PR c++/83720 - ICE with lambda and LTO.

	* decl2.c (determine_visibility): Clear template_decl for
	function-scope decls.  Propagate anonymous linkage from containing
	function.

From-SVN: r256964

gcc/cp/ChangeLog

+2018-01-22  Jason Merrill  <jason@redhat.com>
+
+	PR c++/83720 - ICE with lambda and LTO.
+	* decl2.c (determine_visibility): Clear template_decl for
+	function-scope decls.  Propagate anonymous linkage from containing
+	function.
+
 2018-01-22  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/81933

gcc/cp/decl2.c

@@ -2388,7 +2388,9 @@ determine_visibility (tree decl)
 	     containing function by default, except that
 	     -fvisibility-inlines-hidden doesn't affect them.  */
 	  tree fn = DECL_CONTEXT (decl);
-	  if (DECL_VISIBILITY_SPECIFIED (fn))
+	  if (! TREE_PUBLIC (fn))
+	    constrain_visibility (decl, VISIBILITY_ANON, false);
+	  else if (DECL_VISIBILITY_SPECIFIED (fn))
 	    {
 	      DECL_VISIBILITY (decl) = DECL_VISIBILITY (fn);
 	      DECL_VISIBILITY_SPECIFIED (decl) = 
@@ -2414,10 +2416,9 @@ determine_visibility (tree decl)
 
 	  /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
 	     but have no TEMPLATE_INFO.  Their containing template
-	     function does, and the local class could be constrained
-	     by that.  */
-	  if (template_decl)
-	    template_decl = fn;
+	     function determines their visibility, so we neither
+	     need nor want the template_decl handling.  */
+	  template_decl = NULL_TREE;
 	}
       else if (VAR_P (decl) && DECL_TINFO_P (decl)
 	       && flag_visibility_ms_compat)

gcc/testsuite/g++.dg/lto/pr83720_0.C

+// PR c++/83720
+// { dg-lto-do assemble }
+
+#pragma GCC diagnostic ignored "-Wreturn-type"
+
+namespace b {
+class h {
+public:
+  template <typename ae, typename af> h(ae af::*...) {
+    [] {};
+  }
+};
+class ai {};
+template <typename> class c {
+public:
+  template <typename ag> void aj(const char *, ag f) { h(f, int()); }
+};
+}
+template <typename> class al;
+template <typename e> class i {
+protected:
+  static e g(const int) {  }
+};
+template <typename, typename> class j;
+template <typename an, typename e, typename... ao>
+class j<an(ao...), e> : i<e> {
+  typedef i<e> ap;
+
+public:
+  static an aq(const int &ar, ao... as) { ap::g(ar)(as...); }
+};
+template <typename an, typename... ao> class al<an(ao...)> {
+  template <typename, typename a> using ax = a;
+
+public:
+  template <typename e, typename = ax<int, void>, typename = ax<int, void>>
+  al(e);
+  using ay = an (*)(const int &, ao...);
+  ay az;
+};
+template <typename an, typename... ao>
+template <typename e, typename, typename>
+al<an(ao...)>::al(e) {
+  az = j<an(ao...), e>::aq;
+}
+class k {
+public:
+  k(al<void(b::ai)>);
+} d([](b::ai) {
+  struct be {
+    virtual void f();
+  };
+  struct bf;
+  b::c<bf>().aj("", &be::f);
+});