[clang] [clang] Fix clang++ crash on assertions when compiling source (PR #70594)

[Rajveer Singh Bharadwaj via cfe-commits]

https://github.com/Rajveer100 updated https://github.com/llvm/llvm-project/pull/70594

>From 1923c212515033dbb92f09c6d11cd2b679261459 Mon Sep 17 00:00:00 2001
From: Rajveer <rajveer.developer at icloud.com>
Date: Sun, 29 Oct 2023 18:37:17 +0530
Subject: [PATCH] [clang] Fix a crash in debug mode

Resolves Issue #35603

This bug was caused due to the assertions being too strict,
loosened by stripping qualifiers from the base class but not
from the type of the initializer.

Added Release Notes for the same.
---
 clang/docs/ReleaseNotes.rst    |  3 +++
 clang/lib/AST/ExprConstant.cpp |  2 +-
 clang/test/Sema/GH35603.cpp    | 19 +++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/Sema/GH35603.cpp

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 2595737e8b3b1..25cdc31b0caa6 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -670,6 +670,9 @@ Bug Fixes to C++ Support
   default initializing a base class in a constant expression context. Fixes:
   (`#69890 <https://github.com/llvm/llvm-project/issues/69890>`_)
 
+- Fix crash when inheriting from a cv-qualified type. Fixes:
+  (`#35603 <https://github.com/llvm/llvm-project/issues/35603>`_)
+
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed an import failure of recursive friend class template.
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 5947805f9576f..07f0a12385b46 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -6431,7 +6431,7 @@ static bool HandleConstructorCall(const Expr *E, const LValue &This,
       // Non-virtual base classes are initialized in the order in the class
       // definition. We have already checked for virtual base classes.
       assert(!BaseIt->isVirtual() && "virtual base for literal type");
-      assert(Info.Ctx.hasSameType(BaseIt->getType(), BaseType) &&
+      assert(Info.Ctx.hasSameUnqualifiedType(BaseIt->getType(), BaseType) &&
              "base class initializers not in expected order");
       ++BaseIt;
 #endif
diff --git a/clang/test/Sema/GH35603.cpp b/clang/test/Sema/GH35603.cpp
new file mode 100644
index 0000000000000..853552108ec2b
--- /dev/null
+++ b/clang/test/Sema/GH35603.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 %s -verify
+// RUN: %clang_cc1 -fsyntax-only -std=c++23 %s -verify
+
+// expected-no-diagnostics
+
+struct A {};
+using CA = const A;
+
+struct S1 : CA {
+  constexpr S1() : CA() {}
+};
+
+struct S2 : A {
+  constexpr S2() : CA() {}
+};
+
+struct S3 : CA {
+  constexpr S3() : A() {}
+};