Hi, I'm trying to write a spatch rule that has some inversion logic for a given struct member, but I'm struggling to express this in SmPL. I'm also a bit of a coccinelle novice, however. Specifically, I'm trying to express:
For all structs, for each member `M` of type `struct rwlock`, if there are calls to `rwlock_wlock(&M)` and `rwlock_wunlock(&M)`, but there are no calls to `rwlock_rlock(&M)` or `rwlock_runlock(&M)`, then change `M`'s type from `struct rwlock` to `struct lock` and change calls to `rwlock_wlock(&M)` and `rwlock_wunlock(&M)` to `lock_lock(&M)` and `lock_unlock(&M)`, respectively. In other words, "if I'm not using the reader part of an rwlock, make it into a normal boring lock." I realize that tracking whether, in a call to f(&something->M), something is actually of the type in which rwlock was replaced is kind of hard (I think?). But I'd be willing to compromise on just assuming that something->M is always correct, because M always has unique-enough names. Or maybe that compromise isn't needed due to some sort of amazing coccinelle type inference, but anyway, I'm willing to compromise. The trickiest part seems to be, however, only doing this in the case where there aren't calls to `rwlock_rlock(&M)` and `rwlock_runlock(&M)`. I tried using a virtual rule and a depends clause, but those dependencies don't seem to work over a given instance of an identifier. I could probably hack my way toward that with a ridiculous sed expression, or do it procedurally after parsing the AST. But it seems like this would be a good case for where Coccinelle makes things easier, so I thought I'd commit to getting it done with spatch. Any pointers would be appreciated. Thanks, Jason _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
