1 files changed, 21 insertions, 4 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index d8c0896147..8bb306e66d 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -7724,9 +7724,9 @@ checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) {
   }
 
   if (!lhq.compatiblyIncludes(rhq)) {
-    // Treat address-space mismatches as fatal.  TODO: address subspaces
+    // Treat address-space mismatches as fatal.
     if (!lhq.isAddressSpaceSupersetOf(rhq))
-      ConvTy = Sema::IncompatiblePointerDiscardsQualifiers;
+      return Sema::IncompatiblePointerDiscardsQualifiers;
 
     // It's okay to add or remove GC or lifetime qualifiers when converting to
     // and from void*.
@@ -7799,8 +7799,22 @@ checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) {
     // level of indirection, this must be the issue.
     if (isa<PointerType>(lhptee) && isa<PointerType>(rhptee)) {
       do {
-        lhptee = cast<PointerType>(lhptee)->getPointeeType().getTypePtr();
-        rhptee = cast<PointerType>(rhptee)->getPointeeType().getTypePtr();
+        std::tie(lhptee, lhq) =
+          cast<PointerType>(lhptee)->getPointeeType().split().asPair();
+        std::tie(rhptee, rhq) =
+          cast<PointerType>(rhptee)->getPointeeType().split().asPair();
+
+        // Inconsistent address spaces at this point is invalid, even if the
+        // address spaces would be compatible.
+        // FIXME: This doesn't catch address space mismatches for pointers of
+        // different nesting levels, like:
+        //   __local int *** a;
+        //   int ** b = a;
+        // It's not clear how to actually determine when such pointers are
+        // invalidly incompatible.
+        if (lhq.getAddressSpace() != rhq.getAddressSpace())
+          return Sema::IncompatibleNestedPointerAddressSpaceMismatch;
+
       } while (isa<PointerType>(lhptee) && isa<PointerType>(rhptee));
 
       if (lhptee == rhptee)
@@ -14213,6 +14227,9 @@ bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy,
   case IncompatibleNestedPointerQualifiers:
     DiagKind = diag::ext_nested_pointer_qualifier_mismatch;
     break;
+  case IncompatibleNestedPointerAddressSpaceMismatch:
+    DiagKind = diag::err_typecheck_incompatible_nested_address_space;
+    break;
   case IntToBlockPointer:
     DiagKind = diag::err_int_to_block_pointer;
     break;