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<div class="content">
<h3 style="margin-top: 20px; margin-bottom: 10px;">
Vladislav Zavialov pushed to branch wip/int-index/visibility-check at <a href="https://gitlab.haskell.org/ghc/ghc">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/0c990e13c36b7be7d3bd3af050ad49182a028f21">0c990e13</a></strong>
<div>
<span> by Pierre Le Marre </span> <i> at 2023-04-06T10:16:29+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add release note for GHC.Unicode refactor in base-4.18.
Also merge CLC proposal 130 in base-4.19 with CLC proposal 59 in
base-4.18 and add proper release date.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cbbfb283dc58f6d582638ee60a96dc5c4b8acc4a">cbbfb283</a></strong>
<div>
<span> by Alex Dixon </span> <i> at 2023-04-07T18:27:45-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Improve documentation for ($) (#22963)
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5193c2b00194a4f536f0c31fe48ef4648b55a416">5193c2b0</a></strong>
<div>
<span> by Alex Dixon </span> <i> at 2023-04-07T18:27:45-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Remove trailing whitespace from ($) commentary
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b384523bab0650ba1e6b09f3c7aa64a92a90fe3b">b384523b</a></strong>
<div>
<span> by Sebastian Graf </span> <i> at 2023-04-07T18:27:45-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Adjust wording wrt representation polymorphism of ($)</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6a788f0ad465cf49673b187c5feeae80b738ce54">6a788f0a</a></strong>
<div>
<span> by Torsten Schmits </span> <i> at 2023-04-07T22:29:28-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add structured error messages for GHC.Tc.TyCl.Utils
Tracking ticket: #20117
MR: !10251
This converts uses of `mkTcRnUnknownMessage` to newly added constructors
of `TcRnMessage`.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3ba77b369a170ba68f4eb5c8f3ae13e03dcbb28d">3ba77b36</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-04-07T22:30:07-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Renamer: don't call addUsedGRE on an exact Name
When looking up a record field in GHC.Rename.Env.lookupRecFieldOcc,
we could end up calling addUsedGRE on an exact Name, which would then
lead to a panic in the bestImport function: it would be incapable of
processing a GRE which is not local but also not brought into scope
by any imports (as it is referred to by its unique instead).
Fixes #23240
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bc4795d207c132fbfe118958f7f39b140115f5bd">bc4795d2</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-04-11T19:24:54-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add support for -debug in the testsuite
Confusingly, GhcDebugged referred to GhcDebugAssertions.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b7474b57830261a94903da61bb2df33022c11357">b7474b57</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-04-11T19:24:54-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add missing cases in -Di prettyprinter
Fixes #23142
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6c3926167dc6c2978531ecac06e1eda50874297a">6c392616</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2023-04-11T19:25:31-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>compiler: make WasmCodeGenM an instance of MonadUnique
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/05d26a650b6e9e1169b42376fe54bb00850722f2">05d26a65</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2023-04-11T19:25:31-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>compiler: apply cmm node-splitting for wasm backend
This patch applies cmm node-splitting for wasm32 NCG, which is
required when handling irreducible CFGs. Fixes #23237.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f1892cc0c142e74640c320795493161d9321387f">f1892cc0</a></strong>
<div>
<span> by Bodigrim </span> <i> at 2023-04-11T19:26:09-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Set base 'maintainer' field to CLC
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ecf22da3c6d992d76fbb8e970b4ffbabb445d38a">ecf22da3</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-11T19:26:45-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Clarify a couple of Notes about 'nospec'
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ebd8918b7c50ae51921664e24fac0de4376ffcf9">ebd8918b</a></strong>
<div>
<span> by Oleg Grenrus </span> <i> at 2023-04-12T12:32:57-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Allow generation of TTH syntax with TH
In other words allow generation of typed splices and brackets with
Untyped Template Haskell.
That is useful in cases where a library is build with TTH in mind,
but we still want to generate some auxiliary declarations,
where TTH cannot help us, but untyped TH can.
Such example is e.g. `staged-sop` which works with TTH,
but we would like to derive `Generic` declarations with TH.
An alternative approach is to use `unsafeCodeCoerce`, but then the
derived `Generic` instances would be type-checked only at use sites,
i.e. much later. Also `-ddump-splices` output is quite ugly:
user-written instances would use TTH brackets, not `unsafeCodeCoerce`.
This commit doesn't allow generating of untyped template splices
and brackets with untyped TH, as I don't know why one would want to do
that (instead of merging the splices, e.g.)
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/690d0225d297a8c5c423ec4e63ee709df9d96d47">690d0225</a></strong>
<div>
<span> by Rodrigo Mesquita </span> <i> at 2023-04-12T12:33:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add regression test for #23229
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/593218794199e23cdfc1a94200cbb9f404e28720">59321879</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-13T08:50:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add quotRem rules (#22152)
case quotRemInt# x y of
(# q, _ #) -> body
====>
case quotInt# x y of
q -> body
case quotRemInt# x y of
(# _, r #) -> body
====>
case remInt# x y of
r -> body
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4dd021227559e1bc70cdaed12e45ff5459c33d27">4dd02122</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-13T08:50:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add quot folding rule (#22152)
(x / l1) / l2
l1 and l2 /= 0
l1*l2 doesn't overflow
==> x / (l1 * l2)
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1148ac723d6a879593dc4e7941a49b8e74e4c7d7">1148ac72</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-13T08:50:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Make Int64/Word64 division ok for speculation too.
Only when the divisor is definitely non-zero.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8af401ccfbe28d7bbfc493c0097834e9c66a36b0">8af401cc</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-13T08:50:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Make WordQuotRem2Op ok-for-speculation too
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/27d2978e5412f2bef4448e208182a03137dd5ee8">27d2978e</a></strong>
<div>
<span> by Josh Meredith </span> <i> at 2023-04-13T08:51:09-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Base/JS: GHC.JS.Foreign.Callback module (issue 23126)
* Add the Callback module for "exporting" Haskell functions
to be available to plain JavaScript code
* Fix some primitives defined in GHC.JS.Prim
* Add a JavaScript section to the user guide with instructions
on how to use the JavaScript FFI, building up to using Callbacks
to interact with the browser
* Add tests for the JavaScript FFI and Callbacks
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a34aa8da1293f997ce9212ccdc2ec56df4a2e9c1">a34aa8da</a></strong>
<div>
<span> by Adam Sandberg Ericsson </span> <i> at 2023-04-14T04:17:52-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>rts: improve memory ordering and add some comments in the StablePtr implementation
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d7a768a415c3bd575a20b20ae9a3953aa5886ed7">d7a768a4</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-04-14T04:18:28-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>docs: Generate docs/index.html with version number
* Generate docs/index.html to include the version of the ghc library
* This also fixes the packageVersions interpolations which were
- Missing an interpolation for `LIBRARY_ghc_VERSION`
- Double quoting the version so that "9.7" was being inserted.
Fixes #23121
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d48fbfea5f7b760ec3d13dd2947257986c095b75">d48fbfea</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-14T04:19:05-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Stop if type constructors have kind errors
Otherwise we get knock-on errors, such as #23252.
This makes GHC fail a bit sooner, and I have not attempted to add
recovery code, to add a fake TyCon place of the erroneous one,
in an attempt to get more type errors in one pass. We could
do that (perhaps) if there was a call for it.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2371d6b2d178895cc97f7bfebf489af4a095241b">2371d6b2</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-14T20:01:02+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Major refactor in the handling of equality constraints
This MR substantially refactors the way in which the constraint
solver deals with equality constraints. The big thing is:
* Intead of a pipeline in which we /first/ canonicalise and /then/
interact (the latter including performing unification) the two steps
are more closely integreated into one. That avoids the current
rather indirect communication between the two steps.
The proximate cause for this refactoring is fixing #22194, which involve
solving [W] alpha[2] ~ Maybe (F beta[4])
by doing this:
alpha[2] := Maybe delta[2]
[W] delta[2] ~ F beta[4]
That is, we don't promote beta[4]! This is very like introducing a cycle
breaker, and was very awkward to do before, but now it is all nice.
See GHC.Tc.Utils.Unify Note [Promotion and level-checking] and
Note [Family applications in canonical constraints].
The big change is this:
* Several canonicalisation checks (occurs-check, cycle-breaking,
checking for concreteness) are combined into one new function:
GHC.Tc.Utils.Unify.checkTyEqRhs
This function is controlled by `TyEqFlags`, which says what to do
for foralls, type families etc.
* `canEqCanLHSFinish` now sees if unification is possible, and if so,
actually does it: see `canEqCanLHSFinish_try_unification`.
There are loads of smaller changes:
* The on-the-fly unifier `GHC.Tc.Utils.Unify.unifyType` has a
cheap-and-cheerful version of `checkTyEqRhs`, called
`simpleUnifyCheck`. If `simpleUnifyCheck` succeeds, it can unify,
otherwise it defers by emitting a constraint. This is simpler than
before.
* I simplified the swapping code in `GHC.Tc.Solver.Equality.canEqCanLHS`.
Especially the nasty stuff involving `swap_for_occurs` and
`canEqTyVarFunEq`. Much nicer now. See
Note [Orienting TyVarLHS/TyFamLHS]
Note [Orienting TyFamLHS/TyFamLHS]
* Added `cteSkolemOccurs`, `cteConcrete`, and `cteCoercionHole` to the
problems that can be discovered by `checkTyEqRhs`.
* I fixed #23199 `pickQuantifiablePreds`, which actually allows GHC to
to accept both cases in #22194 rather than rejecting both.
Yet smaller:
* Added a `synIsConcrete` flag to `SynonymTyCon` (alongside `synIsFamFree`)
to reduce the need for synonym expansion when checking concreteness.
Use it in `isConcreteType`.
* Renamed `isConcrete` to `isConcreteType`
* Defined `GHC.Core.TyCo.FVs.isInjectiveInType` as a more efficient
way to find if a particular type variable is used injectively than
finding all the injective variables. It is called in
`GHC.Tc.Utils.Unify.definitely_poly`, which in turn is used quite a
lot.
* Moved `rewriterView` to `GHC.Core.Type`, so we can use it from the
constraint solver.
Fixes #22194, #23199
Compile times decrease by an average of 0.1%; but there is a 7.4%
drop in compiler allocation on T15703.
Metric Decrease:
T15703
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/99b2734b8a167d27d0066b331bfb4cf220326ce0">99b2734b</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-14T20:01:02+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add some documentation about redundant constraints
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3f2d0eb826cbd6414fe2f31085aec8e20fb2976f">3f2d0eb8</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-14T20:01:02+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Improve partial signatures
This MR fixes #23223. The changes are in two places:
* GHC.Tc.Bind.checkMonomorphismRestriction
See the new `Note [When the MR applies]`
We now no longer stupidly attempt to apply the MR when the user
specifies a context, e.g. f :: Eq a => _ -> _
* GHC.Tc.Solver.decideQuantification
See rewritten `Note [Constraints in partial type signatures]`
Fixing this bug apparently breaks three tests:
* partial-sigs/should_compile/T11192
* partial-sigs/should_fail/Defaulting1MROff
* partial-sigs/should_fail/T11122
However they are all symptoms of #23232, so I'm marking them as
expect_broken(23232).
I feel happy about this MR. Nice.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/23e2a8a0d7e626bcc327baab029e8d3ee2c5729b">23e2a8a0</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-14T20:01:02+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Make approximateWC a bit cleverer
This MR fixes #23224: making approximateWC more clever
See the long `Note [ApproximateWC]` in GHC.Tc.Solver
All this is delicate and ad-hoc -- but it /has/ to be: we are
talking about inferring a type for a binding in the presence of
GADTs, type families and whatnot: known difficult territory.
We just try as hard as we can.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2c04024617f1ee4c76844cfe0a886bab87c23bd0">2c040246</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-04-15T00:57:14-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>docs: Update template-haskell docs to use Code Q a rather than Q (TExp a)
Since GHC Proposal #195, the type of [|| ... ||] has been Code Q a
rather than Q (TExp a). The documentation in the `template-haskell`
library wasn't updated to reflect this change.
Fixes #23148
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0da18eb79540181ae9835e73d52ba47ec79fff6b">0da18eb7</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-04-15T14:35:53+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Show an error when we cannot default a concrete tyvar
Fixes #23153
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bad2f8b8aa84241e523577062e2b69090efccb32">bad2f8b8</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-04-15T15:14:36+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Handle ConcreteTvs in inferResultToType
inferResultToType was discarding the ir_frr information, which meant
some metavariables ended up being MetaTvs instead of ConcreteTvs.
This function now creates new ConcreteTvs as necessary, instead of
always creating MetaTvs.
Fixes #23154
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3b0ea4809d92581a10e0e501a6fbd7339e8922bf">3b0ea480</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-16T18:12:20-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Transfer DFunId_ness onto specialised bindings
Whether a binding is a DFunId or not has consequences for the `-fdicts-strict`
flag, essentially if we are doing demand analysis for a DFunId then `-fdicts-strict` does
not apply because the constraint solver can create recursive groups of dictionaries.
In #22549 this was fixed for the "normal" case, see
Note [Do not strictify the argument dictionaries of a dfun].
However the loop still existed if the DFunId was being specialised.
The problem was that the specialiser would specialise a DFunId and
turn it into a VanillaId and so the demand analyser didn't know to
apply special treatment to the binding anymore and the whole recursive
group was optimised to bottom.
The solution is to transfer over the DFunId-ness of the binding in the specialiser so
that the demand analyser knows not to apply the `-fstrict-dicts`.
Fixes #22549
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a1371ebb53a8206d6d99ac0d9bff4ed8a3043498">a1371ebb</a></strong>
<div>
<span> by Oleg Grenrus </span> <i> at 2023-04-16T18:12:59-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add import lists to few GHC.Driver.Session imports
Related to https://gitlab.haskell.org/ghc/ghc/-/issues/23261.
There are a lot of GHC.Driver.Session which only use DynFlags,
but not the parsing code.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/51479ceb31b8bfef15b966de7cfd64d1fdb22257">51479ceb</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-04-17T08:08:48-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Account for special GHC.Prim import in warnUnusedPackages
The GHC.Prim import is treated quite specially primarily because there
isn't an interface file for GHC.Prim. Therefore we record separately in
the ModSummary if it's imported or not so we don't go looking for it.
This logic hasn't made it's way to `-Wunused-packages` so if you
imported GHC.Prim then the warning would complain you didn't use
`-package ghc-prim`.
Fixes #23212
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1532a8b2b222fee73959a0760ac8867be7f19ce6">1532a8b2</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-04-17T08:09:24-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Add regression test for #23199
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0158c5f10869f567091c4f0cd9b127c0dc5cc413">0158c5f1</a></strong>
<div>
<span> by Ryan Scott </span> <i> at 2023-04-17T18:43:27-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>validDerivPred: Reject exotic constraints in IrredPreds
This brings the `IrredPred` case in sync with the treatment of `ClassPred`s as
described in `Note [Valid 'deriving' predicate]` in `GHC.Tc.Validity`. Namely,
we should reject `IrredPred`s that are inferred from `deriving` clauses whose
arguments contain other type constructors, as described in `(VD2) Reject exotic
constraints` of that Note. This has the nice property that `deriving` clauses
whose inferred instance context mention `TypeError` will now emit the type
error in the resulting error message, which better matches existing intuitions
about how `TypeError` should work.
While I was in town, I noticed that much of `Note [Valid 'deriving' predicate]`
was duplicated in a separate `Note [Exotic derived instance contexts]` in
`GHC.Tc.Deriv.Infer`. I decided to fold the latter Note into the former so that
there is a single authority on describing the conditions under which an
inferred `deriving` constraint can be considered valid.
This changes the behavior of `deriving` in a way that existing code might
break, so I have made a mention of this in the GHC User's Guide. It seems very,
very unlikely that much code is relying on this strange behavior, however, and
even if there is, there is a clear, backwards-compatible migration path using
`StandaloneDeriving`.
Fixes #22696.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1036481824fed7f8d5c9f70816b3dadd22098e42">10364818</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-04-17T18:44:03-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Misc cleanup
- Use dedicated list functions
- Make cloneBndrs and cloneRecIdBndrs monadic
- Fix invalid haddock comments in libraries/base
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5e1d33d7a428965c7024290cebb3d77b84230169">5e1d33d7</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-04-18T10:31:02-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Convert interface file loading errors into proper diagnostics
This patch converts all the errors to do with loading interface files
into proper structured diagnostics.
* DriverMessage: Sometimes in the driver we attempt to load an interface
file so we embed the IfaceMessage into the DriverMessage.
* TcRnMessage: Most the time we are loading interface files during
typechecking, so we embed the IfaceMessage
This patch also removes the TcRnInterfaceLookupError constructor which
is superceded by the IfaceMessage, which is now structured compared to
just storing an SDoc before.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/df1a581188694479a583270548896245fc23b525">df1a5811</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-04-18T10:31:43-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Don't panic in ltPatersonSize
The function GHC.Tc.Utils.TcType.ltPatersonSize would panic when it
encountered a type family on the RHS, as usually these are not allowed
(type families are not allowed on the RHS of class instances or of
quantified constraints). However, it is possible to still encounter
type families on the RHS after doing a bit of constraint solving, as
seen in test case T23171. This could trigger the panic in the call to
ltPatersonSize in GHC.Tc.Solver.Canonical.mk_strict_superclasses, which
is involved in avoiding loopy superclass constraints.
This patch simply changes ltPatersonSize to return "I don't know, because
there's a type family involved" in these cases.
Fixes #23171
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d442ac053f9ac7dbcc32318802daf686f377fe3d">d442ac05</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-19T20:04:35-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>JS: fix thread-related primops
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7a96f90b20e9ea55bb305b20c73473ba75834f78">7a96f90b</a></strong>
<div>
<span> by Bryan Richter </span> <i> at 2023-04-19T20:05:11-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>CI: Disable abi-test-nightly
See #23269
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ab6c1d295cd9f492838dbd481ecc2a66bbd17393">ab6c1d29</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-19T20:05:50-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Testsuite: don't use obsolescent egrep (#22351)
Recent egrep displays the following message, breaking golden tests:
egrep: warning: egrep is obsolescent; using grep -E
Switch to using "grep -E" instead
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f15b0ce530bece8b242941a446fd381614bdd3cf">f15b0ce5</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-04-20T11:01:06-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>hadrian: Pass haddock file arguments in a response file
In !10119 CI was failing on windows because the command line was too
long. We can mitigate this by passing the file arguments to haddock in a
response file.
We can't easily pass all the arguments in a response file because the
`+RTS` arguments can't be placed in the response file.
Fixes #23273
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7012ec2facc632fe4966916f797e4d1f612d7318">7012ec2f</a></strong>
<div>
<span> by tocic </span> <i> at 2023-04-20T11:01:42-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Fix doc typo in GHC.Read.readList
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5c8731244bc13a3d813d2a4d53b3188b28dc8355">5c873124</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-04-20T18:33:34-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Implement -jsem: parallelism controlled by semaphores
See https://github.com/ghc-proposals/ghc-proposals/pull/540/ for a
complete description for the motivation for this feature.
The `-jsem` option allows a build tool to pass a semaphore to GHC which
GHC can use in order to control how much parallelism it requests.
GHC itself acts as a client in the GHC jobserver protocol.
```
GHC Jobserver Protocol
~~~~~~~~~~~~~~~~~~~~~~
This proposal introduces the GHC Jobserver Protocol. This protocol allows
a server to dynamically invoke many instances of a client process,
while restricting all of those instances to use no more than <n> capabilities.
This is achieved by coordination over a system semaphore (either a POSIX
semaphore [6]_ in the case of Linux and Darwin, or a Win32 semaphore [7]_
in the case of Windows platforms).
There are two kinds of participants in the GHC Jobserver protocol:
- The *jobserver* creates a system semaphore with a certain number of
available tokens.
Each time the jobserver wants to spawn a new jobclient subprocess, it **must**
first acquire a single token from the semaphore, before spawning
the subprocess. This token **must** be released once the subprocess terminates.
Once work is finished, the jobserver **must** destroy the semaphore it created.
- A *jobclient* is a subprocess spawned by the jobserver or another jobclient.
Each jobclient starts with one available token (its *implicit token*,
which was acquired by the parent which spawned it), and can request more
tokens through the Jobserver Protocol by waiting on the semaphore.
Each time a jobclient wants to spawn a new jobclient subprocess, it **must**
pass on a single token to the child jobclient. This token can either be the
jobclient's implicit token, or another token which the jobclient acquired
from the semaphore.
Each jobclient **must** release exactly as many tokens as it has acquired from
the semaphore (this does not include the implicit tokens).
```
Build tools such as cabal act as jobservers in the protocol and are
responsibile for correctly creating, cleaning up and managing the
semaphore.
Adds a new submodule (semaphore-compat) for managing and interacting
with semaphores in a cross-platform way.
Fixes #19349
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/52d3e9b4189440d26bad9c5a15f9420b67b1ca5b">52d3e9b4</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2023-04-20T18:34:11-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>rts: Initialize Array# header in listThreads#
Previously the implementation of listThreads# failed to initialize the
header of the created array, leading to various nastiness.
Fixes #23071
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1db30fe1dd38dd8ffedfadf3845706fcde02933b">1db30fe1</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2023-04-20T18:34:11-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>testsuite: Add test for #23071
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/dae514f9835f7fe8e6643f8759cc4d0b0af9a657">dae514f9</a></strong>
<div>
<span> by tocic </span> <i> at 2023-04-21T13:31:21-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Fix doc typos in libraries/base/GHC
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/113e21d763678ea7e7666b708e6c2dba7e52382f">113e21d7</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2023-04-21T13:32:01-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Testsuite: replace some js_broken/js_skip predicates with req_c
Using req_c is more precise.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/038bb03157cabf53bd08426cbd86a38486b9752d">038bb031</a></strong>
<div>
<span> by Krzysztof Gogolewski </span> <i> at 2023-04-21T18:03:04-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Minor doc fixes
- Add docs/index.html to .gitignore.
It is created by ./hadrian/build docs, and it was the only file
in Hadrian's templateRules not present in .gitignore.
- Mention that MultiWayIf supports non-boolean guards
- Remove documentation of optdll - removed in 2007, 763daed95
- Fix markdown syntax
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e826cdb213e9b900dfc8f604220d8f3538b98763">e826cdb2</a></strong>
<div>
<span> by amesgen </span> <i> at 2023-04-21T18:03:44-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>User's guide: DeepSubsumption is implied by Haskell{98,2010}
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e606979aca878513a54ce3b0e26467e3c3496dd6">e606979a</a></strong>
<div>
<span> by Vladislav Zavialov </span> <i> at 2023-04-23T19:31:21+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "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: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Ignore forall visibility in eqType (#22762)
Prior to this change, the equality relation on types took ForAllTyFlag
into account, making a distinction between:
1. forall a. blah
2. forall a -> blah
Not anymore.
This distinction is important in surface Haskell, but it has no meaning
in Core where type abstraction and type application are always explicit.
At the same time, if we are not careful to track this flag, Core Lint
will fail, as reported in #22762:
*** Core Lint errors : in result of TcGblEnv axioms ***
From-kind of Cast differs from kind of enclosed type
From-kind: forall (b :: Bool) -> *
Kind of enclosed type: forall {b :: Bool}. *
The solution is to compare types for equality modulo visibility (ForAllTyFlag).
Updated functions:
nonDetCmpType (worker for eqType)
eqDeBruijnType
tc_eq_type (worker for tcEqType)
can_eq_nc
In order to retain the distinction between visible and invisible forall
in user-written code, we introduce a new ad-hoc check: checkEqForallVis.
</pre>
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