TeX-command and flymake

[Rahguzar]

Hi all,

I wanted to get errors and warnings produced during compilation of LaTeX
documents using flymake which is the interface I am used to getting such
information from. With TeX-parse-all-errors non-nil, it is
straightforward to implement a flymake backend,

(defun latex-refs--make-flymake-diagonostic (item)
  "Turn an error or warning ITEM from `TeX-error-list' to a flymake diagnostic."
  (goto-char (point-min))
  (when (and (not (nth 10 item)) (search-forward (nth 6 item) nil t))
    (flymake-make-diagnostic (current-buffer)
                             (match-beginning 0) (match-end 0)
                             (if (eq (nth 0 item) 'error) :error :warning)
                             (nth 3 item))))

;;;###autoload
(defun latex-refs-flymake-diagnostic-fun (report-fun &rest _args)
  "A flymake diagnostic function based on `TeX-error-list'.
See `flymake-diagnostic-functions' for REPORT-FUN."
(when-let ((buf (TeX-active-buffer)))
    (funcall report-fun
             (save-excursion
               (let ((diagnostics))
                 (dolist (item (buffer-local-value 'TeX-error-list buf))
                   (push (latex-refs--make-flymake-diagonostic item)
                         diagnostics))
                 (nreverse diagnostics))))))

The prefix `latex-refs` is nonsensical but I couldn't think of a better
name and just threw the functions in a package I had.

The function `latex-refs-flymake-diagnostic-fun` can then be added to
`flymake-diagonostic-functions`. There is also a canonical time to run
it which is when the compilation finishes. However it seems there is no
hook that I can use to issue a `flymake-start` command at such time.
`TeX-after-compilation-finished-functions` are only run if the
compilation finished successfully. So instead I had to advise the
sentinel. Is there a more canonical way to run something when
compilation is unsuccessful?

I also ended up writing another flymake backend which parse the BibTeX
log files and feeds the errors to flymake. I am not sure how robust the
parsing is and I need it to extend it to parse warnings too but the
current state can be found at
https://codeberg.org/rahguzar/latex-refs/src/commit/14c669f5d1c64760d089dd3418adcdbb31ee34c7/latex-refs.el#L174-L272

Now my questions are:

1) Is there a simpler way of getting LaTeX and BibTeX errors and
warnings through flymake?

2) Flymake integrates with `project.el` so to get warnings for both tex
and bib files together I also had to write a little project backend. Is
there another possibly simpler way?

3) It took some configuration but I quite like the resulting setup. Are
there parts of it that other people think are useful and that I can
contribute to auctex proper?

Thanks,
Rahguzar