[clang] [clang][bytecode] Fix discarded addrof operators... (PR #180534)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

... of member pointers.

---
Full diff: https://github.com/llvm/llvm-project/pull/180534.diff


2 Files Affected:

- (modified) clang/lib/AST/ByteCode/Compiler.cpp (+2) 
- (modified) clang/test/AST/ByteCode/memberpointers.cpp (+9) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index a0138c402e143..9f271f3c314dd 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -6859,6 +6859,8 @@ bool Compiler<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
     if (E->getType()->isMemberPointerType()) {
       // C++11 [expr.unary.op]p3 has very strict rules on how the address of a
       // member can be formed.
+      if (DiscardResult)
+        return true;
       return this->emitGetMemberPtr(cast<DeclRefExpr>(SubExpr)->getDecl(), E);
     }
     // We should already have a pointer when we get here.
diff --git a/clang/test/AST/ByteCode/memberpointers.cpp b/clang/test/AST/ByteCode/memberpointers.cpp
index 5d622187e97f2..88666c3e38f44 100644
--- a/clang/test/AST/ByteCode/memberpointers.cpp
+++ b/clang/test/AST/ByteCode/memberpointers.cpp
@@ -267,3 +267,12 @@ namespace CastMemberPtrPtrFailed{
   static_assert(S().g(), ""); // both-error {{constant expression}} \
                               // both-note {{in call to 'S().g()'}}
 }
+
+namespace DiscardedAddrOfOperator {
+  class Foo {
+  public:
+    void bar();
+  };
+
+  void baz() { &Foo::bar, Foo(); }
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/180534