[clang] [clang] fix sema init crashing on initialization sequences (PR #98102)

[Yuxuan Chen via cfe-commits]

https://github.com/yuxuanchen1997 updated https://github.com/llvm/llvm-project/pull/98102

>From 097881dcd14d44e97e526de86dc348e7a4e5a2e6 Mon Sep 17 00:00:00 2001
From: Yuxuan Chen <yuxuanchen1997 at outlook.com>
Date: Mon, 8 Jul 2024 18:16:17 -0700
Subject: [PATCH 1/2] [clang] fix sema init crash for not checking a ExprResult

---
 clang/lib/Sema/SemaInit.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 41753a1661ace..a27ed02fc73b8 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -5576,6 +5576,10 @@ static void TryOrBuildParenListInitialization(
       ExprResult ER;
       ER = IS.Perform(S, SubEntity, SubKind,
                       Arg ? MultiExprArg(Arg) : std::nullopt);
+
+      if (ER.isInvalid())
+        return false;
+
       if (InitExpr)
         *InitExpr = ER.get();
       else

>From 4c2b881257094a503ece9528bff045a312086988 Mon Sep 17 00:00:00 2001
From: Yuxuan Chen <ych at meta.com>
Date: Tue, 9 Jul 2024 19:52:34 -0700
Subject: [PATCH 2/2] Add a crash-on-valid unit test

---
 clang/docs/ReleaseNotes.rst    |  2 ++
 clang/test/SemaCXX/pr98102.cpp | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 clang/test/SemaCXX/pr98102.cpp

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index d0930ccfc603b..cfec1cd14a6fc 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -813,6 +813,8 @@ Bug Fixes in This Version
 
 - Fixed `static_cast` to array of unknown bound. Fixes (#GH62863).
 
+- Fixed Clang crashing when failing to perform some C++ Initialization Sequences. (#GH98102)
+
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/clang/test/SemaCXX/pr98102.cpp b/clang/test/SemaCXX/pr98102.cpp
new file mode 100644
index 0000000000000..9281279c1848c
--- /dev/null
+++ b/clang/test/SemaCXX/pr98102.cpp
@@ -0,0 +1,33 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 %s
+// expected-no-diagnostics
+
+template <bool v>
+struct BC {
+  static constexpr bool value = v;
+};
+
+template <typename T, typename Arg>
+struct Constructible : BC<__is_constructible(T, Arg)> {};
+
+template <typename T>
+using Requires = T::value;
+
+template <typename T>
+struct optional {
+  template <typename U, Requires<Constructible<T, U>> = true>
+  optional(U) {}
+};
+
+struct MO {};
+struct S : MO {};
+struct TB {
+  TB(optional<S>) {}
+};
+
+class TD : TB, MO {
+  using TB::TB;
+};
+
+void foo() {
+  static_assert(Constructible<TD, TD>::value);
+}