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* Introduce -dlint flagBen Gamari2021-12-211-0/+12
| | | | | | As suggested in #20601, this is a short-hand for enabling the usual GHC-internal sanity checks one typically leans on when debugging runtime crashes.
* Rename -fcatch-bottoms to -fcatch-nonexhaustive-casesBen Gamari2021-12-211-1/+1
| | | | As noted in #20601, the previous name was rather misleading.
* codeGen: Introduce flag to bounds-check array accessesBen Gamari2021-12-211-0/+12
| | | | | | | Here we introduce code generator support for instrument array primops with bounds checking, enabled with the `-fcheck-prim-bounds` flag. Introduced to debug #20769.
* Plugin load order should follow the commandline order (fixes #17884)Andrei Barbu2021-12-151-3/+5
| | | | | | | In the past the order was reversed because flags are consed onto a list. No particular behavior was documented. We now reverse the flags and document the behavior.
* ghc-bin: Add --merge-objs modeBen Gamari2021-12-142-0/+23
| | | | | | | | | | This adds a new mode, `--merge-objs`, which can be used to produce merged GHCi library objects. As future work we will rip out the object-merging logic in Hadrian and Cabal and instead use this mode. Closes #20712.
* users-guide: Fix documentation for -shared flagBen Gamari2021-12-141-3/+4
| | | | | | This flag was previously called `--mk-dll`. It was renamed to `-shared` in b562cbe381d54e08dcafa11339e9a82e781ad557 but the documentation wasn't updated to match.
* Ghci environment: Do not remove shadowed idsJoachim Breitner2021-12-141-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Names defined earier but shadowed need to be kept around, e.g. for type signatures: ``` ghci> data T = T ghci> let t = T ghci> data T = T ghci> :t t t :: Ghci1.T ``` and indeed they can be used: ``` ghci> let t2 = Ghci1.T :: Ghci1.T ghci> :t t2 t2 :: Ghci1.T ``` However, previously this did not happen for ids (non-types), although they are still around under the qualified name internally: ``` ghci> let t = "other t" ghci> t' <interactive>:8:1: error: • Variable not in scope: t' • Perhaps you meant one of these: ‘Ghci2.t’ (imported from Ghci2), ‘t’ (line 7), ‘t2’ (line 5) ghci> Ghci2.t <interactive>:9:1: error: • GHC internal error: ‘Ghci2.t’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [] • In the expression: Ghci2.t In an equation for ‘it’: it = Ghci2.t ``` This fixes the problem by simply removing the code that tries to remove shadowed ids from the environment. Now you can refer to shadowed ids using `Ghci2.t`, just like you can do for data and type constructors. This simplifies the code, makes terms and types more similar, and also fixes #20455. Now all names ever defined in GHCi are in `ic_tythings`, which is printed by `:show bindings`. But for that commands, it seems to be more ergonomic to only list those bindings that are not shadowed. Or, even if it is not more ergonomic, it’s the current behavour. So let's restore that by filtering in `icInScopeTTs`. Of course a single `TyThing` can be associated with many names. We keep it it in the bindings if _any_ of its names are still visible unqualifiedly. It's a judgement call. This commit also turns a rather old comment into a test files. The comment is is rather stale and things are better explained elsewhere. Fixes #925. Two test cases are regressing: T14052(ghci) ghc/alloc 2749444288.0 12192109912.0 +343.4% BAD T14052Type(ghci) ghc/alloc 7365784616.0 10767078344.0 +46.2% BAD This is not unexpected; the `ic_tythings list grows` a lot more if we don’t remove shadowed Ids. I tried to alleviate it a bit with earlier MRs, but couldn’t make up for it completely. Metric Increase: T14052 T14052Type
* docs: Drop old release notesBen Gamari2021-12-103-929/+0
| | | | Closes #20786
* Add `Opt_CoreConstantFolding` to turn on constant folding (#20500)Gergo ERDI2021-12-091-0/+11
| | | | | Previously, `-O1` and `-O2`, by way of their effect on the compilation pipeline, they implicitly turned on constant folding
* More permissive parsing of higher-rank type IPssheaf2021-12-071-0/+8
| | | | | | | | | | | | | | | | | The parser now accepts implicit parameters with higher-rank types, such as `foo :: (?ip :: forall a. a -> a) => ...` Before this patch, we instead insisted on parentheses like so: `foo :: (?ip :: (forall a. a -> a)) => ...` The rest of the logic surrounding implicit parameters is unchanged; in particular, even with ImpredicativeTypes, this idiom is not likely to be very useful. Fixes #20654
* rts: +RTS -DL should imply +RTS -DlBen Gamari2021-12-071-0/+1
| | | | | Otherwise the user may be surprised by the missing context provided by the latter.
* Fix user-guide typoViktor Dukhovni2021-12-071-1/+1
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* Add section to the user guide about OS memory usageMatthew Pickering2021-12-063-2/+110
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* Revert "Data.List specialization to []"Matthew Pickering2021-12-031-2/+7
| | | | | | | | | | This reverts commit bddecda1a4c96da21e3f5211743ce5e4c78793a2. This implements the first step in the plan formulated in #20025 to improve the communication and migration strategy for the proposed changes to Data.List. Requires changing the haddock submodule to update the test output.
* users-guide: Describe requirements of DWARF unwindingBen Gamari2021-12-011-0/+10
| | | | As requested in #20702
* user-guide: Fix :since: of -XCApiFFIBen Gamari2021-12-011-1/+1
| | | | Closes #20504.
* Dump non-module specific info to file #20316Carrie Xu2021-12-011-4/+8
| | | | | | | | | - Change the dumpPrefix to FilePath, and default to non-module - Add dot to seperate dump-file-prefix and suffix - Modify user guide to introduce how dump files are named - This commit does not affect Ghci dump file naming. See also #17500
* docs/users_guide/bugs.rst: RewordingAnton-Latukha2021-11-291-3/+3
| | | | | | | | It is either "slightly" || "significantly". If it is "bogus" - then no quotes around "optimization" & overall using word "bogus" or use quotes in that way in documentation is... Instead, something like "hack" or "heuristic" can be used there.
* Allow boring class declarations in hs-boot filessheaf2021-11-251-3/+25
| | | | | | | | | | | | | | | | | | | | | | | There are two different ways of declaring a class in an hs-boot file: - a full declaration, where everything is written as it is in the .hs file, - an abstract declaration, where class methods and superclasses are left out. However, a declaration with no methods and a trivial superclass, such as: class () => C a was erroneously considered to be an abstract declaration, because the superclass is trivial. This is remedied by a one line fix in GHC.Tc.TyCl.tcClassDecl1. This patch also further clarifies the documentation around class declarations in hs-boot files. Fixes #20661, #20588.
* Add specific optimization flag for Cmm control flow analysis (#20500)Gergo ERDI2021-11-251-1/+11
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* Add specific optimization flag for fast PAP calls (#6084, #20500)Gergo ERDI2021-11-251-0/+1
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* Misc cleanupKrzysztof Gogolewski2021-11-254-36/+12
| | | | | | | | | | | | | | | | | | | | | * Remove `getTag_RDR` (unused), `tidyKind` and `tidyOpenKind` (already available as `tidyType` and `tidyOpenType`) * Remove Note [Explicit Case Statement for Specificity]. Since 0a709dd9876e40 we require GHC 8.10 for bootstrapping. * Change the warning to `cmpAltCon` to a panic. This shouldn't happen. If it ever does, the code was wrong anyway: it shouldn't always return `LT`, but rather `LT` in one case and `GT` in the other case. * Rename `verifyLinearConstructors` to `verifyLinearFields` * Fix `Note [Local record selectors]` which was not referenced * Remove vestiges of `type +v` * Minor fixes to StaticPointers documentation, part of #15603
* Add a warning for GADT match + NoMonoLocalBinds (#20485)Krzysztof Gogolewski2021-11-231-1/+27
| | | | | | | | | Previously, it was an error to pattern match on a GADT without GADTs or TypeFamilies. This is now allowed. Instead, we check the flag MonoLocalBinds; if it is not enabled, we issue a warning, controlled by -Wgadt-mono-local-binds. Also fixes #20485: pattern synonyms are now checked too.
* Implement -Wforall-identifier (#20609)Vladislav Zavialov2021-11-121-0/+28
| | | | | | | | | | In accordance with GHC Proposal #281 "Visible forall in types of terms": For three releases before this change takes place, include a new warning -Wforall-identifier in -Wdefault. This warning will be triggered at definition sites (but not use sites) of forall as an identifier. Updates the haddock submodule.
* Only pass -pie, -no-pie when linkingMatthew Bauer2021-11-111-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, these flags were passed when both compiling and linking code. However, `-pie` and `-no-pie` are link-time-only options. Usually, this does not cause issues, but when using Clang with `-Werror` set results in errors: clang: error: argument unused during compilation: '-nopie' [-Werror,-Wunused-command-line-argument] This is unused by Clang because this flag has no effect at compile time (it’s called `-nopie` internally by Clang but called `-no-pie` in GHC for compatibility with GCC). Just passing these flags at linking time resolves this. Additionally, update #15319 hack to look for `-pgml` instead. Because of the main change, the value of `-pgmc` does not matter when checking for the workaround of #15319. However, `-pgml` *does* still matter as not all `-pgml` values support `-no-pie`. To cover all potential values, we assume that no custom `-pgml` values support `-no-pie`. This means that we run the risk of not using `-no-pie` when it is otherwise necessary for in auto-hardened toolchains! This could be a problem at some point, but this workaround was already introduced in 8d008b71 and we might as well continue supporting it. Likewise, mark `-pgmc-supports-no-pie` as deprecated and create a new `-pgml-supports-no-pie`.
* Clarify hs-boot file default method restrictionssheaf2021-11-101-4/+6
| | | | | | | | | | | | | The user guide wrongly stated that default methods should not be included in hs-boot files. In fact, if the class is not left abstract (no methods, no superclass constraints, ...) then the defaults must be provided and match with those given in the .hs file. We add some tests for this, as there were no tests in the testsuite that gave rise to the "missing default methods" error. Fixes #20588
* Improvements to rank_polymorphism.rstsheaf2021-11-101-11/+21
| | | | | | | | | | | | - rename the function f4 to h1 for consistency with the naming convention - be more explicit about the difference between `Int -> (forall a. a -> a)` and `forall a. Int -> (a -> a)` - reorder the section to make it flow better Fixes #20585
* User's guide: data family kind-inference changessheaf2021-10-291-3/+12
| | | | | | | | Explain that the kind of a data family instance must now be fully determined by the header of the instance, and how one might migrate code to account for this change. Fixes #20527
* Don't default type variables in type familiessheaf2021-10-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the following defaulting of type variables in type and data families: - type variables of kind RuntimeRep defaulting to LiftedRep - type variables of kind Levity defaulting to Lifted - type variables of kind Multiplicity defaulting to Many It does this by passing "defaulting options" to the `defaultTyVars` function; when calling from `tcTyFamInstEqnGuts` or `tcDataFamInstHeader` we pass options that avoid defaulting. This avoids wildcards being defaulted, which caused type families to unexpectedly fail to reduce. Note that kind defaulting, applicable only with -XNoPolyKinds, is not changed by this patch. Fixes #17536 ------------------------- Metric Increase: T12227 -------------------------
* Warn if unicode bidirectional formatting characters are found in the source ↵Zubin Duggal2021-10-261-0/+18
| | | | (#20263)
* DmdAnal: Implement Boxity Analysis (#19871)Sebastian Graf2021-10-241-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes some abundant reboxing of `DynFlags` in `GHC.HsToCore.Match.Literal.warnAboutOverflowedLit` (which was the topic of #19407) by introducing a Boxity analysis to GHC, done as part of demand analysis. This allows to accurately capture ad-hoc unboxing decisions previously made in worker/wrapper in demand analysis now, where the boxity info can propagate through demand signatures. See the new `Note [Boxity analysis]`. The actual fix for #19407 is described in `Note [No lazy, Unboxed demand in demand signature]`, but `Note [Finalising boxity for demand signature]` is probably a better entry-point. To support the fix for #19407, I had to change (what was) `Note [Add demands for strict constructors]` a bit (now `Note [Unboxing evaluated arguments]`). In particular, we now take care of it in `finaliseBoxity` (which is only called from demand analaysis) instead of `wantToUnboxArg`. I also had to resurrect `Note [Product demands for function body]` and rename it to `Note [Unboxed demand on function bodies returning small products]` to avoid huge regressions in `join004` and `join007`, thereby fixing #4267 again. See the updated Note for details. A nice side-effect is that the worker/wrapper transformation no longer needs to look at strictness info and other bits such as `InsideInlineableFun` flags (needed for `Note [Do not unbox class dictionaries]`) at all. It simply collects boxity info from argument demands and interprets them with a severely simplified `wantToUnboxArg`. All the smartness is in `finaliseBoxity`, which could be moved to DmdAnal completely, if it wasn't for the call to `dubiousDataConInstArgTys` which would be awkward to export. I spent some time figuring out the reason for why `T16197` failed prior to my amendments to `Note [Unboxing evaluated arguments]`. After having it figured out, I minimised it a bit and added `T16197b`, which simply compares computed strictness signatures and thus should be far simpler to eyeball. The 12% ghc/alloc regression in T11545 is because of the additional `Boxity` field in `Poly` and `Prod` that results in more allocation during `lubSubDmd` and `plusSubDmd`. I made sure in the ticky profiles that the number of calls to those functions stayed the same. We can bear such an increase here, as we recently improved it by -68% (in b760c1f). T18698* regress slightly because there is more unboxing of dictionaries happening and that causes Lint (mostly) to allocate more. Fixes #19871, #19407, #4267, #16859, #18907 and #13331. Metric Increase: T11545 T18698a T18698b Metric Decrease: T12425 T16577 T18223 T18282 T4267 T9961
* Introduce Concrete# for representation polymorphism checkssheaf2021-10-172-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | PHASE 1: we never rewrite Concrete# evidence. This patch migrates all the representation polymorphism checks to the typechecker, using a new constraint form Concrete# :: forall k. k -> TupleRep '[] Whenever a type `ty` must be representation-polymorphic (e.g. it is the type of an argument to a function), we emit a new `Concrete# ty` Wanted constraint. If this constraint goes unsolved, we report a representation-polymorphism error to the user. The 'FRROrigin' datatype keeps track of the context of the representation-polymorphism check, for more informative error messages. This paves the way for further improvements, such as allowing type families in RuntimeReps and improving the soundness of typed Template Haskell. This is left as future work (PHASE 2). fixes #17907 #20277 #20330 #20423 #20426 updates haddock submodule ------------------------- Metric Decrease: T5642 -------------------------
* Null eventlog writerOleg Grenrus2021-10-151-0/+8
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* Reject GADT pattern matches in arrow notationsheaf2021-10-091-0/+15
| | | | | | | | | | | | Tickets #20469 and #20470 showed that the current implementation of arrows is not at all up to the task of supporting GADTs: GHC produces ill-scoped Core programs because it doesn't propagate the evidence introduced by a GADT pattern match. For the time being, we reject GADT pattern matches in arrow notation. Hopefully we are able to add proper support for GADTs in arrows in the future.
* Add defaulting plugins.Andrei Barbu2021-10-082-0/+63
| | | | | | | | | | | | | | | Like the built-in type defaulting rules these plugins can propose candidates to resolve ambiguous type variables. Machine learning and other large APIs like those for game engines introduce new numeric types and other complex typed APIs. The built-in defaulting mechanism isn't powerful enough to resolve ambiguous types in these cases forcing users to specify minutia that they might not even know how to do. There is an example defaulting plugin linked in the documentation. Applications include defaulting the device a computation executes on, if a gradient should be computed for a tensor, or the size of a tensor. See https://github.com/ghc-proposals/ghc-proposals/pull/396 for details.
* Fix rst syntax mistakes in release notesJoachim Breitner2021-10-071-3/+3
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* Disable -dynamic-too if -dynamic is also passedMatthew Pickering2021-10-061-0/+2
| | | | | | | | | | | Before if you passed both options then you would generate two identical hi/dyn_hi and o/dyn_o files, both in the dynamic way. It's better to warn this is happening rather than duplicating the work and causing potential confusion. -dynamic-too should only be used with -static. Fixes #20436
* Document interaction between unsafe FFI and GCAlexander Kjeldaas2021-09-291-5/+23
| | | | | In the multi-threaded RTS this can lead to hard to debug performance issues.
* Documented yet undocumented dump flags #18641Benjamin Maurer2021-09-282-6/+38
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* Remove outdated note about pragma layouttaylorfausak2021-09-281-3/+1
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* Add `-dsuppress-core-sizes` flag (#20342)Sylvain Henry2021-09-281-0/+8
| | | | | This flag is used to remove the output of core stats per binding in Core dumps.
* Remove unused, undocumented debug/dump flag `-ddump-vt-trace`. See 20403.Benjamin Maurer2021-09-221-1/+0
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* users-guide: Improve documentation of ticky eventsBen Gamari2021-09-183-1/+13
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* Add doc for -dyno, -dynosuf, -dynhisufZiyang Liu2021-09-172-3/+26
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* Ensure .dyn_hi doesn't overwrite .hiZiyang Liu2021-09-171-1/+9
| | | | | | | | This commit fixes the following bug: when `outputHi` is set, and both `.dyn_hi` and `.hi` are needed, both would be written to `outputHi`, causing `.dyn_hi` to overwrite `.hi`. This causes subsequent `readIface` to fail - "mismatched interface file profile tag (wanted "", got "dyn")" - triggering unnecessary rebuild.
* driver: -M allow omitting the -dep-suffix (means empty) (fix #15483)Artem Pelenitsyn2021-09-171-3/+2
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* Emit warning if bang is applied to unlifted typesTito Sacchi2021-09-172-0/+20
| | | | | | | | | | | | | | | | GHC will trigger a warning similar to the following when a strictness flag is applied to an unlifted type (primitive or defined with the Unlifted* extensions) in the definition of a data constructor. Test.hs:7:13: warning: [-Wredundant-strictness-flags] • Strictness flag has no effect on unlifted type ‘Int#’ • In the definition of data constructor ‘TestCon’ In the data type declaration for ‘Test’ | 7 | data Test = TestCon !Int# | ^^^^^^^^^^^^^ Fixes #20187
* Improve error messages involving operators from Data.Type.OrdChristiaan Baaij2021-09-171-0/+4
| | | | Fixes #20009
* Documentation: use https linksKrzysztof Gogolewski2021-09-0835-85/+85
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* Minor doc fixesKrzysztof Gogolewski2021-09-087-90/+56
| | | | | | | | | | | | | - Fix markup in 9.4 release notes - Document -ddump-cs-trace - Mention that ImpredicativeTypes is really supported only since 9.2 - Remove "There are some restrictions on the use of unboxed tuples". This used to be a list, but all those restrictions were removed. - Mark -fimplicit-import-qualified as documented - Remove "The :main and :run command" - duplicated verbatim in options - Avoid calling "main" a function (cf. #7816) - Update System.getArgs: the old location was before hierarchical modules - Note that multiplicity multiplication is not supported (#20319)
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