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 //! Handles translation of callees as well as other call-related
12 //! things. Callees are a superset of normal rust values and sometimes
13 //! have different representations. In particular, top-level fn items
14 //! and methods are represented as just a fn ptr and not a full
17 pub use self::CalleeData::*;
18 pub use self::CallArgs::*;
20 use arena::TypedArena;
21 use back::symbol_names;
22 use llvm::{self, ValueRef, get_params};
23 use middle::cstore::LOCAL_CRATE;
24 use rustc::hir::def_id::DefId;
25 use rustc::ty::subst::Substs;
27 use rustc::hir::map as hir_map;
28 use abi::{Abi, FnType};
35 use cleanup::CleanupMethods;
37 use common::{self, Block, Result, CrateContext, FunctionContext, C_undef};
40 use debuginfo::DebugLoc;
46 use machine::llalign_of_min;
48 use monomorphize::{self, Instance};
49 use trans_item::TransItem;
54 use rustc::ty::{self, Ty, TyCtxt, TypeFoldable};
57 use syntax_pos::DUMMY_SP;
63 /// Constructor for enum variant/tuple-like-struct.
64 NamedTupleConstructor(Disr),
71 /// Trait object found in the vtable at that index.
76 pub struct Callee<'tcx> {
81 impl<'tcx> Callee<'tcx> {
83 pub fn ptr(datum: Datum<'tcx, Rvalue>) -> Callee<'tcx> {
90 /// Trait or impl method call.
91 pub fn method_call<'blk>(bcx: Block<'blk, 'tcx>,
92 method_call: ty::MethodCall)
94 let method = bcx.tcx().tables.borrow().method_map[&method_call];
95 Callee::method(bcx, method)
98 /// Trait or impl method.
99 pub fn method<'blk>(bcx: Block<'blk, 'tcx>,
100 method: ty::MethodCallee<'tcx>) -> Callee<'tcx> {
101 let substs = bcx.fcx.monomorphize(&method.substs);
102 Callee::def(bcx.ccx(), method.def_id, substs)
105 /// Function or method definition.
106 pub fn def<'a>(ccx: &CrateContext<'a, 'tcx>,
108 substs: &'tcx Substs<'tcx>)
112 if let Some(trait_id) = tcx.trait_of_item(def_id) {
113 return Callee::trait_method(ccx, trait_id, def_id, substs);
116 let maybe_node_id = inline::get_local_instance(ccx, def_id)
117 .and_then(|def_id| tcx.map.as_local_node_id(def_id));
118 let maybe_ast_node = maybe_node_id.and_then(|node_id| {
119 tcx.map.find(node_id)
122 let data = match maybe_ast_node {
123 Some(hir_map::NodeStructCtor(_)) => {
124 NamedTupleConstructor(Disr(0))
126 Some(hir_map::NodeVariant(_)) => {
127 let vinfo = common::inlined_variant_def(ccx, maybe_node_id.unwrap());
128 NamedTupleConstructor(Disr::from(vinfo.disr_val))
130 Some(hir_map::NodeForeignItem(fi)) if {
131 let abi = tcx.map.get_foreign_abi(fi.id);
132 abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic
135 _ => return Callee::ptr(get_fn(ccx, def_id, substs))
140 ty: def_ty(tcx, def_id, substs)
144 /// Trait method, which has to be resolved to an impl method.
145 pub fn trait_method<'a>(ccx: &CrateContext<'a, 'tcx>,
148 substs: &'tcx Substs<'tcx>)
152 let trait_ref = ty::TraitRef::from_method(tcx, trait_id, substs);
153 let trait_ref = tcx.normalize_associated_type(&ty::Binder(trait_ref));
154 match common::fulfill_obligation(ccx.shared(), DUMMY_SP, trait_ref) {
155 traits::VtableImpl(vtable_impl) => {
156 let impl_did = vtable_impl.impl_def_id;
157 let mname = tcx.item_name(def_id);
158 // create a concatenated set of substitutions which includes
159 // those from the impl and those from the method:
160 let mth = meth::get_impl_method(tcx, substs, impl_did, vtable_impl.substs, mname);
162 // Translate the function, bypassing Callee::def.
163 // That is because default methods have the same ID as the
164 // trait method used to look up the impl method that ended
165 // up here, so calling Callee::def would infinitely recurse.
166 Callee::ptr(get_fn(ccx, mth.method.def_id, mth.substs))
168 traits::VtableClosure(vtable_closure) => {
169 // The substitutions should have no type parameters remaining
170 // after passing through fulfill_obligation
171 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_id).unwrap();
172 let llfn = closure::trans_closure_method(ccx,
173 vtable_closure.closure_def_id,
174 vtable_closure.substs,
177 let method_ty = def_ty(tcx, def_id, substs);
178 let fn_ptr_ty = match method_ty.sty {
179 ty::TyFnDef(_, _, fty) => tcx.mk_fn_ptr(fty),
180 _ => bug!("expected fn item type, found {}",
183 Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
185 traits::VtableFnPointer(vtable_fn_pointer) => {
186 let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_id).unwrap();
187 let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, vtable_fn_pointer.fn_ty);
189 let method_ty = def_ty(tcx, def_id, substs);
190 let fn_ptr_ty = match method_ty.sty {
191 ty::TyFnDef(_, _, fty) => tcx.mk_fn_ptr(fty),
192 _ => bug!("expected fn item type, found {}",
195 Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty))
197 traits::VtableObject(ref data) => {
199 data: Virtual(tcx.get_vtable_index_of_object_method(data, def_id)),
200 ty: def_ty(tcx, def_id, substs)
204 bug!("resolved vtable bad vtable {:?} in trans", vtable);
209 /// Get the abi::FnType for a direct call. Mainly deals with the fact
210 /// that a Virtual call doesn't take the vtable, like its shim does.
211 /// The extra argument types are for variadic (extern "C") functions.
212 pub fn direct_fn_type<'a>(&self, ccx: &CrateContext<'a, 'tcx>,
213 extra_args: &[Ty<'tcx>]) -> FnType {
214 let abi = self.ty.fn_abi();
215 let sig = ccx.tcx().erase_late_bound_regions(self.ty.fn_sig());
216 let sig = ccx.tcx().normalize_associated_type(&sig);
217 let mut fn_ty = FnType::unadjusted(ccx, abi, &sig, extra_args);
218 if let Virtual(_) = self.data {
219 // Don't pass the vtable, it's not an argument of the virtual fn.
220 fn_ty.args[1].ignore();
222 fn_ty.adjust_for_abi(ccx, abi, &sig);
226 /// This behemoth of a function translates function calls. Unfortunately, in
227 /// order to generate more efficient LLVM output at -O0, it has quite a complex
228 /// signature (refactoring this into two functions seems like a good idea).
230 /// In particular, for lang items, it is invoked with a dest of None, and in
231 /// that case the return value contains the result of the fn. The lang item must
232 /// not return a structural type or else all heck breaks loose.
234 /// For non-lang items, `dest` is always Some, and hence the result is written
235 /// into memory somewhere. Nonetheless we return the actual return value of the
237 pub fn call<'a, 'blk>(self, bcx: Block<'blk, 'tcx>,
239 args: CallArgs<'a, 'tcx>,
240 dest: Option<expr::Dest>)
241 -> Result<'blk, 'tcx> {
242 trans_call_inner(bcx, debug_loc, self, args, dest)
245 /// Turn the callee into a function pointer.
246 pub fn reify<'a>(self, ccx: &CrateContext<'a, 'tcx>)
247 -> Datum<'tcx, Rvalue> {
248 let fn_ptr_ty = match self.ty.sty {
249 ty::TyFnDef(_, _, f) => ccx.tcx().mk_fn_ptr(f),
254 immediate_rvalue(llfn, fn_ptr_ty)
257 let llfn = meth::trans_object_shim(ccx, self.ty, idx);
258 immediate_rvalue(llfn, fn_ptr_ty)
260 NamedTupleConstructor(_) => match self.ty.sty {
261 ty::TyFnDef(def_id, substs, _) => {
262 return get_fn(ccx, def_id, substs);
264 _ => bug!("expected fn item type, found {}", self.ty)
266 Intrinsic => bug!("intrinsic {} getting reified", self.ty)
271 /// Given a DefId and some Substs, produces the monomorphic item type.
272 fn def_ty<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
274 substs: &'tcx Substs<'tcx>)
276 let ty = tcx.lookup_item_type(def_id).ty;
277 monomorphize::apply_param_substs(tcx, substs, &ty)
280 /// Translates an adapter that implements the `Fn` trait for a fn
281 /// pointer. This is basically the equivalent of something like:
284 /// impl<'a> Fn(&'a int) -> &'a int for fn(&int) -> &int {
285 /// extern "rust-abi" fn call(&self, args: (&'a int,)) -> &'a int {
291 /// but for the bare function type given.
292 pub fn trans_fn_pointer_shim<'a, 'tcx>(
293 ccx: &'a CrateContext<'a, 'tcx>,
294 closure_kind: ty::ClosureKind,
295 bare_fn_ty: Ty<'tcx>)
298 let _icx = push_ctxt("trans_fn_pointer_shim");
301 // Normalize the type for better caching.
302 let bare_fn_ty = tcx.normalize_associated_type(&bare_fn_ty);
304 // If this is an impl of `Fn` or `FnMut` trait, the receiver is `&self`.
305 let is_by_ref = match closure_kind {
306 ty::ClosureKind::Fn | ty::ClosureKind::FnMut => true,
307 ty::ClosureKind::FnOnce => false,
310 let llfnpointer = match bare_fn_ty.sty {
311 ty::TyFnDef(def_id, substs, _) => {
312 // Function definitions have to be turned into a pointer.
313 let llfn = Callee::def(ccx, def_id, substs).reify(ccx).val;
315 // A by-value fn item is ignored, so the shim has
316 // the same signature as the original function.
324 let bare_fn_ty_maybe_ref = if is_by_ref {
325 tcx.mk_imm_ref(tcx.mk_region(ty::ReErased), bare_fn_ty)
330 // Check if we already trans'd this shim.
331 match ccx.fn_pointer_shims().borrow().get(&bare_fn_ty_maybe_ref) {
332 Some(&llval) => { return llval; }
336 debug!("trans_fn_pointer_shim(bare_fn_ty={:?})",
339 // Construct the "tuply" version of `bare_fn_ty`. It takes two arguments: `self`,
340 // which is the fn pointer, and `args`, which is the arguments tuple.
341 let sig = match bare_fn_ty.sty {
343 &ty::BareFnTy { unsafety: hir::Unsafety::Normal,
346 ty::TyFnPtr(&ty::BareFnTy { unsafety: hir::Unsafety::Normal,
351 bug!("trans_fn_pointer_shim invoked on invalid type: {}",
355 let sig = tcx.erase_late_bound_regions(sig);
356 let sig = ccx.tcx().normalize_associated_type(&sig);
357 let tuple_input_ty = tcx.mk_tup(sig.inputs.to_vec());
358 let sig = ty::FnSig {
359 inputs: vec![bare_fn_ty_maybe_ref,
364 let fn_ty = FnType::new(ccx, Abi::RustCall, &sig, &[]);
365 let tuple_fn_ty = tcx.mk_fn_ptr(tcx.mk_bare_fn(ty::BareFnTy {
366 unsafety: hir::Unsafety::Normal,
370 debug!("tuple_fn_ty: {:?}", tuple_fn_ty);
374 symbol_names::internal_name_from_type_and_suffix(ccx,
377 let llfn = declare::define_internal_fn(ccx, &function_name, tuple_fn_ty);
378 attributes::set_frame_pointer_elimination(ccx, llfn);
380 let (block_arena, fcx): (TypedArena<_>, FunctionContext);
381 block_arena = TypedArena::new();
382 fcx = FunctionContext::new(ccx, llfn, fn_ty, None, &block_arena);
383 let mut bcx = fcx.init(false, None);
385 let llargs = get_params(fcx.llfn);
387 let self_idx = fcx.fn_ty.ret.is_indirect() as usize;
388 let llfnpointer = llfnpointer.unwrap_or_else(|| {
389 // the first argument (`self`) will be ptr to the fn pointer
391 Load(bcx, llargs[self_idx])
397 assert!(!fcx.needs_ret_allocas);
399 let dest = fcx.llretslotptr.get().map(|_|
400 expr::SaveIn(fcx.get_ret_slot(bcx, "ret_slot"))
403 let callee = Callee {
404 data: Fn(llfnpointer),
407 bcx = callee.call(bcx, DebugLoc::None, ArgVals(&llargs[(self_idx + 1)..]), dest).bcx;
409 fcx.finish(bcx, DebugLoc::None);
411 ccx.fn_pointer_shims().borrow_mut().insert(bare_fn_ty_maybe_ref, llfn);
416 /// Translates a reference to a fn/method item, monomorphizing and
417 /// inlining as it goes.
421 /// - `ccx`: the crate context
422 /// - `def_id`: def id of the fn or method item being referenced
423 /// - `substs`: values for each of the fn/method's parameters
424 fn get_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
426 substs: &'tcx Substs<'tcx>)
427 -> Datum<'tcx, Rvalue> {
430 debug!("get_fn(def_id={:?}, substs={:?})", def_id, substs);
432 assert!(!substs.types.needs_infer());
433 assert!(!substs.types.has_escaping_regions());
435 // Check whether this fn has an inlined copy and, if so, redirect
436 // def_id to the local id of the inlined copy.
437 let def_id = inline::maybe_instantiate_inline(ccx, def_id);
439 fn is_named_tuple_constructor(tcx: TyCtxt, def_id: DefId) -> bool {
440 let node_id = match tcx.map.as_local_node_id(def_id) {
442 None => { return false; }
444 let map_node = errors::expect(
445 &tcx.sess.diagnostic(),
446 tcx.map.find(node_id),
447 || "local item should be in ast map".to_string());
450 hir_map::NodeVariant(v) => {
451 v.node.data.is_tuple()
453 hir_map::NodeStructCtor(_) => true,
457 let must_monomorphise =
458 !substs.types.is_empty() || is_named_tuple_constructor(tcx, def_id);
460 debug!("get_fn({:?}) must_monomorphise: {}",
461 def_id, must_monomorphise);
463 // Create a monomorphic version of generic functions
464 if must_monomorphise {
465 // Should be either intra-crate or inlined.
466 assert_eq!(def_id.krate, LOCAL_CRATE);
468 let substs = tcx.normalize_associated_type(&substs);
469 let (val, fn_ty) = monomorphize::monomorphic_fn(ccx, def_id, substs);
470 let fn_ptr_ty = match fn_ty.sty {
471 ty::TyFnDef(_, _, fty) => {
472 // Create a fn pointer with the substituted signature.
475 _ => bug!("expected fn item type, found {}", fn_ty)
477 assert_eq!(type_of::type_of(ccx, fn_ptr_ty), common::val_ty(val));
478 return immediate_rvalue(val, fn_ptr_ty);
481 // Find the actual function pointer.
482 let ty = ccx.tcx().lookup_item_type(def_id).ty;
483 let fn_ptr_ty = match ty.sty {
484 ty::TyFnDef(_, _, ref fty) => {
485 // Create a fn pointer with the normalized signature.
486 tcx.mk_fn_ptr(tcx.normalize_associated_type(fty))
488 _ => bug!("expected fn item type, found {}", ty)
491 let instance = Instance::mono(ccx.shared(), def_id);
492 if let Some(&llfn) = ccx.instances().borrow().get(&instance) {
493 return immediate_rvalue(llfn, fn_ptr_ty);
496 let local_id = ccx.tcx().map.as_local_node_id(def_id);
497 let local_item = match local_id.and_then(|id| tcx.map.find(id)) {
498 Some(hir_map::NodeItem(&hir::Item {
499 span, node: hir::ItemFn(..), ..
501 Some(hir_map::NodeTraitItem(&hir::TraitItem {
502 span, node: hir::MethodTraitItem(_, Some(_)), ..
504 Some(hir_map::NodeImplItem(&hir::ImplItem {
505 span, node: hir::ImplItemKind::Method(..), ..
512 // This is subtle and surprising, but sometimes we have to bitcast
513 // the resulting fn pointer. The reason has to do with external
514 // functions. If you have two crates that both bind the same C
515 // library, they may not use precisely the same types: for
516 // example, they will probably each declare their own structs,
517 // which are distinct types from LLVM's point of view (nominal
520 // Now, if those two crates are linked into an application, and
521 // they contain inlined code, you can wind up with a situation
522 // where both of those functions wind up being loaded into this
523 // application simultaneously. In that case, the same function
524 // (from LLVM's point of view) requires two types. But of course
525 // LLVM won't allow one function to have two types.
527 // What we currently do, therefore, is declare the function with
528 // one of the two types (whichever happens to come first) and then
529 // bitcast as needed when the function is referenced to make sure
530 // it has the type we expect.
532 // This can occur on either a crate-local or crate-external
533 // reference. It also occurs when testing libcore and in some
534 // other weird situations. Annoying.
536 let sym = ccx.symbol_map().get_or_compute(ccx.shared(),
537 TransItem::Fn(instance));
539 let llptrty = type_of::type_of(ccx, fn_ptr_ty);
540 let llfn = if let Some(llfn) = declare::get_declared_value(ccx, &sym) {
541 if let Some(span) = local_item {
542 if declare::get_defined_value(ccx, &sym).is_some() {
543 ccx.sess().span_fatal(span,
544 &format!("symbol `{}` is already defined", &sym));
548 if common::val_ty(llfn) != llptrty {
549 if local_item.is_some() {
550 bug!("symbol `{}` previously declared as {:?}, now wanted as {:?}",
551 sym, Value(llfn), llptrty);
553 debug!("get_fn: casting {:?} to {:?}", llfn, llptrty);
554 consts::ptrcast(llfn, llptrty)
556 debug!("get_fn: not casting pointer!");
560 let llfn = declare::declare_fn(ccx, &sym, ty);
561 assert_eq!(common::val_ty(llfn), llptrty);
562 debug!("get_fn: not casting pointer!");
564 let attrs = ccx.tcx().get_attrs(def_id);
565 attributes::from_fn_attrs(ccx, &attrs, llfn);
566 if local_item.is_some() {
567 // FIXME(eddyb) Doubt all extern fn should allow unwinding.
568 attributes::unwind(llfn, true);
574 ccx.instances().borrow_mut().insert(instance, llfn);
576 immediate_rvalue(llfn, fn_ptr_ty)
579 // ______________________________________________________________________
582 fn trans_call_inner<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
584 callee: Callee<'tcx>,
585 args: CallArgs<'a, 'tcx>,
586 dest: Option<expr::Dest>)
587 -> Result<'blk, 'tcx> {
588 // Introduce a temporary cleanup scope that will contain cleanups
589 // for the arguments while they are being evaluated. The purpose
590 // this cleanup is to ensure that, should a panic occur while
591 // evaluating argument N, the values for arguments 0...N-1 are all
592 // cleaned up. If no panic occurs, the values are handed off to
593 // the callee, and hence none of the cleanups in this temporary
594 // scope will ever execute.
598 let abi = callee.ty.fn_abi();
599 let sig = callee.ty.fn_sig();
600 let output = bcx.tcx().erase_late_bound_regions(&sig.output());
601 let output = bcx.tcx().normalize_associated_type(&output);
603 let extra_args = match args {
604 ArgExprs(args) if abi != Abi::RustCall => {
605 args[sig.0.inputs.len()..].iter().map(|expr| {
606 common::expr_ty_adjusted(bcx, expr)
611 let fn_ty = callee.direct_fn_type(ccx, &extra_args);
613 let mut callee = match callee.data {
615 assert!(abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic);
616 assert!(dest.is_some());
618 return intrinsic::trans_intrinsic_call(bcx, callee.ty, &fn_ty,
622 NamedTupleConstructor(disr) => {
623 assert!(dest.is_some());
625 return base::trans_named_tuple_constructor(bcx,
635 // Generate a location to store the result. If the user does
636 // not care about the result, just make a stack slot.
637 let opt_llretslot = dest.and_then(|dest| match dest {
638 expr::SaveIn(dst) => Some(dst),
640 let needs_drop = || bcx.fcx.type_needs_drop(output);
641 if fn_ty.ret.is_indirect() || fn_ty.ret.cast.is_some() || needs_drop() {
642 // Push the out-pointer if we use an out-pointer for this
643 // return type, otherwise push "undef".
644 if fn_ty.ret.is_ignore() {
645 Some(C_undef(fn_ty.ret.original_ty.ptr_to()))
647 let llresult = alloca(bcx, fn_ty.ret.original_ty, "__llret");
648 call_lifetime_start(bcx, llresult);
657 // If there no destination, return must be direct, with no cast.
658 if opt_llretslot.is_none() {
659 assert!(!fn_ty.ret.is_indirect() && fn_ty.ret.cast.is_none());
662 let mut llargs = Vec::new();
664 if fn_ty.ret.is_indirect() {
665 let mut llretslot = opt_llretslot.unwrap();
666 if let Some(ty) = fn_ty.ret.cast {
667 llretslot = PointerCast(bcx, llretslot, ty.ptr_to());
669 llargs.push(llretslot);
672 let arg_cleanup_scope = fcx.push_custom_cleanup_scope();
673 bcx = trans_args(bcx, abi, &fn_ty, &mut callee, args, &mut llargs,
674 cleanup::CustomScope(arg_cleanup_scope));
675 fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean();
677 let llfn = match callee {
679 _ => bug!("expected fn pointer callee, found {:?}", callee)
682 let (llret, mut bcx) = base::invoke(bcx, llfn, &llargs, debug_loc);
683 if !bcx.unreachable.get() {
684 fn_ty.apply_attrs_callsite(llret);
686 // If the function we just called does not use an outpointer,
687 // store the result into the rust outpointer. Cast the outpointer
688 // type to match because some ABIs will use a different type than
689 // the Rust type. e.g., a {u32,u32} struct could be returned as
691 if !fn_ty.ret.is_indirect() {
692 if let Some(llretslot) = opt_llretslot {
693 fn_ty.ret.store(&bcx.build(), llret, llretslot);
698 fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_cleanup_scope);
700 // If the caller doesn't care about the result of this fn call,
701 // drop the temporary slot we made.
702 match (dest, opt_llretslot) {
703 (Some(expr::Ignore), Some(llretslot)) => {
704 // drop the value if it is not being saved.
705 bcx = glue::drop_ty(bcx, llretslot, output, debug_loc);
706 call_lifetime_end(bcx, llretslot);
711 // FIXME(canndrew): This is_never should really be an is_uninhabited
712 if output.is_never() {
716 Result::new(bcx, llret)
719 pub enum CallArgs<'a, 'tcx> {
720 /// Supply value of arguments as a list of expressions that must be
721 /// translated. This is used in the common case of `foo(bar, qux)`.
722 ArgExprs(&'a [P<hir::Expr>]),
724 /// Supply value of arguments as a list of LLVM value refs; frequently
725 /// used with lang items and so forth, when the argument is an internal
727 ArgVals(&'a [ValueRef]),
729 /// For overloaded operators: `(lhs, Option(rhs))`.
730 /// `lhs` is the left-hand-side and `rhs` is the datum
731 /// of the right-hand-side argument (if any).
732 ArgOverloadedOp(Datum<'tcx, Expr>, Option<Datum<'tcx, Expr>>),
734 /// Supply value of arguments as a list of expressions that must be
735 /// translated, for overloaded call operators.
736 ArgOverloadedCall(Vec<&'a hir::Expr>),
739 fn trans_args_under_call_abi<'blk, 'tcx>(
740 mut bcx: Block<'blk, 'tcx>,
741 arg_exprs: &[P<hir::Expr>],
742 callee: &mut CalleeData,
744 llargs: &mut Vec<ValueRef>,
745 arg_cleanup_scope: cleanup::ScopeId)
750 // Translate the `self` argument first.
751 let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &arg_exprs[0]));
752 bcx = trans_arg_datum(bcx,
754 callee, fn_ty, &mut arg_idx,
758 // Now untuple the rest of the arguments.
759 let tuple_expr = &arg_exprs[1];
760 let tuple_type = common::node_id_type(bcx, tuple_expr.id);
762 match tuple_type.sty {
763 ty::TyTuple(ref field_types) => {
764 let tuple_datum = unpack_datum!(bcx,
765 expr::trans(bcx, &tuple_expr));
766 let tuple_lvalue_datum =
768 tuple_datum.to_lvalue_datum(bcx,
771 let repr = adt::represent_type(bcx.ccx(), tuple_type);
772 let repr_ptr = &repr;
773 for (i, field_type) in field_types.iter().enumerate() {
774 let arg_datum = tuple_lvalue_datum.get_element(
778 adt::trans_field_ptr(bcx, repr_ptr, srcval, Disr(0), i)
780 bcx = trans_arg_datum(bcx,
782 callee, fn_ty, &mut arg_idx,
788 span_bug!(tuple_expr.span,
789 "argument to `.call()` wasn't a tuple?!")
796 pub fn trans_args<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
799 callee: &mut CalleeData,
800 args: CallArgs<'a, 'tcx>,
801 llargs: &mut Vec<ValueRef>,
802 arg_cleanup_scope: cleanup::ScopeId)
803 -> Block<'blk, 'tcx> {
804 debug!("trans_args(abi={})", abi);
806 let _icx = push_ctxt("trans_args");
811 // First we figure out the caller's view of the types of the arguments.
812 // This will be needed if this is a generic call, because the callee has
813 // to cast her view of the arguments to the caller's view.
815 ArgExprs(arg_exprs) => {
816 if abi == Abi::RustCall {
817 // This is only used for direct calls to the `call`,
818 // `call_mut` or `call_once` functions.
819 return trans_args_under_call_abi(bcx,
820 arg_exprs, callee, fn_ty,
825 for arg_expr in arg_exprs {
826 let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &arg_expr));
827 bcx = trans_arg_datum(bcx,
829 callee, fn_ty, &mut arg_idx,
834 ArgOverloadedCall(arg_exprs) => {
835 for expr in arg_exprs {
837 unpack_datum!(bcx, expr::trans(bcx, expr));
838 bcx = trans_arg_datum(bcx,
840 callee, fn_ty, &mut arg_idx,
845 ArgOverloadedOp(lhs, rhs) => {
846 bcx = trans_arg_datum(bcx, lhs,
847 callee, fn_ty, &mut arg_idx,
851 if let Some(rhs) = rhs {
852 bcx = trans_arg_datum(bcx, rhs,
853 callee, fn_ty, &mut arg_idx,
863 let fn_ptr = meth::get_virtual_method(bcx, vs[1], idx);
864 let llty = fn_ty.llvm_type(bcx.ccx()).ptr_to();
865 *callee = Fn(PointerCast(bcx, fn_ptr, llty));
866 llargs.extend_from_slice(&vs[2..]);
868 _ => llargs.extend_from_slice(vs)
876 fn trans_arg_datum<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
877 arg_datum: Datum<'tcx, Expr>,
878 callee: &mut CalleeData,
880 next_idx: &mut usize,
881 arg_cleanup_scope: cleanup::ScopeId,
882 llargs: &mut Vec<ValueRef>)
883 -> Block<'blk, 'tcx> {
884 let _icx = push_ctxt("trans_arg_datum");
887 debug!("trans_arg_datum({:?})", arg_datum);
889 let arg = &fn_ty.args[*next_idx];
892 // Fill padding with undef value, where applicable.
893 if let Some(ty) = arg.pad {
894 llargs.push(C_undef(ty));
897 // Determine whether we want a by-ref datum even if not appropriate.
898 let want_by_ref = arg.is_indirect() || arg.cast.is_some();
900 let fat_ptr = common::type_is_fat_ptr(bcx.tcx(), arg_datum.ty);
901 let (by_ref, val) = if fat_ptr && !bcx.fcx.type_needs_drop(arg_datum.ty) {
902 (true, arg_datum.val)
904 // Make this an rvalue, since we are going to be
905 // passing ownership.
906 let arg_datum = unpack_datum!(
907 bcx, arg_datum.to_rvalue_datum(bcx, "arg"));
909 // Now that arg_datum is owned, get it into the appropriate
910 // mode (ref vs value).
911 let arg_datum = unpack_datum!(bcx, if want_by_ref {
912 arg_datum.to_ref_datum(bcx)
914 arg_datum.to_appropriate_datum(bcx)
917 // Technically, ownership of val passes to the callee.
918 // However, we must cleanup should we panic before the
919 // callee is actually invoked.
920 (arg_datum.kind.is_by_ref(),
921 arg_datum.add_clean(bcx.fcx, arg_cleanup_scope))
928 debug!("--- trans_arg_datum passing {:?}", Value(val));
931 // Fat pointers should be passed without any transformations.
932 assert!(!arg.is_indirect() && arg.cast.is_none());
933 llargs.push(Load(bcx, expr::get_dataptr(bcx, val)));
935 let info_arg = &fn_ty.args[*next_idx];
937 assert!(!info_arg.is_indirect() && info_arg.cast.is_none());
938 let info = Load(bcx, expr::get_meta(bcx, val));
940 if let Virtual(idx) = *callee {
941 // We have to grab the fn pointer from the vtable when
942 // handling the first argument, ensure that here.
943 assert_eq!(*next_idx, 2);
944 assert!(info_arg.is_ignore());
945 let fn_ptr = meth::get_virtual_method(bcx, info, idx);
946 let llty = fn_ty.llvm_type(bcx.ccx()).ptr_to();
947 *callee = Fn(PointerCast(bcx, fn_ptr, llty));
949 assert!(!info_arg.is_ignore());
956 if by_ref && !arg.is_indirect() {
957 // Have to load the argument, maybe while casting it.
958 if arg.original_ty == Type::i1(bcx.ccx()) {
959 // We store bools as i8 so we need to truncate to i1.
960 val = LoadRangeAssert(bcx, val, 0, 2, llvm::False);
961 val = Trunc(bcx, val, arg.original_ty);
962 } else if let Some(ty) = arg.cast {
963 val = Load(bcx, PointerCast(bcx, val, ty.ptr_to()));
964 if !bcx.unreachable.get() {
965 let llalign = llalign_of_min(bcx.ccx(), arg.ty);
967 llvm::LLVMSetAlignment(val, llalign);
971 val = Load(bcx, val);