Hi,
here, for an incomplete type we ICE pretty soon in
find_decomp_class_base. Comparing to other cases too, I convinced myself
that trying to complete the type is Ok. Also, it seems that in these
functions we want to talk about structured binding and use an
appropriate location, thus no complete_type_or_maybe_complain. Tested
x86_64-linux.
Thanks, Paolo.
/////////////////////
/cp
2018-04-06 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/85227
* decl.c (find_decomp_class_base): Try to complete the type
and give an error if that fails.
/testsuite
2018-04-06 Paolo Carlini <paolo.carl...@oracle.com>
PR c++/85227
* g++.dg/cpp1z/decomp42.C: New.
Index: cp/decl.c
===================================================================
--- cp/decl.c (revision 259156)
+++ cp/decl.c (working copy)
@@ -7310,6 +7310,13 @@ cp_finish_decl (tree decl, tree init, bool init_co
static tree
find_decomp_class_base (location_t loc, tree type, tree ret)
{
+ if (!COMPLETE_TYPE_P (complete_type (type)))
+ {
+ error_at (loc, "structured binding refers to incomplete class type %qT",
+ type);
+ return error_mark_node;
+ }
+
bool member_seen = false;
for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
if (TREE_CODE (field) != FIELD_DECL
Index: testsuite/g++.dg/cpp1z/decomp42.C
===================================================================
--- testsuite/g++.dg/cpp1z/decomp42.C (nonexistent)
+++ testsuite/g++.dg/cpp1z/decomp42.C (working copy)
@@ -0,0 +1,10 @@
+// PR c++/85227
+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+extern struct A a;
+
+template<int> void foo()
+{
+ auto[i] = a; // { dg-error "incomplete" }
+} // { dg-warning "structured bindings only available with -std=c..17 or
-std=gnu..17" "" { target c++14_down } .-1 }
