Revert "[Clang] Implement fix for DR2628"

This reverts commit 368b683.
llvm · Feb 24, 2023 · 233479f · 233479f
1 parent eb9440b
commit 233479f
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Showing 3 changed files with 11 additions and 12 deletions.
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
@@ -833,11 +833,6 @@ Concepts Specific Fixes:
 - Fixed an issue with concept requirement evaluation, where we incorrectly allowed implicit
   conversions to bool for a requirement.  (`#54524 <https://github.com/llvm/llvm-project/issues/54524>`_)
 
-- Respect constructor constraints during class template argument deduction (CTAD).
-  This is the suggested resolution to CWG DR2628.
-  (`#57646 <https://github.com/llvm/llvm-project/issues/57646>`_,
-  `#43829 <https://github.com/llvm/llvm-project/issues/43829>`_)
-
 - Fix a crash when emitting a concept-related diagnostic.
   (`#57415 <https://github.com/llvm/llvm-project/issues/57415>`_)
 

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
@@ -2540,8 +2540,6 @@ struct ConvertConstructorToDeductionGuideTransform {
                                       TInfo->getType(), TInfo, LocEnd, Ctor);
     Guide->setImplicit();
     Guide->setParams(Params);
-    if (Ctor && Ctor->getTrailingRequiresClause())
-      Guide->setTrailingRequiresClause(Ctor->getTrailingRequiresClause());
 
     for (auto *Param : Params)
       Param->setDeclContext(Guide);

diff --git a/clang/test/CXX/drs/dr26xx.cpp b/clang/test/CXX/drs/dr26xx.cpp
@@ -14,17 +14,23 @@ using enum E; // expected-error {{unknown type name E}}
 }
 }
 
-namespace dr2628 { // dr2628: yes open
+namespace dr2628 { // dr2628: no, this was reverted for the 16.x release
+                   // due to regressions, see the issue for more details:
+                   // https://github.com/llvm/llvm-project/issues/60777
 
 template <bool A = false, bool B = false>
 struct foo {
-  constexpr foo() requires (!A && !B) = delete; // #DR2628_CTOR
-  constexpr foo() requires (A || B) = delete;
+  // The expected notes below should be removed when dr2628 is fully implemented again
+  constexpr foo() requires (!A && !B) = delete; // expected-note {{candidate function [with A = false, B = false]}} #DR2628_CTOR
+  constexpr foo() requires (A || B) = delete; // expected-note {{candidate function [with A = false, B = false]}}
 };
 
 void f() {
-  foo fooable; // expected-error {{call to deleted}}
-  // expected-note@#DR2628_CTOR {{marked deleted here}}
+  // The FIXME's below should be the expected errors when dr2628 is
+  // fully implemented again.
+  // FIXME-expected-error {{call to deleted}}
+  foo fooable; // expected-error {{ambiguous deduction for template arguments of 'foo'}}
+  // FIXME-expected-note@#DR2628_CTOR {{marked deleted here}}
 }
 
 }