From 22a7522ef3f0f3c13618214e61f60cb01d80eef4 Mon Sep 17 00:00:00 2001
From: Justin Davis <jrcd83@gmail.com>
Date: Tue, 26 Oct 2021 13:28:16 -0400
Subject: [PATCH] Fix emacs erlang-mode: xref switched to CL-Lib
Fix for GitHub issue #5314.
Xref is a package which is also bundled with emacs:
http://elpa.gnu.org/packages/xref.html
Xref switched its own internally defined classes from EIEIO to
CL-lib (emacs-mirror/emacs@86da812afb2572c7fead2bb07570b976bffd7c55).
erlang-mode subclasses xref-file-location in order to add a function
arity slot to xrefs.
If xref-file-location is a class, use defclass to subclass it. Otherwise
use cl-defstruct. Avoids referencing make-instance, slot-value functions
from EIEIO. Only references constructor, accessor, and predicate
functions. Updates comments that make references to classes.
Testing:
- cd into lib/tools/emacs.
- Run the tests included with erlang-mode from the shell:
emacs -Q -batch -L . -l erlang.el -l erlang-test.el \
-f ert-run-tests-batch-and-exit
- Copy xref.el from the xref package (>=1.3.1) into the
lib/tools/emacs directory.
- Run the tests again. This will load xref.el automatically
and use the new interface.
---
lib/tools/emacs/erlang.el | 48 +++++++++++++++++++++++++--------------
1 file changed, 31 insertions(+), 17 deletions(-)
diff --git a/lib/tools/emacs/erlang.el b/lib/tools/emacs/erlang.el
index 69a5fdaeb556..40fe32689e77 100644
--- a/lib/tools/emacs/erlang.el
+++ b/lib/tools/emacs/erlang.el
@@ -5120,8 +5120,8 @@ about Erlang modules."
;;
;; As mentioned this xref implementation is based on the etags xref
;; implementation. But in the cases where arity is considered the
-;; etags information structures (class xref-etags-location) will be
-;; translated to our own structures which include arity (class
+;; etags information structures (struct xref-etags-location) will be
+;; translated to our own structures which include arity (struct
;; erlang-xref-location). This translation is started in the function
;; `erlang-refine-xrefs'.
@@ -5129,6 +5129,11 @@ about Erlang modules."
;; with xref items with xref-etags-location and some deal with xref
;; items with erlang-xref-location.
+;; NOTE: Around Sept 2021, the xrefs package changed all of its defined types
+;; (i.e. xref-location, xref-file-location) from EIEIO classes to CL-Lib
+;; structures. These are both supported. Older Emacsen with earlier versions of
+;; xref will continue to use defclass. Newer Emacsen will use cl-defstruct.
+
(defun erlang-etags--xref-backend () 'erlang-etags)
(defun erlang-soft-require (feature)
@@ -5137,6 +5142,7 @@ about Erlang modules."
(when (and (erlang-soft-require 'xref)
(erlang-soft-require 'cl-generic)
+ (erlang-soft-require 'cl-lib)
(erlang-soft-require 'eieio)
(erlang-soft-require 'etags))
;; The purpose of using eval here is to avoid compilation
@@ -5165,10 +5171,20 @@ about Erlang modules."
(let ((erlang-replace-etags-tags-completion-table t))
(tags-completion-table)))
- (defclass erlang-xref-location (xref-file-location)
- ((arity :type fixnum :initarg :arity
- :reader erlang-xref-location-arity))
- :documentation "An erlang location is a file location plus arity.")
+ ;; Xref 1.3.1 bundled with Emacs 28+ switched from using EIEIO classes to
+ ;; using CL-Lib structs.
+ (if (find-class 'xref-file-location)
+ (progn
+ (defclass erlang-xref-location (xref-file-location)
+ ((arity :type fixnum :initarg :arity
+ :reader erlang-xref-location-arity))
+ :documentation "An erlang location is a file location plus arity.")
+ ;; Make a constructor with the same name that a CL structure would have.
+ (defalias 'make-erlang-xref-location 'erlang-xref-location))
+ (cl-defstruct (erlang-xref-location
+ (:include xref-file-location))
+ "An erlang location is a file location plus arity."
+ (arity 0 :type fixnum)))
;; This method definition only calls the superclass which is
;; the default behaviour if it was not defined. It is only
@@ -5331,8 +5347,7 @@ is non-nil then TAG is a regexp."
xrefs
(when (and xrefs
(fboundp 'xref-item-location)
- (fboundp 'xref-location-group)
- (fboundp 'slot-value))
+ (fboundp 'xref-location-group))
(let (files)
(cl-loop for xref in xrefs
for loc = (xref-item-location xref)
@@ -5357,7 +5372,8 @@ is non-nil then TAG is a regexp."
t))))
(defun erlang-xrefs-in-file (file kind tag is-regexp)
- (when (fboundp 'make-instance)
+ (when (and (fboundp 'make-erlang-xref-location)
+ (fboundp 'xref-make))
(with-current-buffer (find-file-noselect file)
(save-excursion
(goto-char (point-min))
@@ -5369,17 +5385,15 @@ is non-nil then TAG is a regexp."
for name = (match-string-no-properties 1)
for arity = (save-excursion
(erlang-get-arity))
- for loc = (make-instance 'erlang-xref-location
- :file file
- :line (line-number-at-pos)
- :column 0
- :arity arity)
+ for loc = (make-erlang-xref-location
+ :file file
+ :line (line-number-at-pos)
+ :column 0
+ :arity arity)
for sum = (erlang-xref-summary kind name arity)
when (and arity
(not (eq arity last-arity)))
- collect (make-instance 'xref-item
- :summary sum
- :location loc)
+ collect (xref-make sum loc)
do (setq last-arity arity)))))))
(defun erlang-xref-summary (kind tag arity)