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use super::SelectionContext;
use super::{Obligation, ObligationCause};
use super::util;
use middle::subst;
use middle::subst::Subst;
use middle::ty::{mod, Ty};
use middle::infer::InferCtxt;
use std::rc::Rc;
use syntax::ast;
use syntax::codemap::DUMMY_SP;
use util::ppaux::Repr;
pub fn impl_can_satisfy(infcx: &InferCtxt,
impl1_def_id: ast::DefId,
impl2_def_id: ast::DefId)
-> bool
{
debug!("impl_can_satisfy(\
impl1_def_id={}, \
impl2_def_id={})",
impl1_def_id.repr(infcx.tcx),
impl2_def_id.repr(infcx.tcx));
let impl1_substs =
util::fresh_substs_for_impl(infcx, DUMMY_SP, impl1_def_id);
let impl1_trait_ref =
(*ty::impl_trait_ref(infcx.tcx, impl1_def_id).unwrap()).subst(infcx.tcx, &impl1_substs);
let param_env = ty::empty_parameter_environment();
let mut selcx = SelectionContext::intercrate(infcx, ¶m_env, infcx.tcx);
let obligation = Obligation::new(ObligationCause::dummy(),
ty::Binder(ty::TraitPredicate {
trait_ref: Rc::new(impl1_trait_ref),
}));
debug!("impl_can_satisfy(obligation={})", obligation.repr(infcx.tcx));
selcx.evaluate_impl(impl2_def_id, &obligation)
}
pub fn impl_is_local(tcx: &ty::ctxt,
impl_def_id: ast::DefId)
-> bool
{
debug!("impl_is_local({})", impl_def_id.repr(tcx));
let trait_ref = ty::impl_trait_ref(tcx, impl_def_id).unwrap();
debug!("trait_ref={}", trait_ref.repr(tcx));
if trait_ref.def_id.krate == ast::LOCAL_CRATE {
debug!("trait {} is local to current crate",
trait_ref.def_id.repr(tcx));
return true;
}
trait_ref.input_types().iter().any(|&t| ty_is_local(tcx, t))
}
pub fn ty_is_local<'tcx>(tcx: &ty::ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
debug!("ty_is_local({})", ty.repr(tcx));
match ty.sty {
ty::ty_bool |
ty::ty_char |
ty::ty_int(..) |
ty::ty_uint(..) |
ty::ty_float(..) |
ty::ty_str(..) => {
false
}
ty::ty_unboxed_closure(..) => {
tcx.sess.bug("ty_is_local applied to unboxed closure type")
}
ty::ty_bare_fn(..) |
ty::ty_closure(..) => {
false
}
ty::ty_uniq(t) => {
let krate = tcx.lang_items.owned_box().map(|d| d.krate);
krate == Some(ast::LOCAL_CRATE) || ty_is_local(tcx, t)
}
ty::ty_vec(t, _) |
ty::ty_ptr(ty::mt { ty: t, .. }) |
ty::ty_rptr(_, ty::mt { ty: t, .. }) => {
ty_is_local(tcx, t)
}
ty::ty_tup(ref ts) => {
ts.iter().any(|&t| ty_is_local(tcx, t))
}
ty::ty_enum(def_id, ref substs) |
ty::ty_struct(def_id, ref substs) => {
def_id.krate == ast::LOCAL_CRATE || {
let variances = ty::item_variances(tcx, def_id);
subst::ParamSpace::all().iter().any(|&space| {
substs.types.get_slice(space).iter().enumerate().any(
|(i, &t)| {
match *variances.types.get(space, i) {
ty::Bivariant => {
false
}
ty::Contravariant |
ty::Covariant |
ty::Invariant => {
ty_is_local(tcx, t)
}
}
})
})
}
}
ty::ty_trait(ref tt) => {
tt.principal_def_id().krate == ast::LOCAL_CRATE
}
ty::ty_param(..) => {
false
}
ty::ty_projection(..) => {
false
}
ty::ty_infer(..) |
ty::ty_open(..) |
ty::ty_err => {
tcx.sess.bug(
format!("ty_is_local invoked on unexpected type: {}",
ty.repr(tcx))[])
}
}
}