[clang] [Clang] Fix a regression introduced by #138518 (PR #141342)

[via cfe-commits]

https://github.com/cor3ntin updated https://github.com/llvm/llvm-project/pull/141342

>From c0603457eb734d8a0aeb8a5c3cf131485116e303 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Sat, 24 May 2025 12:37:02 +0200
Subject: [PATCH 1/4] [Clang] Fix a regression introduced by #138518

We did not handle the case where a variable could be
initialized by a CXXParenListInitExpr.
---
 clang/lib/Sema/SemaDecl.cpp                |  8 +++++---
 clang/test/SemaCXX/paren-list-agg-init.cpp | 22 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 90525f386468a..401d1f34f70c0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/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) {
diff --git a/clang/test/SemaCXX/paren-list-agg-init.cpp b/clang/test/SemaCXX/paren-list-agg-init.cpp
index ba7dffdc1af9f..680fdcdbe7b1c 100644
--- a/clang/test/SemaCXX/paren-list-agg-init.cpp
+++ b/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}}
+}
+
+}

>From 1ac18712bca2076a9073b94a11133a3d88f05a99 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Tue, 27 May 2025 17:48:58 +0200
Subject: [PATCH 2/4] cleanup

---
 clang/lib/Sema/SemaDecl.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 401d1f34f70c0..cac0eecc5f83a 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13775,7 +13775,6 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   }
 
   // Perform the initialization.
-  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
   bool IsParenListInit = false;
   if (!VDecl->isInvalidDecl()) {
     InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);

>From b2fe02ed27a718ba3d0540d46dbdc3f95b1a786a Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Tue, 27 May 2025 19:24:44 +0200
Subject: [PATCH 3/4] Revert "cleanup"

This reverts commit 1ac18712bca2076a9073b94a11133a3d88f05a99.
---
 clang/lib/Sema/SemaDecl.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index cac0eecc5f83a..401d1f34f70c0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13775,6 +13775,7 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   }
 
   // Perform the initialization.
+  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
   bool IsParenListInit = false;
   if (!VDecl->isInvalidDecl()) {
     InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);

>From acaedbc5e7f57890884cff23ad7478e9f31d5450 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinjabot at gmail.com>
Date: Tue, 27 May 2025 19:32:17 +0200
Subject: [PATCH 4/4] Track that we are initializing from a paren list expr

---
 clang/lib/Sema/SemaDecl.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 401d1f34f70c0..6b42c9161935f 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13775,7 +13775,7 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   }
 
   // Perform the initialization.
-  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
+  bool InitializedFromParenListExpr = false;
   bool IsParenListInit = false;
   if (!VDecl->isInvalidDecl()) {
     InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
@@ -13783,11 +13783,14 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
         VDecl->getLocation(), DirectInit, Init);
 
     MultiExprArg Args = Init;
-    if (auto *CXXDirectInit = dyn_cast<ParenListExpr>(Init))
+    if (auto *CXXDirectInit = dyn_cast<ParenListExpr>(Init)) {
       Args =
           MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
-    else if (auto *CXXDirectInit = dyn_cast<CXXParenListInitExpr>(Init))
+      InitializedFromParenListExpr = true;
+    } else if (auto *CXXDirectInit = dyn_cast<CXXParenListInitExpr>(Init)) {
       Args = CXXDirectInit->getInitExprs();
+      InitializedFromParenListExpr = true;
+    }
 
     // Try to correct any TypoExprs in the initialization arguments.
     for (size_t Idx = 0; Idx < Args.size(); ++Idx) {
@@ -14088,7 +14091,7 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
   // The form of initialization (using parentheses or '=') is generally
   // insignificant, but does matter when the entity being initialized has a
   // class type.
-  if (CXXDirectInit) {
+  if (InitializedFromParenListExpr) {
     assert(DirectInit && "Call-style initializer must be direct init.");
     VDecl->setInitStyle(IsParenListInit ? VarDecl::ParenListInit
                                         : VarDecl::CallInit);