sheaf authored 2 years ago and Marge Bot committed 2 years ago

The testsuite output now contains diagnostic codes, so many tests need
to be updated at once.
We decided it was best to keep the diagnostic codes in the testsuite
output, so that contributors don't inadvertently make changes to the
diagnostic codes.

Soham Chowdhury authored 2 years ago and Marge Bot committed 2 years ago

This patch improves the uniformity of error message formatting by
printing constraints in quotes, as we do for types.

Fix #21167

it is still re-exported from GHC.Exts

Matthew Pickering authored 3 years ago and Marge Bot committed 3 years ago

This reverts commit bddecda1.

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.

sheaf authored 3 years ago and Marge Bot committed 3 years ago

  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

sheaf authored 3 years ago and Marge Bot committed 3 years ago

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 An outdated call to `flattenTys` meant that we missed out on some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     the logic is obsolete and can be removed.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

sheaf authored 3 years ago and Marge Bot committed 3 years ago

Fixes #14380, #19997

Oleg Grenrus authored 4 years ago and Marge Bot committed 3 years ago

- Remove GHC.OldList
- Remove Data.OldList
- compat-unqualified-imports is no-op
- update haddock submodule

Ben Gamari authored 4 years ago and Marge Bot committed 4 years ago

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

* 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

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 66b7b195)

Add support for built-in Natural literals in Core.

- Replace MachInt,MachWord, LitInteger, etc. with a single LitNumber
  constructor with a LitNumType field
- Support built-in Natural literals
- Add desugar warning for negative literals
- Move Maybe(..) from GHC.Base to GHC.Maybe for module dependency
  reasons

This patch introduces only a few rules for Natural literals (compared
to Integer's rules). Factorization of the built-in rules for numeric
literals will be done in another patch as this one is already big to
review.

Test Plan:
  validate
  test build with integer-simple

Reviewers: hvr, bgamari, goldfire, Bodigrim, simonmar

Reviewed By: bgamari

Subscribers: phadej, simonpj, RyanGlScott, carter, hsyl20, rwbarton,
thomie

GHC Trac Issues: #14170, #14465

Differential Revision: https://phabricator.haskell.org/D4212

Cache `TypeRep k` in each `TrApp` or `TrTyCon` constructor of
`TypeRep (a :: k)`. This makes `typeRepKind` cheap.

With this change, we won't need any special effort to deserialize
typereps efficiently. The downside, of course, is that we make
`TypeRep`s slightly larger.

Reviewers: austin, hvr, bgamari, simonpj

Reviewed By: bgamari, simonpj

Subscribers: carter, simonpj, rwbarton, thomie

GHC Trac Issues: #14254

Differential Revision: https://phabricator.haskell.org/D4085

This is a preparatory refactoring for Semigroup=>Monoid
as it prevents a messy .hs-boot file which would interact
inconveniently with the buildsystem...

be3d7f66 added Show
instance for Callstack.

That made a couple of error messages to drift as:

             instance Show Ordering -- Defined in ‘GHC.Show’
             instance Show Integer -- Defined in ‘GHC.Show’
             ...plus 23 others
    -        ...plus 20 instances involving out-of-scope types
    +        ...plus 21 instances involving out-of-scope types

Signed-off-by: Sergei Trofimovich <siarheit@google.com>

Previously "types" was inappropriately made plural instead of
"instance",

    instance Eq Ordering -- Defined in ‘GHC.Classes’
    ...plus 24 others
    ...plus 13 instance involving out-of-scope typess

Test Plan:
```
ghci> import GHC.Stack
ghci> SrcLoc "f" "b" "c" 1 2 3 4
SrcLoc {srcLocPackage = "f", srcLocModule = "b", srcLocFile = "c",
srcLocStartLine = 1, srcLocStartCol = 2, srcLocEndLine = 3,
srcLocEndCol = 4}
```

Reviewers: austin, hvr, bgamari

Reviewed By: bgamari

Subscribers: thomie

Projects: #ghc

Differential Revision: https://phabricator.haskell.org/D1886

GHC Trac Issues: #11510

The idea here is described in [wiki:Typechecker]. Briefly,
this refactor keeps solid track of "synthesis" mode vs
"checking" in GHC's bidirectional type-checking algorithm.
When in synthesis mode, the expected type is just an IORef
to write to.

In addition, this patch does a significant reworking of
RebindableSyntax, allowing much more freedom in the types
of the rebindable operators. For example, we can now have
`negate :: Int -> Bool` and
`(>>=) :: m a -> (forall x. a x -> m b) -> m b`. The magic
is in tcSyntaxOp.

This addresses tickets #11397, #11452, and #11458.

Tests:
  typecheck/should_compile/{RebindHR,RebindNegate,T11397,T11458}
  th/T11452

Ben Gamari authored 9 years ago and Ben Gamari committed 9 years ago

Commit 547c5971 modifies the
pretty-printer to render names from a set of core packages (`base`,
`ghc-prim`, `template-haskell`) as unqualified. The idea here was that
many of these names typically are not in scope but are well-known by the
user and therefore qualification merely introduces noise.

This, however, is a very large hammer and potentially breaks any
consumer who relies on parsing GHC output (hence #11208). This commit
partially reverts this change, now only printing `Constraint` (which
appears quite often in errors) as unqualified.

Fixes #11208.

Updates tests in `array` submodule.

Test Plan: validate

Reviewers: hvr, thomie, austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1619

GHC Trac Issues: #11208

Ben Gamari authored 9 years ago and Ben Gamari committed 9 years ago

This is the second attempt at merging D757.

This patch implements the idea floated in Trac #9858, namely that we
should generate type-representation information at the data type
declaration site, rather than when solving a Typeable constraint.

However, this turned out quite a bit harder than I expected. I still
think it's the right thing to do, and it's done now, but it was quite
a struggle.

See particularly

 * Note [Grand plan for Typeable] in TcTypeable (which is a new module)
 * Note [The overall promotion story] in DataCon (clarifies existing
stuff)

The most painful bit was that to generate Typeable instances (ie
TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
etc:

 * We need to have enough data types around to *define* a TyCon
 * Many of these types are wired-in

Also, to minimise the code generated for each data type, I wanted to
generate pure data, not CAFs with unpackCString# stuff floating about.

Performance
~~~~~~~~~~~
Three perf/compiler tests start to allocate quite a bit more. This isn't
surprising, because they all allocate zillions of data types, with
practically no other code, esp. T1969

 * T1969:    GHC allocates 19% more
 * T4801:    GHC allocates 13% more
 * T5321FD:  GHC allocates 13% more
 * T9675:    GHC allocates 11% more
 * T783:     GHC allocates 11% more
 * T5642:    GHC allocates 10% more

I'm treating this as acceptable. The payoff comes in Typeable-heavy
code.

Remaining to do
~~~~~~~~~~~~~~~

 * I think that "TyCon" and "Module" are over-generic names to use for
   the runtime type representations used in GHC.Typeable. Better might
be
   "TrTyCon" and "TrModule". But I have not yet done this

 * Add more info the the "TyCon" e.g. source location where it was
   defined

 * Use the new "Module" type to help with Trac Trac #10068

 * It would be possible to generate TyConRepName (ie Typeable
   instances) selectively rather than all the time. We'd need to persist
   the information in interface files. Lacking a motivating reason I
have
   not done this, but it would not be difficult.

Refactoring
~~~~~~~~~~~
As is so often the case, I ended up refactoring more than I intended.
In particular

 * In TyCon, a type *family* (whether type or data) is repesented by a
   FamilyTyCon
     * a algebraic data type (including data/newtype instances) is
       represented by AlgTyCon This wasn't true before; a data family
       was represented as an AlgTyCon. There are some corresponding
       changes in IfaceSyn.

     * Also get rid of the (unhelpfully named) tyConParent.

 * In TyCon define 'Promoted', isomorphic to Maybe, used when things are
   optionally promoted; and use it elsewhere in GHC.

 * Cleanup handling of knownKeyNames

 * Each TyCon, including promoted TyCons, contains its TyConRepName, if
   it has one. This is, in effect, the name of its Typeable instance.

Updates haddock submodule

Test Plan: Let Harbormaster validate

Reviewers: austin, hvr, goldfire

Subscribers: goldfire, thomie

Differential Revision: https://phabricator.haskell.org/D1404

GHC Trac Issues: #9858

This reverts commit bef2f03e.

This merge was botched

Also reverts haddock submodule.

This patch implements the idea floated in Trac #9858, namely that we
should generate type-representation information at the data type
declaration site, rather than when solving a Typeable constraint.

However, this turned out quite a bit harder than I expected. I still
think it's the right thing to do, and it's done now, but it was quite
a struggle.

See particularly

 * Note [Grand plan for Typeable] in TcTypeable (which is a new module)
 * Note [The overall promotion story] in DataCon (clarifies existing stuff)

The most painful bit was that to generate Typeable instances (ie
TyConRepName bindings) for every TyCon is tricky for types in ghc-prim
etc:

 * We need to have enough data types around to *define* a TyCon
 * Many of these types are wired-in

Also, to minimise the code generated for each data type, I wanted to
generate pure data, not CAFs with unpackCString# stuff floating about.

Performance
~~~~~~~~~~~
Three perf/compiler tests start to allocate quite a bit more. This isn't
surprising, because they all allocate zillions of data types, with
practically no other code, esp. T1969

 * T3294:   GHC allocates 110% more (filed #11030 to track this)
 * T1969:   GHC allocates 30% more
 * T4801:   GHC allocates 14% more
 * T5321FD: GHC allocates 13% more
 * T783:    GHC allocates 12% more
 * T9675:   GHC allocates 12% more
 * T5642:   GHC allocates 10% more
 * T9961:   GHC allocates 6% more

 * T9203:   Program allocates 54% less

I'm treating this as acceptable. The payoff comes in Typeable-heavy
code.

Remaining to do
~~~~~~~~~~~~~~~

 * I think that "TyCon" and "Module" are over-generic names to use for
   the runtime type representations used in GHC.Typeable. Better might be
   "TrTyCon" and "TrModule". But I have not yet done this

 * Add more info the the "TyCon" e.g. source location where it was
   defined

 * Use the new "Module" type to help with Trac Trac #10068

 * It would be possible to generate TyConRepName (ie Typeable
   instances) selectively rather than all the time. We'd need to persist
   the information in interface files. Lacking a motivating reason I have
   not done this, but it would not be difficult.

Refactoring
~~~~~~~~~~~
As is so often the case, I ended up refactoring more than I intended.
In particular

 * In TyCon, a type *family* (whether type or data) is repesented by a
   FamilyTyCon
     * a algebraic data type (including data/newtype instances) is
       represented by AlgTyCon This wasn't true before; a data family
       was represented as an AlgTyCon. There are some corresponding
       changes in IfaceSyn.

     * Also get rid of the (unhelpfully named) tyConParent.

 * In TyCon define 'Promoted', isomorphic to Maybe, used when things are
   optionally promoted; and use it elsewhere in GHC.

 * Cleanup handling of knownKeyNames

 * Each TyCon, including promoted TyCons, contains its TyConRepName, if
   it has one. This is, in effect, the name of its Typeable instance.

Requires update of the haddock submodule.

Differential Revision: https://phabricator.haskell.org/D757

Improved error messages are only printed when the old message would be
"No instance for...", since they're not as helpful for "Could not deduce..."

No special test case as error messages are tested by other tests already.

Signed-off-by: David Kraeutmann <kane@kane.cx>

Reviewed By: austin, goldfire

Differential Revision: https://phabricator.haskell.org/D1182

GHC Trac Issues: #10733

For details see #6018, Phab:D202 and the wiki page:

https://ghc.haskell.org/trac/ghc/wiki/InjectiveTypeFamilies

This patch also wires-in Maybe data type and updates haddock submodule.

Test Plan: ./validate

Reviewers: simonpj, goldfire, austin, bgamari

Subscribers: mpickering, bgamari, alanz, thomie, goldfire, simonmar,
             carter

Differential Revision: https://phabricator.haskell.org/D202

GHC Trac Issues: #6018

Summary: See Note [Displaying potential instances].

Reviewers: austin

Subscribers: KaneTW, thomie

Differential Revision: https://phabricator.haskell.org/D1176

These two facilities provide some means to avoid the double-breakage caused by
first by the deprecation (see #2496), and then again by the actual future
field-removal.

See also

  https://groups.google.com/d/msg/haskell-core-libraries/q9H-QlL_gnE/4lbb_mBjre8J

for details about this library addition.

Reviewed By: ekmett

Differential Revision: https://phabricator.haskell.org/D577

Summary:
The intent of this commit is to make test suite cases more stable, so that
it doesn't matter what order we load interface files in, the test output
doesn't change.

Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

Test Plan: validate

Reviewers: simonpj, austin

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D484

I this this arises from my de-orphaning the Enum Word instance

Also update a few tests, since containers now has IsList instances.

Signed-off-by: Austin Seipp <austin@well-typed.com>

Now that we're in development mode, Applicative will soon be a
superclass of Monad in HEAD. So let's go ahead and deprecate the
-fno-warn-amp flag, remove the checks, and tweak a few tests

Signed-off-by: Austin Seipp <austin@well-typed.com>

This matches GCC's choice of Unicode quotation marks (i.e. U+2018 and U+2019)
and therefore looks more familiar on the console. This addresses #2507.

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

The perf tests can probably be rechecked and tightened a little; I fixed
them with AMP the other day but some changes since then have made them
wibble perhaps.

Signed-off-by: Austin Seipp <austin@well-typed.com>