We can define a bunch of bindings for gud-mode through
gud-mode-map. But it seems these bindings only hold when the active window is one of the dedicated gdb windows (or simply the comint window if you're not using many-windows).
I can't find any keymap that is active for the source code being debugged -- the only minor mode that seems to be active is gdb-many-windows-mode. That does not have a keymap however. So I tried redefining it:
(define-minor-mode gdb-many-windows "Redefine many windows to include a keymap" :global t :group 'gdb :version "22.1" :keymap my-customized-gdb-mode-map (if (and gud-comint-buffer (buffer-name gud-comint-buffer)) (ignore-errors (gdb-restore-windows))))
But then I realized this is an always-active global mode. So how would I go about customizing keybindngs that are active for the source buffer??