Raise an error when detecting old-style backquotes.

They have been deprecated for a decade now.

* src/lread.c (Fload): Don't use record_unwind_protect to warn about
old-style backquotes any more.  They now generate a hard error.
(read1): Signal an error when detecting old-style backquotes.  Remove
unused label.
(syms_of_lread): Remove unused internal variable
'lread--old-style-backquotes'.
(load_error_old_style_backquotes): Rename from
'load_warn_oldstyle_backquotes'.  Signal an error.

* lisp/emacs-lisp/bytecomp.el (byte-compile-from-buffer): Remove check
from byte compiler.  It isn't triggered any more.

* test/src/lread-tests.el (lread-tests--old-style-backquotes): Adapt
unit test.

* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp-tests--old-style-backquotes)
(bytecomp-tests-function-put): Adapt unit tests.

* etc/NEWS: Document change.

1 files changed, 1 insertions, 7 deletions

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 590db570c56..45fa188d6c8 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -2048,14 +2048,8 @@ With argument ARG, insert value in current buffer after the form."
                  (not (eobp)))
           (setq byte-compile-read-position (point)
                 byte-compile-last-position byte-compile-read-position)
-          (let* ((lread--old-style-backquotes nil)
-                 (lread--unescaped-character-literals nil)
+          (let* ((lread--unescaped-character-literals nil)
                  (form (read inbuffer)))
-            ;; Warn about the use of old-style backquotes.
-            (when lread--old-style-backquotes
-              (byte-compile-warn "!! The file uses old-style backquotes !!
-This functionality has been obsolete for more than 10 years already
-and will be removed soon.  See (elisp)Backquote in the manual."))
             (when lread--unescaped-character-literals
               (byte-compile-warn
                "unescaped character literals %s detected!"