[llvm-branch-commits] [clang] fa656d9 - [clang][bytecode] Diagnose regular CK_LValueBitCast cast nodes (#175721)

[Cullen Rhodes via llvm-branch-commits]

Author: Timm Baeder
Date: 2026-01-13T10:18:55Z
New Revision: fa656d9cd4b04b3ced5fb628256bb565fa4895fd

URL: https://github.com/llvm/llvm-project/commit/fa656d9cd4b04b3ced5fb628256bb565fa4895fd
DIFF: https://github.com/llvm/llvm-project/commit/fa656d9cd4b04b3ced5fb628256bb565fa4895fd.diff

LOG: [clang][bytecode] Diagnose regular CK_LValueBitCast cast nodes (#175721)

We already do this similarly for CXXReinterpretCastExprs, except in that
case we try harder to make things work.

Added: 
    

Modified: 
    clang/lib/AST/ByteCode/Compiler.cpp
    clang/test/AST/ByteCode/cxx11.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index a67648aa2aff9..0a0a5dd5c47c8 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -779,6 +779,9 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *CE) {
     // a diagnostic if appropriate.
     return this->delegate(SubExpr);
 
+  case CK_LValueBitCast:
+    return this->emitInvalidCast(CastKind::ReinterpretLike, /*Fatal=*/true, CE);
+
   default:
     return this->emitInvalid(CE);
   }

diff  --git a/clang/test/AST/ByteCode/cxx11.cpp b/clang/test/AST/ByteCode/cxx11.cpp
index 9a61321f67a40..e1fb5948b7708 100644
--- a/clang/test/AST/ByteCode/cxx11.cpp
+++ b/clang/test/AST/ByteCode/cxx11.cpp
@@ -33,6 +33,10 @@ constexpr int b = b; // both-error {{must be initialized by a constant expressio
                                                       // both-note {{declared here}}
 
 
+  void func();
+  constexpr int (&fp4)() = (int(&)())func; // both-error {{constant expression}} \
+                                           // both-note {{reinterpret_cast}}
+
 struct S {
   int m;
 };