Prevent name clashes between CL structures and builtin types

* lisp/emacs-lisp/cl-preloaded.el (cl-struct-define): Don't allow
structures with the same names as builtin types.
(cl--typeof-types, cl--all-builtin-types): Move from cl-generic.el and
rename.
(cl--struct-name-p): New helper function.

* lisp/emacs-lisp/cl-macs.el (cl-defstruct): Don't allow structures
with the same names as builtin types.

* lisp/emacs-lisp/cl-generic.el (cl--generic-typeof-generalizer)
(cl-generic-generalizers): Adapt to name change.

* test/lisp/emacs-lisp/cl-macs-tests.el (cl-defstruct/builtin-type):
* test/lisp/emacs-lisp/cl-preloaded-tests.el
(cl-struct-define/builtin-type): New unit tests.

* etc/NEWS: Document changed behavior.

1 files changed, 9 insertions, 1 deletions

diff --git a/test/lisp/emacs-lisp/cl-macs-tests.el b/test/lisp/emacs-lisp/cl-macs-tests.el
index edb1530cad5..6e9fb44b4b0 100644
--- a/test/lisp/emacs-lisp/cl-macs-tests.el
+++ b/test/lisp/emacs-lisp/cl-macs-tests.el
@@ -497,7 +497,6 @@ collection clause."
                           vconcat (vector (1+ x)))
                  [2 3 4 5 6])))
 
-
 (ert-deftest cl-macs-loop-for-as-equals-and ()
   "Test for https://debbugs.gnu.org/29799 ."
   (let ((arr (make-vector 3 0)))
@@ -505,4 +504,13 @@ collection clause."
                    (cl-loop for k below 3 for x = k and z = (elt arr k)
                             collect (list k x))))))
 
+
+(ert-deftest cl-defstruct/builtin-type ()
+  (should-error
+   (macroexpand '(cl-defstruct hash-table))
+   :type 'wrong-type-argument)
+  (should-error
+   (macroexpand '(cl-defstruct (hash-table (:predicate hash-table-p))))
+   :type 'wrong-type-argument))
+
 ;;; cl-macs-tests.el ends here