- rebase to main

- update err_deduced_non_class_template_specialization_type to include alias templates
- update cxx_status.html
- fix a typo in ReleaseNotes

Author: hokein

clang/docs/ReleaseNotes.rst

@@ -91,7 +91,7 @@ C++20 Feature Support
   current module units.
   Fixes `#84002 <https://github.com/llvm/llvm-project/issues/84002>`_.
 
-- Initial support for class template argument deduciton (CTAD) for type alias
+- Initial support for class template argument deduction (CTAD) for type alias
   templates (`P1814R0 <https://wg21.link/p1814r0>`_).
   (#GH54051).
 

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2515,10 +2515,11 @@ def err_deduced_class_template_compound_type : Error<
   "cannot %select{form pointer to|form reference to|form array of|"
   "form function returning|use parentheses when declaring variable with}0 "
   "deduced class template specialization type">;
-def err_deduced_non_class_template_specialization_type : Error<
+def err_deduced_non_class_or_alias_template_specialization_type : Error<
   "%select{<error>|function template|variable template|alias template|"
   "template template parameter|concept|template}0 %1 requires template "
-  "arguments; argument deduction only allowed for class templates">;
+  "arguments; argument deduction only allowed for class templates or alias "
+  "templates">;
 def err_deduced_class_template_ctor_ambiguous : Error<
   "ambiguous deduction for template arguments of %0">;
 def err_deduced_class_template_ctor_no_viable : Error<

clang/lib/Sema/SemaInit.cpp

@@ -10751,9 +10751,8 @@ QualType Sema::DeduceTemplateSpecializationFromInitializer(
     }
   }
   if (!Template) {
-    // FIXME: update the diagnostic message to include C++20 alias templates
     Diag(Kind.getLocation(),
-         diag::err_deduced_non_class_template_specialization_type)
+         diag::err_deduced_non_class_or_alias_template_specialization_type)
       << (int)getTemplateNameKindForDiagnostics(TemplateName) << TemplateName;
     if (auto *TD = TemplateName.getAsTemplateDecl())
       NoteTemplateLocation(*TD);

clang/www/cxx_status.html

@@ -843,7 +843,13 @@ <h2 id="cxx20">C++20 implementation status</h2>
     <tr>
       <td>Class template argument deduction for alias templates</td>
       <td><a href="https://wg21.link/p1814r0">P1814R0</a></td>
-      <td class="none" align="center">No</td>
+      <td class="partial" align="center">
+        <details>
+          <summary>Clang 19 (Partial)</summary>
+          The associated constraints (over.match.class.deduct#3.3) for the
+          synthesized deduction guides are not yet implemented.
+        </details>
+      </td>
     </tr>
     <tr>
       <td>Permit conversions to arrays of unknown bound</td>