c++: Implement __is_bounded_array built-in trait

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

gcc/cp/ChangeLog:

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

gcc/testsuite/ChangeLog:

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

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

gcc/cp/constraint.cc

@@ -3736,6 +3736,9 @@ diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_BASE_OF:
       inform (loc, "  %qT is not a base of %qT", t1, t2);
       break;
+    case CPTK_IS_BOUNDED_ARRAY:
+      inform (loc, "  %qT is not a bounded array", t1);
+      break;
     case CPTK_IS_CLASS:
       inform (loc, "  %qT is not a class", t1);
       break;

gcc/cp/cp-trait.def

@@ -62,6 +62,7 @@ DEFTRAIT_EXPR (IS_AGGREGATE, "__is_aggregate", 1)
 DEFTRAIT_EXPR (IS_ARRAY, "__is_array", 1)
 DEFTRAIT_EXPR (IS_ASSIGNABLE, "__is_assignable", 2)
 DEFTRAIT_EXPR (IS_BASE_OF, "__is_base_of", 2)
+DEFTRAIT_EXPR (IS_BOUNDED_ARRAY, "__is_bounded_array", 1)
 DEFTRAIT_EXPR (IS_CLASS, "__is_class", 1)
 DEFTRAIT_EXPR (IS_CONST, "__is_const", 1)
 DEFTRAIT_EXPR (IS_CONSTRUCTIBLE, "__is_constructible", -1)

gcc/cp/semantics.cc

@@ -12019,6 +12019,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
 	      && (same_type_ignoring_top_level_qualifiers_p (type1, type2)
 		  || DERIVED_FROM_P (type1, type2)));
 
+    case CPTK_IS_BOUNDED_ARRAY:
+      return type_code1 == ARRAY_TYPE && TYPE_DOMAIN (type1);
+
     case CPTK_IS_CLASS:
       return NON_UNION_CLASS_TYPE_P (type1);
 
@@ -12248,6 +12251,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
       break;
 
     case CPTK_IS_ARRAY:
+    case CPTK_IS_BOUNDED_ARRAY:
     case CPTK_IS_CLASS:
     case CPTK_IS_CONST:
     case CPTK_IS_ENUM:

gcc/testsuite/g++.dg/ext/has-builtin-1.C

@@ -65,6 +65,9 @@
 #if !__has_builtin (__is_base_of)
 # error "__has_builtin (__is_base_of) failed"
 #endif
+#if !__has_builtin (__is_bounded_array)
+# error "__has_builtin (__is_bounded_array) failed"
+#endif
 #if !__has_builtin (__is_class)
 # error "__has_builtin (__is_class) failed"
 #endif

gcc/testsuite/g++.dg/ext/is_bounded_array.C

@@ -0,0 +1,38 @@
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+
+#define SA_TEST_CONST(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_bounded_array, int[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, int[], false);
+SA_TEST_CATEGORY(__is_bounded_array, int[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, int[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, float*[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, float*[], false);
+SA_TEST_CATEGORY(__is_bounded_array, float*[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, float*[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[2], true);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[], false);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[2][3], true);
+SA_TEST_CATEGORY(__is_bounded_array, ClassType[][3], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(*)[2], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(*)[], false);
+SA_TEST_CATEGORY(__is_bounded_array, int(&)[2], false);
+SA_TEST_CONST(__is_bounded_array, int(&)[], false);
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_bounded_array, ClassType, false);
+SA_TEST_CONST(__is_bounded_array, void(), false);