c-lineup-argcont is a compiled Lisp function in `cc-align.el'.

(c-lineup-argcont ELEM)

Line up a continued argument.

foo (xyz, aaa + bbb + ccc
+ ddd + eee + fff); <- c-lineup-argcont

Only continuation lines like this are touched, nil is returned on lines
which are the start of an argument.

Within a gcc asm block, ":" is recognized as an argument separator,
but of course only between operand specifications, not in the expressions
for the operands.

Works with: arglist-cont, arglist-cont-nonempty.