> maybe_warning (OPT_Wfoo, frobbed, "foo is frobbed"); > > This tests whether Wfoo is enabled *before* it evaluates frobbed.
In the cases where such a check is warranted, "frobbed" is usually a fairly large collection of tests. It would be impractical (and ugly) to put such logic inside a macro call. There is a option_enabled() function which takes an OPT_* and returns nonzer if the option is enabled, in case you lose track of which OPT_* goes with which warn_* (or if the variable doesn't exist, or is other than a simple integer). But it's easier to use the warn_* variables for such cases.
