(primitive-function): New type

The type hierarchy and `cl-type-of` code assumed that `subr-primitive`
only applies to functions, but since it also accepts special-forms it makes
it an unsuitable choice since it can't be a subtype of `compiled-function`.
So, use a new type `primitive-function` instead.

* lisp/subr.el (subr-primitive-p): Fix docstring (bug#69832).
(primitive-function-p): New function.

* lisp/emacs-lisp/cl-preloaded.el (primitive-function): Rename
from `subr-primitive` since `subr-primitive-p` means something else.

* src/data.c (Fcl_type_of): Return `primitive-function` instead
of `subr-primitive` for C functions.
(syms_of_data): Adjust accordingly.

* test/src/data-tests.el (data-tests--cl-type-of): Remove workaround.

1 files changed, 10 insertions, 1 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 38a3f6edb34..3de4412637f 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -312,11 +312,20 @@ value of last one, or nil if there are none."
                               cond '(empty-body unless) t)))
 
 (defsubst subr-primitive-p (object)
-  "Return t if OBJECT is a built-in primitive function."
+  "Return t if OBJECT is a built-in primitive written in C.
+Such objects can be functions or special forms."
   (declare (side-effect-free error-free))
   (and (subrp object)
        (not (subr-native-elisp-p object))))
 
+(defsubst primitive-function-p (object)
+  "Return t if OBJECT is a built-in primitive function.
+This excludes special forms, since they are not functions."
+  (declare (side-effect-free error-free))
+  (and (subrp object)
+       (not (or (subr-native-elisp-p object)
+                (eq (cdr (subr-arity object)) 'unevalled)))))
+
 (defsubst xor (cond1 cond2)
   "Return the boolean exclusive-or of COND1 and COND2.
 If only one of the arguments is non-nil, return it; otherwise