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;
14 use llvm::{ValueRef, get_params};
15 use metadata::csearch;
16 use middle::subst::{Subst, Substs};
17 use middle::subst::VecPerParamSpace;
30 use trans::debuginfo::DebugLoc;
32 use trans::expr::SaveIn;
36 use trans::monomorphize;
37 use trans::type_::Type;
38 use trans::type_of::*;
39 use middle::ty::{self, Ty, HasTypeFlags};
40 use middle::ty::MethodCall;
42 use syntax::{ast, attr, visit};
43 use syntax::codemap::DUMMY_SP;
46 // drop_glue pointer, size, align.
47 const VTABLE_OFFSET: usize = 3;
49 /// The main "translation" pass for methods. Generates code
50 /// for non-monomorphized methods only. Other methods will
51 /// be generated once they are invoked with specific type parameters,
52 /// see `trans::base::lval_static_fn()` or `trans::base::monomorphic_fn()`.
53 pub fn trans_impl(ccx: &CrateContext,
55 impl_items: &[P<ast::ImplItem>],
56 generics: &ast::Generics,
58 let _icx = push_ctxt("meth::trans_impl");
61 debug!("trans_impl(name={}, id={})", name, id);
63 let mut v = TransItemVisitor { ccx: ccx };
65 // Both here and below with generic methods, be sure to recurse and look for
66 // items that we need to translate.
67 if !generics.ty_params.is_empty() {
68 for impl_item in impl_items {
69 match impl_item.node {
70 ast::MethodImplItem(..) => {
71 visit::walk_impl_item(&mut v, impl_item);
78 for impl_item in impl_items {
79 match impl_item.node {
80 ast::MethodImplItem(ref sig, ref body) => {
81 if sig.generics.ty_params.is_empty() {
82 let trans_everywhere = attr::requests_inline(&impl_item.attrs);
83 for (ref ccx, is_origin) in ccx.maybe_iter(trans_everywhere) {
84 let llfn = get_item_val(ccx, impl_item.id);
85 let empty_substs = tcx.mk_substs(Substs::trans_empty());
86 trans_fn(ccx, &sig.decl, body, llfn,
87 empty_substs, impl_item.id, &[]);
91 if is_origin { OriginalTranslation } else { InlinedCopy });
94 visit::walk_impl_item(&mut v, impl_item);
101 pub fn trans_method_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
102 method_call: MethodCall,
103 self_expr: Option<&ast::Expr>,
104 arg_cleanup_scope: cleanup::ScopeId)
105 -> Callee<'blk, 'tcx> {
106 let _icx = push_ctxt("meth::trans_method_callee");
108 let method = bcx.tcx().tables.borrow().method_map[&method_call];
110 match bcx.tcx().impl_or_trait_item(method.def_id).container() {
111 ty::ImplContainer(_) => {
112 debug!("trans_method_callee: static, {:?}", method.def_id);
113 let datum = callee::trans_fn_ref(bcx.ccx(),
115 MethodCallKey(method_call),
116 bcx.fcx.param_substs);
124 ty::TraitContainer(trait_def_id) => {
125 let trait_substs = method.substs.clone().method_to_trait();
126 let trait_substs = bcx.tcx().mk_substs(trait_substs);
127 let trait_ref = ty::TraitRef::new(trait_def_id, trait_substs);
129 let trait_ref = ty::Binder(bcx.monomorphize(&trait_ref));
130 let span = bcx.tcx().map.span(method_call.expr_id);
131 debug!("method_call={:?} trait_ref={:?} trait_ref id={:?} substs={:?}",
136 let origin = fulfill_obligation(bcx.ccx(),
139 debug!("origin = {:?}", origin);
140 trans_monomorphized_callee(bcx,
152 pub fn trans_static_method_callee<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
153 method_id: ast::DefId,
154 trait_id: ast::DefId,
155 expr_id: ast::NodeId,
156 param_substs: &'tcx subst::Substs<'tcx>)
157 -> Datum<'tcx, Rvalue>
159 let _icx = push_ctxt("meth::trans_static_method_callee");
162 debug!("trans_static_method_callee(method_id={:?}, trait_id={}, \
165 tcx.item_path_str(trait_id),
168 let mname = if method_id.krate == ast::LOCAL_CRATE {
169 match tcx.map.get(method_id.node) {
170 ast_map::NodeTraitItem(trait_item) => trait_item.ident.name,
171 _ => panic!("callee is not a trait method")
174 csearch::get_item_path(tcx, method_id).last().unwrap().name()
176 debug!("trans_static_method_callee: method_id={:?}, expr_id={}, \
177 name={}", method_id, expr_id, mname);
179 // Find the substitutions for the fn itself. This includes
180 // type parameters that belong to the trait but also some that
181 // belong to the method:
182 let rcvr_substs = node_id_substs(ccx, ExprId(expr_id), param_substs);
183 let subst::SeparateVecsPerParamSpace {
187 } = rcvr_substs.types.split();
189 // Lookup the precise impl being called. To do that, we need to
190 // create a trait reference identifying the self type and other
191 // input type parameters. To create that trait reference, we have
192 // to pick apart the type parameters to identify just those that
193 // pertain to the trait. This is easiest to explain by example:
196 // fn from<U:Foo>(n: U) -> Option<Self>;
199 // let f = <Vec<int> as Convert>::from::<String>(...)
201 // Here, in this call, which I've written with explicit UFCS
202 // notation, the set of type parameters will be:
204 // rcvr_type: [] <-- nothing declared on the trait itself
205 // rcvr_self: [Vec<int>] <-- the self type
206 // rcvr_method: [String] <-- method type parameter
208 // So we create a trait reference using the first two,
209 // basically corresponding to `<Vec<int> as Convert>`.
210 // The remaining type parameters (`rcvr_method`) will be used below.
212 Substs::erased(VecPerParamSpace::new(rcvr_type,
215 let trait_substs = tcx.mk_substs(trait_substs);
216 debug!("trait_substs={:?}", trait_substs);
217 let trait_ref = ty::Binder(ty::TraitRef::new(trait_id, trait_substs));
218 let vtbl = fulfill_obligation(ccx,
222 // Now that we know which impl is being used, we can dispatch to
223 // the actual function:
225 traits::VtableImpl(traits::VtableImplData {
226 impl_def_id: impl_did,
230 assert!(!impl_substs.types.needs_infer());
232 // Create the substitutions that are in scope. This combines
233 // the type parameters from the impl with those declared earlier.
234 // To see what I mean, consider a possible impl:
236 // impl<T> Convert for Vec<T> {
237 // fn from<U:Foo>(n: U) { ... }
240 // Recall that we matched `<Vec<int> as Convert>`. Trait
241 // resolution will have given us a substitution
242 // containing `impl_substs=[[T=int],[],[]]` (the type
243 // parameters defined on the impl). We combine
244 // that with the `rcvr_method` from before, which tells us
245 // the type parameters from the *method*, to yield
246 // `callee_substs=[[T=int],[],[U=String]]`.
247 let subst::SeparateVecsPerParamSpace {
251 } = impl_substs.types.split();
253 Substs::erased(VecPerParamSpace::new(impl_type,
257 let mth_id = method_with_name(ccx, impl_did, mname);
258 trans_fn_ref_with_substs(ccx, mth_id, ExprId(expr_id),
262 traits::VtableObject(ref data) => {
263 let idx = traits::get_vtable_index_of_object_method(tcx, data, method_id);
264 trans_object_shim(ccx,
265 data.upcast_trait_ref.clone(),
270 tcx.sess.bug(&format!("static call to invalid vtable: {:?}",
276 fn method_with_name(ccx: &CrateContext, impl_id: ast::DefId, name: ast::Name)
278 match ccx.impl_method_cache().borrow().get(&(impl_id, name)).cloned() {
283 let impl_items = ccx.tcx().impl_items.borrow();
285 impl_items.get(&impl_id)
286 .expect("could not find impl while translating");
287 let meth_did = impl_items.iter()
289 ccx.tcx().impl_or_trait_item(did.def_id()).name() == name
290 }).expect("could not find method while \
293 ccx.impl_method_cache().borrow_mut().insert((impl_id, name),
298 fn trans_monomorphized_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
299 method_call: MethodCall,
300 self_expr: Option<&ast::Expr>,
301 trait_id: ast::DefId,
302 method_id: ast::DefId,
304 vtable: traits::Vtable<'tcx, ()>,
305 arg_cleanup_scope: cleanup::ScopeId)
306 -> Callee<'blk, 'tcx> {
307 let _icx = push_ctxt("meth::trans_monomorphized_callee");
309 traits::VtableImpl(vtable_impl) => {
311 let impl_did = vtable_impl.impl_def_id;
312 let mname = match ccx.tcx().impl_or_trait_item(method_id) {
313 ty::MethodTraitItem(method) => method.name,
315 bcx.tcx().sess.bug("can't monomorphize a non-method trait \
319 let mth_id = method_with_name(bcx.ccx(), impl_did, mname);
321 // create a concatenated set of substitutions which includes
322 // those from the impl and those from the method:
324 combine_impl_and_methods_tps(
325 bcx, MethodCallKey(method_call), vtable_impl.substs);
327 // translate the function
328 let datum = trans_fn_ref_with_substs(bcx.ccx(),
330 MethodCallKey(method_call),
331 bcx.fcx.param_substs,
334 Callee { bcx: bcx, data: Fn(datum.val), ty: datum.ty }
336 traits::VtableClosure(vtable_closure) => {
337 // The substitutions should have no type parameters remaining
338 // after passing through fulfill_obligation
339 let trait_closure_kind = bcx.tcx().lang_items.fn_trait_kind(trait_id).unwrap();
340 let llfn = closure::trans_closure_method(bcx.ccx(),
341 vtable_closure.closure_def_id,
342 vtable_closure.substs,
347 ty: monomorphize_type(bcx, method_ty)
350 traits::VtableFnPointer(fn_ty) => {
351 let trait_closure_kind = bcx.tcx().lang_items.fn_trait_kind(trait_id).unwrap();
352 let llfn = trans_fn_pointer_shim(bcx.ccx(), trait_closure_kind, fn_ty);
356 ty: monomorphize_type(bcx, method_ty)
359 traits::VtableObject(ref data) => {
360 let idx = traits::get_vtable_index_of_object_method(bcx.tcx(), data, method_id);
361 if let Some(self_expr) = self_expr {
362 if let ty::TyBareFn(_, ref fty) = monomorphize_type(bcx, method_ty).sty {
363 let ty = bcx.tcx().mk_fn(None, opaque_method_ty(bcx.tcx(), fty));
364 return trans_trait_callee(bcx, ty, idx, self_expr, arg_cleanup_scope);
367 let datum = trans_object_shim(bcx.ccx(),
368 data.upcast_trait_ref.clone(),
371 Callee { bcx: bcx, data: Fn(datum.val), ty: datum.ty }
373 traits::VtableBuiltin(..) |
374 traits::VtableDefaultImpl(..) |
375 traits::VtableParam(..) => {
377 &format!("resolved vtable bad vtable {:?} in trans",
383 /// Creates a concatenated set of substitutions which includes those from the impl and those from
384 /// the method. This are some subtle complications here. Statically, we have a list of type
385 /// parameters like `[T0, T1, T2, M1, M2, M3]` where `Tn` are type parameters that appear on the
386 /// receiver. For example, if the receiver is a method parameter `A` with a bound like
387 /// `trait<B,C,D>` then `Tn` would be `[B,C,D]`.
389 /// The weird part is that the type `A` might now be bound to any other type, such as `foo<X>`.
390 /// In that case, the vector we want is: `[X, M1, M2, M3]`. Therefore, what we do now is to slice
391 /// off the method type parameters and append them to the type parameters from the type that the
392 /// receiver is mapped to.
393 fn combine_impl_and_methods_tps<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
394 node: ExprOrMethodCall,
395 rcvr_substs: subst::Substs<'tcx>)
396 -> subst::Substs<'tcx>
400 let node_substs = node_id_substs(ccx, node, bcx.fcx.param_substs);
402 debug!("rcvr_substs={:?}", rcvr_substs);
403 debug!("node_substs={:?}", node_substs);
405 // Break apart the type parameters from the node and type
406 // parameters from the receiver.
407 let node_method = node_substs.types.split().fns;
408 let subst::SeparateVecsPerParamSpace {
412 } = rcvr_substs.types.clone().split();
413 assert!(rcvr_method.is_empty());
415 regions: subst::ErasedRegions,
416 types: subst::VecPerParamSpace::new(rcvr_type, rcvr_self, node_method)
420 /// Create a method callee where the method is coming from a trait object (e.g., Box<Trait> type).
421 /// In this case, we must pull the fn pointer out of the vtable that is packaged up with the
422 /// object. Objects are represented as a pair, so we first evaluate the self expression and then
423 /// extract the self data and vtable out of the pair.
424 fn trans_trait_callee<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
425 opaque_fn_ty: Ty<'tcx>,
427 self_expr: &ast::Expr,
428 arg_cleanup_scope: cleanup::ScopeId)
429 -> Callee<'blk, 'tcx> {
430 let _icx = push_ctxt("meth::trans_trait_callee");
433 // Translate self_datum and take ownership of the value by
434 // converting to an rvalue.
435 let self_datum = unpack_datum!(
436 bcx, expr::trans(bcx, self_expr));
438 let llval = if bcx.fcx.type_needs_drop(self_datum.ty) {
439 let self_datum = unpack_datum!(
440 bcx, self_datum.to_rvalue_datum(bcx, "trait_callee"));
442 // Convert to by-ref since `trans_trait_callee_from_llval` wants it
444 let self_datum = unpack_datum!(
445 bcx, self_datum.to_ref_datum(bcx));
447 // Arrange cleanup in case something should go wrong before the
448 // actual call occurs.
449 self_datum.add_clean(bcx.fcx, arg_cleanup_scope)
451 // We don't have to do anything about cleanups for &Trait and &mut Trait.
452 assert!(self_datum.kind.is_by_ref());
456 let llself = Load(bcx, GEPi(bcx, llval, &[0, abi::FAT_PTR_ADDR]));
457 let llvtable = Load(bcx, GEPi(bcx, llval, &[0, abi::FAT_PTR_EXTRA]));
458 trans_trait_callee_from_llval(bcx, opaque_fn_ty, vtable_index, llself, llvtable)
461 /// Same as `trans_trait_callee()` above, except that it is given a by-ref pointer to the object
463 fn trans_trait_callee_from_llval<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
464 opaque_fn_ty: Ty<'tcx>,
468 -> Callee<'blk, 'tcx> {
469 let _icx = push_ctxt("meth::trans_trait_callee");
472 // Load the data pointer from the object.
473 debug!("trans_trait_callee_from_llval(callee_ty={}, vtable_index={}, llself={}, llvtable={})",
476 bcx.val_to_string(llself),
477 bcx.val_to_string(llvtable));
479 // Replace the self type (&Self or Box<Self>) with an opaque pointer.
480 let mptr = Load(bcx, GEPi(bcx, llvtable, &[vtable_index + VTABLE_OFFSET]));
481 let llcallee_ty = type_of_fn_from_ty(ccx, opaque_fn_ty);
485 data: TraitItem(MethodData {
486 llfn: PointerCast(bcx, mptr, llcallee_ty.ptr_to()),
487 llself: PointerCast(bcx, llself, Type::i8p(ccx)),
493 /// Generate a shim function that allows an object type like `SomeTrait` to
494 /// implement the type `SomeTrait`. Imagine a trait definition:
496 /// trait SomeTrait { fn get(&self) -> int; ... }
498 /// And a generic bit of code:
500 /// fn foo<T:SomeTrait>(t: &T) {
501 /// let x = SomeTrait::get;
505 /// What is the value of `x` when `foo` is invoked with `T=SomeTrait`?
506 /// The answer is that it it is a shim function generate by this
509 /// fn shim(t: &SomeTrait) -> int {
510 /// // ... call t.get() virtually ...
513 /// In fact, all virtual calls can be thought of as normal trait calls
514 /// that go through this shim function.
515 fn trans_object_shim<'a, 'tcx>(
516 ccx: &'a CrateContext<'a, 'tcx>,
517 upcast_trait_ref: ty::PolyTraitRef<'tcx>,
518 method_id: ast::DefId,
520 -> Datum<'tcx, Rvalue>
522 let _icx = push_ctxt("trans_object_shim");
525 debug!("trans_object_shim(upcast_trait_ref={:?}, method_id={:?})",
529 // Upcast to the trait in question and extract out the substitutions.
530 let upcast_trait_ref = tcx.erase_late_bound_regions(&upcast_trait_ref);
531 let object_substs = upcast_trait_ref.substs.clone().erase_regions();
532 debug!("trans_object_shim: object_substs={:?}", object_substs);
534 // Lookup the type of this method as declared in the trait and apply substitutions.
535 let method_ty = match tcx.impl_or_trait_item(method_id) {
536 ty::MethodTraitItem(method) => method,
538 tcx.sess.bug("can't create a method shim for a non-method item")
541 let fty = monomorphize::apply_param_substs(tcx, &object_substs, &method_ty.fty);
542 let fty = tcx.mk_bare_fn(fty);
543 let method_ty = opaque_method_ty(tcx, fty);
544 debug!("trans_object_shim: fty={:?} method_ty={:?}", fty, method_ty);
547 let shim_fn_ty = tcx.mk_fn(None, fty);
548 let method_bare_fn_ty = tcx.mk_fn(None, method_ty);
549 let function_name = link::mangle_internal_name_by_type_and_seq(ccx, shim_fn_ty, "object_shim");
550 let llfn = declare::define_internal_rust_fn(ccx, &function_name, shim_fn_ty);
552 let sig = ccx.tcx().erase_late_bound_regions(&fty.sig);
554 let empty_substs = tcx.mk_substs(Substs::trans_empty());
555 let (block_arena, fcx): (TypedArena<_>, FunctionContext);
556 block_arena = TypedArena::new();
557 fcx = new_fn_ctxt(ccx,
565 let mut bcx = init_function(&fcx, false, sig.output);
567 let llargs = get_params(fcx.llfn);
569 let self_idx = fcx.arg_offset();
570 let llself = llargs[self_idx];
571 let llvtable = llargs[self_idx + 1];
573 debug!("trans_object_shim: llself={}, llvtable={}",
574 bcx.val_to_string(llself), bcx.val_to_string(llvtable));
576 assert!(!fcx.needs_ret_allocas);
579 fcx.llretslotptr.get().map(
580 |_| expr::SaveIn(fcx.get_ret_slot(bcx, sig.output, "ret_slot")));
582 debug!("trans_object_shim: method_offset_in_vtable={}",
585 bcx = trans_call_inner(bcx,
587 |bcx, _| trans_trait_callee_from_llval(bcx,
591 ArgVals(&llargs[(self_idx + 2)..]),
594 finish_fn(&fcx, bcx, sig.output, DebugLoc::None);
596 immediate_rvalue(llfn, shim_fn_ty)
599 /// Creates a returns a dynamic vtable for the given type and vtable origin.
600 /// This is used only for objects.
602 /// The `trait_ref` encodes the erased self type. Hence if we are
603 /// making an object `Foo<Trait>` from a value of type `Foo<T>`, then
604 /// `trait_ref` would map `T:Trait`.
605 pub fn get_vtable<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
606 trait_ref: ty::PolyTraitRef<'tcx>,
607 param_substs: &'tcx subst::Substs<'tcx>)
611 let _icx = push_ctxt("meth::get_vtable");
613 debug!("get_vtable(trait_ref={:?})", trait_ref);
616 match ccx.vtables().borrow().get(&trait_ref) {
617 Some(&val) => { return val }
621 // Not in the cache. Build it.
622 let methods = traits::supertraits(tcx, trait_ref.clone()).flat_map(|trait_ref| {
623 let vtable = fulfill_obligation(ccx, DUMMY_SP, trait_ref.clone());
625 // Should default trait error here?
626 traits::VtableDefaultImpl(_) |
627 traits::VtableBuiltin(_) => {
628 Vec::new().into_iter()
631 traits::VtableImplData {
635 emit_vtable_methods(ccx, id, substs, param_substs).into_iter()
637 traits::VtableClosure(
638 traits::VtableClosureData {
642 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_ref.def_id()).unwrap();
643 let llfn = closure::trans_closure_method(ccx,
647 vec![llfn].into_iter()
649 traits::VtableFnPointer(bare_fn_ty) => {
650 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_ref.def_id()).unwrap();
651 vec![trans_fn_pointer_shim(ccx, trait_closure_kind, bare_fn_ty)].into_iter()
653 traits::VtableObject(ref data) => {
654 // this would imply that the Self type being erased is
655 // an object type; this cannot happen because we
656 // cannot cast an unsized type into a trait object
658 &format!("cannot get vtable for an object type: {:?}",
661 traits::VtableParam(..) => {
663 &format!("resolved vtable for {:?} to bad vtable {:?} in trans",
670 let size_ty = sizing_type_of(ccx, trait_ref.self_ty());
671 let size = machine::llsize_of_alloc(ccx, size_ty);
672 let align = align_of(ccx, trait_ref.self_ty());
674 let components: Vec<_> = vec![
675 // Generate a destructor for the vtable.
676 glue::get_drop_glue(ccx, trait_ref.self_ty()),
679 ].into_iter().chain(methods).collect();
681 let vtable = consts::addr_of(ccx, C_struct(ccx, &components, false), "vtable");
683 ccx.vtables().borrow_mut().insert(trait_ref, vtable);
687 fn emit_vtable_methods<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
689 substs: subst::Substs<'tcx>,
690 param_substs: &'tcx subst::Substs<'tcx>)
695 debug!("emit_vtable_methods(impl_id={:?}, substs={:?}, param_substs={:?})",
700 let trt_id = match tcx.impl_trait_ref(impl_id) {
701 Some(t_id) => t_id.def_id,
702 None => ccx.sess().bug("make_impl_vtable: don't know how to \
703 make a vtable for a type impl!")
706 tcx.populate_implementations_for_trait_if_necessary(trt_id);
708 let nullptr = C_null(Type::nil(ccx).ptr_to());
709 let trait_item_def_ids = tcx.trait_item_def_ids(trt_id);
713 // Filter out non-method items.
714 .filter_map(|item_def_id| {
716 ty::MethodTraitItemId(def_id) => Some(def_id),
721 // Now produce pointers for each remaining method. If the
722 // method could never be called from this object, just supply
724 .map(|trait_method_def_id| {
725 debug!("emit_vtable_methods: trait_method_def_id={:?}",
726 trait_method_def_id);
728 let trait_method_type = match tcx.impl_or_trait_item(trait_method_def_id) {
729 ty::MethodTraitItem(m) => m,
730 _ => ccx.sess().bug("should be a method, not other assoc item"),
732 let name = trait_method_type.name;
734 // Some methods cannot be called on an object; skip those.
735 if !traits::is_vtable_safe_method(tcx, trt_id, &trait_method_type) {
736 debug!("emit_vtable_methods: not vtable safe");
740 debug!("emit_vtable_methods: trait_method_type={:?}",
743 // The substitutions we have are on the impl, so we grab
744 // the method type from the impl to substitute into.
745 let impl_method_def_id = method_with_name(ccx, impl_id, name);
746 let impl_method_type = match tcx.impl_or_trait_item(impl_method_def_id) {
747 ty::MethodTraitItem(m) => m,
748 _ => ccx.sess().bug("should be a method, not other assoc item"),
751 debug!("emit_vtable_methods: impl_method_type={:?}",
754 // If this is a default method, it's possible that it
755 // relies on where clauses that do not hold for this
756 // particular set of type parameters. Note that this
757 // method could then never be called, so we do not want to
758 // try and trans it, in that case. Issue #23435.
759 if tcx.provided_source(impl_method_def_id).is_some() {
760 let predicates = impl_method_type.predicates.predicates.subst(tcx, &substs);
761 if !normalize_and_test_predicates(ccx, predicates.into_vec()) {
762 debug!("emit_vtable_methods: predicates do not hold");
767 trans_fn_ref_with_substs(ccx,
776 /// Replace the self type (&Self or Box<Self>) with an opaque pointer.
777 fn opaque_method_ty<'tcx>(tcx: &ty::ctxt<'tcx>, method_ty: &ty::BareFnTy<'tcx>)
778 -> &'tcx ty::BareFnTy<'tcx> {
779 let mut inputs = method_ty.sig.0.inputs.clone();
780 inputs[0] = tcx.mk_mut_ptr(tcx.mk_mach_int(ast::TyI8));
782 tcx.mk_bare_fn(ty::BareFnTy {
783 unsafety: method_ty.unsafety,
785 sig: ty::Binder(ty::FnSig {
787 output: method_ty.sig.0.output,
788 variadic: method_ty.sig.0.variadic,