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

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

Otherwise we treat this like an array element even though we should treat it as a single object.

---
Full diff: https://github.com/llvm/llvm-project/pull/113089.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/Compiler.cpp (+10-2) 
- (modified) clang/test/AST/ByteCode/cxx98.cpp (+5) 


``````````diff
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/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; }

``````````

</details>


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