[Sema debugger support] Require non-void types to be complete in unknown-anytype casts.

When performing a cast from an __unknown_anytype function call to a
non-void type, we need to make sure that type is complete. Fixes
rdar://problem/23959960.

llvm-svn: 259681

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index b7d494fa5cb..dc638798d10 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -14478,6 +14478,12 @@ ExprResult RebuildUnknownAnyExpr::resolveDecl(Expr *E, ValueDecl *VD) {
 ExprResult Sema::checkUnknownAnyCast(SourceRange TypeRange, QualType CastType,
                                      Expr *CastExpr, CastKind &CastKind,
                                      ExprValueKind &VK, CXXCastPath &Path) {
+  // The type we're casting to must be either void or complete.
+  if (!CastType->isVoidType() &&
+      RequireCompleteType(TypeRange.getBegin(), CastType,
+                          diag::err_typecheck_cast_to_incomplete))
+    return ExprError();
+
   // Rewrite the casted expression from scratch.
   ExprResult result = RebuildUnknownAnyExpr(*this, CastType).Visit(CastExpr);
   if (!result.isUsable()) return ExprError();