[clang] [clang][bytecode] Narrow pointer in UO_Deref unary operators (PR #113089)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/113089

>From 6942291d0f529baa323cfd35e2f5d9b4f818c0f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Sun, 20 Oct 2024 13:57:49 +0200
Subject: [PATCH] [clang][bytecode] Narrow pointer in UO_Deref unary operators

Otherwise we treat this like an array element even though we should
treat it as a single object.
---
 clang/lib/AST/ByteCode/Compiler.cpp | 12 ++++++++++--
 clang/lib/AST/ByteCode/Pointer.cpp  |  2 +-
 clang/test/AST/ByteCode/cxx98.cpp   |  5 +++++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 672fa7fc25d6d0..3f068aa8c189a9 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -5738,9 +5738,17 @@ bool Compiler<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     // We should already have a pointer when we get here.
     return this->delegate(SubExpr);
   case UO_Deref: // *x
-    if (DiscardResult)
+    if (DiscardResult) {
+      // assert(false);
       return this->discard(SubExpr);
-    return this->visit(SubExpr);
+    }
+
+    if (!this->visit(SubExpr))
+      return false;
+    if (classifyPrim(SubExpr) == PT_Ptr)
+      return this->emitNarrowPtr(E);
+    return true;
+
   case UO_Not: // ~x
     if (!T)
       return this->emitError(E);
diff --git a/clang/lib/AST/ByteCode/Pointer.cpp b/clang/lib/AST/ByteCode/Pointer.cpp
index 75b00dcb2ab242..c9de039c195d94 100644
--- a/clang/lib/AST/ByteCode/Pointer.cpp
+++ b/clang/lib/AST/ByteCode/Pointer.cpp
@@ -635,7 +635,7 @@ std::optional<APValue> Pointer::toRValue(const Context &Ctx,
 
   // Return the composite type.
   APValue Result;
-  if (!Composite(getType(), *this, Result))
+  if (!Composite(ResultType, *this, Result))
     return std::nullopt;
   return Result;
 }
diff --git a/clang/test/AST/ByteCode/cxx98.cpp b/clang/test/AST/ByteCode/cxx98.cpp
index 471a58f8e05518..20f98d33c31c4f 100644
--- a/clang/test/AST/ByteCode/cxx98.cpp
+++ b/clang/test/AST/ByteCode/cxx98.cpp
@@ -54,3 +54,8 @@ _Static_assert(a == 0, ""); // both-error {{static assertion expression is not a
 struct SelfReference { SelfReference &r; };
 extern SelfReference self_reference_1;
 SelfReference self_reference_2 = {self_reference_1};
+
+struct PR65784s{
+  int *ptr;
+} const PR65784[] = {(int *)""};
+PR65784s PR65784f() { return *PR65784; }