You can use a source block with a self-defined major mode.
It is easy to define a customized major mode with helper functions like define-derived-mode.
Let us name your new major mode myorg-mode. Then the name of the function executed on C-c C-c is org-babel-execute:myorg.
It is called with two arguments. The first arg is the content of the source block as a ...
I'd use etags because it comes with Emacs and is what the default implementation of M-. targets.
Given a C project you can use etags *.c *.h to generate the TAGS file in that directory and select it when prompted by M-.. Some C projects already provide a Makefile target for that, for example you can run make tags in the Emacs sources to generate them for the ...
s is bound to a new function that was recently added, and indeed it appears to be non–functional. I took a look at the source code, and it does attempt to pull file and line number from the stack frame, but none of the stack frames have any file and line number information :)
It then tries to run hook functions, but the list of hook functions is empty. Those ...
Org mode uses the standard Emacs minibuffer completion mechanism for tags: whenever a tag is expected (e.g. at the C-c a m prompt), you can type TAB to get a completion list. You can click on a completion to choose it (or, without a mouse, switch to the completion buffer, navigate to the completion of interest and press RET); or you can narrow down the ...
That is the correct way to do it. Your only other approach is to use something like ivy or helm, which when you type C-c a m will offer you a list of tags that you can use completion on to narrow down.
I was able to generate the tags running gtags --gtagslabel=ctags from the root of the project, using a configuration from ubuntu (zcat /usr/share/doc/global/examples/gtags.conf.gz > ~/.globalrc).
This was suggested to me through the org-mode mailing list: replace ‘org-tag-persistent-alist’ instead of org-tag-alist in ~/.emacs. I tried it: autocomplete works for both the local and global tag lists.
KO, I think that C-c a m works only in Agenda files and the one I searched is not a dedicated agenda file. Anyway (org-match-sparse-tree) which should do the trick delivers more than I want i.e. every Headline no matter which tag it has. Puzzled.
You should use the new advice system `nadvice` instead of the old one.
xref-find-definitions prompts the user already in its `interactive-form`. So you need to run `open-tags-file` in the interactive-form of your advice for the case that xref-find-definitions is called interactively.
I use the interactive specification of xref-find-definitions of emacs 25.3....
You have a spelling mistake:
The word is spelled function
I'm not using these features so I don't know for sure, but I suspect that the problem will be solved if you fix that name.