From fb46105ceed81ebea8088228969352ac6c52e891 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder@redhat.com>
Date: Fri, 21 Nov 2025 15:20:40 +0100
Subject: [PATCH] [clang][bytecode] Don't call getThis() on the bottom function
 frame

We can't access the calling frame in that case.

Fixes https://github.com/llvm/llvm-project/issues/169032
---
 clang/lib/AST/ByteCode/Interp.cpp      |  3 ++-
 clang/lib/AST/ByteCode/InterpFrame.h   |  2 ++
 clang/test/AST/ByteCode/new-delete.cpp | 12 ++++++++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 280911c324bb1..4222fd97a84fa 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1407,7 +1407,8 @@ bool CheckLiteralType(InterpState &S, CodePtr OpPC, const Type *T) {
   //   http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1677
   // Therefore, we use the C++1y behavior.
 
-  if (S.Current->getFunction() && S.Current->getFunction()->isConstructor() &&
+  if (!S.Current->isBottomFrame() &&
+      S.Current->getFunction()->isConstructor() &&
       S.Current->getThis().getDeclDesc()->asDecl() == S.EvaluatingDecl) {
     return true;
   }
diff --git a/clang/lib/AST/ByteCode/InterpFrame.h b/clang/lib/AST/ByteCode/InterpFrame.h
index fa9de2e1e7c6d..febef1097ea8a 100644
--- a/clang/lib/AST/ByteCode/InterpFrame.h
+++ b/clang/lib/AST/ByteCode/InterpFrame.h
@@ -109,6 +109,7 @@ class InterpFrame final : public Frame {
   /// Returns the 'this' pointer.
   const Pointer &getThis() const {
     assert(hasThisPointer());
+    assert(!isBottomFrame());
     return stackRef<Pointer>(ThisPointerOffset);
   }
 
@@ -116,6 +117,7 @@ class InterpFrame final : public Frame {
   const Pointer &getRVOPtr() const {
     assert(Func);
     assert(Func->hasRVO());
+    assert(!isBottomFrame());
     return stackRef<Pointer>(0);
   }
 
diff --git a/clang/test/AST/ByteCode/new-delete.cpp b/clang/test/AST/ByteCode/new-delete.cpp
index 9e0f33e212c18..43e1f6bfcc9a6 100644
--- a/clang/test/AST/ByteCode/new-delete.cpp
+++ b/clang/test/AST/ByteCode/new-delete.cpp
@@ -1114,6 +1114,18 @@ namespace ZeroSizeArray {
   static_assert(foo() == 0);
 }
 
+namespace NonLiteralType {
+  /// This used to crash.
+  constexpr void foo() {
+    struct O {};
+
+    struct S {
+      O *s;
+      constexpr S() : s{std::allocator<O>{}.allocate(1)} {}
+    };
+  }
+}
+
 #else
 /// Make sure we reject this prior to C++20
 constexpr int a() { // both-error {{never produces a constant expression}}