parser, completion, format

[dzhwinter]

Thanks for this awesome tool first.
i'm looking for the completion tool who can complete the inherit associate between class.
I have install company-mode ,irony-mode chenbin's cpputil-cmake. But it seems mess in my configuration.
my setup for irony-mode and company-irony-mode as your README:
(add-hook 'c++-mode-hook 'irony-mode)
(add-hook 'c-mode-hook 'irony-mode)
(defun my-irony-mode-hook ()
(define-key irony-mode-map [remap completion-at-point]
'irony-completion-at-point-async)
(define-key irony-mode-map [remap complete-symbol]
'irony-completion-at-point-async))
(add-hook 'irony-mode-hook 'my-irony-mode-hook)
(add-hook 'irony-mode-hook 'irony-cdb-autosetup-compile-options)

then i install irony-server in my emacs.
set my company-backends with company-irony

Here is my three question;

1. company-irony sometimes conflict with company-c-headers?
   in my config,
   ;; use for irony mode
   (add-to-list 'company-backends 'company-irony)
   (add-to-list 'company-backends 'company-c-headers)
   only this order works well.
2. irony-mode set the tab and indentation for all modes? how to change it?
3. add third party completion arguments with 'company-clang-arguments' ?
   I set it in my .dir-local.el, but no magic happen.

How to fix it?
thanks advance

[Sarcasm]

i'm looking for the completion tool who can complete the inherit associate between class.

What does it mean?

To answer your questions:

1. I already hear about this conflict, looking for company-c-headers in issues should give you an explanation. See company-irony obstructs other company backends #7 (comment)
2. Irony doesn't set tab and indentation, something else is modifying it.
3. Irony mode uses a compilation database for the compile options, look up the README. You could create a simple compilation database that returns the compile option from a .dir-locals.el, but I doubt that's you want.