[Clang] update reasoned delete diagnostic kind to use Extension, making it pedantic only

clang/docs/ReleaseNotes.rst

@@ -555,6 +555,8 @@ Improvements to Clang's diagnostics
       getS(); // Now diagnoses "Reason 2", previously diagnoses "Reason 1"
     }
 
+- Clang now diagnoses ``= delete("reason")`` extension warnings only in pedantic mode rather than on by default. (#GH109311).
+
 Improvements to Clang's time-trace
 ----------------------------------
 

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -976,7 +976,7 @@ def warn_cxx98_compat_defaulted_deleted_function : Warning<
   "%select{defaulted|deleted}0 function definitions are incompatible with C++98">,
   InGroup<CXX98Compat>, DefaultIgnore;
 
-def ext_delete_with_message : ExtWarn<
+def ext_delete_with_message : Extension<
   "'= delete' with a message is a C++2c extension">, InGroup<CXX26>;
 def warn_cxx23_delete_with_message : Warning<
   "'= delete' with a message is incompatible with C++ standards before C++2c">,

clang/test/Parser/cxx2c-delete-with-message.cpp

@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -std=c++23 -fsyntax-only -verify=expected,pre26 -pedantic %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify=expected,pre26 %s
+// RUN: %clang_cc1 -std=c++17 -fsyntax-only -verify=expected,pre26-pedantic -pedantic %s
 // RUN: %clang_cc1 -std=c++2c -fsyntax-only -verify=expected,compat -Wpre-c++26-compat %s
 // RUN: %clang_cc1 -std=c++2c -fsyntax-only -verify %s
 
@@ -7,15 +8,15 @@ struct S {
   void b() = delete(; // expected-error {{expected string literal}} expected-error {{expected ')'}} expected-note {{to match this '('}}
   void c() = delete(); // expected-error {{expected string literal}}
   void d() = delete(42); // expected-error {{expected string literal}}
-  void e() = delete("foo"[0]); // expected-error {{expected ')'}} expected-note {{to match this '('}} // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  void f() = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-
-  S() = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  ~S() = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  S(const S&) = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  S(S&&) = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  S& operator=(const S&) = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-  S& operator=(S&&) = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  void e() = delete("foo"[0]); // expected-error {{expected ')'}} expected-note {{to match this '('}} // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  void f() = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+
+  S() = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  ~S() = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  S(const S&) = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  S(S&&) = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  S& operator=(const S&) = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+  S& operator=(S&&) = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
 };
 
 struct T {
@@ -31,8 +32,8 @@ void a() = delete;
 void b() = delete(; // expected-error {{expected string literal}} expected-error {{expected ')'}} expected-note {{to match this '('}}
 void c() = delete(); // expected-error {{expected string literal}}
 void d() = delete(42); // expected-error {{expected string literal}}
-void e() = delete("foo"[0]); // expected-error {{expected ')'}} expected-note {{to match this '('}} // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
-void f() = delete("foo"); // pre26-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+void e() = delete("foo"[0]); // expected-error {{expected ')'}} expected-note {{to match this '('}} // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
+void f() = delete("foo"); // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2c}}
 
 constexpr const char *getMsg() { return "this is a message"; }
 void func() = delete(getMsg()); // expected-error {{expected string literal}}
@@ -49,3 +50,12 @@ struct C {
   U f = delete ("hello"); // expected-error {{cannot delete expression of type 'const char[6]'}}
 };
 }
+
+namespace GH109311 {
+void f() = delete
+#if __cpp_deleted_function >= 202403L
+    ("reason") // pre26-pedantic-warning {{'= delete' with a message is a C++2c extension}} \
+               // compat-warning {{'= delete' with a message is incompatible with C++ standards before C++2}}
+#endif
+;
+}