[clang] c2ae572 - [clang][bytecode] Allow reinterpret casts from/to the same pointer type (#136692)

[via cfe-commits]

Author: Timm Baeder
Date: 2025-04-22T16:50:42+02:00
New Revision: c2ae5723b5418fa0f5901f2c21c2c905fa48a498

URL: https://github.com/llvm/llvm-project/commit/c2ae5723b5418fa0f5901f2c21c2c905fa48a498
DIFF: https://github.com/llvm/llvm-project/commit/c2ae5723b5418fa0f5901f2c21c2c905fa48a498.diff

LOG: [clang][bytecode] Allow reinterpret casts from/to the same pointer type (#136692)

Added: 
    

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

Removed: 
    


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diff  --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp
index 3e53f2a2c8557..7cba0e8a4da19 100644
--- a/clang/lib/AST/ByteCode/Compiler.cpp
+++ b/clang/lib/AST/ByteCode/Compiler.cpp
@@ -2990,6 +2990,8 @@ bool Compiler<Emitter>::VisitCXXReinterpretCastExpr(
     if (PointeeToT && PointeeFromT) {
       if (isIntegralType(*PointeeFromT) && isIntegralType(*PointeeToT))
         Fatal = false;
+    } else {
+      Fatal = SubExpr->getType().getTypePtr() != E->getType().getTypePtr();
     }
 
     if (!this->emitInvalidCast(CastKind::Reinterpret, Fatal, E))

diff  --git a/clang/test/AST/ByteCode/cxx11.cpp b/clang/test/AST/ByteCode/cxx11.cpp
index 23582e9ab556a..4c69517304ea7 100644
--- a/clang/test/AST/ByteCode/cxx11.cpp
+++ b/clang/test/AST/ByteCode/cxx11.cpp
@@ -185,3 +185,11 @@ namespace InitLinkToRVO {
   constexpr A make() { return A {}; }
   static_assert(make().z == 4, "");
 }
+
+namespace DynamicCast {
+  struct S { int x, y; } s;
+  constexpr S* sptr = &s;
+  struct Str {
+    int b : reinterpret_cast<S*>(sptr) == reinterpret_cast<S*>(sptr);
+  };
+}