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 <kmat...@cs.washington.edu>
---
gcc/cp/constraint.cc | 3 ++
gcc/cp/cp-trait.def | 1 +
gcc/cp/semantics.cc | 4 ++
gcc/testsuite/g++.dg/ext/has-builtin-1.C | 3 ++
gcc/testsuite/g++.dg/ext/is_function.C | 58 ++++++++++++++++++++++++
5 files changed, 69 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/ext/is_function.C
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index f6951ee2670..927605c6cb7 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3754,6 +3754,9 @@ diagnose_trait_expr (tree expr, tree args)
case CPTK_IS_UNION:
inform (loc, " %qT is not a union", t1);
break;
+ case CPTK_IS_FUNCTION:
+ inform (loc, " %qT is not a function", t1);
+ break;
case CPTK_IS_AGGREGATE:
inform (loc, " %qT is not an aggregate", t1);
break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 1e3310cd682..3cd3babc242 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -83,6 +83,7 @@ DEFTRAIT_EXPR (IS_TRIVIALLY_ASSIGNABLE,
"__is_trivially_assignable", 2)
DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE, "__is_trivially_constructible", -1)
DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
+DEFTRAIT_EXPR (IS_FUNCTION, "__is_function", 1)
DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY,
"__reference_constructs_from_temporary", 2)
DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY,
"__reference_converts_from_temporary", 2)
/* FIXME Added space to avoid direct usage in GCC 13. */
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 2f37bc353a1..b976633645a 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12072,6 +12072,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree
type2)
case CPTK_IS_ENUM:
return type_code1 == ENUMERAL_TYPE;
+ case CPTK_IS_FUNCTION:
+ return type_code1 == FUNCTION_TYPE;
+
case CPTK_IS_FINAL:
return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1);
@@ -12293,6 +12296,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind,
tree type1, tree type2)
case CPTK_IS_UNION:
case CPTK_IS_SAME:
case CPTK_IS_REFERENCE:
+ case CPTK_IS_FUNCTION:
break;
case CPTK_IS_LAYOUT_COMPATIBLE:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index b697673790c..90eb00ebf2d 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -149,3 +149,6 @@
#if !__has_builtin (__is_reference)
# error "__has_builtin (__is_reference) failed"
#endif
+#if !__has_builtin (__is_function)
+# error "__has_builtin (__is_function) 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
index 00000000000..2e1594b12ad
--- /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);
--
2.41.0
