[clang] [clang][bytecode] Fix AccessKinds in placement new CheckStore() call (PR #141123)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/141123

CheckStore is for assignments, but we're constructing something here, so pass AK_Construct instead. We already diagnosed the test case, but as an assignment.

>From dc798c13b85c7730a99b987c334e550f11d8a51c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Thu, 22 May 2025 21:01:55 +0200
Subject: [PATCH] [clang][bytecode] Fix AccessKinds in placement new
 CheckStore() call

CheckStore is for assignments, but we're constructing something here, so
pass AK_Construct instead. We already diagnosed the test case, but as an
assignment.
---
 clang/lib/AST/ByteCode/Interp.cpp         | 20 +++++++++++++++++++-
 clang/test/AST/ByteCode/placement-new.cpp | 15 +++++++++++++--
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index b3ac84ce9278f..345c518b59fd3 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1702,7 +1702,25 @@ bool CheckNewTypeMismatch(InterpState &S, CodePtr OpPC, const Expr *E,
                           std::optional<uint64_t> ArraySize) {
   const Pointer &Ptr = S.Stk.peek<Pointer>();
 
-  if (!CheckStore(S, OpPC, Ptr))
+  // Similar to CheckStore(), but with the additional CheckTemporary() call and
+  // the AccessKinds are different.
+  if (!CheckTemporary(S, OpPC, Ptr, AK_Construct))
+    return false;
+  if (!CheckLive(S, OpPC, Ptr, AK_Construct))
+    return false;
+  if (!CheckDummy(S, OpPC, Ptr, AK_Construct))
+    return false;
+  if (!CheckLifetime(S, OpPC, Ptr, AK_Construct))
+    return false;
+  if (!CheckExtern(S, OpPC, Ptr))
+    return false;
+  if (!CheckRange(S, OpPC, Ptr, AK_Construct))
+    return false;
+  if (!CheckGlobal(S, OpPC, Ptr))
+    return false;
+  if (!CheckConst(S, OpPC, Ptr))
+    return false;
+  if (!S.inConstantContext() && isConstexprUnknown(Ptr))
     return false;
 
   if (!InvalidNewDeleteExpr(S, OpPC, E))
diff --git a/clang/test/AST/ByteCode/placement-new.cpp b/clang/test/AST/ByteCode/placement-new.cpp
index 14b893c7e587b..4c4e23f032580 100644
--- a/clang/test/AST/ByteCode/placement-new.cpp
+++ b/clang/test/AST/ByteCode/placement-new.cpp
@@ -15,8 +15,8 @@ namespace std {
   constexpr void construct_at(void *p, Args &&...args) {
     new (p) T((Args&&)args...); // both-note {{in call to}} \
                                 // both-note {{placement new would change type of storage from 'int' to 'float'}} \
-                                // both-note {{construction of subobject of member 'x' of union with active member 'a' is not allowed in a constant expression}}
-
+                                // both-note {{construction of subobject of member 'x' of union with active member 'a' is not allowed in a constant expression}} \
+                                // both-note {{construction of heap allocated object that has been deleted}}
   }
 }
 
@@ -391,3 +391,14 @@ namespace MemMove {
 
   static_assert(foo() == 123);
 }
+
+namespace PlacementNewAfterDelete {
+  constexpr bool construct_after_lifetime() {
+    int *p = new int;
+    delete p;
+    std::construct_at<int>(p); // both-note {{in call}}
+    return true;
+  }
+  static_assert(construct_after_lifetime()); // both-error {{}} \
+                                             // both-note {{in call}}
+}