[clang] [clang][bytecode] Discard NullToPointer cast SubExpr (PR #104782)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/104782

So we still properly abort if they fail.

>From 0485b480347f69565c9d494365bce65c4f9a7a50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Mon, 19 Aug 2024 16:13:04 +0200
Subject: [PATCH] [clang][bytecode] Discard NullToPointer cast SubExpr

So we still properly abort if they fail.
---
 clang/lib/AST/ByteCode/Compiler.cpp | 2 ++
 clang/test/AST/ByteCode/codegen.cpp | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 53144a50ccf4a9..c839364d4c8d25 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -327,6 +327,8 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *CE) {
 
   case CK_NullToPointer:
   case CK_NullToMemberPointer: {
+    if (!this->discard(SubExpr))
+      return false;
     if (DiscardResult)
       return true;
 
diff --git a/clang/test/AST/ByteCode/codegen.cpp b/clang/test/AST/ByteCode/codegen.cpp
index 920a5ad7ba3e8f..9fac28a52d3150 100644
--- a/clang/test/AST/ByteCode/codegen.cpp
+++ b/clang/test/AST/ByteCode/codegen.cpp
@@ -64,3 +64,12 @@ namespace Bitfield {
   // CHECK: store ptr @_ZGRN8Bitfield1rE_, ptr @_ZN8Bitfield1rE, align 8
   int &&r = S().a;
 }
+
+namespace Null {
+  decltype(nullptr) null();
+  // CHECK: call {{.*}} @_ZN4Null4nullEv(
+  int *p = null();
+  struct S {};
+  // CHECK: call {{.*}} @_ZN4Null4nullEv(
+  int S::*q = null();
+}