Merge from origin/emacs-28

af01b674ce (origin/emacs-28) ; Fix spacing in previous commit
915e044d60 Use the correct label in the warning
6e83a4100a ; * admin/make-tarball.txt: Should configure --with-native...
525602d682 ; * etc/TODO (display): Add entry about Default_Ignorables.
65de510c16 ; Fix 'restore-buffer-modified-p' doc string typo
9d8202b45e Add Emacs 27 compatibility hack
89d64fca75 Pacify GCC 10.3 -Wmaybe-uninitialized
bb8ef1aa30 * lisp/tab-bar.el (tab-detach, tab-window-detach): New ali...
7ae70054aa ; * src/composite.h (LGSTRING_FONT): Add comment about its...
1af00e67d6 Include the refcards in the release tarball
3c29fb705c ; * src/Makefile.in (../native-lisp): Make the long recipe...

1 files changed, 14 insertions, 0 deletions

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index f4716fe9a64..0d51019f735 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -74,6 +74,20 @@
 (require 'ring)
 (require 'project)
 
+(eval-and-compile
+  (when (version< emacs-version "28")
+    ;; etags.el in Emacs 26 and 27 uses EIEIO, and its location type
+    ;; inherits from `xref-location'.
+    (require 'eieio)
+
+    ;; Suppressing byte-compilation warnings (in Emacs 28+) about
+    ;; `defclass' not being defined, which happens because the
+    ;; `require' statement above is not evaluated either.
+    ;; FIXME: Use `with-suppressed-warnings' when we stop supporting Emacs 26.
+    (with-no-warnings
+      (defclass xref-location () ()
+        :documentation "(Obsolete) location represents a position in a file or buffer."))))
+
 (defgroup xref nil "Cross-referencing commands."
   :version "25.1"
   :group 'tools)