1 files changed, 57 insertions, 4 deletions
diff --git a/clang/test/AST/ByteCode/cxx23.cpp b/clang/test/AST/ByteCode/cxx23.cpp
index 72c751d..ce0a4777 100644
--- a/clang/test/AST/ByteCode/cxx23.cpp
+++ b/clang/test/AST/ByteCode/cxx23.cpp
@@ -1,8 +1,8 @@
 // UNSUPPORTED:  target={{.*}}-zos{{.*}}
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -verify=ref,ref20,all,all20 %s
-// RUN: %clang_cc1 -std=c++23 -fsyntax-only -fcxx-exceptions -verify=ref,ref23,all,all23 %s
-// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -verify=expected20,all,all20 %s -fexperimental-new-constant-interpreter
-// RUN: %clang_cc1 -std=c++23 -fsyntax-only -fcxx-exceptions -verify=expected23,all,all23 %s -fexperimental-new-constant-interpreter
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -Wno-deprecated-volatile -verify=ref,ref20,all,all20 %s
+// RUN: %clang_cc1 -std=c++23 -fsyntax-only -fcxx-exceptions -Wno-deprecated-volatile -verify=ref,ref23,all,all23 %s
+// RUN: %clang_cc1 -std=c++20 -fsyntax-only -fcxx-exceptions -Wno-deprecated-volatile -verify=expected20,all,all20 %s -fexperimental-new-constant-interpreter
+// RUN: %clang_cc1 -std=c++23 -fsyntax-only -fcxx-exceptions -Wno-deprecated-volatile -verify=expected23,all,all23 %s -fexperimental-new-constant-interpreter
 
 
 #define assert_active(F)   if (!__builtin_is_within_lifetime(&F)) (1/0);
@@ -393,6 +393,59 @@ namespace UnionMemberCallDiags {
   static_assert(g()); // all-error {{not an integral constant expression}} \
                       // all-note {{in call to}}
 }
+#endif
+
+namespace VolatileWrites {
+  constexpr void test1() {// all20-error {{never produces a constant expression}}
+    int k;
+    volatile int &m = k;
+    m = 10; // all20-note {{assignment to volatile-qualified type 'volatile int'}}
+  }
 
+  constexpr void test2() { // all20-error {{never produces a constant expression}}
+    volatile int k = 12;
 
+    k = 13; // all20-note {{assignment to volatile-qualified type 'volatile int'}}
+  }
+
+  constexpr void test3() { // all20-error {{never produces a constant expression}}
+    volatile int k = 12; // all20-note {{volatile object declared here}}
+
+    *((int *)&k) = 13; // all20-note {{assignment to volatile object 'k' is not allowed in a constant expression}}
+  }
+
+  constexpr void test4() { // all20-error {{never produces a constant expression}}
+    int k = 12;
+
+    *((volatile int *)&k) = 13; // all20-note {{assignment to volatile-qualified type 'volatile int' is not allowed in a constant expression}}
+  }
+
+#if __cplusplus >= 202302L
+  struct S {
+    volatile int k;
+  };
+  constexpr int test5() {
+    S s;
+    s.k = 12; // all-note {{assignment to volatile-qualified type 'volatile int' is not}}
+
+    return 0;
+  }
+  static_assert(test5() == 0); // all-error{{not an integral constant expression}} \
+                               // all-note {{in call to}}
 #endif
+
+  constexpr bool test6(volatile int k) { // ref20-error {{never produces a constant expression}}
+    k = 14; // ref20-note {{assignment to volatile-qualified type 'volatile int' is not}} \
+            // all-note {{assignment to volatile-qualified type 'volatile int' is not}}
+    return true;
+  }
+  static_assert(test6(5)); // all-error {{not an integral constant expression}} \
+                           // all-note {{in call to}}
+
+  constexpr bool test7(volatile int k) { // all-note {{declared here}}
+    *((int *)&k) = 13; // all-note {{assignment to volatile object 'k' is not allowed in a constant expression}}
+    return true;
+  }
+  static_assert(test7(12)); // all-error {{not an integral constant expression}} \
+                            // all-note {{in call to}}
+}