c++: Implement __is_member_pointer built-in trait

This patch implements built-in trait for std::is_member_pointer.

gcc/cp/ChangeLog:

	* cp-trait.def: Define __is_member_pointer.
	* constraint.cc (diagnose_trait_expr): Handle
	CPTK_IS_MEMBER_POINTER.
	* semantics.cc (trait_expr_value): Likewise.
	(finish_trait_expr): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/has-builtin-1.C: Test existence of
	__is_member_pointer.
	* g++.dg/ext/is_member_pointer.C: New test.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>

5 files changed, 41 insertions, 0 deletions

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 062dc40..fb150e0 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3758,6 +3758,9 @@ diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_LITERAL_TYPE:
       inform (loc, "  %qT is not a literal type", t1);
       break;
+    case CPTK_IS_MEMBER_POINTER:
+      inform (loc, "  %qT is not a member pointer", t1);
+      break;
     case CPTK_IS_NOTHROW_ASSIGNABLE:
       inform (loc, "  %qT is not nothrow assignable from %qT", t1, t2);
       break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 9d848f6..e17f5ea 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -71,6 +71,7 @@ DEFTRAIT_EXPR (IS_ENUM, "__is_enum", 1)
 DEFTRAIT_EXPR (IS_FINAL, "__is_final", 1)
 DEFTRAIT_EXPR (IS_LAYOUT_COMPATIBLE, "__is_layout_compatible", 2)
 DEFTRAIT_EXPR (IS_LITERAL_TYPE, "__is_literal_type", 1)
+DEFTRAIT_EXPR (IS_MEMBER_POINTER, "__is_member_pointer", 1)
 DEFTRAIT_EXPR (IS_NOTHROW_ASSIGNABLE, "__is_nothrow_assignable", 2)
 DEFTRAIT_EXPR (IS_NOTHROW_CONSTRUCTIBLE, "__is_nothrow_constructible", -1)
 DEFTRAIT_EXPR (IS_NOTHROW_CONVERTIBLE, "__is_nothrow_convertible", 2)
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 2bb5455..a462ed3 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12425,6 +12425,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_LITERAL_TYPE:
       return literal_type_p (type1);
 
+    case CPTK_IS_MEMBER_POINTER:
+      return TYPE_PTRMEM_P (type1);
+
     case CPTK_IS_NOTHROW_ASSIGNABLE:
       return is_nothrow_xible (MODIFY_EXPR, type1, type2);
 
@@ -12627,6 +12630,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_BOUNDED_ARRAY:
     case CPTK_IS_CLASS:
     case CPTK_IS_ENUM:
+    case CPTK_IS_MEMBER_POINTER:
     case CPTK_IS_SAME:
     case CPTK_IS_SCOPED_ENUM:
     case CPTK_IS_UNION:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index 744cfb3..349fae7 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -92,6 +92,9 @@
 #if !__has_builtin (__is_literal_type)
 # error "__has_builtin (__is_literal_type) failed"
 #endif
+#if !__has_builtin (__is_member_pointer)
+# error "__has_builtin (__is_member_pointer) failed"
+#endif
 #if !__has_builtin (__is_nothrow_assignable)
 # error "__has_builtin (__is_nothrow_assignable) failed"
 #endif
diff --git a/gcc/testsuite/g++.dg/ext/is_member_pointer.C b/gcc/testsuite/g++.dg/ext/is_member_pointer.C
new file mode 100644
index 0000000..7ee2e3a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_member_pointer.C
@@ -0,0 +1,30 @@
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+
+#define SA_TEST_NON_VOLATILE(TRAIT, TYPE, EXPECT)	\
+  SA(TRAIT(TYPE) == EXPECT);						\
+  SA(TRAIT(const TYPE) == EXPECT)
+
+#define SA_TEST_CATEGORY(TRAIT, TYPE, EXPECT)	\
+  SA(TRAIT(TYPE) == EXPECT);					\
+  SA(TRAIT(const TYPE) == EXPECT);				\
+  SA(TRAIT(volatile TYPE) == EXPECT);			\
+  SA(TRAIT(const volatile TYPE) == EXPECT)
+
+SA_TEST_CATEGORY(__is_member_pointer, int (ClassType::*), true);
+SA_TEST_CATEGORY(__is_member_pointer, ClassType (ClassType::*), true);
+
+SA_TEST_NON_VOLATILE(__is_member_pointer, int (ClassType::*)(int), true);
+SA_TEST_NON_VOLATILE(__is_member_pointer, int (ClassType::*)(int) const, true);
+SA_TEST_NON_VOLATILE(__is_member_pointer, int (ClassType::*)(float, ...), true);
+SA_TEST_NON_VOLATILE(__is_member_pointer, ClassType (ClassType::*)(ClassType), true);
+SA_TEST_NON_VOLATILE(__is_member_pointer,
+        float (ClassType::*)(int, float, int[], int&), true);
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_member_pointer, ClassType, false);