[Git][ghc/ghc][wip/T20666] 8 commits: Fix tcPluginRewrite example

Wed Jan 11 08:30:17 UTC 2023

Simon Peyton Jones pushed to branch wip/T20666 at Glasgow Haskell Compiler / GHC

Commits:
6e6adbe3 by Jade Lovelace at 2023-01-11T00:55:30-05:00
Fix tcPluginRewrite example

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faa57138 by Jade Lovelace at 2023-01-11T00:55:31-05:00
fix missing haddock pipe

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0470ea7c by Florian Weimer at 2023-01-11T00:56:10-05:00
m4/fp_leading_underscore.m4: Avoid implicit exit function declaration

And switch to a new-style function definition.

Fixes build issues with compilers that do not accept implicit function
declarations.

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b2857df4 by HaskellMouse at 2023-01-11T00:56:52-05:00
Added a new warning about compatibility with RequiredTypeArguments

This commit introduces a new warning
that indicates code incompatible with
future extension: RequiredTypeArguments.

Enabling this extension may break some code and the warning
will help to make it compatible in advance.

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5f17e21a by Ben Gamari at 2023-01-11T00:57:27-05:00
testsuite: Drop testheapalloced.c

As noted in #22414, this file (which appears to be a benchmark for
characterising the one-step allocator's MBlock cache) is currently 
unreferenced. Remove it.

Closes #22414. 
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bc125775 by Vladislav Zavialov at 2023-01-11T00:58:03-05:00
Introduce the TypeAbstractions language flag

GHC Proposals #448 "Modern scoped type variables"
and #425 "Invisible binders in type declarations"
introduce a new language extension flag: TypeAbstractions.

Part of the functionality guarded by this flag has already been
implemented, namely type abstractions in constructor patterns, but it
was guarded by a combination of TypeApplications and ScopedTypeVariables
instead of a dedicated language extension flag.

This patch does the following:

* introduces a new language extension flag TypeAbstractions
* requires TypeAbstractions for @a-syntax in constructor patterns
  instead of TypeApplications and ScopedTypeVariables
* creates a User's Guide page for TypeAbstractions and
  moves the "Type Applications in Patterns" section there

To avoid a breaking change, the new flag is implied by
ScopedTypeVariables and is retroactively added to GHC2021.

Metric Decrease:
    MultiLayerModulesTH_OneShot

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083f7015 by Krzysztof Gogolewski at 2023-01-11T00:58:38-05:00
Misc cleanup

- Remove unused mkWildEvBinder
- Use typeTypeOrConstraint - more symmetric and asserts that
  that the type is Type or Constraint
- Fix escape sequences in Python; they raise a deprecation warning
  with -Wdefault

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aed1974e by Richard Eisenberg at 2023-01-11T08:30:42+00:00
Refactor the treatment of loopy superclass dicts

This patch completely re-engineers how we deal with loopy superclass
dictionaries in instance declarations. It fixes #20666 and #19690

The highlights are

* Recognise that the loopy-superclass business should use precisely
  the Paterson conditions.  This is much much nicer.  See
  Note [Recursive superclasses] in GHC.Tc.TyCl.Instance

* With that in mind, define "Paterson-smaller" in
  Note [Paterson conditions] in GHC.Tc.Validity, and the new
  data type `PatersonSize` in GHC.Tc.Utils.TcType, along with
  functions to compute and compare PatsonSizes

* Use the new PatersonSize stuff when solving superclass constraints
  See Note [Solving superclass constraints] in GHC.Tc.TyCl.Instance

* In GHC.Tc.Solver.Monad.lookupInInerts, add a missing call to
  prohibitedSuperClassSolve.  This was the original cause of #20666.

* Treat (TypeError "stuff") as having PatersonSize zero. See
  Note [Paterson size for type family applications] in GHC.Tc.Utils.TcType.

* Treat the head of a Wanted quantified constraint in the same way
  as the superclass of an instance decl; this is what fixes #19690.
  See GHC.Tc.Solver.Canonical Note [Solving a Wanted forall-constraint]
  (Thanks to Matthew Craven for this insight.)

  This entailed refactoring the GivenSc constructor of CtOrigin a bit,
  to say whether it comes from an instance decl or quantified constraint.

* Some refactoring way in which redundant constraints are reported; we
  don't want to complain about the extra, apparently-redundant
  constraints that we must add to an instance decl because of the
  loopy-superclass thing.  I moved some work from GHC.Tc.Errors to
  GHC.Tc.Solver.

* Add a new section to the user manual to describe the loopy
  superclass issue and what rules it follows.

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30 changed files:

- compiler/GHC/CmmToAsm/Reg/Linear/JoinToTargets.hs
- compiler/GHC/Core/InstEnv.hs
- compiler/GHC/Core/Make.hs
- compiler/GHC/Core/Opt/WorkWrap.hs
- compiler/GHC/Core/TyCo/FVs.hs
- compiler/GHC/Core/Type.hs
- compiler/GHC/Driver/Flags.hs
- compiler/GHC/Driver/Session.hs
- compiler/GHC/HsToCore/Utils.hs
- compiler/GHC/Rename/Env.hs
- compiler/GHC/Rename/HsType.hs
- compiler/GHC/Rename/Pat.hs
- compiler/GHC/Tc/Deriv.hs
- compiler/GHC/Tc/Deriv/Infer.hs
- compiler/GHC/Tc/Errors.hs
- compiler/GHC/Tc/Errors/Ppr.hs
- compiler/GHC/Tc/Errors/Types.hs
- compiler/GHC/Tc/Gen/HsType.hs
- compiler/GHC/Tc/Solver.hs
- compiler/GHC/Tc/Solver/Canonical.hs
- compiler/GHC/Tc/Solver/InertSet.hs
- compiler/GHC/Tc/Solver/Interact.hs
- compiler/GHC/Tc/Solver/Monad.hs
- compiler/GHC/Tc/TyCl/Instance.hs
- compiler/GHC/Tc/Types.hs
- compiler/GHC/Tc/Types/Constraint.hs
- compiler/GHC/Tc/Types/Origin.hs
- compiler/GHC/Tc/Utils/Backpack.hs
- compiler/GHC/Tc/Utils/Instantiate.hs
- compiler/GHC/Tc/Utils/TcMType.hs

The diff was not included because it is too large.

View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/14aa3236f3828d4953d852d63a09c78084bfebc8...aed1974e92366ab8e117734f308505684f70cddf

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/14aa3236f3828d4953d852d63a09c78084bfebc8...aed1974e92366ab8e117734f308505684f70cddf
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