Don't allow reinterpret_cast to reference of vector element and property expression. Thanks goes to Eli Friedman!

llvm-svn: 130036

3 files changed, 18 insertions, 6 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 6e130b17972..910536ab7a6 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2879,8 +2879,8 @@ def err_bad_cxx_cast_member_pointer_size : Error<
   "cannot %select{||reinterpret_cast||C-style cast|}0 from member pointer "
   "type %1 to member pointer type %2 of different size">;
 def err_bad_static_cast_incomplete : Error<"%0 is an incomplete type">;
-def err_bad_reinterpret_cast_bitfield : Error<
-  "reinterpret_cast of a bit-field to %2 needs its address which is not allowed">;
+def err_bad_reinterpret_cast_reference : Error<
+  "reinterpret_cast of a %0 to %1 needs its address which is not allowed">;
 
 // These messages don't adhere to the pattern.
 // FIXME: Display the path somehow better.
diff --git a/clang/lib/Sema/SemaCXXCast.cpp b/clang/lib/Sema/SemaCXXCast.cpp
index 29475539d71..743fdd25665 100644
--- a/clang/lib/Sema/SemaCXXCast.cpp
+++ b/clang/lib/Sema/SemaCXXCast.cpp
@@ -1327,9 +1327,18 @@ static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
     //   same effect as the conversion *reinterpret_cast<T*>(&x) with the
     //   built-in & and * operators.
 
-    // Cannot get address of a bitfield.
-    if (SrcExpr.get()->getObjectKind() == OK_BitField) {
-      msg = diag::err_bad_reinterpret_cast_bitfield;
+    const char *inappropriate = 0;
+    switch (SrcExpr.get()->getObjectKind()) {
+    default: break;
+    case OK_BitField:        inappropriate = "bit-field";           break;
+    case OK_VectorComponent: inappropriate = "vector element";      break;
+    case OK_ObjCProperty:    inappropriate = "property expression"; break;
+    }
+    if (inappropriate) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
+          << inappropriate << DestType
+          << OpRange << SrcExpr.get()->getSourceRange();
+      msg = 0; SrcExpr = ExprError();
       return TC_NotApplicable;
     }
 
diff --git a/clang/test/SemaCXX/reinterpret-cast.cpp b/clang/test/SemaCXX/reinterpret-cast.cpp
index 2ec45b37cde..f5262496c4b 100644
--- a/clang/test/SemaCXX/reinterpret-cast.cpp
+++ b/clang/test/SemaCXX/reinterpret-cast.cpp
@@ -111,5 +111,8 @@ void const_arrays() {
 
 namespace PR9564 {
   struct a { int a : 10; }; a x;
-  int *y = &reinterpret_cast<int&>(x.a); // expected-error {{reinterpret_cast of a bit-field to 'int &' needs its address which is not allowed}}
+  int *y = &reinterpret_cast<int&>(x.a); // expected-error {{not allowed}}
+
+  __attribute((ext_vector_type(4))) typedef float v4;
+  float& w(v4 &a) { return reinterpret_cast<float&>(a[1]); } // expected-error {{not allowed}}
 }