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<h3 style="margin-top: 20px; margin-bottom: 10px;">
Simon Peyton Jones pushed to branch wip/T20666 at <a href="https://gitlab.haskell.org/ghc/ghc" style="color: #1068bf;">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
Commits:
</h4>
<ul>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6e6adbe368f68968ff1733b56deb3386b8c97fde" style="color: #1068bf;">6e6adbe3</a></strong>
<div>
<span> by Jade Lovelace </span> <i> at 2023-01-11T00:55:30-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>Fix tcPluginRewrite example
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/faa5713818cddd0b206b5c2b98be4e241959be87" style="color: #1068bf;">faa57138</a></strong>
<div>
<span> by Jade Lovelace </span> <i> at 2023-01-11T00:55:31-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>fix missing haddock pipe
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0470ea7c92ad2330a9c6dfc8eae3a1dcad41dcb9" style="color: #1068bf;">0470ea7c</a></strong>
<div>
<span> by Florian Weimer </span> <i> at 2023-01-11T00:56:10-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b2857df4ee467c88162e5a6784ee1fb6e2038656" style="color: #1068bf;">b2857df4</a></strong>
<div>
<span> by HaskellMouse </span> <i> at 2023-01-11T00:56:52-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5f17e21af6368ec0e615af7de714a3194181f46a" style="color: #1068bf;">5f17e21a</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2023-01-11T00:57:27-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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. </pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bc1257750f507218059ac6bad05d9c96a8b88d67" style="color: #1068bf;">bc125775</a></strong>
<div>
<span> by Vladislav Zavialov </span> <i> at 2023-01-11T00:58:03-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/083f701553852c4460159cd6deb2515d3373714d" style="color: #1068bf;">083f7015</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-01-11T00:58:38-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/aed1974e92366ab8e117734f308505684f70cddf" style="color: #1068bf;">aed1974e</a></strong>
<div>
<span> by Richard Eisenberg </span> <i> at 2023-01-11T08:30:42+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.8125rem; color: #303030; position: relative; font-family: "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fafafa; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dbdbdb;'>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.
</pre>
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<a href="#6b7e521fe89077442c3d86c888eb96793606049a" style="color: #1068bf;">
compiler/GHC/CmmToAsm/Reg/Linear/JoinToTargets.hs
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<a href="#5596bb0f228bd2a308c4391df97375ae879430a8" style="color: #1068bf;">
compiler/GHC/Core/InstEnv.hs
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compiler/GHC/Core/Make.hs
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compiler/GHC/Core/Opt/WorkWrap.hs
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compiler/GHC/Core/TyCo/FVs.hs
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compiler/GHC/Driver/Flags.hs
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compiler/GHC/Rename/Env.hs
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compiler/GHC/Rename/Pat.hs
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compiler/GHC/Tc/Errors/Types.hs
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compiler/GHC/Tc/Solver/Canonical.hs
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compiler/GHC/Tc/Solver/InertSet.hs
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compiler/GHC/Tc/TyCl/Instance.hs
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compiler/GHC/Tc/Types.hs
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compiler/GHC/Tc/Types/Constraint.hs
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compiler/GHC/Tc/Types/Origin.hs
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compiler/GHC/Tc/Utils/Backpack.hs
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compiler/GHC/Tc/Utils/Instantiate.hs
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