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

Artem Pelenitsyn authored 3 years ago and Marge Bot committed 3 years ago

CLC proposal: https://github.com/haskell/core-libraries-committee/issues/33

The instances had `fail` implemented in terms of `error`, whereas the
idea of the `MonadFail` class is that the `fail` method should be
implemented in terms of the monad itself.

Herbert Valerio Riedel authored 6 years ago and Ben Gamari committed 6 years ago

As per https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail



Coauthored-by: Ben Gamari <ben@well-typed.com>

Vladislav Zavialov authored 6 years ago and Ben Gamari committed 6 years ago

Enabling -Werror=compat in the testsuite allows us to easily see the
impact that a new warning has on code. It also means that in the period
between adding the warning and making the actual breaking change, all
new test cases that are being added to the testsuite will be
forwards-compatible. This is good because it will make the actual
breaking change contain less irrelevant testsuite updates.

Things that -Wcompat warns about are things that are going to break in
the future, so we can be proactive and keep our testsuite
forwards-compatible.

This patch consists of two main changes:

* Add `TEST_HC_OPTS += -Werror=compat` to the testsuite configuration.
* Fix all broken test cases.

Test Plan: Validate

Reviewers: hvr, goldfire, bgamari, simonpj, RyanGlScott

Reviewed By: goldfire, RyanGlScott

Subscribers: rwbarton, carter

GHC Trac Issues: #15278

Differential Revision: https://phabricator.haskell.org/D5200

Herbert Valerio Riedel authored 6 years ago and Ben Gamari committed 6 years ago

Summary:
This contains two commits:

----

Make GHC's code-base compatible w/ `MonadFail`

There were a couple of use-sites which implicitly used pattern-matches
in `do`-notation even though the underlying `Monad` didn't explicitly
support `fail`

This refactoring turns those use-sites into explicit case
discrimations and adds an `MonadFail` instance for `UniqSM`
(`UniqSM` was the worst offender so this has been postponed for a
follow-up refactoring)

---

Turn on MonadFail desugaring by default

This finally implements the phase scheduled for GHC 8.6 according to

https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail#Transitionalstrategy

This also preserves some tests that assumed MonadFail desugaring to be
active; all ghc boot libs were already made compatible with this
`MonadFail` long ago, so no changes were needed there.

Test Plan: Locally performed ./validate --fast

Reviewers: bgamari, simonmar, jrtc27, RyanGlScott

Reviewed By: bgamari

Subscribers: bgamari, RyanGlScott, rwbarton, thomie, carter

Differential Revision: https://phabricator.haskell.org/D5028

In error messages like this
    • Couldn't match type ‘c’ with ‘f0 (a -> b)’
      ‘c’ is a rigid type variable bound by
        the type signature for:
          f :: ((a -> b) -> b) -> forall c. c -> a

we need to take case both to actually show that 'forall c',
and to make sure that its name lines with the 'c' in the
error message.

This has been shaky for some time, and this commit puts it on solid
ground.  See TcRnTypes: Note [SigSkol SkolemInfo]

The main changes are

* SigSkol gets an extra field that records the way in which the
  type signature was skolemised.

* The type in SigSkol is now the /un/-skolemised version

* pprSkolemInfo uses the info to make the tidy type line up
  nicely

Lots of error message wibbles!

Summary:
Add prettyprinter tests, which take a file, parse it, pretty print it,
re-parse the pretty printed version and then compare the original and
new ASTs (ignoring locations)

Updates haddock submodule to match the AST changes.

There are three issues outstanding

1. Extra parens around a context are not reproduced. This will require an
   AST change and will be done in a separate patch.

2. Currently if an `HsTickPragma` is found, this is not pretty-printed,
   to prevent noise in the output.

   I am not sure what the desired behaviour in this case is, so have left
   it as before. Test Ppr047 is marked as expected fail for this.

3. Apart from in a context, the ParsedSource AST keeps all the parens from
   the original source.  Something is happening in the renamer to remove the
   parens around visible type application, causing T12530 to fail, as the
   dumped splice decl is after the renamer.

   This needs to be fixed by keeping the parens, but I do not know where they
   are being removed.  I have amended the test to pass, by removing the parens
   in the expected output.

Test Plan: ./validate

Reviewers: goldfire, mpickering, simonpj, bgamari, austin

Reviewed By: simonpj, bgamari

Subscribers: simonpj, goldfire, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D2752

GHC Trac Issues: #3384

barrucadu authored 9 years ago and Herbert Valerio Riedel committed 9 years ago

Both gcc and clang tell which warning flag a reported warning can be
controlled with, this patch makes ghc do the same. More generally, this
allows for annotated compiler output, where an optional annotation is
displayed in brackets after the severity.

This also adds a new flag `-f(no-)show-warning-groups` to control
whether to show which warning-group (such as `-Wall` or `-Wcompat`)
a warning belongs to. This flag is on by default.

This implements #10752

Reviewed By: quchen, bgamari, hvr

Differential Revision: https://phabricator.haskell.org/D1943

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

Reviewers: bgamari, austin

Reviewed By: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1915

Herbert Valerio Riedel authored 9 years ago and Ben Gamari committed 9 years ago

This warning flag was recently introduced as part of #10751. However,
it was missed during code-review that almost all existing warning
flags use a plural-form, so for consistency this commit renames
that warning flag to `-Wmissing-monadfail-instances`.

Test Plan: local validate (still running)

Reviewers: quchen, goldfire, austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1842

GHC Trac Issues: #10751

This patch began as a modest refactoring of HsType and friends, to
clarify and tidy up exactly where quantification takes place in types.
Although initially driven by making the implementation of wildcards more
tidy (and fixing a number of bugs), I gradually got drawn into a pretty
big process, which I've been doing on and off for quite a long time.

There is one compiler performance regression as a result of all
this, in perf/compiler/T3064.  I still need to look into that.

* The principal driving change is described in Note [HsType binders]
  in HsType.  Well worth reading!

* Those data type changes drive almost everything else.  In particular
  we now statically know where

       (a) implicit quantification only (LHsSigType),
           e.g. in instance declaratios and SPECIALISE signatures

       (b) implicit quantification and wildcards (LHsSigWcType)
           can appear, e.g. in function type signatures

* As part of this change, HsForAllTy is (a) simplified (no wildcards)
  and (b) split into HsForAllTy and HsQualTy.  The two contructors
  appear when and only when the correponding user-level construct
  appears.  Again see Note [HsType binders].

  HsExplicitFlag disappears altogether.

* Other simplifications

     - ExprWithTySig no longer needs an ExprWithTySigOut variant

     - TypeSig no longer needs a PostRn name [name] field
       for wildcards

     - PatSynSig records a LHsSigType rather than the decomposed
       pieces

     - The mysterious 'GenericSig' is now 'ClassOpSig'

* Renamed LHsTyVarBndrs to LHsQTyVars

* There are some uninteresting knock-on changes in Haddock,
  because of the HsSyn changes

I also did a bunch of loosely-related changes:

* We already had type synonyms CoercionN/CoercionR for nominal and
  representational coercions.  I've added similar treatment for

      TcCoercionN/TcCoercionR

      mkWpCastN/mkWpCastN

  All just type synonyms but jolly useful.

* I record-ised ForeignImport and ForeignExport

* I improved the (poor) fix to Trac #10896, by making
  TcTyClsDecls.checkValidTyCl recover from errors, but adding a
  harmless, abstract TyCon to the envt if so.

* I did some significant refactoring in RnEnv.lookupSubBndrOcc,
  for reasons that I have (embarrassingly) now totally forgotten.
  It had to do with something to do with import and export

Updates haddock submodule.

Simplify and tidy up the MonadFail code.
See TcMatches.tcMonadFailOp

Less, code; and more robust.

This incidentally fixes a bug; see the change
to MonadFailErrors.stderr

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

Example error message:

    MonadFailErrors.hs:16:5: error:
        Could not deduce (MonadFail m)
          arising from a do statement
                       with the failable pattern ‘Just x’

Depends on D1248

Reviewers: austin, bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1489

This implements phase 1 of the MonadFail proposal (MFP, #10751).

- MonadFail warnings are all issued as desired, tunable with two new flags
- GHC was *not* made warning-free with `-fwarn-missing-monadfail-warnings`
  (but it's disabled by default right now)

Credits/thanks to
- Franz Thoma, whose help was crucial to implementing this
- My employer TNG Technology Consulting GmbH for partially funding us
  for this work

Reviewers: goldfire, austin, #core_libraries_committee, hvr, bgamari, fmthoma

Reviewed By: hvr, bgamari, fmthoma

Subscribers: thomie

Projects: #ghc

Differential Revision: https://phabricator.haskell.org/D1248

GHC Trac Issues: #10751