[clang] [clang][bytecode] Diagnose delete with non-virtual dtor (PR #114373)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

... in the base class.

---
Full diff: https://github.com/llvm/llvm-project/pull/114373.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/Interp.cpp (+18) 
- (modified) clang/test/AST/ByteCode/new-delete.cpp (+10) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 513d4512b45cff..3094d7986f9986 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -1002,6 +1002,13 @@ static bool RunDestructors(InterpState &S, CodePtr OpPC, const Block *B) {
   return runRecordDestructor(S, OpPC, Pointer(const_cast<Block *>(B)), Desc);
 }
 
+static bool hasVirtualDestructor(QualType T) {
+  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
+    if (const CXXDestructorDecl *DD = RD->getDestructor())
+      return DD->isVirtual();
+  return false;
+}
+
 bool Free(InterpState &S, CodePtr OpPC, bool DeleteIsArrayForm,
           bool IsGlobalDelete) {
   if (!CheckDynamicMemoryAllocation(S, OpPC))
@@ -1019,9 +1026,20 @@ bool Free(InterpState &S, CodePtr OpPC, bool DeleteIsArrayForm,
       return true;
 
     // Remove base casts.
+    QualType InitialType = Ptr.getType();
     while (Ptr.isBaseClass())
       Ptr = Ptr.getBase();
 
+    // For the non-array case, the types must match if the static type
+    // does not have a virtual destructor.
+    if (!DeleteIsArrayForm && Ptr.getType() != InitialType &&
+        !hasVirtualDestructor(InitialType)) {
+      S.FFDiag(S.Current->getSource(OpPC),
+               diag::note_constexpr_delete_base_nonvirt_dtor)
+          << InitialType << Ptr.getType();
+      return false;
+    }
+
     if (!Ptr.isRoot() || Ptr.isOnePastEnd() || Ptr.isArrayElement()) {
       const SourceInfo &Loc = S.Current->getSource(OpPC);
       S.FFDiag(Loc, diag::note_constexpr_delete_subobject)
diff --git a/clang/test/AST/ByteCode/new-delete.cpp b/clang/test/AST/ByteCode/new-delete.cpp
index 94fe2d4497df6a..31c8da93a3a643 100644
--- a/clang/test/AST/ByteCode/new-delete.cpp
+++ b/clang/test/AST/ByteCode/new-delete.cpp
@@ -569,6 +569,16 @@ namespace CastedDelete {
     return a;
   }
   static_assert(vdtor_1() == 1);
+
+  constexpr int foo() { // both-error {{never produces a constant expression}}
+      struct S {};
+      struct T : S {};
+      S *p = new T();
+      delete p; // both-note 2{{delete of object with dynamic type 'T' through pointer to base class type 'S' with non-virtual destructor}}
+      return 1;
+  }
+  static_assert(foo() == 1); // both-error {{not an integral constant expression}} \
+                             // both-note {{in call to}}
 }
 
 constexpr void use_after_free_2() { // both-error {{never produces a constant expression}}

``````````

</details>


https://github.com/llvm/llvm-project/pull/114373