c++: Implement __is_function built-in trait

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

gcc/cp/ChangeLog:

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

gcc/testsuite/ChangeLog:

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

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

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index aa42017f67c5e19ab953377b2668942f6b09951b..4bea6089791141ca3b303505c2998f724541a1ee 100644 (file)
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3752,6 +3752,9 @@ diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_FINAL:
       inform (loc, "  %qT is not a final class", t1);
       break;
+    case CPTK_IS_FUNCTION:
+      inform (loc, "  %qT is not a function", t1);
+      break;
     case CPTK_IS_LAYOUT_COMPATIBLE:
       inform (loc, "  %qT is not layout compatible with %qT", t1, t2);
       break;

diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 2d82ed3dd3593f1d79f964b72bb2548b9e2d2949..89712f18667423a08800ee89c5eeb97017bd49b1 100644 (file)
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -69,6 +69,7 @@ DEFTRAIT_EXPR (IS_CONVERTIBLE, "__is_convertible", 2)
 DEFTRAIT_EXPR (IS_EMPTY, "__is_empty", 1)
 DEFTRAIT_EXPR (IS_ENUM, "__is_enum", 1)
 DEFTRAIT_EXPR (IS_FINAL, "__is_final", 1)
+DEFTRAIT_EXPR (IS_FUNCTION, "__is_function", 1)
 DEFTRAIT_EXPR (IS_LAYOUT_COMPATIBLE, "__is_layout_compatible", 2)
 DEFTRAIT_EXPR (IS_LITERAL_TYPE, "__is_literal_type", 1)
 DEFTRAIT_EXPR (IS_MEMBER_FUNCTION_POINTER, "__is_member_function_pointer", 1)

diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 4af5a60e16a40649dbccd91752930a64556005fb..4a95af477e715d2f2c0fb25ad50e4b9e7d9e3566 100644 (file)
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12419,6 +12419,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_FINAL:
       return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1);
 
+    case CPTK_IS_FUNCTION:
+      return type_code1 == FUNCTION_TYPE;
+
     case CPTK_IS_LAYOUT_COMPATIBLE:
       return layout_compatible_type_p (type1, type2);
 
@@ -12639,6 +12642,7 @@ 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_FUNCTION:
     case CPTK_IS_MEMBER_FUNCTION_POINTER:
     case CPTK_IS_MEMBER_OBJECT_POINTER:
     case CPTK_IS_MEMBER_POINTER:

diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index b667b5c33ac6d30f609db4e5aaaeb65a718a5e73..5215da27d6f639bd723eb6ad6fe332ea425b5d43 100644 (file)
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -86,6 +86,9 @@
 #if !__has_builtin (__is_final)
 # error "__has_builtin (__is_final) failed"
 #endif
+#if !__has_builtin (__is_function)
+# error "__has_builtin (__is_function) failed"
+#endif
 #if !__has_builtin (__is_layout_compatible)
 # error "__has_builtin (__is_layout_compatible) failed"
 #endif

diff --git a/gcc/testsuite/g++.dg/ext/is_function.C b/gcc/testsuite/g++.dg/ext/is_function.C
new file mode 100644 (file)
index 0000000..2e1594b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_function.C
@@ -0,0 +1,58 @@
+// { dg-do compile { target c++11 } }
+
+#include <testsuite_tr1.h>
+
+using namespace __gnu_test;
+
+#define SA(X) static_assert((X),#X)
+#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)
+
+struct A
+{ void fn(); };
+
+template<typename>
+struct AHolder { };
+
+template<class T, class U>
+struct AHolder<U T::*>
+{ using type = U; };
+
+// Positive tests.
+SA(__is_function(int (int)));
+SA(__is_function(ClassType (ClassType)));
+SA(__is_function(float (int, float, int[], int&)));
+SA(__is_function(int (int, ...)));
+SA(__is_function(bool (ClassType) const));
+SA(__is_function(AHolder<decltype(&A::fn)>::type));
+
+void fn();
+SA(__is_function(decltype(fn)));
+
+// Negative tests.
+SA_TEST_CATEGORY(__is_function, int, false);
+SA_TEST_CATEGORY(__is_function, int*, false);
+SA_TEST_CATEGORY(__is_function, int&, false);
+SA_TEST_CATEGORY(__is_function, void, false);
+SA_TEST_CATEGORY(__is_function, void*, false);
+SA_TEST_CATEGORY(__is_function, void**, false);
+SA_TEST_CATEGORY(__is_function, std::nullptr_t, false);
+
+SA_TEST_CATEGORY(__is_function, AbstractClass, false);
+SA(!__is_function(int(&)(int)));
+SA(!__is_function(int(*)(int)));
+
+SA_TEST_CATEGORY(__is_function, A, false);
+SA_TEST_CATEGORY(__is_function, decltype(&A::fn), false);
+
+struct FnCallOverload
+{ void operator()(); };
+SA_TEST_CATEGORY(__is_function, FnCallOverload, false);
+
+// Sanity check.
+SA_TEST_CATEGORY(__is_function, ClassType, false);
+SA_TEST_CATEGORY(__is_function, IncompleteClass, false);
+SA_TEST_CATEGORY(__is_function, IncompleteUnion, false);