Re: [C++ Patch] PR 65370

[Paolo Carlini]

Hi,

On 03/10/2015 07:10 PM, Jason Merrill wrote:

Ah. So here we can ignore any template instantiation or specialization, with a comment that check_explicit_specialization will handle them. But I suspect that checking the decl itself will be better; I would expect checking the context to lead you to accept

template<> class C<int> {
  template <typename U>
  C(const C<U>&, bool);
};

template <typename U> C<int>::C(const C<U>&, bool = false);

Since here C<int> is a specialization of C, but the constructor is not itself a partial instantiation.

Indeed you are right. Therefore I'm finishing testing the below.

Thanks!
Paolo.

////////////////////////

/cp
2015-03-10  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/65370
        * decl.c (duplicate_decls): Call check_redeclaration_no_default_args
        only if the location of newdecl doesn't match the location of olddecl.

/testsuite
2015-03-10  Paolo Carlini  <paolo.carl...@oracle.com>

        PR c++/65370
        * g++.dg/other/default11.C: New.
        * g++.dg/other/default12.C: Likewise.

Index: cp/decl.c
===================================================================
--- cp/decl.c   (revision 221317)
+++ cp/decl.c   (working copy)
@@ -1922,7 +1922,9 @@ duplicate_decls (tree newdecl, tree olddecl, bool
        {
          /* Per C++11 8.3.6/4, default arguments cannot be added in later
             declarations of a function template.  */
-         check_redeclaration_no_default_args (newdecl);
+         if (DECL_SOURCE_LOCATION (newdecl)
+             != DECL_SOURCE_LOCATION (olddecl))
+           check_redeclaration_no_default_args (newdecl);
 
          check_default_args (newdecl);
 
Index: testsuite/g++.dg/other/default11.C
===================================================================
--- testsuite/g++.dg/other/default11.C  (revision 0)
+++ testsuite/g++.dg/other/default11.C  (working copy)
@@ -0,0 +1,11 @@
+// PR c++/65370
+
+template <typename> class C
+{
+  template <typename U>
+  C(const C<U>&, bool = false);
+};
+
+template <>
+template <typename U>
+C<int>::C(const C<U>&, bool);
Index: testsuite/g++.dg/other/default12.C
===================================================================
--- testsuite/g++.dg/other/default12.C  (revision 0)
+++ testsuite/g++.dg/other/default12.C  (working copy)
@@ -0,0 +1,16 @@
+// PR c++/65370
+
+template <typename> class C
+{
+  template <typename U>
+  C(const C<U>&, bool = false);
+};
+
+template<>
+class C<int>
+{
+  template <typename U>
+  C(const C<U>&, bool);
+};
+
+template <typename U> C<int>::C(const C<U>&, bool = false) { }  // { dg-error 
"default arguments" }