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[PR c++/82424] Dont convert dependent types
- From: Nathan Sidwell <nathan at acm dot org>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 6 Oct 2017 11:55:01 -0400
- Subject: [PR c++/82424] Dont convert dependent types
- Authentication-results: sourceware.org; auth=none
This fixes crash with -Wshadow=compatible-local, where we ended up
trying to convert to or from a dependent type. Rather than skip that
out right, I see if the types are the same (dependent or not) before
also trying convert in the non-dependent case. I suppose I could try
matching unqualified variants, but that's probably a slippery slope.
Applying to trunk.
nathan
--
Nathan Sidwell
2017-10-06 Nathan Sidwell <nathan@acm.org>
cp/
PR c++/82424
* name-lookup.c (check_local_shadow): Don't try and convert
dependent types.
testsuite/
PR c++/82424
* g++.dg/warn/pr82424.C: New.
Index: cp/name-lookup.c
===================================================================
--- cp/name-lookup.c (revision 253493)
+++ cp/name-lookup.c (working copy)
@@ -2728,7 +2728,11 @@ check_local_shadow (tree decl)
else if (warn_shadow_local)
warning_code = OPT_Wshadow_local;
else if (warn_shadow_compatible_local
- && can_convert (TREE_TYPE (old), TREE_TYPE (decl), tf_none))
+ && (same_type_p (TREE_TYPE (old), TREE_TYPE (decl))
+ || (!dependent_type_p (TREE_TYPE (decl))
+ && !dependent_type_p (TREE_TYPE (old))
+ && can_convert (TREE_TYPE (old), TREE_TYPE (decl),
+ tf_none))))
warning_code = OPT_Wshadow_compatible_local;
else
return;
Index: testsuite/g++.dg/warn/pr82424.C
===================================================================
--- testsuite/g++.dg/warn/pr82424.C (revision 0)
+++ testsuite/g++.dg/warn/pr82424.C (working copy)
@@ -0,0 +1,20 @@
+// { dg-additional-options "-Wshadow=compatible-local" }
+
+// pr c++/82424 we were trying to convert between dependent types.
+template <typename T> class a
+{
+ struct b;
+ template <typename, typename> void c ();
+};
+template <typename T>
+template <typename, typename>
+void
+a<T>::c ()
+{
+ typedef typename T::b b; // Don't go looking inside the typename
+ T thing;
+ {
+ T thing; // { dg-warning "shadows a previous local" }
+ }
+}
+