初步使用emacs阅读源码，C++项目。
用citre+universal ctags
如果我在命令行下先生成好tags文件，citre的jump/peek功能都能正常工作的；
但是我用citre-update-this-tags-file却只能生成一个空的tags文件（只有几行元数据），如下图
不知道啥情况
补充： emacs版本：GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.30, cairo version 1.15.10) of 2020-09-20
citre配置用的centaur的配置：
(use-package citre
:diminish
:bind (("C-x c j" . citre-jump+)
("C-x c k" . citre-jump-back)
("C-x c p" . citre-peek)
("C-x c a" . citre-ace-peek)
("C-x c u" . citre-update-this-tags-file))
:init
(require 'citre-config)
(setq citre-auto-enable-citre-mode-modes '(prog-mode))
(defun citre-jump+ ()
"Jump to the definition of the symbol at point.
Fallback to `xref-find-definitions'."
(interactive)
(condition-case _
(citre-jump)
(error (call-interactively #'xref-find-definitions))))
:config
(with-no-warnings
(with-eval-after-load 'projectile
(setq citre-project-root-function #'projectile-project-root))
;; Integrate with `lsp-mode' and `eglot'
(define-advice xref--create-fetcher (:around (fn &rest args) fallback)
(let ((fetcher (apply fn args))
(citre-fetcher
(let ((xref-backend-functions '(citre-xref-backend t)))
(ignore xref-backend-functions)
(apply fn args))))
(lambda ()
(or (with-demoted-errors "%s, fallback to citre"
(funcall fetcher))
(funcall citre-fetcher)))))
(defun lsp-citre-capf-function ()
"A capf backend that tries lsp first, then Citre."
(let ((lsp-result (pcase centaur-lsp
('lsp-mode
(and (fboundp #'lsp-completion-at-point)
(lsp-completion-at-point)))
('eglot
(and (fboundp #'eglot-completion-at-point)
(eglot-completion-at-point))))))
(if (and lsp-result
(try-completion
(buffer-substring (nth 0 lsp-result)
(nth 1 lsp-result))
(nth 2 lsp-result)))
lsp-result
(citre-completion-at-point))))
(defun enable-lsp-citre-capf-backend ()
"Enable the lsp + Citre capf backend in current buffer."
(add-hook 'completion-at-point-functions #'lsp-citre-capf-function nil t))
(add-hook 'citre-mode-hook #'enable-lsp-citre-capf-backend))))
本来我是想清楚地指示「这一整块都要删掉」才加了中括号。我想想有没有更好的写法吧。