| // Copyright 2012 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| //! Handles translation of callees as well as other call-related |
| //! things. Callees are a superset of normal rust values and sometimes |
| //! have different representations. In particular, top-level fn items |
| //! and methods are represented as just a fn ptr and not a full |
| //! closure. |
| |
| pub use self::CalleeData::*; |
| pub use self::CallArgs::*; |
| |
| use arena::TypedArena; |
| use back::symbol_names; |
| use llvm::{self, ValueRef, get_params}; |
| use middle::cstore::LOCAL_CRATE; |
| use rustc::hir::def_id::DefId; |
| use rustc::ty::subst; |
| use rustc::traits; |
| use rustc::hir::map as hir_map; |
| use abi::{Abi, FnType}; |
| use adt; |
| use attributes; |
| use base; |
| use base::*; |
| use build::*; |
| use cleanup; |
| use cleanup::CleanupMethods; |
| use closure; |
| use common::{self, Block, Result, CrateContext, FunctionContext, C_undef}; |
| use consts; |
| use datum::*; |
| use debuginfo::DebugLoc; |
| use declare; |
| use expr; |
| use glue; |
| use inline; |
| use intrinsic; |
| use machine::llalign_of_min; |
| use meth; |
| use monomorphize::{self, Instance}; |
| use trans_item::TransItem; |
| use type_::Type; |
| use type_of; |
| use value::Value; |
| use Disr; |
| use rustc::ty::{self, Ty, TyCtxt, TypeFoldable}; |
| use rustc::hir; |
| |
| use syntax_pos::DUMMY_SP; |
| use errors; |
| use syntax::ptr::P; |
| |
| #[derive(Debug)] |
| pub enum CalleeData { |
| /// Constructor for enum variant/tuple-like-struct. |
| NamedTupleConstructor(Disr), |
| |
| /// Function pointer. |
| Fn(ValueRef), |
| |
| Intrinsic, |
| |
| /// Trait object found in the vtable at that index. |
| Virtual(usize) |
| } |
| |
| #[derive(Debug)] |
| pub struct Callee<'tcx> { |
| pub data: CalleeData, |
| pub ty: Ty<'tcx> |
| } |
| |
| impl<'tcx> Callee<'tcx> { |
| /// Function pointer. |
| pub fn ptr(datum: Datum<'tcx, Rvalue>) -> Callee<'tcx> { |
| Callee { |
| data: Fn(datum.val), |
| ty: datum.ty |
| } |
| } |
| |
| /// Trait or impl method call. |
| pub fn method_call<'blk>(bcx: Block<'blk, 'tcx>, |
| method_call: ty::MethodCall) |
| -> Callee<'tcx> { |
| let method = bcx.tcx().tables.borrow().method_map[&method_call]; |
| Callee::method(bcx, method) |
| } |
| |
| /// Trait or impl method. |
| pub fn method<'blk>(bcx: Block<'blk, 'tcx>, |
| method: ty::MethodCallee<'tcx>) -> Callee<'tcx> { |
| let substs = bcx.fcx.monomorphize(&method.substs); |
| Callee::def(bcx.ccx(), method.def_id, substs) |
| } |
| |
| /// Function or method definition. |
| pub fn def<'a>(ccx: &CrateContext<'a, 'tcx>, |
| def_id: DefId, |
| substs: &'tcx subst::Substs<'tcx>) |
| -> Callee<'tcx> { |
| let tcx = ccx.tcx(); |
| |
| if substs.self_ty().is_some() { |
| // Only trait methods can have a Self parameter. |
| return Callee::trait_method(ccx, def_id, substs); |
| } |
| |
| let maybe_node_id = inline::get_local_instance(ccx, def_id) |
| .and_then(|def_id| tcx.map.as_local_node_id(def_id)); |
| let maybe_ast_node = maybe_node_id.and_then(|node_id| { |
| tcx.map.find(node_id) |
| }); |
| |
| let data = match maybe_ast_node { |
| Some(hir_map::NodeStructCtor(_)) => { |
| NamedTupleConstructor(Disr(0)) |
| } |
| Some(hir_map::NodeVariant(_)) => { |
| let vinfo = common::inlined_variant_def(ccx, maybe_node_id.unwrap()); |
| NamedTupleConstructor(Disr::from(vinfo.disr_val)) |
| } |
| Some(hir_map::NodeForeignItem(fi)) if { |
| let abi = tcx.map.get_foreign_abi(fi.id); |
| abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic |
| } => Intrinsic, |
| |
| _ => return Callee::ptr(get_fn(ccx, def_id, substs)) |
| }; |
| |
| Callee { |
| data: data, |
| ty: def_ty(tcx, def_id, substs) |
| } |
| } |
| |
| /// Trait method, which has to be resolved to an impl method. |
| pub fn trait_method<'a>(ccx: &CrateContext<'a, 'tcx>, |
| def_id: DefId, |
| substs: &'tcx subst::Substs<'tcx>) |
| -> Callee<'tcx> { |
| let tcx = ccx.tcx(); |
| |
| let method_item = tcx.impl_or_trait_item(def_id); |
| let trait_id = method_item.container().id(); |
| let trait_ref = ty::Binder(substs.to_trait_ref(tcx, trait_id)); |
| let trait_ref = tcx.normalize_associated_type(&trait_ref); |
| match common::fulfill_obligation(ccx.shared(), DUMMY_SP, trait_ref) { |
| traits::VtableImpl(vtable_impl) => { |
| let impl_did = vtable_impl.impl_def_id; |
| let mname = tcx.item_name(def_id); |
| // create a concatenated set of substitutions which includes |
| // those from the impl and those from the method: |
| let impl_substs = vtable_impl.substs.with_method_from(&substs); |
| let substs = tcx.mk_substs(impl_substs); |
| let mth = meth::get_impl_method(tcx, impl_did, substs, mname); |
| |
| // Translate the function, bypassing Callee::def. |
| // That is because default methods have the same ID as the |
| // trait method used to look up the impl method that ended |
| // up here, so calling Callee::def would infinitely recurse. |
| Callee::ptr(get_fn(ccx, mth.method.def_id, mth.substs)) |
| } |
| traits::VtableClosure(vtable_closure) => { |
| // The substitutions should have no type parameters remaining |
| // after passing through fulfill_obligation |
| let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_id).unwrap(); |
| let llfn = closure::trans_closure_method(ccx, |
| vtable_closure.closure_def_id, |
| vtable_closure.substs, |
| trait_closure_kind); |
| |
| let method_ty = def_ty(tcx, def_id, substs); |
| let fn_ptr_ty = match method_ty.sty { |
| ty::TyFnDef(_, _, fty) => tcx.mk_fn_ptr(fty), |
| _ => bug!("expected fn item type, found {}", |
| method_ty) |
| }; |
| Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty)) |
| } |
| traits::VtableFnPointer(vtable_fn_pointer) => { |
| let trait_closure_kind = tcx.lang_items.fn_trait_kind(trait_id).unwrap(); |
| let llfn = trans_fn_pointer_shim(ccx, trait_closure_kind, vtable_fn_pointer.fn_ty); |
| |
| let method_ty = def_ty(tcx, def_id, substs); |
| let fn_ptr_ty = match method_ty.sty { |
| ty::TyFnDef(_, _, fty) => tcx.mk_fn_ptr(fty), |
| _ => bug!("expected fn item type, found {}", |
| method_ty) |
| }; |
| Callee::ptr(immediate_rvalue(llfn, fn_ptr_ty)) |
| } |
| traits::VtableObject(ref data) => { |
| Callee { |
| data: Virtual(tcx.get_vtable_index_of_object_method(data, def_id)), |
| ty: def_ty(tcx, def_id, substs) |
| } |
| } |
| vtable => { |
| bug!("resolved vtable bad vtable {:?} in trans", vtable); |
| } |
| } |
| } |
| |
| /// Get the abi::FnType for a direct call. Mainly deals with the fact |
| /// that a Virtual call doesn't take the vtable, like its shim does. |
| /// The extra argument types are for variadic (extern "C") functions. |
| pub fn direct_fn_type<'a>(&self, ccx: &CrateContext<'a, 'tcx>, |
| extra_args: &[Ty<'tcx>]) -> FnType { |
| let abi = self.ty.fn_abi(); |
| let sig = ccx.tcx().erase_late_bound_regions(self.ty.fn_sig()); |
| let sig = ccx.tcx().normalize_associated_type(&sig); |
| let mut fn_ty = FnType::unadjusted(ccx, abi, &sig, extra_args); |
| if let Virtual(_) = self.data { |
| // Don't pass the vtable, it's not an argument of the virtual fn. |
| fn_ty.args[1].ignore(); |
| } |
| fn_ty.adjust_for_abi(ccx, abi, &sig); |
| fn_ty |
| } |
| |
| /// This behemoth of a function translates function calls. Unfortunately, in |
| /// order to generate more efficient LLVM output at -O0, it has quite a complex |
| /// signature (refactoring this into two functions seems like a good idea). |
| /// |
| /// In particular, for lang items, it is invoked with a dest of None, and in |
| /// that case the return value contains the result of the fn. The lang item must |
| /// not return a structural type or else all heck breaks loose. |
| /// |
| /// For non-lang items, `dest` is always Some, and hence the result is written |
| /// into memory somewhere. Nonetheless we return the actual return value of the |
| /// function. |
| pub fn call<'a, 'blk>(self, bcx: Block<'blk, 'tcx>, |
| debug_loc: DebugLoc, |
| args: CallArgs<'a, 'tcx>, |
| dest: Option<expr::Dest>) |
| -> Result<'blk, 'tcx> { |
| trans_call_inner(bcx, debug_loc, self, args, dest) |
| } |
| |
| /// Turn the callee into a function pointer. |
| pub fn reify<'a>(self, ccx: &CrateContext<'a, 'tcx>) |
| -> Datum<'tcx, Rvalue> { |
| let fn_ptr_ty = match self.ty.sty { |
| ty::TyFnDef(_, _, f) => ccx.tcx().mk_fn_ptr(f), |
| _ => self.ty |
| }; |
| match self.data { |
| Fn(llfn) => { |
| immediate_rvalue(llfn, fn_ptr_ty) |
| } |
| Virtual(idx) => { |
| let llfn = meth::trans_object_shim(ccx, self.ty, idx); |
| immediate_rvalue(llfn, fn_ptr_ty) |
| } |
| NamedTupleConstructor(_) => match self.ty.sty { |
| ty::TyFnDef(def_id, substs, _) => { |
| return get_fn(ccx, def_id, substs); |
| } |
| _ => bug!("expected fn item type, found {}", self.ty) |
| }, |
| Intrinsic => bug!("intrinsic {} getting reified", self.ty) |
| } |
| } |
| } |
| |
| /// Given a DefId and some Substs, produces the monomorphic item type. |
| fn def_ty<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| substs: &'tcx subst::Substs<'tcx>) |
| -> Ty<'tcx> { |
| let ty = tcx.lookup_item_type(def_id).ty; |
| monomorphize::apply_param_substs(tcx, substs, &ty) |
| } |
| |
| /// Translates an adapter that implements the `Fn` trait for a fn |
| /// pointer. This is basically the equivalent of something like: |
| /// |
| /// ``` |
| /// impl<'a> Fn(&'a int) -> &'a int for fn(&int) -> &int { |
| /// extern "rust-abi" fn call(&self, args: (&'a int,)) -> &'a int { |
| /// (*self)(args.0) |
| /// } |
| /// } |
| /// ``` |
| /// |
| /// but for the bare function type given. |
| pub fn trans_fn_pointer_shim<'a, 'tcx>( |
| ccx: &'a CrateContext<'a, 'tcx>, |
| closure_kind: ty::ClosureKind, |
| bare_fn_ty: Ty<'tcx>) |
| -> ValueRef |
| { |
| let _icx = push_ctxt("trans_fn_pointer_shim"); |
| let tcx = ccx.tcx(); |
| |
| // Normalize the type for better caching. |
| let bare_fn_ty = tcx.normalize_associated_type(&bare_fn_ty); |
| |
| // If this is an impl of `Fn` or `FnMut` trait, the receiver is `&self`. |
| let is_by_ref = match closure_kind { |
| ty::ClosureKind::Fn | ty::ClosureKind::FnMut => true, |
| ty::ClosureKind::FnOnce => false, |
| }; |
| |
| let llfnpointer = match bare_fn_ty.sty { |
| ty::TyFnDef(def_id, substs, _) => { |
| // Function definitions have to be turned into a pointer. |
| let llfn = Callee::def(ccx, def_id, substs).reify(ccx).val; |
| if !is_by_ref { |
| // A by-value fn item is ignored, so the shim has |
| // the same signature as the original function. |
| return llfn; |
| } |
| Some(llfn) |
| } |
| _ => None |
| }; |
| |
| let bare_fn_ty_maybe_ref = if is_by_ref { |
| tcx.mk_imm_ref(tcx.mk_region(ty::ReErased), bare_fn_ty) |
| } else { |
| bare_fn_ty |
| }; |
| |
| // Check if we already trans'd this shim. |
| match ccx.fn_pointer_shims().borrow().get(&bare_fn_ty_maybe_ref) { |
| Some(&llval) => { return llval; } |
| None => { } |
| } |
| |
| debug!("trans_fn_pointer_shim(bare_fn_ty={:?})", |
| bare_fn_ty); |
| |
| // Construct the "tuply" version of `bare_fn_ty`. It takes two arguments: `self`, |
| // which is the fn pointer, and `args`, which is the arguments tuple. |
| let sig = match bare_fn_ty.sty { |
| ty::TyFnDef(_, _, |
| &ty::BareFnTy { unsafety: hir::Unsafety::Normal, |
| abi: Abi::Rust, |
| ref sig }) | |
| ty::TyFnPtr(&ty::BareFnTy { unsafety: hir::Unsafety::Normal, |
| abi: Abi::Rust, |
| ref sig }) => sig, |
| |
| _ => { |
| bug!("trans_fn_pointer_shim invoked on invalid type: {}", |
| bare_fn_ty); |
| } |
| }; |
| let sig = tcx.erase_late_bound_regions(sig); |
| let sig = ccx.tcx().normalize_associated_type(&sig); |
| let tuple_input_ty = tcx.mk_tup(sig.inputs.to_vec()); |
| let sig = ty::FnSig { |
| inputs: vec![bare_fn_ty_maybe_ref, |
| tuple_input_ty], |
| output: sig.output, |
| variadic: false |
| }; |
| let fn_ty = FnType::new(ccx, Abi::RustCall, &sig, &[]); |
| let tuple_fn_ty = tcx.mk_fn_ptr(tcx.mk_bare_fn(ty::BareFnTy { |
| unsafety: hir::Unsafety::Normal, |
| abi: Abi::RustCall, |
| sig: ty::Binder(sig) |
| })); |
| debug!("tuple_fn_ty: {:?}", tuple_fn_ty); |
| |
| // |
| let function_name = |
| symbol_names::internal_name_from_type_and_suffix(ccx, |
| bare_fn_ty, |
| "fn_pointer_shim"); |
| let llfn = declare::define_internal_fn(ccx, &function_name, tuple_fn_ty); |
| attributes::set_frame_pointer_elimination(ccx, llfn); |
| // |
| let (block_arena, fcx): (TypedArena<_>, FunctionContext); |
| block_arena = TypedArena::new(); |
| fcx = FunctionContext::new(ccx, llfn, fn_ty, None, &block_arena); |
| let mut bcx = fcx.init(false, None); |
| |
| let llargs = get_params(fcx.llfn); |
| |
| let self_idx = fcx.fn_ty.ret.is_indirect() as usize; |
| let llfnpointer = llfnpointer.unwrap_or_else(|| { |
| // the first argument (`self`) will be ptr to the fn pointer |
| if is_by_ref { |
| Load(bcx, llargs[self_idx]) |
| } else { |
| llargs[self_idx] |
| } |
| }); |
| |
| assert!(!fcx.needs_ret_allocas); |
| |
| let dest = fcx.llretslotptr.get().map(|_| |
| expr::SaveIn(fcx.get_ret_slot(bcx, "ret_slot")) |
| ); |
| |
| let callee = Callee { |
| data: Fn(llfnpointer), |
| ty: bare_fn_ty |
| }; |
| bcx = callee.call(bcx, DebugLoc::None, ArgVals(&llargs[(self_idx + 1)..]), dest).bcx; |
| |
| fcx.finish(bcx, DebugLoc::None); |
| |
| ccx.fn_pointer_shims().borrow_mut().insert(bare_fn_ty_maybe_ref, llfn); |
| |
| llfn |
| } |
| |
| /// Translates a reference to a fn/method item, monomorphizing and |
| /// inlining as it goes. |
| /// |
| /// # Parameters |
| /// |
| /// - `ccx`: the crate context |
| /// - `def_id`: def id of the fn or method item being referenced |
| /// - `substs`: values for each of the fn/method's parameters |
| fn get_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, |
| def_id: DefId, |
| substs: &'tcx subst::Substs<'tcx>) |
| -> Datum<'tcx, Rvalue> { |
| let tcx = ccx.tcx(); |
| |
| debug!("get_fn(def_id={:?}, substs={:?})", def_id, substs); |
| |
| assert!(!substs.types.needs_infer()); |
| assert!(!substs.types.has_escaping_regions()); |
| |
| // Check whether this fn has an inlined copy and, if so, redirect |
| // def_id to the local id of the inlined copy. |
| let def_id = inline::maybe_instantiate_inline(ccx, def_id); |
| |
| fn is_named_tuple_constructor(tcx: TyCtxt, def_id: DefId) -> bool { |
| let node_id = match tcx.map.as_local_node_id(def_id) { |
| Some(n) => n, |
| None => { return false; } |
| }; |
| let map_node = errors::expect( |
| &tcx.sess.diagnostic(), |
| tcx.map.find(node_id), |
| || "local item should be in ast map".to_string()); |
| |
| match map_node { |
| hir_map::NodeVariant(v) => { |
| v.node.data.is_tuple() |
| } |
| hir_map::NodeStructCtor(_) => true, |
| _ => false |
| } |
| } |
| let must_monomorphise = |
| !substs.types.is_empty() || is_named_tuple_constructor(tcx, def_id); |
| |
| debug!("get_fn({:?}) must_monomorphise: {}", |
| def_id, must_monomorphise); |
| |
| // Create a monomorphic version of generic functions |
| if must_monomorphise { |
| // Should be either intra-crate or inlined. |
| assert_eq!(def_id.krate, LOCAL_CRATE); |
| |
| let substs = tcx.normalize_associated_type(&substs); |
| let (val, fn_ty) = monomorphize::monomorphic_fn(ccx, def_id, substs); |
| let fn_ptr_ty = match fn_ty.sty { |
| ty::TyFnDef(_, _, fty) => { |
| // Create a fn pointer with the substituted signature. |
| tcx.mk_fn_ptr(fty) |
| } |
| _ => bug!("expected fn item type, found {}", fn_ty) |
| }; |
| assert_eq!(type_of::type_of(ccx, fn_ptr_ty), common::val_ty(val)); |
| return immediate_rvalue(val, fn_ptr_ty); |
| } |
| |
| // Find the actual function pointer. |
| let ty = ccx.tcx().lookup_item_type(def_id).ty; |
| let fn_ptr_ty = match ty.sty { |
| ty::TyFnDef(_, _, ref fty) => { |
| // Create a fn pointer with the normalized signature. |
| tcx.mk_fn_ptr(tcx.normalize_associated_type(fty)) |
| } |
| _ => bug!("expected fn item type, found {}", ty) |
| }; |
| |
| let instance = Instance::mono(ccx.shared(), def_id); |
| if let Some(&llfn) = ccx.instances().borrow().get(&instance) { |
| return immediate_rvalue(llfn, fn_ptr_ty); |
| } |
| |
| let local_id = ccx.tcx().map.as_local_node_id(def_id); |
| let local_item = match local_id.and_then(|id| tcx.map.find(id)) { |
| Some(hir_map::NodeItem(&hir::Item { |
| span, node: hir::ItemFn(..), .. |
| })) | |
| Some(hir_map::NodeTraitItem(&hir::TraitItem { |
| span, node: hir::MethodTraitItem(_, Some(_)), .. |
| })) | |
| Some(hir_map::NodeImplItem(&hir::ImplItem { |
| span, node: hir::ImplItemKind::Method(..), .. |
| })) => { |
| Some(span) |
| } |
| _ => None |
| }; |
| |
| // This is subtle and surprising, but sometimes we have to bitcast |
| // the resulting fn pointer. The reason has to do with external |
| // functions. If you have two crates that both bind the same C |
| // library, they may not use precisely the same types: for |
| // example, they will probably each declare their own structs, |
| // which are distinct types from LLVM's point of view (nominal |
| // types). |
| // |
| // Now, if those two crates are linked into an application, and |
| // they contain inlined code, you can wind up with a situation |
| // where both of those functions wind up being loaded into this |
| // application simultaneously. In that case, the same function |
| // (from LLVM's point of view) requires two types. But of course |
| // LLVM won't allow one function to have two types. |
| // |
| // What we currently do, therefore, is declare the function with |
| // one of the two types (whichever happens to come first) and then |
| // bitcast as needed when the function is referenced to make sure |
| // it has the type we expect. |
| // |
| // This can occur on either a crate-local or crate-external |
| // reference. It also occurs when testing libcore and in some |
| // other weird situations. Annoying. |
| |
| let sym = ccx.symbol_map().get_or_compute(ccx.shared(), |
| TransItem::Fn(instance)); |
| |
| let llptrty = type_of::type_of(ccx, fn_ptr_ty); |
| let llfn = if let Some(llfn) = declare::get_declared_value(ccx, &sym) { |
| if let Some(span) = local_item { |
| if declare::get_defined_value(ccx, &sym).is_some() { |
| ccx.sess().span_fatal(span, |
| &format!("symbol `{}` is already defined", &sym)); |
| } |
| } |
| |
| if common::val_ty(llfn) != llptrty { |
| if local_item.is_some() { |
| bug!("symbol `{}` previously declared as {:?}, now wanted as {:?}", |
| sym, Value(llfn), llptrty); |
| } |
| debug!("get_fn: casting {:?} to {:?}", llfn, llptrty); |
| consts::ptrcast(llfn, llptrty) |
| } else { |
| debug!("get_fn: not casting pointer!"); |
| llfn |
| } |
| } else { |
| let llfn = declare::declare_fn(ccx, &sym, ty); |
| assert_eq!(common::val_ty(llfn), llptrty); |
| debug!("get_fn: not casting pointer!"); |
| |
| let attrs = ccx.tcx().get_attrs(def_id); |
| attributes::from_fn_attrs(ccx, &attrs, llfn); |
| if local_item.is_some() { |
| // FIXME(eddyb) Doubt all extern fn should allow unwinding. |
| attributes::unwind(llfn, true); |
| } |
| |
| llfn |
| }; |
| |
| ccx.instances().borrow_mut().insert(instance, llfn); |
| |
| immediate_rvalue(llfn, fn_ptr_ty) |
| } |
| |
| // ______________________________________________________________________ |
| // Translating calls |
| |
| fn trans_call_inner<'a, 'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>, |
| debug_loc: DebugLoc, |
| callee: Callee<'tcx>, |
| args: CallArgs<'a, 'tcx>, |
| dest: Option<expr::Dest>) |
| -> Result<'blk, 'tcx> { |
| // Introduce a temporary cleanup scope that will contain cleanups |
| // for the arguments while they are being evaluated. The purpose |
| // this cleanup is to ensure that, should a panic occur while |
| // evaluating argument N, the values for arguments 0...N-1 are all |
| // cleaned up. If no panic occurs, the values are handed off to |
| // the callee, and hence none of the cleanups in this temporary |
| // scope will ever execute. |
| let fcx = bcx.fcx; |
| let ccx = fcx.ccx; |
| |
| let abi = callee.ty.fn_abi(); |
| let sig = callee.ty.fn_sig(); |
| let output = bcx.tcx().erase_late_bound_regions(&sig.output()); |
| let output = bcx.tcx().normalize_associated_type(&output); |
| |
| let extra_args = match args { |
| ArgExprs(args) if abi != Abi::RustCall => { |
| args[sig.0.inputs.len()..].iter().map(|expr| { |
| common::expr_ty_adjusted(bcx, expr) |
| }).collect() |
| } |
| _ => vec![] |
| }; |
| let fn_ty = callee.direct_fn_type(ccx, &extra_args); |
| |
| let mut callee = match callee.data { |
| Intrinsic => { |
| assert!(abi == Abi::RustIntrinsic || abi == Abi::PlatformIntrinsic); |
| assert!(dest.is_some()); |
| |
| return intrinsic::trans_intrinsic_call(bcx, callee.ty, &fn_ty, |
| args, dest.unwrap(), |
| debug_loc); |
| } |
| NamedTupleConstructor(disr) => { |
| assert!(dest.is_some()); |
| |
| return base::trans_named_tuple_constructor(bcx, |
| callee.ty, |
| disr, |
| args, |
| dest.unwrap(), |
| debug_loc); |
| } |
| f => f |
| }; |
| |
| // Generate a location to store the result. If the user does |
| // not care about the result, just make a stack slot. |
| let opt_llretslot = dest.and_then(|dest| match dest { |
| expr::SaveIn(dst) => Some(dst), |
| expr::Ignore => { |
| let needs_drop = || match output { |
| ty::FnConverging(ret_ty) => bcx.fcx.type_needs_drop(ret_ty), |
| ty::FnDiverging => false |
| }; |
| if fn_ty.ret.is_indirect() || fn_ty.ret.cast.is_some() || needs_drop() { |
| // Push the out-pointer if we use an out-pointer for this |
| // return type, otherwise push "undef". |
| if fn_ty.ret.is_ignore() { |
| Some(C_undef(fn_ty.ret.original_ty.ptr_to())) |
| } else { |
| let llresult = alloca(bcx, fn_ty.ret.original_ty, "__llret"); |
| call_lifetime_start(bcx, llresult); |
| Some(llresult) |
| } |
| } else { |
| None |
| } |
| } |
| }); |
| |
| // If there no destination, return must be direct, with no cast. |
| if opt_llretslot.is_none() { |
| assert!(!fn_ty.ret.is_indirect() && fn_ty.ret.cast.is_none()); |
| } |
| |
| let mut llargs = Vec::new(); |
| |
| if fn_ty.ret.is_indirect() { |
| let mut llretslot = opt_llretslot.unwrap(); |
| if let Some(ty) = fn_ty.ret.cast { |
| llretslot = PointerCast(bcx, llretslot, ty.ptr_to()); |
| } |
| llargs.push(llretslot); |
| } |
| |
| let arg_cleanup_scope = fcx.push_custom_cleanup_scope(); |
| bcx = trans_args(bcx, abi, &fn_ty, &mut callee, args, &mut llargs, |
| cleanup::CustomScope(arg_cleanup_scope)); |
| fcx.scopes.borrow_mut().last_mut().unwrap().drop_non_lifetime_clean(); |
| |
| let llfn = match callee { |
| Fn(f) => f, |
| _ => bug!("expected fn pointer callee, found {:?}", callee) |
| }; |
| |
| let (llret, mut bcx) = base::invoke(bcx, llfn, &llargs, debug_loc); |
| if !bcx.unreachable.get() { |
| fn_ty.apply_attrs_callsite(llret); |
| |
| // If the function we just called does not use an outpointer, |
| // store the result into the rust outpointer. Cast the outpointer |
| // type to match because some ABIs will use a different type than |
| // the Rust type. e.g., a {u32,u32} struct could be returned as |
| // u64. |
| if !fn_ty.ret.is_indirect() { |
| if let Some(llretslot) = opt_llretslot { |
| fn_ty.ret.store(&bcx.build(), llret, llretslot); |
| } |
| } |
| } |
| |
| fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_cleanup_scope); |
| |
| // If the caller doesn't care about the result of this fn call, |
| // drop the temporary slot we made. |
| match (dest, opt_llretslot, output) { |
| (Some(expr::Ignore), Some(llretslot), ty::FnConverging(ret_ty)) => { |
| // drop the value if it is not being saved. |
| bcx = glue::drop_ty(bcx, llretslot, ret_ty, debug_loc); |
| call_lifetime_end(bcx, llretslot); |
| } |
| _ => {} |
| } |
| |
| if output == ty::FnDiverging { |
| Unreachable(bcx); |
| } |
| |
| Result::new(bcx, llret) |
| } |
| |
| pub enum CallArgs<'a, 'tcx> { |
| /// Supply value of arguments as a list of expressions that must be |
| /// translated. This is used in the common case of `foo(bar, qux)`. |
| ArgExprs(&'a [P<hir::Expr>]), |
| |
| /// Supply value of arguments as a list of LLVM value refs; frequently |
| /// used with lang items and so forth, when the argument is an internal |
| /// value. |
| ArgVals(&'a [ValueRef]), |
| |
| /// For overloaded operators: `(lhs, Option(rhs))`. |
| /// `lhs` is the left-hand-side and `rhs` is the datum |
| /// of the right-hand-side argument (if any). |
| ArgOverloadedOp(Datum<'tcx, Expr>, Option<Datum<'tcx, Expr>>), |
| |
| /// Supply value of arguments as a list of expressions that must be |
| /// translated, for overloaded call operators. |
| ArgOverloadedCall(Vec<&'a hir::Expr>), |
| } |
| |
| fn trans_args_under_call_abi<'blk, 'tcx>( |
| mut bcx: Block<'blk, 'tcx>, |
| arg_exprs: &[P<hir::Expr>], |
| callee: &mut CalleeData, |
| fn_ty: &FnType, |
| llargs: &mut Vec<ValueRef>, |
| arg_cleanup_scope: cleanup::ScopeId) |
| -> Block<'blk, 'tcx> |
| { |
| let mut arg_idx = 0; |
| |
| // Translate the `self` argument first. |
| let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &arg_exprs[0])); |
| bcx = trans_arg_datum(bcx, |
| arg_datum, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| |
| // Now untuple the rest of the arguments. |
| let tuple_expr = &arg_exprs[1]; |
| let tuple_type = common::node_id_type(bcx, tuple_expr.id); |
| |
| match tuple_type.sty { |
| ty::TyTuple(ref field_types) => { |
| let tuple_datum = unpack_datum!(bcx, |
| expr::trans(bcx, &tuple_expr)); |
| let tuple_lvalue_datum = |
| unpack_datum!(bcx, |
| tuple_datum.to_lvalue_datum(bcx, |
| "args", |
| tuple_expr.id)); |
| let repr = adt::represent_type(bcx.ccx(), tuple_type); |
| let repr_ptr = &repr; |
| for (i, field_type) in field_types.iter().enumerate() { |
| let arg_datum = tuple_lvalue_datum.get_element( |
| bcx, |
| field_type, |
| |srcval| { |
| adt::trans_field_ptr(bcx, repr_ptr, srcval, Disr(0), i) |
| }).to_expr_datum(); |
| bcx = trans_arg_datum(bcx, |
| arg_datum, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| } |
| } |
| _ => { |
| span_bug!(tuple_expr.span, |
| "argument to `.call()` wasn't a tuple?!") |
| } |
| }; |
| |
| bcx |
| } |
| |
| pub fn trans_args<'a, 'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
| abi: Abi, |
| fn_ty: &FnType, |
| callee: &mut CalleeData, |
| args: CallArgs<'a, 'tcx>, |
| llargs: &mut Vec<ValueRef>, |
| arg_cleanup_scope: cleanup::ScopeId) |
| -> Block<'blk, 'tcx> { |
| debug!("trans_args(abi={})", abi); |
| |
| let _icx = push_ctxt("trans_args"); |
| |
| let mut bcx = bcx; |
| let mut arg_idx = 0; |
| |
| // First we figure out the caller's view of the types of the arguments. |
| // This will be needed if this is a generic call, because the callee has |
| // to cast her view of the arguments to the caller's view. |
| match args { |
| ArgExprs(arg_exprs) => { |
| if abi == Abi::RustCall { |
| // This is only used for direct calls to the `call`, |
| // `call_mut` or `call_once` functions. |
| return trans_args_under_call_abi(bcx, |
| arg_exprs, callee, fn_ty, |
| llargs, |
| arg_cleanup_scope) |
| } |
| |
| for arg_expr in arg_exprs { |
| let arg_datum = unpack_datum!(bcx, expr::trans(bcx, &arg_expr)); |
| bcx = trans_arg_datum(bcx, |
| arg_datum, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| } |
| } |
| ArgOverloadedCall(arg_exprs) => { |
| for expr in arg_exprs { |
| let arg_datum = |
| unpack_datum!(bcx, expr::trans(bcx, expr)); |
| bcx = trans_arg_datum(bcx, |
| arg_datum, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| } |
| } |
| ArgOverloadedOp(lhs, rhs) => { |
| bcx = trans_arg_datum(bcx, lhs, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| |
| if let Some(rhs) = rhs { |
| bcx = trans_arg_datum(bcx, rhs, |
| callee, fn_ty, &mut arg_idx, |
| arg_cleanup_scope, |
| llargs); |
| } |
| } |
| ArgVals(vs) => { |
| match *callee { |
| Virtual(idx) => { |
| llargs.push(vs[0]); |
| |
| let fn_ptr = meth::get_virtual_method(bcx, vs[1], idx); |
| let llty = fn_ty.llvm_type(bcx.ccx()).ptr_to(); |
| *callee = Fn(PointerCast(bcx, fn_ptr, llty)); |
| llargs.extend_from_slice(&vs[2..]); |
| } |
| _ => llargs.extend_from_slice(vs) |
| } |
| } |
| } |
| |
| bcx |
| } |
| |
| fn trans_arg_datum<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, |
| arg_datum: Datum<'tcx, Expr>, |
| callee: &mut CalleeData, |
| fn_ty: &FnType, |
| next_idx: &mut usize, |
| arg_cleanup_scope: cleanup::ScopeId, |
| llargs: &mut Vec<ValueRef>) |
| -> Block<'blk, 'tcx> { |
| let _icx = push_ctxt("trans_arg_datum"); |
| let mut bcx = bcx; |
| |
| debug!("trans_arg_datum({:?})", arg_datum); |
| |
| let arg = &fn_ty.args[*next_idx]; |
| *next_idx += 1; |
| |
| // Fill padding with undef value, where applicable. |
| if let Some(ty) = arg.pad { |
| llargs.push(C_undef(ty)); |
| } |
| |
| // Determine whether we want a by-ref datum even if not appropriate. |
| let want_by_ref = arg.is_indirect() || arg.cast.is_some(); |
| |
| let fat_ptr = common::type_is_fat_ptr(bcx.tcx(), arg_datum.ty); |
| let (by_ref, val) = if fat_ptr && !bcx.fcx.type_needs_drop(arg_datum.ty) { |
| (true, arg_datum.val) |
| } else { |
| // Make this an rvalue, since we are going to be |
| // passing ownership. |
| let arg_datum = unpack_datum!( |
| bcx, arg_datum.to_rvalue_datum(bcx, "arg")); |
| |
| // Now that arg_datum is owned, get it into the appropriate |
| // mode (ref vs value). |
| let arg_datum = unpack_datum!(bcx, if want_by_ref { |
| arg_datum.to_ref_datum(bcx) |
| } else { |
| arg_datum.to_appropriate_datum(bcx) |
| }); |
| |
| // Technically, ownership of val passes to the callee. |
| // However, we must cleanup should we panic before the |
| // callee is actually invoked. |
| (arg_datum.kind.is_by_ref(), |
| arg_datum.add_clean(bcx.fcx, arg_cleanup_scope)) |
| }; |
| |
| if arg.is_ignore() { |
| return bcx; |
| } |
| |
| debug!("--- trans_arg_datum passing {:?}", Value(val)); |
| |
| if fat_ptr { |
| // Fat pointers should be passed without any transformations. |
| assert!(!arg.is_indirect() && arg.cast.is_none()); |
| llargs.push(Load(bcx, expr::get_dataptr(bcx, val))); |
| |
| let info_arg = &fn_ty.args[*next_idx]; |
| *next_idx += 1; |
| assert!(!info_arg.is_indirect() && info_arg.cast.is_none()); |
| let info = Load(bcx, expr::get_meta(bcx, val)); |
| |
| if let Virtual(idx) = *callee { |
| // We have to grab the fn pointer from the vtable when |
| // handling the first argument, ensure that here. |
| assert_eq!(*next_idx, 2); |
| assert!(info_arg.is_ignore()); |
| let fn_ptr = meth::get_virtual_method(bcx, info, idx); |
| let llty = fn_ty.llvm_type(bcx.ccx()).ptr_to(); |
| *callee = Fn(PointerCast(bcx, fn_ptr, llty)); |
| } else { |
| assert!(!info_arg.is_ignore()); |
| llargs.push(info); |
| } |
| return bcx; |
| } |
| |
| let mut val = val; |
| if by_ref && !arg.is_indirect() { |
| // Have to load the argument, maybe while casting it. |
| if arg.original_ty == Type::i1(bcx.ccx()) { |
| // We store bools as i8 so we need to truncate to i1. |
| val = LoadRangeAssert(bcx, val, 0, 2, llvm::False); |
| val = Trunc(bcx, val, arg.original_ty); |
| } else if let Some(ty) = arg.cast { |
| val = Load(bcx, PointerCast(bcx, val, ty.ptr_to())); |
| if !bcx.unreachable.get() { |
| let llalign = llalign_of_min(bcx.ccx(), arg.ty); |
| unsafe { |
| llvm::LLVMSetAlignment(val, llalign); |
| } |
| } |
| } else { |
| val = Load(bcx, val); |
| } |
| } |
| |
| llargs.push(val); |
| bcx |
| } |
