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[PATCH] Fix PR56480 aka DR374. Allow explicit specialization in enclosing namespace.
- From: Markus Trippelsdorf <markus at trippelsdorf dot de>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Jason Merrill <jason at redhat dot com>
- Date: Sat, 8 Nov 2014 12:57:21 +0100
- Subject: [PATCH] Fix PR56480 aka DR374. Allow explicit specialization in enclosing namespace.
- Authentication-results: sourceware.org; auth=none
DR374: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#374
allows explicit specialization of templates in the enclosing namespace.
This is implemented by consolidating check_specialization_namespace and
check_explicit_instantiation_namespace into a new function and
pedwarning only for C++98. Only explicit namespace qualifications are
accepted, so g++.dg/template/spec17.C is rejected. To check for this
condition have_def and in_namespace are passed through to
register_specialization() by using a bitmask.
Tested on powerpc64-unknown-linux-gnu. (Also tested by running the Boost
testsuite and building Firefox.)
OK for trunk?
Thanks again.
2014-11-08 Markus Trippelsdorf <markus@trippelsdorf.de>
gcc/cp/ChangeLog:
* decl.c (grokfndecl): Also pass through in_namespace.
* pt.c (check_instant_or_special_namespace): Consolidate
check_specialization_namespace and
check_explicit_instantiation_namespace. pedwarn only for C++98.
(maybe_process_partial_specialization): Call consolidated
function.
(register_specialization): Add flag. Only accept explicit
namespace qualification.
(check_template_variable): Call consolidated function.
(check_explicit_specialization): Likewise
(push_template_decl_real): Likewise
(tsubst_friend_function): Likewise.
(tsubst_decl): Likewise.
(do_decl_instantiation): Likewise.
(do_type_instantiation): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/template/spec17.C: Don't dg-error for C++11 and up.
* g++.dg/template/spec25.C: Likewise. Adjust regex.
* g++.dg/template/spec36.C: Don't dg-error for C++11 and up.
* g++.old-deja/g++.ns/template13.C: Likewise.
* g++.old-deja/g++.pt/explicit73.C: Likewise.
* g++.old-deja/g++.pt/lookup10.C: Likewise.
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 4abc1011e61e..931bf2c2aafc 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7855,7 +7855,8 @@ grokfndecl (tree ctype,
decl = check_explicit_specialization (orig_declarator, decl,
template_count,
2 * funcdef_flag +
- 4 * (friendp != 0));
+ 4 * (friendp != 0) +
+ 8 * (in_namespace != 0));
if (decl == error_mark_node)
return NULL_TREE;
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index fa9652f748c2..64f72e50880d 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -755,57 +755,58 @@ end_explicit_instantiation (void)
processing_explicit_instantiation = false;
}
-/* An explicit specialization or partial specialization of TMPL is being
- declared. Check that the namespace in which the specialization is
- occurring is permissible. Returns false iff it is invalid to
- specialize TMPL in the current namespace. */
+/* If specialization is true, an explicit specialization or partial
+ specialization of TMPL is being declared. Check that the namespace
+ in which the specialization is occurring is permissible. Returns
+ false iff it is invalid to specialize TMPL in the current namespace.
+ If specialization is false, TMPL is an explicit instantiation.
+ Check that it is valid to perform this explicit instantiation in
+ the current namespace. */
static bool
-check_specialization_namespace (tree tmpl)
+check_instant_or_special_namespace (tree tmpl, bool specialization)
{
tree tpl_ns = decl_namespace_context (tmpl);
- /* [tmpl.expl.spec]
-
- An explicit specialization shall be declared in the namespace of
- which the template is a member, or, for member templates, in the
- namespace of which the enclosing class or enclosing class
- template is a member. An explicit specialization of a member
- function, member class or static data member of a class template
- shall be declared in the namespace of which the class template is
- a member. */
- if (current_scope() != DECL_CONTEXT (tmpl)
- && !at_namespace_scope_p ())
- {
- error ("specialization of %qD must appear at namespace scope", tmpl);
- return false;
- }
- if (is_associated_namespace (current_namespace, tpl_ns))
- /* Same or super-using namespace. */
- return true;
- else
+ if (specialization)
{
- permerror (input_location, "specialization of %qD in different namespace", tmpl);
- permerror (input_location, " from definition of %q+#D", tmpl);
- return false;
- }
-}
+ /* [tmpl.expl.spec]
-/* SPEC is an explicit instantiation. Check that it is valid to
- perform this explicit instantiation in the current namespace. */
-
-static void
-check_explicit_instantiation_namespace (tree spec)
-{
- tree ns;
+ An explicit specialization shall be declared in the namespace of
+ which the template is a member, or, for member templates, in the
+ namespace of which the enclosing class or enclosing class
+ template is a member. An explicit specialization of a member
+ function, member class or static data member of a class template
+ shall be declared in the namespace of which the class template is
+ a member. */
+ if (current_scope () != DECL_CONTEXT (tmpl) && !at_namespace_scope_p ())
+ {
+ error ("specialization of %qD must appear at namespace scope", tmpl);
+ return false;
+ }
+ if (is_associated_namespace (current_namespace, tpl_ns))
+ /* Same or super-using namespace. */
+ return true;
+ /* DR374: explicit specializations of templates in an enclosing
+ namespace are allowed. */
+ else if (cxx_dialect < cxx11)
+ {
+ pedwarn (input_location, OPT_Wpedantic,
+ "specialization of %qD in different namespace", tmpl);
+ pedwarn (input_location, OPT_Wpedantic, " from definition of %q+#D",
+ tmpl);
+ }
+ }
/* DR 275: An explicit instantiation shall appear in an enclosing
namespace of its template. */
- ns = decl_namespace_context (spec);
- if (!is_ancestor (current_namespace, ns))
- permerror (input_location, "explicit instantiation of %qD in namespace %qD "
+ if (!is_ancestor (current_namespace, tpl_ns))
+ permerror (input_location,
+ "explicit instantiation of %qD in namespace %qD "
"(which does not enclose namespace %qD)",
- spec, current_namespace, ns);
+ tmpl, current_namespace, tpl_ns);
+
+ return false;
}
/* The TYPE is being declared. If it is a template type, that means it
@@ -859,7 +860,8 @@ maybe_process_partial_specialization (tree type)
if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
&& !COMPLETE_TYPE_P (type))
{
- if (!check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type))
+ if (!check_instant_or_special_namespace (
+ CLASSTYPE_TI_TEMPLATE (type), true)
&& !at_namespace_scope_p ())
return error_mark_node;
SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
@@ -1338,14 +1340,22 @@ is_specialization_of_friend (tree decl, tree friend_decl)
is actually just a friend declaration. Returns SPEC, or an
equivalent prior declaration, if available.
+ FLAGS is a bitmask consisting of the following flags:
+
+ 2: The function has a definition.
+ 4: The function is a friend.
+ 8: The function has explicit namespace qualification.
+
We also store instantiations of field packs in the hash table, even
though they are not themselves templates, to make lookup easier. */
static tree
register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
- hashval_t hash)
+ hashval_t hash, int flags)
{
tree fn;
+ int have_def = flags & 2;
+ int in_namespace = flags & 8;
spec_entry **slot = NULL;
spec_entry elt;
@@ -1454,7 +1464,15 @@ register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
DECL_DELETED_FN (clone)
= DECL_DELETED_FN (fn);
}
- check_specialization_namespace (tmpl);
+
+
+ if (!is_associated_namespace (current_namespace,
+ decl_namespace_context (tmpl))
+ && !have_def && !in_namespace)
+ error ("no function template matches function "
+ "template specialization");
+
+ check_instant_or_special_namespace (tmpl, true);
return fn;
}
@@ -1476,7 +1494,7 @@ register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
/* A specialization must be declared in the same namespace as the
template it is specializing. */
if (DECL_P (spec) && DECL_TEMPLATE_SPECIALIZATION (spec)
- && !check_specialization_namespace (tmpl))
+ && !check_instant_or_special_namespace (tmpl, true))
DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
@@ -2347,6 +2365,7 @@ check_template_variable (tree decl)
2: The function has a definition.
4: The function is a friend.
+ 8: The function has explicit namespace qualification.
The TEMPLATE_COUNT is the number of references to qualifying
template classes that appeared in the name of the function. For
@@ -2741,7 +2760,7 @@ check_explicit_specialization (tree declarator,
DECL_CONTEXT (parm) = result;
}
return register_specialization (tmpl, gen_tmpl, targs,
- is_friend, 0);
+ is_friend, 0, 0);
}
/* Set up the DECL_TEMPLATE_INFO for DECL. */
@@ -2821,7 +2840,7 @@ check_explicit_specialization (tree declarator,
/* Register this specialization so that we can find it
again. */
- decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
+ decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0, flags);
/* A 'structor should already have clones. */
gcc_assert (decl == error_mark_node
@@ -4930,7 +4949,7 @@ push_template_decl_real (tree decl, bool is_friend)
register_specialization (new_tmpl,
most_general_template (tmpl),
args,
- is_friend, 0);
+ is_friend, 0, 0);
return decl;
}
@@ -8688,7 +8707,7 @@ tsubst_friend_function (tree decl, tree args)
DECL_TI_ARGS (spec));
register_specialization
- (spec, new_template, DECL_TI_ARGS (spec), true, 0);
+ (spec, new_template, DECL_TI_ARGS (spec), true, 0, 0);
}
DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
@@ -10614,7 +10633,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
/* Record this non-type partial instantiation. */
register_specialization (r, t,
DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
- false, hash);
+ false, hash, 0);
}
break;
@@ -10822,7 +10841,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
SET_DECL_IMPLICIT_INSTANTIATION (r);
tree new_r
- = register_specialization (r, gen_tmpl, argvec, false, hash);
+ = register_specialization (r, gen_tmpl, argvec, false, hash, 0);
if (new_r != r)
/* We instantiated this while substituting into
the type earlier (template/friend54.C). */
@@ -11094,7 +11113,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
SET_ARGUMENT_PACK_ARGS (pack, vec);
SET_ARGUMENT_PACK_ARGS (tpack, expanded_types);
TREE_TYPE (pack) = tpack;
- register_specialization (pack, t, args, false, 0);
+ register_specialization (pack, t, args, false, 0, 0);
}
}
break;
@@ -11320,7 +11339,7 @@ tsubst_decl (tree t, tree args, tsubst_flags_t complain)
processing here. */
DECL_EXTERNAL (r) = 1;
- register_specialization (r, gen_tmpl, argvec, false, hash);
+ register_specialization (r, gen_tmpl, argvec, false, hash, 0);
DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
SET_DECL_IMPLICIT_INSTANTIATION (r);
}
@@ -19433,7 +19452,7 @@ do_decl_instantiation (tree decl, tree storage)
else
error ("storage class %qD applied to template instantiation", storage);
- check_explicit_instantiation_namespace (result);
+ check_instant_or_special_namespace (result, false);
mark_decl_instantiated (result, extern_p);
if (! extern_p)
instantiate_decl (result, /*defer_ok=*/1,
@@ -19581,7 +19600,7 @@ do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
return;
}
- check_explicit_instantiation_namespace (TYPE_NAME (t));
+ check_instant_or_special_namespace (TYPE_NAME (t), false);
mark_class_instantiated (t, extern_p);
if (nomem_p)
diff --git a/gcc/testsuite/g++.dg/template/spec17.C b/gcc/testsuite/g++.dg/template/spec17.C
index 237557684238..849178920012 100644
--- a/gcc/testsuite/g++.dg/template/spec17.C
+++ b/gcc/testsuite/g++.dg/template/spec17.C
@@ -1,7 +1,7 @@
// PR c++/16224
namespace io {
- template <typename> int foo(); // { dg-error "" }
+ template <typename> int foo(); // { dg-error "" "" { target { ! c++11 } } }
}
using namespace io;
diff --git a/gcc/testsuite/g++.dg/template/spec25.C b/gcc/testsuite/g++.dg/template/spec25.C
index 385d19ada0c4..c3836261f6af 100644
--- a/gcc/testsuite/g++.dg/template/spec25.C
+++ b/gcc/testsuite/g++.dg/template/spec25.C
@@ -1,10 +1,10 @@
namespace N {
template <typename T>
struct S {
- void f() {} // { dg-error "definition" }
+ void f() {} // { dg-error "definition" "" { target { ! c++11 } } }
};
}
namespace K {
- template <> void N::S<char>::f() {} // { dg-error "different namespace" }
+ template <> void N::S<char>::f() {} // { dg-error "namespace" }
}
diff --git a/gcc/testsuite/g++.dg/template/spec36.C b/gcc/testsuite/g++.dg/template/spec36.C
index 7e8dc5241d9f..d9c57824b7e5 100644
--- a/gcc/testsuite/g++.dg/template/spec36.C
+++ b/gcc/testsuite/g++.dg/template/spec36.C
@@ -8,9 +8,9 @@ struct basic_string
namespace MyNS {
class MyClass {
template <typename T>
- T test() { } /* { dg-error "from definition" } */
+ T test() { } /* { dg-error "from definition" "" { target { ! c++11 } } } */
};
}
template <>
-basic_string MyNS::MyClass::test() /* { dg-error "specialization of" } */
+basic_string MyNS::MyClass::test() /* { dg-error "specialization of" "" { target { ! c++11 } } } */
{ return 1; }
diff --git a/gcc/testsuite/g++.old-deja/g++.ns/template13.C b/gcc/testsuite/g++.old-deja/g++.ns/template13.C
index a9559c7153b6..0c99e74dc466 100644
--- a/gcc/testsuite/g++.old-deja/g++.ns/template13.C
+++ b/gcc/testsuite/g++.old-deja/g++.ns/template13.C
@@ -4,7 +4,7 @@ namespace bar
{
// trick it to provide some prior declaration
template<class T>
- void foo(); // { dg-error "definition" }
+ void foo(); // { dg-error "definition" "" { target { ! c++11 } } }
template<class T>class X; // { dg-message "note: previous declaration" }
}
@@ -15,7 +15,7 @@ bar::foo(T const &a) // { dg-error "" "" { xfail *-*-* } } not declared in b
return a;
}
-template<> void bar::foo<int>() // { dg-error "different namespace" }
+template<> void bar::foo<int>() // { dg-error "different namespace" "" { target { ! c++11 } } }
{
}
diff --git a/gcc/testsuite/g++.old-deja/g++.pt/explicit73.C b/gcc/testsuite/g++.old-deja/g++.pt/explicit73.C
index 1d83e3468289..bcf4fe7f21a5 100644
--- a/gcc/testsuite/g++.old-deja/g++.pt/explicit73.C
+++ b/gcc/testsuite/g++.old-deja/g++.pt/explicit73.C
@@ -7,9 +7,9 @@
// the template
namespace N {
- template <class T> class foo; // { dg-error "" } referenced below
+ template <class T> class foo; // { dg-error "" "" { target { ! c++11 } } } referenced below
}
using namespace N;
-template <> class foo<void>; // { dg-error "" } invalid specialization
+template <> class foo<void>; // { dg-error "" "" { target { ! c++11 } } } invalid specialization
diff --git a/gcc/testsuite/g++.old-deja/g++.pt/lookup10.C b/gcc/testsuite/g++.old-deja/g++.pt/lookup10.C
index 1c04250fc3c0..0ed5dbe42c89 100644
--- a/gcc/testsuite/g++.old-deja/g++.pt/lookup10.C
+++ b/gcc/testsuite/g++.old-deja/g++.pt/lookup10.C
@@ -13,8 +13,8 @@ namespace Outer {
namespace Core = Core_Real;
namespace Core_Real {
- template<class T> void Foo (T *) {} // { dg-error "definition" }
+ template<class T> void Foo (T *) {} // { dg-error "definition" "" { target { ! c++11 } } }
}
- template<> void Core::Foo<> (Render_Real::Type *) {} // { dg-error "" }
+ template<> void Core::Foo<> (Render_Real::Type *) {} // { dg-error "" "" { target { ! c++11 } } }
}
--
Markus