I have tested this with the full suite on Linux-PPC64. It works otherwise fine,
but there's one snag: 20_util/unique_ptr/specialized_algorithms/swap_cxx17.cc
fails, and it looks like the trait ends up instantiating the definition
of a destructor, which then ends up being hard-error ill-formed.
That is, we have
struct C { };
void swap(C&, C&) = delete;
static_assert( !std::is_swappable_v<std::unique_ptr<int, C>> );
struct D { D(D&&) = delete; };
static_assert( !std::is_swappable_v<std::unique_ptr<int, D>> );
The destructor definitions of unique_ptr<int, C> and unique_ptr<int D>
are not valid because that destructor will try to call an operator()
on those deleters, and they don't have that operator.
The existing library implementation of is_constructible doesn't
instantiate the destructor definitions, or if it does, they don't cause
a hard error. This intrinsic trait approach behaves differently, and I would
welcome any help fixing that problem.
2017-05-12 Ville Voutilainen <ville.voutilai...@gmail.com>
c-family/
Implement new C++ intrinsics __is_assignable and __is_constructible.
* c-common.c (__is_assignable, __is_constructible): New.
* c-common.h (RID_IS_ASSIGNABLE, RID_IS_CONSTRUCTIBLE): Likewise.
cp/
Implement new C++ intrinsics __is_assignable and __is_constructible.
* cp-tree.h (CPTK_IS_ASSIGNABLE, CPTK_IS_CONSTRUCTIBLE): New.
(is_xible): New.
* cxx-pretty-print.c (pp_cxx_trait_expression): Handle
CPTK_IS_ASSIGNABLE and CPTK_IS_CONSTRUCTIBLE.
* method.c (is_xible_helper): New.
(is_trivially_xible): Adjust.
(is_xible): New.
* parser.c (cp_parser_primary_expression): Handle
RID_IS_ASSIGNABLE and RID_IS_CONSTRUCTIBLE.
(cp_parser_trait_expr): Likewise.
* semantics.c (trait_expr_value): Handle
CPTK_IS_ASSIGNABLE and CPTK_IS_CONSTRUCTIBLE.
libstdc++-v3/
Implement new C++ intrinsics __is_assignable and __is_constructible.
* include/std/type_traits (__do_is_static_castable_impl): Remove.
(__is_static_castable_impl, __is_static_castable_safe): Likewise.
(__is_static_castable, __do_is_direct_constructible_impl): Likewise.
(__is_direct_constructible_impl): Likewise.
(__is_direct_constructible_new_safe): Likewise.
(__is_base_to_derived_ref, __is_lvalue_to_rvalue_ref): Likewise.
(__is_direct_constructible_ref_cast): Likewise.
(__is_direct_constructible_new, __is_direct_constructible): Likewise.
(__do_is_nary_constructible_impl): Likewise.
(__is_nary_constructible_impl, __is_nary_constructible): Likewise.
(__is_constructible_impl): Likewise.
(is_constructible): Call the intrinsic.
(__is_assignable_helper): Remove.
(is_assignable): Call the intrinsic.
(is_trivially_constructible): Likewise.
(is_trivially_assignable): Likewise.
(testsuite/20_util/declval/requirements/1_neg.cc): Adjust.
(testsuite/20_util/make_signed/requirements/typedefs_neg.cc): Likewise.
(testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc):
Likewise.
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index ad686d2..369e112 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -514,6 +514,8 @@ const struct c_common_resword c_common_reswords[] =
{ "volatile", RID_VOLATILE, 0 },
{ "wchar_t", RID_WCHAR, D_CXXONLY },
{ "while", RID_WHILE, 0 },
+ { "__is_assignable", RID_IS_ASSIGNABLE, D_CXXONLY },
+ { "__is_constructible", RID_IS_CONSTRUCTIBLE, D_CXXONLY },
/* C++ transactional memory. */
{ "synchronized", RID_SYNCHRONIZED, D_CXX_OBJC | D_TRANSMEM },
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 9e3982d..a986056 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -172,6 +172,7 @@ enum rid
RID_IS_TRIVIALLY_ASSIGNABLE, RID_IS_TRIVIALLY_CONSTRUCTIBLE,
RID_IS_TRIVIALLY_COPYABLE,
RID_IS_UNION, RID_UNDERLYING_TYPE,
+ RID_IS_ASSIGNABLE, RID_IS_CONSTRUCTIBLE,
/* C++11 */
RID_CONSTEXPR, RID_DECLTYPE, RID_NOEXCEPT, RID_NULLPTR, RID_STATIC_ASSERT,
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 09b1364..154ba3c 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -927,7 +927,9 @@ enum cp_trait_kind
CPTK_IS_TRIVIALLY_CONSTRUCTIBLE,
CPTK_IS_TRIVIALLY_COPYABLE,
CPTK_IS_UNION,
- CPTK_UNDERLYING_TYPE
+ CPTK_UNDERLYING_TYPE,
+ CPTK_IS_ASSIGNABLE,
+ CPTK_IS_CONSTRUCTIBLE
};
/* The types that we are processing. */
@@ -6112,6 +6114,7 @@ extern void use_thunk (tree,
bool);
extern bool trivial_fn_p (tree);
extern tree forward_parm (tree);
extern bool is_trivially_xible (enum tree_code, tree, tree);
+extern bool is_xible (enum tree_code, tree, tree);
extern tree get_defaulted_eh_spec (tree);
extern tree unevaluated_noexcept_spec (void);
extern void after_nsdmi_defaulted_late_checks (tree);
diff --git a/gcc/cp/cxx-pretty-print.c b/gcc/cp/cxx-pretty-print.c
index f76c30a..71d149a 100644
--- a/gcc/cp/cxx-pretty-print.c
+++ b/gcc/cp/cxx-pretty-print.c
@@ -2634,6 +2634,12 @@ pp_cxx_trait_expression (cxx_pretty_printer *pp, tree t)
case CPTK_IS_LITERAL_TYPE:
pp_cxx_ws_string (pp, "__is_literal_type");
break;
+ case CPTK_IS_ASSIGNABLE:
+ pp_cxx_ws_string (pp, "__is_assignable");
+ break;
+ case CPTK_IS_CONSTRUCTIBLE:
+ pp_cxx_ws_string (pp, "__is_constructible");
+ break;
default:
gcc_unreachable ();
diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index 99e98cc..a377321 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -1200,22 +1200,36 @@ constructible_expr (tree to, tree from)
return expr;
}
-/* Returns true iff TO is trivially assignable (if CODE is MODIFY_EXPR) or
+/* Returns a tree iff TO is assignable (if CODE is MODIFY_EXPR) or
constructible (otherwise) from FROM, which is a single type for
assignment or a list of types for construction. */
-bool
-is_trivially_xible (enum tree_code code, tree to, tree from)
+static tree
+is_xible_helper (enum tree_code code, tree to, tree from, bool trivial)
{
- if (VOID_TYPE_P (to))
- return false;
+ if (VOID_TYPE_P (to) || ABSTRACT_CLASS_TYPE_P (to)
+ || (from && FUNC_OR_METHOD_TYPE_P (from)
+ && (TYPE_READONLY (from) || FUNCTION_REF_QUALIFIED (from))))
+ return error_mark_node;
tree expr;
if (code == MODIFY_EXPR)
expr = assignable_expr (to, from);
- else if (from && TREE_CHAIN (from))
- return false; // only 0- and 1-argument ctors can be trivial
+ else if (trivial && from && TREE_CHAIN (from))
+ return error_mark_node; // only 0- and 1-argument ctors can be trivial
else
expr = constructible_expr (to, from);
+ return expr;
+}
+
+/* Returns true iff TO is trivially assignable (if CODE is MODIFY_EXPR) or
+ constructible (otherwise) from FROM, which is a single type for
+ assignment or a list of types for construction. */
+
+bool
+is_trivially_xible (enum tree_code code, tree to, tree from)
+{
+ tree expr;
+ expr = is_xible_helper (code, to, from, /*trivial*/true);
if (expr == error_mark_node)
return false;
@@ -1223,6 +1237,19 @@ is_trivially_xible (enum tree_code code, tree to, tree
from)
return !nt;
}
+/* Returns true iff TO is assignable (if CODE is MODIFY_EXPR) or
+ constructible (otherwise) from FROM, which is a single type for
+ assignment or a list of types for construction. */
+
+bool
+is_xible (enum tree_code code, tree to, tree from)
+{
+ tree expr = is_xible_helper (code, to, from, /*trivial*/false);
+ if (expr == error_mark_node)
+ return false;
+ return !!expr;
+}
+
/* Subroutine of synthesized_method_walk. Update SPEC_P, TRIVIAL_P and
DELETED_P or give an error message MSG with argument ARG. */
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 17d2679..5986dd9 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -5135,6 +5135,8 @@ cp_parser_primary_expression (cp_parser *parser,
case RID_IS_TRIVIALLY_CONSTRUCTIBLE:
case RID_IS_TRIVIALLY_COPYABLE:
case RID_IS_UNION:
+ case RID_IS_ASSIGNABLE:
+ case RID_IS_CONSTRUCTIBLE:
return cp_parser_trait_expr (parser, token->keyword);
// C++ concepts
@@ -9686,6 +9688,14 @@ cp_parser_trait_expr (cp_parser* parser, enum rid
keyword)
case RID_DIRECT_BASES:
kind = CPTK_DIRECT_BASES;
break;
+ case RID_IS_ASSIGNABLE:
+ kind = CPTK_IS_ASSIGNABLE;
+ binary = true;
+ break;
+ case RID_IS_CONSTRUCTIBLE:
+ kind = CPTK_IS_CONSTRUCTIBLE;
+ variadic = true;
+ break;
default:
gcc_unreachable ();
}
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 7b2c101..f9f402e 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -9209,6 +9209,12 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree
type2)
case CPTK_IS_UNION:
return type_code1 == UNION_TYPE;
+ case CPTK_IS_ASSIGNABLE:
+ return is_xible (MODIFY_EXPR, type1, type2);
+
+ case CPTK_IS_CONSTRUCTIBLE:
+ return is_xible (INIT_EXPR, type1, type2);
+
default:
gcc_unreachable ();
return false;
@@ -9282,6 +9288,10 @@ finish_trait_expr (cp_trait_kind kind, tree type1, tree
type2)
return error_mark_node;
break;
+ case CPTK_IS_ASSIGNABLE:
+ case CPTK_IS_CONSTRUCTIBLE:
+ break;
+
case CPTK_IS_TRIVIALLY_ASSIGNABLE:
case CPTK_IS_TRIVIALLY_CONSTRUCTIBLE:
if (!check_trait_type (type1)
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index aac7cff..00f647b 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -924,213 +924,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public __is_default_constructible_safe<_Tp>::type
{ };
-
- // Implementation of is_constructible.
-
- // The hardest part of this trait is the binary direct-initialization
- // case, because we hit into a functional cast of the form T(arg).
- // This implementation uses different strategies depending on the
- // target type to reduce the test overhead as much as possible:
- //
- // a) For a reference target type, we use a static_cast expression
- // modulo its extra cases.
- //
- // b) For a non-reference target type we use a ::new expression.
- struct __do_is_static_castable_impl
- {
- template<typename _From, typename _To, typename
- = decltype(static_cast<_To>(declval<_From>()))>
- static true_type __test(int);
-
- template<typename, typename>
- static false_type __test(...);
- };
-
- template<typename _From, typename _To>
- struct __is_static_castable_impl
- : public __do_is_static_castable_impl
- {
- typedef decltype(__test<_From, _To>(0)) type;
- };
-
- template<typename _From, typename _To>
- struct __is_static_castable_safe
- : public __is_static_castable_impl<_From, _To>::type
- { };
-
- // __is_static_castable
- template<typename _From, typename _To>
- struct __is_static_castable
- : public integral_constant<bool, (__is_static_castable_safe<
- _From, _To>::value)>
- { };
-
- // Implementation for non-reference types. To meet the proper
- // variable definition semantics, we also need to test for
- // is_destructible in this case.
- // This form should be simplified by a single expression:
- // ::delete ::new _Tp(declval<_Arg>()), see c++/51222.
- struct __do_is_direct_constructible_impl
- {
- template<typename _Tp, typename _Arg, typename
- = decltype(::new _Tp(declval<_Arg>()))>
- static true_type __test(int);
-
- template<typename, typename>
- static false_type __test(...);
- };
-
- template<typename _Tp, typename _Arg>
- struct __is_direct_constructible_impl
- : public __do_is_direct_constructible_impl
- {
- typedef decltype(__test<_Tp, _Arg>(0)) type;
- };
-
- template<typename _Tp, typename _Arg>
- struct __is_direct_constructible_new_safe
- : public __and_<is_destructible<_Tp>,
- __is_direct_constructible_impl<_Tp, _Arg>>
- { };
-
- template<typename, typename>
- struct is_same;
-
- template<typename, typename>
- struct is_base_of;
-
- template<typename>
- struct remove_reference;
-
- template<typename _From, typename _To, bool
- = __not_<__or_<is_void<_From>,
- is_function<_From>>>::value>
- struct __is_base_to_derived_ref;
-
- template<typename _Tp, typename... _Args>
- struct is_constructible;
-
- // Detect whether we have a downcast situation during
- // reference binding.
- template<typename _From, typename _To>
- struct __is_base_to_derived_ref<_From, _To, true>
- {
- typedef typename remove_cv<typename remove_reference<_From
- >::type>::type __src_t;
- typedef typename remove_cv<typename remove_reference<_To
- >::type>::type __dst_t;
- typedef __and_<__not_<is_same<__src_t, __dst_t>>,
- is_base_of<__src_t, __dst_t>,
- __not_<is_constructible<__dst_t, _From>>> type;
- static constexpr bool value = type::value;
- };
-
- template<typename _From, typename _To>
- struct __is_base_to_derived_ref<_From, _To, false>
- : public false_type
- { };
-
- template<typename _From, typename _To, bool
- = __and_<is_lvalue_reference<_From>,
- is_rvalue_reference<_To>>::value>
- struct __is_lvalue_to_rvalue_ref;
-
- // Detect whether we have an lvalue of non-function type
- // bound to a reference-compatible rvalue-reference.
- template<typename _From, typename _To>
- struct __is_lvalue_to_rvalue_ref<_From, _To, true>
- {
- typedef typename remove_cv<typename remove_reference<
- _From>::type>::type __src_t;
- typedef typename remove_cv<typename remove_reference<
- _To>::type>::type __dst_t;
- typedef __and_<__not_<is_function<__src_t>>,
- __or_<is_same<__src_t, __dst_t>,
- is_base_of<__dst_t, __src_t>>> type;
- static constexpr bool value = type::value;
- };
-
- template<typename _From, typename _To>
- struct __is_lvalue_to_rvalue_ref<_From, _To, false>
- : public false_type
- { };
-
- // Here we handle direct-initialization to a reference type as
- // equivalent to a static_cast modulo overshooting conversions.
- // These are restricted to the following conversions:
- // a) A base class value to a derived class reference
- // b) An lvalue to an rvalue-reference of reference-compatible
- // types that are not functions
- template<typename _Tp, typename _Arg>
- struct __is_direct_constructible_ref_cast
- : public __and_<__is_static_castable<_Arg, _Tp>,
- __not_<__or_<__is_base_to_derived_ref<_Arg, _Tp>,
- __is_lvalue_to_rvalue_ref<_Arg, _Tp>
- >>>
- { };
-
- template<typename _Tp, typename _Arg>
- struct __is_direct_constructible_new
- : public conditional<is_reference<_Tp>::value,
- __is_direct_constructible_ref_cast<_Tp, _Arg>,
- __is_direct_constructible_new_safe<_Tp, _Arg>
- >::type
- { };
-
- template<typename _Tp, typename _Arg>
- struct __is_direct_constructible
- : public __is_direct_constructible_new<_Tp, _Arg>::type
- { };
-
- // Since default-construction and binary direct-initialization have
- // been handled separately, the implementation of the remaining
- // n-ary construction cases is rather straightforward. We can use
- // here a functional cast, because array types are excluded anyway
- // and this form is never interpreted as a C cast.
- struct __do_is_nary_constructible_impl
- {
- template<typename _Tp, typename... _Args, typename
- = decltype(_Tp(declval<_Args>()...))>
- static true_type __test(int);
-
- template<typename, typename...>
- static false_type __test(...);
- };
-
- template<typename _Tp, typename... _Args>
- struct __is_nary_constructible_impl
- : public __do_is_nary_constructible_impl
- {
- typedef decltype(__test<_Tp, _Args...>(0)) type;
- };
-
- template<typename _Tp, typename... _Args>
- struct __is_nary_constructible
- : public __is_nary_constructible_impl<_Tp, _Args...>::type
- {
- static_assert(sizeof...(_Args) > 1,
- "Only useful for > 1 arguments");
- };
-
- template<typename _Tp, typename... _Args>
- struct __is_constructible_impl
- : public __is_nary_constructible<_Tp, _Args...>
- { };
-
- template<typename _Tp, typename _Arg>
- struct __is_constructible_impl<_Tp, _Arg>
- : public __is_direct_constructible<_Tp, _Arg>
- { };
-
- template<typename _Tp>
- struct __is_constructible_impl<_Tp>
- : public is_default_constructible<_Tp>
- { };
-
/// is_constructible
template<typename _Tp, typename... _Args>
struct is_constructible
- : public __is_constructible_impl<_Tp, _Args...>::type
+ : public __bool_constant<__is_constructible(_Tp, _Args...)>
{ };
template<typename _Tp, bool = __is_referenceable<_Tp>::value>
@@ -1255,26 +1052,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public __is_nothrow_move_constructible_impl<_Tp>
{ };
- template<typename _Tp, typename _Up>
- class __is_assignable_helper
- {
- template<typename _Tp1, typename _Up1,
- typename = decltype(declval<_Tp1>() = declval<_Up1>())>
- static true_type
- __test(int);
-
- template<typename, typename>
- static false_type
- __test(...);
-
- public:
- typedef decltype(__test<_Tp, _Up>(0)) type;
- };
-
/// is_assignable
template<typename _Tp, typename _Up>
struct is_assignable
- : public __is_assignable_helper<_Tp, _Up>::type
+ : public __bool_constant<__is_assignable(_Tp, _Up)>
{ };
template<typename _Tp, bool = __is_referenceable<_Tp>::value>
@@ -1364,8 +1145,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// is_trivially_constructible
template<typename _Tp, typename... _Args>
struct is_trivially_constructible
- : public __and_<is_constructible<_Tp, _Args...>, integral_constant<bool,
- __is_trivially_constructible(_Tp, _Args...)>>
+ : public __bool_constant<__is_trivially_constructible(_Tp, _Args...)>
{ };
/// is_trivially_default_constructible
@@ -1423,9 +1203,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// is_trivially_assignable
template<typename _Tp, typename _Up>
struct is_trivially_assignable
- : public __and_<is_assignable<_Tp, _Up>,
- integral_constant<bool,
- __is_trivially_assignable(_Tp, _Up)>>
+ : public __bool_constant<__is_trivially_assignable(_Tp, _Up)>
{ };
/// is_trivially_copy_assignable
diff --git a/libstdc++-v3/testsuite/20_util/declval/requirements/1_neg.cc
b/libstdc++-v3/testsuite/20_util/declval/requirements/1_neg.cc
index dc9daeb..0c5599d 100644
--- a/libstdc++-v3/testsuite/20_util/declval/requirements/1_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/declval/requirements/1_neg.cc
@@ -18,7 +18,7 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
-// { dg-error "static assertion failed" "" { target *-*-* } 2259 }
+// { dg-error "static assertion failed" "" { target *-*-* } 2037 }
#include <utility>
diff --git
a/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc
b/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc
index 664fb70..4b83764 100644
--- a/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/make_signed/requirements/typedefs_neg.cc
@@ -47,4 +47,4 @@ void test01()
// { dg-error "required from here" "" { target *-*-* } 39 }
// { dg-error "required from here" "" { target *-*-* } 41 }
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1924 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1702 }
diff --git
a/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc
b/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc
index 6d64717..d77b023 100644
--- a/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc
@@ -47,5 +47,5 @@ void test01()
// { dg-error "required from here" "" { target *-*-* } 39 }
// { dg-error "required from here" "" { target *-*-* } 41 }
-// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1820 }
-// { dg-error "declaration of" "" { target *-*-* } 1777 }
+// { dg-error "invalid use of incomplete type" "" { target *-*-* } 1598 }
+// { dg-error "declaration of" "" { target *-*-* } 1555 }
