1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 * Conversion from AST representation of types to the ty.rs
13 * representation. The main routine here is `ast_ty_to_ty()`: each use
14 * is parameterized by an instance of `AstConv` and a `RegionScope`.
16 * The parameterization of `ast_ty_to_ty()` is because it behaves
17 * somewhat differently during the collect and check phases,
18 * particularly with respect to looking up the types of top-level
19 * items. In the collect phase, the crate context is used as the
20 * `AstConv` instance; in this phase, the `get_item_ty()` function
21 * triggers a recursive call to `ty_of_item()` (note that
22 * `ast_ty_to_ty()` will detect recursive types and report an error).
23 * In the check phase, when the FnCtxt is used as the `AstConv`,
24 * `get_item_ty()` just looks up the item type in `tcx.tcache`.
26 * The `RegionScope` trait controls what happens when the user does
27 * not specify a region in some location where a region is required
28 * (e.g., if the user writes `&Foo` as a type rather than `&'a Foo`).
29 * See the `rscope` module for more details.
31 * Unlike the `AstConv` trait, the region scope can change as we descend
32 * the type. This is to accommodate the fact that (a) fn types are binding
33 * scopes and (b) the default region may change. To understand case (a),
34 * consider something like:
36 * type foo = { x: &a.int, y: |&a.int| }
38 * The type of `x` is an error because there is no region `a` in scope.
39 * In the type of `y`, however, region `a` is considered a bound region
40 * as it does not already appear in scope.
42 * Case (b) says that if you have a type:
44 * type bar = fn(&foo, &a.foo)
45 * The fully expanded version of type bar is:
46 * type bar = fn(&'foo &, &a.foo<'a>)
47 * Note that the self region for the `foo` defaulted to `&` in the first
48 * case but `&a` in the second. Basically, defaults that appear inside
49 * an rptr (`&r.T`) use the region `r` that appears in the rptr.
52 use middle::const_eval;
54 use middle::lang_items::FnMutTraitLangItem;
55 use rl = middle::resolve_lifetime;
56 use middle::subst::{Subst, Substs};
58 use middle::ty::ty_param_substs_and_ty;
60 use middle::typeck::lookup_def_tcx;
61 use middle::typeck::rscope::RegionScope;
62 use middle::typeck::rscope;
63 use util::ppaux::Repr;
67 use syntax::{ast, ast_util};
68 use syntax::codemap::Span;
69 use syntax::owned_slice::OwnedSlice;
70 use syntax::print::pprust::{lifetime_to_str, path_to_str};
73 fn tcx<'a>(&'a self) -> &'a ty::ctxt;
74 fn get_item_ty(&self, id: ast::DefId) -> ty::ty_param_bounds_and_ty;
75 fn get_trait_def(&self, id: ast::DefId) -> Rc<ty::TraitDef>;
77 // what type should we use when a type is omitted?
78 fn ty_infer(&self, span: Span) -> ty::t;
81 pub fn ast_region_to_region(tcx: &ty::ctxt, lifetime: &ast::Lifetime)
83 let r = match tcx.named_region_map.find(&lifetime.id) {
85 // should have been recorded by the `resolve_lifetime` pass
86 tcx.sess.span_bug(lifetime.span, "unresolved lifetime");
89 Some(&rl::DefStaticRegion) => {
93 Some(&rl::DefLateBoundRegion(binder_id, _, id)) => {
94 ty::ReLateBound(binder_id, ty::BrNamed(ast_util::local_def(id),
98 Some(&rl::DefEarlyBoundRegion(space, index, id)) => {
99 ty::ReEarlyBound(id, space, index, lifetime.name)
102 Some(&rl::DefFreeRegion(scope_id, id)) => {
103 ty::ReFree(ty::FreeRegion {
105 bound_region: ty::BrNamed(ast_util::local_def(id),
111 debug!("ast_region_to_region(lifetime={} id={}) yields {}",
112 lifetime_to_str(lifetime),
113 lifetime.id, r.repr(tcx));
118 pub fn opt_ast_region_to_region<AC:AstConv,RS:RegionScope>(
122 opt_lifetime: &Option<ast::Lifetime>) -> ty::Region
124 let r = match *opt_lifetime {
125 Some(ref lifetime) => {
126 ast_region_to_region(this.tcx(), lifetime)
130 match rscope.anon_regions(default_span, 1) {
132 debug!("optional region in illegal location");
133 this.tcx().sess.span_err(
134 default_span, "missing lifetime specifier");
145 debug!("opt_ast_region_to_region(opt_lifetime={:?}) yields {}",
146 opt_lifetime.as_ref().map(|e| lifetime_to_str(e)),
152 fn ast_path_substs<AC:AstConv,RS:RegionScope>(
155 decl_generics: &ty::Generics,
156 self_ty: Option<ty::t>,
157 path: &ast::Path) -> subst::Substs
160 * Given a path `path` that refers to an item `I` with the
161 * declared generics `decl_generics`, returns an appropriate
162 * set of substitutions for this particular reference to `I`.
165 let tcx = this.tcx();
167 // ast_path_substs() is only called to convert paths that are
168 // known to refer to traits, types, or structs. In these cases,
169 // all type parameters defined for the item being referenced will
170 // be in the TypeSpace or SelfSpace.
172 // Note: in the case of traits, the self parameter is also
173 // defined, but we don't currently create a `type_param_def` for
174 // `Self` because it is implicit.
175 assert!(decl_generics.regions.all(|d| d.space == subst::TypeSpace));
176 assert!(decl_generics.types.all(|d| d.space != subst::FnSpace));
178 // If the type is parameterized by the this region, then replace this
179 // region with the current anon region binding (in other words,
180 // whatever & would get replaced with).
181 let expected_num_region_params = decl_generics.regions.len(subst::TypeSpace);
182 let supplied_num_region_params = path.segments.last().unwrap().lifetimes.len();
183 let regions = if expected_num_region_params == supplied_num_region_params {
184 path.segments.last().unwrap().lifetimes.iter().map(
185 |l| ast_region_to_region(this.tcx(), l)).collect::<Vec<_>>()
188 rscope.anon_regions(path.span, expected_num_region_params);
190 if supplied_num_region_params != 0 || anon_regions.is_err() {
193 format!("wrong number of lifetime parameters: \
194 expected {} but found {}",
195 expected_num_region_params,
196 supplied_num_region_params).as_slice());
200 Ok(v) => v.move_iter().collect(),
201 Err(()) => Vec::from_fn(expected_num_region_params,
202 |_| ty::ReStatic) // hokey
206 // Convert the type parameters supplied by the user.
207 let ty_param_defs = decl_generics.types.get_vec(subst::TypeSpace);
208 let supplied_ty_param_count = path.segments.iter().flat_map(|s| s.types.iter()).count();
209 let formal_ty_param_count = ty_param_defs.len();
210 let required_ty_param_count = ty_param_defs.iter()
211 .take_while(|x| x.default.is_none())
213 if supplied_ty_param_count < required_ty_param_count {
214 let expected = if required_ty_param_count < formal_ty_param_count {
219 this.tcx().sess.span_fatal(path.span,
220 format!("wrong number of type arguments: {} {} but found {}",
222 required_ty_param_count,
223 supplied_ty_param_count).as_slice());
224 } else if supplied_ty_param_count > formal_ty_param_count {
225 let expected = if required_ty_param_count < formal_ty_param_count {
230 this.tcx().sess.span_fatal(path.span,
231 format!("wrong number of type arguments: {} {} but found {}",
233 formal_ty_param_count,
234 supplied_ty_param_count).as_slice());
237 if supplied_ty_param_count > required_ty_param_count
238 && !this.tcx().sess.features.default_type_params.get() {
239 this.tcx().sess.span_err(path.span, "default type parameters are \
240 experimental and possibly buggy");
241 this.tcx().sess.span_note(path.span, "add #![feature(default_type_params)] \
242 to the crate attributes to enable");
245 let tps = path.segments.iter().flat_map(|s| s.types.iter())
246 .map(|a_t| ast_ty_to_ty(this, rscope, &**a_t))
249 let mut substs = subst::Substs::new_type(tps, regions);
253 // If no self-type is provided, it's still possible that
254 // one was declared, because this could be an object type.
257 // If a self-type is provided, one should have been
258 // "declared" (in other words, this should be a
260 assert!(decl_generics.types.get_self().is_some());
261 substs.types.push(subst::SelfSpace, ty);
265 for param in ty_param_defs.slice_from(supplied_ty_param_count).iter() {
266 let default = param.default.unwrap();
267 let default = default.subst_spanned(tcx, &substs, Some(path.span));
268 substs.types.push(subst::TypeSpace, default);
274 pub fn ast_path_to_trait_ref<AC:AstConv,RS:RegionScope>(
277 trait_def_id: ast::DefId,
278 self_ty: Option<ty::t>,
279 path: &ast::Path) -> Rc<ty::TraitRef> {
280 let trait_def = this.get_trait_def(trait_def_id);
281 Rc::new(ty::TraitRef {
282 def_id: trait_def_id,
283 substs: ast_path_substs(this, rscope, &trait_def.generics, self_ty, path)
287 pub fn ast_path_to_ty<AC:AstConv,RS:RegionScope>(
292 -> ty_param_substs_and_ty
294 let tcx = this.tcx();
295 let ty::ty_param_bounds_and_ty {
298 } = this.get_item_ty(did);
300 let substs = ast_path_substs(this, rscope, &generics, None, path);
301 let ty = decl_ty.subst(tcx, &substs);
302 ty_param_substs_and_ty { substs: substs, ty: ty }
305 pub static NO_REGIONS: uint = 1;
306 pub static NO_TPS: uint = 2;
308 fn check_path_args(tcx: &ty::ctxt,
311 if (flags & NO_TPS) != 0u {
312 if !path.segments.iter().all(|s| s.types.is_empty()) {
315 "type parameters are not allowed on this type");
319 if (flags & NO_REGIONS) != 0u {
320 if !path.segments.last().unwrap().lifetimes.is_empty() {
323 "region parameters are not allowed on this type");
328 pub fn ast_ty_to_prim_ty(tcx: &ty::ctxt, ast_ty: &ast::Ty) -> Option<ty::t> {
330 ast::TyPath(ref path, _, id) => {
331 let a_def = match tcx.def_map.borrow().find(&id) {
333 tcx.sess.span_bug(ast_ty.span,
334 format!("unbound path {}",
335 path_to_str(path)).as_slice())
340 def::DefPrimTy(nty) => {
343 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
347 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
351 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
352 Some(ty::mk_mach_int(it))
354 ast::TyUint(uit) => {
355 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
356 Some(ty::mk_mach_uint(uit))
358 ast::TyFloat(ft) => {
359 if ft == ast::TyF128 && !tcx.sess.features.quad_precision_float.get() {
360 tcx.sess.span_err(path.span, "quadruple precision floats are \
361 missing complete runtime support");
362 tcx.sess.span_note(path.span, "add \
363 #[feature(quad_precision_float)] \
364 to the crate attributes to enable");
366 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
367 Some(ty::mk_mach_float(ft))
370 tcx.sess.span_err(ast_ty.span,
371 "bare `str` is not a type");
372 // return /something/ so they can at least get more errors
373 Some(ty::mk_uniq(tcx, ty::mk_str(tcx)))
384 /// Converts the given AST type to a built-in type. A "built-in type" is, at
385 /// present, either a core numeric type, a string, or `Box`.
386 pub fn ast_ty_to_builtin_ty<AC:AstConv,
392 match ast_ty_to_prim_ty(this.tcx(), ast_ty) {
393 Some(typ) => return Some(typ),
398 ast::TyPath(ref path, _, id) => {
399 let a_def = match this.tcx().def_map.borrow().find(&id) {
403 .span_bug(ast_ty.span,
404 format!("unbound path {}",
405 path_to_str(path)).as_slice())
410 // FIXME(#12938): This is a hack until we have full support for
413 def::DefTy(did) | def::DefStruct(did)
414 if Some(did) == this.tcx().lang_items.owned_box() => {
417 .flat_map(|s| s.types.iter())
422 "`Box` has only one type parameter")
425 for inner_ast_type in path.segments
427 .flat_map(|s| s.types.iter()) {
428 let mt = ast::MutTy {
430 mutbl: ast::MutImmutable,
432 return Some(mk_pointer(this,
437 match ty::get(typ).sty {
442 "`Box<str>` is not a type");
445 ty::ty_vec(_, None) => {
449 "`Box<[T]>` is not a type");
452 _ => ty::mk_uniq(this.tcx(), typ),
456 this.tcx().sess.span_err(path.span,
457 "not enough type parameters \
458 supplied to `Box<T>`");
461 def::DefTy(did) | def::DefStruct(did)
462 if Some(did) == this.tcx().lang_items.gc() => {
465 .flat_map(|s| s.types.iter())
470 "`Gc` has only one type parameter")
473 for inner_ast_type in path.segments
475 .flat_map(|s| s.types.iter()) {
476 let mt = ast::MutTy {
478 mutbl: ast::MutImmutable,
480 return Some(mk_pointer(this,
485 match ty::get(typ).sty {
490 "`Gc<str>` is not a type");
493 ty::ty_vec(_, None) => {
497 "`Gc<[T]>` is not a type");
500 _ => ty::mk_box(this.tcx(), typ),
504 this.tcx().sess.span_bug(path.span,
505 "not enough type parameters \
506 supplied to `Gc<T>`")
521 fn ast_ty_to_mt<AC:AstConv, RS:RegionScope>(this: &AC,
523 ty: &ast::Ty) -> ty::mt {
524 ty::mt {ty: ast_ty_to_ty(this, rscope, ty), mutbl: ast::MutImmutable}
527 pub fn trait_ref_for_unboxed_function<AC:AstConv,
531 unboxed_function: &ast::UnboxedFnTy,
532 self_ty: Option<ty::t>)
535 let fn_mut_trait_did = this.tcx()
537 .require(FnMutTraitLangItem)
540 unboxed_function.decl
544 ast_ty_to_ty(this, rscope, &*input.ty)
545 }).collect::<Vec<_>>();
546 let input_tuple = ty::mk_tup(this.tcx(), input_types);
547 let output_type = ast_ty_to_ty(this,
549 &*unboxed_function.decl.output);
550 let mut substs = subst::Substs::new_type(vec!(input_tuple, output_type),
554 Some(s) => substs.types.push(subst::SelfSpace, s),
559 def_id: fn_mut_trait_did,
564 // Handle `~`, `Box`, and `&` being able to mean strs and vecs.
565 // If a_seq_ty is a str or a vec, make it a str/vec.
566 // Also handle first-class trait types.
567 fn mk_pointer<AC:AstConv,
571 a_seq_ty: &ast::MutTy,
573 constr: |ty::t| -> ty::t)
575 let tcx = this.tcx();
576 debug!("mk_pointer(ptr_ty={:?})", ptr_ty);
578 match a_seq_ty.ty.node {
579 ast::TyVec(ref ty) => {
580 let mut mt = ast_ty_to_mt(this, rscope, &**ty);
581 if a_seq_ty.mutbl == ast::MutMutable {
582 mt.mutbl = ast::MutMutable;
584 return constr(ty::mk_vec(tcx, mt, None));
586 ast::TyUnboxedFn(ref unboxed_function) => {
590 } = trait_ref_for_unboxed_function(this,
594 let tr = ty::mk_trait(this.tcx(),
597 ty::empty_builtin_bounds());
600 return ty::mk_uniq(this.tcx(), tr);
603 return ty::mk_rptr(this.tcx(),
605 ty::mt {mutbl: a_seq_ty.mutbl, ty: tr});
610 "~trait or &trait are the only supported \
611 forms of casting-to-trait");
617 ast::TyPath(ref path, ref bounds, id) => {
618 // Note that the "bounds must be empty if path is not a trait"
619 // restriction is enforced in the below case for ty_path, which
620 // will run after this as long as the path isn't a trait.
621 match tcx.def_map.borrow().find(&id) {
622 Some(&def::DefPrimTy(ast::TyStr)) => {
623 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
626 return constr(ty::mk_str(tcx));
629 return ty::mk_str_slice(tcx, r, ast::MutImmutable);
634 "managed strings are not supported")
638 Some(&def::DefTrait(trait_def_id)) => {
639 let result = ast_path_to_trait_ref(
640 this, rscope, trait_def_id, None, path);
641 let trait_store = match ptr_ty {
642 Uniq => ty::UniqTraitStore,
644 ty::RegionTraitStore(r, a_seq_ty.mutbl)
649 "~trait or &trait are the only supported \
650 forms of casting-to-trait");
654 let bounds = conv_builtin_bounds(this.tcx(),
658 let tr = ty::mk_trait(tcx,
660 result.substs.clone(),
662 // We could just match on ptr_ty, but we need to pass a trait
663 // store to conv_builtin_bounds, so mathc twice for now.
664 return match trait_store {
665 ty::UniqTraitStore => {
666 return ty::mk_uniq(tcx, tr);
668 ty::RegionTraitStore(r, m) => {
669 return ty::mk_rptr(tcx, r, ty::mt{mutbl: m, ty: tr});
679 constr(ast_ty_to_ty(this, rscope, &*a_seq_ty.ty))
682 // Parses the programmer's textual representation of a type into our
683 // internal notion of a type.
684 pub fn ast_ty_to_ty<AC:AstConv, RS:RegionScope>(
685 this: &AC, rscope: &RS, ast_ty: &ast::Ty) -> ty::t {
687 let tcx = this.tcx();
689 let mut ast_ty_to_ty_cache = tcx.ast_ty_to_ty_cache.borrow_mut();
690 match ast_ty_to_ty_cache.find(&ast_ty.id) {
691 Some(&ty::atttce_resolved(ty)) => return ty,
692 Some(&ty::atttce_unresolved) => {
693 tcx.sess.span_fatal(ast_ty.span,
694 "illegal recursive type; insert an enum \
695 or struct in the cycle, if this is \
698 None => { /* go on */ }
700 ast_ty_to_ty_cache.insert(ast_ty.id, ty::atttce_unresolved);
701 drop(ast_ty_to_ty_cache);
703 let typ = ast_ty_to_builtin_ty(this, rscope, ast_ty).unwrap_or_else(|| {
705 ast::TyNil => ty::mk_nil(),
706 ast::TyBot => ty::mk_bot(),
708 let mt = ast::MutTy { ty: ty, mutbl: ast::MutImmutable };
709 mk_pointer(this, rscope, &mt, Box, |ty| ty::mk_box(tcx, ty))
712 let mt = ast::MutTy { ty: ty, mutbl: ast::MutImmutable };
713 mk_pointer(this, rscope, &mt, Uniq,
714 |ty| ty::mk_uniq(tcx, ty))
717 tcx.sess.span_err(ast_ty.span, "bare `[]` is not a type");
718 // return /something/ so they can at least get more errors
719 let vec_ty = ty::mk_vec(tcx, ast_ty_to_mt(this, rscope, &*ty), None);
720 ty::mk_uniq(tcx, vec_ty)
722 ast::TyPtr(ref mt) => {
723 ty::mk_ptr(tcx, ty::mt {
724 ty: ast_ty_to_ty(this, rscope, &*mt.ty),
728 ast::TyRptr(ref region, ref mt) => {
729 let r = opt_ast_region_to_region(this, rscope, ast_ty.span, region);
730 debug!("ty_rptr r={}", r.repr(this.tcx()));
731 mk_pointer(this, rscope, mt, RPtr(r),
732 |ty| ty::mk_rptr(tcx, r, ty::mt {ty: ty, mutbl: mt.mutbl}))
734 ast::TyTup(ref fields) => {
735 let flds = fields.iter()
736 .map(|t| ast_ty_to_ty(this, rscope, &**t))
738 ty::mk_tup(tcx, flds)
740 ast::TyParen(ref typ) => ast_ty_to_ty(this, rscope, &**typ),
741 ast::TyBareFn(ref bf) => {
742 if bf.decl.variadic && bf.abi != abi::C {
743 tcx.sess.span_err(ast_ty.span,
744 "variadic function must have C calling convention");
746 ty::mk_bare_fn(tcx, ty_of_bare_fn(this, ast_ty.id, bf.fn_style,
749 ast::TyClosure(ref f, ref region) => {
751 // resolve the function bound region in the original region
752 // scope `rscope`, not the scope of the function parameters
753 let bound_region = opt_ast_region_to_region(this, rscope,
754 ast_ty.span, region);
756 let store = ty::RegionTraitStore(bound_region, ast::MutMutable);
758 // Use corresponding trait store to figure out default bounds
759 // if none were specified.
760 let bounds = conv_builtin_bounds(this.tcx(),
765 let fn_decl = ty_of_closure(this,
773 ty::mk_closure(tcx, fn_decl)
775 ast::TyProc(ref f) => {
776 // Use corresponding trait store to figure out default bounds
777 // if none were specified.
778 let bounds = conv_builtin_bounds(this.tcx(),
783 let fn_decl = ty_of_closure(this,
791 ty::mk_closure(tcx, fn_decl)
793 ast::TyUnboxedFn(_) => {
794 tcx.sess.span_err(ast_ty.span,
795 "cannot use unboxed functions here");
798 ast::TyPath(ref path, ref bounds, id) => {
799 let a_def = match tcx.def_map.borrow().find(&id) {
802 .span_bug(ast_ty.span,
803 format!("unbound path {}",
804 path_to_str(path)).as_slice())
808 // Kind bounds on path types are only supported for traits.
810 // But don't emit the error if the user meant to do a trait anyway.
811 def::DefTrait(..) => { },
812 _ if bounds.is_some() =>
813 tcx.sess.span_err(ast_ty.span,
814 "kind bounds can only be used on trait types"),
818 def::DefTrait(_) => {
819 let path_str = path_to_str(path);
822 format!("reference to trait `{name}` where a \
823 type is expected; try `Box<{name}>` or \
825 name=path_str).as_slice());
828 def::DefTy(did) | def::DefStruct(did) => {
829 ast_path_to_ty(this, rscope, did, path).ty
831 def::DefTyParam(space, id, n) => {
832 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
833 ty::mk_param(tcx, space, n, id)
835 def::DefSelfTy(id) => {
836 // n.b.: resolve guarantees that the this type only appears in a
837 // trait, which we rely upon in various places when creating
839 check_path_args(tcx, path, NO_TPS | NO_REGIONS);
840 let did = ast_util::local_def(id);
841 ty::mk_self_type(tcx, did)
844 tcx.sess.span_fatal(ast_ty.span,
845 format!("found module name used as a type: {}",
846 tcx.map.node_to_str(id.node)).as_slice());
848 def::DefPrimTy(_) => {
849 fail!("DefPrimTy arm missed in previous ast_ty_to_prim_ty call");
852 tcx.sess.span_fatal(ast_ty.span,
853 format!("found value name used \
859 ast::TyFixedLengthVec(ty, e) => {
860 match const_eval::eval_const_expr_partial(tcx, &*e) {
863 const_eval::const_int(i) =>
864 ty::mk_vec(tcx, ast_ty_to_mt(this, rscope, &*ty),
866 const_eval::const_uint(i) =>
867 ty::mk_vec(tcx, ast_ty_to_mt(this, rscope, &*ty),
871 ast_ty.span, "expected constant expr for vector length");
878 format!("expected constant expr for vector \
884 ast::TyTypeof(_e) => {
885 tcx.sess.span_bug(ast_ty.span, "typeof is reserved but unimplemented");
888 // TyInfer also appears as the type of arguments or return
889 // values in a ExprFnBlock or ExprProc, or as the type of
890 // local variables. Both of these cases are handled specially
891 // and will not descend into this routine.
892 this.ty_infer(ast_ty.span)
897 tcx.ast_ty_to_ty_cache.borrow_mut().insert(ast_ty.id, ty::atttce_resolved(typ));
901 pub fn ty_of_arg<AC: AstConv, RS: RegionScope>(this: &AC, rscope: &RS, a: &ast::Arg,
902 expected_ty: Option<ty::t>) -> ty::t {
904 ast::TyInfer if expected_ty.is_some() => expected_ty.unwrap(),
905 ast::TyInfer => this.ty_infer(a.ty.span),
906 _ => ast_ty_to_ty(this, rscope, &*a.ty),
911 untransformed_self_ty: ty::t,
912 explicit_self: ast::ExplicitSelf
915 pub fn ty_of_method<AC:AstConv>(
918 fn_style: ast::FnStyle,
919 untransformed_self_ty: ty::t,
920 explicit_self: ast::ExplicitSelf,
924 ty_of_method_or_bare_fn(this, id, fn_style, abi::Rust, Some(SelfInfo {
925 untransformed_self_ty: untransformed_self_ty,
926 explicit_self: explicit_self
930 pub fn ty_of_bare_fn<AC:AstConv>(this: &AC, id: ast::NodeId,
931 fn_style: ast::FnStyle, abi: abi::Abi,
932 decl: &ast::FnDecl) -> ty::BareFnTy {
933 ty_of_method_or_bare_fn(this, id, fn_style, abi, None, decl)
936 fn ty_of_method_or_bare_fn<AC:AstConv>(this: &AC, id: ast::NodeId,
937 fn_style: ast::FnStyle, abi: abi::Abi,
938 opt_self_info: Option<SelfInfo>,
939 decl: &ast::FnDecl) -> ty::BareFnTy {
940 debug!("ty_of_method_or_bare_fn");
942 // new region names that appear inside of the fn decl are bound to
943 // that function type
944 let rb = rscope::BindingRscope::new(id);
946 let self_ty = opt_self_info.and_then(|self_info| {
947 match self_info.explicit_self.node {
948 ast::SelfStatic => None,
950 Some(self_info.untransformed_self_ty)
952 ast::SelfRegion(ref lifetime, mutability) => {
954 opt_ast_region_to_region(this, &rb,
955 self_info.explicit_self.span,
957 Some(ty::mk_rptr(this.tcx(), region,
958 ty::mt {ty: self_info.untransformed_self_ty,
962 Some(ty::mk_uniq(this.tcx(), self_info.untransformed_self_ty))
967 // HACK(eddyb) replace the fake self type in the AST with the actual type.
968 let input_tys = if self_ty.is_some() {
969 decl.inputs.slice_from(1)
971 decl.inputs.as_slice()
973 let input_tys = input_tys.iter().map(|a| ty_of_arg(this, &rb, a, None));
975 let self_and_input_tys = self_ty.move_iter().chain(input_tys).collect();
977 let output_ty = match decl.output.node {
978 ast::TyInfer => this.ty_infer(decl.output.span),
979 _ => ast_ty_to_ty(this, &rb, &*decl.output)
982 return ty::BareFnTy {
987 inputs: self_and_input_tys,
989 variadic: decl.variadic
994 pub fn ty_of_closure<AC:AstConv>(
997 fn_style: ast::FnStyle,
998 onceness: ast::Onceness,
999 bounds: ty::BuiltinBounds,
1000 store: ty::TraitStore,
1002 expected_sig: Option<ty::FnSig>)
1005 debug!("ty_of_fn_decl");
1007 // new region names that appear inside of the fn decl are bound to
1008 // that function type
1009 let rb = rscope::BindingRscope::new(id);
1011 let input_tys = decl.inputs.iter().enumerate().map(|(i, a)| {
1012 let expected_arg_ty = expected_sig.as_ref().and_then(|e| {
1013 // no guarantee that the correct number of expected args
1015 if i < e.inputs.len() {
1016 Some(*e.inputs.get(i))
1021 ty_of_arg(this, &rb, a, expected_arg_ty)
1024 let expected_ret_ty = expected_sig.map(|e| e.output);
1025 let output_ty = match decl.output.node {
1026 ast::TyInfer if expected_ret_ty.is_some() => expected_ret_ty.unwrap(),
1027 ast::TyInfer => this.ty_infer(decl.output.span),
1028 _ => ast_ty_to_ty(this, &rb, &*decl.output)
1036 sig: ty::FnSig {binder_id: id,
1039 variadic: decl.variadic}
1043 fn conv_builtin_bounds(tcx: &ty::ctxt,
1045 ast_bounds: &Option<OwnedSlice<ast::TyParamBound>>,
1046 store: ty::TraitStore)
1047 -> ty::BuiltinBounds {
1048 //! Converts a list of bounds from the AST into a `BuiltinBounds`
1049 //! struct. Reports an error if any of the bounds that appear
1050 //! in the AST refer to general traits and not the built-in traits
1051 //! like `Send`. Used to translate the bounds that
1052 //! appear in closure and trait types, where only builtin bounds are
1054 //! If no bounds were specified, we choose a "default" bound based on
1055 //! the allocation type of the fn/trait, as per issue #7264. The user can
1056 //! override this with an empty bounds list, e.g. "Box<fn:()>" or
1059 match (ast_bounds, store) {
1060 (&Some(ref bound_vec), _) => {
1061 let mut builtin_bounds = ty::empty_builtin_bounds();
1062 for ast_bound in bound_vec.iter() {
1064 ast::TraitTyParamBound(ref b) => {
1065 match lookup_def_tcx(tcx, b.path.span, b.ref_id) {
1066 def::DefTrait(trait_did) => {
1067 if ty::try_add_builtin_trait(tcx, trait_did,
1068 &mut builtin_bounds) {
1069 continue; // success
1074 tcx.sess.span_fatal(
1076 "only the builtin traits can be used as closure \
1079 ast::StaticRegionTyParamBound => {
1080 builtin_bounds.add(ty::BoundStatic);
1082 ast::UnboxedFnTyParamBound(_) => {
1083 tcx.sess.span_err(span,
1084 "unboxed functions are not allowed \
1087 ast::OtherRegionTyParamBound(span) => {
1088 if !tcx.sess.features.issue_5723_bootstrap.get() {
1091 "only the 'static lifetime is accepted \
1099 // &'static Trait is sugar for &'static Trait:'static.
1100 (&None, ty::RegionTraitStore(ty::ReStatic, _)) => {
1101 let mut set = ty::empty_builtin_bounds(); set.add(ty::BoundStatic); set
1103 // No bounds are automatically applied for &'r Trait or ~Trait
1104 (&None, ty::RegionTraitStore(..)) |
1105 (&None, ty::UniqTraitStore) => ty::empty_builtin_bounds(),