Require the type of a by-copy capture to be complete before creating its field.

The problem here is more serious than the fix implies. Adding a field
to a class updates the triviality bits for the class (among other
things). Failing to require a complete type before adding the field
meant that these updates don't happen in the well-formed case where
the capture is an uninstantiated class template specialization,
leading the lambda itself to be treated as having a trivial copy
constructor when it shouldn't. Fixes <rdar://problem/15560464>.

llvm-svn: 197623

1 files changed, 9 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index fcd972436da..a1de4046e0f 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -11617,6 +11617,15 @@ static ExprResult addAsFieldToClosureType(Sema &S,
                                   bool RefersToEnclosingLocal) {
   CXXRecordDecl *Lambda = LSI->Lambda;
 
+  // Make sure that by-copy captures are of a complete type.
+  if (!DeclRefType->isDependentType() &&
+      !DeclRefType->isReferenceType() &&
+      S.RequireCompleteType(Loc, DeclRefType,
+                            diag::err_capture_of_incomplete_type,
+                            Var->getDeclName())) {
+    return ExprError();
+  }
+
   // Build the non-static data member.
   FieldDecl *Field
     = FieldDecl::Create(S.Context, Lambda, Loc, Loc, 0, FieldType,