Demand is driven by calls to `AstConv::get_item_type_scheme` or
`AstConv::lookup_trait_def`.
-Currently, we "convert" types and traits in three phases (note that
+Currently, we "convert" types and traits in two phases (note that
conversion only affects the types of items / enum variants / methods;
it does not e.g. compute the types of individual expressions):
0. Intrinsics
-1. Trait definitions
-2. Type definitions
+1. Trait/Type definitions
Conversion itself is done by simply walking each of the items in turn
and invoking an appropriate function (e.g., `trait_def_of_item` or
- Because the type scheme includes defaults, cycles through type
parameter defaults are illegal even if those defaults are never
employed. This is not necessarily a bug.
-- The phasing of trait definitions before type definitions does not
- seem to be necessary, sufficient, or particularly helpful, given that
- processing a trait definition can trigger processing a type def and
- vice versa. However, if I remove it, I get ICEs, so some more work is
- needed in that area. -nmatsakis
*/
pub fn collect_item_types(tcx: &ty::ctxt) {
let ccx = &CrateCtxt { tcx: tcx, stack: RefCell::new(Vec::new()) };
- let mut visitor = CollectTraitDefVisitor{ ccx: ccx };
- ccx.tcx.map.krate().visit_all_items(&mut visitor);
-
let mut visitor = CollectItemTypesVisitor{ ccx: ccx };
ccx.tcx.map.krate().visit_all_items(&mut visitor);
}
}
///////////////////////////////////////////////////////////////////////////
-// First phase: just collect *trait definitions* -- basically, the set
-// of type parameters and supertraits. This is information we need to
-// know later when parsing field defs.
-
-struct CollectTraitDefVisitor<'a, 'tcx: 'a> {
- ccx: &'a CrateCtxt<'a, 'tcx>
-}
-
-impl<'a, 'tcx, 'v> intravisit::Visitor<'v> for CollectTraitDefVisitor<'a, 'tcx> {
- fn visit_item(&mut self, i: &hir::Item) {
- match i.node {
- hir::ItemTrait(..) => {
- // computing the trait def also fills in the table
- let _ = trait_def_of_item(self.ccx, i);
- }
- _ => { }
- }
- }
-}
-
-///////////////////////////////////////////////////////////////////////////
-// Second phase: collection proper.
struct CollectItemTypesVisitor<'a, 'tcx: 'a> {
ccx: &'a CrateCtxt<'a, 'tcx>
substs: substs,
};
- let trait_def = ty::TraitDef {
- paren_sugar: paren_sugar,
- unsafety: unsafety,
- generics: ty_generics,
- trait_ref: trait_ref,
- associated_type_names: associated_type_names,
- nonblanket_impls: RefCell::new(FnvHashMap()),
- blanket_impls: RefCell::new(vec![]),
- flags: Cell::new(ty::TraitFlags::NO_TRAIT_FLAGS)
- };
+ let trait_def = ty::TraitDef::new(unsafety,
+ paren_sugar,
+ ty_generics,
+ trait_ref,
+ associated_type_names);
return tcx.intern_trait_def(trait_def);