[Clang] Fix a regression introduced by llvm#138518

We did not handle the case where a variable could be
initialized by a CXXParenListInitExpr.

Author: cor3ntin

clang/lib/Sema/SemaDecl.cpp

@@ -13783,9 +13783,11 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
         VDecl->getLocation(), DirectInit, Init);
 
     MultiExprArg Args = Init;
-    if (CXXDirectInit)
-      Args = MultiExprArg(CXXDirectInit->getExprs(),
-                          CXXDirectInit->getNumExprs());
+    if (auto *CXXDirectInit = dyn_cast<ParenListExpr>(Init))
+      Args =
+          MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
+    else if (auto *CXXDirectInit = dyn_cast<CXXParenListInitExpr>(Init))
+      Args = CXXDirectInit->getInitExprs();
 
     // Try to correct any TypoExprs in the initialization arguments.
     for (size_t Idx = 0; Idx < Args.size(); ++Idx) {

clang/test/SemaCXX/paren-list-agg-init.cpp

@@ -403,3 +403,25 @@ void test() {
     S<int>{}.f(); // beforecxx20-note {{requested here}}
 }
 }
+
+namespace GH72880_regression {
+struct E {
+    int i = 42;
+};
+struct G {
+  E e;
+};
+template <typename>
+struct Test {
+  void f() {
+    constexpr E e;
+    //FIXME: We should only warn one
+    constexpr G g(e); // beforecxx20-warning 2{{C++20 extension}}
+    static_assert(g.e.i == 42);
+  }
+};
+void test() {
+    Test<int>{}.f(); // beforecxx20-note {{requested here}}
+}
+
+}