The standard way to add support for macros and environment is writing a style file, it's documented here: https://www.gnu.org/software/auctex/manual/auctex.html#Style-Files The relevant functions are TeX-add-symbols
and LaTeX-add-environments
.
To add new macros and environments without creating style files see this answer: https://stackoverflow.com/a/17249399/2442087 For example, to add the foo
macro and the bar
environment add this to your init file:
(add-hook 'LaTeX-mode-hook
(lambda ()
(TeX-add-symbols "foo")
(LaTeX-add-environments "bar")))