posix_spawn(3) support on OpenBSD

[nuudlman]

OpenBSD has supported posix_spawn(3) since version 5.2

It appears that support is already plumbed up for NetBSD, so I'll try to set up a pull request later today.

[nuudlman]

OpenBSD defines posix_spawnattr_t and posix_spawn_file_actions_t opaquely, so I'm not sure how to define those symbols.

Right now I have it set up as

pub type posix_spawnattr_t = *mut __posix_spawnattr;
pub type posix_spawn_file_actions_t = *mut __posix_spawn_file_actions;

but I can't get a definition for __posix_spawnattr and __posix_spawn_file_actions that will pass the either the compiler or the test suite.

If I define the types exactly as they actually are, the test suite fails because it tries to instantiate them directly. Defining an empty type (pub struct __posix_spawnattr {}) runs into the missing copy implementations lint.

Is there something obvious I'm missing here?

[semarie]

opaque type could be implemented using:

pub type posix_spawnattr_t = *mut ::c_void;
pub type posix_spawn_file_actions_t = *mut ::c_void;

it means there are "pointer on something".

this strategy is already used for pthread_attr_t for example (which is also opaque type on OpenBSD).

[nuudlman]

That worked! Thanks for the suggestion.

[nuudlman]

Implemented in #3502