicitly include, and as far as I can tell, only done so local includes are found (as the sources given to GCC reside in a temp folder) then switch from `-I` to `-iquote`. This requires a submodule update for haddock Test Plan: ./validate Reviewers: austin, bgamari, hvr Reviewed By: bgamari Subscribers: carter, rwbarton, thomie GHC Trac Issues: #14312 Differential Revision: https://phabricator.haskell.org/D4080
* StgLint overhaulÖmer Sinan Ağacan2018-02-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Remove all type checks - Check two STG invariants (no unboxed let bindings, variables defined before used) and post-unarisation invariants. See the module header and #14787. This version validates with `-dstg-lint` added to `GhcStage2HcOpts` and `GhcLibHcOpts` and `EXTRA_HC_OPTS`. Unarise changes: - `unariseConArgBinder` and `unariseFunArgBinder` functions were almost the same; only difference was when unarising fun args we keep void args while in con args we drop them. A new function `unariseArgBinder` added with a `Bool` argument for whether we're unarising a con arg. `unariseConArgBinder` and `unariseFunArgBinder` are now defined as unariseConArgBinder = unarsieArgBinder True -- data con unariseFunArgBinder = unariseArgBinder False -- not data con - A bug in `unariseConArgBinder` and `unariseFunArgBinder` (which are just calls to `unariseArgBinder` now) that invalidated the post-unarise invariants when the argument has single type rep (i.e. `length (typePrimRep x) == 1`) fixed. This isn't a correctness issue (it's fine not to unarise if a variable is already represented as single value), but it triggers StgLint. Test Plan: - Pass testsuite with `-dstg-lint` [done] - Boot stage2 (including libraries) with `-dstg-lint` [done] Reviewers: simonpj, bgamari Reviewed By: bgamari Subscribers: duog, rwbarton, thomie, carter GHC Trac Issues: #14787 Differential Revision: https://phabricator.haskell.org/D4404
* Remove doubled wordsAdam Sandberg Eriksson2018-02-182-4/+3
| | | | | | | | | | Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4368
* Add valid refinement substitution suggestions for typed holesMatthías Páll Gissurarson2018-02-181-2/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds valid refinement substitution suggestions for typed holes and documentation thereof. Inspired by Agda's refinement facilities, this extends the typed holes feature to be able to search for valid refinement substitutions, which are substitutions that have one or more holes in them. When the flag `-frefinement-level-substitutions=n` where `n > 0` is passed, we also look for valid refinement substitutions, i.e. substitutions that are valid, but adds more holes. Consider the following: f :: [Integer] -> Integer f = _ Here the valid substitutions suggested will be (with the new `-funclutter-valid-substitutions` flag for less verbosity set): ``` Valid substitutions include f :: [Integer] -> Integer product :: forall (t :: * -> *). Foldable t => forall a. Num a => t a -> a sum :: forall (t :: * -> *). Foldable t => forall a. Num a => t a -> a maximum :: forall (t :: * -> *). Foldable t => forall a. Ord a => t a -> a minimum :: forall (t :: * -> *). Foldable t => forall a. Ord a => t a -> a head :: forall a. [a] -> a (Some substitutions suppressed; use -fmax-valid-substitutions=N or -fno-max-valid-substitutions) ``` When the `-frefinement-level-substitutions=1` flag is given, we additionally compute and report valid refinement substitutions: ``` Valid refinement substitutions include foldl1 _ :: forall (t :: * -> *). Foldable t => forall a. (a -> a -> a) -> t a -> a foldr1 _ :: forall (t :: * -> *). Foldable t => forall a. (a -> a -> a) -> t a -> a head _ :: forall a. [a] -> a last _ :: forall a. [a] -> a error _ :: forall (a :: TYPE r). GHC.Stack.Types.HasCallStack => [Char] -> a errorWithoutStackTrace _ :: forall (a :: TYPE r). [Char] -> a (Some refinement substitutions suppressed; use -fmax-refinement-substitutions=N or -fno-max-refinement-substitutions) ``` Which are substitutions with holes in them. This allows e.g. beginners to discover the fold functions and similar. We find these refinement suggestions by considering substitutions that don't fit the type of the hole, but ones that would fit if given an additional argument. We do this by creating a new type variable with newOpenFlexiTyVarTy (e.g. `t_a1/m[tau:1]`), and then considering substitutions of the type `t_a1/m[tau:1] -> v` where `v` is the type of the hole. Since the simplifier is free to unify this new type variable with any type (and it is cloned before each check to avoid side-effects), we can now discover any identifiers that would fit if given another identifier of a suitable type. This is then generalized so that we can consider any number of additional arguments by setting the `-frefinement-level-substitutions` flag to any number, and then considering substitutions like e.g. `foldl _ _` with two additional arguments. This can e.g. help beginners discover the `fold` functions. This could also help more advanced users figure out which morphisms they can use when arrow chasing. Then you could write `m = _ . m2 . m3` where `m2` and `m3` are some morphisms, and not only get exact fits, but also help in finding morphisms that might get you a little bit closer to where you want to go in the diagram. Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4357
* Various documentation improvementsSergey Vinokurov2018-02-141-1/+1
| | | | | | | | | | | | | | | * Fix missing code example in changelog for 8.4.1 * List 'setEnv' as opposite of 'getEnv' It seems best to direct users to use 'System.Environment.setEnv' rather than 'System.Posix.Env.putEnv'. This is due to 'setEnv' being located in the same module as 'getEnv' and my virtue of working on Windows platform, whereas 'putEnv' does not have that quality because it's part of the 'unix' package. * Reflect in docs the fact that 'readMVar' is not a composition of 'takeMVVar' and 'putMVar' any more
* Raise parse error for `data T where`.HE, Tao2018-02-131-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | Empty GADTs data declarations can't be identified in type checker. This patch adds additional checks in parser and raise a parse error when encounter empty GADTs declarations but extension `GADTs` is not enabled. Only empty declarations are checked in parser to avoid affecting existing error messages related to missing GADTs extension. This patch should fix issue 8258. Signed-off-by: HE, Tao <sighingnow@gmail.com> Test Plan: make test TEST="T8258 T8258NoGADTs" Reviewers: bgamari, mpickering, alanz, RyanGlScott Reviewed By: bgamari, RyanGlScott Subscribers: adamse, RyanGlScott, rwbarton, thomie, mpickering, carter GHC Trac Issues: #8258 Differential Revision: https://phabricator.haskell.org/D4350
* Make ($!) representation-polymorphicDavid Feuer2018-02-121-0/+2
| | | | | | | | | | | | | Now that `($)` is representation-polymorphic, `($!)` should surely follow suit. Reviewers: hvr, bgamari, simonpj Reviewed By: bgamari, simonpj Subscribers: simonpj, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4382
* Improve unboxed sum documentationDavid Feuer2018-02-051-28/+39
| | | | | | | | | | | | | | | | | * Clarify the representation of sums without fields. * Try to improve language, clarity, and examples. Fixes #14752 Reviewers: osa1, bgamari Reviewed By: osa1 Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14752 Differential Revision: https://phabricator.haskell.org/D4379
* Flag `-fdefer-typed-holes` also implies `-fdefer-out-of-scope-variables`.HE, Tao2018-02-021-1/+1
| | | | | | | | | | Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4361
* Add -ddump-ds-preoptSimon Peyton Jones2018-02-011-3/+8
| | | | | | | | | | | | | This allows you to see the output immediately after desugaring but before any optimisation. I've wanted this for some time, but I was triggered into action by Trac #13032 comment:9. Interestingly, the change means that with -dcore-lint we will now Lint the output before the very simple optimiser; and this showed up Trac #14749. But that's not the fault of -ddump-ds-preopt!
* Implement BlockArguments (#10843)Takano Akio2018-01-312-6/+98
| | | | | | | | | | | | | | | | | | | | | | | | This patch implements the BlockArguments extension, as proposed at https://github.com/ghc-proposals/ghc-proposals/pull/90. It also fixes #10855 as a side-effect. This patch adds a large number of shift-reduce conflicts to the parser. All of them concern the ambiguity as to where constructs like `if` and `let` end. Fortunately they are resolved correctly by preferring shift. The patch is based on @gibiansky's ArgumentDo implementation (D1219). Test Plan: ./validate Reviewers: goldfire, bgamari, alanz, mpickering Reviewed By: bgamari, mpickering Subscribers: Wizek, dfeuer, gibiansky, rwbarton, thomie, mpickering, carter GHC Trac Issues: #10843, #10855 Differential Revision: https://phabricator.haskell.org/D4260
* Sort valid substitutions for typed holes by "relevance"Matthías Páll Gissurarson2018-01-262-58/+257
| | | | | | | | | | | | | | | | | | | | | | | | | This is an initial attempt at tackling the issue of how to order the suggestions provided by the valid substitutions checker, by sorting them by creating a graph of how they subsume each other. We'd like to order them in such a manner that the most "relevant" suggestions are displayed first, so that the suggestion that the user might be looking for is displayed before more far-fetched suggestions (and thus also displayed when they'd otherwise be cut-off by the `-fmax-valid-substitutions` limit). The previous ordering was based on the order in which the elements appear in the list of imports, which I believe is less correlated with relevance than this ordering. A drawback of this approach is that, since we now want to sort the elements, we can no longer "bail out early" when we've hit the `-fmax-valid-substitutions` limit. Reviewers: bgamari, dfeuer Reviewed By: dfeuer Subscribers: dfeuer, rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4326
* Implement underscores in numeric literals (NumericUnderscores extension)Takenobu Tani2018-01-211-0/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement the proposal of underscores in numeric literals. Underscores in numeric literals are simply ignored. The specification of the feature is available here: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/000 9-numeric-underscores.rst For a discussion of the various choices: https://github.com/ghc-proposals/ghc-proposals/pull/76 Implementation detail: * Added dynamic flag * `NumericUnderscores` extension flag is added for this feature. * Alex "Regular expression macros" in Lexer.x * Add `@numspc` (numeric spacer) macro to represent multiple underscores. * Modify `@decimal`, `@decimal`, `@binary`, `@octal`, `@hexadecimal`, `@exponent`, and `@bin_exponent` macros to include `@numspc`. * Alex "Rules" in Lexer.x * To be simpler, we have only the definitions with underscores. And then we have a separate function (`tok_integral` and `tok_frac`) that validates the literals. * Validation functions in Lexer.x * `tok_integral` and `tok_frac` functions validate whether contain underscores or not. If `NumericUnderscores` extensions are not enabled, check that there are no underscores. * `tok_frac` function is created by merging `strtoken` and `init_strtoken`. * `init_strtoken` is deleted. Because it is no longer used. * Remove underscores from target literal string * `parseUnsignedInteger`, `readRational__`, and `readHexRational} use the customized `span'` function to remove underscores. * Added Testcase * testcase for NumericUnderscores enabled. NumericUnderscores0.hs and NumericUnderscores1.hs * testcase for NumericUnderscores disabled. NoNumericUnderscores0.hs and NoNumericUnderscores1.hs * testcase to invalid pattern for NumericUnderscores enabled. NumericUnderscoresFail0.hs and NumericUnderscoresFail1.hs Test Plan: `validate` including the above testcase Reviewers: goldfire, bgamari Reviewed By: bgamari Subscribers: carter, rwbarton, thomie GHC Trac Issues: #14473 Differential Revision: https://phabricator.haskell.org/D4235
* tentative improvement to callstack docsAlp Mestanogullari2018-01-211-14/+53
| | | | | | | | | | | | | | | | | | This is an attempt at clarifying the docs for HasCallStack in both the user guide and libraries/base/GHC/Stack/Types.hs. The example used right now is built around an hypothetical 'error' function that doesn't itself print call stacks, and the fact that this doesn't hold makes it all confusing, see #14635. Reviewers: hvr, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14635 Differential Revision: https://phabricator.haskell.org/D4317
* Add flag -fno-itMatthew Pickering2018-01-151-0/+14
| | | | | | | | | | | | | | | | This flag stops ghci creating the special variable `it` after evaluating an expression. This stops ghci leaking as much memory when evaluating expressions. See #14336 Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14336 Differential Revision: https://phabricator.haskell.org/D4299
* Support LIBRARY_PATH and LD_LIBRARY_PATH in rtsBen Gamari2018-01-152-7/+21
| | | | | | | | | | | | | | | | | | | | | | | | | `LIBRARY_PATH` is used to find libraries and other link artifacts while `LD_LIBRARY_PATH` is used to find shared libraries by the loader. Due to an implementation detail on Windows, using `LIBRARY_PATH` will automatically add the path of any library found to the loader's path. So in that case `LD_LIBRARY_PATH` won't be needed. Test Plan: ./validate along with T14611 which has been made Windows only due to linux using the system linker/loader by default. So I feel a testcase there is unwarranted as the support is indirect via glibc. Reviewers: hvr, bgamari, erikd, simonmar, RyanGlScott Reviewed By: RyanGlScott Subscribers: RyanGlScott, rwbarton, thomie, carter GHC Trac Issues: #14611 Differential Revision: https://phabricator.haskell.org/D4275
* Tweak link order slightly to prefer user shared libs before system ones.Tamar Christina2018-01-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | We currently always prefer shared libraries before import libraries and static libraries. This is because they're faster to load. The problem is when shared library are installed in the Windows directory. These would supersede any user specified ones. This is bad because e.g. Windows now ships icuuc, but an old version. If you try to use -licuuc then it would pick the Windows one instead of your user specified one. This patch slighly tweaks the ordering so user paths get prefered. Test Plan: ./validate Reviewers: RyanGlScott, hvr, bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14456 Differential Revision: https://phabricator.haskell.org/D4274
* Rename -frule-check to -drule-check and documentMatthew Pickering2018-01-151-0/+13
| | | | | | | | | | Reviewers: bgamari Reviewed By: bgamari Subscribers: rwbarton, thomie, carter Differential Revision: https://phabricator.haskell.org/D4256
* Typos in commentsGabor Greif2018-01-031-1/+1
|
* No deferred type errors under a forallSimon Peyton Jones2018-01-031-0/+23
| | | | | | | As Trac #14605 showed, we can't defer a type error under a 'forall' (when unifying two forall types). The fix is simple.
* Prevent "C--" translating to "C–" in the User's Guide.Steven Shaw2018-01-023-37/+37
| | | | i.e. escape "--" so that it doesn't translate to an "en dash".
* Fix sign error in kelvinToC.Galen Huntington2018-01-021-1/+1
|
* users-guide: Fix markupBen Gamari2018-01-021-4/+4
|
* Add GHC 8.6.1 release notesTamar Christina2017-12-231-0/+85
|
* relnotes: Fix typo in pattern synonym exampleBen Gamari2017-12-221-2/+2
|
* Document ScopedTypeVariables' interaction with nested forallsRyan Scott2017-12-201-1/+21
| | | | | | | | | | | | | | | | | | | | | | Summary: This documents the status quo with regards to how `ScopedTypeVariables` brings into scope type variables that are quantified by nested `forall`s (that is to say, it doesn't). This takes the prose in https://ghc.haskell.org/trac/ghc/ticket/14288#comment:5 and enshrines it into the users' guide. Test Plan: Read it Reviewers: simonpj, bgamari Reviewed By: simonpj Subscribers: rwbarton, thomie, carter GHC Trac Issues: #14288 Differential Revision: https://phabricator.haskell.org/D4272
View Lorry Controller Status