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<h3 style="margin-top: 20px; margin-bottom: 10px;">
Marge Bot pushed to branch master at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
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Commits:
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<ul>
<li>
<strong style="font-weight: 600;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0b11cdc022ce33d089db95b2b2e7c1f4bb326d37">0b11cdc0</a></strong>
<div>
<span> by sheaf </span> <i> at 2024-10-31T08:38:55-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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;'>Assert that ctEvCoercion is called on an equality

Calling 'ctEvCoercion' on non-equality constraints is always incorrect.
We add an assertion to this function to detect such cases; for example
a type-checking plugin might erroneously do this.
</pre>
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1 changed file:
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<li class="file-stats">
<a href="#3b6d78a50c8462304f843b952a88e531718dbbd2">
compiler/GHC/Tc/Types/Constraint.hs
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Changes:
</h4>
<li id="3b6d78a50c8462304f843b952a88e531718dbbd2">
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0b11cdc022ce33d089db95b2b2e7c1f4bb326d37#3b6d78a50c8462304f843b952a88e531718dbbd2"><strong style="font-weight: 600;">compiler/GHC/Tc/Types/Constraint.hs</strong></a>
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<td class="line_content match" style="color: rgba(5,5,6,.24); padding: inherit;" bgcolor="#fbfafd">@@ -2306,8 +2306,10 @@ ctEvExpr ev@(CtWanted { ctev_dest = HoleDest _ })</td>
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<td class="new_line diff-line-num" data-linenumber="2306" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
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<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2306" class="line" lang="haskell"><span class="n" style="color: #333;">ctEvExpr</span> <span class="n" style="color: #333;">ev</span> <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">evId</span> <span class="p">(</span><span class="n" style="color: #333;">ctEvEvId</span> <span class="n" style="color: #333;">ev</span><span class="p">)</span></span>
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<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2307" class="line" lang="haskell"></span>
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<td class="new_line diff-line-num" data-linenumber="2308" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
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<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2308" class="line" lang="haskell"><span class="n" style="color: #333;">ctEvCoercion</span> <span class="o" style="font-weight: 600;">::</span> <span class="kt" style="color: #458; font-weight: 600;">HasDebugCallStack</span> <span class="o" style="font-weight: 600;">=></span> <span class="kt" style="color: #458; font-weight: 600;">CtEvidence</span> <span class="o" style="font-weight: 600;">-></span> <span class="kt" style="color: #458; font-weight: 600;">TcCoercion</span></span>
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<td class="old_line diff-line-num old" data-linenumber="2309" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: inherit;" align="right" bgcolor="#f9d7dc">
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<td class="new_line diff-line-num old" data-linenumber="2309" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: inherit;" align="right" bgcolor="#f9d7dc">
 
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<td class="line_content old" style="padding: inherit;" bgcolor="#fbe9eb"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>-<span id="LC2309" class="line" lang="haskell"><span class="n" style="color: #333;">ctEvCoercion</span> <span class="p">(</span><span class="kt" style="color: #458; font-weight: 600;">CtGiven</span> <span class="p">{</span> <span class="n" style="color: #333;">ctev_evar</span> <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">ev_id</span> <span class="p">})</span></span>
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<td class="new_line diff-line-num old" data-linenumber="2309" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: inherit;" align="right" bgcolor="#f9d7dc">
 
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<td class="line_content old" style="padding: inherit;" bgcolor="#fbe9eb"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>-<span id="LC2310" class="line" lang="haskell">  <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">mkCoVarCo</span> <span class="n" style="color: #333;">ev_id</span></span>
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<td class="new_line diff-line-num new" data-linenumber="2309" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: inherit;" align="right" bgcolor="#ddfbe6">
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<td class="line_content new" style="padding: inherit;" bgcolor="#ecfdf0"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>+<span id="LC2309" class="line" lang="haskell"><span class="n" style="color: #333;">ctEvCoercion</span> <span class="n" style="color: #333;">_given</span><span class="o" style="font-weight: 600;">@</span><span class="p">(</span><span class="kt" style="color: #458; font-weight: 600;">CtGiven</span> <span class="p">{</span> <span class="n" style="color: #333;">ctev_evar</span> <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">ev_id</span> <span class="p">})</span></span>
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<td class="new_line diff-line-num new" data-linenumber="2310" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: inherit;" align="right" bgcolor="#ddfbe6">
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<td class="line_content new" style="padding: inherit;" bgcolor="#ecfdf0"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>+<span id="LC2310" class="line" lang="haskell">  <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">assertPpr</span> <span class="p">(</span><span class="n" style="color: #333;">isCoVar</span> <span class="n" style="color: #333;">ev_id</span><span class="p">)</span></span>
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<td class="line_content new" style="padding: inherit;" bgcolor="#ecfdf0"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>+<span id="LC2311" class="line" lang="haskell">    <span class="p">(</span><span class="n" style="color: #333;">text</span> <span class="s" style="color: #d14;">"ctEvCoercion used on non-equality Given constraint:"</span> <span class="o" style="font-weight: 600;"><+></span> <span class="n" style="color: #333;">ppr</span> <span class="n" style="color: #333;">_given</span><span class="p">)</span></span>
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<td class="new_line diff-line-num new" data-linenumber="2312" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: inherit;" align="right" bgcolor="#ddfbe6">
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<td class="line_content new" style="padding: inherit;" bgcolor="#ecfdf0"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'>+<span id="LC2312" class="line" lang="haskell">  <span class="o" style="font-weight: 600;">$</span> <span class="n" style="color: #333;">mkCoVarCo</span> <span class="n" style="color: #333;">ev_id</span></span>
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<td class="new_line diff-line-num" data-linenumber="2313" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
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<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2313" class="line" lang="haskell"><span class="n" style="color: #333;">ctEvCoercion</span> <span class="p">(</span><span class="kt" style="color: #458; font-weight: 600;">CtWanted</span> <span class="p">{</span> <span class="n" style="color: #333;">ctev_dest</span> <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">dest</span> <span class="p">})</span></span>
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<td class="new_line diff-line-num" data-linenumber="2314" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
2314
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<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2314" class="line" lang="haskell">  <span class="o" style="font-weight: 600;">|</span> <span class="kt" style="color: #458; font-weight: 600;">HoleDest</span> <span class="n" style="color: #333;">hole</span> <span class="o" style="font-weight: 600;"><-</span> <span class="n" style="color: #333;">dest</span></span>
</pre></td>
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<td class="old_line diff-line-num" data-linenumber="2313" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
2313
</td>
<td class="new_line diff-line-num" data-linenumber="2315" style="width: 35px; color: rgba(5,5,6,.24); border-right-width: 1px; border-right-color: #ececef; border-right-style: solid; padding: inherit;" align="right" bgcolor="#fbfafd">
2315
</td>
<td class="line_content" style="padding: inherit;"><pre style='display: block; font-size: 14px; color: #28272d; position: relative; font-family: "GitLab Mono","JetBrains Mono","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: inherit; border-radius: 2px; margin: 0; padding: 0; border: inherit solid #dcdcde;'> <span id="LC2315" class="line" lang="haskell">  <span class="o" style="font-weight: 600;">=</span> <span class="c1" style="color: #998; font-style: italic;">-- ctEvCoercion is only called on type equalities</span></span>
</pre></td>
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