@@ -941,8 +941,17 @@ process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
goto bad;
}
- if (constexpr_p && !DECL_DECLARED_CONSTEXPR_P (fn))
- *constexpr_p = false;
+ if (constexpr_p)
+ {
+ /* If this is a specialization of a constexpr template, we need to
+ force the instantiation now so that we know whether or not it's
+ really constexpr. */
+ if (DECL_DECLARED_CONSTEXPR_P (fn) && DECL_TEMPLATE_INSTANTIATION (fn)
+ && !DECL_TEMPLATE_INSTANTIATED (fn))
+ instantiate_decl (fn, /*defer_ok*/false, /*expl_class*/false);
+ if (!DECL_DECLARED_CONSTEXPR_P (fn))
+ *constexpr_p = false;
+ }
return;
@@ -256,6 +256,7 @@ maybe_clone_body (tree fn)
/* Update CLONE's source position information to match FN's. */
DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn);
DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn);
+ DECL_DECLARED_CONSTEXPR_P (clone) = DECL_DECLARED_CONSTEXPR_P (fn);
DECL_COMDAT (clone) = DECL_COMDAT (fn);
DECL_WEAK (clone) = DECL_WEAK (fn);
new file mode 100644
@@ -0,0 +1,14 @@
+// PR c++/46472
+// { dg-options -std=c++0x }
+
+template<class T> struct A {
+ T t;
+ constexpr A(){}
+};
+
+struct B
+{
+ A<int> a;
+};
+
+B b;