Commit 151496a4 authored by Philipp Stephani's avatar Philipp Stephani

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--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.

* 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.
parent f04a527a
......@@ -190,6 +190,10 @@ calling 'eldoc-message' directly.
** Old-style backquotes now generate an error. They have been
generating warnings for a decade.
** Defining a Common Lisp structure using 'cl-defstruct' or
'cl-struct-define' whose name clashes with a builtin type (e.g.,
'integer' or 'hash-table') now signals an error.
* Lisp Changes in Emacs 27.1
......@@ -43,6 +43,7 @@
;;; Code:
(require 'cl-generic)
(require 'cl-lib)
(require 'macroexp)
;; `gv' is required here because cl-macs can be loaded before loaddefs.el.
......@@ -2663,6 +2664,9 @@ non-nil value, that slot cannot be set via `setf'.
(forms nil)
(docstring (if (stringp (car descs)) (pop descs)))
pred-form pred-check)
;; Can't use `cl-check-type' yet.
(unless (cl--struct-name-p name)
(signal 'wrong-type-argument (list 'cl-struct-name-p name 'name)))
(setq descs (cons '(cl-tag-slot)
(mapcar (function (lambda (x) (if (consp x) x (list x))))
......@@ -36,6 +36,7 @@
;;; Code:
(eval-when-compile (require 'cl-generic))
(eval-when-compile (require 'cl-lib))
(eval-when-compile (require 'cl-macs)) ;For cl--struct-class.
......@@ -50,6 +51,12 @@
(apply #'error string (append sargs args))
(signal 'cl-assertion-failed `(,form ,@sargs)))))
(defun cl--struct-name-p (name)
"Return t if NAME is a valid structure name for `cl-defstruct'."
(and name (symbolp name) (not (keywordp name))
(not (memq name (eval-when-compile cl--generic-all-builtin-types)))
;; When we load this (compiled) file during pre-loading, the cl--struct-class
;; code below will need to access the `cl-struct' info, since it's considered
;; already as its parent (because `cl-struct' was defined while the file was
......@@ -110,6 +117,7 @@
(defun cl-struct-define (name docstring parent type named slots children-sym
tag print)
(cl-check-type name cl--struct-name)
(unless type
;; Legacy defstruct, using tagged vectors. Enable backward compatibility.
(cl-old-struct-compat-mode 1))
......@@ -497,4 +497,13 @@ collection clause."
vconcat (vector (1+ x)))
[2 3 4 5 6])))
(ert-deftest cl-defstruct/builtin-type ()
(macroexpand '(cl-defstruct hash-table))
:type 'wrong-type-argument)
(macroexpand '(cl-defstruct (hash-table (:predicate hash-table-p))))
:type 'wrong-type-argument))
;;; cl-macs-tests.el ends here
;;; cl-preloaded-tests.el --- unit tests for cl-preloaded.el -*- lexical-binding: t; -*-
;; Copyright (C) 2017 Free Software Foundation, Inc.
;; Author: Philipp Stephani <>
;; This file is part of GNU Emacs.
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <>.
;;; Commentary:
;; Unit tests for lisp/emacs-lisp/cl-preloaded.el.
;;; Code:
(ert-deftest cl-struct-define/builtin-type ()
(cl-struct-define 'hash-table nil nil 'record nil nil
'cl-preloaded-tests-tag 'cl-preloaded-tests nil)
:type 'wrong-type-argument))
;;; cl-preloaded-tests.el ends here
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