在emacs程式設計中有以下需求
- 從呼叫一個函式的地方跳轉到函式的定義的地方
- 或是反過來從函式定義的地方列出所有呼叫這個函式的地方
實現辦法
需要安裝以下軟體
- gnu global（閱讀原始碼的工具）官網
- emacs的gtags外掛
- 啟動emacs後，輸入下面的命令，來啟動gtags的功能
M-x ggtags-modegnu global安裝
apt-get install globalemacs的gtags外掛安裝
M-x list-packages找到ggtags後，滑鼠點選，再點安裝
使用方法
1，在存放程式碼的根目錄執行：
$ gtags執行後，會發現在生成了3個檔案， GPATH GRTAGS GTAGS
2，啟動emacs
3，啟動emacs後，輸入下面的命令，來啟動gtags的功能
M-x ggtags-mode4，使用下面的函式就可以實現，檢視程式碼的各種需求了。
ggtags-find-tag-dwim
Find a tag by context.
If point is at a definition tag, find references, and vice versa.
If point is at a line that matches ``ggtags-include-pattern``, find
the include file instead.
To force finding a definition tag, call it with a prefix (``C-u``).
ggtags-find-tag-mouse
Like ``ggtags-find-tag-dwim`` but suitable for binding to mouse
events.
ggtags-find-definition
Find definition tags. With ``C-u`` ask for the tag name with
completion.
ggtags-find-reference
Find reference tags. With ``C-u`` ask for the tag name with completion.
ggtags-find-other-symbol
Find tags that have no definitions. With ``C-u`` ask for the tag
name with completion.
ggtags-find-tag-regexp
Find definition tags matching a regexp. By default it lists all
matching tags in the project. With ``C-u`` restrict the lists to a
directory of choice.
ggtags-idutils-query
Use idutils to find matches.
ggtags-grep
Grep for lines matching a regexp. This is usually the slowest.
ggtags-find-file
Find a file from all the files indexed by ``gtags``.
ggtags-query-replace
Do a query replace in all files found in a search.
Handling multiple matches
+++++++++++++++++++++++++
When a search finds multiple matches, a buffer named
``*ggtags-global*`` is popped up and ``ggtags-navigation-mode`` is
turned on to facilitate locating the right match.
``ggtags-navigation-mode`` makes a few commands in the
``*ggtags-global*`` buffer globally accessible:
``M-n``
Move to the next match.
``M-p``
Move to the previous match.
``M-}``
Move to next file.
``M-{``
Move to previous file.
``M-=``
Move to the file where navigation session starts.
``M-<``
Move to the first match.
``M->``
Move to the last match.
``C-M-s`` or ``M-s s``
Use ``isearch`` to find the match.
``RET``
Found the right match so exit navigation mode. Resumable by ``M-,``
(``tags-loop-continue``).
``M-*``
Abort and go back to the location where the search was started.
Miscellaneous commands
++++++++++++++++++++++
Commands are available from the ``Ggtags`` menu in ``ggtags-mode``.
ggtags-prev-mark
Move to the previously (older) visited location. Unlike ``M-*``
this doesn`t delete the location from the tag ring.
ggtags-next-mark
Move to the next (newer) visited location.
ggtags-view-tag-history
Pop to a buffer listing all visited locations from newest to
oldest. The buffer is a next error buffer and works with standard
commands ``next-error`` and ``previous-error``. In addition ``TAB``
and ``S-TAB`` move to next/prev entry, and ``RET`` visits the
location. ``M-n`` and ``M-p`` move to and display the next/previous
entry.
ggtags-view-search-history
View or re-run past searches as kept in
``ggtags-global-search-history``.
ggtags-kill-file-buffers
Kill all file-visiting buffers of current project.
ggtags-toggle-project-read-only
Toggle opening files in ``read-only`` mode. Handy if the main
purpose of source navigation is to read code.
ggtags-visit-project-root
Open the project root directory in ``dired``.
ggtags-delete-tags
Delete the GTAGS, GRTAGS, GPATH and ID files of current project.
ggtags-explain-tags
Explain how each file is indexed in current project.
ggtags-browse-file-as-hypertext
Use ``htags`` to generate HTML of the source tree. This allows
browsing the project in a browser with cross-references.使用舉例
1，從呼叫一個函式的地方跳轉到函式的定義的地方
M-x ggtags-find-definition
對應的快捷鍵：M-.2，從呼叫一個函式的地方跳轉到函式的定義的地方後，返回到呼叫函式的地方
M-x ggtags-prev-mark
對應的快捷鍵：M-,3，或是反過來從函式定義的地方列出所有呼叫這個函式的地方
M-x ggtags-find-reference
對應的快捷鍵：M-]4，檢視導航過的歷史記錄
M-x ggtags-view-tag-history
對應的快捷鍵：C-c M-h