GCC allows for having command-line options passed by a file by @file syntax. Using this the file should be added as prerequisite (aka dependency) to the target.
I'm not finding any reference in CMake docs about argument files, suggesting it's not supported. Or perhaps just takes a little bit more plumbing, e.g. cat file|xargs? Or some way telling CMake explicitly that the file is a prerequisite? I mean "Prerequisite" according to GNU Make terminology. If file contents change I have to rebuild. AKA dependency.
Which is it? And how does it work?