[clang] [clang][bytecode] Check for dummy pointers when calling pseudo dtors (PR #137437)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/137437

None

>From 043c655ece82e3a167745000a102911cee56143f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Sat, 26 Apr 2025 04:53:56 +0200
Subject: [PATCH] [clang][bytecode] Check for dummy pointers when calling
 pseudo dtors

---
 clang/lib/AST/ByteCode/Interp.cpp     | 3 +--
 clang/lib/AST/ByteCode/Interp.h       | 2 ++
 clang/test/AST/ByteCode/lifetimes.cpp | 6 ++++++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 0cb6d870b8cc7..37111343178dd 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1078,8 +1078,7 @@ bool CheckDummy(InterpState &S, CodePtr OpPC, const Pointer &Ptr,
   if (AK == AK_Read || AK == AK_Increment || AK == AK_Decrement)
     return diagnoseUnknownDecl(S, OpPC, D);
 
-  assert(AK == AK_Assign);
-  if (S.getLangOpts().CPlusPlus14) {
+  if (AK == AK_Destroy || S.getLangOpts().CPlusPlus14) {
     const SourceInfo &E = S.Current->getSource(OpPC);
     S.FFDiag(E, diag::note_constexpr_modify_global);
   }
diff --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h
index c1970f064cef5..91864ba452135 100644
--- a/clang/lib/AST/ByteCode/Interp.h
+++ b/clang/lib/AST/ByteCode/Interp.h
@@ -1320,6 +1320,8 @@ bool GetLocal(InterpState &S, CodePtr OpPC, uint32_t I) {
 
 static inline bool Kill(InterpState &S, CodePtr OpPC) {
   const auto &Ptr = S.Stk.pop<Pointer>();
+  if (!CheckDummy(S, OpPC, Ptr, AK_Destroy))
+    return false;
   Ptr.endLifetime();
   return true;
 }
diff --git a/clang/test/AST/ByteCode/lifetimes.cpp b/clang/test/AST/ByteCode/lifetimes.cpp
index 17f8d4e24bd85..658f696cad2e8 100644
--- a/clang/test/AST/ByteCode/lifetimes.cpp
+++ b/clang/test/AST/ByteCode/lifetimes.cpp
@@ -81,4 +81,10 @@ namespace PseudoDtor {
     }
     return true;
   }
+
+  int k;
+  struct T {
+    int n : (k.~I(), 1); // both-error {{constant expression}} \
+                         // both-note {{visible outside that expression}}
+  };
 }