[PR 81702] Remove devirtualization assert

[Martin Jambor <mjambor at suse dot cz>]

Hi,

in PR 81702, both me and Honza came to the conclusion that the assert
that is being hit can be removed if it is indeed OK that a particular
variable is constructed without a DECL_INITIAL.  Yesterday Nathan
confirmed that in this case it is fine.  So the patch below removes
the assert.

Bootstrapped and tested on x86_64-linux, I will commit it to teunk as
pre-approved in Bugzilla in a few moments.  I will commit it tomorrow
to the gcc-7-branch after testing it there too.

Thanks,

Martin


2017-10-31  Martin Jambor  <mjambor@suse.cz>

	PR c++/81702
	* gimple-fold.c (gimple_get_virt_method_for_vtable): Remove assert.

testsuite/
	* g++.dg/tree-ssa/pr81702.C: New test.
---
 gcc/gimple-fold.c                       |   1 -
 gcc/testsuite/g++.dg/tree-ssa/pr81702.C | 110 ++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/tree-ssa/pr81702.C

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index cb33c1e09fe..85fd3971946 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -6586,7 +6586,6 @@ gimple_get_virt_method_for_vtable (HOST_WIDE_INT token,
   gcc_assert (init);
   if (init == error_mark_node)
     {
-      gcc_assert (in_lto_p);
       /* Pass down that we lost track of the target.  */
       if (can_refer)
 	*can_refer = false;
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr81702.C b/gcc/testsuite/g++.dg/tree-ssa/pr81702.C
new file mode 100644
index 00000000000..85acd857e67
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr81702.C
@@ -0,0 +1,110 @@
+// { dg-do compile }
+// { dg-options "-O2" }
+
+namespace std {
+  struct type_info
+  {
+    virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
+       unsigned __outer) const;
+  };
+}
+
+template< typename VALUE_T, typename TYPE >
+struct List_policy
+{
+  typedef VALUE_T *Value_type;
+  typedef TYPE **Type;
+  typedef TYPE *Head_type;
+  typedef TYPE Item_type;
+};
+
+template< typename POLICY >
+class List
+{
+public:
+  typedef typename POLICY::Value_type Value_type;
+  class Iterator
+  {
+    typedef typename POLICY::Type Internal_type;
+  public:
+    typedef typename POLICY::Value_type value_type;
+    typedef typename POLICY::Value_type Value_type;
+    Value_type operator -> () const { return static_cast<Value_type>(*_c); }
+    Internal_type _c;
+  };
+  Iterator begin() { return Iterator(); }
+  Iterator end() { return Iterator(); }
+  typename POLICY::Head_type _f;
+};
+
+template<typename ELEM_TYPE> class H_list_item_t { };
+
+template< typename T, typename POLICY >
+class H_list : public List<POLICY>
+{
+public:
+  typedef typename POLICY::Item_type Item;
+  typedef List<POLICY> Base;
+  typedef typename Base::Iterator Iterator;
+  Iterator insert(T *e, Iterator const &pred)
+  {
+    Item **x = &this->_f;
+    *x = static_cast<Item*>(e);
+    return Iterator();
+  }
+};
+
+template< typename T >
+struct H_list_t : H_list<T, List_policy< T, H_list_item_t<T> > >
+{
+  H_list_t(bool b) : H_list<T, List_policy< T, H_list_item_t<T> > >(b) {}
+};
+
+template< typename BASE, typename MATCH_RESULT >
+struct Type_matcher : H_list_item_t<BASE>
+{
+  explicit Type_matcher(std::type_info const *type);
+  typedef MATCH_RESULT Match_result;
+
+private:
+  std::type_info *_type;
+  typedef H_list_t<BASE> List;
+  typedef typename List::Iterator Iterator;
+  static List _for_type;
+};
+
+template< typename BASE, typename MR >
+Type_matcher<BASE, MR>::Type_matcher(std::type_info const *t)
+{
+  Iterator c = _for_type.begin();
+  t->__do_catch(c->_type, 0, 0);
+  _for_type.insert(static_cast<BASE*>(this), _for_type.begin());
+}
+
+template< typename VI, typename HW >
+class Fa : public Type_matcher<Fa<VI, HW>, VI*>
+{
+public:
+  typedef Fa<VI, HW> Self;
+  virtual VI *do_match(HW *f) = 0;
+  explicit Fa(std::type_info const *type) : Type_matcher<Self, VI*>(type) {}
+};
+
+class Res {};
+typedef Fa<Res, Res> R_fac;
+
+template< typename VI, typename HW_BASE, typename HW, typename BASE >
+class Fa_t : public BASE
+{
+public:
+  Fa_t() : BASE(&typeid(HW)) {}
+  VI *do_match(HW_BASE *) { return 0; }
+};
+
+template< typename VI, typename HW >
+class Resource_factory_t : public Fa_t<VI, Res, HW, R_fac > {};
+
+class Foo {};
+class Foo2;
+class Foo3 : public Res {};
+Resource_factory_t<Foo3, Foo> _x;
-- 
2.14.2