Define variable in modules

[Nick Gearls]

Hello,

It would sometimes be very handy to be able to define a variable (like -D on command-line or "Define xxx" in the config) inside a module.
This would, for instance, allow to have a config file based on a define from the module, knowing if the new syntax is known or not, etc.

Concrete example: in mod_security2, they introduced a new "collection".
If you use this collection in an old version, it's a syntax error.
If mod_security2 defines the variable "support_new_collection" (OK, very bad name obviously), then we can enclose the rule using a "<IfDefine support_new_collection>.

Would it be possible to export a function to define such a variable?

Thanks