[clang] [clang][bytecode] Fix an assertion failure in visitDtorCall() (PR #202507)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/202507

In `emitDestructionPop()`, we assert that the Descriptor has a non-trivial dtor. Check this first here so we don't do all this work for nothing.

>From 548dbe349630b4f2722c07931de8260c3331f029 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 9 Jun 2026 06:54:47 +0200
Subject: [PATCH] [clang][bytecode] Fix an assertion failure in visitDtorCall()

In `emitDestructionPop()`, we assert that the Descriptor has a
non-trivial dtor. Check this first here so we don't do all this work for
nothing.
---
 clang/lib/AST/ByteCode/Compiler.cpp |  5 +++++
 clang/test/AST/ByteCode/unions.cpp  | 12 ++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 76688e30a0acd..b89849b6983d8 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -5418,6 +5418,11 @@ bool Compiler<Emitter>::visitDtorCall(const VarDecl *VD, const APValue &Value) {
   if (!D)
     return false;
 
+  // FIXME: Would be nice if we didn't allocate the descriptor at all in this
+  // case.
+  if (D->hasTrivialDtor())
+    return true;
+
   Scope::Local Local = this->createLocal(D);
   Locals.insert({VD, Local});
   VarScope->addForScopeKind(Local, ScopeKind::Block);
diff --git a/clang/test/AST/ByteCode/unions.cpp b/clang/test/AST/ByteCode/unions.cpp
index 5f3676785fde6..ed435cb094a57 100644
--- a/clang/test/AST/ByteCode/unions.cpp
+++ b/clang/test/AST/ByteCode/unions.cpp
@@ -1084,3 +1084,15 @@ namespace Revive {
                             // both-note {{in call to}}
 }
 #endif
+
+namespace TrivialDtorInEvaluateDtor{
+  template <class T> void foo() {
+    union {
+      T t;
+    };
+  }
+  struct S {
+    ~S();
+  };
+  template void foo<S>();
+}