diff --git a/src/cmd_line.c b/src/cmd_line.c
index a1fc4154cb..446baa06f1 100644
--- a/src/cmd_line.c
+++ b/src/cmd_line.c
@@ -4317,7 +4317,9 @@ default mode (e.g., exception handling).
     if (!option_kind_used[(int)optk_digit_separators]) {
       digit_separators_enabled = TRUE;
     }  /* if */
-    if (rvalue_references_enabled && !gpp_mode && !clang_mode) {
+    if (rvalue_references_enabled &&
+        !gpp_version_is(<90000) && !clangcpp_version_is(<40000)) {
+      /* A field selection on a class prvalue is an xvalue (CWG 616). */
       selection_from_prvalue_is_xvalue = TRUE;
     }  /* if */
     relaxed_constexpr_enabled = TRUE;
diff --git a/src/exprutil.c b/src/exprutil.c
index db22dd4b7b..7cbb6b71b3 100644
--- a/src/exprutil.c
+++ b/src/exprutil.c
@@ -25271,6 +25271,10 @@ is_temp can be NULL if that information is not needed.
     clear_expr_or_stmt_traversal_block(&tblock);
     tblock.process_expr = examine_expr_for_auto_object;
     tblock.follow_addressing_path = TRUE;
+    /* A prvalue.field xvalue (CWG 616) names a subobject of the class
+       prvalue, so the class object must be considered as well. */
+    tblock.follow_class_rvalue_addressing_path =
+                                         selection_from_prvalue_is_xvalue;
     traverse_expr(expr, &tblock);
     is_auto_object = tblock.result;
     if (is_temp != NULL) *is_temp = tblock.is_temp;
@@ -25321,6 +25325,10 @@ underlying entity is a temporary, return *is_temp set to TRUE.
     clear_expr_or_stmt_traversal_block(&tblock);
     tblock.process_expr = examine_expr_for_auto_object;
     tblock.follow_addressing_path = TRUE;
+    /* A pointer into a prvalue.field xvalue (CWG 616) addresses a
+       subobject of the class prvalue. */
+    tblock.follow_class_rvalue_addressing_path =
+                                         selection_from_prvalue_is_xvalue;
     traverse_expr(expr, &tblock);
     is_addr_of_auto = tblock.result;
     *is_temp = tblock.is_temp;  
diff --git a/src/il_walk.c b/src/il_walk.c
index 12b733b2cd..fa5ba55834 100644
--- a/src/il_walk.c
+++ b/src/il_walk.c
@@ -3266,10 +3266,10 @@ Tips for proper use of the follow_addressing_path mode:
       switch (op) {
         case eok_dot_field:
           /* x.y:  Follow x. */
-          /* We don't have to test for the prvalue.field case here because its
-             result is a prvalue and therefore wouldn't get here, unless
-             follow_class_rvalue_addressing_path is TRUE, in which case
-             we want to keep going anyway. */
+          /* We don't have to test for the prvalue.field case here: it gets
+             here only if follow_class_rvalue_addressing_path is TRUE or if
+             its result is an xvalue (selection_from_prvalue_is_xvalue,
+             CWG 616), and in both cases we want to keep going. */
           traverse_expr(operand1, tblock);
           break;
         case eok_points_to_field:
@@ -3278,10 +3278,10 @@ Tips for proper use of the follow_addressing_path mode:
           break;
         case eok_pm_field:
           /* x.*pm:  Follow x. */
-          /* We don't have to test for the prvalue.*pm case here because its
-             result is a prvalue and therefore wouldn't get here, unless
-             follow_class_rvalue_addressing_path is TRUE, in which case
-             we want to keep going anyway. */
+          /* We don't have to test for the prvalue.*pm case here: it gets
+             here only if follow_class_rvalue_addressing_path is TRUE or if
+             its result is an xvalue (selection_from_prvalue_is_xvalue,
+             CWG 616), and in both cases we want to keep going. */
           traverse_expr(operand1, tblock);
           break;
         case eok_pm_points_to_field:
diff --git a/src/interpret.c b/src/interpret.c
index b06b001b3c..470dd4b303 100644
--- a/src/interpret.c
+++ b/src/interpret.c
@@ -23649,10 +23649,21 @@ after the constructor body has been interpreted.
       p_arg_ptr += 1;
       arg_size += 1;
     }  /* for */
-    if (dip->variant.constructor.value_initialization) {
-      /* If this is for value initialization, clear the storage first.
-         Do not, however, overwrite the first word (which may record the
-         inheritance hierarchy). */
+    if (!dip->variant.constructor.value_initialization) {
+      /* Nothing to do. */
+    } else if (!type_has_user_provided_default_constructor(class_type)) {
+      /* Value initialization of a class without a user-provided default
+         constructor zero-initializes the object before calling the
+         constructor, which need not initialize every subobject (e.g., a
+         member of a class whose implicit default constructor calls a
+         user-provided base class constructor).  Mark the subobjects as
+         initialized, so that reading them is valid. */
+      init_subobject_to_zero(ips, result_storage, class_type,
+                             complete_object);
+    } else {
+      /* Otherwise, the object is not zero-initialized, but clear the
+         storage anyway.  Do not, however, overwrite the first word (which
+         may record the inheritance hierarchy). */
       a_byte_count  n_class_bytes;
       a_boolean     dummy = TRUE;
       n_class_bytes = f_value_bytes_for_type(ips, class_type, &dummy);
@@ -31878,8 +31889,9 @@ the value representation of the integer value.
                 result_addr = *(a_constexpr_address*)opnd1_value;
               } else {
                 /* The first operand is a class rvalue: Create an address for
-                   it. */
-                mark_complete_object_initialized(opnd1_value);
+                   it.  Do not mark the object as fully initialized: since
+                   C++20, a constexpr constructor can leave members
+                   uninitialized, and reading those must be diagnosed. */
                 clear_address(&result_addr, opnd1_value);
                 result_addr.alloc_seq_number = ips->storage_stack.alloc_seq();
               }  /* if */
@@ -32003,8 +32015,9 @@ the value representation of the integer value.
                 result_addr = *(a_constexpr_address*)opnd1_value;
               } else {
                 /* The first operand is a class rvalue: Create an address for
-                   it. */
-                mark_complete_object_initialized(opnd1_value);
+                   it.  Do not mark the object as fully initialized: since
+                   C++20, a constexpr constructor can leave members
+                   uninitialized, and reading those must be diagnosed. */
                 clear_address(&result_addr, opnd1_value);
                 result_addr.alloc_seq_number = ips->storage_stack.alloc_seq();
               }  /* if */
diff --git a/src/pending_changes/gh-90-lifetime-extension-member-of-temporary.txt b/src/pending_changes/gh-90-lifetime-extension-member-of-temporary.txt
new file mode 100644
index 0000000000..7f959814f5
--- /dev/null
+++ b/src/pending_changes/gh-90-lifetime-extension-member-of-temporary.txt
@@ -0,0 +1,20 @@
+[GH #90]
+GNU and Clang C++ modes: lifetime extension through a member of a temporary
+
+When emulating GCC 9 or later or Clang 4 or later, selecting a member of a
+class prvalue now produces an xvalue (Core issue 616), as it already did in
+standard C++14 and later modes.  Binding a reference to the member now
+extends the lifetime of the whole temporary.  For example, with
+--g++ --gnu_version=150000:
+
+  struct A { int b; ~A(); };
+  const int &r = A().b;  // A() was previously destroyed here.
+
+Constant evaluation also no longer treats every member of a class prvalue
+as initialized when one is selected with "." or ".*".  Since C++20, a
+constexpr constructor can leave members uninitialized, and reading such a
+member is now diagnosed instead of producing an indeterminate value.  For
+example, with --c++20:
+
+  struct W { int n; constexpr W() {} };
+  static_assert(W().n == 0);  // Error: n is uninitialized.
diff --git a/src/pending_changes/gh-90-value-init-zeroed-members.txt b/src/pending_changes/gh-90-value-init-zeroed-members.txt
new file mode 100644
index 0000000000..83eb26ed53
--- /dev/null
+++ b/src/pending_changes/gh-90-value-init-zeroed-members.txt
@@ -0,0 +1,12 @@
+[GH #90]
+Constexpr reads of zero-initialized members after value initialization
+
+Value initialization of a class without a user-provided default constructor
+zero-initializes the object before calling the constructor.  During
+constant evaluation, the zeroed members were not treated as initialized, so
+reading one that the constructor does not set was rejected.  For example,
+with --c++20:
+
+  struct A { constexpr A() {} int x; };
+  struct B : A { int y; };
+  static_assert(B().x == 0);  // Previously rejected.
diff --git a/tests/expectations/edg_x86_64/imported.log b/tests/expectations/edg_x86_64/imported.log
index 2c384ac8c4..42bb45d78a 100644
--- a/tests/expectations/edg_x86_64/imported.log
+++ b/tests/expectations/edg_x86_64/imported.log
@@ -7077,7 +7077,6 @@ gnu/cpp/cpp2a/consteval25.sft.cpp:fp:-DTEST_NUMBER=1 --c++20:FAIL:
 gnu/cpp/cpp2a/consteval32.sft.cpp:fn:-DTEST_NUMBER=1 --c++20:FAIL:
 gnu/cpp/cpp2a/constexpr-99287.sft.cpp:fp:-DTEST_NUMBER=1 --c++20:FAIL:
 gnu/cpp/cpp2a/constexpr-dynamic13.sft.cpp:fp:-DTEST_NUMBER=1 --c++20:FAIL:
-gnu/cpp/cpp2a/constexpr-init18.sft.cpp:fp:-DTEST_NUMBER=1 --c++20:FAIL:
 gnu/cpp/cpp2a/constexpr-inst1.sft.cpp:fn:-DTEST_NUMBER=1 --c++14:FAIL:
 gnu/cpp/cpp2a/constexpr-inst2.sft.cpp:fp:-DTEST_NUMBER=1 --c++11:FAIL:
 gnu/cpp/cpp2a/constexpr-new11/test.mft.cpp:fp:-DTEST_NUMBER=1 --c++20:FAIL:
@@ -7757,7 +7756,6 @@ gnu/cpp/init/new22.sft.cpp:fn:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/new39.sft.cpp:rp:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/new40.sft.cpp:rp:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/null1.sft.cpp:fp:-DTEST_NUMBER=1 --c++11:FAIL:
-gnu/cpp/init/ref19.sft.cpp:rp:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/ref23.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/reference2.sft.cpp:fn:-DTEST_NUMBER=1:FAIL:
 gnu/cpp/init/self1.sft.cpp:fn:-DTEST_NUMBER=1 --c++11:FAIL:
diff --git a/tests/tests/cwg/.cwg616.rto/default.1.1.txt b/tests/tests/cwg/.cwg616.rto/default.1.1.txt
new file mode 100644
index 0000000000..b921d6c913
--- /dev/null
+++ b/tests/tests/cwg/.cwg616.rto/default.1.1.txt
@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=1 --c++14 Test_name.c
diff --git a/tests/tests/cwg/.cwg616.rto/default.2.1.txt b/tests/tests/cwg/.cwg616.rto/default.2.1.txt
new file mode 100644
index 0000000000..fe264f46a7
--- /dev/null
+++ b/tests/tests/cwg/.cwg616.rto/default.2.1.txt
@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=2 --c++14 --g++ --gnu_version=150000 Test_name.c
diff --git a/tests/tests/cwg/.cwg616.rto/default.3.1.txt b/tests/tests/cwg/.cwg616.rto/default.3.1.txt
new file mode 100644
index 0000000000..8d04c2fe9a
--- /dev/null
+++ b/tests/tests/cwg/.cwg616.rto/default.3.1.txt
@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=3 --c++14 --clang --clang_version=190100 Test_name.c
diff --git a/tests/tests/cwg/cwg616.sft.cpp b/tests/tests/cwg/cwg616.sft.cpp
new file mode 100644
index 0000000000..93b2f78782
--- /dev/null
+++ b/tests/tests/cwg/cwg616.sft.cpp
@@ -0,0 +1,14 @@
+//type:fp
+//options_all:--c++14
+//options::--g++ --gnu_version=150000:--clang --clang_version=190100
+template <class T> struct is_xvalue { static const bool value = false; };
+template <class T> struct is_xvalue<T &&> { static const bool value = true; };
+struct A { int b; };
+// Selecting a member of a class prvalue produces an xvalue.
+static_assert(is_xvalue<decltype((A().b))>::value, "");
+static_assert(is_xvalue<decltype((A().*&A::b))>::value, "");
+
+//cwg: 616
+//title: Definition of "indeterminate value"
+//meeting: Bristol 4/13
+//edg_status: Passes
diff --git a/tests/tests/imported/clang/cpp/CXX/dcl.decl/dcl.init/dcl.init.general/.p16-cxx20.rto/default.1.1.txt b/tests/tests/imported/clang/cpp/CXX/dcl.decl/dcl.init/dcl.init.general/.p16-cxx20.rto/default.1.1.txt
index b0262c2eb2..c3898711d9 100644
--- a/tests/tests/imported/clang/cpp/CXX/dcl.decl/dcl.init/dcl.init.general/.p16-cxx20.rto/default.1.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/dcl.decl/dcl.init/dcl.init.general/.p16-cxx20.rto/default.1.1.txt
@@ -1,11 +1,4 @@
 fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_version 999999 --c++20 Test_name.c
-"Test_name.c", line 16: error: expression must have a constant value
-      static_assert(B().x == 0);
-                    ^
-"Test_name.c", line 16: note: access to uninitialized object
-      static_assert(B().x == 0);
-                       ^
-
 "Test_name.c", line 27: error: class "P0960R3::A" has no suitable copy constructor
       A a1(va);
            ^
@@ -144,4 +137,4 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       D d8 = {vdd}; // expected-error {{no matching constructor for initialization of 'D'}}
               ^
 
-31 errors detected in the compilation of "Test_name.c".
+30 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.3.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.3.1.txt
index 23c8ab2e65..9db8cdbba4 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.3.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.3.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=3 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -635,4 +623,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-107 errors detected in the compilation of "Test_name.c".
+104 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.4.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.4.1.txt
index 1738068cba..9d2c6600d9 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.4.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.4.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=4 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -628,4 +616,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-107 errors detected in the compilation of "Test_name.c".
+104 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.5.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.5.1.txt
index 2311036199..86fe3e2a79 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.5.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.5.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=5 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -612,4 +600,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-103 errors detected in the compilation of "Test_name.c".
+100 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.6.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.6.1.txt
index 1781ea59f2..d6dd6d1ccd 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.6.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.6.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=6 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -600,4 +588,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-100 errors detected in the compilation of "Test_name.c".
+97 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.7.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.7.1.txt
index 0f65ec7845..d00f917a4b 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.7.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/default.7.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=7 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -600,4 +588,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-100 errors detected in the compilation of "Test_name.c".
+97 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.3.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.3.1.txt
index dd07f0d241..0237b2b78c 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.3.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.3.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=3 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -639,4 +627,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-107 errors detected in the compilation of "Test_name.c".
+104 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.4.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.4.1.txt
index b69b1360c8..299ea9b490 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.4.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.4.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=4 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -632,4 +620,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-107 errors detected in the compilation of "Test_name.c".
+104 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.5.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.5.1.txt
index b217fad05c..ba06bd79e4 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.5.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.5.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=5 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -616,4 +604,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-103 errors detected in the compilation of "Test_name.c".
+100 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.6.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.6.1.txt
index 99646fb4ff..81340c010d 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.6.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.6.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=6 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -604,4 +592,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-100 errors detected in the compilation of "Test_name.c".
+97 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.7.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.7.1.txt
index b8e9100361..b990a2e817 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.7.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32.7.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=7 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -604,4 +592,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-100 errors detected in the compilation of "Test_name.c".
+97 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.3.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.3.1.txt
index d0dcb23e1c..e5e25bd263 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.3.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.3.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=3 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -651,4 +639,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-110 errors detected in the compilation of "Test_name.c".
+107 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.4.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.4.1.txt
index 5fe2dded14..05fb67f79d 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.4.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.4.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=4 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -644,4 +632,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-110 errors detected in the compilation of "Test_name.c".
+107 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.5.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.5.1.txt
index 1713a4fe68..8c3b9e6f7e 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.5.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.5.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=5 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -620,4 +608,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-104 errors detected in the compilation of "Test_name.c".
+101 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.6.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.6.1.txt
index b5fddc6c90..181f32677d 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.6.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.6.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=6 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -608,4 +596,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-101 errors detected in the compilation of "Test_name.c".
+98 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.7.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.7.1.txt
index d639969d32..c677f6521e 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.7.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_32_cp.7.1.txt
@@ -47,18 +47,6 @@ fe_only -DTEST_NUMBER=7 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -608,4 +596,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-101 errors detected in the compilation of "Test_name.c".
+98 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.3.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.3.1.txt
index ceda8113e7..78fad00fa7 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.3.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.3.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=3 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -647,4 +635,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-110 errors detected in the compilation of "Test_name.c".
+107 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.4.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.4.1.txt
index e17ca6ed9b..afdfeedeb0 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.4.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.4.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=4 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -640,4 +628,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-110 errors detected in the compilation of "Test_name.c".
+107 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.5.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.5.1.txt
index fa617603ee..620594a888 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.5.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.5.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=5 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -616,4 +604,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-104 errors detected in the compilation of "Test_name.c".
+101 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.6.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.6.1.txt
index 7376d54ce6..b1f83c40fc 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.6.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.6.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=6 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -604,4 +592,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-101 errors detected in the compilation of "Test_name.c".
+98 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.7.1.txt b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.7.1.txt
index c247b4210d..4b40e10f9f 100644
--- a/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.7.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/drs/.cwg6xx.rto/edg_x86_64_cp.7.1.txt
@@ -43,18 +43,6 @@ fe_only -DTEST_NUMBER=7 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       const std::type_info &an2 = typeid(n + 1);
                             ^
 
-"Test_name.c", line 213: error: invalid redeclaration of type name "cwg616::T" (declared at line 212)
-    using T = decltype((static_cast<S&&>(s).n));
-          ^
-
-"Test_name.c", line 214: error: invalid redeclaration of type name "cwg616::T" (declared at line 213)
-    using T = decltype((f().n));
-          ^
-
-"Test_name.c", line 215: error: invalid redeclaration of type name "cwg616::T" (declared at line 214)
-    using T = decltype(S().*&S::n);
-          ^
-
 "Test_name.c", line 246: error: incomplete type "int []" is not allowed
       sizeof(x);
             ^
@@ -604,4 +592,4 @@ At end of source: error: expected a "}"
     constexpr int c = true || f();
                   ^
 
-101 errors detected in the compilation of "Test_name.c".
+98 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/default.2.1.txt b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/default.2.1.txt
index ad76d16536..8665cb9052 100644
--- a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/default.2.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/default.2.1.txt
@@ -365,6 +365,13 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr volatile S f() { return S(); } // cxx20-warning {{volatile-qualified return type 'volatile S' is deprecated}}
                          ^
 
+"Test_name.c", line 362: error: expression must have a constant value
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                  ^
+"Test_name.c", line 362: note: attempt to read from volatile storage
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                     ^
+
 "Test_name.c", line 363: error: expression must have a constant value
     static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
                   ^
@@ -1140,4 +1147,4 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr bool v8 = qv > (void*)&s.a;
                    ^
 
-93 errors detected in the compilation of "Test_name.c".
+94 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32.2.1.txt b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32.2.1.txt
index ad790e2063..b880afe7f7 100644
--- a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32.2.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32.2.1.txt
@@ -374,6 +374,13 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr volatile S f() { return S(); } // cxx20-warning {{volatile-qualified return type 'volatile S' is deprecated}}
                          ^
 
+"Test_name.c", line 362: error: expression must have a constant value
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                  ^
+"Test_name.c", line 362: note: attempt to read from volatile storage
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                     ^
+
 "Test_name.c", line 363: error: expression must have a constant value
     static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
                   ^
@@ -1156,4 +1163,4 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr intptr_t i = f((intptr_t)&foo - 10); // expected-error{{constexpr variable 'i' must be initialized by a constant expression}} \
                        ^
 
-95 errors detected in the compilation of "Test_name.c".
+96 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32_cp.2.1.txt b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32_cp.2.1.txt
index 41df730ffc..6cc6c6b4c2 100644
--- a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32_cp.2.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_32_cp.2.1.txt
@@ -362,6 +362,13 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr volatile S f() { return S(); } // cxx20-warning {{volatile-qualified return type 'volatile S' is deprecated}}
                          ^
 
+"Test_name.c", line 362: error: expression must have a constant value
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                  ^
+"Test_name.c", line 362: note: attempt to read from volatile storage
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                     ^
+
 "Test_name.c", line 363: error: expression must have a constant value
     static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
                   ^
@@ -1144,4 +1151,4 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr intptr_t i = f((intptr_t)&foo - 10); // expected-error{{constexpr variable 'i' must be initialized by a constant expression}} \
                        ^
 
-95 errors detected in the compilation of "Test_name.c".
+96 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_64_cp.2.1.txt b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_64_cp.2.1.txt
index 57fddb4333..c74f13ebbb 100644
--- a/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_64_cp.2.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/expr/expr.const/.p2-0x.rto/edg_x86_64_cp.2.1.txt
@@ -353,6 +353,13 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr volatile S f() { return S(); } // cxx20-warning {{volatile-qualified return type 'volatile S' is deprecated}}
                          ^
 
+"Test_name.c", line 362: error: expression must have a constant value
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                  ^
+"Test_name.c", line 362: note: attempt to read from volatile storage
+    static_assert(f().i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
+                     ^
+
 "Test_name.c", line 363: error: expression must have a constant value
     static_assert(((volatile const S&&)(S)0).i, ""); // expected-error {{constant expression}} expected-note {{read of volatile-qualified type}}
                   ^
@@ -1128,4 +1135,4 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
     constexpr bool v8 = qv > (void*)&s.a;
                    ^
 
-93 errors detected in the compilation of "Test_name.c".
+94 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/CXX/special/class.init/class.inhctor.init/.p1.rto/default.1.1.txt b/tests/tests/imported/clang/cpp/CXX/special/class.init/class.inhctor.init/.p1.rto/default.1.1.txt
index b861f68325..bad18c1ab6 100644
--- a/tests/tests/imported/clang/cpp/CXX/special/class.init/class.inhctor.init/.p1.rto/default.1.1.txt
+++ b/tests/tests/imported/clang/cpp/CXX/special/class.init/class.inhctor.init/.p1.rto/default.1.1.txt
@@ -38,17 +38,4 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
               ^
           detected during implicit generation of "vbase::D::B(int, int)" at line 89
 
-"Test_name.c", line 125: error: expression must have a constant value
-    constexpr Wrap2 b = {};
-                        ^
-"Test_name.c", line 117: note: access to uninitialized object
-      constexpr Param(int c) : n(4 * b.a + b.b + c) {}
-                                      ^
-"Test_name.c", line 123: note: called from:
-    constexpr Wrap1::Wrap1() : B(1) {}
-                                 ^
-"Test_name.c", line 112: note: called from:
-    struct Wrap2 : Wrap1 {};
-           ^
-
-10 errors detected in the compilation of "Test_name.c".
+9 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/default.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/default.1.1.txt
index bffb5a08a7..a9aa510486 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/default.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/default.1.1.txt
@@ -321,14 +321,14 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 586: note: access to uninitialized object
     static_assert(Y(0,0).z1.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: error: expression must have a constant value
     static_assert(Y(0,0).z3.n == 0);
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: note: access to uninitialized object
     static_assert(Y(0,0).z3.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 589: error: expression must have a constant value
     static_assert(copy(Y(0,0)).z2.n == 0);
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32.1.1.txt
index 5de6cdae54..adc5caf7af 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32.1.1.txt
@@ -321,14 +321,14 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 586: note: access to uninitialized object
     static_assert(Y(0,0).z1.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: error: expression must have a constant value
     static_assert(Y(0,0).z3.n == 0);
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: note: access to uninitialized object
     static_assert(Y(0,0).z3.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 589: error: expression must have a constant value
     static_assert(copy(Y(0,0)).z2.n == 0);
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32_cp.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32_cp.1.1.txt
index cc21dc7a33..674a683226 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32_cp.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_32_cp.1.1.txt
@@ -335,14 +335,14 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 586: note: access to uninitialized object
     static_assert(Y(0,0).z1.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: error: expression must have a constant value
     static_assert(Y(0,0).z3.n == 0);
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: note: access to uninitialized object
     static_assert(Y(0,0).z3.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 589: error: expression must have a constant value
     static_assert(copy(Y(0,0)).z2.n == 0);
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_64_cp.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_64_cp.1.1.txt
index cb6067532a..227b3e7bd3 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_64_cp.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constant-expression-cxx2a.rto/edg_x86_64_cp.1.1.txt
@@ -335,14 +335,14 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 586: note: access to uninitialized object
     static_assert(Y(0,0).z1.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: error: expression must have a constant value
     static_assert(Y(0,0).z3.n == 0);
                   ^
 "SemaCXX/constant-expression-cxx2a.cpp", line 587: note: access to uninitialized object
     static_assert(Y(0,0).z3.n == 0);
-                        ^
+                           ^
 
 "SemaCXX/constant-expression-cxx2a.cpp", line 589: error: expression must have a constant value
     static_assert(copy(Y(0,0)).z2.n == 0);
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.1.1.txt
index dbe90c1c66..060b495068 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.1.1.txt
@@ -30,16 +30,6 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   struct B { // expected-note {{in call to 'A()'}}
          ^
 
-"Test_name.c", line 22: error: expression must have a constant value
-  constexpr B b2 = B(); // ok
-                   ^
-"Test_name.c", line 7: note: access to uninitialized object
-    constexpr A() : a(b + 1), b(a + 1) {} // expected-note 5{{outside its lifetime}}
-                      ^
-"Test_name.c", line 11: note: called from:
-  struct B { // expected-note {{in call to 'A()'}}
-         ^
-
 "Test_name.c", line 30: error: const variable "c1" requires an initializer -- class "C" has no user-provided default constructor
   constexpr C c1; // expected-error {{without a user-provided default constructor}}
                 ^
@@ -67,16 +57,6 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
                 ^
 
-"Test_name.c", line 47: error: expression must have a constant value
-  constexpr E e2 = E();
-                   ^
-"Test_name.c", line 7: note: access to uninitialized object
-    constexpr A() : a(b + 1), b(a + 1) {} // expected-note 5{{outside its lifetime}}
-                      ^
-"Test_name.c", line 46: note: called from:
-  constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
-                ^
-
 "Test_name.c", line 59: error: incomplete type "InvalidDeclInsideConstExpr::i<1>" is not allowed
     i<x> g; // expected-error {{implicit instantiation of undefined template 'InvalidDeclInsideConstExpr::i<1>'}}
          ^
@@ -118,4 +98,4 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
               ^
 
-12 errors detected in the compilation of "Test_name.c".
+10 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.2.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.2.1.txt
index 413803bd7f..20da054180 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.2.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.constexpr-value-init.rto/default.2.1.txt
@@ -30,16 +30,6 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   struct B { // expected-note {{in call to 'A()'}}
          ^
 
-"Test_name.c", line 22: error: expression must have a constant value
-  constexpr B b2 = B(); // ok
-                   ^
-"Test_name.c", line 7: note: access to uninitialized object
-    constexpr A() : a(b + 1), b(a + 1) {} // expected-note 5{{outside its lifetime}}
-                      ^
-"Test_name.c", line 11: note: called from:
-  struct B { // expected-note {{in call to 'A()'}}
-         ^
-
 "Test_name.c", line 30: error: const variable "c1" requires an initializer -- class "C" has no user-provided default constructor
   constexpr C c1; // expected-error {{without a user-provided default constructor}}
                 ^
@@ -67,16 +57,6 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
                 ^
 
-"Test_name.c", line 47: error: expression must have a constant value
-  constexpr E e2 = E();
-                   ^
-"Test_name.c", line 7: note: access to uninitialized object
-    constexpr A() : a(b + 1), b(a + 1) {} // expected-note 5{{outside its lifetime}}
-                      ^
-"Test_name.c", line 46: note: called from:
-  constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
-                ^
-
 "Test_name.c", line 59: error: incomplete type "InvalidDeclInsideConstExpr::i<1>" is not allowed
     i<x> g; // expected-error {{implicit instantiation of undefined template 'InvalidDeclInsideConstExpr::i<1>'}}
          ^
@@ -118,4 +98,4 @@ fe_only -DTEST_NUMBER=2 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
   constexpr E e1; // expected-error {{constant expression}} expected-note {{in call to 'E()'}}
               ^
 
-12 errors detected in the compilation of "Test_name.c".
+10 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/clang/cpp/SemaCXX/.cxx2c-placeholder-vars.rto/default.1.1.txt b/tests/tests/imported/clang/cpp/SemaCXX/.cxx2c-placeholder-vars.rto/default.1.1.txt
index 277238cca3..67ead7a95a 100644
--- a/tests/tests/imported/clang/cpp/SemaCXX/.cxx2c-placeholder-vars.rto/default.1.1.txt
+++ b/tests/tests/imported/clang/cpp/SemaCXX/.cxx2c-placeholder-vars.rto/default.1.1.txt
@@ -267,10 +267,6 @@ fe_only -DTEST_NUMBER=1 --clang -tused -e 200 --no_wrap_diagnostics --clang_vers
       int _, _; // expected-warning {{placeholder variables are incompatible with C++ standards before C++2c}} \
              ^
 
-"Test_name.c", line 236: warning: expression has no effect
-      S{}._; // expected-error {{ambiguous reference to placeholder '_', which is defined multiple times}}
-      ^
-
 "Test_name.c", line 235: warning: variable "s" was declared but never referenced
       S s{._ =0}; // expected-error {{ambiguous reference to placeholder '_', which is defined multiple times}}
         ^
diff --git a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/default.1.1.txt b/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/default.1.1.txt
index fe3eb50e9e..1026717d8f 100644
--- a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/default.1.1.txt
+++ b/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/default.1.1.txt
@@ -1,9 +1,9 @@
 fe_only -DTEST_NUMBER=1 --gnu_version=999999 -tused -e 200 --no_wrap --no_wrap_diagnostics --c++11 Test_name.c
-"Test_name.c", line 12: error: static assertion failed with ""
+"Test_name.c", line 12: error: expression must have a constant value
   static_assert(test(0).m == 0, "");
-  ^
-"Test_name.c", line 12: note: the final comparison was -48039863565308959547770532813896688677 == 0
+                ^
+"Test_name.c", line 12: note: access to uninitialized object
   static_assert(test(0).m == 0, "");
-                          ^
+                       ^
 
 1 error detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32.1.1.txt b/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32.1.1.txt
deleted file mode 100644
index 439ecda17a..0000000000
--- a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32.1.1.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-fe_only -DTEST_NUMBER=1 --gnu_version=999999 -tused -e 200 --no_wrap --no_wrap_diagnostics --c++11 Test_name.c
-"Test_name.c", line 12: error: static assertion failed with ""
-  static_assert(test(0).m == 0, "");
-  ^
-"Test_name.c", line 12: note: the final comparison was -2604246222170760229 == 0
-  static_assert(test(0).m == 0, "");
-                          ^
-
-1 error detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32_cp.1.1.txt b/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32_cp.1.1.txt
deleted file mode 100644
index 439ecda17a..0000000000
--- a/tests/tests/imported/gnu/cpp/cpp0x/.constexpr-delegating3.rto/edg_x86_32_cp.1.1.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-fe_only -DTEST_NUMBER=1 --gnu_version=999999 -tused -e 200 --no_wrap --no_wrap_diagnostics --c++11 Test_name.c
-"Test_name.c", line 12: error: static assertion failed with ""
-  static_assert(test(0).m == 0, "");
-  ^
-"Test_name.c", line 12: note: the final comparison was -2604246222170760229 == 0
-  static_assert(test(0).m == 0, "");
-                          ^
-
-1 error detected in the compilation of "Test_name.c".
diff --git a/tests/tests/imported/gnu/cpp/cpp2a/.constexpr-init18.rto/default.1.1.txt b/tests/tests/imported/gnu/cpp/cpp2a/.constexpr-init18.rto/default.1.1.txt
index 73ead29a37..2ed4eaf390 100644
--- a/tests/tests/imported/gnu/cpp/cpp2a/.constexpr-init18.rto/default.1.1.txt
+++ b/tests/tests/imported/gnu/cpp/cpp2a/.constexpr-init18.rto/default.1.1.txt
@@ -1,16 +1 @@
 fe_only -DTEST_NUMBER=1 --gnu_version=999999 -tused -e 200 --no_wrap --no_wrap_diagnostics --c++20 Test_name.c
-"Test_name.c", line 14: error: initialization is not constant
-  constexpr t<1> h1;
-                 ^
-"Test_name.c", line 14: note: access to uninitialized subobject (member "e::w")
-  constexpr t<1> h1;
-                 ^
-
-"Test_name.c", line 17: error: initialization is not constant
-  constexpr t<42> h2;
-                  ^
-"Test_name.c", line 17: note: access to uninitialized subobject (member "e::w")
-  constexpr t<42> h2;
-                  ^
-
-2 errors detected in the compilation of "Test_name.c".
diff --git a/tests/tests/regressions/.gh-90-old-modes.rto/default.1.1.txt b/tests/tests/regressions/.gh-90-old-modes.rto/default.1.1.txt
new file mode 100644
index 0000000000..38d19b508a
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-old-modes.rto/default.1.1.txt
@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=1 --c++14 --g++ --gnu_version=80300 Test_name.c
diff --git a/tests/tests/regressions/.gh-90-old-modes.rto/default.2.1.txt b/tests/tests/regressions/.gh-90-old-modes.rto/default.2.1.txt
new file mode 100644
index 0000000000..fdbcccb1e7
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-old-modes.rto/default.2.1.txt
@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=2 --c++14 --clang --clang_version=30900 Test_name.c
diff --git a/tests/tests/regressions/.gh-90-warn.rto/default.1.1.txt b/tests/tests/regressions/.gh-90-warn.rto/default.1.1.txt
new file mode 100644
index 0000000000..14477c2b8b
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-warn.rto/default.1.1.txt
@@ -0,0 +1,13 @@
+fe_only -DTEST_NUMBER=1 --c++20 Test_name.c
+"Test_name.c", line 13: warning: returning reference to local temporary
+  const int &f1() { return A().b; }                            // Warning.
+                           ^
+
+"Test_name.c", line 14: warning: returning pointer to local temporary
+  const int *f2() { return &static_cast<const int &>(A().b); } // Warning.
+                           ^
+
+"Test_name.c", line 15: warning: returning reference to local temporary
+  int &&f3() { return static_cast<A &&>(A()).b; }              // Warning.
+                      ^
+
diff --git a/tests/tests/regressions/.gh-90-warn.rto/default.2.1.txt b/tests/tests/regressions/.gh-90-warn.rto/default.2.1.txt
new file mode 100644
index 0000000000..c31dbdcd95
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-warn.rto/default.2.1.txt
@@ -0,0 +1,13 @@
+fe_only -DTEST_NUMBER=2 --c++20 --g++ --gnu_version=150000 Test_name.c
+"Test_name.c", line 13: warning: returning reference to local temporary
+  const int &f1() { return A().b; }                            // Warning.
+                           ^
+
+"Test_name.c", line 14: warning: returning pointer to local temporary
+  const int *f2() { return &static_cast<const int &>(A().b); } // Warning.
+                           ^
+
+"Test_name.c", line 15: warning: returning reference to local temporary
+  int &&f3() { return static_cast<A &&>(A()).b; }              // Warning.
+                      ^
+
diff --git a/tests/tests/regressions/.gh-90-warn.rto/default.3.1.txt b/tests/tests/regressions/.gh-90-warn.rto/default.3.1.txt
new file mode 100644
index 0000000000..cfb8e39f76
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-warn.rto/default.3.1.txt
@@ -0,0 +1,13 @@
+fe_only -DTEST_NUMBER=3 --c++20 --g++ --gnu_version=80000 Test_name.c
+"Test_name.c", line 13: warning: returning reference to local temporary
+  const int &f1() { return A().b; }                            // Warning.
+                           ^
+
+"Test_name.c", line 14: warning: returning pointer to local temporary
+  const int *f2() { return &static_cast<const int &>(A().b); } // Warning.
+                           ^
+
+"Test_name.c", line 15: warning: returning reference to local temporary
+  int &&f3() { return static_cast<A &&>(A()).b; }              // Warning.
+                      ^
+
diff --git a/tests/tests/regressions/.gh-90-warn.rto/default.4.1.txt b/tests/tests/regressions/.gh-90-warn.rto/default.4.1.txt
new file mode 100644
index 0000000000..10046374bd
--- /dev/null
+++ b/tests/tests/regressions/.gh-90-warn.rto/default.4.1.txt
@@ -0,0 +1,13 @@
+fe_only -DTEST_NUMBER=4 --c++20 --clang --clang_version=190100 Test_name.c
+"Test_name.c", line 13: warning: returning reference to local temporary
+  const int &f1() { return A().b; }                            // Warning.
+                           ^
+
+"Test_name.c", line 14: warning: returning pointer to local temporary
+  const int *f2() { return &static_cast<const int &>(A().b); } // Warning.
+                           ^
+
+"Test_name.c", line 15: warning: returning reference to local temporary
+  int &&f3() { return static_cast<A &&>(A()).b; }              // Warning.
+                      ^
+
diff --git a/tests/tests/regressions/.gh-90.rto/default.1.1.txt b/tests/tests/regressions/.gh-90.rto/default.1.1.txt
new file mode 100644
index 0000000000..30e4550776
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.1.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=1 --c++14 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.1.2.txt b/tests/tests/regressions/.gh-90.rto/default.1.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.1.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/.gh-90.rto/default.2.1.txt b/tests/tests/regressions/.gh-90.rto/default.2.1.txt
new file mode 100644
index 0000000000..b424c530a9
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.2.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=2 --c++20 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.2.2.txt b/tests/tests/regressions/.gh-90.rto/default.2.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.2.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/.gh-90.rto/default.3.1.txt b/tests/tests/regressions/.gh-90.rto/default.3.1.txt
new file mode 100644
index 0000000000..6a31461038
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.3.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=3 --c++14 --g++ --gnu_version=90000 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.3.2.txt b/tests/tests/regressions/.gh-90.rto/default.3.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.3.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/.gh-90.rto/default.4.1.txt b/tests/tests/regressions/.gh-90.rto/default.4.1.txt
new file mode 100644
index 0000000000..582096beac
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.4.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=4 --c++20 --g++ --gnu_version=150000 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.4.2.txt b/tests/tests/regressions/.gh-90.rto/default.4.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.4.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/.gh-90.rto/default.5.1.txt b/tests/tests/regressions/.gh-90.rto/default.5.1.txt
new file mode 100644
index 0000000000..7a32723bd5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.5.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=5 --c++14 --clang --clang_version=40000 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.5.2.txt b/tests/tests/regressions/.gh-90.rto/default.5.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.5.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/.gh-90.rto/default.6.1.txt b/tests/tests/regressions/.gh-90.rto/default.6.1.txt
new file mode 100644
index 0000000000..36d2f6899d
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.6.1.txt
@@ -0,0 +1 @@
+eccp -DTEST_NUMBER=6 --c++20 --clang --clang_version=190100 Test_name.c
diff --git a/tests/tests/regressions/.gh-90.rto/default.6.2.txt b/tests/tests/regressions/.gh-90.rto/default.6.2.txt
new file mode 100644
index 0000000000..ff2642c6d5
--- /dev/null
+++ b/tests/tests/regressions/.gh-90.rto/default.6.2.txt
@@ -0,0 +1 @@
+./a.out
diff --git a/tests/tests/regressions/gh-90-old-modes.sft.cpp b/tests/tests/regressions/gh-90-old-modes.sft.cpp
new file mode 100644
index 0000000000..ec95e6f196
--- /dev/null
+++ b/tests/tests/regressions/gh-90-old-modes.sft.cpp
@@ -0,0 +1,10 @@
+//type:fp
+//options_all:--c++14
+//options:--g++ --gnu_version=80300:--clang --clang_version=30900
+// GCC before 9 and Clang before 4 do not implement Core issue 616: selecting
+// a member of a class prvalue still produces a prvalue (the C++11 rule).
+template <class T> struct is_prvalue { static const bool value = true; };
+template <class T> struct is_prvalue<T &> { static const bool value = false; };
+template <class T> struct is_prvalue<T &&> { static const bool value = false; };
+struct A { int b; };
+static_assert(is_prvalue<decltype((A().b))>::value, "");
diff --git a/tests/tests/regressions/gh-90-warn.sft.cpp b/tests/tests/regressions/gh-90-warn.sft.cpp
new file mode 100644
index 0000000000..476bdbbae9
--- /dev/null
+++ b/tests/tests/regressions/gh-90-warn.sft.cpp
@@ -0,0 +1,21 @@
+//type:fp
+//options_all:--c++20
+//options::--g++ --gnu_version=150000:--g++ --gnu_version=80000:--clang --clang_version=190100
+
+// Returning a reference or pointer into a member of a class prvalue returns
+// a reference into a local temporary.  When "A().b" is an xvalue (Core issue
+// 616), that is still diagnosed, as it is when "A().b" is a prvalue.
+
+struct A { int b; ~A(); };
+struct R { int &r; int *p; };
+int g;
+
+const int &f1() { return A().b; }                            // Warning.
+const int *f2() { return &static_cast<const int &>(A().b); } // Warning.
+int &&f3() { return static_cast<A &&>(A()).b; }              // Warning.
+
+// No warnings for these.
+const int &n1() { return R{g, &g}.r; }
+const int &n2() { return *R{g, &g}.p; }
+const int &n3(A &&a) { return static_cast<A &&>(a).b; }
+int n4() { return A().b; }
diff --git a/tests/tests/regressions/gh-90.sft.cpp b/tests/tests/regressions/gh-90.sft.cpp
new file mode 100644
index 0000000000..d1b2d17bbc
--- /dev/null
+++ b/tests/tests/regressions/gh-90.sft.cpp
@@ -0,0 +1,53 @@
+//type:rp
+//options:--c++14:--c++20:--c++14 --g++ --gnu_version=90000:--c++20 --g++ --gnu_version=150000:--c++14 --clang --clang_version=40000:--c++20 --clang --clang_version=190100
+
+// Binding a reference to a subobject of a temporary extends the lifetime of
+// the whole temporary (N4140 [class.temporary]/5).  In GNU and Clang modes,
+// "A().b" was a prvalue (the C++11 rule), so the reference was bound to a
+// copy of the member and the A temporary was destroyed at the end of the
+// full-expression.  GCC 9 and Clang 4 implement Core issue 616, under which
+// "A().b" is an xvalue that designates the member of the temporary.
+
+int d;
+struct A {
+  int b;
+  int i[2];
+  ~A() { ++d; }
+};
+
+int failures;
+void check(bool ok) { if (!ok) ++failures; }
+
+int main() {
+  {
+    const int &r = A().b;
+    check(d == 0);   // Previously failed in GNU and Clang modes.
+  }
+  check(d == 1);
+  d = 0;
+  {
+    int &&r = A().b;
+    check(d == 0);   // Previously failed in GNU and Clang modes.
+  }
+  check(d == 1);
+  d = 0;
+  {
+    const int &r = A().i[0];
+    check(d == 0);
+  }
+  check(d == 1);
+  d = 0;
+  {
+    int A::*pm = &A::b;
+    const int &r = A().*pm;
+    check(d == 0);
+  }
+  check(d == 1);
+  d = 0;
+  {
+    int (&&r)[2] = A().i;
+    check(d == 0);
+  }
+  check(d == 1);
+  return failures;
+}