[clang] [clang][bytecode] Reject constexpr-unknown values in CheckStore (PR #136279)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/136279

None

>From 7cfafd2b9ee2bb357a6e2ff0f9cacde6f1c1725b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 18 Apr 2025 10:23:40 +0200
Subject: [PATCH] [clang][bytecode] Reject constexpr-unknown values in
 CheckStore

---
 clang/lib/AST/ByteCode/Interp.cpp | 2 ++
 clang/test/CodeGen/p0963r3.cpp    | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 4625154ac353d..b755a072fec88 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -790,6 +790,8 @@ bool CheckStore(InterpState &S, CodePtr OpPC, const Pointer &Ptr) {
     return false;
   if (!CheckConst(S, OpPC, Ptr))
     return false;
+  if (!S.inConstantContext() && isConstexprUnknown(Ptr))
+    return false;
   return true;
 }
 
diff --git a/clang/test/CodeGen/p0963r3.cpp b/clang/test/CodeGen/p0963r3.cpp
index 4a5e6c3f5d751..65d33397e6173 100644
--- a/clang/test/CodeGen/p0963r3.cpp
+++ b/clang/test/CodeGen/p0963r3.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -std=c++2c -verify -emit-llvm -triple=x86_64-pc-linux-gnu %s -o - | FileCheck %s
-// RUN: %clang_cc1 -std=c++2c -verify -fsyntax-only -fexperimental-new-constant-interpreter -triple=x86_64-pc-linux-gnu %s
+// RUN: %clang_cc1 -std=c++2c -verify -emit-llvm -triple=x86_64-pc-linux-gnu %s -o -                                         | FileCheck %s
+// RUN: %clang_cc1 -std=c++2c -verify -emit-llvm -triple=x86_64-pc-linux-gnu %s -o - -fexperimental-new-constant-interpreter | FileCheck %s
 // expected-no-diagnostics
 
 namespace std {