flymake mode

How can I miss this wonderful feature until now?

Flymake is amazing. See the screenshot:


What you need is only a Makefile with an extra target "check-syntax":

check-syntax:
    gcc -o nul -Wall -Wextra -fsyntax-only $(CHK_SOURCES)

And of course type "M-x flymake-mode" when needed.

You can also customize the error and warning face in .emacs like:

(require 'flymake nil t)
(when (featurep 'flymake)
  (set-face-background 'flymake-errline "LightPink")
  (set-face-foreground 'flymake-errline "DarkRed")
  (set-face-bold-p 'flymake-errline t)
  (set-face-background 'flymake-warnline "LightBlue2")
  (set-face-foreground 'flymake-warnline "DarkBlue")
  (set-face-bold-p 'flymake-warnline t))