This patch implements built-in trait for std::is_invocable.
gcc/cp/ChangeLog:
* cp-trait.def: Define __is_invocable.
* constraint.cc (diagnose_trait_expr): Handle CPTK_IS_INVOCABLE.
* semantics.cc (trait_expr_value): Likewise.
(finish_trait_expr): Likewise.
* cp-tree.h (build_invoke): New function.
* method.cc (build_invoke): New function.
gcc/testsuite/ChangeLog:
* g++.dg/ext/has-builtin-1.C: Test existence of __is_invocable.
* g++.dg/ext/is_invocable1.C: New test.
* g++.dg/ext/is_invocable2.C: New test.
* g++.dg/ext/is_invocable3.C: New test.
* g++.dg/ext/is_invocable4.C: New test.
Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
---
gcc/cp/constraint.cc | 6 +
gcc/cp/cp-trait.def | 1 +
gcc/cp/cp-tree.h | 2 +
gcc/cp/method.cc | 134 +++++++++
gcc/cp/semantics.cc | 5 +
gcc/testsuite/g++.dg/ext/has-builtin-1.C | 3 +
gcc/testsuite/g++.dg/ext/is_invocable1.C | 349 +++++++++++++++++++++++
gcc/testsuite/g++.dg/ext/is_invocable2.C | 139 +++++++++
gcc/testsuite/g++.dg/ext/is_invocable3.C | 51 ++++
gcc/testsuite/g++.dg/ext/is_invocable4.C | 33 +++
10 files changed, 723 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/ext/is_invocable1.C
create mode 100644 gcc/testsuite/g++.dg/ext/is_invocable2.C
create mode 100644 gcc/testsuite/g++.dg/ext/is_invocable3.C
create mode 100644 gcc/testsuite/g++.dg/ext/is_invocable4.C
diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index c28d7bf428e..6d14ef7dcc7 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3792,6 +3792,12 @@ diagnose_trait_expr (tree expr, tree args)
case CPTK_IS_FUNCTION:
inform (loc, " %qT is not a function", t1);
break;
+ case CPTK_IS_INVOCABLE:
+ if (!t2)
+ inform (loc, " %qT is not invocable", t1);
+ else
+ inform (loc, " %qT is not invocable by %qE", t1, t2);
+ 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 b1c875a6e7d..4e420d5390a 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -75,6 +75,7 @@ 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_INVOCABLE, "__is_invocable", -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/cp-tree.h b/gcc/cp/cp-tree.h
index 1938ada0268..83dc20e1130 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7338,6 +7338,8 @@ extern tree get_copy_assign (tree);
extern tree get_default_ctor (tree);
extern tree get_dtor (tree, tsubst_flags_t);
extern tree build_stub_object (tree);
+extern tree build_invoke (tree, const_tree,
+ tsubst_flags_t);
extern tree strip_inheriting_ctors (tree);
extern tree inherited_ctor_binfo (tree);
extern bool base_ctor_omit_inherited_parms (tree);
diff --git a/gcc/cp/method.cc b/gcc/cp/method.cc
index 08a3d34fb01..faf932258e6 100644
--- a/gcc/cp/method.cc
+++ b/gcc/cp/method.cc
@@ -1928,6 +1928,140 @@ build_trait_object (tree type)
return build_stub_object (type);
}
+/* [func.require] Build an expression of INVOKE(FN_TYPE, ARG_TYPES...). If the
+ given is not invocable, returns error_mark_node. */
+
+tree
+build_invoke (tree fn_type, const_tree arg_types, tsubst_flags_t complain)
+{
+ if (error_operand_p (fn_type) || error_operand_p (arg_types))
+ return error_mark_node;
+
+ gcc_assert (TYPE_P (fn_type));
+ gcc_assert (TREE_CODE (arg_types) == TREE_VEC);
+
+ /* Access check is required to determine if the given is invocable. */
+ deferring_access_check_sentinel acs (dk_no_deferred);
+
+ /* INVOKE is an unevaluated context. */
+ cp_unevaluated cp_uneval_guard;
+
+ bool is_ptrdatamem;
+ bool is_ptrmemfunc;
+ if (TREE_CODE (fn_type) == REFERENCE_TYPE)
+ {
+ tree deref_fn_type = TREE_TYPE (fn_type);
+ is_ptrdatamem = TYPE_PTRDATAMEM_P (deref_fn_type);
+ is_ptrmemfunc = TYPE_PTRMEMFUNC_P (deref_fn_type);
+
+ /* Dereference fn_type if it is a pointer to member. */
+ if (is_ptrdatamem || is_ptrmemfunc)
+ fn_type = deref_fn_type;
+ }
+ else
+ {
+ is_ptrdatamem = TYPE_PTRDATAMEM_P (fn_type);
+ is_ptrmemfunc = TYPE_PTRMEMFUNC_P (fn_type);
+ }
+
+ if (is_ptrdatamem && TREE_VEC_LENGTH (arg_types) != 1)
+ {
+ if (complain & tf_error)
+ error ("pointer to data member type %qT can only be invoked with "
+ "one argument", fn_type);
+ return error_mark_node;
+ }
+
+ if (is_ptrmemfunc && TREE_VEC_LENGTH (arg_types) == 0)
+ {
+ if (complain & tf_error)
+ error ("pointer to member function type %qT must be invoked with "
+ "at least one argument", fn_type);
+ return error_mark_node;
+ }
+
+ /* Construct an expression of a pointer to member. */
+ tree ptrmem_expr;
+ if (is_ptrdatamem || is_ptrmemfunc)
+ {
+ tree datum_type = TREE_VEC_ELT (arg_types, 0);
+
+ /* datum must be a class type or a reference/pointer to a class type. */
+ if (!(CLASS_TYPE_P (datum_type)
+ || ((TYPE_REF_P (datum_type) || POINTER_TYPE_P (datum_type))
+ && CLASS_TYPE_P (TREE_TYPE (datum_type)))))
+ {
+ if (complain & tf_error)
+ error ("first argument type %qT of a pointer to member must be"
+ "a class type or a reference/pointer to a class type",
+ datum_type);
+ return error_mark_node;
+ }
+
+ bool is_refwrap = false;
+ if (CLASS_TYPE_P (datum_type))
+ {
+ /* 1.2 & 1.5: Handle std::reference_wrapper. */
+ tree datum_decl = TYPE_NAME (TYPE_MAIN_VARIANT (datum_type));
+ if (decl_in_std_namespace_p (datum_decl))
+ {
+ const_tree name = DECL_NAME (datum_decl);
+ if (name && (id_equal (name, "reference_wrapper")))
+ {
+ /* Retrieve T from std::reference_wrapper<T>,
+ i.e., decltype(datum.get()). */
+ datum_type = TREE_VEC_ELT (TYPE_TI_ARGS (datum_type), 0);
+ is_refwrap = true;
+ }
+ }
+ }
+
+ tree ptrmem_class_type = TYPE_PTRMEM_CLASS_TYPE (fn_type);
+ const bool ptrmem_is_base_of_datum =
+ (NON_UNION_CLASS_TYPE_P (ptrmem_class_type)
+ && NON_UNION_CLASS_TYPE_P (datum_type)
