PR c++/88049 - ICE with undefined destructor and anon namespace.

A type in an anonymous namespace can never be merged with one from
another translation unit, so a member of such a type is always its own
prevailing decl.

	* lto-symtab.c (lto_symtab_prevailing_virtual_decl): Return early
	for a type in an anonymous namespace.

From-SVN: r269283

gcc/lto/ChangeLog

+2019-02-28  Jason Merrill  <jason@redhat.com>
+
+	PR c++/88049 - ICE with undefined destructor and anon namespace.
+	* lto-symtab.c (lto_symtab_prevailing_virtual_decl): Return early
+	for a type in an anonymous namespace.
+
 2019-01-09  Sandra Loosemore  <sandra@codesourcery.com>
 
 	PR other/16615

gcc/lto/lto-symtab.c

@@ -1085,8 +1085,12 @@ lto_symtab_prevailing_virtual_decl (tree decl)
 {
   if (DECL_ABSTRACT_P (decl))
     return decl;
-  gcc_checking_assert (!type_in_anonymous_namespace_p (DECL_CONTEXT (decl))
-		       && DECL_ASSEMBLER_NAME_SET_P (decl));
+
+  if (type_in_anonymous_namespace_p (DECL_CONTEXT (decl)))
+    /* There can't be any other declarations.  */
+    return decl;
+
+  gcc_checking_assert (DECL_ASSEMBLER_NAME_SET_P (decl));
 
   symtab_node *n = symtab_node::get_for_asmname
 		     (DECL_ASSEMBLER_NAME (decl));

gcc/testsuite/g++.dg/lto/pr88049_0.C

+// PR c++/88049
+// { dg-lto-do link }
+// { dg-lto-options {{ -flto -O2 -w }} }
+// { dg-extra-ld-options -r }
+
+template <typename> class a;
+class b {};
+template <typename e> a<e> d(char);
+template <typename> class a : public b {
+public:
+  virtual ~a();
+};
+namespace {
+  class f;
+  b c = d<f>(int());
+} // namespace