re PR c++/82159 (ICE: in assign_temp, at function.c:961)

	PR c++/82159
	* gimplify.c (gimplify_modify_expr): Don't optimize away zero sized
	lhs from calls if the lhs has addressable type.

	* g++.dg/opt/pr82159.C: New test.

From-SVN: r253230

gcc/ChangeLog

+2017-09-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/82159
+	* gimplify.c (gimplify_modify_expr): Don't optimize away zero sized
+	lhs from calls if the lhs has addressable type.
+
 2017-09-27  Richard Biener  <rguenther@suse.de>
 
 	* graphite.h (scop::max_alias_set): New member.

gcc/gimplify.c

@@ -5479,7 +5479,12 @@ gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
      side as statements and throw away the assignment.  Do this after
      gimplify_modify_expr_rhs so we handle TARGET_EXPRs of addressable
      types properly.  */
-  if (zero_sized_type (TREE_TYPE (*from_p)) && !want_value)
+  if (zero_sized_type (TREE_TYPE (*from_p))
+      && !want_value
+      /* Don't do this for calls that return addressable types, expand_call
+	 relies on those having a lhs.  */
+      && !(TREE_ADDRESSABLE (TREE_TYPE (*from_p))
+	   && TREE_CODE (*from_p) == CALL_EXPR))
     {
       gimplify_stmt (from_p, pre_p);
       gimplify_stmt (to_p, pre_p);

gcc/testsuite/ChangeLog

+2017-09-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/82159
+	* g++.dg/opt/pr82159.C: New test.
+
 2017-09-27  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	* gcc.dg/vect/pr65947-9.c: Use signed char explicitly.

gcc/testsuite/g++.dg/opt/pr82159.C

+// PR c++/82159
+// { dg-do compile }
+// { dg-options "" }
+
+template<int N>
+struct S
+{
+  ~S () {}
+  template<int M> S<M> foo () { return S<M> (); }
+  unsigned char data[N];
+};
+
+int
+main ()
+{
+  S<16> d;
+  S<0> t = d.foo<0> ();
+}