[clang] Non-trivial fixes in C++ DR tests (#179813)

This is a follow-up to #179674, which applies various fixes across C++
DR tests uncovered by `-verify-directives` (#179835
).

Changes here serve double duty. First, they fix actual problems found by
`-verify-directives`, because I've been manually enforcing those rules
manually for quite a while. Second, they show typical problems and
possible solutions when you opt-in a test to use `-verify-directives`.
This PR focuses on interesting cases, as partial diagnostic matches,
which are trivial to fix, are fixed in boring #179674

Changes include:
1. Getting rid of instantiations at the end of TU that emit diagnostics:
either trigger them earlier, or move them to a separate file
2. Reordering of `expected-error` and `expected-note` to match the order
in which corresponding diagnsotics are emitted.
3. Eliminating leftover partial matches of diagnostic text
4. Removing some extension warnings, because C++ DR tests are not
interested in features backported to older language modes.
5. Fix for a hilarious case of CWG413 test, which was checking for a
note from a typo correction that happened in another test.

26 files changed, 712 insertions, 615 deletions

diff --git a/clang/test/CXX/drs/cwg0xx.cpp b/clang/test/CXX/drs/cwg0xx.cpp
index 6d3a3238d4f3..793ef5c7e2fd 100644
--- a/clang/test/CXX/drs/cwg0xx.cpp
+++ b/clang/test/CXX/drs/cwg0xx.cpp
@@ -484,7 +484,7 @@ namespace cwg33 { // cwg33: 9
 
   template<typename T> void t(X::S);
   template<typename T, typename U = void> void u(X::S);
-  // expected-error@-1 0-1 {{default template arguments for a function template are a C++11 extension}}
+  // cxx98-error@-1 {{default template arguments for a function template are a C++11 extension}}
   void templ() { f(t<int>); f(u<int>); }
 
   // Even though v<int> cannot select the first overload, ADL considers it
@@ -1042,16 +1042,16 @@ namespace cwg62 { // cwg62: 2.9
   //   cxx98-note@#cwg62-unnamed {{unnamed type used in template argument was declared here}}
   NoNameForLinkagePtr p1 = get<NoNameForLinkagePtr>();
   // cxx98-error@-1 {{template argument uses unnamed type}}
+  //   cxx98-note@-2 {{while substituting explicitly-specified template arguments into function template 'get'}}
   //   cxx98-note@#cwg62-unnamed {{unnamed type used in template argument was declared here}}
-  //   cxx98-note@-3 {{while substituting explicitly-specified template arguments}}
   NoNameForLinkagePtr p2 = get<const NoNameForLinkagePtr>();
   // cxx98-error@-1 {{template argument uses unnamed type}}
+  //   cxx98-note@-2 {{while substituting explicitly-specified template arguments into function template 'get'}}
   //   cxx98-note@#cwg62-unnamed {{unnamed type used in template argument was declared here}}
-  //   cxx98-note@-3 {{while substituting explicitly-specified template arguments}}
   int n1 = take(noNameForLinkagePtr);
   // cxx98-error@-1 {{template argument uses unnamed type}}
+  //   cxx98-note@-2 {{while substituting deduced template arguments into function template 'take' [with T = NoNameForLinkagePtr]}}
   //   cxx98-note@#cwg62-unnamed {{unnamed type used in template argument was declared here}}
-  //   cxx98-note@-3 {{while substituting deduced template arguments}}
 
   X<Danger> x4;
 
@@ -1378,9 +1378,10 @@ namespace cwg92 { // cwg92: 4 c++17
   // considered in this context. In C++17, we *do* perform an implicit
   // conversion (which performs initialization), and the exception specification
   // is part of the type of the parameter, so this is invalid.
-  template<void() throw()> struct X {}; // since-cxx17-note {{template parameter is declared here}}
+  template<void() throw()> struct X {}; // #cwg92-X
   X<&f> xp;
   // since-cxx17-error@-1 {{value of type 'void (*)() throw(int, float)' is not implicitly convertible to 'void (*)() throw()'}}
+  //   since-cxx17-note@#cwg92-X {{template parameter is declared here}}
 
   template<void() throw(int)> struct Y {};
   // since-cxx17-error@-1 {{ISO C++17 does not allow dynamic exception specifications}}
@@ -1440,33 +1441,7 @@ namespace cwg97 { // cwg97: 2.7
   };
 } // namespace cwg97
 
-namespace cwg98 { // cwg98: 2.7
-  void test(int n) {
-    switch (n) {
-      try { // #cwg98-try
-        case 0:
-        // expected-error@-1 {{cannot jump from switch statement to this case label}}
-        //   expected-note@#cwg98-try {{jump bypasses initialization of try block}}
-        x:
-          throw n;
-      } catch (...) { // #cwg98-catch
-        case 1:
-        // expected-error@-1 {{cannot jump from switch statement to this case label}}
-        //   expected-note@#cwg98-catch {{jump bypasses initialization of catch block}}
-        y:
-          throw n;
-      }
-      case 2:
-        goto x;
-        // expected-error@-1 {{cannot jump from this goto statement to its label}}
-        //   expected-note@#cwg98-try {{jump bypasses initialization of try block}}
-      case 3:
-        goto y;
-        // expected-error@-1 {{cannot jump from this goto statement to its label}}
-        //   expected-note@#cwg98-catch {{jump bypasses initialization of catch block}}
-    }
-  }
-} // namespace cwg98
+// cwg98 is in cwg98.cpp
 
 namespace cwg99 { // cwg99: sup 214
   template<typename T> void f(T&);
diff --git a/clang/test/CXX/drs/cwg10xx.cpp b/clang/test/CXX/drs/cwg10xx.cpp
index c5b96c4ab8ff..f0aaa174d6c0 100644
--- a/clang/test/CXX/drs/cwg10xx.cpp
+++ b/clang/test/CXX/drs/cwg10xx.cpp
@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -std=c++98 %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++11 %s -verify=expected -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++14 %s -verify=expected,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++17 %s -verify=expected,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++20 %s -verify=expected,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++98 %s -verify=expected,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++11 %s -verify=expected,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++14 %s -verify=expected,since-cxx11,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++17 %s -verify=expected,since-cxx11,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 %s -verify=expected,since-cxx11,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx11,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx11,since-cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
 
 namespace std {
   __extension__ typedef __SIZE_TYPE__ size_t;
@@ -41,8 +41,9 @@ namespace cwg1004 { // cwg1004: 5
   // This example (from the standard) is actually ill-formed, because
   // name lookup of "T::template A" names the constructor.
   template<class T, template<class> class U = T::template A> struct Third { };
-  // expected-error@-1 {{is a constructor name}}
-  //   expected-note@#cwg1004-t {{in instantiation of default argument}}
+  // expected-error@-1 {{ISO C++ specifies that qualified reference to 'A' is a constructor name rather than a template name in this context, despite preceding 'typename' keyword}}
+  //   cxx98-note@#cwg1004-t {{in instantiation of default argument for 'Third<A<int> >' required here}}
+  //   since-cxx11-note@#cwg1004-t {{in instantiation of default argument for 'Third<A<int>>' required here}}
   Third<A<int> > t; // #cwg1004-t
 } // namespace cwg1004
 
diff --git a/clang/test/CXX/drs/cwg13xx.cpp b/clang/test/CXX/drs/cwg13xx.cpp
index 0f97c484becd..29d66ffb9241 100644
--- a/clang/test/CXX/drs/cwg13xx.cpp
+++ b/clang/test/CXX/drs/cwg13xx.cpp
@@ -79,47 +79,40 @@ namespace cwg1310 { // cwg1310: 5
     W<int>::W<int> w1b;
     // expected-error@-1 {{qualified reference to 'W' is a constructor name rather than a template name in this context}}
     W<int>::W<int>::X w1bx;
+#if __cplusplus >= 201103L
     typename W<int>::W w2a;
-    // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a type in this context, despite preceding 'typename' keyword}}
-    // cxx98-error@-2 {{'typename' outside of a template is a C++11 extension}}
+    // since-cxx11-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a type in this context, despite preceding 'typename' keyword}}
     typename W<int>::W::X w2ax;
-    // cxx98-error@-1 {{'typename' outside of a template is a C++11 extension}}
     typename W<int>::W<int> w2b;
-    // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'typename' keyword}}
-    // cxx98-error@-2 {{'typename' outside of a template is a C++11 extension}}
+    // since-cxx11-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'typename' keyword}}
     typename W<int>::W<int>::X w2bx;
-    // cxx98-error@-1 {{'typename' outside of a template is a C++11 extension}}
     W<int>::template W<int> w3;
-    // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
-    // cxx98-error@-2 {{'template' keyword outside of a template}}
+    // since-cxx11-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
     W<int>::template W<int>::X w3x;
-    // cxx98-error@-1 {{'template' keyword outside of a template}}
     typename W<int>::template W<int> w4;
-    // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
-    // cxx98-error@-2 {{'template' keyword outside of a template}}
-    // cxx98-error@-3 {{'typename' outside of a template is a C++11 extension}}
+    // since-cxx11-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
     typename W<int>::template W<int>::X w4x;
-    // cxx98-error@-1 {{'template' keyword outside of a template}}
-    // cxx98-error@-2 {{'typename' outside of a template is a C++11 extension}}
+#endif
 
     TT<W<int>::W> tt1;
     // expected-error@-1 {{qualified reference to 'W' is a constructor name rather than a type in this context}}
     TTy<W<int>::W> tt1a;
     // expected-error@-1 {{qualified reference to 'W' is a constructor name rather than a type in this context}}
-    TT<W<int>::template W> tt2;
-    // expected-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
-    // cxx98-error@-2 {{'template' keyword outside of a template}}
     TT<W<int>::WBase> tt3;
     TTy<W<int>::WBase> tt3a;
+#if __cplusplus >= 201103L
+    TT<W<int>::template W> tt2;
+    // since-cxx11-error@-1 {{ISO C++ specifies that qualified reference to 'W' is a constructor name rather than a template name in this context, despite preceding 'template' keyword}}
     TT<W<int>::template WBase> tt4;
-    // cxx98-error@-1 {{'template' keyword outside of a template}}
+#endif
 
     W<int> w;
     (void)w.W::W::n;
     (void)w.W<int>::W::n;
     (void)w.W<int>::W<int>::n;
+#if __cplusplus >= 201103L
     (void)w.W<int>::template W<int>::n;
-    // cxx98-error@-1 {{'template' keyword outside of a template}}
+#endif
   }
 
   template<typename W>
@@ -260,19 +253,18 @@ namespace cwg1330 { // cwg1330: 4 c++11
   static_assert(!noexcept(B<Q>().g()), "");
 #endif
 
+#if __cplusplus <= 201402L
   template<typename T> int f() throw(typename T::error) { return 0; } // #cwg1330-f
-  // expected-error@#cwg1330-f {{type 'int' cannot be used prior to '::' because it has no members}}
+  // cxx98-14-error@#cwg1330-f {{type 'int' cannot be used prior to '::' because it has no members}}
   //   cxx98-note@#cwg1330-f-int {{in instantiation of function template specialization 'cwg1330::f<int>' requested here}}
-  //   since-cxx11-note@#cwg1330-f-int {{in instantiation of exception specification for 'f<int>' requested here}}
+  //   cxx11-14-note@#cwg1330-f-int {{in instantiation of exception specification for 'f<int>' requested here}}
+  // cxx11-14-error@#cwg1330-f {{type 'char' cannot be used prior to '::' because it has no members}}
+  //   cxx11-14-note@#cwg1330-f-char {{in instantiation of exception specification for 'f<char>' requested here}}
+  // cxx11-14-error@#cwg1330-f {{type 'float' cannot be used prior to '::' because it has no members}}
+  //   cxx11-14-note@#cwg1330-f-float {{in instantiation of exception specification for 'f<float>' requested here}}
   // cxx98-14-error@#cwg1330-f {{type 'short' cannot be used prior to '::' because it has no members}}
-  //   cxx98-14-note@#cwg1330-f-short {{in instantiation of function template specialization 'cwg1330::f<short>' requested here}}
   //   cxx11-14-note@#cwg1330-f {{in instantiation of exception specification for 'f<short>' requested here}}
-  // since-cxx11-error@#cwg1330-f {{type 'char' cannot be used prior to '::' because it has no members}}
-  //   since-cxx11-note@#cwg1330-f-char {{in instantiation of exception specification for 'f<char>' requested here}}
-  // since-cxx11-error@#cwg1330-f {{type 'float' cannot be used prior to '::' because it has no members}}
-  //   since-cxx11-note@#cwg1330-f-float {{in instantiation of exception specification for 'f<float>' requested here}}
-  // since-cxx17-error@#cwg1330-f {{ISO C++17 does not allow dynamic exception specifications}}
-  //   since-cxx17-note@#cwg1330-f {{use 'noexcept(false)' instead}}
+  //   cxx98-14-note@#cwg1330-f-short {{in instantiation of function template specialization 'cwg1330::f<short>' requested here}}
 
   // An exception-specification is needed even if the function is only used in
   // an unevaluated operand.
@@ -282,9 +274,7 @@ namespace cwg1330 { // cwg1330: 4 c++11
   bool f3 = noexcept(f<float>()); /// #cwg1330-f-float
 #endif
   template int f<short>(); // #cwg1330-f-short
-  // since-cxx17-error@#cwg1330-f {{type 'short' cannot be used prior to '::' because it has no members}}
-  //   since-cxx17-note@#cwg1330-f {{in instantiation of exception specification for 'f<short>' requested here}}
-  //   since-cxx17-note@#cwg1330-f-short {{in instantiation of function template specialization 'cwg1330::f<short>' requested here}}
+#endif
 
   template<typename T> struct C {
     C() throw(typename T::type); // #cwg1330-C
@@ -358,22 +348,17 @@ namespace cwg1346 { // cwg1346: 3.5
   }
   template void f(); // #cwg1346-f
 
-#if __cplusplus >= 201103L
+#if __cplusplus >= 201402L
   void init_capture() {
     [a(1)] {} ();
-    // cxx11-error@-1 {{initialized lambda captures are a C++14 extension}}
     [b(1, 2)] {} ();
-    // cxx11-error@-1 {{initialized lambda captures are a C++14 extension}}
-    // since-cxx11-error@-2 {{initializer for lambda capture 'b' contains multiple expressions}}
+    // since-cxx14-error@-1 {{initializer for lambda capture 'b' contains multiple expressions}}
     [c({})] {} ();
-    // cxx11-error@-1 {{initialized lambda captures are a C++14 extension}}
-    // since-cxx11-error@-2 {{cannot deduce type for lambda capture 'c' from parenthesized initializer list}}
+    // since-cxx14-error@-1 {{cannot deduce type for lambda capture 'c' from parenthesized initializer list}}
     [d({1})] {} ();
-    // cxx11-error@-1 {{initialized lambda captures are a C++14 extension}}
-    // since-cxx11-error@-2 {{cannot deduce type for lambda capture 'd' from parenthesized initializer list}}
+    // since-cxx14-error@-1 {{cannot deduce type for lambda capture 'd' from parenthesized initializer list}}
     [e({1, 2})] {} ();
-    // cxx11-error@-1 {{initialized lambda captures are a C++14 extension}}
-    // since-cxx11-error@-2 {{cannot deduce type for lambda capture 'e' from parenthesized initializer list}}
+    // since-cxx14-error@-1 {{cannot deduce type for lambda capture 'e' from parenthesized initializer list}}
   }
 #endif
 } // namespace cwg1346
diff --git a/clang/test/CXX/drs/cwg15xx.cpp b/clang/test/CXX/drs/cwg15xx.cpp
index 8e3e49dc42ce..e97584c293cc 100644
--- a/clang/test/CXX/drs/cwg15xx.cpp
+++ b/clang/test/CXX/drs/cwg15xx.cpp
@@ -38,22 +38,40 @@ namespace cwg1512 { // cwg1512: 4
   template<typename A, typename B, typename C> void composite_pointer_type_is_ord() {
     composite_pointer_type_is_base<A, B, C>();
 
-    typedef __typeof(val<A>() < val<B>()) cmp; // #cwg1512-lt
-    // since-cxx17-warning@#cwg1512-lt {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
-    //   since-cxx17-note@#cwg1512-noexcept-1st {{in instantiation of function template specialization 'cwg1512::composite_pointer_type_is_ord<int (*)() noexcept, int (*)(), int (*)()>' requested here}}
-    // since-cxx17-warning@#cwg1512-lt {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
-    //   since-cxx17-note@#cwg1512-noexcept-2nd {{in instantiation of function template specialization 'cwg1512::composite_pointer_type_is_ord<int (*)(), int (*)() noexcept, int (*)()>' requested here}}
+    typedef __typeof(val<A>() < val<B>()) cmp;
     typedef __typeof(val<A>() <= val<B>()) cmp;
-    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
-    // since-cxx17-warning@-2 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
     typedef __typeof(val<A>() > val<B>()) cmp;
-    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
-    // since-cxx17-warning@-2 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
     typedef __typeof(val<A>() >= val<B>()) cmp;
+    typedef bool cmp;
+  }
+
+#if __cplusplus >= 201703L
+  void composite_pointer_type_is_ord_2() {
+    composite_pointer_type_is_base<int (*)() noexcept, int (*)(), int (*)()>();
+
+    typedef __typeof(val<int (*)() noexcept>() < val<int (*)()>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
+    typedef __typeof(val<int (*)() noexcept>() <= val<int (*)()>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
+    typedef __typeof(val<int (*)() noexcept>() > val<int (*)()>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
+    typedef __typeof(val<int (*)() noexcept>() >= val<int (*)()>()) cmp;
     // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)() noexcept' and 'int (*)()')}}
-    // since-cxx17-warning@-2 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
+
+    composite_pointer_type_is_base<int (*)(), int (*)() noexcept, int (*)()>();
+
+    typedef __typeof(val<int (*)()>() < val<int (*)() noexcept>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
+    typedef __typeof(val<int (*)()>() <= val<int (*)() noexcept>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
+    typedef __typeof(val<int (*)()>() > val<int (*)() noexcept>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
+    typedef __typeof(val<int (*)()>() >= val<int (*)() noexcept>()) cmp;
+    // since-cxx17-warning@-1 {{ordered comparison of function pointers ('int (*)()' and 'int (*)() noexcept')}}
+
     typedef bool cmp;
   }
+#endif
 
   template <typename A, typename B, typename C>
   void composite_pointer_type_is_unord(int = 0) {
@@ -100,8 +118,6 @@ namespace cwg1512 { // cwg1512: 4
     // since-cxx20-warning@-1 {{volatile-qualified return type 'volatile int' is deprecated}}
 
 #if __cplusplus >= 201703L
-    composite_pointer_type_is_ord<int (*)() noexcept, int (*)(), int (*)()>(); // #cwg1512-noexcept-1st
-    composite_pointer_type_is_ord<int (*)(), int (*)() noexcept, int (*)()>(); // #cwg1512-noexcept-2nd
     composite_pointer_type_is_unord<int (A::*)() noexcept, int (A::*)(), int (A::*)()>();
     composite_pointer_type_is_unord<int (A::*)(), int (A::*)() noexcept, int (A::*)()>();
     // FIXME: This looks like a standard defect; these should probably all have type 'int (B::*)()'.
@@ -157,15 +173,15 @@ namespace cwg1512 { // cwg1512: 4
     //   since-cxx11-note@#cwg1512-Wrap {{first operand was implicitly converted to type 'std::nullptr_t'}}
     //   since-cxx11-note@#cwg1512-Wrap {{second operand was implicitly converted to type 'int *'}}
     void(Wrap<nullptr_t>() > Wrap<int*>());
-    // since-cxx11-error@-1 {{invalid operands}}
+    // since-cxx11-error@-1 {{invalid operands to binary expression ('Wrap<nullptr_t>' (aka 'Wrap<std::nullptr_t>') and 'Wrap<int *>')}}
     //   since-cxx11-note@#cwg1512-Wrap {{first operand was implicitly converted to type 'std::nullptr_t'}}
     //   since-cxx11-note@#cwg1512-Wrap{{second operand was implicitly converted to type 'int *'}}
     void(Wrap<nullptr_t>() <= Wrap<int*>());
-    // since-cxx11-error@-1 {{invalid operands}}
+    // since-cxx11-error@-1 {{invalid operands to binary expression ('Wrap<nullptr_t>' (aka 'Wrap<std::nullptr_t>') and 'Wrap<int *>')}}
     //   since-cxx11-note@#cwg1512-Wrap {{first operand was implicitly converted to type 'std::nullptr_t'}}
     //   since-cxx11-note@#cwg1512-Wrap {{second operand was implicitly converted to type 'int *'}}
     void(Wrap<nullptr_t>() >= Wrap<int*>());
-    // since-cxx11-error@-1 {{invalid operands}}
+    // since-cxx11-error@-1 {{invalid operands to binary expression ('Wrap<nullptr_t>' (aka 'Wrap<std::nullptr_t>') and 'Wrap<int *>')}}
     //   since-cxx11-note@#cwg1512-Wrap {{first operand was implicitly converted to type 'std::nullptr_t'}}
     //   since-cxx11-note@#cwg1512-Wrap {{second operand was implicitly converted to type 'int *'}}
   }
@@ -309,16 +325,14 @@ namespace std_example {
     //   since-cxx11-note@#cwg1518-x {{passing argument to parameter 't' here}}
   }
 
-  void test() {
-    f<A>(); // #cwg1518-f-A
-    f<B>(); // #cwg1518-f-B
-    f<C>(); // #cwg1518-f-C
-    f<D>(); // #cwg1518-f-D
-    g<A>(); // #cwg1518-g-A
-    g<B>(); // #cwg1518-g-B
-    g<C>(); // #cwg1518-g-C
-    g<D>(); // #cwg1518-g-D
-  }
+  template void f<A>(); // #cwg1518-f-A
+  template void f<B>(); // #cwg1518-f-B
+  template void f<C>(); // #cwg1518-f-C
+  template void f<D>(); // #cwg1518-f-D
+  template void g<A>(); // #cwg1518-g-A
+  template void g<B>(); // #cwg1518-g-B
+  template void g<C>(); // #cwg1518-g-C
+  template void g<D>(); // #cwg1518-g-D
 }
 #endif // __cplusplus >= 201103L
 } // namespace cwg1518
@@ -426,8 +440,8 @@ namespace cwg1573 { // cwg1573: 3.9
   constexpr F f = F(0);
   // since-cxx11-error@-1 {{constexpr variable 'f' must be initialized by a constant expression}}
   //   cxx11-20-note@-2 {{constructor inherited from base class 'C' cannot be used in a constant expression; derived class cannot be implicitly initialized}}
-  //   since-cxx23-note@-3 {{in implicit initialization for inherited constructor of 'F'}}
   //   since-cxx23-note@#cwg1573-F {{non-constexpr constructor 'C' cannot be used in a constant expression}}
+  //   since-cxx23-note@-4 {{in implicit initialization for inherited constructor of 'F'}}
   //   cxx11-20-note@#cwg1573-F {{declared here}}
   //   since-cxx23-note@#cwg1573-C {{declared here}}
 
@@ -564,16 +578,18 @@ namespace cwg1584 { // cwg1584: 7 drafting 2015-05
 // Deducing function types from cv-qualified types
 template<typename T> void f(const T *); // #cwg1584-f
 template<typename T> void g(T *, const T * = 0);
-template<typename T> void h(T *) { T::error; }
-// expected-error@-1 {{type 'void ()' cannot be used prior to '::' because it has no members}}
-//   expected-note@#cwg1584-h {{in instantiation of function template specialization 'cwg1584::h<void ()>' requested here}}
-template<typename T> void h(const T *);
+template<typename T> void h(T *) = delete; // #cwg1584-h-T
+// cxx98-error@-1 {{deleted function definitions are a C++11 extension}}
+template<typename T> void h(const T *);  // #cwg1584-h-const-T
 void i() {
   f(&i);
   // expected-error@-1 {{no matching function for call to 'f'}}
   //   expected-note@#cwg1584-f {{candidate template ignored: could not match 'const T *' against 'void (*)()'}}
   g(&i);
-  h(&i); // #cwg1584-h
+  h(&i);
+  // expected-error@-1 {{call to deleted function 'h'}}
+  //   expected-note@#cwg1584-h-T {{candidate function [with T = void ()] has been explicitly deleted}}
+  //   expected-note@#cwg1584-h-const-T {{candidate template ignored: could not match 'const T *' against 'void (*)()'}}
 }
 
 template<typename T> struct tuple_size {
diff --git a/clang/test/CXX/drs/cwg16xx.cpp b/clang/test/CXX/drs/cwg16xx.cpp
index 1a36aba859e5..efb743871d52 100644
--- a/clang/test/CXX/drs/cwg16xx.cpp
+++ b/clang/test/CXX/drs/cwg16xx.cpp
@@ -266,12 +266,14 @@ namespace cwg1658 { // cwg1658: 5
     struct A { A(A&); };
     struct B : virtual A { virtual void f() = 0; };
     struct C : virtual A { virtual void f(); };
-    struct D : A { virtual void f() = 0; }; // since-cxx23-note {{previous declaration is here}}
+    struct D : A { virtual void f() = 0; }; // #cwg1658-D
 
     struct X {
       friend B::B(const B&) throw();
       friend C::C(C&);
-      friend D::D(D&); // since-cxx23-error {{non-constexpr declaration of 'D' follows constexpr declaration}}
+      friend D::D(D&);
+      // since-cxx23-error@-1 {{non-constexpr declaration of 'D' follows constexpr declaration}}
+      //   since-cxx23-note@#cwg1658-D {{previous declaration is here}}
     };
   }
 
@@ -373,7 +375,6 @@ namespace cwg1687 { // cwg1687: 7
   int *a = To<int*>() + 100.0;
   // expected-error@-1 {{invalid operands to binary expression ('To<int *>' and 'double')}}
   //   expected-note@#cwg1687-op-T {{first operand was implicitly converted to type 'int *'}}
-  //   since-cxx20-note@#cwg1687-op-T {{second operand was implicitly converted to type 'cwg1687::E2'}}
   int *b = To<int*>() + To<double>();
   // expected-error@-1 {{invalid operands to binary expression ('To<int *>' and 'To<double>')}}
   //   expected-note@#cwg1687-op-T {{first operand was implicitly converted to type 'int *'}}
@@ -384,7 +385,8 @@ namespace cwg1687 { // cwg1687: 7
   enum E2 {};
   auto c = To<E1>() <=> To<E2>();
   // since-cxx20-error@-1 {{invalid operands to binary expression ('To<E1>' and 'To<E2>')}}
-  //   since-cxx20-note@#cwg1687-op-T {{operand was implicitly converted to type 'cwg1687::E}}
+  //   since-cxx20-note@#cwg1687-op-T {{first operand was implicitly converted to type 'cwg1687::E1'}}
+  //   since-cxx20-note@#cwg1687-op-T {{second operand was implicitly converted to type 'cwg1687::E2'}}
 #endif
 } // namespace cwg1687
 
@@ -458,13 +460,13 @@ namespace cwg1696 { // cwg1696: 7
     };
 
     struct A2 {
-      A2() = default;
-      // since-cxx14-error@-1 {{reference member 'v' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
-      // since-cxx14-note-re@#cwg1696-A2-b {{in defaulted default constructor for {{.*}} first required here}}
-      // since-cxx14-note@#cwg1696-A2-a {{initializing field 'v' with default member initializer}}
       A2(int v) : v(v) {}
       // since-cxx14-warning@-1 {{binding reference member 'v' to stack allocated parameter 'v'}}
-      // since-cxx14-note@#cwg1696-A2-a {{reference member declared here}}
+      //   since-cxx14-note@#cwg1696-A2-a {{reference member declared here}}
+      A2() = default;
+      // since-cxx14-error@-1 {{reference member 'v' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
+      //   since-cxx14-note-re@#cwg1696-A2-b {{in defaulted default constructor for {{.*}} first required here}}
+      //   since-cxx14-note@#cwg1696-A2-a {{initializing field 'v' with default member initializer}}
       const int &v = 42;  // #cwg1696-A2-a
     };
     A2 a1;    // #cwg1696-A2-b
diff --git a/clang/test/CXX/drs/cwg1736.cpp b/clang/test/CXX/drs/cwg1736.cpp
new file mode 100644
index 000000000000..25b9fcb747ec
--- /dev/null
+++ b/clang/test/CXX/drs/cwg1736.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11
+
+// cxx98-no-diagnostics
+
+namespace cwg1736 { // cwg1736: 3.9
+#if __cplusplus >= 201103L
+struct S {
+  template <class T> S(T t) {
+    struct L : S {
+      using S::S;
+    };
+    typename T::type value;
+    // since-cxx11-error@-1 {{type 'int' cannot be used prior to '::' because it has no members}}
+    //   since-cxx11-note@#cwg1736-l {{in instantiation of function template specialization 'cwg1736::S::S<int>' requested here}}
+    //   since-cxx11-note@#cwg1736-s {{in instantiation of function template specialization 'cwg1736::S::S<cwg1736::Q>' requested here}}
+    L l(value); // #cwg1736-l
+  }
+};
+struct Q { typedef int type; } q;
+S s(q); // #cwg1736-s
+#endif
+} // namespace cwg1736
diff --git a/clang/test/CXX/drs/cwg17xx.cpp b/clang/test/CXX/drs/cwg17xx.cpp
index 8c4f916a606a..cafa21dc17ee 100644
--- a/clang/test/CXX/drs/cwg17xx.cpp
+++ b/clang/test/CXX/drs/cwg17xx.cpp
@@ -98,24 +98,7 @@ static_assert(__is_trivially_copyable(A), "");
 #endif
 } // namespace cwg1734
 
-namespace cwg1736 { // cwg1736: 3.9
-#if __cplusplus >= 201103L
-struct S {
-  template <class T> S(T t) {
-    struct L : S {
-      using S::S;
-    };
-    typename T::type value;
-    // since-cxx11-error@-1 {{type 'int' cannot be used prior to '::' because it has no members}}
-    //   since-cxx11-note@#cwg1736-l {{in instantiation of function template specialization 'cwg1736::S::S<int>' requested here}}
-    //   since-cxx11-note@#cwg1736-s {{in instantiation of function template specialization 'cwg1736::S::S<cwg1736::Q>' requested here}}
-    L l(value); // #cwg1736-l
-  }
-};
-struct Q { typedef int type; } q;
-S s(q); // #cwg1736-s
-#endif
-} // namespace cwg1736
+// cwg1736 is in cwg1736.cpp
 
 namespace cwg1738 { // cwg1738: sup P0136R1
 #if __cplusplus >= 201103L
diff --git a/clang/test/CXX/drs/cwg18xx.cpp b/clang/test/CXX/drs/cwg18xx.cpp
index c0363fa467ea..f8f85611498f 100644
--- a/clang/test/CXX/drs/cwg18xx.cpp
+++ b/clang/test/CXX/drs/cwg18xx.cpp
@@ -213,8 +213,8 @@ namespace cwg1815 { // cwg1815: 20
 
   struct B { int &&r = 0; }; // #cwg1815-B
   // since-cxx14-error@-1 {{reference member 'r' binds to a temporary object whose lifetime would be shorter than the lifetime of the constructed object}}
-  //   since-cxx14-note@#cwg1815-B {{initializing field 'r' with default member initializer}}
   //   since-cxx14-note@#cwg1815-b {{in implicit default constructor for 'cwg1815::B' first required here}}
+  //   since-cxx14-note@#cwg1815-B {{initializing field 'r' with default member initializer}}
   B b; // #cwg1815-b
 
 #if __cplusplus >= 201703L
@@ -584,16 +584,16 @@ void cwg1891() { // cwg1891: 4
   typedef decltype(b) B;
 
   static_assert(!__is_trivially_constructible(A), "");
-  // since-cxx20-error@-1 {{failed}}
+  // since-cxx20-error-re@-1 {{static assertion failed due to requirement '!__is_trivially_constructible((lambda at {{.+}}))':}}
   static_assert(!__is_trivially_constructible(B), "");
 
   // C++20 allows default construction for non-capturing lambdas (P0624R2).
   A x;
-  // cxx11-17-error@-1 {{no matching constructor for initialization of 'A' (aka '(lambda at}}
+  // cxx11-17-error-re@-1 {{no matching constructor for initialization of 'A' (aka '(lambda at {{.+}})')}}
   //   cxx11-17-note@#cwg1891-a {{candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 0 were provided}}
   //   cxx11-17-note@#cwg1891-a {{candidate constructor (the implicit move constructor) not viable: requires 1 argument, but 0 were provided}}
   B y;
-  // since-cxx11-error@-1 {{no matching constructor for initialization of 'B' (aka '(lambda at}}
+  // since-cxx11-error-re@-1 {{no matching constructor for initialization of 'B' (aka '(lambda at {{.+}})')}}
   //   since-cxx11-note@#cwg1891-b {{candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 0 were provided}}
   //   since-cxx11-note@#cwg1891-b {{candidate constructor (the implicit move constructor) not viable: requires 1 argument, but 0 were provided}}
 
diff --git a/clang/test/CXX/drs/cwg1xx.cpp b/clang/test/CXX/drs/cwg1xx.cpp
index 066a429ea1c5..359a194b1fdb 100644
--- a/clang/test/CXX/drs/cwg1xx.cpp
+++ b/clang/test/CXX/drs/cwg1xx.cpp
@@ -213,8 +213,7 @@ namespace cwg115 { // cwg115: 3.0
     &f;
     // expected-error@-1 {{reference to overloaded function could not be resolved; did you mean to call it?}}
     //   expected-note@#cwg115-f {{possible target for call}}
-    &f<int>;
-    // expected-warning@-1 {{expression result unused}}
+    (void)&f<int>;
     &g<int>;
     // expected-error@-1 {{reference to overloaded function could not be resolved; did you mean to call it?}}
     //   expected-note@#cwg115-g-int {{possible target for call}}
@@ -242,8 +241,7 @@ namespace cwg115 { // cwg115: 3.0
 
     &s.f;
     // expected-error@-1 {{cannot create a non-constant pointer to member function}}
-    &s.f<int>;
-    // expected-warning@-1 {{expression result unused}}
+    (void)&s.f<int>;
     &s.g<int>;
     // expected-error@-1 {{cannot create a non-constant pointer to member function}}
   }
@@ -269,8 +267,7 @@ namespace cwg115 { // cwg115: 3.0
 
     &s.f;
     // expected-error@-1 {{cannot create a non-constant pointer to member function}}
-    &s.f<int>;
-    // expected-warning@-1 {{expression result unused}}
+    (void)&s.f<int>;
     &s.g<int>;
     // expected-error@-1 {{cannot create a non-constant pointer to member function}}
   }
@@ -290,8 +287,7 @@ namespace cwg115 { // cwg115: 3.0
     &with_default;
     // since-cxx11-error@-1 {{reference to overloaded function could not be resolved; did you mean to call it?}}
     //   since-cxx11-note@#cwg115-with-default {{possible target for call}}
-    &with_default<>;
-    // since-cxx11-warning@-1 {{expression result unused}}
+    (void)&with_default<>;
   }
 #endif
 } // namespace cwg115
@@ -467,15 +463,17 @@ namespace cwg127 { // cwg127: 2.9
   template<typename T> struct A {
     A() { throw 0; }
     void *operator new(size_t, const char * = 0);
-    void operator delete(void *, const char *) { T::error; } // #cwg127-delete-const-char
-    // expected-error@#cwg127-delete-const-char {{type 'void' cannot be used prior to '::' because it has no members}}
-    //   expected-note@#cwg127-p {{in instantiation of member function 'cwg127::A<void>::operator delete' requested here}}
-    // expected-error@#cwg127-delete-const-char {{type 'int' cannot be used prior to '::' because it has no members}}
-    //   expected-note@#cwg127-q {{in instantiation of member function 'cwg127::A<int>::operator delete' requested here}}
-    void operator delete(void *) { T::error; }
+    void operator delete(void *, const char *) = delete; // #cwg127-delete-char
+    // cxx98-error@-1 {{deleted function definitions are a C++11 extension}}
+    void operator delete(void *) = delete;
+    // cxx98-error@-1 {{deleted function definitions are a C++11 extension}}
   };
-  A<void> *p = new A<void>; // #cwg127-p
-  A<int> *q = new ("") A<int>; // #cwg127-q
+  A<void> *p = new A<void>;
+  // expected-error@-1 {{attempt to use a deleted function}}
+  //   expected-note@#cwg127-delete-char {{'operator delete' has been explicitly marked deleted here}}
+  A<int> *q = new ("") A<int>;
+  // expected-error@-1 {{attempt to use a deleted function}}
+  //   expected-note@#cwg127-delete-char {{'operator delete' has been explicitly marked deleted here}}
 } // namespace cwg127
 
 namespace cwg128 { // cwg128: 2.7
@@ -706,7 +704,8 @@ namespace cwg141 { // cwg141: 3.1
     // FIXME: we issue a useful diagnostic first, then some bogus ones.
     b.f<int>();
     // expected-error@-1 {{no member named 'f' in 'cwg141::B'}}
-    // expected-error@-2 +{{}}
+    // expected-error-re@-2 {{{{.*}}}}
+    // expected-error-re@-3 {{{{.*}}}}
     (void)b.S<int>::n;
   }
   template<typename T> struct C {
@@ -1253,9 +1252,11 @@ namespace cwg180 { // cwg180: 2.8
 namespace cwg181 { // cwg181: 2.7
   namespace X {
     template <template X<class T> > struct A { };
-    // expected-error@-1 +{{}}
+    // expected-error@-1 {{expected '<' after 'template'}}
+    // expected-error@-2 {{expected unqualified-id}}
     template <template X<class T> > void f(A<X>) { }
-    // expected-error@-1 +{{}}
+    // expected-error@-1 {{expected '<' after 'template'}}
+    // expected-error@-2 {{expected unqualified-id}}
   }
 
   namespace Y {
@@ -1426,7 +1427,7 @@ namespace cwg197 { // cwg197: 2.7
     char &a = f(1);
     char &b = f(T(1));
     // expected-error@-1 {{non-const lvalue reference to type 'char' cannot bind to a value of unrelated type 'int'}}
-    //   expected-note@#cwg197-g-e-call {{in instantiation of function template specialization 'cwg197::g<cwg197::E>' requested here}}
+    //   expected-note@#cwg197-g-E {{in instantiation of function template specialization 'cwg197::g<cwg197::E>' requested here}}
     char &c = f(t);
     // expected-error@-1 {{non-const lvalue reference to type 'char' cannot bind to a value of unrelated type 'int'}}
   }
@@ -1436,11 +1437,9 @@ namespace cwg197 { // cwg197: 2.7
   enum E { e };
   int &f(E);
 
-  void h() {
-    g('a');
-    g(2);
-    g(e); // #cwg197-g-e-call
-  }
+template void g<char>(char);
+template void g<int>(int);
+template void g<E>(E); // #cwg197-g-E
 } // namespace cwg197
 
 namespace cwg198 { // cwg198: 2.9
diff --git a/clang/test/CXX/drs/cwg2026.cpp b/clang/test/CXX/drs/cwg2026.cpp
new file mode 100644
index 000000000000..23469f999b77
--- /dev/null
+++ b/clang/test/CXX/drs/cwg2026.cpp
@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,cxx11
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,since-cxx14
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,since-cxx14
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,since-cxx14,since-cxx20
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,since-cxx14,since-cxx20
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx11,since-cxx14,since-cxx20
+
+namespace cwg2026 { // cwg2026: 11
+  template<int> struct X {};
+
+  const int a = a + 1; // #cwg2026-a
+  // expected-warning@-1 {{variable 'a' is uninitialized when used within its own initialization}}
+  X<a> xa; // #cwg2026-xa
+  // cxx98-error@-1 {{non-type template argument of type 'int' is not an integral constant expression}}
+  //   cxx98-note@-2 {{initializer of 'a' is not a constant expression}}
+  //   cxx98-note@#cwg2026-a {{declared here}}
+  // since-cxx11-error@#cwg2026-xa {{non-type template argument is not a constant expression}}
+  //   since-cxx11-note@#cwg2026-xa {{initializer of 'a' is not a constant expression}}
+  //   since-cxx11-note@#cwg2026-a {{declared here}}
+
+#if __cplusplus >= 201103L
+  constexpr int b = b;
+  // since-cxx11-error@-1 {{constexpr variable 'b' must be initialized by a constant expression}}
+  //   since-cxx11-note@-2 {{read of object outside its lifetime is not allowed in a constant expression}}
+  [[clang::require_constant_initialization]] int c = c;
+  // since-cxx11-error@-1 {{variable does not have a constant initializer}}
+  //   since-cxx11-note@-2 {{required by 'require_constant_initialization' attribute here}}
+  //   cxx11-note@-3 {{read of non-const variable 'c' is not allowed in a constant expression}}
+  //   cxx11-note@-4 {{declared here}}
+  //   since-cxx14-note@-5 {{read of object outside its lifetime is not allowed in a constant expression}}
+#endif
+
+#if __cplusplus >= 202002L
+  constinit int d = d;
+  // since-cxx20-error@-1 {{variable does not have a constant initializer}}
+  //   since-cxx20-note@-2 {{required by 'constinit' specifier here}}
+  //   since-cxx20-note@-3 {{read of object outside its lifetime is not allowed in a constant expression}}
+#endif
+
+  void f() {
+    static const int e = e + 1; // #cwg2026-e
+    // expected-warning@-1 {{static variable 'e' is suspiciously used within its own initialization}}
+    X<e> xe; // #cwg2026-xe
+    // cxx98-error@-1 {{non-type template argument of type 'int' is not an integral constant expression}}
+    //   cxx98-note@-2 {{initializer of 'e' is not a constant expression}}
+    //   cxx98-note@#cwg2026-e {{declared here}}
+    // since-cxx11-error@#cwg2026-xe {{non-type template argument is not a constant expression}}
+    //   since-cxx11-note@#cwg2026-xe {{initializer of 'e' is not a constant expression}}
+    //   since-cxx11-note@#cwg2026-e {{declared here}}
+
+#if __cplusplus >= 201103L
+    static constexpr int f = f;
+    // since-cxx11-error@-1 {{constexpr variable 'f' must be initialized by a constant expression}}
+    //   since-cxx11-note@-2 {{read of object outside its lifetime is not allowed in a constant expression}}
+    [[clang::require_constant_initialization]] static int g = g;
+    // since-cxx11-error@-1 {{variable does not have a constant initializer}}
+    //   since-cxx11-note@-2 {{required by 'require_constant_initialization' attribute here}}
+    //   cxx11-note@-3 {{read of non-const variable 'g' is not allowed in a constant expression}}
+    //   cxx11-note@-4 {{declared here}}
+    //   since-cxx14-note@-5 {{read of object outside its lifetime is not allowed in a constant expression}}
+#endif
+
+#if __cplusplus >= 202002L
+    static constinit int h = h;
+    // since-cxx20-error@-1 {{variable does not have a constant initializer}}
+    //   since-cxx20-note@-2 {{required by 'constinit' specifier here}}
+    //   since-cxx20-note@-3 {{read of object outside its lifetime is not allowed in a constant expression}}
+#endif
+  }
+} // namespace cwg2026
diff --git a/clang/test/CXX/drs/cwg20xx.cpp b/clang/test/CXX/drs/cwg20xx.cpp
index 339d4d83c47e..6b120844a606 100644
--- a/clang/test/CXX/drs/cwg20xx.cpp
+++ b/clang/test/CXX/drs/cwg20xx.cpp
@@ -25,70 +25,7 @@ int b = __builtin_addressof(b2)->foo;
 } // namespace cwg2007
 
 // cwg2009: na
-
-namespace cwg2026 { // cwg2026: 11
-  template<int> struct X {};
-
-  const int a = a + 1; // #cwg2026-a
-  // expected-warning@-1 {{variable 'a' is uninitialized when used within its own initialization}}
-  X<a> xa; // #cwg2026-xa
-  // cxx98-error@-1 {{non-type template argument of type 'int' is not an integral constant expression}}
-  //   cxx98-note@-2 {{initializer of 'a' is not a constant expression}}
-  //   cxx98-note@#cwg2026-a {{declared here}}
-  // since-cxx11-error@#cwg2026-xa {{non-type template argument is not a constant expression}}
-  //   since-cxx11-note@#cwg2026-xa {{initializer of 'a' is not a constant expression}}
-  //   since-cxx11-note@#cwg2026-a {{declared here}}
-
-#if __cplusplus >= 201103L
-  constexpr int b = b;
-  // since-cxx11-error@-1 {{constexpr variable 'b' must be initialized by a constant expression}}
-  //   since-cxx11-note@-2 {{read of object outside its lifetime is not allowed in a constant expression}}
-  [[clang::require_constant_initialization]] int c = c;
-  // since-cxx11-error@-1 {{variable does not have a constant initializer}}
-  //   since-cxx11-note@-2 {{required by 'require_constant_initialization' attribute here}}
-  //   cxx11-note@-3 {{read of non-const variable 'c' is not allowed in a constant expression}}
-  //   cxx11-note@-4 {{declared here}}
-  //   since-cxx14-note@-5 {{read of object outside its lifetime is not allowed in a constant expression}}
-#endif
-
-#if __cplusplus >= 202002L
-  constinit int d = d;
-  // since-cxx20-error@-1 {{variable does not have a constant initializer}}
-  //   since-cxx20-note@-2 {{required by 'constinit' specifier here}}
-  //   since-cxx20-note@-3 {{read of object outside its lifetime is not allowed in a constant expression}}
-#endif
-
-  void f() {
-    static const int e = e + 1; // #cwg2026-e
-    // expected-warning@-1 {{static variable 'e' is suspiciously used within its own initialization}}
-    X<e> xe; // #cwg2026-xe
-    // cxx98-error@-1 {{non-type template argument of type 'int' is not an integral constant expression}}
-    //   cxx98-note@-2 {{initializer of 'e' is not a constant expression}}
-    //   cxx98-note@#cwg2026-e {{declared here}}
-    // since-cxx11-error@#cwg2026-xe {{non-type template argument is not a constant expression}}
-    //   since-cxx11-note@#cwg2026-xe {{initializer of 'e' is not a constant expression}}
-    //   since-cxx11-note@#cwg2026-e {{declared here}}
-
-#if __cplusplus >= 201103L
-    static constexpr int f = f;
-    // since-cxx11-error@-1 {{constexpr variable 'f' must be initialized by a constant expression}}
-    //   since-cxx11-note@-2 {{read of object outside its lifetime is not allowed in a constant expression}}
-    [[clang::require_constant_initialization]] static int g = g;
-    // since-cxx11-error@-1 {{variable does not have a constant initializer}}
-    //   since-cxx11-note@-2 {{required by 'require_constant_initialization' attribute here}}
-    //   cxx11-note@-3 {{read of non-const variable 'g' is not allowed in a constant expression}}
-    //   cxx11-note@-4 {{declared here}}
-    //   since-cxx14-note@-5 {{read of object outside its lifetime is not allowed in a constant expression}}
-#endif
-
-#if __cplusplus >= 202002L
-    static constinit int h = h;
-    // since-cxx20-error@-1 {{variable does not have a constant initializer}}
-    //   since-cxx20-note@-2 {{required by 'constinit' specifier here}}
-    //   since-cxx20-note@-3 {{read of object outside its lifetime is not allowed in a constant expression}}
-#endif
-  }
-} // namespace cwg2026
+// cwg2026 is in cwg2026.cpp
 
 namespace cwg2049 { // cwg2049: 18
 #if __cplusplus >= 202302L
@@ -315,39 +252,33 @@ namespace cwg2083 { // cwg2083: partial
       void f() {
         // FIXME: We emit more errors than we should be. They are explicitly
         // marked below.
-        a.x;
-        // expected-warning@-1 {{expression result unused}}
-        // expected-error@-2 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
+        (void)a.x;
+        // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
-        a.*&A::x;
-        // expected-warning@-1 {{expression result unused}}
-        // expected-error@-2 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
+        (void)(a.*&A::x);
+        // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
-        true ? a.x : a.y; // #cwg2083-ternary
-        // expected-warning@-1 {{expression result unused}}
-        // expected-error@#cwg2083-ternary {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
+        (void)(true ? a.x : a.y);
+        // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
-        // expected-error@#cwg2083-ternary {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
+        // expected-error@-3 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
         (void)a.x;
         // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
-        a.x, discarded_lval();
-        // expected-warning@-1 {{left operand of comma operator has no effect}}
-        // expected-error@-2 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
+        (void)a.x, discarded_lval();
+        // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}} FIXME
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
 
         // 'volatile' qualifier triggers an lvalue-to-rvalue conversion.
-        a.z;
-        // cxx98-warning@-1 {{expression result unused; assign into a variable to force a volatile load}}
-        // expected-error@-2 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}}
+        int i = a.z;
+        // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg2083::discarded_lval'}}
         //   expected-note@#cwg2083-a-3 {{'a' declared here}}
 
         // References always get "loaded" to determine what they reference,
         // even if the result is discarded.
-        r;
-        // expected-warning@-1 {{expression result unused}}
-        // expected-error@-2 {{reference to local variable 'r' declared in enclosing function 'cwg2083::discarded_lval'}}
+        (void)r;
+        // expected-error@-1 {{reference to local variable 'r' declared in enclosing function 'cwg2083::discarded_lval'}}
         //   expected-note@#cwg2083-r {{'r' declared here}}
       }
     };
diff --git a/clang/test/CXX/drs/cwg2406.cpp b/clang/test/CXX/drs/cwg2406.cpp
new file mode 100644
index 000000000000..03cd31b4e844
--- /dev/null
+++ b/clang/test/CXX/drs/cwg2406.cpp
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-14
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-14
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-14
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx17
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx17
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx17
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx17
+
+// cxx98-14-no-diagnostics
+
+namespace cwg2406 { // cwg2406: 5
+#if __cplusplus >= 201703L
+void fallthrough(int n) {
+  void g(), h(), i();
+  switch (n) {
+  case 1:
+  case 2:
+    g();
+    [[fallthrough]];
+  case 3: // warning on fallthrough discouraged
+    do {
+      [[fallthrough]];
+      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
+    } while (false);
+  case 6:
+    do {
+      [[fallthrough]];
+      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
+    } while (n);
+  case 7:
+    while (false) {
+      [[fallthrough]];
+      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
+    }
+  case 5:
+    h();
+  case 4: // implementation may warn on fallthrough
+    i();
+    [[fallthrough]];
+    // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
+  }
+}
+#endif
+} // namespace cwg2406
diff --git a/clang/test/CXX/drs/cwg24xx.cpp b/clang/test/CXX/drs/cwg24xx.cpp
index c499a2dfcccb..ec3b29ac7a59 100644
--- a/clang/test/CXX/drs/cwg24xx.cpp
+++ b/clang/test/CXX/drs/cwg24xx.cpp
@@ -6,40 +6,7 @@
 // RUN: %clang_cc1 -std=c++23 -pedantic-errors %s -verify=expected,since-cxx20,since-cxx17
 // RUN: %clang_cc1 -std=c++2c -pedantic-errors %s -verify=expected,since-cxx20,since-cxx17
 
-namespace cwg2406 { // cwg2406: 5
-#if __cplusplus >= 201703L
-void fallthrough(int n) {
-  void g(), h(), i();
-  switch (n) {
-  case 1:
-  case 2:
-    g();
-    [[fallthrough]];
-  case 3: // warning on fallthrough discouraged
-    do {
-      [[fallthrough]];
-      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
-    } while (false);
-  case 6:
-    do {
-      [[fallthrough]];
-      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
-    } while (n);
-  case 7:
-    while (false) {
-      [[fallthrough]];
-      // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
-    }
-  case 5:
-    h();
-  case 4: // implementation may warn on fallthrough
-    i();
-    [[fallthrough]];
-    // since-cxx17-error@-1 {{fallthrough annotation does not directly precede switch label}}
-  }
-}
-#endif
-} // namespace cwg2406
+// cwg2406 is in cwg2406.cpp
 
 namespace cwg2428 { // cwg2428: 19
 #if __cplusplus >= 202002L
diff --git a/clang/test/CXX/drs/cwg25xx.cpp b/clang/test/CXX/drs/cwg25xx.cpp
index 0e0fc735c684..ea79fe16a4fe 100644
--- a/clang/test/CXX/drs/cwg25xx.cpp
+++ b/clang/test/CXX/drs/cwg25xx.cpp
@@ -61,20 +61,17 @@ void f(T t) {
   // cxx11-14-error@-1 {{constexpr if is a C++17 extension}}
     static_assert(false, "must be int-sized");
     // since-cxx11-error@-1 {{static assertion failed: must be int-sized}}
-    //   since-cxx11-note@#cwg2518-f-c {{in instantiation of function template specialization 'cwg2518::f<char>' requested here}}
+    //   since-cxx11-note@#cwg2518-f-char {{in instantiation of function template specialization 'cwg2518::f<char>' requested here}}
   }
 }
 
-void g(char c) {
-  f(0);
-  f(c); // #cwg2518-f-c
-}
+template void f(int);
+template void f(char);  // #cwg2518-f-char
 
 template <typename Ty>
 struct S {
-  static_assert(false);
-  // cxx11-14-error@-1 {{'static_assert' with no message is a C++17 extension}}
-  // since-cxx11-error@-2 {{static assertion failed}}
+  static_assert(false, "");
+  // since-cxx11-error@-1 {{static assertion failed:}}
   //   since-cxx11-note@#cwg2518-S-double {{in instantiation of template class 'cwg2518::S<double>' requested here}}
 };
 
@@ -117,14 +114,14 @@ long double operator"" _RESERVED(long double);
 
 namespace cwg2547 { // cwg2547: 20
 #if __cplusplus >= 202302L
-struct S;
-// since-cxx23-note@-1 {{forward declaration of 'cwg2547::S'}}
-// since-cxx23-note@-2 {{forward declaration of 'cwg2547::S'}}
-// since-cxx23-note@-3 {{forward declaration of 'cwg2547::S'}}
+struct S; // #cwg2547-S
 bool operator==(S, S) = default;  // error: S is not complete
 // since-cxx23-error@-1 {{variable has incomplete type 'S'}}
-// since-cxx23-error@-2 {{variable has incomplete type 'S'}}
-// since-cxx23-error@-3 {{equality comparison operator is not a friend of incomplete class 'cwg2547::S'}}
+//   since-cxx23-note@#cwg2547-S {{forward declaration of 'cwg2547::S'}}
+// since-cxx23-error@-3 {{variable has incomplete type 'S'}}
+//   since-cxx23-note@#cwg2547-S {{forward declaration of 'cwg2547::S'}}
+// since-cxx23-error@-5 {{equality comparison operator is not a friend of incomplete class 'cwg2547::S'}}
+//   since-cxx23-note@#cwg2547-S {{forward declaration of 'cwg2547::S'}}
 struct S {
   friend bool operator==(S, const S&) = default; // error: parameters of different types
   // since-cxx23-error@-1 {{parameters for defaulted equality comparison operator must have the same type (found 'S' vs 'const S &')}}
diff --git a/clang/test/CXX/drs/cwg2881.cpp b/clang/test/CXX/drs/cwg2881.cpp
new file mode 100644
index 000000000000..0a04a486d78b
--- /dev/null
+++ b/clang/test/CXX/drs/cwg2881.cpp
@@ -0,0 +1,147 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-20
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-20
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-20
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-20
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,cxx98-20
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx23
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify=expected,since-cxx23
+
+// cxx98-20-no-diagnostics
+
+namespace cwg2881 { // cwg2881: 19
+#if __cplusplus >= 202302L
+template <typename T> struct A : T {};
+template <typename T> struct B : T {};
+template <typename T> struct C : virtual T { C(T t) : T(t) {} };
+template <typename T> struct D : virtual T { D(T t) : T(t) {} };
+
+template <typename Ts>
+struct O1 : A<Ts>, B<Ts> {
+  using A<Ts>::operator();
+  using B<Ts>::operator();
+};
+
+template <typename Ts> struct O2 : protected Ts { // #cwg2881-O2
+  using Ts::operator();
+  O2(Ts ts) : Ts(ts) {}
+};
+
+template <typename Ts> struct O3 : private Ts { // #cwg2881-O3
+  using Ts::operator();
+  O3(Ts ts) : Ts(ts) {}
+};
+
+// Not ambiguous because of virtual inheritance.
+template <typename Ts>
+struct O4 : C<Ts>, D<Ts> {
+  using C<Ts>::operator();
+  using D<Ts>::operator();
+  O4(Ts t) : Ts(t), C<Ts>(t), D<Ts>(t) {}
+};
+
+// This still has a public path to the lambda, and it's also not
+// ambiguous because of virtual inheritance.
+template <typename Ts>
+struct O5 : private C<Ts>, D<Ts> {
+  using C<Ts>::operator();
+  using D<Ts>::operator();
+  O5(Ts t) : Ts(t), C<Ts>(t), D<Ts>(t) {}
+};
+
+// This is only invalid if we call T's call operator.
+template <typename T, typename U>
+struct O6 : private T, U { // #cwg2881-O6
+  using T::operator();
+  using U::operator();
+  O6(T t, U u) : T(t), U(u) {}
+};
+
+void f() {
+  int x;
+  auto L1 = [=](this auto&& self) { (void) &x; };
+  auto L2 = [&](this auto&& self) { (void) &x; };
+  O1<decltype(L1)>{L1, L1}();
+  /* since-cxx23-error-re@-1 {{lambda '(lambda at {{.+}})' is inaccessible due to ambiguity:
+    struct cwg2881::O1<class (lambda at {{.+}})> -> A<class (lambda at {{.+}})> -> class (lambda at {{.+}})
+    struct cwg2881::O1<class (lambda at {{.+}})> -> B<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
+  O1<decltype(L2)>{L2, L2}();
+  /* since-cxx23-error-re@-1 {{lambda '(lambda at {{.+}})' is inaccessible due to ambiguity:
+    struct cwg2881::O1<class (lambda at {{.+}})> -> A<class (lambda at {{.+}})> -> class (lambda at {{.+}})
+    struct cwg2881::O1<class (lambda at {{.+}})> -> B<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
+  O2{L1}();
+  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O2<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
+  //   since-cxx23-note@#cwg2881-O2 {{declared protected here}}
+  O3{L1}();
+  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O3<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
+  //   since-cxx23-note@#cwg2881-O3 {{declared private here}}
+  O4{L1}();
+  O5{L1}();
+  O6 o{L1, L2};
+  o.decltype(L1)::operator()();
+  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O6<(lambda at {{.+}}), (lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
+  //   since-cxx23-note@#cwg2881-O6 {{declared private here}}
+  o.decltype(L1)::operator()(); // No error here because we've already diagnosed this method.
+  o.decltype(L2)::operator()();
+}
+
+void f2() {
+  int x = 0;
+  auto lambda = [x] (this auto self) { return x; };
+  using Lambda = decltype(lambda);
+  struct D : private Lambda { // #cwg2881-D
+    D(Lambda l) : Lambda(l) {}
+    using Lambda::operator();
+    friend Lambda;
+  } d(lambda);
+  d();
+  // since-cxx23-error@-1 {{invalid explicit object parameter type 'D' in lambda with capture; the type must derive publicly from the lambda}}
+  //   since-cxx23-note@#cwg2881-D {{declared private here}}
+}
+
+template <typename L>
+struct Private : private L {
+  using L::operator();
+  Private(L l) : L(l) {}
+};
+
+template<typename T>
+struct Indirect : T {
+  using T::operator();
+};
+
+template<typename T>
+struct Ambiguous : Indirect<T>, T {
+/* since-cxx23-warning-re@-1 {{direct base '(lambda at {{.+}})' is inaccessible due to ambiguity:
+    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> Indirect<class (lambda at {{.+}})> -> class (lambda at {{.+}})
+    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
+//   since-cxx23-note-re@#cwg2881-f4 {{in instantiation of template class 'cwg2881::Ambiguous<(lambda at {{.+}})>' requested here}}
+//   since-cxx34-note-re@#cwg2881-f4-call {{while substituting deduced template arguments into function template 'f4' [with L = (lambda at {{.+}})]}}
+  using Indirect<T>::operator();
+};
+
+template <typename L>
+constexpr auto f3(L l) -> decltype(Private<L>{l}()) { return l(); } // #cwg2881-f3
+
+template <typename L>
+constexpr auto f4(L l) -> decltype(Ambiguous<L>{{l}, l}()) { return l(); } // #cwg2881-f4
+
+template<typename T>
+concept is_callable = requires(T t) { { t() }; };
+
+void g() {
+  int x = 0;
+  auto lambda = [x](this auto self) {};
+  f3(lambda);
+  // since-cxx23-error@-1 {{no matching function for call to 'f3'}}
+  //   since-cxx23-note-re@#cwg2881-f3 {{candidate template ignored: substitution failure [with L = (lambda at {{.+}})]: invalid explicit object parameter type 'cwg2881::Private<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
+  f4(lambda); // #cwg2881-f4-call
+  // expected-error@-1 {{no matching function for call to 'f4'}}
+  //   expected-note-re@-2 {{while substituting deduced template arguments into function template 'f4' [with L = (lambda at {{.+}})]}}
+  /*   expected-note-re@#cwg2881-f4 {{candidate template ignored: substitution failure [with L = (lambda at {{.+}})]: lambda '(lambda at {{.+}})' is inaccessible due to ambiguity:
+    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> Indirect<class (lambda at {{.+}})> -> class (lambda at {{.+}})
+    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
+  static_assert(!is_callable<Private<decltype(lambda)>>);
+  static_assert(!is_callable<Ambiguous<decltype(lambda)>>);
+}
+#endif
+} // namespace cwg2881
diff --git a/clang/test/CXX/drs/cwg28xx.cpp b/clang/test/CXX/drs/cwg28xx.cpp
index d0ee191ef23d..6d247bb9abe0 100644
--- a/clang/test/CXX/drs/cwg28xx.cpp
+++ b/clang/test/CXX/drs/cwg28xx.cpp
@@ -191,143 +191,7 @@ void g() {
 #endif
 } // namespace cwg2877
 
-namespace cwg2881 { // cwg2881: 19
-#if __cplusplus >= 202302L
-template <typename T> struct A : T {};
-template <typename T> struct B : T {};
-template <typename T> struct C : virtual T { C(T t) : T(t) {} };
-template <typename T> struct D : virtual T { D(T t) : T(t) {} };
-
-template <typename Ts>
-struct O1 : A<Ts>, B<Ts> {
-  using A<Ts>::operator();
-  using B<Ts>::operator();
-};
-
-template <typename Ts> struct O2 : protected Ts { // #cwg2881-O2
-  using Ts::operator();
-  O2(Ts ts) : Ts(ts) {}
-};
-
-template <typename Ts> struct O3 : private Ts { // #cwg2881-O3
-  using Ts::operator();
-  O3(Ts ts) : Ts(ts) {}
-};
-
-// Not ambiguous because of virtual inheritance.
-template <typename Ts>
-struct O4 : C<Ts>, D<Ts> {
-  using C<Ts>::operator();
-  using D<Ts>::operator();
-  O4(Ts t) : Ts(t), C<Ts>(t), D<Ts>(t) {}
-};
-
-// This still has a public path to the lambda, and it's also not
-// ambiguous because of virtual inheritance.
-template <typename Ts>
-struct O5 : private C<Ts>, D<Ts> {
-  using C<Ts>::operator();
-  using D<Ts>::operator();
-  O5(Ts t) : Ts(t), C<Ts>(t), D<Ts>(t) {}
-};
-
-// This is only invalid if we call T's call operator.
-template <typename T, typename U>
-struct O6 : private T, U { // #cwg2881-O6
-  using T::operator();
-  using U::operator();
-  O6(T t, U u) : T(t), U(u) {}
-};
-
-void f() {
-  int x;
-  auto L1 = [=](this auto&& self) { (void) &x; };
-  auto L2 = [&](this auto&& self) { (void) &x; };
-  O1<decltype(L1)>{L1, L1}();
-  /* since-cxx23-error-re@-1 {{inaccessible due to ambiguity:
-    struct cwg2881::O1<class (lambda at {{.+}})> -> A<class (lambda at {{.+}})> -> class (lambda at {{.+}})
-    struct cwg2881::O1<class (lambda at {{.+}})> -> B<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
-  O1<decltype(L2)>{L2, L2}();
-  /* since-cxx23-error-re@-1 {{inaccessible due to ambiguity:
-    struct cwg2881::O1<class (lambda at {{.+}})> -> A<class (lambda at {{.+}})> -> class (lambda at {{.+}})
-    struct cwg2881::O1<class (lambda at {{.+}})> -> B<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
-  O2{L1}();
-  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O2<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
-  //   since-cxx23-note@#cwg2881-O2 {{declared protected here}}
-  O3{L1}();
-  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O3<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
-  //   since-cxx23-note@#cwg2881-O3 {{declared private here}}
-  O4{L1}();
-  O5{L1}();
-  O6 o{L1, L2};
-  o.decltype(L1)::operator()();
-  // since-cxx23-error-re@-1 {{invalid explicit object parameter type 'cwg2881::O6<(lambda at {{.+}}), (lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
-  //   since-cxx23-note@#cwg2881-O6 {{declared private here}}
-  o.decltype(L1)::operator()(); // No error here because we've already diagnosed this method.
-  o.decltype(L2)::operator()();
-}
-
-void f2() {
-  int x = 0;
-  auto lambda = [x] (this auto self) { return x; };
-  using Lambda = decltype(lambda);
-  struct D : private Lambda { // #cwg2881-D
-    D(Lambda l) : Lambda(l) {}
-    using Lambda::operator();
-    friend Lambda;
-  } d(lambda);
-  d();
-  // since-cxx23-error@-1 {{invalid explicit object parameter type 'D' in lambda with capture; the type must derive publicly from the lambda}}
-  //   since-cxx23-note@#cwg2881-D {{declared private here}}
-}
-
-template <typename L>
-struct Private : private L {
-  using L::operator();
-  Private(L l) : L(l) {}
-};
-
-template<typename T>
-struct Indirect : T {
-  using T::operator();
-};
-
-template<typename T>
-struct Ambiguous : Indirect<T>, T {
-/* since-cxx23-warning-re@-1 {{direct base '(lambda at {{.+}})' is inaccessible due to ambiguity:
-    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> Indirect<class (lambda at {{.+}})> -> class (lambda at {{.+}})
-    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
-//   since-cxx23-note-re@#cwg2881-f4 {{in instantiation of template class 'cwg2881::Ambiguous<(lambda at {{.+}})>' requested here}}
-//   since-cxx34-note-re@#cwg2881-f4-call {{while substituting deduced template arguments into function template 'f4' [with L = (lambda at {{.+}})]}}
-  using Indirect<T>::operator();
-};
-
-template <typename L>
-constexpr auto f3(L l) -> decltype(Private<L>{l}()) { return l(); } // #cwg2881-f3
-
-template <typename L>
-constexpr auto f4(L l) -> decltype(Ambiguous<L>{{l}, l}()) { return l(); } // #cwg2881-f4
-
-template<typename T>
-concept is_callable = requires(T t) { { t() }; };
-
-void g() {
-  int x = 0;
-  auto lambda = [x](this auto self) {};
-  f3(lambda);
-  // since-cxx23-error@-1 {{no matching function for call to 'f3'}}
-  //   since-cxx23-note-re@#cwg2881-f3 {{candidate template ignored: substitution failure [with L = (lambda at {{.+}})]: invalid explicit object parameter type 'cwg2881::Private<(lambda at {{.+}})>' in lambda with capture; the type must derive publicly from the lambda}}
-  f4(lambda); // #cwg2881-f4-call
-  // expected-error@-1 {{no matching function for call to 'f4'}}
-  //   expected-note-re@-2 {{while substituting deduced template arguments into function template 'f4' [with L = (lambda at {{.+}})]}}
-  /*   expected-note-re@#cwg2881-f4 {{candidate template ignored: substitution failure [with L = (lambda at {{.+}})]: lambda '(lambda at {{.+}})' is inaccessible due to ambiguity:
-    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> Indirect<class (lambda at {{.+}})> -> class (lambda at {{.+}})
-    struct cwg2881::Ambiguous<class (lambda at {{.+}})> -> class (lambda at {{.+}})}}*/
-  static_assert(!is_callable<Private<decltype(lambda)>>);
-  static_assert(!is_callable<Ambiguous<decltype(lambda)>>);
-}
-#endif
-} // namespace cwg2881
+// cwg2881 is in cwg2881.cpp
 
 namespace cwg2882 { // cwg2882: 2.7
 struct C {
diff --git a/clang/test/CXX/drs/cwg2xx.cpp b/clang/test/CXX/drs/cwg2xx.cpp
index a4995ddc2c58..566eba71310a 100644
--- a/clang/test/CXX/drs/cwg2xx.cpp
+++ b/clang/test/CXX/drs/cwg2xx.cpp
@@ -6,10 +6,7 @@
 // RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx11,since-cxx14,since-cxx17,since-cxx20 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx11,since-cxx14,since-cxx17,since-cxx20 -fexceptions -fcxx-exceptions -pedantic-errors
 
-// FIXME: diagnostic above is emitted only on Windows platforms
-// PR13819 -- __SIZE_TYPE__ is incompatible.
-typedef __SIZE_TYPE__ size_t;
-// cxx98-error@-1 0-1 {{'long long' is a C++11 extension}}
+typedef __decltype(sizeof(0)) size_t;
 
 #if __cplusplus == 199711L
 #define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
diff --git a/clang/test/CXX/drs/cwg329.cpp b/clang/test/CXX/drs/cwg329.cpp
new file mode 100644
index 000000000000..6ea01805580a
--- /dev/null
+++ b/clang/test/CXX/drs/cwg329.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+
+namespace cwg329 { // cwg329: 3.5
+  struct B {};
+  template<typename T> struct A : B {
+    friend void f(A a) { g(a); }
+    friend void h(A a) { g(a); }
+    // expected-error@-1 {{use of undeclared identifier 'g'}}
+    //   expected-note@#cwg329-h-call {{in instantiation of member function 'cwg329::h' requested here}}
+    friend void i(B b) {} // #cwg329-i
+    // expected-error@-1 {{redefinition of 'i'}}
+    //   expected-note@#cwg329-b {{in instantiation of template class 'cwg329::A<char>' requested here}}
+    //   expected-note@#cwg329-i {{previous definition is here}}
+  };
+  A<int> a;
+  A<char> b; // #cwg329-b
+
+  void test() {
+    h(a); // #cwg329-h-call
+  }
+} // namespace cwg329
diff --git a/clang/test/CXX/drs/cwg390.cpp b/clang/test/CXX/drs/cwg390.cpp
new file mode 100644
index 000000000000..8ee41a87cf47
--- /dev/null
+++ b/clang/test/CXX/drs/cwg390.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+
+namespace cwg390 { // cwg390: 3.3
+  template<typename T>
+  struct A {
+    A() { f(); }
+    // expected-warning@-1 {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the constructor of 'cwg390::A<int>'}}
+    //   expected-note@#cwg390-A-int {{in instantiation of member function 'cwg390::A<int>::A' requested here}}
+    //   expected-note@#cwg390-f {{'f' declared here}}
+    virtual void f() = 0; // #cwg390-f
+    virtual ~A() = 0;
+  };
+  template<typename T> A<T>::~A() { T::error; }
+  // expected-error@-1 {{type 'int' cannot be used prior to '::' because it has no members}}
+  //   expected-note@#cwg390-A-int {{in instantiation of member function 'cwg390::A<int>::~A' requested here}}
+  template<typename T> void A<T>::f() { T::error; } // ok, not odr-used
+  struct B : A<int> { // #cwg390-A-int
+    void f() {}
+  } b;
+} // namespace cwg390
diff --git a/clang/test/CXX/drs/cwg3xx.cpp b/clang/test/CXX/drs/cwg3xx.cpp
index 754eb2315728..e3cd0725c817 100644
--- a/clang/test/CXX/drs/cwg3xx.cpp
+++ b/clang/test/CXX/drs/cwg3xx.cpp
@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -std=c++98 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx98 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++11 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx11-14,since-cxx11 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++14 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx11-14,since-cxx11 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++17 -verify=expected,cxx98-17,cxx98-20,since-cxx11,since-cxx17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++20 -verify=expected,cxx98-20,cxx20-23,since-cxx11,since-cxx17 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++23 -verify=expected,cxx20-23,cxx23,since-cxx11,since-cxx17,since-cxx23 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++2c -verify=expected,cxx20-23,cxx23,since-cxx11,since-cxx17,since-cxx23 -triple %itanium_abi_triple %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++98 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx98 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++11 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx11-14,since-cxx11 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++14 -verify=expected,cxx98-14,cxx98-17,cxx98-20,cxx11-14,since-cxx11 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++17 -verify=expected,cxx98-17,cxx98-20,since-cxx11,since-cxx17 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 -verify=expected,cxx98-20,cxx20-23,since-cxx11,since-cxx17 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++23 -verify=expected,cxx20-23,cxx23,since-cxx11,since-cxx17,since-cxx23 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2c -verify=expected,cxx20-23,cxx23,since-cxx11,since-cxx17,since-cxx23 -triple x86_64-linux-gnu %s -fexceptions -fcxx-exceptions -pedantic-errors
 
 #if __cplusplus == 199711L
 #define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
@@ -17,6 +17,19 @@
 #define __enable_constant_folding
 #endif
 
+namespace std {
+template<bool Cond, typename T = void>
+struct enable_if;
+
+template<typename T>
+struct enable_if<true, T> {
+  typedef T type;
+};
+
+template<typename T>
+struct enable_if<false, T> { };
+} // namespace std
+
 namespace cwg300 { // cwg300: 2.7
   template<typename R, typename A> void f(R (&)(A)) {}
   int g(int);
@@ -432,25 +445,7 @@ namespace cwg328 { // cwg328: 2.7
   //   expected-note@#cwg328-A {{forward declaration of 'cwg328::A'}}
 } // namespace cwg328
 
-namespace cwg329 { // cwg329: 3.5
-  struct B {};
-  template<typename T> struct A : B {
-    friend void f(A a) { g(a); }
-    friend void h(A a) { g(a); }
-    // expected-error@-1 {{use of undeclared identifier 'g'}}
-    //   expected-note@#cwg329-h-call {{in instantiation of member function 'cwg329::h' requested here}}
-    friend void i(B b) {} // #cwg329-i
-    // expected-error@-1 {{redefinition of 'i'}}
-    //   expected-note@#cwg329-b {{in instantiation of template class 'cwg329::A<char>' requested here}}
-    //   expected-note@#cwg329-i {{previous definition is here}}
-  };
-  A<int> a;
-  A<char> b; // #cwg329-b
-
-  void test() {
-    h(a); // #cwg329-h-call
-  }
-} // namespace cwg329
+// cwg329 is in cwg329.cpp
 
 namespace cwg330 { // cwg330: 7
   // Conversions between P and Q will be allowed by P0388.
@@ -560,13 +555,13 @@ namespace cwg331 { // cwg331: 11
 
 namespace cwg332 { // cwg332: dup 577
   void f(volatile void);
-  // expected-error@-1 {{'void' as parameter must not have type qualifiers}}
-  // cxx20-23-warning@-2 {{volatile-qualified parameter type 'volatile void' is deprecated}}
+  // cxx20-23-warning@-1 {{volatile-qualified parameter type 'volatile void' is deprecated}}
+  // expected-error@-2 {{'void' as parameter must not have type qualifiers}}
   void g(const void);
   // expected-error@-1 {{'void' as parameter must not have type qualifiers}}
   void h(int n, volatile void);
-  // expected-error@-1 {{'void' must be the first and only parameter if specified}}
-  // cxx20-23-warning@-2 {{volatile-qualified parameter type 'volatile void' is deprecated}}
+  // cxx20-23-warning@-1 {{volatile-qualified parameter type 'volatile void' is deprecated}}
+  // expected-error@-2 {{'void' must be the first and only parameter if specified}}
 } // namespace cwg332
 
 namespace cwg333 { // cwg333: 2.7
@@ -746,10 +741,9 @@ namespace cwg345 { // cwg345: 2.7
   // expected-error@-1 {{typename specifier refers to non-type member 'X' in 'cwg345::A'}}
   //   expected-note@#cwg345-f-a {{in instantiation of function template specialization 'cwg345::f<cwg345::A>' requested here}}
   //   expected-note@#cwg345-int-X {{referenced member 'X' is declared here}}
-  void f(A a, B b) {
-    f(b);
-    f(a); // #cwg345-f-a
-  }
+
+  template void f<A>(A); // #cwg345-f-a
+  template void f<B>(B);
 } // namespace cwg345
 
 // cwg346: na
@@ -780,24 +774,21 @@ namespace cwg347 { // cwg347: 2.7
 
 namespace cwg349 { // cwg349: no
   struct A {
-    template <class T> operator T ***() {
-      int ***p = 0;
-      return p;
-      // cxx98-20-error@-1 {{cannot initialize return object of type 'const int ***' with an lvalue of type 'int ***'}}
-      // since-cxx23-error@-2 {{cannot initialize return object of type 'const int ***' with an rvalue of type 'int ***'}}
-      //   expected-note@#cwg349-p1 {{in instantiation of function template specialization 'cwg349::A::operator const int ***<const int>' requested here}}
-    }
+    template <class T, typename std::enable_if<!__is_const(T), int>::type = 0>
+    // cxx98-error@-1 {{default template arguments for a function template are a C++11 extension}}
+    operator T ***(); // #cwg349-A
   };
 
   // FIXME: This is valid.
   A a;
   const int *const *const *p1 = a; // #cwg349-p1
+  // expected-error@-1 {{no viable conversion from 'A' to 'const int *const *const *'}}
+  //   expected-note@#cwg349-A {{candidate template ignored: requirement '!__is_const(const int)' was not satisfied [with T = const int]}}
 
   struct B {
-    template <class T> operator T ***() {
-      const int ***p = 0;
-      return p;
-    }
+    template <class T, typename std::enable_if<__is_const(T), int>::type = 0>
+    // cxx98-error@-1 {{default template arguments for a function template are a C++11 extension}}
+    operator T ***();
   };
 
   // FIXME: This is invalid.
@@ -1296,13 +1287,10 @@ namespace cwg374 { // cwg374: 7
 // cwg376: na
 
 namespace cwg377 { // cwg377: 2.7
-  enum E {
-  // expected-error@-1 {{enumeration values exceed range of largest integer}}
-    a = -__LONG_LONG_MAX__ - 1,
-    // cxx98-error@-1 {{'long long' is a C++11 extension}}
-    b = 2 * (unsigned long long)__LONG_LONG_MAX__
-    // cxx98-error@-1 {{'long long' is a C++11 extension}}
-    // cxx98-error@-2 {{'long long' is a C++11 extension}}
+  enum E { // #cwg377-E
+  // expected-error@#cwg377-E {{enumeration values exceed range of largest integer}}
+    a = -__LONG_MAX__ - 1,
+    b = 2 * (unsigned long)__LONG_MAX__
   };
 } // namespace cwg377
 
@@ -1617,24 +1605,7 @@ namespace cwg389 { // cwg389: no
   }
 } // namespace cwg389
 
-namespace cwg390 { // cwg390: 3.3
-  template<typename T>
-  struct A {
-    A() { f(); }
-    // expected-warning@-1 {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the constructor of 'cwg390::A<int>'}}
-    //   expected-note@#cwg390-A-int {{in instantiation of member function 'cwg390::A<int>::A' requested here}}
-    //   expected-note@#cwg390-f {{'f' declared here}}
-    virtual void f() = 0; // #cwg390-f
-    virtual ~A() = 0;
-  };
-  template<typename T> A<T>::~A() { T::error; }
-  // expected-error@-1 {{type 'int' cannot be used prior to '::' because it has no members}}
-  //   expected-note@#cwg390-A-int {{in instantiation of member function 'cwg390::A<int>::~A' requested here}}
-  template<typename T> void A<T>::f() { T::error; } // ok, not odr-used
-  struct B : A<int> { // #cwg390-A-int
-    void f() {}
-  } b;
-} // namespace cwg390
+// cwg390 is in cwg390.cpp
 
 namespace cwg391 { // cwg391: 2.8 c++11
   // FIXME: Should this apply to C++98 too?
@@ -1684,7 +1655,8 @@ void h() {
 namespace cwg395 { // cwg395: 3.0
   struct S {
     template <typename T, int N>(&operator T())[N];
-    // expected-error@-1 {{cannot specify any part of a return type in the declaration of a conversion function}}
+    // cxx98-error@-1 {{cannot specify any part of a return type in the declaration of a conversion function}}
+    // since-cxx11-error@-2 {{cannot specify any part of a return type in the declaration of a conversion function; use an alias template to declare a conversion to 'T (&)[N]'}}
     template <typename T, int N> operator(T (&)[N])();
     // expected-error@-1 {{expected ')'}}
     //   expected-note@-2 {{to match this '('}}
@@ -1694,9 +1666,9 @@ namespace cwg395 { // cwg395: 3.0
     template <typename T, typename U> operator T (U::*)()() const { return 0; }
     // expected-error@-1 {{a type specifier is required for all declarations}}
     // expected-error@-2 {{conversion function cannot have any parameters}}
-    // expected-error@-3 {{cannot specify any part of a return type in the declaration of a conversion function}}
-    // expected-error@-4 {{conversion function cannot convert to a function type}}
-
+    // cxx98-error@-3 {{cannot specify any part of a return type in the declaration of a conversion function}}
+    // since-cxx11-error@-4 {{cannot specify any part of a return type in the declaration of a conversion function; use an alias template to declare a conversion to 'T (())() const'}}
+    // expected-error@-5 {{conversion function cannot convert to a function type}}
   };
 
   struct null1_t {
diff --git a/clang/test/CXX/drs/cwg4xx.cpp b/clang/test/CXX/drs/cwg4xx.cpp
index eccfbea01492..ee2940d7f2fa 100644
--- a/clang/test/CXX/drs/cwg4xx.cpp
+++ b/clang/test/CXX/drs/cwg4xx.cpp
@@ -1,10 +1,10 @@
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++98 %s -verify=expected,cxx98-14,cxx98-17,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++11 %s -verify=expected,cxx98-14,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++14 %s -verify=expected,cxx98-14,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++17 %s -verify=expected,since-cxx17,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++20 %s -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++23 %s -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++2c %s -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++98 %s -triple x86_64-linux-gnu -verify=expected,cxx98-14,cxx98-17,cxx98 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++11 %s -triple x86_64-linux-gnu -verify=expected,cxx98-14,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++14 %s -triple x86_64-linux-gnu -verify=expected,cxx98-14,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++17 %s -triple x86_64-linux-gnu -verify=expected,since-cxx17,cxx98-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++20 %s -triple x86_64-linux-gnu -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++23 %s -triple x86_64-linux-gnu -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: env ASAN_OPTIONS=detect_stack_use_after_return=0 %clang_cc1 -std=c++2c %s -triple x86_64-linux-gnu -verify=expected,since-cxx20,since-cxx17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 
 #if __cplusplus == 199711L
 #define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
@@ -309,15 +309,14 @@ namespace cwg413 { // cwg413: 2.7
   // expected-error@-1 {{excess elements in struct initializer}}
 
   struct E {};
-  struct T { // #cwg413-T
+  struct S2 {
     int a;
     E e;
     int b;
   };
-  T t1 = { 1, {}, 2 };
-  T t2 = { 1, 2 };
+  S2 s2_1 = { 1, {}, 2 };
+  S2 s2_2 = { 1, 2 };
   // expected-error@-1 {{initializer for aggregate with no elements requires explicit braces}}
-  //   expected-note@#cwg413-T {{'cwg413::T' declared here}}
 } // namespace cwg413
 
 namespace cwg414 { // cwg414: dup 305
@@ -534,16 +533,28 @@ namespace cwg425 { // cwg425: 2.7
   struct A { template<typename T> operator T() const; } a;
   float f = 1.0f * a;
   // expected-error@-1 {{use of overloaded operator '*' is ambiguous (with operand types 'float' and 'struct A')}}
-  //   expected-note@-2 +{{built-in candidate operator*}}
+  //   expected-note-re@-2 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-3 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-4 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-5 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-6 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-7 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-8 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-9 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-10 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-11 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-12 {{built-in candidate operator*{{.*}}}}
+  //   expected-note-re@-13 {{built-in candidate operator*{{.*}}}}
 
   template<typename T> struct is_float;
   template<> struct is_float<float> { typedef void type; };
 
+#if __cplusplus >= 201103L
   struct B {
     template<typename T, typename U = typename is_float<T>::type> operator T() const;
-    // cxx98-error@-1 {{default template arguments for a function template are a C++11 extension}}
   } b;
   float g = 1.0f * b; // ok
+#endif
 } // namespace cwg425
 
 namespace cwg427 { // cwg427: 2.7
@@ -767,12 +778,12 @@ namespace cwg446 { // cwg446: 2.8
     //   expected-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
     b ? A() : A();
     // cxx98-14-error@-1 {{call to deleted constructor of 'A'}}
-    //   expected-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
+    //   cxx98-14-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
 
     void(b ? a : c);
     b ? a : C();
     // expected-error@-1 {{call to deleted constructor of 'A'}}
-    //   cxx98-14-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
+    //   expected-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
     b ? c : A();
     // cxx98-14-error@-1 {{call to deleted constructor of 'A'}}
     //   cxx98-14-note@#cwg446-deleted {{'A' has been explicitly marked deleted here}}
diff --git a/clang/test/CXX/drs/cwg5xx.cpp b/clang/test/CXX/drs/cwg5xx.cpp
index f29c1e813101..450f8b211326 100644
--- a/clang/test/CXX/drs/cwg5xx.cpp
+++ b/clang/test/CXX/drs/cwg5xx.cpp
@@ -475,10 +475,9 @@ namespace cwg535 { // cwg535: 3.1
 // cwg538: na
 
 namespace cwg539 { // cwg539: 3.4
-const f(
-// expected-error@-1 {{a type specifier is required for all declarations}}
-    const a) {
-    // expected-error@-1 {{unknown type name 'a'}}
+const f(const a) {
+// expected-error@-1 {{unknown type name 'a'}}
+// expected-error@-2 {{a type specifier is required for all declarations}}
   const b;
   // expected-error@-1 {{a type specifier is required for all declarations}}
   new const;
@@ -512,8 +511,14 @@ const f(
   { for (const n // #cwg539-for
   // since-cxx11-error@-1 {{unknown type name 'n'}}
          : arr) ; {} }
-         // since-cxx11-error@-1 +{{}}
-         //   since-cxx11-note@#cwg539-for {{}}
+         // since-cxx11-error-re@-1 {{{{.*}}}}
+         // since-cxx11-error-re@-2 {{{{.*}}}}
+         // since-cxx11-error-re@-3 {{{{.*}}}}
+         // since-cxx11-error-re@-4 {{{{.*}}}}
+         // since-cxx11-error-re@-5 {{{{.*}}}}
+         // since-cxx11-error-re@-6 {{{{.*}}}}
+         //   since-cxx11-note-re@#cwg539-for {{{{.*}}}}
+         // since-cxx11-error-re@-8 {{{{.*}}}}
   (void) [](const) {};
   // since-cxx11-error@-1 {{a type specifier is required for all declarations}}
   (void) [](const n) {};
@@ -537,9 +542,9 @@ namespace cwg540 { // cwg540: 2.7
   typedef const a &c; // #cwg540-typedef-a-c
   // expected-warning@-1 {{'const' qualifier on reference type 'a' (aka 'int &') has no effect}}
   typedef const b &c; // #cwg540-typedef-b-c
+  // expected-warning@#cwg540-typedef-b-c {{'const' qualifier on reference type 'b' (aka 'const int &') has no effect}}
   // expected-error@#cwg540-typedef-b-c {{typedef redefinition with different types ('const int &' vs 'int &')}}
   //   expected-note@#cwg540-typedef-a-c {{previous definition is here}}
-  // expected-warning@#cwg540-typedef-b-c {{'const' qualifier on reference type 'b' (aka 'const int &') has no effect}}
 } // namespace cwg540
 
 namespace cwg541 { // cwg541: 2.7
@@ -1150,12 +1155,12 @@ namespace cwg588 { // cwg588: 2.7
     int a = s.f();
     int b = s.n;
     // expected-error@-1 {{member 'n' found in multiple base classes of different types}}
-    //   expected-note@#cwg588-k {{in instantiation of function template specialization 'cwg588::f<cwg588::B>' requested here}}
+    //   expected-note@#cwg588-inst {{in instantiation of function template specialization 'cwg588::f<cwg588::B>' requested here}}
     //   expected-note@#cwg588-A {{member found by ambiguous name lookup}}
     //   expected-note@#cwg588-B {{member found by ambiguous name lookup}}
   }
   struct B { int n; }; // #cwg588-B
-  int k = f<B>(); // #cwg588-k
+  template int f<B>(); // #cwg588-inst
 } // namespace cwg588
 
 namespace cwg589 { // cwg589: 2.7
diff --git a/clang/test/CXX/drs/cwg6xx.cpp b/clang/test/CXX/drs/cwg6xx.cpp
index 3937a80d4f3c..3f91780d3366 100644
--- a/clang/test/CXX/drs/cwg6xx.cpp
+++ b/clang/test/CXX/drs/cwg6xx.cpp
@@ -2,9 +2,9 @@
 // RUN: %clang_cc1 -std=c++11 %s -verify=expected,cxx11-20,cxx98-17,cxx11-17,cxx98-14,since-cxx11,cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++14 %s -verify=expected,cxx11-20,cxx98-17,cxx11-17,cxx98-14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++17 %s -verify=expected,cxx11-20,cxx98-17,cxx11-17,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++20 %s -verify=expected,cxx11-20,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 %s -verify=expected,since-cxx20,cxx11-20,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++23 %s -verify=expected,since-cxx20,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2c %s -verify=expected,since-cxx20,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 
 #if __cplusplus == 199711L
 #define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
@@ -269,7 +269,8 @@ namespace cwg625 { // cwg625: 2.9
   void f(int);
   void (*p)(auto) = f;
   // cxx98-error@-1 {{'auto' type specifier is a C++11 extension}}
-  // expected-error@-2 {{'auto' not allowed in function prototype}}
+  // cxx98-17-error@-2 {{'auto' not allowed in function prototype}}
+  // since-cxx20-error@-3 {{'auto' not allowed in function prototype that is not a function declaration}}
 } // namespace cwg625
 
 namespace cwg626 { // cwg626: 2.7
@@ -839,12 +840,12 @@ namespace cwg662 { // cwg662: 2.7
     T &tr = t;
     T *tp = &t;
     // expected-error@-1 {{'tp' declared as a pointer to a reference of type 'int &'}}
-    //   expected-note@#cwg662-f-call {{in instantiation of function template specialization 'cwg662::f<int &>' requested here}}
+    //   expected-note@#cwg662-inst {{in instantiation of function template specialization 'cwg662::f<int &>' requested here}}
 #if __cplusplus >= 201103L
     auto *ap = &t;
 #endif
   }
-  void g(int n) { f<int&>(n); } // #cwg662-f-call
+  template void f<int&>(int&);  // #cwg662-inst
 } // namespace cwg662
 
 namespace cwg663 { // cwg663: sup P1949
@@ -904,8 +905,8 @@ namespace cwg666 { // cwg666: 2.8
   }
   struct X { static const int type = 0; };
   struct Y { typedef int type; };
-  int a = f<X>();
-  int b = f<Y>(); // #cwg666-f-Y
+  template int f<X>();
+  template int f<Y>();  // #cwg666-f-Y
 } // namespace cwg666
 
 // Triviality is entirely different in C++98.
@@ -1005,25 +1006,25 @@ namespace cwg674 { // cwg674: 8
 
   class X {
     friend int cwg674::f(int);
-    friend int cwg674::g(int);
-    friend int cwg674::h<>(int);
+    friend int cwg674::g<>(int);
+    friend int cwg674::h(int);
     int n; // #cwg674-X-n
   };
 
   template<typename T> int f(T) { return X().n; }
   int g(int) { return X().n; }
-  template<typename T> int g(T) { return X().n; }
   // expected-error@-1 {{'n' is a private member of 'cwg674::X'}}
-  //   expected-note@#cwg674-g-int {{in instantiation of function template specialization 'cwg674::g<int>' requested here}}
   //   expected-note@#cwg674-X-n {{implicitly declared private here}}
+  template<typename T> int g(T) { return X().n; }
   int h(int) { return X().n; }
+  template<typename T> int h(T) { return X().n; }
   // expected-error@-1 {{'n' is a private member of 'cwg674::X'}}
+  //   expected-note@#cwg674-h-int {{in instantiation of function template specialization 'cwg674::h<int>' requested here}}
   //   expected-note@#cwg674-X-n {{implicitly declared private here}}
-  template<typename T> int h(T) { return X().n; }
 
   template int f(int);
-  template int g(int); // #cwg674-g-int
-  template int h(int);
+  template int g(int);
+  template int h(int); // #cwg674-h-int
 
 
   struct Y {
@@ -1038,26 +1039,26 @@ namespace cwg674 { // cwg674: 8
 
   class Z {
     friend int Y::f(int);
-    friend int Y::g(int);
-    friend int Y::h<>(int);
+    friend int Y::g<>(int);
+    friend int Y::h(int);
     int n; // #cwg674-Z-n
   };
 
   template<typename T> int Y::f(T) { return Z().n; }
   int Y::g(int) { return Z().n; }
-  template<typename T> int Y::g(T) { return Z().n; }
   // expected-error@-1 {{'n' is a private member of 'cwg674::Z'}}
-  //   expected-note@#cwg674-Y-g-int {{in instantiation of function template specialization 'cwg674::Y::g<int>' requested here}}
   //   expected-note@#cwg674-Z-n {{implicitly declared private here}}
+  template<typename T> int Y::g(T) { return Z().n; }
   int Y::h(int) { return Z().n; }
+  template<typename T> int Y::h(T) { return Z().n; }
   // expected-error@-1 {{'n' is a private member of 'cwg674::Z'}}
+  //   expected-note@#cwg674-Y-h-int {{in instantiation of function template specialization 'cwg674::Y::h<int>' requested here}}
   //   expected-note@#cwg674-Z-n {{implicitly declared private here}}
-  template<typename T> int Y::h(T) { return Z().n; }
 
   // FIXME: Should the <> be required here?
   template int Y::f<>(int);
-  template int Y::g<>(int); // #cwg674-Y-g-int
-  template int Y::h<>(int);
+  template int Y::g<>(int);
+  template int Y::h<>(int); // #cwg674-Y-h-int
 } // namespace cwg674
 
 namespace cwg675 { // cwg675: dup 739
diff --git a/clang/test/CXX/drs/cwg7xx.cpp b/clang/test/CXX/drs/cwg7xx.cpp
index 84bcc07bf0a3..7f49f5ecabf0 100644
--- a/clang/test/CXX/drs/cwg7xx.cpp
+++ b/clang/test/CXX/drs/cwg7xx.cpp
@@ -1,10 +1,10 @@
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++98 %s -verify=expected,cxx98,cxx98-14,cxx98-11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++11 %s -verify=expected,cxx98-14,cxx98-11,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++14 %s -verify=expected,cxx98-14,since-cxx14,since-cxx11,cxx14 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++17 %s -verify=expected,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %s -verify=expected,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++23 %s -verify=expected,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++2c %s -verify=expected,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++17 %s -verify=expected,since-cxx17,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++20 %s -verify=expected,since-cxx17,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++23 %s -verify=expected,since-cxx17,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++2c %s -verify=expected,since-cxx17,since-cxx14,since-cxx11 -fexceptions -fcxx-exceptions -pedantic-errors
 
 #if __cplusplus == 199711L
 #define static_assert(...) __extension__ _Static_assert(__VA_ARGS__)
@@ -35,8 +35,6 @@ namespace cwg712 { // cwg712: partial
         use(a);
         use((a));
         use(cond ? a : a);
-        use((cond, a));
-        // expected-warning@-1 {{left operand of comma operator has no effect}}
 
         (void)a;
         // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg712::f'}} FIXME
@@ -49,10 +47,13 @@ namespace cwg712 { // cwg712: partial
         //   expected-note@#cwg712-f-a {{'a' declared here}}
         // expected-error@#cwg712-ternary {{reference to local variable 'a' declared in enclosing function 'cwg712::f'}} FIXME
         //   expected-note@#cwg712-f-a {{'a' declared here}}
-        (void)(cond, a); // #cwg712-comma
+        (void)(cond, a);
         // expected-error@-1 {{reference to local variable 'a' declared in enclosing function 'cwg712::f'}} FIXME
         //   expected-note@#cwg712-f-a {{'a' declared here}}
-        // expected-warning@#cwg712-comma {{left operand of comma operator has no effect}}
+        // expected-warning@-3 {{left operand of comma operator has no effect}}
+
+        use((cond, a));
+        // expected-warning@-1 {{left operand of comma operator has no effect}}
       }
     };
   }
@@ -136,8 +137,8 @@ namespace cwg727 { // cwg727: partial
       // expected-error@-2 {{class template specialization of 'C' not in class 'A' or an enclosing namespace}}
       //   expected-note@#cwg727-C {{explicitly specialized declaration is here}}
       template<> void A::f<double>();
-      // expected-error@-1 {{o function template matches function template specialization 'f'}}
-      // expected-error@-2 {{non-friend class member 'f' cannot have a qualified name}}
+      // expected-error@-1 {{non-friend class member 'f' cannot have a qualified name}}
+      // expected-error@-2 {{no function template matches function template specialization 'f'}}
       template<> int A::N<double>;
       // expected-error@-1 {{non-friend class member 'N' cannot have a qualified name}}
       // expected-error@-2 {{variable template specialization of 'N' not in class 'A' or an enclosing namespace}}
@@ -188,37 +189,46 @@ namespace cwg727 { // cwg727: partial
     template<typename T> void f() { T::error; }
     // expected-error@-1 {{type 'float' cannot be used prior to '::' because it has no members}}
     //   expected-note@#cwg727-f-float {{in instantiation of function template specialization 'cwg727::D<int>::f<float>' requested here}}
-    template<typename T> static const int N = T::error;
-    // cxx98-11-error@-1 {{variable templates are a C++14 extension}}
-    // expected-error@-2 {{type 'float' cannot be used prior to '::' because it has no members}}
-    //   expected-note@#cwg727-N-float {{in instantiation of static data member 'cwg727::D<int>::N<float>' requested here}}
 
     template<> struct C<int> {};
     template<> void f<int>() {}
-    template<> const int N<int>;
 
     template<typename T> struct C<T*> {};
-    template<typename T> static const int N<T*>;
-
-    template<typename>
-    struct E {
-      template<> void f<void>() {}
-      // expected-error@-1 {{no candidate function template was found for dependent member function template specialization}}
-    };
   };
 
   void d(D<int> di) {
     D<int>::C<int>();
     di.f<int>();
-    int a = D<int>::N<int>;
-
     D<int>::C<int*>();
-    int b = D<int>::N<int*>;
+    D<int>::C<float>();  // #cwg727-C-float
+  }
+
+  template void D<int>::f<float>();  // #cwg727-f-float
 
-    D<int>::C<float>(); // #cwg727-C-float
-    di.f<float>(); // #cwg727-f-float
-    int c = D<int>::N<float>; // #cwg727-N-float
+#if __cplusplus >= 201402L
+  template<typename>
+  struct E {
+    template<typename T> static const int N = T::error;
+    // since-cxx14-error@-1 {{type 'float' cannot be used prior to '::' because it has no members}}
+    //   since-cxx14-note@#cwg727-N-float {{in instantiation of static data member 'cwg727::E<int>::N<float>' requested here}}
+    template<> const int N<int>;
+    template<typename T> static const int N<T*>;
+  };
+  void e() {
+    int a = E<int>::N<int>;
+    int b = E<int>::N<int*>;
+    int c = E<int>::N<float>; // #cwg727-N-float
   }
+#endif
+
+  template<typename>
+  struct F {
+    template<typename>
+    struct F2 {
+      template<> void f<void>() {}
+      // expected-error@-1 {{no candidate function template was found for dependent member function template specialization}}
+    };
+  };
 
   namespace mixed_inner_outer_specialization {
 #if __cplusplus >= 201103L
@@ -294,23 +304,21 @@ namespace cwg727 { // cwg727: partial
     template<> int f2<T>() {}
     template<> int f2<U>() {}
 
+#if __cplusplus >= 201402L
     template<typename> static int v1;
-    // cxx98-11-error@-1 {{variable templates are a C++14 extension}}
     template<> int v1<T>; // #cwg727-v1-T
     template<> int v1<U>;
-    // expected-error@-1 {{duplicate member 'v1'}}
-    //   expected-note@#cwg727-Collision-int-int {{in instantiation of template class 'cwg727::Collision<int, int>' requested here}}
-    //   expected-note@#cwg727-v1-T {{previous}}
-
+    // since-cxx14-error@-1 {{duplicate member 'v1'}}
+    //   since-cxx14-note@#cwg727-Collision-int-int {{in instantiation of template class 'cwg727::Collision<int, int>' requested here}}
+    //   since-cxx14-note@#cwg727-v1-T {{previous declaration is here}}
+#endif
+#if __cplusplus >= 201703L
     template<typename> static inline int v2;
-    // cxx98-11-error@-1 {{variable templates are a C++14 extension}}
-    // cxx98-14-error@-2 {{inline variables are a C++17 extension}}
     template<> inline int v2<T>; // #cwg727-v2-T
-    // cxx98-14-error@-1 {{inline variables are a C++17 extension}}
     template<> inline int v2<U>;
-    // cxx98-14-error@-1 {{inline variables are a C++17 extension}}
-    // expected-error@-2 {{duplicate member 'v2'}}
-    //   expected-note@#cwg727-v2-T {{previous declaration is here}}
+    // since-cxx17-error@-1 {{duplicate member 'v2'}}
+    //   since-cxx17-note@#cwg727-v2-T {{previous declaration is here}}
+#endif
 
     // FIXME: Missing diagnostic for duplicate class explicit specialization.
     template<typename> struct S1;
@@ -321,7 +329,8 @@ namespace cwg727 { // cwg727: partial
     template<> struct S2<T> {}; // #cwg727-S2-T
     template<> struct S2<U> {};
     // expected-error@-1 {{redefinition of 'S2<int>'}}
-    //   expected-note@#cwg727-S2-T {{previous}}
+    //   cxx98-11-note@#cwg727-Collision-int-int {{in instantiation of template class 'cwg727::Collision<int, int>' requested here}}
+    //   expected-note@#cwg727-S2-T {{previous definition is here}}
   };
   Collision<int, int> c; // #cwg727-Collision-int-int
 } // namespace cwg727
diff --git a/clang/test/CXX/drs/cwg98.cpp b/clang/test/CXX/drs/cwg98.cpp
new file mode 100644
index 000000000000..5618b82388bf
--- /dev/null
+++ b/clang/test/CXX/drs/cwg98.cpp
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -std=c++98 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++11 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++14 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++17 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++20 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++23 %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+// RUN: %clang_cc1 -std=c++2c %s -fexceptions -fcxx-exceptions -pedantic-errors -verify
+
+namespace cwg98 { // cwg98: 2.7
+  void test(int n) {
+    switch (n) {
+      try { // #cwg98-try
+        case 0:
+        // expected-error@-1 {{cannot jump from switch statement to this case label}}
+        //   expected-note@#cwg98-try {{jump bypasses initialization of try block}}
+        x:
+          throw n;
+      } catch (...) { // #cwg98-catch
+        case 1:
+        // expected-error@-1 {{cannot jump from switch statement to this case label}}
+        //   expected-note@#cwg98-catch {{jump bypasses initialization of catch block}}
+        y:
+          throw n;
+      }
+      case 2:
+        goto x;
+        // expected-error@-1 {{cannot jump from this goto statement to its label}}
+        //   expected-note@#cwg98-try {{jump bypasses initialization of try block}}
+      case 3:
+        goto y;
+        // expected-error@-1 {{cannot jump from this goto statement to its label}}
+        //   expected-note@#cwg98-catch {{jump bypasses initialization of catch block}}
+    }
+  }
+} // namespace cwg98
diff --git a/clang/test/CXX/drs/cwg9xx.cpp b/clang/test/CXX/drs/cwg9xx.cpp
index 96e46742650d..3863cb4600fc 100644
--- a/clang/test/CXX/drs/cwg9xx.cpp
+++ b/clang/test/CXX/drs/cwg9xx.cpp
@@ -59,29 +59,33 @@ struct A {
 struct B : private A { // #cwg952-B
 };
 struct C : B {
-  void f() {
-    I i1;
-    // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
-    //   expected-note@#cwg952-B {{constrained by private inheritance here}}
-    //   expected-note@#cwg952-I {{member is declared here}}
-  }
-  I i2;
+  void f();
+  I i1;
   // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
   //   expected-note@#cwg952-B {{constrained by private inheritance here}}
   //   expected-note@#cwg952-I {{member is declared here}}
   struct D {
-    I i3;
+    I i2;
     // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
     //   expected-note@#cwg952-B {{constrained by private inheritance here}}
     //   expected-note@#cwg952-I {{member is declared here}}
-    void g() {
-      I i4;
-      // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
-      //   expected-note@#cwg952-B {{constrained by private inheritance here}}
-      //   expected-note@#cwg952-I {{member is declared here}}
-    }
+    void g();
   };
 };
+
+void C::f() {
+  I i3;
+  // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
+  //   expected-note@#cwg952-B {{constrained by private inheritance here}}
+  //   expected-note@#cwg952-I {{member is declared here}}
+}
+
+void C::D::g() {
+  I i4;
+  // expected-error@-1 {{'I' is a private member of 'cwg952::example1::A'}}
+  //   expected-note@#cwg952-B {{constrained by private inheritance here}}
+  //   expected-note@#cwg952-I {{member is declared here}}
+}
 } // namespace example1
 namespace example2 {
 struct A {