This ICE happens when we try and figure if an unresolved auto type is
compatible with a previous binding. With the addition of auto, we're
now checking too early, but that's a harder problem. This fixes the
ICE, but the downside is we don't warn at all, if the auto resolves to a
compatible type. But that's not a new problem.
Applying to trunk and gcc-8
nathan
--
Nathan Sidwell
2018-09-18 Nathan Sidwell <nat...@acm.org>
PR c++/86881
cp/
* name-lookup.c (check_local_shadow): Ignore auto types.
testsuite/
* g++.dg/warn/pr86881.C: New.
Index: gcc/cp/name-lookup.c
===================================================================
--- gcc/cp/name-lookup.c (revision 264371)
+++ gcc/cp/name-lookup.c (working copy)
@@ -2764,6 +2764,13 @@ check_local_shadow (tree decl)
&& (same_type_p (TREE_TYPE (old), TREE_TYPE (decl))
|| (!dependent_type_p (TREE_TYPE (decl))
&& !dependent_type_p (TREE_TYPE (old))
+ /* If the new decl uses auto, we don't yet know
+ its type (the old type cannot be using auto
+ at this point, without also being
+ dependent). This is an indication we're
+ (now) doing the shadow checking too
+ early. */
+ && !type_uses_auto (TREE_TYPE (decl))
&& can_convert (TREE_TYPE (old), TREE_TYPE (decl),
tf_none))))
warning_code = OPT_Wshadow_compatible_local;
Index: gcc/testsuite/g++.dg/warn/pr86881.C
===================================================================
--- gcc/testsuite/g++.dg/warn/pr86881.C (revision 0)
+++ gcc/testsuite/g++.dg/warn/pr86881.C (working copy)
@@ -0,0 +1,20 @@
+// PR c++/86881 ICE with shadow warning
+// { dg-do compile { c++11 } }
+// { dg-additional-options { -Wshadow-compatible-local } }}
+
+void a() {
+ auto b([] {});
+ {
+ auto b = 0;
+ }
+}
+
+struct Proxy { };
+
+void Two ()
+{
+ auto my = Proxy ();
+ {
+ auto my = Proxy (); // { dg-warning "shadows" "" { xfail *-*-* } }
+ };
+}
