1 // Copyright 2012 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.
11 use arena::TypedArena;
13 use llvm::{ValueRef, get_params};
14 use middle::def_id::DefId;
15 use middle::subst::{Subst, Substs};
16 use middle::subst::VecPerParamSpace;
28 use trans::debuginfo::DebugLoc;
30 use trans::expr::SaveIn;
34 use trans::monomorphize;
35 use trans::type_::Type;
36 use trans::type_of::*;
37 use middle::ty::{self, Ty, HasTypeFlags};
38 use middle::ty::MethodCall;
42 use syntax::codemap::DUMMY_SP;
45 use rustc_front::visit;
48 // drop_glue pointer, size, align.
49 const VTABLE_OFFSET: usize = 3;
51 /// The main "translation" pass for methods. Generates code
52 /// for non-monomorphized methods only. Other methods will
53 /// be generated once they are invoked with specific type parameters,
54 /// see `trans::base::lval_static_fn()` or `trans::base::monomorphic_fn()`.
55 pub fn trans_impl(ccx: &CrateContext,
57 impl_items: &[P<hir::ImplItem>],
58 generics: &hir::Generics,
60 let _icx = push_ctxt("meth::trans_impl");
63 debug!("trans_impl(name={}, id={})", name, id);
65 let mut v = TransItemVisitor { ccx: ccx };
67 // Both here and below with generic methods, be sure to recurse and look for
68 // items that we need to translate.
69 if !generics.ty_params.is_empty() {
70 for impl_item in impl_items {
71 match impl_item.node {
72 hir::MethodImplItem(..) => {
73 visit::walk_impl_item(&mut v, impl_item);
80 for impl_item in impl_items {
81 match impl_item.node {
82 hir::MethodImplItem(ref sig, ref body) => {
83 if sig.generics.ty_params.is_empty() {
84 let trans_everywhere = attr::requests_inline(&impl_item.attrs);
85 for (ref ccx, is_origin) in ccx.maybe_iter(trans_everywhere) {
86 let llfn = get_item_val(ccx, impl_item.id);
87 let empty_substs = tcx.mk_substs(Substs::trans_empty());
88 trans_fn(ccx, &sig.decl, body, llfn,
89 empty_substs, impl_item.id, &[]);
93 if is_origin { OriginalTranslation } else { InlinedCopy });
96 visit::walk_impl_item(&mut v, impl_item);
103 pub fn trans_method_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
104 method_call: MethodCall,
105 self_expr: Option<&hir::Expr>,
106 arg_cleanup_scope: cleanup::ScopeId)
107 -> Callee<'blk, 'tcx> {
108 let _icx = push_ctxt("meth::trans_method_callee");
110 let method = bcx.tcx().tables.borrow().method_map[&method_call];
112 match bcx.tcx().impl_or_trait_item(method.def_id).container() {
113 ty::ImplContainer(_) => {
114 debug!("trans_method_callee: static, {:?}", method.def_id);
115 let datum = callee::trans_fn_ref(bcx.ccx(),
117 MethodCallKey(method_call),
118 bcx.fcx.param_substs);
126 ty::TraitContainer(trait_def_id) => {
127 let trait_substs = method.substs.clone().method_to_trait();
128 let trait_substs = bcx.tcx().mk_substs(trait_substs);
129 let trait_ref = ty::TraitRef::new(trait_def_id, trait_substs);
131 let trait_ref = ty::Binder(bcx.monomorphize(&trait_ref));
132 let span = bcx.tcx().map.span(method_call.expr_id);
133 debug!("method_call={:?} trait_ref={:?} trait_ref id={:?} substs={:?}",
138 let origin = fulfill_obligation(bcx.ccx(),
141 debug!("origin = {:?}", origin);
142 trans_monomorphized_callee(bcx,
154 pub fn trans_static_method_callee<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
157 expr_id: ast::NodeId,
158 param_substs: &'tcx subst::Substs<'tcx>)
159 -> Datum<'tcx, Rvalue>
161 let _icx = push_ctxt("meth::trans_static_method_callee");
164 debug!("trans_static_method_callee(method_id={:?}, trait_id={}, \
167 tcx.item_path_str(trait_id),
170 let mname = tcx.item_name(method_id);
172 debug!("trans_static_method_callee: method_id={:?}, expr_id={}, \
173 name={}", method_id, expr_id, mname);
175 // Find the substitutions for the fn itself. This includes
176 // type parameters that belong to the trait but also some that
177 // belong to the method:
178 let rcvr_substs = node_id_substs(ccx, ExprId(expr_id), param_substs);
179 let subst::SeparateVecsPerParamSpace {
183 } = rcvr_substs.types.split();
185 // Lookup the precise impl being called. To do that, we need to
186 // create a trait reference identifying the self type and other
187 // input type parameters. To create that trait reference, we have
188 // to pick apart the type parameters to identify just those that
189 // pertain to the trait. This is easiest to explain by example:
192 // fn from<U:Foo>(n: U) -> Option<Self>;
195 // let f = <Vec<int> as Convert>::from::<String>(...)
197 // Here, in this call, which I've written with explicit UFCS
198 // notation, the set of type parameters will be:
200 // rcvr_type: [] <-- nothing declared on the trait itself
201 // rcvr_self: [Vec<int>] <-- the self type
202 // rcvr_method: [String] <-- method type parameter
204 // So we create a trait reference using the first two,
205 // basically corresponding to `<Vec<int> as Convert>`.
206 // The remaining type parameters (`rcvr_method`) will be used below.
208 Substs::erased(VecPerParamSpace::new(rcvr_type,
211 let trait_substs = tcx.mk_substs(trait_substs);
212 debug!("trait_substs={:?}", trait_substs);
213 let trait_ref = ty::Binder(ty::TraitRef::new(trait_id, trait_substs));
214 let vtbl = fulfill_obligation(ccx,
218 // Now that we know which impl is being used, we can dispatch to
219 // the actual function:
221 traits::VtableImpl(traits::VtableImplData {
222 impl_def_id: impl_did,
226 assert!(!impl_substs.types.needs_infer());
228 // Create the substitutions that are in scope. This combines
229 // the type parameters from the impl with those declared earlier.
230 // To see what I mean, consider a possible impl:
232 // impl<T> Convert for Vec<T> {
233 // fn from<U:Foo>(n: U) { ... }
236 // Recall that we matched `<Vec<int> as Convert>`. Trait
237 // resolution will have given us a substitution
238 // containing `impl_substs=[[T=int],[],[]]` (the type
239 // parameters defined on the impl). We combine
240 // that with the `rcvr_method` from before, which tells us
241 // the type parameters from the *method*, to yield
242 // `callee_substs=[[T=int],[],[U=String]]`.
243 let subst::SeparateVecsPerParamSpace {
247 } = impl_substs.types.split();
249 Substs::erased(VecPerParamSpace::new(impl_type,
253 let mth_id = method_with_name(ccx, impl_did, mname);
254 trans_fn_ref_with_substs(ccx, mth_id, ExprId(expr_id),
258 traits::VtableObject(ref data) => {
259 let idx = traits::get_vtable_index_of_object_method(tcx, data, method_id);
260 trans_object_shim(ccx,
261 data.upcast_trait_ref.clone(),
266 tcx.sess.bug(&format!("static call to invalid vtable: {:?}",
272 fn method_with_name(ccx: &CrateContext, impl_id: DefId, name: ast::Name)
274 match ccx.impl_method_cache().borrow().get(&(impl_id, name)).cloned() {
279 let impl_items = ccx.tcx().impl_items.borrow();
281 impl_items.get(&impl_id)
282 .expect("could not find impl while translating");
283 let meth_did = impl_items.iter()
285 ccx.tcx().impl_or_trait_item(did.def_id()).name() == name
286 }).expect("could not find method while \
289 ccx.impl_method_cache().borrow_mut().insert((impl_id, name),
294 fn trans_monomorphized_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
295 method_call: MethodCall,
296 self_expr: Option<&hir::Expr>,
300 vtable: traits::Vtable<'tcx, ()>,
301 arg_cleanup_scope: cleanup::ScopeId)
302 -> Callee<'blk, 'tcx> {
303 let _icx = push_ctxt("meth::trans_monomorphized_callee");
305 traits::VtableImpl(vtable_impl) => {
307 let impl_did = vtable_impl.impl_def_id;
308 let mname = match ccx.tcx().impl_or_trait_item(method_id) {
309 ty::MethodTraitItem(method) => method.name,
311 bcx.tcx().sess.bug("can't monomorphize a non-method trait \
315 let mth_id = method_with_name(bcx.ccx(), impl_did, mname);
317 // create a concatenated set of substitutions which includes
318 // those from the impl and those from the method:
320 combine_impl_and_methods_tps(
321 bcx, MethodCallKey(method_call), vtable_impl.substs);
323 // translate the function
324 let datum = trans_fn_ref_with_substs(bcx.ccx(),
326 MethodCallKey(method_call),
327 bcx.fcx.param_substs,
330 Callee { bcx: bcx, data: Fn(datum.val), ty: datum.ty }
332 traits::VtableClosure(vtable_closure) => {
333 // The substitutions should have no type parameters remaining
334 // after passing through fulfill_obligation
335 let trait_closure_kind = bcx.tcx().lang_items.fn_trait_kind(trait_id).unwrap();
336 let llfn = closure::trans_closure_method(bcx.ccx(),
337 vtable_closure.closure_def_id,
338 vtable_closure.substs,
343 ty: monomorphize_type(bcx, method_ty)
346 traits::VtableFnPointer(fn_ty) => {
347 let trait_closure_kind = bcx.tcx().lang_items.fn_trait_kind(trait_id).unwrap();
348 let llfn = trans_fn_pointer_shim(bcx.ccx(), trait_closure_kind, fn_ty);
352 ty: monomorphize_type(bcx, method_ty)
355 traits::VtableObject(ref data) => {
356 let idx = traits::get_vtable_index_of_object_method(bcx.tcx(), data, method_id);
357 if let Some(self_expr) = self_expr {
358 if let ty::TyBareFn(_, ref fty) = monomorphize_type(bcx, method_ty).sty {
359 let ty = bcx.tcx().mk_fn(None, opaque_method_ty(bcx.tcx(), fty));
360 return trans_trait_callee(bcx, ty, idx, self_expr, arg_cleanup_scope);
363 let datum = trans_object_shim(bcx.ccx(),
364 data.upcast_trait_ref.clone(),
367 Callee { bcx: bcx, data: Fn(datum.val), ty: datum.ty }
369 traits::VtableBuiltin(..) |
370 traits::VtableDefaultImpl(..) |
371 traits::VtableParam(..) => {
373 &format!("resolved vtable bad vtable {:?} in trans",
379 /// Creates a concatenated set of substitutions which includes those from the impl and those from
380 /// the method. This are some subtle complications here. Statically, we have a list of type
381 /// parameters like `[T0, T1, T2, M1, M2, M3]` where `Tn` are type parameters that appear on the
382 /// receiver. For example, if the receiver is a method parameter `A` with a bound like
383 /// `trait<B,C,D>` then `Tn` would be `[B,C,D]`.
385 /// The weird part is that the type `A` might now be bound to any other type, such as `foo<X>`.
386 /// In that case, the vector we want is: `[X, M1, M2, M3]`. Therefore, what we do now is to slice
387 /// off the method type parameters and append them to the type parameters from the type that the
388 /// receiver is mapped to.
389 fn combine_impl_and_methods_tps<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
390 node: ExprOrMethodCall,
391 rcvr_substs: subst::Substs<'tcx>)
392 -> subst::Substs<'tcx>
396 let node_substs = node_id_substs(ccx, node, bcx.fcx.param_substs);
398 debug!("rcvr_substs={:?}", rcvr_substs);
399 debug!("node_substs={:?}", node_substs);
401 // Break apart the type parameters from the node and type
402 // parameters from the receiver.
403 let node_method = node_substs.types.split().fns;
404 let subst::SeparateVecsPerParamSpace {
408 } = rcvr_substs.types.clone().split();
409 assert!(rcvr_method.is_empty());
411 regions: subst::ErasedRegions,
412 types: subst::VecPerParamSpace::new(rcvr_type, rcvr_self, node_method)
416 /// Create a method callee where the method is coming from a trait object (e.g., Box<Trait> type).
417 /// In this case, we must pull the fn pointer out of the vtable that is packaged up with the
418 /// object. Objects are represented as a pair, so we first evaluate the self expression and then
419 /// extract the self data and vtable out of the pair.
420 fn trans_trait_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
421 opaque_fn_ty: Ty<'tcx>,
423 self_expr: &hir::Expr,
424 arg_cleanup_scope: cleanup::ScopeId)
425 -> Callee<'blk, 'tcx> {
426 let _icx = push_ctxt("meth::trans_trait_callee");
429 // Translate self_datum and take ownership of the value by
430 // converting to an rvalue.
431 let self_datum = unpack_datum!(
432 bcx, expr::trans(bcx, self_expr));
434 let llval = if bcx.fcx.type_needs_drop(self_datum.ty) {
435 let self_datum = unpack_datum!(
436 bcx, self_datum.to_rvalue_datum(bcx, "trait_callee"));
438 // Convert to by-ref since `trans_trait_callee_from_llval` wants it
440 let self_datum = unpack_datum!(
441 bcx, self_datum.to_ref_datum(bcx));
443 // Arrange cleanup in case something should go wrong before the
444 // actual call occurs.
445 self_datum.add_clean(bcx.fcx, arg_cleanup_scope)
447 // We don't have to do anything about cleanups for &Trait and &mut Trait.
448 assert!(self_datum.kind.is_by_ref());
452 let llself = Load(bcx, expr::get_dataptr(bcx, llval));
453 let llvtable = Load(bcx, expr::get_meta(bcx, llval));
454 trans_trait_callee_from_llval(bcx, opaque_fn_ty, vtable_index, llself, llvtable)
457 /// Same as `trans_trait_callee()` above, except that it is given a by-ref pointer to the object
459 fn trans_trait_callee_from_llval<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
460 opaque_fn_ty: Ty<'tcx>,
464 -> Callee<'blk, 'tcx> {
465 let _icx = push_ctxt("meth::trans_trait_callee");
468 // Load the data pointer from the object.
469 debug!("trans_trait_callee_from_llval(callee_ty={}, vtable_index={}, llself={}, llvtable={})",
472 bcx.val_to_string(llself),
473 bcx.val_to_string(llvtable));
475 // Replace the self type (&Self or Box<Self>) with an opaque pointer.
476 let mptr = Load(bcx, GEPi(bcx, llvtable, &[vtable_index + VTABLE_OFFSET]));
477 let llcallee_ty = type_of_fn_from_ty(ccx, opaque_fn_ty);
481 data: TraitItem(MethodData {
482 llfn: PointerCast(bcx, mptr, llcallee_ty.ptr_to()),
483 llself: PointerCast(bcx, llself, Type::i8p(ccx)),
489 /// Generate a shim function that allows an object type like `SomeTrait` to
490 /// implement the type `SomeTrait`. Imagine a trait definition:
492 /// trait SomeTrait { fn get(&self) -> int; ... }
494 /// And a generic bit of code:
496 /// fn foo<T:SomeTrait>(t: &T) {
497 /// let x = SomeTrait::get;
501 /// What is the value of `x` when `foo` is invoked with `T=SomeTrait`?
502 /// The answer is that it it is a shim function generate by this
505 /// fn shim(t: &SomeTrait) -> int {
506 /// // ... call t.get() virtually ...
509 /// In fact, all virtual calls can be thought of as normal trait calls
510 /// that go through this shim function.
511 fn trans_object_shim<'a, 'tcx>(
512 ccx: &'a CrateContext<'a, 'tcx>,
513 upcast_trait_ref: ty::PolyTraitRef<'tcx>,
516 -> Datum<'tcx, Rvalue>
518 let _icx = push_ctxt("trans_object_shim");
521 debug!("trans_object_shim(upcast_trait_ref={:?}, method_id={:?})",
525 // Upcast to the trait in question and extract out the substitutions.
526 let upcast_trait_ref = tcx.erase_late_bound_regions(&upcast_trait_ref);
527 let object_substs = upcast_trait_ref.substs.clone().erase_regions();
528 debug!("trans_object_shim: object_substs={:?}", object_substs);
530 // Lookup the type of this method as declared in the trait and apply substitutions.
531 let method_ty = match tcx.impl_or_trait_item(method_id) {
532 ty::MethodTraitItem(method) => method,
534 tcx.sess.bug("can't create a method shim for a non-method item")
537 let fty = monomorphize::apply_param_substs(tcx, &object_substs, &method_ty.fty);
538 let fty = tcx.mk_bare_fn(fty);
539 let method_ty = opaque_method_ty(tcx, fty);
540 debug!("trans_object_shim: fty={:?} method_ty={:?}", fty, method_ty);
543 let shim_fn_ty = tcx.mk_fn(None, fty);
544 let method_bare_fn_ty = tcx.mk_fn(None, method_ty);
545 let function_name = link::mangle_internal_name_by_type_and_seq(ccx, shim_fn_ty, "object_shim");
546 let llfn = declare::define_internal_rust_fn(ccx, &function_name, shim_fn_ty);
548 let sig = ccx.tcx().erase_late_bound_regions(&fty.sig);
550 let empty_substs = tcx.mk_substs(Substs::trans_empty());
551 let (block_arena, fcx): (TypedArena<_>, FunctionContext);
552 block_arena = TypedArena::new();
553 fcx = new_fn_ctxt(ccx,
561 let mut bcx = init_function(&fcx, false, sig.output);
563 let llargs = get_params(fcx.llfn);
565 let self_idx = fcx.arg_offset();
566 let llself = llargs[self_idx];
567 let llvtable = llargs[self_idx + 1];
569 debug!("trans_object_shim: llself={}, llvtable={}",
570 bcx.val_to_string(llself), bcx.val_to_string(llvtable));
572 assert!(!fcx.needs_ret_allocas);
575 fcx.llretslotptr.get().map(
576 |_| expr::SaveIn(fcx.get_ret_slot(bcx, sig.output, "ret_slot")));
578 debug!("trans_object_shim: method_offset_in_vtable={}",
581 bcx = trans_call_inner(bcx,
583 |bcx, _| trans_trait_callee_from_llval(bcx,
587 ArgVals(&llargs[(self_idx + 2)..]),
590 finish_fn(&fcx, bcx, sig.output, DebugLoc::None);
592 immediate_rvalue(llfn, shim_fn_ty)
595 /// Creates a returns a dynamic vtable for the given type and vtable origin.
596 /// This is used only for objects.
598 /// The `trait_ref` encodes the erased self type. Hence if we are
599 /// making an object `Foo<Trait>` from a value of type `Foo<T>`, then
600 /// `trait_ref` would map `T:Trait`.
601 pub fn get_vtable<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
602 trait_ref: ty::PolyTraitRef<'tcx>,
603 param_substs: &'tcx subst::Substs<'tcx>)
607 let _icx = push_ctxt("meth::get_vtable");
609 debug!("get_vtable(trait_ref={:?})", trait_ref);
612 match ccx.vtables().borrow().get(&trait_ref) {
613 Some(&val) => { return val }
617 // Not in the cache. Build it.
618 let methods = traits::supertraits(tcx, trait_ref.clone()).flat_map(|trait_ref| {
619 let vtable = fulfill_obligation(ccx, DUMMY_SP, trait_ref.clone());
621 // Should default trait error here?
622 traits::VtableDefaultImpl(_) |
623 traits::VtableBuiltin(_) => {
624 Vec::new().into_iter()
627 traits::VtableImplData {
631 emit_vtable_methods(ccx, id, substs, param_substs).into_iter()
633 traits::VtableClosure(
634 traits::VtableClosureData {
638 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_ref.def_id()).unwrap();
639 let llfn = closure::trans_closure_method(ccx,
643 vec![llfn].into_iter()
645 traits::VtableFnPointer(bare_fn_ty) => {
646 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_ref.def_id()).unwrap();
647 vec![trans_fn_pointer_shim(ccx, trait_closure_kind, bare_fn_ty)].into_iter()
649 traits::VtableObject(ref data) => {
650 // this would imply that the Self type being erased is
651 // an object type; this cannot happen because we
652 // cannot cast an unsized type into a trait object
654 &format!("cannot get vtable for an object type: {:?}",
657 traits::VtableParam(..) => {
659 &format!("resolved vtable for {:?} to bad vtable {:?} in trans",
666 let size_ty = sizing_type_of(ccx, trait_ref.self_ty());
667 let size = machine::llsize_of_alloc(ccx, size_ty);
668 let align = align_of(ccx, trait_ref.self_ty());
670 let components: Vec<_> = vec![
671 // Generate a destructor for the vtable.
672 glue::get_drop_glue(ccx, trait_ref.self_ty()),
675 ].into_iter().chain(methods).collect();
677 let vtable = consts::addr_of(ccx, C_struct(ccx, &components, false), "vtable");
679 ccx.vtables().borrow_mut().insert(trait_ref, vtable);
683 fn emit_vtable_methods<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
685 substs: subst::Substs<'tcx>,
686 param_substs: &'tcx subst::Substs<'tcx>)
691 debug!("emit_vtable_methods(impl_id={:?}, substs={:?}, param_substs={:?})",
696 let trt_id = match tcx.impl_trait_ref(impl_id) {
697 Some(t_id) => t_id.def_id,
698 None => ccx.sess().bug("make_impl_vtable: don't know how to \
699 make a vtable for a type impl!")
702 tcx.populate_implementations_for_trait_if_necessary(trt_id);
704 let nullptr = C_null(Type::nil(ccx).ptr_to());
705 let trait_item_def_ids = tcx.trait_item_def_ids(trt_id);
709 // Filter out non-method items.
710 .filter_map(|item_def_id| {
712 ty::MethodTraitItemId(def_id) => Some(def_id),
717 // Now produce pointers for each remaining method. If the
718 // method could never be called from this object, just supply
720 .map(|trait_method_def_id| {
721 debug!("emit_vtable_methods: trait_method_def_id={:?}",
722 trait_method_def_id);
724 let trait_method_type = match tcx.impl_or_trait_item(trait_method_def_id) {
725 ty::MethodTraitItem(m) => m,
726 _ => ccx.sess().bug("should be a method, not other assoc item"),
728 let name = trait_method_type.name;
730 // Some methods cannot be called on an object; skip those.
731 if !traits::is_vtable_safe_method(tcx, trt_id, &trait_method_type) {
732 debug!("emit_vtable_methods: not vtable safe");
736 debug!("emit_vtable_methods: trait_method_type={:?}",
739 // The substitutions we have are on the impl, so we grab
740 // the method type from the impl to substitute into.
741 let impl_method_def_id = method_with_name(ccx, impl_id, name);
742 let impl_method_type = match tcx.impl_or_trait_item(impl_method_def_id) {
743 ty::MethodTraitItem(m) => m,
744 _ => ccx.sess().bug("should be a method, not other assoc item"),
747 debug!("emit_vtable_methods: impl_method_type={:?}",
750 // If this is a default method, it's possible that it
751 // relies on where clauses that do not hold for this
752 // particular set of type parameters. Note that this
753 // method could then never be called, so we do not want to
754 // try and trans it, in that case. Issue #23435.
755 if tcx.provided_source(impl_method_def_id).is_some() {
756 let predicates = impl_method_type.predicates.predicates.subst(tcx, &substs);
757 if !normalize_and_test_predicates(ccx, predicates.into_vec()) {
758 debug!("emit_vtable_methods: predicates do not hold");
763 trans_fn_ref_with_substs(ccx,
772 /// Replace the self type (&Self or Box<Self>) with an opaque pointer.
773 fn opaque_method_ty<'tcx>(tcx: &ty::ctxt<'tcx>, method_ty: &ty::BareFnTy<'tcx>)
774 -> &'tcx ty::BareFnTy<'tcx> {
775 let mut inputs = method_ty.sig.0.inputs.clone();
776 inputs[0] = tcx.mk_mut_ptr(tcx.mk_mach_int(ast::TyI8));
778 tcx.mk_bare_fn(ty::BareFnTy {
779 unsafety: method_ty.unsafety,
781 sig: ty::Binder(ty::FnSig {
783 output: method_ty.sig.0.output,
784 variadic: method_ty.sig.0.variadic,