summaryrefslogtreecommitdiff
path: root/testsuite/tests/ghci.debugger/scripts
Commit message (Collapse)AuthorAgeFilesLines
* Change `Backend` type and remove direct dependencieswip/backend-as-recordNorman Ramsey2022-05-211-1/+1
| | | | | | | | | | | | | | | | | | | With this change, `Backend` becomes an abstract type (there are no more exposed value constructors). Decisions that were formerly made by asking "is the current back end equal to (or different from) this named value constructor?" are now made by interrogating the back end about its properties, which are functions exported by `GHC.Driver.Backend`. There is a description of how to migrate code using `Backend` in the user guide. Clients using the GHC API can find a backdoor to access the Backend datatype in GHC.Driver.Backend.Internal. Bumps haddock submodule. Fixes #20927
* Two small improvements in the SimplifierSimon Peyton Jones2022-02-022-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As #20941 describes, this patch implements a couple of small fixes to the Simplifier. They make a difference principally with -O0, so few people will notice. But with -O0 they can reduce the number of Simplifer iterations. * In occurrence analysis we avoid making x = (a,b) into a loop breaker because we want to be able to inline x, or (more likely) do case-elimination. But HEAD does not treat x = let y = blah in (a,b) in the same way. We should though, because we are going to float that y=blah out of the x-binding. A one-line fix in OccurAnal. * The crucial function exprIsConApp_maybe uses getUnfoldingInRuleMatch (rightly) but the latter was deeply strange. In HEAD, if rule-rewriting was off (-O0) we only looked inside stable unfoldings. Very stupid. The patch simplifies. * I also noticed that in simplStableUnfolding we were failing to delete the DFun binders from the usage. So I added that. Practically zero perf change across the board, except that we get more compiler allocation in T3064 (which is compiled with -O0). There's a good reason: we get better code. But there are lots of other small compiler allocation decreases: Metrics: compile_time/bytes allocated --------------------- Baseline Test Metric value New value Change ----------------------------------------------------------------- PmSeriesG(normal) ghc/alloc 44,260,817 44,184,920 -0.2% PmSeriesS(normal) ghc/alloc 52,967,392 52,891,632 -0.1% PmSeriesT(normal) ghc/alloc 75,498,220 75,421,968 -0.1% PmSeriesV(normal) ghc/alloc 52,341,849 52,265,768 -0.1% T10421(normal) ghc/alloc 109,702,291 109,626,024 -0.1% T10421a(normal) ghc/alloc 76,888,308 76,809,896 -0.1% T10858(normal) ghc/alloc 125,149,038 125,073,648 -0.1% T11276(normal) ghc/alloc 94,159,364 94,081,640 -0.1% T11303b(normal) ghc/alloc 40,230,059 40,154,368 -0.2% T11822(normal) ghc/alloc 107,424,540 107,346,088 -0.1% T12150(optasm) ghc/alloc 76,486,339 76,426,152 -0.1% T12234(optasm) ghc/alloc 55,585,046 55,507,352 -0.1% T12425(optasm) ghc/alloc 88,343,288 88,265,312 -0.1% T13035(normal) ghc/alloc 98,919,768 98,845,600 -0.1% T13253-spj(normal) ghc/alloc 121,002,153 120,851,040 -0.1% T16190(normal) ghc/alloc 290,313,131 290,074,152 -0.1% T16875(normal) ghc/alloc 34,756,121 34,681,440 -0.2% T17836b(normal) ghc/alloc 45,198,100 45,120,288 -0.2% T17977(normal) ghc/alloc 39,479,952 39,404,112 -0.2% T17977b(normal) ghc/alloc 37,213,035 37,137,728 -0.2% T18140(normal) ghc/alloc 79,430,588 79,350,680 -0.1% T18282(normal) ghc/alloc 128,303,182 128,225,384 -0.1% T18304(normal) ghc/alloc 84,904,713 84,831,952 -0.1% T18923(normal) ghc/alloc 66,817,241 66,731,984 -0.1% T20049(normal) ghc/alloc 86,188,024 86,107,920 -0.1% T5837(normal) ghc/alloc 35,540,598 35,464,568 -0.2% T6048(optasm) ghc/alloc 99,812,171 99,736,032 -0.1% T9198(normal) ghc/alloc 46,380,270 46,304,984 -0.2% geo. mean -0.0% Metric Increase: T3064
* Cleanup tests in directory ghci.debugger. Fixes #21009Roland Senn2022-01-2610-12/+11
| | | | | | | | | * Remove wrong comment about panic in `break003.script`. * Improve test `break008`. * Add test `break028` to `all.T` * Fix wrong comments in `print019.script`, `print026.script` and `result001.script`. * Remove wrong comments from `print024.script` and `print031.script`. * Replace old module name with current name in `print035.script`.
* RTTI: Substitute the [rk] skolems into kindsMatthew Pickering2022-01-117-0/+43
| | | | | | (Fixes #10616 and #10617) Co-authored-by: Roland Senn <rsx@bluewin.ch>
* Add regressiontest for #18045Roland Senn2022-01-034-0/+49
| | | | Issue #18045 got fixed by !6971.
* Use HasCallStack and error in GHC.List and .NonEmptyOleg Grenrus2021-12-122-2/+7
| | | | | | | | | | | | | | | | | In addition to providing stack traces, the scary HasCallStack will hopefully make people think whether they want to use these functions, i.e. act as a documentation hint that something weird might happen. A single metric increased, which doesn't visibly use any method with `HasCallStack`. ------------------------- Metric Decrease: T9630 Metric Decrease: T19695 T9630 -------------------------
* Remove `optLevel` from `DynFlags` (closes #20500)Gergo ERDI2021-12-091-1/+1
|
* GHCi Debugger - Improve RTTIRoland Senn2021-11-252-10/+10
| | | | | | | When processing the heap, use also `APClosures` to create additional type constraints. This adds more equations and therefore improves the unification process to infer the correct type of values at breakpoints. (Fix the `incr` part of #19559)
* Combine STG free variable traversals (#17978)nineonine2021-11-232-10/+9
| | | | | | | | | | | | | | | | | | | | | Previously we would traverse the STG AST twice looking for free variables. * Once in `annTopBindingsDeps` which considers top level and imported ids free. Its output is used to put bindings in dependency order. The pass happens in STG pipeline. * Once in `annTopBindingsFreeVars` which only considers non-top level ids free. Its output is used by the code generator to compute offsets into closures. This happens in Cmm (CodeGen) pipeline. Now these two traversal operations are merged into one - `FVs.depSortWithAnnotStgPgm`. The pass happens right at the end of STG pipeline. Some type signatures had to be updated due to slight shifts of StgPass boundaries (for example, top-level CodeGen handler now directly works with CodeGen flavoured Stg AST instead of Vanilla). Due to changed order of bindings, a few debugger type reconstruction bugs have resurfaced again (see tests break018, break021) - work item #18004 tracks this investigation. authors: simonpj, nineonine
* Include "not more specific" info in overlap msgsheaf2021-11-202-12/+9
| | | | | | | | | When instances overlap, we now include additional information about why we weren't able to select an instance: perhaps one instance overlapped another but was not strictly more specific, so we aren't able to directly choose it. Fixes #20542
* undefined: Neater CallStack in error messageJoachim Breitner2021-10-241-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | Users of `undefined` don’t want to see ``` files.hs: Prelude.undefined: CallStack (from HasCallStack): error, called at libraries/base/GHC/Err.hs:79:14 in base:GHC.Err undefined, called at file.hs:151:19 in main:Main ``` but want to see ``` files.hs: Prelude.undefined: CallStack (from HasCallStack): undefined, called at file.hs:151:19 in main:Main ``` so let’s make that so. The function for that is `withFrozenCallStack`, but that is not usable here (module dependencies, and also not representation-polymorphic). And even if it were, it could confuse GHC’s strictness analyzer, leading to big regressions in some perf tests (T10421 in particular). So after shuffling modules and definitions around, I eventually noticed that the easiest way is to just not call `error` here. Fixes #19886
* Improve overlap error for polykinded constraintssheaf2021-10-062-6/+6
| | | | | | | | | | | | | | There were two problems around `mkDictErr`: 1. An outdated call to `flattenTys` meant that we missed out on some instances. As we no longer flatten type-family applications, the logic is obsolete and can be removed. 2. We reported "out of scope" errors in a poly-kinded situation because `BoxedRep` and `Lifted` were considered out of scope. We fix this by using `pretendNameIsInScope`. fixes #20465
* Remove redundant test case print036.Roland Senn2021-07-013-4/+0
| | | | | | The test case `print036` was marked `broken` by #9046. Issue #9046 is a duplicate of #12449. However the test case `T12449` contains several test that are similar to those in `print036`. Hence test case `print036` is redundant and can be deleted.
* Driver Rework PatchMatthew Pickering2021-06-034-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch comprises of four different but closely related ideas. The net result is fixing a large number of open issues with the driver whilst making it simpler to understand. 1. Use the hash of the source file to determine whether the source file has changed or not. This makes the recompilation checking more robust to modern build systems which are liable to copy files around changing their modification times. 2. Remove the concept of a "stable module", a stable module was one where the object file was older than the source file, and all transitive dependencies were also stable. Now we don't rely on the modification time of the source file, the notion of stability is moot. 3. Fix TH/plugin recompilation after the removal of stable modules. The TH recompilation check used to rely on stable modules. Now there is a uniform and simple way, we directly track the linkables which were loaded into the interpreter whilst compiling a module. This is an over-approximation but more robust wrt package dependencies changing. 4. Fix recompilation checking for dynamic object files. Now we actually check if the dynamic object file exists when compiling with -dynamic-too Fixes #19774 #19771 #19758 #17434 #11556 #9121 #8211 #16495 #7277 #16093
* Allow primops in a :print (and friends) command. Fix #19394Roland Senn2021-06-023-0/+16
| | | | | | | * For primops from `GHC.Prim` lookup the HValues in `GHC.PrimopWrappers`. * Add short error messages if a user tries to use a *Non-Id* value or a `pseudoop` in a `:print`, `:sprint` or `force`command. * Add additional test cases for `Magic Ids`.
* Use pprSigmaType to print GHCi debugger Suspension Terms (Fix #19355)Roland Senn2021-05-206-8/+23
| | | | | | | | In the GHCi debugger use the function `pprSigmaType` to print out Suspension Terms. The function `pprSigmaType` respect the flag `-f(no-)print-explicit-foralls` and so it fixes #19355. Switch back output of existing tests to default mode (no explicit foralls).
* Tweak function `quantifyType` to fix #12449Roland Senn2021-05-047-9/+56
| | | | | | | | | | | In function `compiler/GHC/Runtime/Heap/Inspect.hs:quantifyType` replace `tcSplitForAllInvisTyVars` by `tcSplitNestedSigmaTys`. This will properly split off the nested foralls in examples like `:print fmap`. Do not remove the `forall`s from the `snd` part of the tuple returned by `quantifyType`. It's not necessary and the reason for the bug in #12449. Some code simplifications at the calling sites of `quantifyTypes`.
* Always generate ModDetails from ModIfaceMatthew Pickering2021-04-141-2/+2
| | | | | | | | | | | | | | | | | | This vastly reduces memory usage when compiling with `--make` mode, from about 900M when compiling Cabal to about 300M. As a matter of uniformity, it also ensures that reading from an interface performs the same as using the in-memory cache. We can also delete all the horrible knot-tying in updateIdInfos. Goes some way to fixing #13586 Accept new output of tests fixing some bugs along the way ------------------------- Metric Decrease: T12545 -------------------------
* Ignore breakpoint for a specified number of iterations. (#19157)Roland Senn2021-03-104-0/+70
| | | | | | | | | | | | | | | | * Implement new debugger command `:ignore` to set an `ignore count` for a specified breakpoint. * Allow new optional parameter on `:continue` command to set an `ignore count` for the current breakpoint. * In the Interpreter replace the current `Word8` BreakArray with an `Int` array. * Change semantics of values in `BreakArray` to: n < 0 : Breakpoint is disabled. n == 0 : Breakpoint is enabled. n > 0 : Breakpoint is enabled, but ignore next `n` iterations. * Rewrite `:enable`/`:disable` processing as a special case of `:ignore`. * Remove references to `BreakArray` from `ghc/UI.hs`.
* Unify result type earlier to improve error messagesSimon Peyton Jones2021-03-011-5/+5
| | | | | | | | | | | | | | | | | | | | | | Ticket #19364 helpfully points out that we do not currently take advantage of pushing the result type of an application into the arguments. This makes error messages notably less good. The fix is rather easy: move the result-type unification step earlier. It's even a bit more efficient; in the the checking case we now do one less zonk. See Note [Unify with expected type before typechecking arguments] in GHC.Tc.Gen.App This change generally improves error messages, but it made one worse: typecheck/should_fail/T16204c. That led me to the realisation that a good error can be replaced by a less-good one, which provoked me to change GHC.Tc.Solver.Interact.inertsCanDischarge. It's explained in the new Note [Combining equalities] One other refactoring: I discovered that KindEqOrigin didn't need a Maybe in its type -- a nice simplification.
* Improve handling of overloaded labels, literals, lists etcwip/T19154Simon Peyton Jones2021-02-193-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When implementing Quick Look I'd failed to remember that overloaded labels, like #foo, should be treated as a "head", so that they can be instantiated with Visible Type Application. This caused #19154. A very similar ticket covers overloaded literals: #19167. This patch fixes both problems, but (annoyingly, albeit temporarily) in two different ways. Overloaded labels I dealt with overloaded labels by buying fully into the Rebindable Syntax approach described in GHC.Hs.Expr Note [Rebindable syntax and HsExpansion]. There is a good overview in GHC.Rename.Expr Note [Handling overloaded and rebindable constructs]. That module contains much of the payload for this patch. Specifically: * Overloaded labels are expanded in the renamer, fixing #19154. See Note [Overloaded labels] in GHC.Rename.Expr. * Left and right sections used to have special code paths in the typechecker and desugarer. Now we just expand them in the renamer. This is harder than it sounds. See GHC.Rename.Expr Note [Left and right sections]. * Infix operator applications are expanded in the typechecker, specifically in GHC.Tc.Gen.App.splitHsApps. See Note [Desugar OpApp in the typechecker] in that module * ExplicitLists are expanded in the renamer, when (and only when) OverloadedLists is on. * HsIf is expanded in the renamer when (and only when) RebindableSyntax is on. Reason: the coverage checker treats HsIf specially. Maybe we could instead expand it unconditionally, and fix up the coverage checker, but I did not attempt that. Overloaded literals Overloaded literals, like numbers (3, 4.2) and strings with OverloadedStrings, were not working correctly with explicit type applications (see #19167). Ideally I'd also expand them in the renamer, like the stuff above, but I drew back on that because they can occur in HsPat as well, and I did not want to to do the HsExpanded thing for patterns. But they *can* now be the "head" of an application in the typechecker, and hence something like ("foo" @T) works now. See GHC.Tc.Gen.Head.tcInferOverLit. It's also done a bit more elegantly, rather than by constructing a new HsExpr and re-invoking the typechecker. There is some refactoring around tcShortCutLit. Ultimately there is more to do here, following the Rebindable Syntax story. There are a lot of knock-on effects: * HsOverLabel and ExplicitList no longer need funny (Maybe SyntaxExpr) fields to support rebindable syntax -- good! * HsOverLabel, OpApp, SectionL, SectionR all become impossible in the output of the typecheker, GhcTc; so we set their extension fields to Void. See GHC.Hs.Expr Note [Constructor cannot occur] * Template Haskell quotes for HsExpanded is a bit tricky. See Note [Quotation and rebindable syntax] in GHC.HsToCore.Quote. * In GHC.HsToCore.Match.viewLExprEq, which groups equal HsExprs for the purpose of pattern-match overlap checking, I found that dictionary evidence for the same type could have two different names. Easily fixed by comparing types not names. * I did quite a bit of annoying fiddling around in GHC.Tc.Gen.Head and GHC.Tc.Gen.App to get error message locations and contexts right, esp in splitHsApps, and the HsExprArg type. Tiresome and not very illuminating. But at least the tricky, higher order, Rebuilder function is gone. * Some refactoring in GHC.Tc.Utils.Monad around contexts and locations for rebindable syntax. * Incidentally fixes #19346, because we now print renamed, rather than typechecked, syntax in error mesages about applications. The commit removes the vestigial module GHC.Builtin.RebindableNames, and thus triggers a 2.4% metric decrease for test MultiLayerModules (#19293). Metric Decrease: MultiLayerModules T12545
* Add instances for GHC.Tuple.SoloBen Gamari2021-01-272-3/+3
| | | | | | | | | | | | | | | The `Applicative` instance is the most important one (for array/vector/sequence indexing purposes), but it deserves all the usual ones. T12545 does silly 1% wibbles both ways, it seems, maybe depending on architecture. Metric Increase: T12545 Metric Decrease: T12545
* Kill floatEqualities completelySimon Peyton Jones2020-12-201-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch delivers on #17656, by entirel killing off the complex floatEqualities mechanism. Previously, floatEqualities would float an equality out of an implication, so that it could be solved at an outer level. But now we simply do unification in-place, without floating the constraint, relying on level numbers to determine untouchability. There are a number of important new Notes: * GHC.Tc.Utils.Unify Note [Unification preconditions] describes the preconditions for unification, including both skolem-escape and touchability. * GHC.Tc.Solver.Interact Note [Solve by unification] describes what we do when we do unify * GHC.Tc.Solver.Monad Note [The Unification Level Flag] describes how we control solver iteration under this new scheme * GHC.Tc.Solver.Monad Note [Tracking Given equalities] describes how we track when we have Given equalities * GHC.Tc.Types.Constraint Note [HasGivenEqs] is a new explanation of the ic_given_eqs field of an implication A big raft of subtle Notes in Solver, concerning floatEqualities, disappears. Main code changes: * GHC.Tc.Solver.floatEqualities disappears entirely * GHC.Tc.Solver.Monad: new fields in InertCans, inert_given_eq_lvl and inert_given_eq, updated by updateGivenEqs See Note [Tracking Given equalities]. * In exchange for updateGivenEqa, GHC.Tc.Solver.Monad.getHasGivenEqs is much simpler and more efficient * I found I could kill of metaTyVarUpdateOK entirely One test case T14683 showed a 5.1% decrease in compile-time allocation; and T5631 was down 2.2%. Other changes were small. Metric Decrease: T14683 T5631
* Improve kind generalisation, error messagesSimon Peyton Jones2020-09-241-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does two things: * It refactors GHC.Tc.Errors a bit. In debugging Quick Look I was forced to look in detail at error messages, and ended up doing a bit of refactoring, esp in mkTyVarEqErr'. It's still quite a mess, but a bit better, I think. * It makes a significant improvement to the kind checking of type and class declarations. Specifically, we now ensure that if kind checking fails with an unsolved constraint, all the skolems are in scope. That wasn't the case before, which led to some obscure error messages; and occasional failures with "no skolem info" (eg #16245). Both of these, and the main Quick Look patch itself, affect a /lot/ of error messages, as you can see from the number of files changed. I've checked them all; I think they are as good or better than before. Smaller things * I documented the various instances of VarBndr better. See Note [The VarBndr tyep and its uses] in GHC.Types.Var * Renamed GHC.Tc.Solver.simpl_top to simplifyTopWanteds * A bit of refactoring in bindExplicitTKTele, to avoid the footwork with Either. Simpler now. * Move promoteTyVar from GHC.Tc.Solver to GHC.Tc.Utils.TcMType Fixes #16245 (comment 211369), memorialised as typecheck/polykinds/T16245a Also fixes the three bugs in #18640
* Fix GHCi :print on big-endian platformsStefan Schulze Frielinghaus2020-07-091-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On big-endian platforms executing import GHC.Exts data Foo = Foo Float# deriving Show foo = Foo 42.0# foo :print foo results in an arithmetic overflow exception which is caused by function index where moveBytes equals word_size - (r + item_size_b) * 8 Here we have a mixture of units. Both, word_size and item_size_b have unit bytes whereas r has unit bits. On 64-bit platforms moveBytes equals then 8 - (0 + 4) * 8 which results in a negative and therefore invalid second parameter for a shiftL operation. In order to make things more clear the expression (word .&. (mask `shiftL` moveBytes)) `shiftR` moveBytes is equivalent to (word `shiftR` moveBytes) .&. mask On big-endian platforms the shift must be a left shift instead of a right shift. For symmetry reasons not a mask is used but two shifts in order to zero out bits. Thus the fixed version equals case endian of BigEndian -> (word `shiftL` moveBits) `shiftR` zeroOutBits `shiftL` zeroOutBits LittleEndian -> (word `shiftR` moveBits) `shiftL` zeroOutBits `shiftR` zeroOutBits Fixes #16548 and #14455
* In `:break ident` allow out of scope and nested identifiers (Fix #3000)Roland Senn2020-06-259-6/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the bug and implements the feature request of #3000. 1. If `Module` is a real module name and `identifier` a name of a top-level function in `Module` then `:break Module.identifer` works also for an `identifier` that is out of scope. 2. Extend the syntax for `:break identifier` to: :break [ModQual.]topLevelIdent[.nestedIdent]...[.nestedIdent] `ModQual` is optional and is either the effective name of a module or the local alias of a qualified import statement. `topLevelIdent` is the name of a top level function in the module referenced by `ModQual`. `nestedIdent` is optional and the name of a function nested in a let or where clause inside the previously mentioned function `nestedIdent` or `topLevelIdent`. If `ModQual` is a module name, then `topLevelIdent` can be any top level identifier in this module. If `ModQual` is missing or a local alias of a qualified import, then `topLevelIdent` must be in scope. Breakpoints can be set on arbitrarily deeply nested functions, but the whole chain of nested function names must be specified. 3. To support the new functionality rewrite the code to tab complete `:break`.
* Update testsuiteSylvain Henry2020-06-175-17/+11
| | | | | | | | | | | | | | * support detection of slow ghc-bignum backend (to replace the detection of integer-simple use). There are still some test cases that the native backend doesn't handle efficiently enough. * remove tests for GMP only functions that have been removed from ghc-bignum * fix test results showing dependent packages (e.g. integer-gmp) or showing suggested instances * fix test using Integer/Natural API or showing internal names
* Linear types (#15981)Krzysztof Gogolewski2020-06-173-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the first step towards implementation of the linear types proposal (https://github.com/ghc-proposals/ghc-proposals/pull/111). It features * A language extension -XLinearTypes * Syntax for linear functions in the surface language * Linearity checking in Core Lint, enabled with -dlinear-core-lint * Core-to-core passes are mostly compatible with linearity * Fields in a data type can be linear or unrestricted; linear fields have multiplicity-polymorphic constructors. If -XLinearTypes is disabled, the GADT syntax defaults to linear fields The following items are not yet supported: * a # m -> b syntax (only prefix FUN is supported for now) * Full multiplicity inference (multiplicities are really only checked) * Decent linearity error messages * Linear let, where, and case expressions in the surface language (each of these currently introduce the unrestricted variant) * Multiplicity-parametric fields * Syntax for annotating lambda-bound or let-bound with a multiplicity * Syntax for non-linear/multiple-field-multiplicity records * Linear projections for records with a single linear field * Linear pattern synonyms * Multiplicity coercions (test LinearPolyType) A high-level description can be found at https://ghc.haskell.org/trac/ghc/wiki/LinearTypes/Implementation Following the link above you will find a description of the changes made to Core. This commit has been authored by * Richard Eisenberg * Krzysztof Gogolewski * Matthew Pickering * Arnaud Spiwack With contributions from: * Mark Barbone * Alexander Vershilov Updates haddock submodule.
* Simple subsumptionwip/T17775Simon Peyton Jones2020-06-051-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch simplifies GHC to use simple subsumption. Ticket #17775 Implements GHC proposal #287 https://github.com/ghc-proposals/ghc-proposals/blob/master/ proposals/0287-simplify-subsumption.rst All the motivation is described there; I will not repeat it here. The implementation payload: * tcSubType and friends become noticably simpler, because it no longer uses eta-expansion when checking subsumption. * No deeplyInstantiate or deeplySkolemise That in turn means that some tests fail, by design; they can all be fixed by eta expansion. There is a list of such changes below. Implementing the patch led me into a variety of sticky corners, so the patch includes several othe changes, some quite significant: * I made String wired-in, so that "foo" :: String rather than "foo" :: [Char] This improves error messages, and fixes #15679 * The pattern match checker relies on knowing about in-scope equality constraints, andd adds them to the desugarer's environment using addTyCsDs. But the co_fn in a FunBind was missed, and for some reason simple-subsumption ends up with dictionaries there. So I added a call to addTyCsDs. This is really part of #18049. * I moved the ic_telescope field out of Implication and into ForAllSkol instead. This is a nice win; just expresses the code much better. * There was a bug in GHC.Tc.TyCl.Instance.tcDataFamInstHeader. We called checkDataKindSig inside tc_kind_sig, /before/ solveEqualities and zonking. Obviously wrong, easily fixed. * solveLocalEqualitiesX: there was a whole mess in here, around failing fast enough. I discovered a bad latent bug where we could successfully kind-check a type signature, and use it, but have unsolved constraints that could fill in coercion holes in that signature -- aargh. It's all explained in Note [Failure in local type signatures] in GHC.Tc.Solver. Much better now. * I fixed a serious bug in anonymous type holes. IN f :: Int -> (forall a. a -> _) -> Int that "_" should be a unification variable at the /outer/ level; it cannot be instantiated to 'a'. This was plain wrong. New fields mode_lvl and mode_holes in TcTyMode, and auxiliary data type GHC.Tc.Gen.HsType.HoleMode. This fixes #16292, but makes no progress towards the more ambitious #16082 * I got sucked into an enormous refactoring of the reporting of equality errors in GHC.Tc.Errors, especially in mkEqErr1 mkTyVarEqErr misMatchMsg misMatchMsgOrCND In particular, the very tricky mkExpectedActualMsg function is gone. It took me a full day. But the result is far easier to understand. (Still not easy!) This led to various minor improvements in error output, and an enormous number of test-case error wibbles. One particular point: for occurs-check errors I now just say Can't match 'a' against '[a]' rather than using the intimidating language of "occurs check". * Pretty-printing AbsBinds Tests review * Eta expansions T11305: one eta expansion T12082: one eta expansion (undefined) T13585a: one eta expansion T3102: one eta expansion T3692: two eta expansions (tricky) T2239: two eta expansions T16473: one eta determ004: two eta expansions (undefined) annfail06: two eta (undefined) T17923: four eta expansions (a strange program indeed!) tcrun035: one eta expansion * Ambiguity check at higher rank. Now that we have simple subsumption, a type like f :: (forall a. Eq a => Int) -> Int is no longer ambiguous, because we could write g :: (forall a. Eq a => Int) -> Int g = f and it'd typecheck just fine. But f's type is a bit suspicious, and we might want to consider making the ambiguity check do a check on each sub-term. Meanwhile, these tests are accepted, whereas they were previously rejected as ambiguous: T7220a T15438 T10503 T9222 * Some more interesting error message wibbles T13381: Fine: one error (Int ~ Exp Int) rather than two (Int ~ Exp Int, Exp Int ~ Int) T9834: Small change in error (improvement) T10619: Improved T2414: Small change, due to order of unification, fine T2534: A very simple case in which a change of unification order means we get tow unsolved constraints instead of one tc211: bizarre impredicative tests; just accept this for now Updates Cabal and haddock submodules. Metric Increase: T12150 T12234 T5837 haddock.base Metric Decrease: haddock.compiler haddock.Cabal haddock.base Merge note: This appears to break the `UnliftedNewtypesDifficultUnification` test. It has been marked as broken in the interest of merging. (cherry picked from commit 66b7b195cb3dce93ed5078b80bf568efae904cc5)
* Fix tab-completion for :break (#17989)Roland Senn2020-04-227-0/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In tab-completion for the `:break` command, only those identifiers should be shown, that are accepted in the `:break` command. Hence these identifiers must be - defined in an interpreted module - top-level - currently in scope - listed in a `ModBreaks` value as a possible breakpoint. The identifiers my be qualified or unqualified. To get all possible top-level breakpoints for tab-completeion with the correct qualification do: 1. Build the list called `pifsBreaks` of all pairs of (Identifier, module-filename) from the `ModBreaks` values. Here all identifiers are unqualified. 2. Build the list called `pifInscope` of all pairs of (Identifiers, module-filename) with identifiers from the `GlobalRdrEnv`. Take only those identifiers that are in scope and have the correct prefix. Here the identifiers may be qualified. 3. From the `pifInscope` list seclect all pairs that can be found in the `pifsBreaks` list, by comparing only the unqualified part of the identifier. The remaining identifiers can be used for tab-completion. This ensures, that we show only identifiers, that can be used in a `:break` command.
* simplifier: Kill off ufKeenessFactorBen Gamari2020-04-072-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We used to have another factor, ufKeenessFactor, which would scale the discounts before they were subtracted from the size. This was justified with the following comment: -- We multiple the raw discounts (args_discount and result_discount) -- ty opt_UnfoldingKeenessFactor because the former have to do with -- *size* whereas the discounts imply that there's some extra -- *efficiency* to be gained (e.g. beta reductions, case reductions) -- by inlining. However, this is highly suspect since it means that we subtract a *scaled* size from an absolute size, resulting in crazy (e.g. negative) scores in some cases (#15304). We consequently killed off ufKeenessFactor and bumped up the ufUseThreshold to compensate. Adjustment of unfolding use threshold ===================================== Since this removes a discount from our inlining heuristic, I revisited our default choice of -funfolding-use-threshold to minimize the change in overall inlining behavior. Specifically, I measured runtime allocations and executable size of nofib and the testsuite performance tests built using compilers (and core libraries) built with several values of -funfolding-use-threshold. This comes as a result of a quantitative comparison of testsuite performance and code size as a function of ufUseThreshold, comparing GHC trees using values of 50, 60, 70, 80, 90, and 100. The test set consisted of nofib and the testsuite performance tests. A full summary of these measurements are found in the description of !2608 Comparing executable sizes (relative to the base commit) across all nofib tests, we see that sizes are similar to the baseline: gmean min max median thresh 50 -6.36% -7.04% -4.82% -6.46% 60 -5.04% -5.97% -3.83% -5.11% 70 -2.90% -3.84% -2.31% -2.92% 80 -0.75% -2.16% -0.42% -0.73% 90 +0.24% -0.41% +0.55% +0.26% 100 +1.36% +0.80% +1.64% +1.37% baseline +0.00% +0.00% +0.00% +0.00% Likewise, looking at runtime allocations we see that 80 gives slightly better optimisation than the baseline: gmean min max median thresh 50 +0.16% -0.16% +4.43% +0.00% 60 +0.09% -0.00% +3.10% +0.00% 70 +0.04% -0.09% +2.29% +0.00% 80 +0.02% -1.17% +2.29% +0.00% 90 -0.02% -2.59% +1.86% +0.00% 100 +0.00% -2.59% +7.51% -0.00% baseline +0.00% +0.00% +0.00% +0.00% Finally, I had to add a NOINLINE in T4306 to ensure that `upd` is worker-wrappered as the test expects. This makes me wonder whether the inlining heuristic is now too liberal as `upd` is quite a large function. The same measure was taken in T12600. Wall clock time compiling Cabal with -O0 thresh 50 60 70 80 90 100 baseline build-Cabal 93.88 89.58 92.59 90.09 100.26 94.81 89.13 Also, this change happens to avoid the spurious test output in `plugin-recomp-change` and `plugin-recomp-change-prof` (see #17308). Metric Decrease: hie002 T12234 T13035 T13719 T14683 T4801 T5631 T5642 T9020 T9872d T9961 Metric Increase: T12150 T12425 T13701 T14697 T15426 T1969 T3064 T5837 T6048 T9203 T9872a T9872b T9872c T9872d haddock.Cabal haddock.base haddock.compiler
* Simplify treatment of heterogeneous equalityRichard Eisenberg2020-03-201-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Previously, if we had a [W] (a :: k1) ~ (rhs :: k2), we would spit out a [D] k1 ~ k2 and part the W as irreducible, hoping for a unification. But we needn't do this. Instead, we now spit out a [W] co :: k2 ~ k1 and then use co to cast the rhs of the original Wanted. This means that we retain the connection between the spat-out constraint and the original. The problem with this new approach is that we cannot use the casted equality for substitution; it's too like wanteds-rewriting- wanteds. So, we forbid CTyEqCans that mention coercion holes. All the details are in Note [Equalities with incompatible kinds] in TcCanonical. There are a few knock-on effects, documented where they occur. While debugging an error in this patch, Simon and I ran into infelicities in how patterns and matches are printed; we made small improvements. This patch includes mitigations for #17828, which causes spurious pattern-match warnings. When #17828 is fixed, these lines should be removed.
* Set `ImpredicativeTypes` during :print command. (#14828)Roland Senn2020-03-021-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If ImpredicativeTypes is not enabled, then `:print <term>` will fail if the type of <term> has nested `forall`s or `=>`s. This is because the GHCi debugger's internals will attempt to unify a metavariable with the type of <term> and then display the result, but if the type has nested `forall`s or `=>`s, then unification will fail. As a result, `:print` will bail out and the unhelpful result will be `<term> = (_t1::t1)` (where `t1` is a metavariable). Beware: <term> can have nested `forall`s even if its definition doesn't use RankNTypes! Here is an example from #14828: class Functor f where fmap :: (a -> b) -> f a -> f b Somewhat surprisingly, `:print fmap` considers the type of fmap to have nested foralls. This is because the GHCi debugger sees the type `fmap :: forall f. Functor f => forall a b. (a -> b) -> f a -> f b`. We could envision deeply instantiating this type to get the type `forall f a b. Functor f => (a -> b) -> f a -> f b`, but this trick wouldn't work for higher-rank types. Instead, we adopt a simpler fix: enable `ImpredicativeTypes` when using `:print` and friends in the GHCi debugger. This is allows metavariables to unify with types that have nested (or higher-rank) `forall`s/`=>`s, which makes `:print fmap` display as `fmap = (_t1::forall a b. Functor f => (a -> b) -> f a -> f b)`, as expected. Although ImpredicativeTypes is a somewhat unpredictable from a type inference perspective, there is no danger in using it in the GHCi debugger, since all of the terms that the GHCi debugger deals with have already been typechecked.
* Show breakpoint locations of breakpoints which were ignored during :force ↵Roland Senn2020-02-296-1/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (#2950) GHCi is split up into 2 major parts: The user-interface (UI) and the byte-code interpreter. With `-fexternal-interpreter` they even run in different processes. Communication between the UI and the Interpreter (called `iserv`) is done using messages over a pipe. This is called `Remote GHCI` and explained in the Note [Remote GHCi] in `compiler/ghci/GHCi.hs`. To process a `:force` command the UI sends a `Seq` message to the `iserv` process. Then `iserv` does the effective evaluation of the value. When during this process a breakpoint is hit, the `iserv` process has no additional information to enhance the `Ignoring breakpoint` output with the breakpoint location. To be able to print additional breakpoint information, there are 2 possible implementation choices: 1. Store the needed information in the `iserv` process. 2. Print the `Ignoring breakpoint` from the UI process. For option 1 we need to store the breakpoint info redundantely in 2 places and this is bad. Therfore option 2 was implemented in this MR: - The user enters a `force` command - The UI sends a `Seq` message to the `iserv` process. - If processing of the `Seq` message hits a breakpoint, the `iserv` process returns control to the UI process. - The UI looks up the source location of the breakpoint, and prints the enhanced `Ignoring breakpoint` output. - The UI sends a `ResumeSeq` message to the `iserv` process, to continue forcing.
* Re-implement unsafe coercions in terms of unsafe equality proofsSimon Peyton Jones2020-02-201-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (Commit message written by Omer, most of the code is written by Simon and Richard) See Note [Implementing unsafeCoerce] for how unsafe equality proofs and the new unsafeCoerce# are implemented. New notes added: - [Checking for levity polymorphism] in CoreLint.hs - [Implementing unsafeCoerce] in base/Unsafe/Coerce.hs - [Patching magic definitions] in Desugar.hs - [Wiring in unsafeCoerce#] in Desugar.hs Only breaking change in this patch is unsafeCoerce# is not exported from GHC.Exts, instead of GHC.Prim. Fixes #17443 Fixes #16893 NoFib ----- -------------------------------------------------------------------------------- Program Size Allocs Instrs Reads Writes -------------------------------------------------------------------------------- CS -0.1% 0.0% -0.0% -0.0% -0.0% CSD -0.1% 0.0% -0.0% -0.0% -0.0% FS -0.1% 0.0% -0.0% -0.0% -0.0% S -0.1% 0.0% -0.0% -0.0% -0.0% VS -0.1% 0.0% -0.0% -0.0% -0.0% VSD -0.1% 0.0% -0.0% -0.0% -0.1% VSM -0.1% 0.0% -0.0% -0.0% -0.0% anna -0.0% 0.0% -0.0% -0.0% -0.0% ansi -0.1% 0.0% -0.0% -0.0% -0.0% atom -0.1% 0.0% -0.0% -0.0% -0.0% awards -0.1% 0.0% -0.0% -0.0% -0.0% banner -0.1% 0.0% -0.0% -0.0% -0.0% bernouilli -0.1% 0.0% -0.0% -0.0% -0.0% binary-trees -0.1% 0.0% -0.0% -0.0% -0.0% boyer -0.1% 0.0% -0.0% -0.0% -0.0% boyer2 -0.1% 0.0% -0.0% -0.0% -0.0% bspt -0.1% 0.0% -0.0% -0.0% -0.0% cacheprof -0.1% 0.0% -0.0% -0.0% -0.0% calendar -0.1% 0.0% -0.0% -0.0% -0.0% cichelli -0.1% 0.0% -0.0% -0.0% -0.0% circsim -0.1% 0.0% -0.0% -0.0% -0.0% clausify -0.1% 0.0% -0.0% -0.0% -0.0% comp_lab_zift -0.1% 0.0% -0.0% -0.0% -0.0% compress -0.1% 0.0% -0.0% -0.0% -0.0% compress2 -0.1% 0.0% -0.0% -0.0% -0.0% constraints -0.1% 0.0% -0.0% -0.0% -0.0% cryptarithm1 -0.1% 0.0% -0.0% -0.0% -0.0% cryptarithm2 -0.1% 0.0% -0.0% -0.0% -0.0% cse -0.1% 0.0% -0.0% -0.0% -0.0% digits-of-e1 -0.1% 0.0% -0.0% -0.0% -0.0% digits-of-e2 -0.1% 0.0% -0.0% -0.0% -0.0% dom-lt -0.1% 0.0% -0.0% -0.0% -0.0% eliza -0.1% 0.0% -0.0% -0.0% -0.0% event -0.1% 0.0% -0.0% -0.0% -0.0% exact-reals -0.1% 0.0% -0.0% -0.0% -0.0% exp3_8 -0.1% 0.0% -0.0% -0.0% -0.0% expert -0.1% 0.0% -0.0% -0.0% -0.0% fannkuch-redux -0.1% 0.0% -0.0% -0.0% -0.0% fasta -0.1% 0.0% -0.5% -0.3% -0.4% fem -0.1% 0.0% -0.0% -0.0% -0.0% fft -0.1% 0.0% -0.0% -0.0% -0.0% fft2 -0.1% 0.0% -0.0% -0.0% -0.0% fibheaps -0.1% 0.0% -0.0% -0.0% -0.0% fish -0.1% 0.0% -0.0% -0.0% -0.0% fluid -0.1% 0.0% -0.0% -0.0% -0.0% fulsom -0.1% 0.0% +0.0% +0.0% +0.0% gamteb -0.1% 0.0% -0.0% -0.0% -0.0% gcd -0.1% 0.0% -0.0% -0.0% -0.0% gen_regexps -0.1% 0.0% -0.0% -0.0% -0.0% genfft -0.1% 0.0% -0.0% -0.0% -0.0% gg -0.1% 0.0% -0.0% -0.0% -0.0% grep -0.1% 0.0% -0.0% -0.0% -0.0% hidden -0.1% 0.0% -0.0% -0.0% -0.0% hpg -0.1% 0.0% -0.0% -0.0% -0.0% ida -0.1% 0.0% -0.0% -0.0% -0.0% infer -0.1% 0.0% -0.0% -0.0% -0.0% integer -0.1% 0.0% -0.0% -0.0% -0.0% integrate -0.1% 0.0% -0.0% -0.0% -0.0% k-nucleotide -0.1% 0.0% -0.0% -0.0% -0.0% kahan -0.1% 0.0% -0.0% -0.0% -0.0% knights -0.1% 0.0% -0.0% -0.0% -0.0% lambda -0.1% 0.0% -0.0% -0.0% -0.0% last-piece -0.1% 0.0% -0.0% -0.0% -0.0% lcss -0.1% 0.0% -0.0% -0.0% -0.0% life -0.1% 0.0% -0.0% -0.0% -0.0% lift -0.1% 0.0% -0.0% -0.0% -0.0% linear -0.1% 0.0% -0.0% -0.0% -0.0% listcompr -0.1% 0.0% -0.0% -0.0% -0.0% listcopy -0.1% 0.0% -0.0% -0.0% -0.0% maillist -0.1% 0.0% -0.0% -0.0% -0.0% mandel -0.1% 0.0% -0.0% -0.0% -0.0% mandel2 -0.1% 0.0% -0.0% -0.0% -0.0% mate -0.1% 0.0% -0.0% -0.0% -0.0% minimax -0.1% 0.0% -0.0% -0.0% -0.0% mkhprog -0.1% 0.0% -0.0% -0.0% -0.0% multiplier -0.1% 0.0% -0.0% -0.0% -0.0% n-body -0.1% 0.0% -0.0% -0.0% -0.0% nucleic2 -0.1% 0.0% -0.0% -0.0% -0.0% para -0.1% 0.0% -0.0% -0.0% -0.0% paraffins -0.1% 0.0% -0.0% -0.0% -0.0% parser -0.1% 0.0% -0.0% -0.0% -0.0% parstof -0.1% 0.0% -0.0% -0.0% -0.0% pic -0.1% 0.0% -0.0% -0.0% -0.0% pidigits -0.1% 0.0% -0.0% -0.0% -0.0% power -0.1% 0.0% -0.0% -0.0% -0.0% pretty -0.1% 0.0% -0.1% -0.1% -0.1% primes -0.1% 0.0% -0.0% -0.0% -0.0% primetest -0.1% 0.0% -0.0% -0.0% -0.0% prolog -0.1% 0.0% -0.0% -0.0% -0.0% puzzle -0.1% 0.0% -0.0% -0.0% -0.0% queens -0.1% 0.0% -0.0% -0.0% -0.0% reptile -0.1% 0.0% -0.0% -0.0% -0.0% reverse-complem -0.1% 0.0% -0.0% -0.0% -0.0% rewrite -0.1% 0.0% -0.0% -0.0% -0.0% rfib -0.1% 0.0% -0.0% -0.0% -0.0% rsa -0.1% 0.0% -0.0% -0.0% -0.0% scc -0.1% 0.0% -0.1% -0.1% -0.1% sched -0.1% 0.0% -0.0% -0.0% -0.0% scs -0.1% 0.0% -0.0% -0.0% -0.0% simple -0.1% 0.0% -0.0% -0.0% -0.0% solid -0.1% 0.0% -0.0% -0.0% -0.0% sorting -0.1% 0.0% -0.0% -0.0% -0.0% spectral-norm -0.1% 0.0% -0.0% -0.0% -0.0% sphere -0.1% 0.0% -0.0% -0.0% -0.0% symalg -0.1% 0.0% -0.0% -0.0% -0.0% tak -0.1% 0.0% -0.0% -0.0% -0.0% transform -0.1% 0.0% -0.0% -0.0% -0.0% treejoin -0.1% 0.0% -0.0% -0.0% -0.0% typecheck -0.1% 0.0% -0.0% -0.0% -0.0% veritas -0.0% 0.0% -0.0% -0.0% -0.0% wang -0.1% 0.0% -0.0% -0.0% -0.0% wave4main -0.1% 0.0% -0.0% -0.0% -0.0% wheel-sieve1 -0.1% 0.0% -0.0% -0.0% -0.0% wheel-sieve2 -0.1% 0.0% -0.0% -0.0% -0.0% x2n1 -0.1% 0.0% -0.0% -0.0% -0.0% -------------------------------------------------------------------------------- Min -0.1% 0.0% -0.5% -0.3% -0.4% Max -0.0% 0.0% +0.0% +0.0% +0.0% Geometric Mean -0.1% -0.0% -0.0% -0.0% -0.0% Test changes ------------ - break006 is marked as broken, see #17833 - The compiler allocates less when building T14683 (an unsafeCoerce#- heavy happy-generated code) on 64-platforms. Allocates more on 32-bit platforms. - Rest of the increases are tiny amounts (still enough to pass the threshold) in micro-benchmarks. I briefly looked at each one in a profiling build: most of the increased allocations seem to be because of random changes in the generated code. Metric Decrease: T14683 Metric Increase: T12150 T12234 T12425 T13035 T14683 T5837 T6048 Co-Authored-By: Richard Eisenberg <rae@cs.brynmawr.edu> Co-Authored-By: Ömer Sinan Ağacan <omeragacan@gmail.com>
* Fix #14628: Panic (No skolem Info) in GHCiRoland Senn2020-02-095-0/+36
| | | | | | | | | | | | | | This patch implements the [sugggestion from Simon (PJ)](https://gitlab.haskell.org/ghc/ghc/issues/14628#note_146559): - Make `TcErrors.getSkolemInfo` return a `SkolemInfo` rather than an `Implication`. - If `getSkolemInfo` gets `RuntimeUnk`s, just return a new data constructor in `SkolemInfo`, called `RuntimeUnkSkol`. - In `TcErrors.pprSkols` print something sensible for a `RuntimeUnkSkol`. The `getSkolemInfo` function paniced while formating suggestions to add type annotations (subfunction `suggestAddSig`) to a *"Couldn't match type ‘x’ with ‘y’"* error message. The `getSkolemInfo` function didn't find any Implication value and paniced. With this patch the `getSkolemInfo` function does no longer panic, if it finds `RuntimeUnkSkol`s. As the panic occured while processing an error message, we don't need to implement any new error message!
* testsuite: Mark print002 as fragile on ARMBen Gamari2019-12-171-1/+1
| | | | | | | | | Due to #17557. Also accepting spurious performance change. Metric Decrease: T1969
* testsuite: Mark T13825-debugger as broken on ARMv7Ben Gamari2019-12-171-1/+3
| | | | Due to #17557.
* Fix #14690 - :steplocal panics after break-on-errorRoland Senn2019-10-264-0/+19
| | | | | | | | | | | | | | `:steplocal` enables only breakpoints in the current top-level binding. When a normal breakpoint is hit, then the module name and the break id from the `BRK_FUN` byte code allow us to access the corresponding entry in a ModBreak table. From this entry we then get the SrcSpan (see compiler/main/InteractiveEval.hs:bindLocalsAtBreakpoint). With this source-span we can then determine the current top-level binding, needed for the steplocal command. However, if we break at an exception or at an error, we don't have an BRK_FUN byte-code, so we don't have any source information. The function `bindLocalsAtBreakpoint` creates an `UnhelpfulSpan`, which doesn't allow us to determine the current top-level binding. To avoid a `panic`, we have to check for `UnhelpfulSpan` in the function `ghc/GHCi/UI.hs:stepLocalCmd`. Hence a :steplocal command after a break-on-exception or a break-on-error is not possible.
* testsuite: Mark print037 as fragile, not brokenBen Gamari2019-10-031-2/+2
| | | | See #16205.
* Fix #8487: Debugger confuses variablesRoland Senn2019-07-214-0/+19
| | | | | | | | | | To display the free variables for a single breakpoint, GHCi pulls out the information from the fields `modBreaks_breakInfo` and `modBreaks_vars` of the `ModBreaks` data structure. For a specific breakpoint this gives 2 lists of types 'Id` (`Var`) and `OccName`. They are used to create the Id's for the free variables and must be kept in sync: If we remove an element from the Names list, then we also must remove the corresponding element from the OccNames list.
* ghci: Don't rely on resolution of System.IO to base moduleBen Gamari2019-06-224-5/+5
| | | | | | | | | Previously we would hackily evaluate a textual code snippet to compute actions to disable I/O buffering and flush the stdout/stderr handles. This broke in a number of ways (#15336, #16563). Instead we now ship a module (`GHC.GHCi.Helpers`) with `base` containing the needed actions. We can then easily refer to these via `Orig` names.
* Fix #1620: ModBreaks.modBreaks_array not initialisedRoland Senn2019-06-194-0/+34
| | | | | | | | | After a :cd command and after setting some package flags, GHCi unloads all loaded modules by resetting the list of targets. This patch deletes eventually defined debugger breakpoints, before GHCi resets the target list. The common code is factored out into the new function clearAllTargets.
* Add disable/enable commands to ghci debugger #2215Roland Senn2019-06-094-0/+72
| | | | | | | | | | | | | | | | | | | | This patch adds two new commands `:enable` and `:disable` to the GHCi debugger. Opposite to `:set stop <n> :continue` a breakpoint disabled with `:disable` will not loose its previously set stop command. A new field breakEnabled is added to the BreakLocation data structure to track the enable/disable state. When a breakpoint is disabled with a `:disable` command, the following happens: The corresponding BreakLocation data element is searched dictionary of the `breaks` field of the GHCiStateMonad. If the break point is found and not already in the disabled state, the breakpoint is removed from bytecode. The BreakLocation data structure is kept in the breaks list and the new breakEnabled field is set to false. The `:enable` command works similar. The breaks field in the GHCiStateMonad was changed from an association list to int `IntMap`.
* Fix #16700: Tiny errors in output of GHCi commands :forward and :infoRoland Senn2019-06-074-0/+18
| | | | | | `:info Coercible` now outputs the correct section number of the GHCi User's guide together with the secion title. `:forward x` gives the correct syntax hint.
* Reject nested predicates in impredicativity checkingRyan Scott2019-03-201-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | When GHC attempts to unify a metavariable with a type containing foralls, it will be rejected as an occurrence of impredicativity. GHC was /not/ extending the same treatment to predicate types, such as in the following (erroneous) example from #11514: ```haskell foo :: forall a. (Show a => a -> a) -> () foo = undefined ``` This will attempt to instantiate `undefined` at `(Show a => a -> a) -> ()`, which is impredicative. This patch catches impredicativity arising from predicates in this fashion. Since GHC is pickier about impredicative instantiations, some test cases needed to be updated to be updated so as not to fall afoul of the new validity check. (There were a surprising number of impredicative uses of `undefined`!) Moreover, the `T14828` test case now has slightly less informative types shown with `:print`. This is due to a a much deeper issue with the GHCi debugger (see #14828). Fixes #11514.
* testsuite: Mark print037 as broken when GHC is built with LLVMBen Gamari2019-02-041-1/+4
| | | | As noted in #16205 this configuration reliably segfaults.
* Fix tests for `integer-simple`Alec Theriault2019-01-1627-126/+131
| | | | | | | | | | | | A bunch of tests for `integer-simple` were now broken for a foolish reason: unlike the `integer-gmp` case, there is no CorePrep optimization for turning small integers directly into applications of `S#`. Rather than port this optimization to `integer-simple` (which would involve moving a bunch of `integer-simple` names into `PrelNames`), I switched as many tests as possible to use `Int`. The printing of `Integer` is already tested in `print037`.
* Support printing `integer-simple` Integers in GHCiAlec Theriault2019-01-163-0/+31
| | | | | | | | | | This means that `:p` no longer leaks the implementation details of `Integer` with `integer-simple`. The `print037` test case should exercise all possible code paths for GHCi's code around printing `Integer`s (both in `integer-simple` and `integer-gmp`). `ghc` the package now also has a Cabal `integer-simple` flag (like the `integer-gmp` one).
* testsuite: Fix a number of GHCi-related failures due to integer-simpleBen Gamari2018-12-121-26/+27
| | | | Towards fixing #16043.