[Sema] Prevent binding incompatible addr space ref to temporaries

References to arbitrary address spaces can't always be bound to
temporaries. This change extends the reference binding logic to
check that the address space of a temporary can be implicitly
converted to the address space in a reference when temporary
materialization is performed.

Differential Revision: https://reviews.llvm.org/D61318

llvm-svn: 362604

1 files changed, 18 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 45456aff364..25aff40f26f 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -3344,6 +3344,7 @@ bool InitializationSequence::isAmbiguous() const {
   case FK_NonConstLValueReferenceBindingToVectorElement:
   case FK_NonConstLValueReferenceBindingToUnrelated:
   case FK_RValueReferenceBindingToLValue:
+  case FK_ReferenceAddrspaceMismatchTemporary:
   case FK_ReferenceInitDropsQualifiers:
   case FK_ReferenceInitFailed:
   case FK_ConversionFailed:
@@ -4837,9 +4838,16 @@ static void TryReferenceInitializationCore(Sema &S,
 
   Sequence.AddReferenceBindingStep(cv1T1IgnoreAS, /*bindingTemporary=*/true);
 
-  if (T1Quals.hasAddressSpace())
+  if (T1Quals.hasAddressSpace()) {
+    if (!Qualifiers::isAddressSpaceSupersetOf(T1Quals.getAddressSpace(),
+                                              LangAS::Default)) {
+      Sequence.SetFailed(
+          InitializationSequence::FK_ReferenceAddrspaceMismatchTemporary);
+      return;
+    }
     Sequence.AddQualificationConversionStep(cv1T1, isLValueRef ? VK_LValue
                                                                : VK_XValue);
+  }
 }
 
 /// Attempt character array initialization from a string literal
@@ -8516,6 +8524,11 @@ bool InitializationSequence::Diagnose(Sema &S,
       << Args[0]->getSourceRange();
     break;
 
+  case FK_ReferenceAddrspaceMismatchTemporary:
+    S.Diag(Kind.getLocation(), diag::err_reference_bind_temporary_addrspace)
+        << DestType << Args[0]->getSourceRange();
+    break;
+
   case FK_ReferenceInitDropsQualifiers: {
     QualType SourceType = OnlyArg->getType();
     QualType NonRefType = DestType.getNonReferenceType();
@@ -8851,6 +8864,10 @@ void InitializationSequence::dump(raw_ostream &OS) const {
       OS << "reference initialization drops qualifiers";
       break;
 
+    case FK_ReferenceAddrspaceMismatchTemporary:
+      OS << "reference with mismatching address space bound to temporary";
+      break;
+
     case FK_ReferenceInitFailed:
       OS << "reference initialization failed";
       break;