Variable: gud-highlight-current-line
gud-highlight-current-line is a customizable variable defined in
gud.el.gz.
Value
nil
Documentation
Whether Gud should highlight the source line being debugged.
If non-nil, Gud will accentuate the source code line previously
executed upon each pause in the debugee's execution with an
overlay in the face gud-highlight-current-line-face.
If nil, yet one of hl-line-mode(var)/hl-line-mode(fun) or global-hl-line-mode(var)/global-hl-line-mode(fun) (which
see) is enabled, then the emphasis imposed by either of those
major modes is instead momentarily moved to the aforesaid source
line, until it is displaced by subsequent cursor motion.
This variable was added, or its default value changed, in Emacs 30.1.
Probably introduced at or before Emacs version 30.1.
Source Code
;; Defined in /usr/src/emacs/lisp/progmodes/gud.el.gz
;; Make sure the file named TRUE-FILE is in a buffer that appears on the screen
;; and that its line LINE is visible.
;; Put the overlay-arrow on the line LINE in that buffer.
;; Most of the trickiness in here comes from wanting to preserve the current
;; region-restriction if that's possible. We use an explicit display-buffer
;; to get around the fact that this is called inside a save-excursion.
(defcustom gud-highlight-current-line nil
"Whether Gud should highlight the source line being debugged.
If non-nil, Gud will accentuate the source code line previously
executed upon each pause in the debugee's execution with an
overlay in the face `gud-highlight-current-line-face'.
If nil, yet one of `hl-line-mode' or `global-hl-line-mode' (which
see) is enabled, then the emphasis imposed by either of those
major modes is instead momentarily moved to the aforesaid source
line, until it is displaced by subsequent cursor motion."
:version "30.1"
:type 'boolean)